title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
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Assessing emergency response training needs of local environmental health professionals. | The Michigan Center for Public Health Preparedness collaborated with environmental health (EH) professionals at the local, state, and national levels to develop and conduct a state-wide study to identify the preparedness-training needs of local EH professionals in Michigan. The specific aims of the study were first, to determine the self-rated level of confidence among Michigan's EH professionals regarding relevant emergency planning and response competencies; second, to determine the specific preparedness training topic preferences of Michigan's EH professionals; and third, to establish baseline needs assessment data to be used to track progress toward higher levels of readiness after implementation of planning, training, and other preparedness activities. The study recruited 400 EH professionals to complete the survey (61% of all EH professionals in 45 local health departments in Michigan). The top training topic preferences were "environmental health role in emergencies" followed by "water security" and "food security." The EH professionals rated their confidence in demonstrating relevant emergency planning and response competencies. Most of the average ratings (on a 5-point scale) were close to the scale's middle point (rating = 3), suggesting that EH professionals rate themselves as "somewhat confident" in performing important tasks in preparedness and response. Variations in specific ratings helped identify training needs. The discussion of these results focused on the implications of this study for the development of emergency response training for environmental health professionals. | 18,807,819 |
The impact of legislation in Ireland on handheld mobile phone use by drivers. | Under the Road Traffic Act, 2006 handheld mobile phone use whilst driving is an offence liable to a fine and penalty points. The aim of this study was to determine whether there has been a change in driver behaviour following the introduction of this legislation. This study found that 2.3% of drivers were still using a handheld mobile phone. | 18,807,816 |
A primer in the evaluation of quality in acute care settings. | Nurses are in a unique position to evaluate acute care quality. The authors describe common problems and challenges related to selection of variables and choice of databases for quality evaluations. Practical strategies to address these concerns also are discussed. | 18,807,858 |
[The morbidity of physicians of pre-pensionary age]. | The data research related to the investigation of the morbidity of the physicians of pre-pensionary age on the basis of medical check-up results. It is established that more than 95% of physicians suffered from chronic diseases. At that most of them had several diseases. Among the examined groups of physicians according their gender, age and duration of work in the medicine the most morbid were the physicians older than 50 years and with the period of probation 25 years and more. In the structure of the revealed pathology leading role was played by the cardiovascular diseases, the diseases of musculo-skeletal system, the diseases of the eye and its supplementary apparatus, the respiratory diseases and the diseases of urogenital system. The revealed characteristics of morbidity are to be taken into account at the development of the group and individual programs of preservation, rehabilitation and promotion of physicians' health. | 18,807,868 |
[Immunohistochemical analysis of hepatic steatosis in autopsy cases of severe motor and intellectual disabilities]. | To explore the pathogenesis of hepatic steatosis in severe motor and intellectual disabilities (SMID), we immunohistochemically examined the accumulation of oxidative products in 8 autopsy cases of SMID, 5 of which pathologically showed hepatic steatosis. Three of the 8 cases also demonstrated fibrosis in Glisson's sheath. Serial sections of liver were treated with monoclonal antibodies to oxidative products to proteins, lipids and nucleosides. Immunoreactivity for 4-hydroxynonenal, a marker of oxidative damage to lipids, was increased in the cytoplasm of hepatocytes in 5 cases; 2 with steatosis plus fibrosis, one with only fibrosis, and 2 with only hepatic steatosis. One case showed immunoreactivity for advanced glycation endproduct, a marker of oxidative damage to protein, in hepatocytes. There was no immunoreactivity for 8-hydroxy-2'-deoxyguanosine and hexanoyl lysine, markers of oxidative damage to DNA and lipids, respectively. These findings partly mimic those observed in adult patients with nonalcoholic steatohepatitis. The results suggested the involvement of oxidative damage to lipids in the pathogenesis of hepatic steatosis and/or fibrosis in patients with SMID. | 18,807,886 |
[Mitochondrial diseases in children including Leigh syndrome--biochemical and molecular background]. | Mitochondrial diseases in children are more frequently caused by mutations in nuclear DNA then in mtDNA. Special clinical phenotypes are associated with the mutations in SURF1 gene, in SCO2 gene and with mtDNA depletion syndromes. Leigh syndrome is the most common clinical presentation of various mitochondrial disorders during childhood. Elevation of lactate in blood, cerebrospinal fluid and urine is a simple biochemical marker of mitochondrial disorders but its specificity and sensitivity are low. Biochemical investigation of muscle biopsy and search for mitochondrial mutations remain a gold standard in the diagnosis. The standarized diagnostic criteria to establish level of diagnostic certainty (possible, probable, definite) are proposed to be used in practice; these include clinical features, neuroimaging and muscle biopsy investigations. Further research directions to improve our understanding of mitochondrial pathologies in children are suggested. | 18,807,927 |
[Protein kinases in mitochondria]. | Mitochondria, besides playing a central role in energy metabolism within the cell, are involved in a cohort of other processes like cellular differentiation and apoptosis. Investigations during recent few years have shown that protein kinases, including PKA, PKB/Akt, PKC, Raf-1, p38 MAPK, JNK, ERK1/2, Src, Fyn and Csk, may directly interact with mitochondrial proteins. Their role mainly concentrates at phosphorylation of pro- and anti-apoptotic proteins (Bad, Bax, Bcl-2, Bcl-xL), phosphorylation/modification of electron transport chain proteins (complex I, COIV), MPTP forming proteins VDAC and ANT, proteins of mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) and phospholipid scramblase 3 (PLSCR3). Many experimental data showed the presence of protein kinases in the outer and inner mitochondrial membranes as well as in the mitochondrial matrix during in vitro cell stimulations, in neurodegenerative diseases and in in vivo ischaemia heart preconditioning. These data show that translocation of protein kinases to mitochondria plays an important role especially during ischaemia/reperfusion in brain and heart. | 18,807,932 |
[Metabolic engineering for improving ethanol fermentation of xylose by wild yeast]. | One yeast strain, which was isolated from 256 natural samples, was found to be able to utilize D-xylose effectively. On the basis of assimilation physiological and molecular biological tests, the yeast strain was identified as a strain of Candida tropicalis. Furthermore, metabolic engineering breeding strategy was applied to change the metabolic flux in order to increase ethanol productivity. In this study, the C. tropicalis was used as the host strain and the plasmid pYX212-XYL2, which was formerly constructed for over expression of XYL2 gene encoding xylitol dehydrogenase (XDH) from Pichia stipitis, was used as the backbone of the recombinant vector. A hygro gene was inserted into downstream position of XYL2 gene, meanwhile, the result plasmid pXY212-XYL2-Hygro transformed into C. tropicalis by electroporation. Thus, a recombinant yeast C. tropicalis XYL2-7 was obtained through hygromycin B resistance screening and its specific XDH activity was 0.5 u/mg protein, which was 3 times more than that of the parent strain. Additionally, the recombinant yeast was applied in the fermentation of xylose. Compared with the parent yeast, it was concluded that the xylitol yield in the broth decreased by 3 times, however, the ethanol yield increased by 5 times. The feasibility of ethanol production from xylose by C. tropicalis was firstly studied in this paper. These research results are helpful to advance the bioconversion of renewable resources (e. g. straw, wheat bran, and husk) to fuel ethanol. | 18,807,975 |
[Gene function and microbial community structure in sulfide minerals bioleaching system based on microarray analysis]. | Biohydrometallergy technology received more and more attention because of its simple process, low cost and kind to environment, especially in dealing with low-grade and complex minerals. However, it is difficult to optimize microorganism species and process parameters in bioleaching procedure because of the lack of suitable bacteria and quantitative analysis methods at micro-level for bioleaching system. This has resulted in the low efficiency and poor yield of the target metal in bioleaching. With the development of microarray and bacteria conservation technology, solutions to the above problems were being found. This article summarizes the latest findings on genetic elucidation and the community structure of microorganisms in sulfide minerals bioleaching system, in the aim of providing a better understanding on the significance of cross-field technology of biohydrometallergy and genomics. | 18,807,978 |
[Isolation and fermentation condition of milk-clotting enzyme producing strain from glutinous rice wine]. | Glutinous rice wine is a traditional food in south of China and it can coagulate milk. It has been proved that its function of coagulating milk is because of the presence of milk-clotting enzyme produced by microorganisms in glutinous rice wine. The aim of this work is to isolate milk-clotting enzyme producing strain from glutinous rice wine and study the fermentation condition. We screened out four bacteria and fungus by gradient dilution. It was proved that mold played the most important role in the production of milk-clotting enzyme. This is further confirmed by casein plate method. The optimization of fermentation conditions revealed that two times concentrated potato medium supplemented with 5% glucose without additional nitrogen was better for production of the enzyme. The enzyme activity was increased 144% under the conditions established. | 18,807,982 |
[Purification and characterization of extracellular polysaccharides from Nostoc flagelliforme]. | The extracellular polysaccharides (EPS) of N. flagelliforme were purified by DEAE anion exchange chromatography and Sephadex G100 gel filtration chromatography. And two main components named NFPS1 and NFPS2 were obtained respectively. The physico-chemical characteristics of NFPS2 were analyzed and compared with NFPS0, which was obtained from field colony of N. flagelliforme. These results showed that both of NFPS2 and NFPSO were composed of four monosaccharides: glucose, xylose, galactose and mannose. The apparent molecular weight of NFPS2 and NFPS0 was estimated to be 2.79 x 10(5), 2.26 x 10(5) respectively. They are non-sulfated polysaccharides, free of protein and nuclear acid. The thermal analysis indicated that there was a decomposition peak at 245 degrees C in thermogravimetric (TG) curves. However, the microstructure analysis showed that they had different porous structures. | 18,807,987 |
[Dynamics of initial decomposition of Calamagrostis angustifolia litter in Sanjiang Plain of China]. | A 28-day leaching-decomposition experiment was conducted to study the effects of microbial activity and leaching on the initial decomposition of Calamagrostis angustifolia litters taken from the boggy meadow and meadow in Sanjiang Plain of China. The results showed that the mass loss of the litters at their initial decomposition stage accounted for 59% and 22% of yearly mass loss, respectively, and the remaining dry mass decreased significantly after 28-day decomposition. By the end of the experiment, the N content in the litters decreased by 32.65% and 24.55% , and P content decreased by 36.71% and 45.15%, respectively. The N and P contents in the litters treated with chloroform were higher than those of the control, but the difference was not significant. No significant difference was also observed in the N and P release from the litters to the leachates between the treatment of chloroform and CK, which indicated that the initial decomposition of the litters was mainly affected by leaching. There was no significant difference in the decomposition rate and nutrient loss rate between the two litters. | 18,808,011 |
[Chemical forms and ecological effect of soil Mn in liver cancer's high incidence area in Zhu-jiang River Delta, China]. | The samples of surface soil, deep soil, and vegetables were collected from the liver cancer's high- and low incidence areas in Zhujiang River Delta to study the relationships between soil Mn forms and vegetables' Mn enrichment. The results showed that the soil Mn in study area was mainly derived from parent materials, and rarely come from human activities. The average soil Mn content in liver cancer's high incidence area was 577.65 mg x kg(-1), being significantly lower than that of liver cancer's low incidence area (718.04 mg x kg(-1)) and whole country (710 mg x kg(-1)). The Mn forms in high incidence area were mainly of residual Mn and Fe-Mn oxide, and less of water soluble Mn and exchangeable Mn, with the sum of the latter two's distribution coefficients being not higher than 4%. In low incidence area, the distribution pattern of soil Mn forms was similar to that in high incidence area, but the absolute contents of the Mn forms were significantly higher. Soil total Mn and soil pH had significant effects on soil Mn forms. There existed significant positive correlations between soil total Mn and the Mn forms of Fe-Mn bound, humic acid bound, carbonate bound, and residual, and negative correlations between soil pH and soil water soluble and organic bound Mn forms. Among the test five kinds of vegetables, Youmai lettuce and Chinese cabbage in liver cancer' s high incidence area had a significantly lower Mn content than in low incidence area, while the other three had less difference. The Mn enrichment in test vegetables was positively correlated with to the content of soil available Mn (sum of water soluble Mn and exchangeable Mn), but had no correlations with the contents of soil total Mn and other Mn forms. | 18,808,033 |
Expression of c-Myc, neurofibromatosis Type 2, somatostatin receptor 2 and erb-B2 in human meningiomas: relation to grades or histotypes. | Meningiomas, which originate from arachnoid cells, represent one of the largest subgroups of intracranial tumors. They are generally benign, but can progress to malignancy. The aim of our study was to determine the expression of 4 genes, c-Myc, neurofibromatosis Type 2 (NF2), somatostatin receptor isoform 2 (sst2) and erb-B2, that have been associated with tumorogenesis or, possibly, with aggressive behavior or recurrence of meningiomas. We measured levels of mRNAs coding for these genes by qRT-PCR in 51 cases and levels ofc-Myc protooncogene and sst2 protein by immunohistochemistry in 26 cases of meningiomas of various grades and histotypes. C-Myc mRNA and protein levels were not grade-related, but validated subdivision of the 36 benign meningiomas into two groups, Groups IA and IB, based on histological and clinical features (Ki-67-proliferative index, absence or presence of mitoses, rate of recurrence and incidence of perilesional edema). In addition to histopathological grading, c-Myc expression may be useful in predicting tumor recurrence in patients with low-grade meningiomas. NF2 mRNA levels and sst2 mRNA and receptor levels were not grade-related, but were histotype-related, with significantly higher levels in the meningothelial subtype than in the fibroblastic subtype. Erb-B2 mRNA levels were not grade- or histotype-related. Furthermore, the high expression of sst2 in meningothelial meningioma suggests the possibility of a different tumorigenesis process in this meningioma subtype and may open perspectives for the diagnosis and therapy of this subtype using somatostatin as an antiproliferative agent. | 18,808,065 |
[Ticks--due to climatic changes, much more than just Ixodes ricinus, TBE and Lyme disease]. | Ectoparasitic arthropodes, like ticks, confer numerous pathogenic bacterial and viral germs upon human beings and/or animals. Since these vectors are poikilothermic, there is a strong dependence on environmental conditions. Climatic as well as microclimatic conditions play a major role. Against this background, it can be anticipated that climatic changes also influence the bionomics of ticks and of the pathogens conferred by them. | 18,808,072 |
[Antimycotic therapy of Tinea pedis and other foot mycoses]. | Fungal foot infections belong to the most frequent infectious diseases in industrialized countries. In Germany, an estimated one third of the total adult population is suffering from a mycosis of the foot. In most cases, these infections are caused by a dermatophyte species, especially Trichophyton rubrum and T. mentagrophytes, and affect the toes and the areas between the toes, respectively, and/or the soles of the foot (Tinea pedis). In some cases, foot infections due to other fungi than dermatophytes (predominantly Candida spp.) have been described. Based on underlying symptoms and localization of the infection, there are three principal forms of foot mycoses. The most common type is the intertriginous type characterized by peeling, maceration and fissuring mostly affecting the lateral toe clefts. The rarer vesiculobullous form is characterized by vesicles and blisters often located on the soles. The squamous hyperkeratotic form, referred to as moccasin type in its extensive form, affects the soles, heels and lateral sites. If there is no extensive spread of infection, intertriginous and vesiculobullous forms can be generally successfully treated with topical antimycotics. The squamous hyperkeratotic form, however, should be treated by simultaneous application of topical and systemic antifungals. Because of the prescription discharge of a range of topical antimycotics, the advisory function of pharmacists is vitally important. In Germany, self-medication with "over the counter" antifungals is carried out using a range of different topical agents, in particular several azole derivatives and the allylamine terbinafine. The allylamine naftifine, the morpholine amorolfine and the pyridinone derivative ciclopiroxolamine are also applied. For systemic treatment, systemically applicable azole antifungals (fluconazole, itraconazole), terbinafine and griseofulvine are in use. | 18,808,073 |
Oxidation of cyclohexane by a high-valent iron bispidine complex: a combined experimental and computational mechanistic study. | Experimental data suggest that there are various competing pathways for the catalytic and stoichiometric oxygenation of cyclohexane, assisted by iron-bispidine complexes and using various oxidants (H(2)O(2), O(2), PhIO). Density functional theory calculations indicate that both Fe(IV)=O and Fe(V)=O species are accessible and efficiently transfer their oxygen atoms to cyclohexane. The reactivities of the two isomers each and the two possible spin states for the Fe(IV)=O and Fe(V)=O species are sufficiently different to allow an interpretation of the experimental data. | 18,808,102 |
Near-quantitative internal quantum efficiency in a light-emitting electrochemical cell. | A green-light-emitting iridium(III) complex was prepared that has a photoluminescence quantum yield in a thin-film configuration of almost unity. When used in a simple solid-state single-layer light-emitting electrochemical cell, it yielded an external quantum efficiency of nearly 15% and a power efficiency of 38 Lm/W. We argue that these high external efficiencies are only possible if near-quantitative internal electron-to-photon conversion occurs. This shows that the limiting factor for the efficiency of these devices is the photoluminescence quantum yield in a solid film configuration. The observed efficiencies show the prospect of these simple electroluminescent devices for lighting and signage applications. | 18,808,114 |
Electronic structure and magnetism in transition metals doped 8-hydroxy-quinoline aluminum. | We report the room-temperature ferromagnetism in transition metals (Co, Ni)-doped 8-hydroxy-quinoline aluminum (Alq3) by thermal coevaporation of high purity metal and Alq3 powders. For 5% Co-doped Alq3, a maximum magnetization of approximately 0.33 microB/Co at 10 K was obtained and ferromagnetic behavior was observed up to 300 K. The Co atoms interact chemically with O atoms and provide electrons to Alq3, forming new states acting as electron trap sites. From this, it is suggested that ferromagnetism may be associated with the strong chemical interaction of Co atoms and Alq3 molecules. | 18,808,121 |
Studies on the synthesis of durhamycin A: stereoselective synthesis of a model aglycone. | A stereoselective synthesis of the model aglycone corresponding to the anti-HIV aureolic acids durhamycins A (1) and B (2) is described. | 18,808,128 |
Palladium-catalyzed benzylic arylation of N-benzylxanthone imine. | The direct benzylic arylation of N-benzylxanthone imine with aryl chloride proceeds under palladium catalysis, yielding the corresponding coupling product. The product is readily transformed to benzhydrylamine. Taking into consideration that the imine is readily available from benzylic amine, the overall transformation represents a formal cross-coupling reaction of aryl halide with alpha-aminobenzyl metal. | 18,808,130 |
Facile preparation of alpha-aryl nitriles by direct cyanation of alcohols with TMSCN under the catalysis of InX3. | A convenient and efficient synthesis of alpha-aryl nitriles was developed by direct cyanation of alcohols with TMSCN under the catalysis of Lewis acid. Using 5-10 mol % of InBr3 as the catalyst, a variety of benzylic alcohols can be converted to the corresponding nitriles in 5-30 min with yields of 46-99%. | 18,808,133 |
A light-harvesting array composed of porphyrins and rigid backbones. | A light-harvesting array containing rigid backbones, peripherally positioned Zn-porphyrin terminals, and a free-base (Fb) porphyrin core was prepared by a convergent method where the Sonogashira coupling reaction was used in the key steps. Effective intramolecular singlet-energy transfer from the peripheral Zn-porphyrin units to the Fb porphyrin core was observed. The efficiency of the energy transfer was compared with those of reference compounds. | 18,808,134 |
Platinum-catalyzed enantioselective tandem alkylation/arylation of primary phosphines. Asymmetric synthesis of P-stereogenic 1-phosphaacenaphthenes. | Enantioselective tandem alkylation/arylation of primary phosphines with 1-bromo-8-chloromethylnaphthalene catalyzed by Pt(DuPhos) complexes gave P-stereogenic 1-phosphaacenaphthenes (AcePhos) in up to 74% ee. Diastereoselective formation of four P-C bonds in one pot with bis(primary) phosphines gave C2-symmetric diphosphines, including the o-phenylene derivative DuAcePhos, for which the rac isomer was formed with high enantioselectivity. These reactions, which appear to proceed via an unusual metal-mediated nucleophilic aromatic substitution pathway, yield a new class of heterocycles with potential applications in asymmetric catalysis. | 18,808,136 |
N-(p-dodecylphenylsulfonyl)-2-pyrrolidinecarboxamide: a practical proline mimetic for facilitating enantioselective aldol reactions. | A highly practical and readily available proline surrogate has been developed with improved solubility properties in common, nonpolar organic solvents. This sulfonamide-based catalyst has proven highly effective at facilitating enantioselective and diastereoselective aldol reactions with a range of substrates in nonpolar organic solvents in the presence of a single equivalent of water. Additionally, catalyst loading as low as 2 mol % can be employed in the absence of any organic solvent with continued high levels of selectivity. | 18,808,137 |
Angiotensin I-converting enzyme-inhibitory peptides obtained from chicken collagen hydrolysate. | In this study, collagen extracted from chicken legs (which are the yellow keratin parts containing a nail) was hydrolyzed with various enzymes, and the angiotensin I-converting enzyme (ACE)-inhibitory activity of each hydrolysate was determined. The hydrolysate by treatment with an Aspergillus species-derived enzyme had the highest activity (IC 50 = 260 microg/mL). The fraction of this hydrolysate obtained by ultrafiltration with a molecular-weight cutoff of 3000 Da (low fraction) had a stronger activity (IC 50 = 130 microg/mL) than the fractionated one. This fraction was further fractionated by HPLC, and the peptides in the fraction with high ACE-inhibitory activity were identified. The amino acid sequences of the four peptides were identified using a protein sequencer. These peptides were synthesized to confirm their ACE-inhibitory activities; this showed that peptides with a Gly-Ala-Hyp-Gly-Leu-Hyp-Gly-Pro sequence had the highest activity (IC 50 = 29 microM). When the low fraction was administered to spontaneous hypertensive rats, a decrease in their blood pressure was observed after 2 h of administration, and a significant decrease in blood pressure (-50 mmHg) was observed after 6 h. Moreover, long-term administration studies indicated that the low fraction showed a significant suppression of increased blood pressure. | 18,808,143 |
Angelica sinensis and its alkylphthalides induce the detoxification enzyme NAD(P)H: quinone oxidoreductase 1 by alkylating Keap1. | The roots of Angelica sinensis (Oliv.) Diels (Dang Gui; Apiaceae) have a long history in traditional Chinese medicine as a remedy for women's disorders and are often called "lady's ginseng". Currently, extracts of A. sinensis are commonly included in numerous dietary supplements used for women's health and as antiaging products. In the present study, we examined the potential chemopreventive activity of A. sinensis extracts by measuring the relative ability to induce the detoxification enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO1). The lipophilic partitions showed strong NQO1 induction with concentrations to double the enzyme activity (CD) of 5.5 +/- 0.7 (petroleum ether) and 3.9 +/- 0.5 microg/mL (chloroform). Fractionation led to the isolation of phenolic esters and alkylphthalides, especially Z-ligustilide, the main lipophilic compound, which showed strong NQO1 inducing properties (CD = 6.9 +/- 1.9 microM). Transcription of many detoxifying enzymes is regulated through the antioxidant response element (ARE) and its transcription factor Nrf2, which is repressed under basal conditions by Keap1. However, exposure to electrophilic inducers that alkylate Keap1 results in higher concentrations of free Nrf2 and ARE activation. The ARE reporter activity was therefore analyzed in HepG2-ARE-C8 cells after incubation with lipophilic extracts of A. sinensis or ligustilide for 24 h. Under these conditions, both the extract and the ligustilide increased ARE-luciferase reporter activity in a dose-dependent manner. Incubation of ligustilide with GSH and subsequent LC-MS-MS analysis revealed that ligustilide as well as oxidized ligustilide species covalently modified GSH. In addition, using MALDI-TOF mass spectrometry and LC-MS-MS, it was demonstrated that the lipophilic extracts, ligustilide, and monooxygenated ligustilide alkylated important cysteine residues in human Keap1 protein, thus activating Nrf2 and transcription of ARE regulated genes. These observations suggest that A. sinensis dietary supplements standardized to ligustilide have potential as chemopreventive agents through induction of detoxification enzymes. | 18,808,158 |
Metallic cation induced one-dimensional assembly of poly(acrylic acid)-1-dodecanethiol-stabilized gold nanoparticles. | In this work, we report a simple approach for controllable synthesis of one-dimensional (1D) gold nanoparticle (AuNP) assemblies in solution. In the presence of divalent metallic ions, poly(acrylic acid)-1-dodecanethiol-stabilized AuNPs (PAA-DDT@AuNPs) are found to form 1D assemblies in aqueous solution by an ion-templated chelation process; this causes an easily measurable change in the absorption spectrum of the particles. The assemblies are very stable and remain suspended in solution for more than one month without significant aggregation. The morphologies of these 1D assemblies are dependent on the concentration of metallic cations in the solution. While lower concentrations led to the formation of particle dimers, higher concentrations generated long nanoparticle chain networks. In addition, the effect of EDTA, the solution pH, and the size of the PAA-DDT@AuNPs is also studied for further exploration of the mechanism of the formation of the 1D assemblies. | 18,808,165 |
A new similarity found from the correspondence of the critical and Zeno-line parameters. | We find a new similarity based on the relation between the critical and unit compressibility line (Zeno-line) parameters. Our study relies on the fact that the Zeno-line must be tangential to the extension of the binodal liquid branch at the zero temperature domain. We show that this similarity faithfully describes both the numerical simulation data and experimental data for a wide class of real materials (17 gases, water, and 5 metals). Finally we make some predictions for metals which have critical parameters in the phase diagram domain still inaccessible for experiment. | 18,808,178 |
Functionalization of multiwalled carbon nanotubes by pyrene-labeled hydroxypropyl cellulose. | Pyrene-labeled hydroxypropyl cellulose (HPC-Py) was synthesized through a condensation reaction between hydroxypropyl cellulose (HPC) and 1-pyrenebutyric acid (Py). A hybrid (HPC/MWNTs) of the HPC-Py and multiwalled carbon nanotubes (MWNTs) was prepared through a noncovalent method. Temperature-variable UV-vis spectra indicated that the HPC-Py had a lower critical solution temperature of about 44 degrees C in water. (1)H NMR, UV-vis, Raman, and fluorescence spectra were used to systematically investigate the pi-pi stacking interaction between the HPC-Py and MWNTs. Dispersion experiments showed the HPC/MWNTs hybrids could be well dispersed in water and many organic solvents. | 18,808,180 |
Structure and molecular mobility of soy glycinin in the solid state. | We report a multitechnique study of structural organization and molecular mobility for soy glycinin at a low moisture content (<30% w/w) and relate these to its glass-to-rubber transition. Small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy are used to probe structure and mobility on different length and time scales. NMR (approximately 10(-6) to 10(-3) s) reveals transitions at a higher moisture content (>17%) than DSC or SAXS, which sample for much longer times (approximately 10 to 10(3) s) and where changes are detected at >13% water content at 20 degrees C. The mobility transitions are accompanied by small changes in unit-cell parameters and IR band intensities and are associated with the enhanced motion of the polypeptide backbone. This study shows how characteristic features of the ordered regions of the protein (probed by SAXS and FTIR) and mobile segments (probed by NMR and DSC) can be separately monitored and integrated within a mobility transformation framework. | 18,808,181 |
Cotunneling model for current-induced events in molecular wires. | Many phenomena in molecular transport junctions involve transitions between electronic states of the molecular wire, and, therefore, cannot be described adequately using the Landauer picture. We present a model for cotunneling processes in molecular wires. These are coherent second-order processes that can be observed at low temperatures. As an example, we consider the STM-induced dissociation of acetylene. The large voltage threshold for dissociation observed experimentally is naturally accounted for within the cotunneling model. | 18,808,190 |
Managing discrimination in selection: the influence of directives from an authority and social dominance orientation. | The authors examined one manner in which to decrease the negative impact of social dominance orientation (SDO), an individual difference variable that indicates support for the "domination of 'inferior' groups by 'superior' groups" (J. Sidanius & F. Pratto, 1999, p. 48), on the selection of candidates from low-status groups within society. Consistent with the tenets of social dominance theory, in 2 studies we found that those high in SDO reported that they were less likely to select a potential team member who is a member of a low-status group (i.e., a White female in Study 1 and a Black male in Study 2) than those low in SDO. However, explicit directives from an authority moderated this effect such that those high in SDO were more likely to select both candidates when authority figures clearly communicated that job performance indicators should be used when choosing team members. Thus, our studies suggest that the negative effects of SDO may be attenuated if those high in SDO are instructed by superiors to use legitimate performance criteria to evaluate job candidates. | 18,808,220 |
Collaborative coping and daily mood in couples dealing with prostate cancer. | Collaborative coping (i.e., spouses pooling resources and problem solving jointly) may be associated with better daily mood because of heightened perceptions of efficacy in coping with stressful events. The study examined the daily processes of collaborative coping (individuals' perceptions that the spouse collaborated), perceived coping effectiveness (ratings of how well they dealt with the event), and mood (i.e., Positive and Negative Affect Scale) across 14 days in 57 older couples coping with stressors involving the husband's prostate cancer and daily life in general. In hierarchical multivariate linear models, collaborative coping was associated with more positive same-day mood for both husbands and wives and less negative mood for wives only. These associations were partially mediated by heightened perceptions of coping effectiveness. Exploratory analyses revealed that collaborative coping was more frequent among wives who performed more poorly on cognitive tests and couples who reported greater marital satisfaction and more frequently using collaboration to make decisions. The results suggest that older couples may benefit from collaborative coping in dealing with problems surrounding illness. | 18,808,241 |
Oh, honey, I already forgot that: strategic control of directed forgetting in older and younger adults. | Two experiments investigated list-method directed forgetting with older and younger adults. Using standard directed forgetting instructions, significant forgetting was obtained with younger but not older adults. However, in Experiment 1 older adults showed forgetting with an experimenter-provided strategy that induced a mental context change--specifically, engaging in diversionary thought. Experiment 2 showed that age-related differences in directed forgetting occurred because older adults were less likely than younger adults to initiate a strategy to attempt to forget. When the instructions were revised to downplay their concerns about memory, older adults engaged in effective forgetting strategies and showed significant directed forgetting comparable in magnitude to younger adults. The results highlight the importance of strategic processes in directed forgetting. | 18,808,251 |
Not so ugly after all: when shame acts as a commitment device. | Most psychological theories and research on shame focus on the ugly aspects and negative consequences of this emotion. Theories on moral emotions, however, assume that shame acts as a commitment device motivating prosocial behavior. To solve this apparent paradox, the authors studied the effects of shame on prosocial behavior. Shame was hypothesized to motivate prosocial behavior when it was relevant for the decision at hand (endogenous). In contrast, shame that was not relevant for the decision at hand (exogenous) was hypothesized to have no such effects. Four experiments with three different shame inductions and two different measures of prosocial behavior confirmed that endogenous shame motivated prosocial behavior for proselfs but that exogenous shame did not. Shame is shown to have a clear interpersonal function in the sense that it acts as a commitment device. | 18,808,269 |
Mechanisms of muscle degeneration, regeneration, and repair in the muscular dystrophies. | To withstand the rigors of contraction, muscle fibers have specialized protein complexes that buffer against mechanical stress and a multifaceted repair system that is rapidly activated after injury. Genetic studies first identified the mechanosensory signaling network that connects the structural elements of muscle and, more recently, have identified repair elements of muscle. Defects in the genes encoding the components of these systems lead to muscular dystrophy, a family of genetic disorders characterized by progressive muscle wasting. Although the age of onset, affected muscles, and severity vary considerably, all muscular dystrophies are characterized by muscle necrosis that overtakes the regenerative capacity of muscle. The resulting replacement of muscle by fatty and fibrous tissue leaves muscle increasingly weak and nonfunctional. This review discusses the cellular mechanisms that are primarily and secondarily disrupted in muscular dystrophy, focusing on membrane degeneration, muscle regeneration, and the repair of muscle. | 18,808,326 |
Safety and immunogenicity of an inactivated influenza A/H5N1 vaccine given with or without aluminum hydroxide to healthy adults: results of a phase I-II randomized clinical trial. | Dose-sparing strategies are being explored for vaccines against pandemic influenza. We evaluated the dose-sparing potential of aluminum hydroxide (AlOH) adjuvant. A total of 600 healthy subjects (age, 18-49 years) were randomized to receive 2 vaccinations 1 month apart with subvirion inactivated influenza A/H5N1 vaccine containing 7.5, 15, or 45 microg of hemagglutinin (HA), with or without 600 microg of aluminum hydroxide (AlOH), or 3.75 microg of HA, with or without 300 microg of AlOH. Serum specimens were obtained for antibody assays before and 1 month after each vaccination. All formulations were safe. Injection site discomfort was more frequent in groups given vaccines with AlOH. Dose-related increases in antibody responses were noted after both vaccinations (P< .001) geometric mean titers of hemagglutination inhibition antibody in vaccines with and without AlOH, respectively, were 5.4 and 5.4 for subjects who received 3.75 microg of HA, 7.7 and 5.3 for those who received 7.5 microg of HA, 8.1 and 8.5 for those who received 15 microg of HA, and 14.8 and 12 for those who received 45 microg of HA. A > or =4-fold increase in titer was observed in 2% and 2% of subjects who received 3.75 microg of HA with or without AlOH, respectively; in 14% and 0% who received 7 microg of HA; in 14% and 13% who received 15 microg of HA; and in 33% and 25% who received 45 microg of HA. Addition of AlOH enhanced responses only for subjects who received 7.5 microg of HA, but responses in subjects who received 7.5 microg of HA without AlOH were unexpectedly low. Overall, a meaningful beneficial effect of AlOH adjuvant was not observed. ClinicalTrials.gov identifier: NCT00296634 . | 18,808,338 |
Emergence of Clostridium difficile infection due to a new hypervirulent strain, polymerase chain reaction ribotype 078. | Since 2005, an increase in the prevalence of Clostridium difficile infection (CDI) due to polymerase chain reaction ribotype 078 has been noticed in The Netherlands. This strain has also been identified as the predominant strain in pigs and calves. CDI caused by type 078 was studied in relation to CDI caused by the hypervirulent type 027 and by types other than 027 and 078. Human and porcine isolates were further investigated and characterized by multilocus variable number tandem repeat analysis. From February 2005 through February 2008, the incidence of type 078 among isolates obtained from 1687 patients increased from 3% to 13%. Compared with patients infected with type 027, patients infected with type 078 were younger (67.4 vs. 73.5 years; P < .01) and more frequently had community-associated disease (17.5% vs. 6.7%; odds ratio, 2.98; 95% confidence interval, 2.11-8.02); rates of severe diarrhea (38.9% vs. 40.0%) and attributable mortality (3.8% vs. 4.0%) were similar in both groups. Compared with patients infected with other types, patients infected with type 078 more frequently received fluoroquinolone therapy (29.4% vs. 19.8%; odds ratio, 2.17; 95% confidence interval, 1.06-4.44). Type 078 isolates contained genes for toxin A, toxin B, binary toxin, and a 39-base pair deletion in toxin regulator gene (tcdC), as well as a point mutation at position 184, resulting in a stop codon. Multilocus variable number tandem repeat analysis of 54 human and 11 porcine isolates revealed 4 clonal complexes containing both porcine and human isolates. CDI due to type 078 and CDI due to type 027 present with similar severity, but CDI due to type 078 affects a younger population and is more frequently community associated. C. difficile type 078 isolates from humans and pigs are highly genetically related. | 18,808,358 |
Capsular glucan and intracellular glycogen of Mycobacterium tuberculosis: biosynthesis and impact on the persistence in mice. | Mycobacterium tuberculosis and other pathogenic mycobacterial species produce large amounts of a glycogen-like alpha-glucan that represents the major polysaccharide of their outermost capsular layer. To determine the role of the surface-exposed glucan in the physiology and virulence of these bacteria, orthologues of the glg genes involved in the biosynthesis of glycogen in Escherichia coli were identified in M. tuberculosis H37Rv and inactivated by allelic replacement. Biochemical analyses of the mutants and complemented strains indicated that the synthesis of glucan and glycogen involves the alpha-1,4-glucosyltransferases Rv3032 and GlgA (Rv1212c), the ADP-glucose pyrophosphorylase GlgC (Rv1213) and the branching enzyme GlgB (Rv1326c). Disruption of glgC reduced by half the glucan and glycogen contents of M. tuberculosis, whereas the inactivation of glgA and Rv3032 affected the production of capsular glucan and glycogen, respectively. Attempts to disrupt Rv3032 in the glgA mutant were unsuccessful, suggesting that a functional copy of at least one of the two alpha-1,4-glucosyltransferases is required for growth. Importantly, the glgA mutant was impaired in its ability to persist in mice, suggesting a role for the capsular glucan in the persistence phase of infection. Unexpectedly, GlgB was found to be an essential enzyme. | 18,808,383 |
The genome of Rhodobacter sphaeroides strain 2.4.1 encodes functional cobinamide salvaging systems of archaeal and bacterial origins. | Bacteria and archaea use distinct pathways for salvaging exogenous cobinamide (Cbi), a precursor of adenosylcobalamin (coenzyme B(12)). The bacterial pathway depends on a bifunctional enzyme with kinase and guanylyltransferase activities (CobP in aerobic adenosylcobalamin synthesizers) to convert adenosylcobinamide (AdoCbi) to AdoCbi-guanosine diphosphate (AdoCbi-GDP) via an AdoCbi-phosphate intermediate. Archaea lack CobP, and use a different strategy for the synthesis of AdoCbi-GDP. Archaea cleave off the aminopropanol group of AdoCbi using the CbiZ AdoCbi amidohydrolase to generate adenosylcobyric acid, which is converted to AdoCbi-phosphate by the CbiB synthetase, and to AdoCbi-GDP by the CobY guanylyltransferase. We report phylogenetic, in vivo and in vitro evidence that the genome of Rhodobacter sphaeroides encodes functional enzymes for Cbi salvaging systems of both bacterial and archaeal origins. Products of the reactions were identified by high-performance liquid chromatography, UV-visible spectroscopy and bioassay. The cbiZ genes of several bacteria and archaea restored Cbi salvaging in a strain of Salmonella enterica unable to salvage Cbi. Phylogenetic data led us to conclude that CbiZ is an enzyme of archaeal origin that was horizontally transferred to bacteria. Reasons why some bacteria may contain both types of Cbi salvaging systems are discussed. | 18,808,385 |
Risky business: perceived behavior of local scientists and community support for their research. | Attracting new technologies to a region can mean significant economic growth, so understanding why some communities may not favor becoming "the next Silicon Valley" merits consideration. This study investigates the relationship among the perceived behavior of local scientists and community members' attitudes toward their research. Drawing on theories from organizational justice, it hypothesizes that when local residents consider scientists as more just in their behavior, they will also have more favorable attitudes toward the scientists and their research. Just, in this sense, refers to whether scientists are perceived as fair in terms of outcomes, procedures, interpersonal treatment, and explanations in their dealings with the community. Favorable attitudes are measured in terms of concern about new technologies and satisfaction with research. Data were collected via a mail survey of residents in two upstate New York counties (N= 1,306) that host substantial technology research facilities. Controlling for demographics, media use, basic science knowledge, and technology awareness, the results show that distributive justice (i.e., fairness of outcomes) had a consistent, negative relationship with technology concern. In comparison, all four justice variables were positively related with research satisfaction. The findings suggest that the perceived behavior of local scientists may indeed impact community support for their research. | 18,808,391 |
Parameters of a dose-response model are on the boundary: what happens with BMDL? | It is well known that, under appropriate regularity conditions, the asymptotic distribution for the likelihood ratio statistic is chi(2). This result is used in EPA's benchmark dose software to obtain a lower confidence bound (BMDL) for the benchmark dose (BMD) by the profile likelihood method. Recently, based on work by Self and Liang, it has been demonstrated that the asymptotic distribution of the likelihood ratio remains the same if some of the regularity conditions are violated, that is, when true values of some nuisance parameters are on the boundary. That is often the situation for BMD analysis of cancer bioassay data. In this article, we study by simulation the coverage of one- and two-sided confidence intervals for BMD when some of the model parameters have true values on the boundary of a parameter space. Fortunately, because two-sided confidence intervals (size 1-2alpha) have coverage close to the nominal level when there are 50 animals in each group, the coverage of nominal 1-alpha one-sided intervals is bounded between roughly 1-2alpha and 1. In many of the simulation scenarios with a nominal one-sided confidence level of 95%, that is, alpha= 0.05, coverage of the BMDL was close to 1, but for some scenarios coverage was close to 90%, both for a group size of 50 animals and asymptotically (group size 100,000). Another important observation is that when the true parameter is below the boundary, as with the shape parameter of a log-logistic model, the coverage of BMDL in a constrained model (a case of model misspecification not uncommon in BMDS analyses) may be very small and even approach 0 asymptotically. We also discuss that whenever profile likelihood is used for one-sided tests, the Self and Liang methodology is needed to derive the correct asymptotic distribution. | 18,808,395 |
Adjunctive lithium treatment in the prevention of suicidal behaviour in depressive disorders: a randomised, placebo-controlled, 1-year trial. | Evidence based on controlled studies is still limited for treatment strategies that prevent recurrence of suicide attempts. Findings from observational as well as meta-analytic studies strongly suggest that lithium may have suicide-protective properties. Patients with a recent suicide attempt in the context of an affective spectrum disorder (n = 167) were treated with either lithium or placebo during a 12-month period. Survival analysis showed no significant difference of suicidal acts between lithium and placebo-treated individuals (adjusted hazard ratio 0.517; 95% CI 0.18-1.43). However, post hoc analysis revealed that all completed suicides had occurred in the placebo group accounting for a significant difference in incidence rates (P = 0.049). Results indicate that lithium treatment might be effective in reducing the risk of completed suicide in adult patients with affective disorders. Our findings contribute to the growing body of evidence suggesting a specific antisuicidal effect of lithium. | 18,808,400 |
COMT ValMet moderation of cannabis-induced psychosis: a momentary assessment study of 'switching on' hallucinations in the flow of daily life. | A functional polymorphism in the catechol-o-methyltransferase gene (COMT Val(158)Met) may moderate the psychosis-inducing effects of cannabis. In order to extend this finding to dynamic effects in the flow of daily life, a momentary assessment study of psychotic symptoms in response to cannabis use was conducted. The experience sampling technique was used to collect data on cannabis use and occurrence of symptoms in daily life in patients with a psychotic disorder (n = 31) and healthy controls (n = 25). Carriers of the COMT Val(158)Met Val allele, but not subjects with the Met/Met genotype, showed an increase in hallucinations after cannabis exposure, conditional on prior evidence of psychometric psychosis liability. The findings confirm that in people with psychometric evidence of psychosis liability, COMT Val(158)Met genotype moderates the association between cannabis and psychotic phenomena in the flow of daily life. | 18,808,401 |
Does a nerve-sparing technique or potency affect continence after open radical retropubic prostatectomy? | To characterize the effect of preserving the neurovascular bundle (NVB) and of potency on urinary continence after open radical retropubic prostatectomy (ORRP). Between October 2000 to September 2005, 1110 consecutive continent men had ORRP by one surgeon. The University of California Los Angeles Prostate Cancer Index was self-administered at baseline and 3, 6, 12, and 24 months after ORRP. Men were considered continent if they responded that they had total urinary control or had occasional urinary leakage. Men were considered potent if they engaged in sexual intercourse with or without the use of phosphodiesterase inhibitors at least once in the month before or after ORRP. Of the 1110 men, 728 (66%) were potent and continent at baseline. Men undergoing adjuvant hormonal therapy, radiation therapy or chemotherapy were excluded. The potency status was evaluated in 610 men at 24 months after ORRP, and the number of NVBs preserved was recorded at the time of ORRP. Of men who were potent at baseline and had bilateral vs unilateral nerve sparing, 96% and 99% were continent at 24 months, respectively (P = 0.50). Of the men who were potent and impotent at 24 months, 98% and 96% were continent at 24 months, respectively (P = 0.25). Continence did not depend on whether men regained potency or whether they had a bilateral or a unilateral nerve-sparing procedure. Our observation that only 60% of men undergoing bilateral nerve-sparing ORRP regain potency suggests that the NVBs are often inadvertently injured, despite efforts to preserve them. We feel that potency status is the best indicator of the true extent of NVB preservation. That men undergoing bilateral vs unilateral nerve-sparing procedures, and that potent vs impotent men at 24 months have similar continence rates, provides compelling evidence that nerve-sparing is not associated with better continence. Based on these findings, NVBs should not be preserved in men with baseline erectile dysfunction, with the expectation of improving continence. | 18,808,410 |
Incidence of primary cutaneous T-cell lymphoma in Norway. | Studies from different countries have reported an increased incidence of primary cutaneous lymphomas over the last decades. To estimate the incidence rates of primary cutaneous T-cell lymphoma (CTCL) and mycosis fungoides (MF)/Sézary syndrome (SS) in Norway, and to compare these rates with those reported from other countries. Data from the Cancer Registry of Norway on non-Hodgkin lymphomas during the period 1980-2003 were analysed. In total, 337 cases of CTCL were reported to the Cancer Registry during the study period, of which 262 cases were classified as MF/SS. The incidence rate of CTCL increased significantly (P(trend) < 0.001) from 0.16 (95% confidence interval, CI 0.11-0.20) per 100,000 person-years in 1980-84 to 0.29 (95% CI 0.22-0.36) per 100,000 person-years in 2000-2003. The incidence of MF/SS also increased during the same period (P(trend) = 0.05) from 0.15 (95% CI 0.10-0.19) per 100,000 person-years to 0.18 (95% CI 0.13-0.24) per 100,000 person-years. The incidence of both CTCL and MF/SS increased in Norway during the period 1980-2003. | 18,808,419 |
Levetiracetam in absence epilepsy. | The aim of the study was to assess the efficacy, tolerability, and safety of levetiracetam therapy in children and adolescents with absence epilepsy. Twenty-one participants (11 male, 10 female) with typical absence seizures were enrolled in this prospective study from seven centres in Italy. The mean age and age range at time of enrollment into the study were 8 years 9 months (SD 0.9) and 5 years 1 month to 13 years respectively. All patients were carefully evaluated at 6 months from baseline, and 12 patients were also re-evaluated at 12 months after the beginning of therapy with levetiracetam. At the 6-month evaluation, out of 21 patients studied, 11 were seizure free and one showed 'decreased' seizures (more than 50% reduction in seizures). A less than 50% reduction in seizures was observed in nine patients. At the 12-month evaluation, 10 patients were completely seizure free and two were seizure free with some anomalies in electroencephalograms. Two patients who had shown no improvement at 6 months had decreased seizures at the second follow-up. Our results suggest that monotherapy with levetiracetam could be effective and well tolerated in patients with childhood absence epilepsy and juvenile absence epilepsy. Prospective, large, long-term double-blind studies are needed to confirm these findings. | 18,808,424 |
Mechanisms of Zn2+ efflux in cultured cortical neurons. | Zinc dyshomeostasis in brain might be involved in the pathogenesis of brain diseases such as Alzheimer's disease and stroke. Resting neurons tightly regulate and maintain low to subnanomolar levels of intracellular free Zn2+, but mechanisms of normal Zn2+ homeostasis are poorly understood. In this study, the mechanisms of transporter-mediated Zn2+extrusion across the plasma membrane of cultured cortical neurons were studied. Changes in intracellular free Zn2+ levels were tracked in individual neurons by microfluorometry using a Zn2+ selective fluorophore, FluoZin3. Unopposed Zn2+efflux was measured by first loading cultured cortical neurons with Zn2+ then reducing extracellular Zn2+ to near zero by addition of EDTA. Studies revealed that the primary means of Zn2+ efflux in cortical neurons required both extracellular Na+ and Ca2+. The actions of either Na+ or Ca2+ on Zn2+ efflux were blunted in the absence of the other cation. Reversed Na+ gradients could induce Zn2+ uptake. The Na+ dependence of Zn2+ efflux was not affected by a small pHo shift (7.6-8);whereas an effect of Ca2+ was not observed at pHo 8. In summary, a Na+, Ca2+/Zn2+ exchanger mechanism is proposed to be the primary transport mechanism that extrudes Zn2+ when neuronal intracellular free Zn2+ levels rise. | 18,808,447 |
Type-B monogalactosyldiacylglycerol synthases are involved in phosphate starvation-induced lipid remodeling, and are crucial for low-phosphate adaptation. | Mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively) constitute the bulk of membrane lipids in plant chloroplasts. Mutant analyses in Arabidopsis have shown that these galactolipids are essential for chloroplast biogenesis and photoautotrophic growth. Moreover, these non-phosphorous lipids are proposed to participate in low-phosphate (Pi) adaptations. Under Pi-limited conditions, a drastic accumulation of DGDG occurs concomitantly with a large reduction in membrane phospholipids, suggesting that plants substitute DGDG for phospholipids during Pi starvation. Previously, we reported that among the three MGDG synthase genes (MGD1, MGD2 and MGD3), the type-B MGD2 and MGD3 are upregulated in parallel with DGDG synthase genes during Pi starvation. Here, we describe the identification and characterization of T-DNA insertional mutants of Arabidopsis type-B MGD genes. Under Pi-starved conditions, the mgd3-1 mutant showed a drastic reduction in DGDG accumulation, particularly in the root, indicating that MGD3 is the main isoform responsible for DGDG biosynthesis in Pi-starved roots. Moreover, in the roots of mgd2 mgd3 plants, Pi stress-induced accumulation of DGDG was almost fully abolished, showing that type-B MGD enzymes are essential for membrane lipid remodeling in Pi-starved roots. Reductions in fresh weight, root growth and photosynthetic performance were also observed in these mutants under Pi-starved conditions. These results demonstrate that Pi stress-induced membrane lipid remodeling is important in plant growth during Pi starvation. The widespread distribution of type-B MGD genes in land plants suggests that membrane lipid remodeling mediated by type-B MGD enzymes is a potent adaptation to Pi deficiency for land plants. | 18,808,455 |
An N-terminal diacidic motif is required for the trafficking of maize aquaporins ZmPIP2;4 and ZmPIP2;5 to the plasma membrane. | Maize plasma membrane aquaporins (ZmPIPs, where PIP is the plasma membrane intrinsic protein) fall into two groups, ZmPIP1s and ZmPIP2s, which, when expressed alone in mesophyll protoplasts, are found in different subcellular locations. Whereas ZmPIP1s are retained in the endoplasmic reticulum (ER), ZmPIP2s are found in the plasma membrane (PM). We previously showed that, when co-expressed with ZmPIP2s, ZmPIP1s are relocalized to the PM, and that this relocalization results from the formation of hetero-oligomers between ZmPIP1s and ZmPIP2s. To determine the domains responsible for the ER retention and PM localization, respectively, of ZmPIP1s and ZmPIP2s, truncated and mutated ZmPIPs were generated, together with chimeric proteins created by swapping the N- or C-terminal regions of ZmPIP2s and ZmPIP1s. These mutated proteins were fused to the mYFP and/or mCFP, and the fusion proteins were expressed in maize mesophyll protoplasts, and were then localized by microscopy. This allowed us to identify a diacidic motif, DIE (Asp-Ile-Glu), at position 4-6 of the N-terminus of ZmPIP2;5, that is essential for ER export. This motif was conserved and functional in ZmPIP2;4, but was absent in ZmPIP2;1. In addition, we showed that the N-terminus of ZmPIP2;5 was not sufficient to cause the export of ZmPIP1;2 from the ER. A study of ZmPIP1;2 mutants suggested that the N- and C-termini of this protein are probably not involved in ER retention. Together, these results show that the trafficking of maize PM aquaporins is differentially regulated depending on the isoform, and involves a specific signal and mechanism. | 18,808,456 |
Violence and drug use in rural teens: national prevalence estimates from the 2003 Youth Risk Behavior Survey. | The purpose of this study was to compare national estimates of drug use and exposure to violence between rural and urban teens. Twenty-eight dependent variables from the 2003 Youth Risk Behavior Survey were used to compare violent activities, victimization, suicidal behavior, tobacco use, alcohol use, and illegal drug use across rural, urban, and suburban teens across the country. Overall, rural teens were equally or more likely than both suburban and urban teens to report experiencing many measures of violent behavior, victimization, suicide behaviors, and drug use. Among all teens, nonwhites reported equal or higher rates of violent behavior and victimization than whites, but these associations disappeared within the rural-only population. Rural areas do not appear to provide a strongly protective effect against risk behaviors in teens and may be a risk factor in itself. Community prevention efforts should focus on reaching rural areas and segmenting program content based on need. Where white teens might benefit from an emphasis on preventing tobacco and alcohol use, nonwhite teens would benefit from an emphasis on preventing violence and victimization. | 18,808,475 |
Acute migraine medications and evolution from episodic to chronic migraine: a longitudinal population-based study. | Though symptomatic medication overuse is believed to play a major role in progression from episodic to chronic or transformed migraine (TM), population-based longitudinal data on these agents are limited. To assess the role of specific classes of acute medications in the development of TM in episodic migraine (EM) sufferers after adjusting for other risk factors for headache progression. As a part of the American Migraine Prevalence and Prevention study (AMPP), we initially surveyed a population sample of 120,000 individuals to identify a sample of migraineurs to be followed annually over 5 years. Using logistic and linear regression, we modeled the probability of transition from EM in 2005 to TM in 2006 in relation to medication use status at baseline. Adjustments were made for gender, headache frequency and severity, and prevention medication use. Of 8219 individuals with EM in 2005, 209 (2.5%) had developed TM by 2006. Baseline headache frequency was a risk factor for TM. Using acetaminophen user as the reference group, individuals who used medications containing barbiturates (OR = 2.06, 95%CI = 1.3-3.1) or opiates (OR = 1.98, 95%CI = 1.4-2.2) were at increased risk of TM. A dose-response relationship was found for use of barbiturates. Use of triptans (OR = 1.25, 95%CI = 0.9-1.7) at baseline was not associated with prospective risk of TM. Overall, NSAIDs (OR = 0.85, 95%CI = 0.63-1.17) were not associated with TM. Indeed, NSAIDs were protective against transition to TM at low to moderate monthly headache days, but were associated with increased risk of transition to TM at high levels of monthly headache days. EM sufferers develop TM at the rate of 2.5% per year. Any use of barbiturates and opiates was associated with increased risk of TM after adjusting for covariates, while triptans were not. NSAIDs were protective or inducers depending on the headache frequency. | 18,808,500 |
Cellular expression of Bcl-2 and Bax in atrophic submandibular glands of rats. | In submandibular gland atrophy, most acinar cells disappear by apoptosis, while many duct cells remain. The present study aimed to establish whether Bcl-2 and Bax, members of the Bcl-2 gene family, regulating the signalling pathway of apoptosis were involved in duct cell survival and acinar cell death in atrophic submandibular glands. The excretory duct of rat submandibular gland was doubly ligated with metal clips from 1 to 14 days to induce atrophy to the gland. The expressions of Bcl-2 and Bax in the atrophic submandibular gland were examined using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). Immunohistochemically, Bcl-2 expression was identified in duct cells in the experimental glands at all time points. Some acinar cells showed Bax positivity 1 day after excretory duct ligation, and there were more Bax-positive acinar cells on days 3 and 5 when many apoptotic acinar cells were observed. Analysis by RT-PCR showed that the expression of mRNA for Bcl-2 became stronger as the glandular atrophy progressed and that Bax mRNA strongly expressed on days 1 and 3. These observations suggest that Bcl-2 inhibits duct cell apoptosis and Bax promotes apoptosis of acinar cells during atrophy of submandibular glands. | 18,808,524 |
Informed consent and medical ordeal: a qualitative study. | Informed consent is a mainstay of clinical practice, with both moral and legal forces. Material disclosure about extreme treatments, however, is unlikely to convey the full impact of the experience of treatment. Informed consent may be flawed under such circumstances. The aims of this study were to compare expressed satisfaction with pretreatment information to satisfaction after experiencing autologous stem cell transplantation for recurrent lymphoma. A qualitative, narrative-based cohort study was conducted in a bone-marrow transplant unit of a teaching hospital at Westmead Hospital, Sydney, Australia. The cohort consisted of 10 transplant recipients and 9 of their nominated lay carers. The outcome measure was satisfaction expressed in narrative interviews at the time of transplantation and 3 months later. We used discourse-analytic techniques to examine the narratives. Both patients and carers expressed high satisfaction with the information given by individual clinicians and by speakers at a formal Information Day held before transplantation. At the first interview, neither patients nor carers commented much on the forthcoming ordeal of chemotherapy and bone marrow ablation, although all patients had undergone previous chemotherapy. At the second interview, the ordeal dominated the narratives and retrospective dissatisfaction with information was common. This study suggests that information about treatment theories and protocols can be satisfactorily communicated, but personal experience of suffering defies communication. This finding has serious implications for the practices involved in obtaining informed consent and for the very notion of informed consent. | 18,808,560 |
Self-reported competence of home nursing staff in Finland. | This paper is a report of a study to investigate the self-reported competence of home nursing staff and whether this is associated with their education, job descriptions, access to help and support and with factors in their psychosocial work environment, such as opportunities for personal growth and development at work. Home nursing staff face increasing demands on their competence. Advances in information technology and working methods have increased the need for education. Thus, information on the factors associated with the competence of home nursing staff help us to support them in a way that improves the quality of care. The data were gathered via a questionnaire completed in 2003 by the home nursing staff of 24 municipalities in different regions of Finland. A total of 2366 home care staff (response rate 63%), of whom 790 were home nursing staff (response rate 65%), were sent questionnaires. Univariate and multivariate logistic regression were used as main statistical methods. The best predictors for self-reported competence of home nursing staff were their reading scientific or professional journals, opportunities for skill development, decision-making latitude and work demands. Simple and practical ways for updating the competence of home nursing staff should be created. These staff are a very important source of information for home care clients. Supporting the knowledge of home nursing staff is also an efficient way of keeping clients and their informal caregivers informed about care guidelines, health and social services and social benefits. | 18,808,590 |
Renal net acid excretion capacity is comparable in prepubescence, adolescence, and young adulthood but falls with aging. | To evaluate whether renal net acid excretion capacity (NAEC) varies across different age groups and, specifically, whether it falls in elderly people. Cross-sectional observational study. Community-based. Young participants were from the DOrtmund Nutritional and Anthropometric Longitudinally Designed Study, Dortmund, Germany; elderly participants were from Gothenburg, Sweden. Twenty-four-hour urine pH, net acid excretion (NAE), urinary phosphorus, total nitrogen excretion, and anthropometric data were measured in healthy elderly people (aged 55-75; n=85), young adults (aged 18-22; n=117), adolescents (aged 13-14; n=112), and prepubescent children (aged 6-7; n=217). NAEC was determined as 24-hour NAE adjusted for urine pH using the residual method. In elderly participants 24-hour urinary pH (5.9+/-0.53) was lower (P<.05) and NAE (60+/-27 mEq/d) higher (P<.05) than in the three other groups. In a regression model adjusted for age, sex, and body surface area, NAEC showed a clear decrease with age, with highest values in prepubescents and lowest in elderly participants. However, NAEC remained significantly lower only in elderly participants (P<.001) after the inclusion of total nitrogen excretion, a protein intake index, which was included because protein intake is known to modulate renal function. NAEC was approximately 8 mEq/d lower in healthy elderly participants than in young adults. The capacity to excrete net endogenous acid does not vary markedly from childhood to young adulthood but falls significantly with age, implying that elderly people may require higher daily alkalizing mineral intake to compensate for renal function losses. | 18,808,599 |
A traditional Chinese herbal medicine used to treat dysmenorrhoea among Taiwanese women. | The purposes of this study were twofold, firstly to ascertain the relative effectiveness of the alternative drug, Si-Wu-Tang (SWT), for dysmenorrhoea treatment and secondly to compare two different timings for consumption of SWT in terms of menstrual pain. A two-group time series experimental design. A total of 49 participants were alternately assigned into two study groups. The experimental group was provided with 15 g of SWT daily for seven consecutive days, subsequent to the cessation of menstrual bleeding, for two consecutive menstrual cycles and the comparison group was provided with a similar intervention as soon as menstrual bleeding was noted. The degree of menstrual pain was recorded daily using a visual analogue scale and the duration of pain was also recorded during menstrual bleeding for five consecutive menstrual cycles. The results indicated that the decrease in menstrual pain levels and the duration of pain between the experimental group and the comparison group was not significant. However, the decrease in menstrual pain over the five menstrual cycles within the experimental group (from 2.07 to 1.42; 2.71 to 1.21; p < 0.05) and within the comparison group (from 1.94 to 1.23; 2.66 to 1.68; p < 0.05) were significant. The SWT formula has been continuously standardised for effective use as part of menstrual health and can be integrated as an alternative therapy within Western medicine. This study provides information for health care professionals not only about the general principles of traditional Chinese medicine, but also about the selection and consumption of an appropriate SWT formula among Asian women with dysmenorrhoea. Moreover, nurses should build up a partnership with their clients of Asian origins based on the use of an alternative therapy using different assessment criteria that are related to healing and recovery based on bodily constitution balance. | 18,808,624 |
Magnetic resonance imaging traits in siblings discordant for Alzheimer disease. | Magnetic resonance imaging (MRI) can aid clinical assessment of brain changes potentially correlated with Alzheimer disease (AD). MRI traits may improve our ability to identify genes associated with AD-outcomes. We evaluated semi-quantitative MRI measures as endophenotypes for genetic studies by assessing their association with AD in families from the Multi-Institutional Research in Alzheimer Genetic Epidemiology (MIRAGE) Study. Discordant siblings from multiple ethnicities were ascertained through a single affected proband. Semi-quantitative MRI measures were obtained for each individual. The association between continuous/ordinal MRI traits and AD were analyzed using generalized estimating equations. Medical history and Apolipoprotein E (APOE)epsilon4 status were evaluated as potential confounders. Comparisons of 214 affected and 234 unaffected subjects from 229 sibships revealed that general cerebral atrophy, white matter hyperintensities (WMH), and mediotemporal atrophy differed significantly between groups (each at P < .0001) and varied by ethnicity. Age at MRI and duration of AD confounded all associations between AD and MRI traits. Among unaffected sibs, the presence of at least one APOEepsilon4 allele and MRI infarction was associated with more WMH after adjusting for age at MRI. The strong association between MRI traits and AD suggests that MRI traits may be informative endophenotypes for basic and clinical studies of AD. In particular, WMH may be a marker of vascular disease that contributes to AD pathogenesis. | 18,808,654 |
Generation of diverse neuronal subtypes in cloned populations of stem-like cells. | The central nervous tissue contains diverse subtypes of neurons with characteristic morphological and physiological features and different neurotransmitter phenotypes. The generation of neurons with defined neurotransmitter phenotypes seems to be governed by factors differently expressed along the anterior-posterior and dorsal-ventral body axes. The mechanisms of the cell-type determination, however, are poorly understood. Selected neuronal phenotypes had been generated from embryonic stem (ES) cells, but similar results were not obtained on more restricted neural stem cells, presumably due to the lack of homogeneous neural stem cell populations as a starting material. In the presented work, the establishment of different neurotransmitter phenotypes was investigated in the course of in vitro induced neural differentiation of a one-cell derived neuroectodermal cell line, in conjunction with the activation of various region-specific genes. For comparison, similar studies were carried out on the R1 embryonic stem (ES) and P19 multipotent embryonic carcinoma (EC) cells. In response to a short treatment with all-trans retinoic acid, all cell lines gave rise to neurons and astrocytes. Non-induced neural stem cells and self-renewing cells persisting in differentiated cultures, expressed "stemness genes" along with early embryonic anterior-dorsal positional genes, but did not express the investigated CNS region-specific genes. In differentiating stem-like cell populations, on the other hand, different region-specific genes, those expressed in non-overlapping regions along the body axes were activated. The potential for diverse regional specifications was induced in parallel with the initiation of neural tissue-type differentiation. In accordance with the wide regional specification potential, neurons with different neurotransmitter phenotypes developed. Mechanisms inherent to one-cell derived neural stem cell populations were sufficient to establish glutamatergic and GABAergic neuronal phenotypes but failed to manifest cathecolaminergic neurons. The data indicate that genes involved in positional determination are activated along with pro-neuronal genes in conditions excluding any outside influences. Interactions among progenies of one cell derived neural stem cells are sufficient for the activation of diverse region specific genes and initiate different routes of neuronal specification. | 18,808,670 |
pi-Turns: types, systematics and the context of their occurrence in protein structures. | For a proper understanding of protein structure and folding it is important to know if a polypeptide segment adopts a conformation inherent in the sequence or it depends on the context of its flanking secondary structures. Turns of various lengths have been studied and characterized starting from three-residue gamma-turn to six-residue pi-turn. The Schellman motif occurring at the C-terminal end of alpha-helices is a classical example of hydrogen bonded pi-turn involving residues at (i) and (i+5) positions. Hydrogen bonded and non-hydrogen bonded beta- and alpha-turns have been identified previously; likewise, a systematic characterization of pi-turns would provide valuable insight into turn structures. An analysis of protein structures indicates that at least 20% of pi-turns occur independent of the Schellman motif. The two categories of pi-turns, designated as pi-HB and SCH, have been further classified on the basis of backbone conformation and both have AAAa as the major class. They differ in the residue usage at position (i+1), the former having a large preference for Pro that is absent in the latter. As in the case of shorter length beta- and alpha-turns, pi-turns have also been identified not only on the basis of the existence of hydrogen bond, but also using the distance between terminal C alpha-atoms, and this resulted in a comparable number of non-hydrogen-bonded pi-turns (pi-NHB). The presence of shorter beta- and alpha-turns within all categories of pi-turns, the subtle variations in backbone torsion angles along the turn residues, the location of the turns in the context of tertiary structures have been studied. pi-turns have been characterized, first using hydrogen bond and the distance between C alpha atoms of the terminal residues, and then using backbone torsion angles. While the Schellman motif has a structural role in helix termination, many of the pi-HB turns, being located on surface cavities, have functional role and there is also sequence conservation. | 18,808,671 |
Model-driven analysis of experimentally determined growth phenotypes for 465 yeast gene deletion mutants under 16 different conditions. | Understanding the response of complex biochemical networks to genetic perturbations and environmental variability is a fundamental challenge in biology. Integration of high-throughput experimental assays and genome-scale computational methods is likely to produce insight otherwise unreachable, but specific examples of such integration have only begun to be explored. In this study, we measured growth phenotypes of 465 Saccharomyces cerevisiae gene deletion mutants under 16 metabolically relevant conditions and integrated them with the corresponding flux balance model predictions. We first used discordance between experimental results and model predictions to guide a stage of experimental refinement, which resulted in a significant improvement in the quality of the experimental data. Next, we used discordance still present in the refined experimental data to assess the reliability of yeast metabolism models under different conditions. In addition to estimating predictive capacity based on growth phenotypes, we sought to explain these discordances by examining predicted flux distributions visualized through a new, freely available platform. This analysis led to insight into the glycerol utilization pathway and the potential effects of metabolic shortcuts on model results. Finally, we used model predictions and experimental data to discriminate between alternative raffinose catabolism routes. Our study demonstrates how a new level of integration between high throughput measurements and flux balance model predictions can improve understanding of both experimental and computational results. The added value of a joint analysis is a more reliable platform for specific testing of biological hypotheses, such as the catabolic routes of different carbon sources. | 18,808,699 |
Role of sphingosine 1-phosphate receptor expression in eosinophils of patients with allergic rhinitis, and effect of topical nasal steroid treatment on this receptor expression. | Recent research has indicated that sphingosine 1-phosphate plays a role in allergy. This study examined the effect of allergen challenge on the expression of sphingosine 1-phosphate receptors on the eosinophils of allergic rhinitis patients, and the effect of steroid treatment on this expression. A prospective, non-randomised study. The study had three parts. Firstly, sphingosine 1-phosphate receptor expression on the eosinophils of allergic rhinitis patients and control patients was determined. Secondly, sphingosine 1-phosphate receptor expression was quantified pre- and post-allergen challenge, before and after a short course of fluticasone propionate; all patients underwent symptom scoring and peak nasal inspiratory flow measurement pre- and post-allergen challenge, both before and after steroid or saline treatment. Thirdly, the effect of sphingosine 1-phosphate on eosinophil migration was examined. The eosinophils of both allergic rhinitis patients and controls expressed sphingosine 1-phosphate1, 3, 4, and 5. Eosinophils from all allergic rhinitis patients demonstrated up-regulation in sphingosine 1-phosphate expression after allergen challenge. These changes were statistically very significant for sphingosine 1-phosphate1, 4, and 5, and moderately significant for sphingosine 1-phosphate3. Sphingosine 1-phosphate receptor expression up-regulation was abolished in the steroid-treated group after allergen challenge; however, the saline-treated group showed no change in sphingosine 1-phosphate receptor expression after allergen challenge. Peak nasal inspiratory flow scores were significantly diminished after allergen challenge prior to treatment, but not after a course of topical nasal steroids. Sphingosine 1-phosphate induced eosinophil chemotaxis was increased following allergen challenge in allergic rhinitis subjects. Local intranasal steroid therapy acts directly to block allergen-induced up-regulation of sphingosine 1-phosphate receptors on the peripheral eosinophils of allergic rhinitis patients, and this is coincident with post-challenge peak nasal inspiratory flow measurement improvements. These observations support the idea that such an increase in sphingosine 1-phosphate receptor expression is clinically relevant in allergic rhinitis, with potential consequences for eosinophil migration and survival. | 18,808,729 |
Physician, affective, and cognitive variables differentially predict 'initiation' versus 'maintenance' PSA screening profiles in diverse groups of men. | To evaluate the relevance of demographic, physician, and psychological characteristics to PSA screening in ethnic subpopulations and ascertain whether the same characteristics distinguish men who have never had a PSA from those who screen infrequently and those who screen yearly (adhere). Stratified cluster-sampling was used to recruit 533 men (45-70 years) from four ethnic groups: African-American; European-American; immigrant Jamaican; and immigrant men from Trinidad and Tobago. Men provided demographic and structural (insurance, regular physician, annual exam, and physician recommendation), cognitive (risk and efficacy perceptions, knowledge), and emotional variables (cancer worry and embarrassment), and reported on PSA screening history. Multinomial logistic regression used these variables to predict three screening classifications (never screened, partially adherent, and adherent). Multinomial logistic regression showed that minority men were less likely to report either never screening or yearly screening, while younger men were more likely. Lack of a regular physician (OR=2.87, 95% CI 1.39-5.84), an annual exam (OR=1.73, 95% CI 0.91-3.28), and low recommendation (OR=3.76, 95% CI 2.13-6.66) were associated with being categorized as a never (vs. partially adherent) screener, but only annual exam (OR=0.26, 95% CI 0.10-0.63) was associated with yearly screening. Lower cancer worry was marginally associated with never screening (OR=0.59, 95% CI 0.38-1.04), while knowledge was associated with screening yearly over time (OR=0.46, 95% CI 0.28-0.77). Demographic, physician, and psychological variables are differentially associated with never, less than yearly, and yearly screening classifications. Minority men were unlikely to have never screened, but were also less likely to screen yearly. Physician variables were associated with the difference between not screening and partially adherent, but not between partially adherent and yearly screening suggesting that the role of physicians in PSA behaviour over time would benefit from further study. | 18,808,732 |
In vitro evaluation of the cytotoxicity and genotoxicity of resorcylidene aminoguanidine in human diploid cells B-HNF-1. | RAG belongs to appropriate inhibitors of protein glycation, i.e. formation of advanced glycation end products, which are thought to be responsible for some complications of DM, including neuropathy, angiopathy, retinopathy and nephropathy. In the present study authors have evaluated the genotoxic effect of RAG on the cell culture of human neonatal fibroblasts (B-HNF-1) in regard to its potential clinical application as inhibitor of advanced glycation end products in relationships to the pathogenesis of chronic diabetic complications. The direct contact cytotoxicity assay and micronucleus test were performed. The results showed that RAG in the concentration range of 1 x 10-4 to 1 x 10-6 mol.l-1 did not induce any changes in the morphology of exposed B-HNF-1 cells. The frequency of micronuclei was not significantly increased as well. The inhibitive effect of resorcylidene aminoguanidine was directly proportional to its concentration. It can be concluded that RAG at the selected concentrations has an inhibitive effect on proliferation of the treated cells and, at the same time, does not display any genotoxic effects on B-HNF-1 cells. | 18,808,735 |
[The immune system and the eye]. | The special relationship between the eye and the immune system rests on a number of anatomical, physiological and immunological mechanisms. These mechanisms prevent the delicate structures of the eye from potentially damaging immunogenic inflammation while protecting against pathogens. Rather than inflammation, antigen induces a form of systemic and antigen-specific immunological tolerance. Owing to its systemic nature, this tolerance may be utilised to achieve successful treatment of immunological disorders. | 18,808,747 |
[Tumour stem cells in glioma--tomorrow's therapeutic target?]. | Despite intensive research, gliomas still lead to death in most cases. The isolation of brain tumour stem cells from gliomas has paved the way for a growing body of evidence suggesting that these cells are responsible for the resistance of gliomas towards conventional therapy. Recent results suggest that the growth of brain tumours can be inhibited by treatment strategies targeting the brain tumour stem cells. Here, the brain tumour stem cell paradigm is described with a focus on tumour stem cell characteristics and the role of this subpopulation of tumour cells in the resistance towards radiation and chemotherapy. | 18,808,750 |
[Ocular disturbances in neuromuscular disorders]. | Compared with other skeletal muscles, extraocular muscles have fundamentally distinct properties that make them selectively vulnerable to certain neuromuscular disorders. When the oculomotor signs are predominant, their temporal progression allows the clinician to make the distinction between a muscular disease (mitochondrial disorder, oculopharyngeal muscular dystrophy...) and a disorder of the neuromuscular junction (myasthenia gravis, botulism...). In other instances, such as myotonic dystrophy or facioscapulohumeral dystrophy, the ocular signs are not in the forefront but must be recognized by the ophthalmologist as hallmarks of a muscular disorder. In all cases, the collaboration between the neurologist and the ophthalmologist is fruitful. | 18,808,764 |
[Polyradiculopathy revealing an enteropathy associated T-cell lymphoma in a patient with celiac disease]. | Celiac disease (CD) may be complicated by an enteropathy associated T-cell lymphoma (EATL), but lymphomatous dissemination outside the gastrointestinal tract is uncommon especially to the peripheral nervous sytem. We report a 54-year-old CD patient with EATL revealed by subacute polyradiculopathy. Peripheral neuropathies associated with CD are generally not polyradiculopathies, but sensorimotor neuropathies. Peripheral neurological complications of non-Hodgkin lymphoma are more frequent with B-lymphoma and a neurological presentation of EATL is very rare. This case illustrates the usefulness of searching for EATL in CD patients with polyradiculopathy. | 18,808,770 |
The survival impact of the choice of surgical procedure after ipsilateral breast cancer recurrence. | Many women with breast cancer recurrence previously treated with breast-conservation therapy desire repeat lumpectomies. We hypothesized that women undergoing mastectomy for breast cancer recurrence would show superior survival. Patients who previously received breast-conservation therapy diagnosed with an ipsilateral breast cancer recurrence between 1988 and 2004 were identified using the Surveillance, Epidemiology, and End Results database. Univariate survival analysis was performed using the Kaplan-Meier method. Cox regression was used for multivariate analysis. Criteria for analysis were met in 747 patients. Of those, 24% underwent lumpectomy. On univariate analysis, patients undergoing lumpectomy had worse overall survival (P = .03). Five-year survival was 67% versus 78% for the lumpectomy and mastectomy groups, respectively. On multivariate analysis, mastectomy remained significantly associated with better survival with a hazard ratio of .5 (P = .003). The use of lumpectomy for ipsilateral breast cancer recurrence previously treated with breast-conservation therapy should generally be discouraged. | 18,809,050 |
Immediate latissimus dorsi miniflap volume replacement for partial mastectomy: use of intra-operative frozen sections to confirm negative margins. | Latissimus dorsi (LD) miniflap volume replacement is used for immediate reconstruction after partial mastectomy. This prospectively collected series was analyzed to evaluate the accuracy of intraoperative frozen sections. After partial mastectomy, "bed biopsies" were submitted for intraoperative frozen-section analysis. If disease free, volume replacement was undertaken; if involved, targeted re-excisions were taken. Demographic, pathological, and outcome data were recorded. The proportion of breast excised was calculated. Local recurrences were recorded. One hundred ten partial mastectomies with LD miniflap volume replacement were completed. The median proportion of breast excised was 28% (maximum 72%); median weight 207 g. Frozen sections were positive in 33% of patients with a sensitivity of 83% and accuracy of 96% when compared with paraffin sections. Local recurrence occurred in one case. The median follow-up was 41.4 months. LD miniflap volume replacement extends the role of breast-conserving surgery. Frozen-section analysis of bed biopsies facilitates a single-stage procedure. | 18,809,053 |
Optimal treatment of multiple ipsilateral primary breast cancers. | The success of breast-conservation therapy (BCT) for patients with multiple ipsilateral invasive breast cancers (MIBC) is sparsely documented. A retrospective review of single-institution experience. Patients with 2 or more invasive cancers separated by normal breast tissue were included; patients with 1 invasive cancer with additional in situ lesions and those receiving neoadjuvant therapy were excluded. One hundred forty-nine patients were treated over 19 years. Fifty-eight (39%) patients underwent BCT. Preoperatively, multiple tumors were suspected in more mastectomy patients than BCT patients (75% versus 62%). Most patients had 2 tumors and 1 histology. Fifty-five percent of patients with tumors within 1 quadrant underwent BCT versus 10% of patients with tumors in more than 1 quadrant. One hundred eight patients underwent sentinel lymph node (SLN) biopsy. Twenty-seven percent (34) were SLN positive. There were no regional recurrences among the SLN-negative patients. Six patients recurred: 1 nodal, 1 local, and 4 distant. The locoregional BCT recurrence rate was 3.4%. MIBC patients can safely undergo BCT with low recurrence risk. SLNB can be performed with minimal risk of regional recurrence. | 18,809,057 |
Nipple-sparing mastectomy--initial experience at a tertiary center. | Nipple-sparing mastectomy (NSM) combines skin-sparing mastectomy with preservation of the nipple-areolar dermis and intraoperative pathologic assessment of the nipple core. We evaluated our initial experience with NSM in terms of clinical outcomes. An Institutional Review Board-approved retrospective review of patients undergoing NSM between November 2005 and June 2007 was performed. Eighteen NSM and two areola-sparing mastectomies were performed. Indications for surgery were invasive cancer (n = 4), ductal carcinoma in situ (DCIS) (n = 5), pseudoangiomatous stromal hyperplasia (n = 3), and risk reduction (n = 8). The average distance of tumor from the nipple on imaging was 4.8 cm (range 4 to 5.7). Nipple cores were all benign, and 2 patients developed self-limited superficial desquamation of the nipple. At a mean follow up of 10.8 months, all nipple-areolar complexes were intact, and there were no local or systemic recurrences. NSM can be successfully achieved with low morbidity in appropriately selected patients. | 18,809,066 |
Epidemiology of anemia in older adults. | Anemia is a common, multifactorial condition among older adults. The World Health Organization (WHO) definition of anemia (hemoglobin concentration <12 g/dL in women and <13 g/dL in men) is most often used in epidemiologic studies of older adults. More than 10% of community-dwelling adults age 65 years and older has WHO-defined anemia. After age 50 years, prevalence of anemia increases with advancing age and exceeds 20% in those 85 years and older. In nursing homes, anemia is present in 48% to 63% of residents. Incidence of anemia in older adults is not well characterized. Among older adults with anemia, approximately one third have evidence of iron, folate, and/or vitamin B(12) deficiency, another third have renal insufficiency and/or chronic inflammation, and the remaining third have anemia that is unexplained. Several studies demonstrate that anemia is associated with poorer survival in older adults. This review details the distribution and consequences of anemia in older adults and identifies future epidemiologic research needs. | 18,809,090 |
Renal disease and anemia in the elderly. | As individuals age, the incidence of both renal insufficiency and anemia increases. Some of the changes in renal function can be traced to age-related alterations in the renal vasculature that may dissociate renal blood flow from glomerular filtration. In addition, there appear to be paradoxical changes in renal production of erythropoietin (Epo), in that Epo levels actually increase over time with aging, suggesting that the erythroid marrow may become less sensitive to Epo stimulation. These factors, together with the confounding effects of possible nutritional deficits and the disproportionate effect of early-stage diabetes mellitus on renal endocrine function and Epo production, all can contribute to anemia in the elderly. As anemia is an independent predictor of poor outcomes with many diseases and at any age, recognizing and correcting the underlying cause of the anemia is an important aspect of medically managing the elderly patient. | 18,809,093 |
Associations between psychiatric disorders and menstrual cycle characteristics. | An understanding of the relationship between psychiatric disorders and menstrual characteristics is important to the assessment and care of women. Menstrual cycle regularity and length have significant associations with specific current and lifetime psychiatric disorders. The purpose of this study was to investigate whether psychiatric disorders are associated with menstrual cycle length or regularity. The sample included 628 pregnant Medicaid-eligible women from Women, Infants, and Children's Supplemental Nutrition Program sites in five counties in rural Missouri and the city of St. Louis. Women were assessed for current (12-month) and lifetime psychiatric disorders with the Diagnostic Interview Schedule IV. Menstrual length and regularity were assessed by self-report. Analyses consisted of logistic regression while controlling for race. Independent of the effects of race, (a) women who reported irregular cycles were less than half as likely to have a current anxiety disorder as those that reported regular cycles, and (b) women with shorter cycles (<or=28 days) have one and a half times to two times greater risk of current affective disorder, lifetime affective disorder, lifetime anxiety disorder, lifetime substance use or dependence disorder, and lifetime drug abuse or dependence. A significant interaction effect for race and cycle length indicated that cycle length predicted likelihood of having any lifetime psychiatric disorder for Caucasians only and there was no association between cycle length and lifetime psychiatric diagnosis for African American women. | 18,809,118 |
Global health opportunities in surgery: a guide for medical students and faculty. | A four-week surgical rotation at the Clinica Universitaria Teleton in Chia, Colombia, was arranged for a U.S. student at the completion of the first year of medical school. The rotation resulted in a supervised intense early clinical exposure to surgery resulting in advancement in five of the six clinical competencies. International medical experiences can provide great benefit to U. S. medical students. | 18,809,171 |
Electron beam triggered, free radical polymerization-derived monolithic capillary columns for high-performance liquid chromatography. | Monolithic capillary columns were prepared via electron beam triggered free radical polymerization within the confines of 0.2 and 0.1mm I.D. capillary columns using ethyl methacrylate and trimethylolpropane triacrylate as monomers as well as 2-propanol, 1-dodecanol and toluene as porogenic system. The influence of column diameter on reproducibility and separation performance was investigated. For evaluation, a protein standard consisting of five proteins in the range of 5800-66,000 g mol(-1) was used. Reproducibility was checked by determining the relative standard deviations in retention times, peak widths at half height, asymmetry and resolution. Excellent run-to-run reproducibility was found for both 0.2 and 0.1mm I.D. columns; batch-to-batch reproducibility was good for both column types. In order to enhance the non-polar character of the monolithic columns, lauryl methacrylate-based capillary columns were prepared. These were successfully used for the separation of proteins and a cytochrome c digest. | 18,809,181 |
Demyelinating polyneuropathy with focally folded myelin sheaths in a family of Miniature Schnauzer dogs. | A spontaneous demyelinating polyneuropathy in two young Miniature Schnauzer dogs was characterized clinically, electrophysiologically and histopathologically. Both dogs were related and a third dog, belonging to the same family, had similar clinical signs. On presentation, clinical signs were restricted to respiratory dysfunction. Electrophysiological tests showed a dramatic decrease in both motor and sensory nerve conduction velocities. Microscopic examination of peripheral nerve biopsies (light and electron microscopy, teased nerve fibers), showed that this neuropathy was characterized by segmental demyelination and focally folded myelin sheaths. Various clinical syndromes associated with tomacula or focal thickening of the myelin sheath of the peripheral nerves have been described in humans and shown to be caused by gene mutations affecting the myelin proteins, such as the hereditary neuropathy with liability to pressure palsies or the demyelinating forms of Charcot-Marie-Tooth disease. In animals, a tomaculous neuropathy has been reported in cattle and chickens but not in carnivores. Here we report a demyelinating peripheral neuropathy with tomacula in two Miniature Schnauzer dogs. | 18,809,183 |
Mansonella perstans filariasis in Uganda: patterns of microfilaraemia and clinical manifestations in two endemic communities. | Surveys for Mansonella perstans infection and potentially related clinical manifestations were undertaken in two endemic communities in Mukono and Luwero districts of Uganda where no other human filarial infections are transmitted. A sensitive and accurate counting chamber method was used for quantifying microfilaraemia in 100microl of finger-prick blood. Among 575 and 991 examined individuals aged >or=1 year in the two communities, the overall microfilariae (mf) prevalence was significantly higher in Mukono (76.5%) than in Luwero (57.7%). As early as age 1-4 years, 40.6% and 20.5% of the children were mf-positive. Prevalences increased rapidly with increasing age to reach 89.2% and 81.4% in the 15-19 years age group and then remained high in subsequent age groups. The geometric mean mf intensity among mf-positive individuals was slightly higher in the Mukono community (32.4mf/100microl) than in the Luwero community (29.9mf/100microl), and this parameter increased with age in both communities. No obvious associations were observed between various clinical parameters and M. perstans microfilaraemia in any of the study communities. The observed patterns of microfilaraemia and the lack of obvious visible clinical manifestations suggest that the host's regulatory responses are downregulated in M. perstans infections. [ClinicalTrials.gov identifier: NCT00215280]. | 18,809,192 |
Modulation of redox pathways in neutrophils from sickle cell disease patients. | Interaction of nitric oxide (NO) with enzymatic sources of reactive species exerts modulatory actions on inflammatory signaling mechanisms. NADPH oxidase, total peroxidase, cyclooxygenase (COX) activity, and NO consumption were measured in neutrophils isolated from sickle cell disease (SCD) patients and healthy controls. Glutathione (GSH) levels and expression of inducible NO synthase (NOS-2) were also analyzed to assess intracellular redox state and NO production, respectively. Functional assay of NADPH oxidase was performed by measuring superoxide release, which was similar in control and SCD, both at basal conditions and in response to N-formyl-methionyl-leucyl-phenylalanine stimulation. Peroxidase activity, assessed spectrophotometrically, was not significantly different in SCD neutrophils compared to controls. Total COX activity, measured via an assay kit, was significantly increased in SCD neutrophils. The increase in total COX activity observed in SCD was due to enhanced activity of COX-2, differentiated by using the isoform-specific inhibitors DuP-697 and SC-560. Western blot analysis of COX-2 protein in SCD and control neutrophils confirmed increased enzyme activity in the diseased group. Western blot analysis of neutrophil lysates from SCD patients showed significantly increased NOS-2 protein content, compared to controls. Spectrophotometric measurement of GSH and nitrate/nitrite levels showed a decrease in GSH and an increase in nitrate/nitrite content in SCD neutrophils. Electrochemical measurement of NO consumption both under basal conditions and after N-formyl-methionyl-leucyl-phenylalanine stimulation revealed a significant decrease in SCD neutrophils compared to controls. Depletion of GSH in SCD neutrophils may impact on rates of NO consumption and reflects increased oxidative stress associated with neutrophil activation. | 18,809,239 |
Characterization of TiO(2)-chitosan/glass photocatalyst for the removal of a monoazo dye via photodegradation-adsorption process. | In this paper, the newly explored TiO(2)-Chitosan/Glass was suggested as a promising alternative material to conventional means of wastewater treatment. Characterization of TiO(2)-Chitosan/Glass photocatalyst was studied with SEM-EDX, XRD, and Fourier transform infrared spectroscopy (FTIR) analysis. The combination effect of photodegradation-adsorption process for the removal of methyl orange (MO), an acid dye of the monoazo series occur promisingly when four layers of TiO(2)-Chitosan/Glass photocatalyst was used for MO removal. Approximately, 87.0% of total MO removal was achieved. The reactive -NH(2), -OH, and metal oxide contents in the prepared photocatalyst responsible for the photodegradation-adsorption effect were confirmed by FTIR study. Similarly, MO removal behavior was well supported by SEM-EDX and XRD analysis. Significant dependence of MO removal on the TiO(2)-Chitosan loading can be explained in terms of relationship between quantum yield of photocatalytic reactions and photocatalyst structure/activity. Hence, the research work done thus far suggests a new method, having both the advantages of photodegradation-adsorption process in the abatement of various wastewater pollutants. | 18,809,254 |
Dynamic aortic changes in patients with thoracic aortic aneurysms evaluated with electrocardiography-triggered computed tomographic angiography before and after thoracic endovascular aneurysm repair: preliminary results. | The purpose of this study was to utilize dynamic computed tomographic angiography (CTA) on pre- and postoperative thoracic endovascular aneurysm repair (TEVAR) patients to characterize cardiac pulsatility-induced aortic motion on essential TEVAR proximal sealing zones and to study the influence of endograft placement. Six pre- and six postoperative dynamic CTA studies were obtained in six patients with thoracic aortic aneurysms (TAAs) undergoing TEVAR. Data were acquired using a retrospective electrocardiography-triggered dynamic CTA scan, with eight reconstructed phases over the cardiac cycle. Scans were acquired during a single breath hold. Multiplanar reconstructions were made perpendicular to the aorta at five surgically relevant anatomical thoracic landmarks: 1 cm proximal to the innominate trunk, 1 cm proximal and 1 cm distal to the left subclavian artery, and 1 cm proximal and 3 cm distal to the proximal end of the stent. After segmentation of the aortic lumen in the images, diameter change and area change over the cardiac cycle were measured. Diameter change was measured through the center of mass of the aortic lumen, and the average change over 180 axis is presented. We found significant distention of the thoracic aortic arch and descending thoracic aorta during the cardiac cycle before and after TEVAR. Distention ranged 3-12% in diameter and 2-20% in area. This distention was preserved after TEVAR. Patients with TAA experience aortic diameter and area changes during the cardiac cycle. The magnitude, and hence the clinical importance, of this aortic distention varies among patients. After stent-graft placement, aortic distention throughout the cardiac cycle is preserved. This may have major implications for correct sizing of the endograft as well as for stent-graft design and durability as the forces on the stents may be much larger after implantation than initially anticipated by stent manufacturers. | 18,809,281 |
Arteriovenous graft with outflow in the proximal axillary vein. | Arteriovenous access can result in complications including extremity ischemia and swelling. Use of the nondominant upper extremity is preferred because complications will result in less severe disability. The distal axillary vein in the axilla is usually considered to be the end point for arteriovenous access in the upper extremity. Vascular surgeons are familiar with exposure of the proximal axillary artery via an infraclavicular incision. The axillary vein is also easily exposed through this technique. Use of this vein for arteriovenous graft outflow can preserve the dominant arm for future use. Nine patients with arteriovenous grafts with venous outflow in the proximal arm for future use. All patients had exposure to the proximal axillary vein via an infraclavicular incision. There were six women and three men. All patients had multiple failed access in the ipsilateral extremity. One patient had a loop configuration graft, while the six others had a straight graft with arterial inflow via the brachial artery. One patient had a bovine mesenteric vein graft, while the remaining six had expanded polytetrafluoroethylene grafts. Six of the seven patients had ambulatory surgery, while one patient was admitted postoperatively with mental status changes. Patency rates were 78%, with mean follow-up of 16 months. One patient had early failure due to steal and one patient failed at 22 months. Six of seven patients are alive at current follow-up. Three patients required secondary procedures including venous angioplasty (n=2) and subclavian artery stenting (n=1). The infraclavicular axillary vein can be used as an effective outflow for arteriovenous grafts. This procedure can be done as an outpatient surgery with a low complication rate. This procedure can preserve the dominant arm for future access and provides a possible alternative to surgery on another extremity. | 18,809,289 |
Type A intramural hematoma presenting with acute right heart failure caused by compression of the main pulmonary artery: a case report. | Pulmonary artery obstruction is a rare complication of intramural hematoma of the ascending aorta. There were few reported cases presenting with right heart failure due to compression of the pulmonary trunk by intramural hematoma of the aorta. | 18,809,295 |
Marine diatoms as optical biosensors. | We have chemically modified the frustules of the marine diatom Coscinodiscus concinnus Wm. Smith to properly bind a highly selective bioprobe such as an antibody. By measuring the changes in the photoluminescence emission of diatoms frustules, we have monitored the molecular recognition event between the antibody and its ligand: the dissociation constant estimated is of the same order of that measured by standard Biacore. The nanostructured silica frustules, a low-cost and natural available material, have shown high sensitivity, equal to 1.2+/-0.2 nm microM(-1), and a detection limit of 100 nM, and thus are quite ideal candidates for lab-on-particle applications. | 18,809,311 |
Biodiesel production by in situ transesterification of municipal primary and secondary sludges. | The potential of using municipal wastewater sludges as a lipid feedstock for biodiesel production was investigated. Primary and secondary sludge samples obtained from a municipal wastewater treatment plant in Tuscaloosa, AL were freeze-dried and subjected to an acid-catalyzed insitu transesterification process. Experiments were conducted to determine the effects of temperature, sulfuric acid concentration, and mass ratio of methanol to sludge on the yield of fatty acid methyl esters (FAMEs). Results indicated a significant interactive effect between temperature, acid concentration, and methanol to sludge mass ratio on the FAME yield for the insitu transesterification of primary sludge, while the FAME yield for secondary sludge was significantly affected by the independent effects of the three factors investigated. The maximum FAME yields were obtained at 75 degrees C, 5% (v/v) H(2)SO(4), and 12:1 methanol to sludge mass ratio and were 14.5% and 2.5% for primary and secondary sludge, respectively. Gas chromatography (GC) analysis of the FAMEs revealed a similar fatty acid composition for both primary and secondary sludge. An economic analysis estimated the cost of $3.23/gallon for a neat biodiesel obtained from this process at an assumed yield of 10% FAMEs/dry weight of sludge. | 18,809,323 |
Extensive NMRD studies of Ni(II) salt solutions in water and water-glycerol mixtures. | Aqueous solutions of simple nickel(II) salts are a classical test case for theories of the paramagnetic relaxation enhancement (PRE) and its dependence on the magnetic field (nuclear magnetic relaxation dispersion, NMRD), going back to late fifties. We present here new experimental data, extending the NMRD range up to 21T (900 MHz). In addition to salt solutions in (acidified) water, we have also measured on solutions containing glycerol. The aqueous solution data do not show any significant changes compared to the earlier experiments. The interpretation, based on the general ("slow-motion") theory is also similar to the earlier work from our laboratory. The NMRD-data in mixed solvents are qualitatively different, indicating that the glycerol not only changes the solution viscosity, but may also enter the first coordination sphere of the metal ion, resulting in lower symmetry complexes, characterized by non-vanishing averaged zero-field splitting. This hypothesis is corroborated by molecular dynamics simulations. A strategy appropriate for interpreting the NMRD-data for the chemically complicated systems of this type is proposed. | 18,809,345 |
Insulin-like growth factor-I reduces stress-induced gastric mucosal injury by inhibiting neutrophil activation in mice. | We previously reported that activated neutrophils are critically involved in the development of stress-induced gastric mucosal injury in mice. Caspase activation plays an important role in the pathogenesis of tissue injury by activating neutrophils through an increase in the expression of endothelial monocyte-activating polypeptide-II (EMAP-II), a chemoattractant for neutrophils. Since insulin-like growth factor-I (IGF-I) inhibits caspase activation, it is possible that IGF-I reduces gastric mucosal injury by inhibiting neutrophil activation. In the present study, we examined this possibility in mice subjected to water-immersion restraint stress (WIR). Mice were intraperitoneally administered with IGF-I or vehicle before being subjected to WIR. Gastric mucosal injury, gastric myeloperoxidase (MPO) activity, the immunofluorescence intensity of MPO, caspase-3 activity, number of apoptotic cells, EMAP-II expression and activation of Akt and glycogen synthase kinase-3beta (GSK-3beta) in gastric mucosa were determined in mice subjected to WIR. Neutropenia was induced by administration of methotrexate (MTX). Administration of IGF-I at dosages higher than 200 microg/kg significantly reduced gastric mucosal injury and inhibited increases in gastric MPO activities after 8h of WIR. Administration of MTX also reduced the gastric mucosal injury as well as inhibiting increases in both gastric mucosal MPO activities and circulating neutrophil number. IGF-I (500 microg/kg) inhibited the increases in both gastric MPO activity and the immunofluorescence intensity of MPO observed in the gastric mucosa, but had no effect on the increase in circulating neutrophil number after 8h of WIR. It also markedly blunted WIR-induced increases in caspase-3 activities and the number of apoptotic cells in the gastric mucosa after 8h of WIR. Gastric expression of EMAP-II was markedly increased at 8h after starting WIR and this increase was inhibited by IGF-I administration. Administration of IGF-I enhanced WIR-induced phosphorylation of Akt and GSK-3beta in the gastric mucosa. These observations indicate that IGF-I reduces stress-induced gastric mucosal injury by inhibiting gastric accumulation of neutrophils through inhibition of caspase-3-mediated EMAP-II activation. Furthermore, IGF-I might inhibit caspase-3 activation through Akt/GSK-3beta signaling. | 18,809,348 |
A reliable confirmation of the chemical structure of synthetic oligonucleotides: detection of active protons in DNA oligomers by low-temperature FT infrared spectroscopy. | Cooling the samples allowed us to characterize solid oligonucleotides such as dimers, trimers and pentamers of cytidine, for the first time, in the IR range of the out-of-plane bending molecular modes (1000-400 cm(-1)) at 20K. Especially interesting are the narrow IR bands of the out-of-plane bending nu(4) NH(2) proton mode, which are apparently invisible at room temperature. This unequivocally defined and well-resolved NH(2) bending band should provide important information on the exact chemical form and hydrogen bonding interactions of cytidine amine groups. As such, this unique IR spectroscopy is suggested as a practical analytical tool to validate and characterize synthetic DNA bases and oligonucleotides. Using an approach of this type it was found that desalted oligonucleotide samples of the same nominal composition, but which had been produced by three different manufacturers, differ significantly in their IR spectra. These data suggest that the presumably identical oligonucleotides are in fact different, at least with respect to the content and nature of their NH protons. | 18,809,351 |
Regulation of brain insulin mRNA by glucose and glucagon-like peptide 1. | Whether the brain synthesizes insulin is currently debated. Two clonal, immortalized mouse hypothalamic cell lines from e17, mHypoE-39 and mHypoE-46, express insulin 2 (Ins2), but not Ins1. We analyzed regions necessary for basal gene activity and found that the mouse Ins2 region -110/+183 bp stimulates promoter activity in hypothalamic neurons. The rat Ins2 showed moderate activity, whereas the human promoter construct is repressed below basal levels. In MIN6 pancreatic beta-cells, all of the Ins1 and Ins2 promoter constructs display high levels of transcriptional activity. The cell lines also express components of glucose-sensing machinery and the endogenous glucagon-like peptide 1 receptor (Glp-1R). We observed that 16.7 mM glucose induces Ins2 mRNA, while forskolin and a Glp-1 agonist, exendin-4, induce a biphasic Ins2 mRNA response in mHypoE-39 neurons. The insulin cis-regulatory regions differ between the pancreas and the hypothalamus, and glucose and Glp-1 regulate the expression of hypothalamic insulin. | 18,809,381 |
Assessment of anxiety-like behaviors in female rats bred for differences in kindling susceptibility and amygdala excitability. | Two rat lines bred for kindling susceptibility were previously observed to engage in different behavioral strategies in tests of emotionality. In order to extend past research on defensive behaviors in these strains which largely used males, Fast- and Slow-kindling females were assessed for anxiety-like behaviors in a number of aversive paradigms. Fast rats entered and spent more time in the open arms and spent less time in the closed arms of the elevated plus-maze (EPM) compared to Slow animals. Fast rats had higher conditioned suppression ratios across testing days, defecated less often during conditioning, and successfully disinhibited suppression during extinction in the conditioned emotional response (CER) paradigm compared to Slow-kindlers. In order to pursue these differences in emotional reactivity between the strains and differentiate negative affect from motivational, learning, and impulsive explanations, a separate group of animals were assessed in the light-enhanced acoustic startle chamber, a test of anxiety. When initially exposed to a bright-light, Slow rats significantly increased their startle response while this was not observed in the Fast strain. In combination with previous research on these strains, the present data tentatively suggest that Fast and Slow animals utilize different neural systems in tests of fear and anxiety which may have been co-selected with the direct selection of amygdala-kindling susceptibility. | 18,809,390 |
Alpha-lipoic acid prevents mitochondrial damage and neurotoxicity in experimental chemotherapy neuropathy. | The study investigates if alpha-lipoic acid is neuroprotective against chemotherapy induced neurotoxicity, if mitochondrial damage plays a critical role in toxic neurodegenerative cascade, and if neuroprotective effects of alpha-lipoic acid depend on mitochondria protection. We used an in vitro model of chemotherapy induced peripheral neuropathy that closely mimic the in vivo condition by exposing primary cultures of dorsal root ganglion (DRG) sensory neurons to paclitaxel and cisplatin, two widely used and highly effective chemotherapeutic drugs. This approach allowed investigating the efficacy of alpha-lipoic acid in preventing axonal damage and apoptosis and the function and ultrastructural morphology of mitochondria after exposure to toxic agents and alpha-lipoic acid. Our results demonstrate that both cisplatin and paclitaxel cause early mitochondrial impairment with loss of membrane potential and induction of autophagic vacuoles in neurons. Alpha-lipoic acid exerts neuroprotective effects against chemotherapy induced neurotoxicity in sensory neurons: it rescues the mitochondrial toxicity and induces the expression of frataxin, an essential mitochondrial protein with anti-oxidant and chaperone properties. In conclusion mitochondrial toxicity is an early common event both in paclitaxel and cisplatin induced neurotoxicity. Alpha-lipoic acid protects sensory neurons through its anti-oxidant and mitochondrial regulatory functions, possibly inducing the expression of frataxin. These findings suggest that alpha-lipoic acid might reduce the risk of developing peripheral nerve toxicity in patients undergoing chemotherapy and encourage further confirmatory clinical trials. | 18,809,400 |
Physiological stress response of young adults exposed to bullying during adolescence. | Peer victimization in the form of bullying is a chronic social stressor experienced by many humans during development. Exposure to bullying has been associated with a variety of mental disorders, such as anxiety and depression. Participants pre-selected for the presence or absence of a history of being bullied were brought into a laboratory and placed in a stressful situation. Blood pressure, heart rate, and salivary cortisol levels were measured before the introduction of the stressor (Time 1), at the end of the stressor (Time 2), and after its removal (Time 3). Men with a history of exposure to frequent bullying showed blunted blood pressure responses at Time 2 compared to control men. Bullied and Non-bullied women did not show any differences in any of the measures. Men and women in both groups showed an increase in heart rate in response to the stressor. There were no significant differences in salivary cortisol levels between Bullied and Non-bullied participants. However, salivary cortisol levels and systolic blood pressure were lower in Bullied male participants who reported having no feelings of anger about their experience compared to controls and those who did report anger. These data show altered sympathetic responses to stress in men with a history of victimization as well as suggesting long-term effects on the HPA axis in the most affected individuals. | 18,809,422 |
The function of rhamnose-binding lectin in innate immunity by restricted binding to Gb3. | L-rhamnose-binding lectins (RBLs) have been isolated from various kinds of fish and invertebrates and interact with various kinds of bacteria, suggesting RBLs are involved in various inflammatory reactions. We investigated the effect of RBLs from chum salmon (Oncorhynchus keta), named CSL1, 2 and 3, on the peritoneal macrophage cell line from rainbow trout (Oncorhynchus mykiss) (RTM5) and an established fibroblastic-like cell line derived from gonadal tissue of rainbow trout (RTG-2). CSLs were bound to the surface of RTM5 and RTG-2 cells and induced proinflammatory cytokines, including IL-1beta1, IL-1beta2, TNF-alpha1, TNF-alpha2 and IL-8 in both cells by recognizing globotriaosylceramide (Gb3). In addition, CSLs had an opsonic effect on RTM5 cells and this effect was significantly inhibited by L-rhamnose, indicating that CSLs enhanced their phagocytosis by binding to Gb3 on cell surfaces. This is the first finding that Gb3 plays a role in innate immunity by cooperating with natural ligands, RBLs. | 18,809,432 |
Striatal volume differences between non-human and human primates. | Convection-enhanced delivery (CED) has recently entered the clinic and represents a promising new delivery option for targeted gene therapy in Parkinson's disease (PD). The prime stereotactic target for the majority of recent gene therapy clinical trials has been the human putamen. The stereotactic delivery of therapeutic agents into putamen (or other subcortical structures) via CED remains problematic due to the difficulty in knowing what volume of therapeutic agent to deliver. Preclinical studies in non-human primates (NHP) offer a way to model treatment strategies prior to clinical trials. Understanding more accurately the volumetric differences in striatum, especially putamen, between NHP and humans is essential in predicting convective volume parameters in human clinical trials. In this study, magnetic resonance images (MRI) were obtained for volumetric measurements of striatum (putamen and caudate nucleus) and whole brain from 11 PD patients, 13 aged healthy human subjects, as well as 8 parkinsonian and 30 normal NHP. The human brain is 13-18 times larger than the monkey brain. However, this ratio is significantly smaller for striatum (5.7-6.5), caudate nucleus (4.6-6.6) and putamen (4.4-6.6). Size and species of the monkeys used for this comparative study are responsible for differences in ratios for each structure between monkeys and humans. This volumetric ratio may have important implications in the design of clinical therapies for PD and Huntington's disease and should be considered when local therapies such as gene transfer, local protein administration or cellular replacement are translated based on NHP research. | 18,809,434 |
Complex dynamics of microbial competition in the gradostat. | We examine the conditions necessary for the emergence of complex dynamic behavior in systems of microbial competition. In particular, we study the effect of spatial heterogeneity and substrate-inhibition on the dynamics of such a system. This is accomplished through the study of a mathematical model of two microbial populations competing for a single nutrient in a configuration of two interconnected chemostats. Microbial growth is assumed to follow substrate-inhibited kinetics for both species. Such a system with sterile feed has been shown in a previous work to exhibit stable periodic states. In the present work we study the system for the case of non-sterile feed, i.e., when the two species are present in the feed of the chemostats. The analysis is done by numerical bifurcation theory methods. We demonstrate that, in addition to periodic states, the system possesses stable quasi-periodic states resulting from Neimark-Sacker bifurcations of limit cycles. Also, periodic states may undergo successive period doublings leading to periodic states of increasing period and indicating that chaotic states might be possible. Multistability is also observed, consisting in the coexistence of several stable steady states and possibly stable periodic or quasi-periodic states for given operating conditions. It appears that substrate-inhibition, spatial heterogeneity and presence of microorganisms in the inflow are all necessary conditions for complex dynamics to arise in a microbial system of pure and simple competition. | 18,809,443 |
Effects of dietary selenium supplementation on serum and liver selenium, serum malondialdehyde and liver glutathione peroxidase activity in rats consuming thermally oxidized sunflower oil. | The present study compared the effects of four isocaloric diets containing (1) fresh sunflower oil not supplemented with selenium (Fresh), (2) oxidized sunflower oil not supplemented with selenium (Oxidized), (3) fresh sunflower oil supplemented with 1 ppm selenium as sodium selenite (Fresh+Se), (4) oxidized sunflower oil supplemented with 1 ppm selenium as sodium selenite (Oxidized+Se) on serum MDA concentrations, liver GPx activity and serum and liver selenium contents in growing male Sprague Dawley rats during a period of 43 days. The oxidized oil used was prepared by heating fresh sunflower oil at 180 degrees C for 48 h. Serum and liver selenium contents and liver GPx activity were significantly higher in the selenium supplemented groups compared to the non-selenium supplemented groups, but these parameters did not differ significantly between the oxidized oil fed groups and the fresh oil fed groups. Serum MDA concentrations increased significantly in the Oxidized group compared to the Fresh group. This suggests that the ingestion of oxidized oil resulted in, in vivo lipid peroxidation. Serum MDA concentrations remained significantly higher even in comparison of the Oxidized + Se group with the Oxidized group. Our results emphasize that the consumption of oxidized oil increases in vivo lipid peroxidation and thus can be deleterious to health. However, we did not observe a significant beneficial effect of selenium supplementation upon the ingestion of thermally oxidized oil on lipid peroxidation. | 18,809,457 |
FGF-8 stimulates the expression of NR4A orphan nuclear receptors in osteoblasts. | Nurr1, NGFI-B, and Nor1 form the NR4A subfamily of orphan nuclear receptors. The NR4A receptors are immediate early genes that can be rapidly induced in response to a variety of stimuli in many cell types, for example, in osteoblasts. Nurr1 regulates the differentiation of osteoblasts and the expression of several osteoblastic genes. Fibroblast growth factor 8b (FGF-8b) regulates osteoblastic differentiation. We show here that treatment of preosteoblastic MC3T3-E1 cells or mouse bone marrow mesenchymal cells with FGF-8b induces the expression of NR4A receptors rapidly and in a dose-dependent manner. This induction involves mitogen-activated protein kinase (MAPK), phosphatidylinositol-3-kinase (PI-3K), and protein kinase C (PKC) pathways. FGF-8b stimulates the proliferation of MC3T3-E1 cells. This effect is enhanced by overexpression of Nurr1 and NGFI-B whereas it is abolished by a dominant negative Nurr1 variant. In conclusion, FGF-8b induces the expression of NR4A orphan nuclear receptors that are involved in mediating the growth promoting effect of FGF-8b in osteoblasts. | 18,809,462 |
The energy hypothesis of sleep revisited. | One of the proposed functions of sleep is to replenish energy stores in the brain that have been depleted during wakefulness. Benington and Heller formulated a version of the energy hypothesis of sleep in terms of the metabolites adenosine and glycogen. They postulated that during wakefulness, adenosine increases and astrocytic glycogen decreases reflecting the increased energetic demand of wakefulness. We review recent studies on adenosine and glycogen stimulated by this hypothesis. We also discuss other evidence that wakefulness is an energetic challenge to the brain including the unfolded protein response, the electron transport chain, NPAS2, AMP-activated protein kinase, the astrocyte-neuron lactate shuttle, production of reactive oxygen species and uncoupling proteins. We believe the available evidence supports the notion that wakefulness is an energetic challenge to the brain, and that sleep restores energy balance in the brain, although the mechanisms by which this is accomplished are considerably more complex than envisaged by Benington and Heller. | 18,809,461 |
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