title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
|---|---|---|
The Milwaukee Inventory for the Dimensions of Adult Skin Picking (MIDAS): initial development and psychometric properties. | This article describes the development and initial psychometric properties of the Milwaukee Inventory for the Dimensions of Adult Skin picking (MIDAS), a measure designed to assess "automatic" and "focused" skin picking. Data were collected from 92 participants who completed an anonymous internet-based survey. Results of an exploratory factor analysis revealed a two-factor solution. Factors 1 ("focused" picking scale) and 2 ("automatic" picking scale) each consisted of 6 items, and preliminary data demonstrated adequate internal consistency, good construct validity, and good discriminant validity. The MIDAS provides researchers with a reliable and valid assessment of "automatic" and "focused" skin picking. | 18,725,154 |
Cost-minimization analysis of jumbo reusable forceps versus disposable forceps in a high-volume ambulatory endoscopy center. | Endoscopists worldwide are faced with the challenge of choosing the most cost-effective and durable equipment. There are limited data comparing the 2 major options for endoscopic forceps: disposable and reusable. Disposable forceps are marketed as the cost-effective alternative to reusable forceps. This study was designed to provide a prospective assessment of the survival and cost of reusable versus disposable forceps to allow more educated decisions when purchasing endoscopic equipment. A 24-month prospective study in a high-volume ambulatory endoscopy center (AEC) with 71 Olympus jumbo reusable forceps (OJRF). A "cost of OJRF per procedure" was generated to compare to the estimated cost of disposable forceps per procedure. Gastrointestinal Associates PA of Jackson, Mississippi, which performs approximately 24,000 outpatient procedures per year. General patient population of this AEC undergoing colonoscopy. Mean cost of forceps per procedure and survival of reusable forceps. Cost was derived from purchase price, cleaning costs, repair/maintenance costs, and number of uses. Over the 24-month period, the total cost per procedure was $3.27. The mean number of uses per OJRF was 166.3. Sixty-eight percent of the forceps required no repair throughout the 2-year study, and only 1 forceps was deemed beyond repair. For comparison, disposable forceps were assigned a cost per procedure of $10.00 on the basis of conservative market price. Over a 2-year period this cost-per-procedure difference resulted in a cost savings of $79,482. Failure to determine the average life-span of OJRF because 98% were still functioning properly after 2 years and an average of 166.3 procedures. Evaluation did not include storage and disposal costs, which would add a miniscule additional cost to disposable costs. The study also does not address some of the other arguments for disposables such as performance (quality of specimen) compared with reusables. The estimated average number of uses and durability was only studied for the OJRF. Other forceps may have different average cost per use and durability. In a large-volume AEC, OJRF are vastly more durable than resusable forceps reported in prior studies and are vastly more cost-effective than disposable forceps. A longer study period would have only revealed more dramatic cost savings and durability. | 18,725,156 |
Nephrin and podocin loss is prevented by mycophenolate mofetil in early experimental diabetic nephropathy. | Several works in the setting of early experimental diabetic nephropathy using anti-inflammatory drugs, such as mycophenolate mofetil (MMF), have shown that prevention of the development or amelioration of renal injury including proteinuria. The exact mechanisms by which anti-inflammatory drugs lower the albuminuria have no still to clarify well. In this study, diabetes was induced by injection of streptozotocin after uninephrectomy. Rats were randomly divided into three groups: control group, diabetic group and diabetic group treated with MMF. Elevated 24h urinary albumin excretion rate was markedly attenuated by MMF treatment. In diabetic rats receiving no treatment, there were increase in ED-1+ cells in the glomeruli, which were effectively suppressed by MMF treatment. The expression of nephrin and podocin protein was reduced in the glomeruli from diabetic rats, and MMF treatment significantly increased the expression of nephrin and podocin. The expression of IL-1, TNF-alpha and 3-NT protein in the glomeruli were significantly increased in diabetic rats, which were all significantly inhibited by MMF treatment. Our results show that MMF could decrease urinary albumin excretion, which mechanism may be at least partly correlated with upregulated expression of nephrin and podocin in the glomeruli of diabetic rat. | 18,725,182 |
A Q312X mutation in the hemojuvelin gene is associated with cardiomyopathy due to juvenile haemochromatosis. | Juvenile haemochromatosis (JH) is an autosomal recessive iron disorder characterized by the early onset of secondary cardiomyopathy. The candidate modifier genes are hemojuvelin (HJV) and hepcidin antimicrobial peptide (HAMP). In the Japanese population, the prevalence of JH is quite low. The influence of HJV mutation on the JH phenotype is still unclear. We searched for possible mutations in a Japanese family with 2 members who were JH patients with severe heart failure. To search for possible variants in the HJV and HAMP genes, we performed direct sequencing in the family members. A homozygous nonsense mutation in exon 4 of HJV (Q312X) was identified in the JH patients and their mother. Three individuals in the family were heterozygous for this mutation. Subsequently, we evaluated the frequency of Q312X mutation in a large population (n=361) without heart failure, using allele-specific real-time PCR assay. No Q312X mutation was detected in this population. In the patients with the homozygous HJV mutation, iron loading revealed high serum ferritin concentration with accompanying elevated transferrin iron saturation. In contrast, ferritin levels were within the normal range in individuals with the heterozygous mutation. We found a nonsense mutation in the HJV gene. This mutation elevates ferritin levels and leads to JH associated with severe cardiomyopathy. | 18,725,184 |
Immunotherapy of hepatocellular carcinoma with a vaccine based on xenogeneic homologous alpha fetoprotein in mice. | alpha-Fetoprotein (AFP) is a diagnostic marker for the presence of hepatocellular carcinoma, and a potential target for immunotherapy. Unfortunately, the immunity to AFP is presumably difficult to elicit because of immune tolerance acquired during the development of immune system. In the present study, we used AFP as a model antigen to explore the feasibility of the immunotherapy of AFP-positive liver cancer by the breaking of immune tolerance against AFP in a cross-reaction between the xenogeneic homologues and self molecules. Recombinant rat AFP was prepared as a vaccine, and mouse AFP was prepared as a control. Immunized with rat AFP was effective at protective and therapeutic antitumor immunity in hepatocellular carcinoma model in mice. Both humoral and cellular immune responses may be responsible for the antitumor activity against AFP-positive tumor cells, and no marked side effects were observed in the immunized mice. Thus, our study may provide an effective vaccine strategy for the treatment of AFP-positive hepatocellular carcinoma, and may be of importance to further exploration of the breaking of immune tolerance to self molecules. | 18,725,206 |
In silico identification of anthropogenic chemicals as ligands of zebrafish sex hormone binding globulin. | Anthropogenic compounds with the capacity to interact with the steroid-binding site of sex hormone binding globulin (SHBG) pose health risks to humans and other vertebrates including fish. Building on studies of human SHBG, we have applied in silico drug discovery methods to identify potential binders for SHBG in zebrafish (Danio rerio) as a model aquatic organism. Computational methods, including; homology modeling, molecular dynamics simulations, virtual screening, and 3D QSAR analysis, successfully identified 6 non-steroidal substances from the ZINC chemical database that bind to zebrafish SHBG (zfSHBG) with low-micromolar to nanomolar affinities, as determined by a competitive ligand-binding assay. We also screened 80,000 commercial substances listed by the European Chemicals Bureau and Environment Canada, and 6 non-steroidal hits from this in silico screen were tested experimentally for zfSHBG binding. All 6 of these compounds displaced the [(3)H]5alpha-dihydrotestosterone used as labeled ligand in the zfSHBG screening assay when tested at a 33 microM concentration, and 3 of them (hexestrol, 4-tert-octylcatechol, and dihydrobenzo(a)pyren-7(8H)-one) bind to zfSHBG in the micromolar range. The study demonstrates the feasibility of large-scale in silico screening of anthropogenic compounds that may disrupt or highjack functionally important protein:ligand interactions. Such studies could increase the awareness of hazards posed by existing commercial chemicals at relatively low cost. | 18,725,242 |
Dual-probe real-time PCR assay for detection of variola or other orthopoxviruses with dried reagents. | A real-time, multiplexed polymerase chain reaction (PCR) assay based on dried PCR reagents was developed. Only variola virus could be specifically detected by a FAM (6-carboxyfluorescein)-labeled probe while camelpox, cowpox, monkeypox and vaccinia viruses could be detected by a TET (6-carboxytetramethylrhodamine)-labeled probe in a single PCR reaction. Approximately 25 copies of cloned variola virus DNA and 50 copies of genomic orthopoxviruses DNA could be detected with high reproducibility. The assay exhibited a dynamic range of seven orders of magnitude with a correlation coefficient value greater than 0.97. The sensitivity and specificity of the assay, as determined from 100 samples that contained nucleic acids from a multitude of bacterial and viral species were 96% and 98%, respectively. The limit of detection, sensitivity and specificity of the assay were comparable to standard real-time PCR assays with wet reagents. Employing a multiplexed format in this assay allows simultaneous discrimination of the variola virus from other closely related orthopoxviruses. Furthermore, the implementation of dried reagents in real-time PCR assays is an important step towards simplifying such assays and allowing their use in areas where cold storage is not easily accessible. | 18,725,245 |
Are oscillatory brain responses generally reduced in schizophrenia during long sustained attentional processing? | Deficits in sustained attention and vigilance were assessed for oscillatory delta, theta, alpha, and gamma EEG activity during an auditory continuous performance task in patients with schizophrenia and healthy controls by quantifying peak-to-peak amplitudes of averaged and single-trial data. Averaged data indicated significantly reduced amplitudes in schizophrenia patients in all analyzed frequency bands, mainly at anterior locations. Single-trial analysis suggested that the amplitude reductions observed in the averaged delta, theta, and alpha response in patients originated from increased inter-trial phase variability. Gamma activity maximum amplitudes were reduced at the single-trial level. The findings imply that EEG activity in patients with schizophrenia can be characterized by multiple deficits in oscillatory networks, which indicates a disturbance in the temporal integration and interaction of all frequency components and their inter-trial variability. | 18,725,254 |
Targeting subcapsular antigens for prevention of Klebsiella pneumoniae infections. | Vaccination strategies against Klebsiella pneumoniae have largely focussed on the polysaccharide capsule. However, the large number and high prevalence of individual capsular serotypes limits the widespread applicability of capsule-based vaccines. This study establishes that immunization with purified LPS can protect mice against lethal challenge with K. pneumoniae, and that subcapsular antibodies directed against purified LPS can be used to treat and/or prevent experimental K. pneumoniae infection in mice. This approach offers potential for prophylaxis and/or therapy against drug-resistant strains of K. pneumoniae. | 18,725,260 |
Aflatoxin B1-induced TP53 mutational pattern in normal human cells using the FASAY (Functional Analysis of Separated Alleles in Yeast). | Mutations in the TP53 gene are the most common alterations in human tumours. In hepatocellular carcinoma (HCC) related to exposure to aflatoxin B1, a specific G>T transversion in codon 249 is classically described as a hot spot. However, AFB1 is suspected to be a potent carcinogen in tissues other than the liver. By using the FASAY functional assay in yeast, the present study aimed at depicting the mutational pattern of TP53 in normal human fibroblasts after in vitro exposure to AFB1. Molecular analysis of mutants revealed that codon 245 was the main hot spot, whereas no mutations were found in codon 249. The locations of mutations within GG and GC/CG sequences are well in accordance with AFB1-adduct location data. In our assay with normal human fibroblasts, AFB1 mainly induced G>A transitions, followed by G>T and A>G mutations. This suggests that G>T transversions at codon 249 were likely the result of a selection bias in human HCC rather than a true fingerprint of AFB1 adducts. Indeed, a comparison of the mutation pattern with that found in human HCC excluding codon 249 reveals that the two spectra are quite similar. Furthermore, the similarity between our in vitro spectrum with that identified in AFB1-induced lung tumours in mice suggests that AFB1 may be a potent lung carcinogen in humans. | 18,725,321 |
Heavy metals generate reactive oxygen species in terrestrial and aquatic ciliated protozoa. | Reactive oxygen species (ROS) induction by exposure to heavy metals (Cd, Cu or Zn) in diverse free-living ciliated protozoa (Tetrahymena sp. and three strains of Colpoda steinii, isolated from freshwater and soils with different level of metal pollution) has been evaluated. Using specific fluorophores, such as 2',7'-dichlorofluorescein diacetate, hydroethidine and dihydrorhodamine 123, and a fluorescence microscope with the program MetaMorph Imaging System 4.0, we have analyzed both the average fluorescence emission and the heterogeneous distribution of fluorescence in control and treated cells. This is the first time that these fluorophores are used to detect ROS production in ciliated protozoa. All metals generate ROS, mainly superoxide and peroxides, showing a remarkable inter- and intra-specific variations. Likewise, resistance against each metal was also very diverse. Cu and specially Cd, the most toxic heavy metal for these ciliates, are the best oxidative stress inducers. However, a correlation between fluorescence emission intensity and cellular metal sensitivity for each strain cannot be established. Results are discussed and compared with similar findings previously published in other unicellular and pluricellular organisms. | 18,725,323 |
[A monoclonal immunoglobulin M not visible on the profile of serum capillary electrophoresis]. | We report a case of an invisible monoclonal IgM on the profile of the serum electrophoresis carried out by the Paragon CZE 2000 system. This case is about a 84 years old man followed for a Waldenström disease. The level of the monoclonal IgM given at the time of the preceding visit one year before was 10 g/L. The electrophoresis is reproduced in two other laboratories using respectively the Hydrasys and Capillarys techniques which have both shown the presence of the monoclonal peak. At this occasion the frequency of these anomalies of migration and the recommendations to avoid the erroneous interpretation of the electrophoresis are discussed. The vigilance and the competence of the biologist are essential to avoid this rare pitfall, induced by the new principle of the capillary electrophoresis. | 18,725,351 |
[PPAR alpha-L162V, frequency and relationship with type 2 diabetes among black Senegalese people]. | PPARs are supposed to be involved in pathogenesis of diabetes and its complications. According to some authors, L162V PPARalpha gene polymorphism would be associated to dyslipidemia susceptibility during diabetes, whereas for some authors, it rather would confer resistance to these metabolic abnormalities. The aim of this study is to search the relationship between this polymorphism and the occurrence of diabetes and its complications within a Senegalese black population constituted of 261 diabetic and 128 controls, by comparing alleles frequencies. Genomic analysis for alleles identification has been performed by the allelic discrimination technic TaqMan 5' Nuclease, after DNA extraction (Nucleon Bacc2. Amersham Int.). The results of genetic variants analysis revealed that L162V PPARalpha polymorphism would not be present among Senegalese black population, and consequently, should not be involved in diabetes onset. | 18,725,353 |
The impact of statin use on atrial fibrillation. | The aim of the present systematic review is to present an overview of the evidence linking atrial fibrillation (AF), inflammation and oxidative stress, with emphasis on the potential of statins to decrease the incidence of different types of AF, including new-onset AF, after electrical cardioversion (EC) and after cardiac surgery. Observational and clinical trials have studied the impact of statin therapy on new-onset, post-EC or postoperative AF. Data from different observational trials have shown that treatment with statins significantly reduces the incidence of new-onset AF in the primary and secondary prevention. The data are insufficient to recommend the use of statins before EC. Finally, perioperative statin therapy may represent an important non-antiarrhythmic adjunctive therapeutic strategy for the prevention of postoperative AF. | 18,725,372 |
Obtaining utility estimates of the health value of commonly prescribed treatments for asthma and depression. | Comparing the costs and health value associated with alternative quality improvement efforts is useful. This study employs expert panel methodology to elicit numerical estimates based on a 0 to 1 utility scale of the health benefit of usual treatment patterns for 2 medical conditions. The approach includes development of clinical profiles and derivation of treatment benefit estimates via the elicitation of utility ratings before and after treatment. Clinical profiles specified characteristics of patient groups, treatments to be rated, and their combinations. A panel of 13 asthma and depression experts made a series of utility ratings (before any new treatment, 1 or 3 mo later with no treatment, 1 or 3 mo after initiating various common treatments) for adult patient groups with depression or asthma. The panel convened to discuss discrepancies and subsequently made final ratings. Treatment benefit estimates were derived from the ratings made by the panelists after the panel meeting. The treatment benefit estimates had face validity and minimal variability, indicating considerable consensus among experts. Treatment benefit estimates ranged from -0.03 to 0.25 for depression and from -0.04 to 0.24 for asthma. There was minimal variation in the estimates for both conditions (the estimates' standard deviations ranged from 0.01 to 0.06). Comparisons of the treatment benefit estimates before and after the expert panel meeting indicated substantial convergence, and evidence suggests that the benefit estimates are comparable across the 2 health conditions. Comparable estimates of treatment benefit for distinct health conditions can be obtained from experts using the expert panel methodology. | 18,725,407 |
Functional adhesiveness of the CX3CL1 chemokine requires its aggregation. Role of the transmembrane domain. | In its native form, the chemokine CX3CL1 is a firmly adhesive molecule promoting leukocyte adhesion and migration and hence involved, along with its unique receptor CX3CR1, in various inflammatory processes. Here we investigated the role of molecular aggregation in the CX3CL1 adhesiveness. Assays of bioluminescence resonance energy transfer (BRET) and homogeneous time-resolved fluorescence (HTRF) in transfected cell lines and in primary cells showed specific signals indicative of CX3CL1 clustering. Truncation experiments showed that the transmembrane domain played a central role in this aggregation. A chimera with mutations of the 12 central transmembrane domain residues had significantly reduced BRET signals and characteristics of a non-clustering molecule. This mutant was weakly adhesive according to flow and dual pipette adhesion assays and was less glycosylated than CX3CL1, although, as we demonstrated, loss of glycosylation did not affect the CX3CL1 adhesive potency. We postulate that cell surfaces express CX3CL1 as a constitutive oligomer and that this oligomerization is essential for its adhesive potency. Inhibition of CX3CL1 self-assembly could limit the recruitment of CX3CR1-positive cells and may be a new pathway for anti-inflammatory therapies. | 18,725,411 |
The diversity of O-linked glycans expressed during Drosophila melanogaster development reflects stage- and tissue-specific requirements for cell signaling. | Appropriate glycoprotein O-glycosylation is essential for normal development and tissue function in multicellular organisms. To comprehensively assess the developmental and functional impact of altered O-glycosylation, we have extensively analyzed the non-glycosaminoglycan, O-linked glycans expressed in Drosophila embryos. Through multidimensional mass spectrometric analysis of glycans released from glycoproteins by beta-elimination, we detected novel as well as previously reported O-glycans that exhibit developmentally modulated expression. The core 1 mucin-type disaccharide (Galbeta1-3GalNAc) is the predominant glycan in the total profile. HexNAcitol, hexitol, xylosylated hexitol, and branching extension of core 1 with HexNAc (to generate core 2 glycans) were also evident following release and reduction. After Galbeta1-3GalNAc, the next most prevalent glycans were a mixture of novel, isobaric, linear, and branched forms of a glucuronyl core 1 disaccharide. Other less prevalent structures were also extended with HexA, including an O-fucose glycan. Although the expected disaccharide product of the Fringe glycosyltransferase, (GlcNAcbeta1-3)fucitol, was not detectable in whole embryos, mass spectrometry fragmentation and exoglycosidase sensitivity defined a novel glucuronyl trisaccharide as GlcNAcbeta1-3(GlcAbeta1-4)fucitol. Consistent with the spatial distribution of the Fringe function, the GlcA-extended form of the Fringe product was enriched in the dorsal portion of the wing imaginal disc. Furthermore, loss of Fringe activity reduced the prevalence of the O-Fuc trisaccharide. Therefore, O-Fuc glycans necessary for the modulation of important signaling events in Drosophila are, as in vertebrates, substrates for extension beyond the addition of a single HexNAc. | 18,725,413 |
Protein-tyrosine phosphatase alpha regulates stem cell factor-dependent c-Kit activation and migration of mast cells. | The role of protein-tyrosine phosphatase alpha (PTPalpha) in mast cell function was investigated in tissues and cells from PTPalpha-deficient mice. Bone marrow-derived mast cells (BMMCs) lacking PTPalpha exhibit defective stem cell factor (SCF)-dependent polarization and migration. Investigation of the molecular basis for this reveals that SCF/c-Kit-stimulated activation of the Fyn tyrosine kinase is impaired in PTPalpha(-/-) BMMCs, with a consequent inhibition of site-specific c-Kit phosphorylation at tyrosines 567/569 and 719. Although c-Kit-mediated activation of phosphatidylinositol 3-kinase and Akt is unaffected, profound defects occur in the activation of downstream signaling proteins, including mitogen-activated protein kinases and Rho GTPases. Phosphorylation and interaction of Fyn effectors Gab2 and Shp2, which are linked to Rac/JNK activation in mast cells, are impaired in PTPalpha(-/-) BMMCs. Thus, PTPalpha is required for SCF-induced c-Kit and Fyn activation, and in this way regulates a Fyn-based c-Kit signaling axis (Fyn/Gab2/Shp2/Vav/PAK/Rac/JNK) that mediates mast cell migration. These defective signaling events may underlie the altered tissue-resident mast cell populations found in PTPalpha(-/-) mice. | 18,725,415 |
Molecular basis of the Bohr effect in arthropod hemocyanin. | Flash photolysis and K-edge x-ray absorption spectroscopy (XAS) were used to investigate the functional and structural effects of pH on the oxygen affinity of three homologous arthropod hemocyanins (Hcs). Flash photolysis measurements showed that the well-characterized pH dependence of oxygen affinity (Bohr effect) is attributable to changes in the oxygen binding rate constant, k(on), rather than changes in k(off). In parallel, coordination geometry of copper in Hc was evaluated as a function of pH by XAS. It was found that the geometry of copper in the oxygenated protein is unchanged at all pH values investigated, while significant changes were observed for the deoxygenated protein as a function of pH. The interpretation of these changes was based on previously described correlations between spectral lineshape and coordination geometry obtained for model compounds of known structure (Blackburn, N. J., Strange, R. W., Reedijk, J., Volbeda, A., Farooq, A., Karlin, K. D., and Zubieta, J. (1989) Inorg. Chem., 28, 1349-1357). A pH-dependent change in the geometry of cuprous copper in the active site of deoxyHc, from pseudotetrahedral toward trigonal was assigned from the observed intensity dependence of the 1s --> 4p(z) transition in x-ray absorption near edge structure (XANES) spectra. The structural alteration correlated well with increase in oxygen affinity at alkaline pH determined in flash photolysis experiments. These results suggest that the oxygen binding rate in deoxyHc depends on the coordination geometry of Cu(I) and suggest a structural origin for the Bohr effect in arthropod Hcs. | 18,725,416 |
Delta protein kinase C interacts with the d subunit of the F1F0 ATPase in neonatal cardiac myocytes exposed to hypoxia or phorbol ester. Implications for F1F0 ATPase regulation. | Mitochondrial protein kinase C isozymes have been reported to mediate both cardiac ischemic preconditioning and ischemia/reperfusion injury. In addition, cardiac preconditioning improves the recovery of ATP levels after ischemia/reperfusion injury. We have, therefore, evaluated protein kinase C modulation of the F(1)F(0) ATPase in neonatal cardiac myocytes. Exposure of cells to 3 or 100 nM 4beta-phorbol 12-myristate-13-acetate induced co-immunoprecipitation of delta protein kinase C (but not alpha, epsilon, or zeta protein kinase C) with the d subunit of the F(1)F(0) ATPase. This co-immunoprecipitation correlated with 40+/-3% and 72+/-9% inhibitions of oligomycin-sensitive F(1)F(0) ATPase activity, respectively. We observed prominent expression of delta protein kinase C in cardiac myocyte mitochondria, which was enhanced following a 4-h hypoxia exposure. In contrast, hypoxia decreased mitochondrial zetaPKC levels by 85+/-1%. Following 4 h of hypoxia, F(1)F(0) ATPase activity was inhibited by 75+/-9% and delta protein kinase C co-immunoprecipitated with the d subunit of F(1)F(0) ATPase. In vitro incubation of protein kinase C with F(1)F(0) ATPase enhanced F(1)F(0) activity in the absence of protein kinase C activators and inhibited it in the presence of activators. Recombinant delta protein kinase C also inhibited F(1)F(0) ATPase activity. Protein kinase C overlay assays revealed delta protein kinase C binding to the d subunit of F(1)F(0) ATPase, which was modulated by diacylglycerol, phosphatidylserine, and cardiolipin. Our results suggest a novel regulation of the F(1)F(0) ATPase by the delta protein kinase C isozyme. | 18,725,417 |
ZapA, a virulence factor in a rat model of Proteus mirabilis-induced acute and chronic prostatitis. | Our knowledge of pathogenesis has benefited from a better understanding of the roles of specific virulence factors in disease. To determine the role of the virulence factor ZapA, a 54-kDa metalloproteinase of Proteus mirabilis, in prostatitis, rats were infected with either wild-type (WT) P. mirabilis or its isogenic ZapA(-) mutant KW360. The WT produced both acute and chronic prostatitis showing the typical histological progressions that are the hallmarks of these diseases. Infection with the ZapA(-) mutant, however, resulted in reduced levels of acute prostatitis, as determined from lower levels of tissue damage, bacterial colonization, and inflammation. Further, the ZapA(-) mutant failed to establish a chronic infection, in that bacteria were cleared from the prostate, inflammation was resolved, and tissue was seen to be healing. Clearance from the prostate was not the result of a reduced capacity of the ZapA(-) mutant to form biofilms in vitro. These finding clearly define ZapA as an important virulence factor in both acute and chronic bacterial prostatitis. | 18,725,420 |
The roles of physiological and subjective stress in the effectiveness of a placebo on experimentally induced pain. | To examine whether reduction of negative emotions and associated autonomic activity could explain placebo analgesia, and to test the effect of experimenter gender on the placebo analgesic response. Sixty-three (n = 32 females) students participated in a within-subjects design where subjects were tested on two separate days, one day for the experimental condition (placebo) and one day for the natural history condition. In the experimental condition, the participants received capsules containing lactose with information that the capsules were a high dose of a potent painkiller. In the natural history condition, the procedures were identical except that the placebo capsules were not administrated. The experimenters were blinded to the fact that all participants received placebo. Pain was induced by a thermode holding +46 degrees C with duration of 240 seconds to the forearm. Electrocardiogram was measured to obtain data for analysis of heart rate variability. Subjective measurements consisted of pain intensity, pain unpleasantness, stress, arousal, and mood. The results showed a placebo effect on pain intensity and a concomitant reduction in subjective stress and cardiac activity. Stepwise regressions revealed that reduced subjective stress was the only predictor for the placebo analgesic response. Contrary to our hypothesis, male subjects displayed increased placebo analgesia when a male acted as experimenter. The results indicate that reduced negative emotional activation could be a mechanism in placebo analgesia and that experimenter gender is probably not systematically related to placebo analgesia. | 18,725,424 |
Persistence of posttraumatic stress symptoms 12 and 36 months after acute coronary syndrome. | To assess the prevalence and predictors of posttraumatic stress symptoms in patients at 12 and 36 months post hospital admission for an acute coronary syndrome (ACS). There is increasing recognition that posttraumatic stress may develop in the aftermath of an acute cardiac event. However, there has been little research on the longer-term prevalence of posttraumatic stress disorder (PTSD). Posttraumatic stress symptoms were assessed at 12 months in 213 patients with ACS and in 179 patients at 36 months. Predictor variables included clinical, demographic, and emotional factors measured during hospital admission. At 12 months post ACS, 26 (12.2%) patients qualified for a diagnosis of PTSD; 23 (12.8%) patients were identified with PTSD at 36 months. Posttraumatic symptoms at 12 months were associated with younger age, ethnic minority status, social deprivation, cardiac symptom recurrence, history of depression, depressed mood during admission, hostility, and Type D personality. In multiple regression, depressed mood during admission and recurrent cardiac symptoms were independent predictors of posttraumatic symptoms (R(2) = 0.507, p < .001). At 36 months, posttraumatic stress symptoms were independently predicted by posttraumatic symptom levels at 12 months and depressed mood during admission (R(2) = 0.635, p < .001). Posttraumatic stress symptoms persist for at least 3 years after an acute cardiac event. Early emotional responses are important in predicting longer-term posttraumatic stress. It is important to identify patients at risk for posttraumatic stress as they are more likely to experience reduced quality of life. | 18,725,431 |
Dominance of blaCTX-M within an Australian extended-spectrum beta-lactamase gene pool. | bla(CTX-M) genes, particularly bla(CTX-M-15), are the dominant extended-spectrum beta-lactamase (ESBL) genes among clinical isolates of Escherichia coli and Klebsiella pneumoniae in Sydney, Australia, where we also found one example of bla(CTX-M-62), encoding a novel enzyme conferring ceftazidime resistance. ESBL genes were present in diverse community isolates and in a variety of associated conjugative plasmids. | 18,725,449 |
Arterial calcification in race horses. | Calcification of large arteries has been sporadically reported in horses. The pathogenesis is still unknown, but recent studies in humans suggest that this is a regulated biomineralizing process. This study surveyed the prevalence, distribution, and severity of vascular calcification in Thoroughbred and Standardbred racehorses. Histopathologic, ultrastructural imaging, and energy dispersive X-ray elemental analyses were used to examine the lesions. Calcification of the tunica media, predominantly the pulmonary artery, was found in 82% of horses (83/101). Young adult horses (mean [SD] age in years, 4.44 +/- 2.17) of both breeds and sexes were similarly affected. Lesions appeared as white-to-yellowish, hard, and gritty plaques of variable size. On microscopic examination, elastic fibers within the tunica media were thinned, fragmented, and calcified, and surrounded by dense collagen matrix. Elemental analysis showed distinct peaks for calcium and phosphorus, consistent with hydroxyapatite mineral. The frequent occurrence of calcification in the tunica media of large pulmonary arteries of young racing horses indicates the need to investigate its pathogenesis and potential clinical implications. | 18,725,464 |
Systemic reactive angioendotheliomatosis-like syndrome in a steer presumed to be persistently infected with bovine viral diarrhea virus. | Unusual proliferative intravascular lesions were seen in multiple organs of a 2-year-old Corriente steer presumed to be persistently infected with bovine viral diarrhea virus (BVDV), based on widespread immunohistochemical detection of BVDV antigen. Proliferations of spindle cells, which were immunohistochemically positive for von Willebrand factor-related antigen, partially-to-completely occluded vessel lumens and were supported by cells that were immunohistochemically positive for smooth muscle actin. Distribution and character of the intraluminal proliferations are strikingly similar to those described in feline systemic reactive angioendotheliomatosis, a rare entity of unknown cause. The presence of occasional intravascular thrombi suggests that the proliferative vasculopathy was associated with an underlying thrombotic process with immunohistochemical similarities to thrombotic thrombocytopenic purpura of humans. Death of the steer was due to hemorrhage from a castration wound, which may indicate thrombocytopenia or platelet dysfunction. The role of persistent BVDV infection in the formation of the intravascular lesions is unknown. | 18,725,468 |
Ganglioneuroma of the brachial plexus in two cockatiels (Nymphicus hollandicus). | Ganglioneuroma involving the brachial plexus, paraspinal ganglia, and cervical-thoracic spinal cord was diagnosed in 2 adult cockatiels (Nymphicus hollandicus). Both birds had a chronic 1-year history of ataxia and perching difficulty. At necropsy, each bird had a unilateral, firm, gelatinous white to tan multilobular mass at the thoracic inlet expanding and partially obliterating the brachial plexus and cervical spinal cord. Histologically, the masses were characterized by a locally infiltrative neoplasm comprised of spindloid cells forming streams and sheets with interspersed distinct neuron cell bodies consistent with ganglion cells. The spindloid cell population was immunohistochemically positive for neurofilament protein in one of the birds. | 18,725,475 |
Dynamic mechanism for initiation of ventricular fibrillation in vivo. | Dynamically induced heterogeneities of repolarization may lead to wave-front destabilizations and initiation of ventricular fibrillation (VF). In a computer modeling study, we demonstrated that specific sequences of premature stimuli maximized dynamically induced spatial dispersion of refractoriness and predisposed the heart to the development of conduction block. The purpose of this study was to determine whether the computer model results pertained to the initiation of VF in dogs in vivo. Monophasic action potentials were recorded from right and left ventricular endocardium in anesthetized beagle dogs (n=11) in vivo. Restitution of action potential duration and conduction time and the effective refractory period after delivery of the basic stimulus (S(1)) and each of 3 premature stimuli (S(2), S(3), S(4)) were determined at baseline and during verapamil infusion. The effective refractory period data were used to determine the interstimulus intervals for a sequence of 4 premature stimuli (S(2)S(3)S(4)S(5)=CL(VF)) for which the computer model predicted maximal spatial dispersion of refractoriness. Delivery of CL(VF) was associated with discordant action potential duration alternans and induction of VF in all dogs. Verapamil decreased spatial dispersion of refractoriness by reducing action potential duration and conduction time restitution in a dose-dependent fashion, effects that were associated with reduced inducibility of VF with CL(VF). Maximizing dynamically induced spatial dispersion of repolarization appears to be an effective method for inducing VF. Reducing spatial dispersion of refractoriness by modulating restitution parameters can have an antifibrillatory effect in vivo. | 18,725,487 |
Identification of hydroxywarfarin binding site in human UDP glucuronosyltransferase 1a10: phenylalanine90 is crucial for the glucuronidation of 6- and 7-hydroxywarfarin but not 8-hydroxywarfarin. | Recent studies show that the extrahepatic human UDP-glucuronosyltransferase (UGT)1A10 is capable of phase II glucuronidation of several major cytochrome P450 metabolites of warfarin (i.e., 6-, 7-, and 8-hydroxywarfarin). This study expands on this finding by testing the hypothesis that the UGT1A10 F(90)-M(91)-V(92)-F(93) amino acid motif is important for proper recognition and conjugation of hydroxywarfarin derivatives. Site-directed mutagenesis studies demonstrate that F(90) is critical for 6- and 7-hydroxywarfarin glucuronidation based on the complete loss of enzymatic activity toward these substrates. In contrast, V92A and F93A mutants lead to higher rates of substrate turnover, have minimum changes in K(m) values, and demonstrate substrate inhibition kinetics. A completely different activity profile is observed in the presence of 8-hydroxywarfarin. No change in either activity or affinity is observed with F90A when compared with wild type, whereas F93A and V92A mutants show increases in V(max) (3- and 10-fold, respectively) and minimum changes in K(m). Liquid chromatographytandem mass spectrometry studies show that enzymatic products produced by mutants are identical to wild-type products produced in the presence of 6-, 7-, and 8-hydroxywarfarin. Because F(90) is not critical for the glucuronidation of 8-hydroxywarfarin, there is likely another, different amino acid responsible for binding this compound. In addition, an inhibitory binding site may be formed in the presence of 6- and 7-hydroxywarfarin. This new knowledge and continued characterization of the hydroxywarfarin binding site(s) for UGT1A10 will help elucidate the molecular mechanism of hydroxywarfarin glucuronidation and potentially result in more effective anticoagulant therapies. | 18,725,508 |
A crucial role for hnRNP K in axon development in Xenopus laevis. | We report that hnRNP K, an RNA-binding protein implicated in multiple aspects of post-transcriptional gene control, is essential for axon outgrowth in Xenopus. Its intracellular localization was found to be consistent with one of its known roles as an mRNA shuttling protein. In early embryos, it was primarily nuclear, whereas later it occupied both the nucleus and cytoplasm to varying degrees in different neuronal subtypes. Antisense hnRNP K morpholino oligonucleotides (MOs) microinjected into blastomeres suppressed hnRNP K expression from neural plate stages through to at least stage 40. Differentiating neural cells in these embryos expressed several markers for terminally differentiated neurons but failed to make axons. Rescue experiments and the use of two separate hnRNP K MOs were carried out to confirm that these effects were specifically caused by knockdown of hnRNP K expression. For insights into the involvement of hnRNP K in neuronal post-transcriptional gene control at the molecular level, we compared effects on expression of the medium neurofilament protein (NF-M), the RNA for which binds hnRNP K, with that of peripherin, another intermediate filament protein, the RNA for which does not bind hnRNP K. hnRNP K knockdown compromised NF-M mRNA nucleocytoplasmic export and translation, but had no effect on peripherin. Because eliminating NF-M from Xenopus axons attenuates, but does not abolish, their outgrowth, hnRNP K must target additional RNAs needed for axon development. Our study supports the idea that translation of at least a subset of RNAs involved in axon development is controlled by post-transcriptional regulatory modules that have hnRNP K as an essential element. | 18,725,517 |
Toll-like receptor and IL-12 signaling control susceptibility to contact hypersensitivity. | Allergic contact hypersensitivity (CHS) is a T cell-mediated inflammatory skin disease. Interleukin (IL)-12 is considered to be important in the generation of the allergen-specific T cell response. Loss of IL-12 function in IL-12Rbeta2-deficient mice, however, did not ameliorate the allergic immune response, suggesting alternate IL-12-independent pathways in the induction of CHS. Because exposure to contact allergens always takes place in the presence of microbial skin flora, we investigated the potential role of Toll-like receptors (TLRs) in the induction of CHS. Using mice deficient in TLR4, the receptor for bacterial lipopolysaccharide (LPS), IL-12 receptor (R) beta2, or both, we show that the concomitant absence of TLR4 and IL-12Rbeta2, but not the absence of TLR4 or IL-12Rbeta2 alone, prevented DC-mediated sensitization, generation of effector T cells, and the subsequent CHS response to 2,4,6-trinitro-1-chlorobenzene (TNCB), oxazolone, and fluorescein isothiocyanate. Introduction of the TLR4 transgene into the TLR4/IL-12Rbeta2 mutant restored the CHS inducibility, showing a requirement for TLR4 in IL-12-independent CHS induction. Furthermore, the concomitant absence of TLR2 and TLR4 prevented the induction of CHS to TNCB in IL-12-competent mice. Finally, CHS was inducible in germ-free wild-type and IL-12Rbeta2-deficient mice, but not in germ-free TLR4/IL-12Rbeta2 double deficient mice, suggesting that the necessary TLR activation may proceed via endogenous ligands. | 18,725,520 |
Phosphorylation of the Arp2/3 complex is necessary to nucleate actin filaments. | The actin-related protein 2/3 (Arp2/3) complex is the primary nucleator of new actin filaments in most crawling cells. Nucleation-promoting factors (NPFs) of the Wiskott-Aldrich syndrome protein (WASP)/Scar family are the currently recognized activators of the Arp2/3 complex. We now report that the Arp2/3 complex must be phosphorylated on either threonine or tyrosine residues to be activated by NPFs. Phosphorylation of the Arp2/3 complex is not necessary to bind NPFs or the sides of actin filaments but is critical for binding the pointed end of actin filaments and nucleating actin filaments. Mass spectrometry revealed phosphorylated Thr237 and Thr238 in Arp2, which are evolutionarily conserved residues. In cells, phosphorylation of only the Arp2 subunit increases in response to growth factors, and alanine substitutions of Arp2 T237 and T238 or Y202 inhibits membrane protrusion. These findings reveal an additional level of regulation of actin filament assembly independent of WASP proteins, and show that phosphorylation of the Arp2/3 complex provides a logical "or gate" capable integrating diverse upstream signals. | 18,725,535 |
Autophagosome formation from membrane compartments enriched in phosphatidylinositol 3-phosphate and dynamically connected to the endoplasmic reticulum. | Autophagy is the engulfment of cytosol and organelles by double-membrane vesicles termed autophagosomes. Autophagosome formation is known to require phosphatidylinositol 3-phosphate (PI(3)P) and occurs near the endoplasmic reticulum (ER), but the exact mechanisms are unknown. We show that double FYVE domain-containing protein 1, a PI(3)P-binding protein with unusual localization on ER and Golgi membranes, translocates in response to amino acid starvation to a punctate compartment partially colocalized with autophagosomal proteins. Translocation is dependent on Vps34 and beclin function. Other PI(3)P-binding probes targeted to the ER show the same starvation-induced translocation that is dependent on PI(3)P formation and recognition. Live imaging experiments show that this punctate compartment forms near Vps34-containing vesicles, is in dynamic equilibrium with the ER, and provides a membrane platform for accumulation of autophagosomal proteins, expansion of autophagosomal membranes, and emergence of fully formed autophagosomes. This PI(3)P-enriched compartment may be involved in autophagosome biogenesis. Its dynamic relationship with the ER is consistent with the idea that the ER may provide important components for autophagosome formation. | 18,725,538 |
SopB promotes phosphatidylinositol 3-phosphate formation on Salmonella vacuoles by recruiting Rab5 and Vps34. | Salmonella colonizes a vacuolar niche in host cells during infection. Maturation of the Salmonella-containing vacuole (SCV) involves the formation of phosphatidylinositol 3-phosphate (PI(3)P) on its outer leaflet. SopB, a bacterial virulence factor with phosphoinositide phosphatase activity, was proposed to generate PI(3)P by dephosphorylating PI(3,4)P2, PI(3,5)P2, and PI(3,4,5)P3. Here, we examine the mechanism of PI(3)P formation during Salmonella infection. SopB is required to form PI(3,4)P2/PI(3,4,5)P3 at invasion ruffles and PI(3)P on nascent SCVs. However, we uncouple these events experimentally and reveal that SopB does not dephosphorylate PI(3,4)P2/PI(3,4,5)P3 to produce PI(3)P. Instead, the phosphatase activity of SopB is required for Rab5 recruitment to the SCV. Vps34, a PI3-kinase that associates with active Rab5, is responsible for PI(3)P formation on SCVs. Therefore, SopB mediates PI(3)P production on the SCV indirectly through recruitment of Rab5 and its effector Vps34. These findings reveal a link between phosphoinositide phosphatase activity and the recruitment of Rab5 to phagosomes. | 18,725,540 |
uPAR promotes formation of the p130Cas-Crk complex to activate Rac through DOCK180. | The urokinase-type plasminogen activator receptor (uPAR) drives tumor cell membrane protrusion and motility through activation of Rac; however, the pathway leading from uPAR to Rac activation has not been described. In this study we identify DOCK180 as the guanine nucleotide exchange factor acting downstream of uPAR. We show that uPAR cooperates with integrin complexes containing beta(3) integrin to drive formation of the p130Cas-CrkII signaling complex and activation of Rac, resulting in a Rac-driven elongated-mesenchymal morphology, cell motility, and invasion. Our findings identify a signaling pathway underlying the morphological changes and increased cell motility associated with uPAR expression. | 18,725,541 |
Condom 'turn offs' among adults: an exploratory study. | An exploratory study compared the prevalence of multiple types of condom-associated 'turn offs' in men and women. Nearly 2000 people completed a web-based questionnaire. Data were analysed from 464 men and women who reported that condoms had turned them off the last time they were used. Gender differences were not observed for the majority (9) of 15 turn offs. The most common turn offs related to loss of pleasure. For example, more than three-quarters of the men and nearly 40% of the women reported decreased sexual sensation (P = 0.0001). Putting on condoms was reported by 43.2% of the men versus 30.2% of the women (P = 0.02). Smell was a relatively frequent turn off, with about one-third indicating this issue and no significant gender difference (P = 0.32). Turn offs pertaining to arousal and orgasm were also common. Findings suggest that numerous physical and psychological condom turn offs may be experienced by men and women while using male condoms. Although some turn offs differed as a function of gender, there was remarkable similarity between men and women. | 18,725,548 |
Cognitive assessment and quantitative magnetic resonance metrics can help to identify benign multiple sclerosis. | The definition of benign multiple sclerosis (B-MS) is still controversial. This mainly takes into account the subject's motor ability, with little or no relevance to other important features such as cognition. Moreover, no paraclinical markers are currently available to reliably identify patients who will remain benign in the long term. To assess, by using quantitative magnetic resonance (MR) metrics, differences in tissue damage between B-MS patients after dividing them into two groups on the basis of their cognitive performance. Forty-seven B-MS patients (Expanded Disability Status Scale score </=3.0 and disease duration >/=15 years) underwent neuropsychological assessment through the Rao Brief Repeatable Battery and the Stroop Test. At that time, B-MS patients underwent conventional brain MR and magnetization transfer (MT) imaging. White matter lesion load, global and regional brain volumes, and MT ratio (MTr) in lesions and normal-appearing brain were measured. Quantitative MR measures were compared in cognitively impaired (CI-MS) and cognitively preserved (CP-MS) patients and in 24 demographically matched healthy controls. Test performance was correlated with MR changes in specific cortical regions. Eleven patients were classified as CI-MS, and 36 were classified as CP-MS. Both T2-weighted and T1-weighted lesion loads were higher (p = 0.05 and 0.001) in CI-MS than in CP-MS patients. Furthermore, CI-MS patients were characterized by more pronounced decrease in neocortical volume (p = 0.005) and cortical MTr (p = 0.02) values than CP-MS patients. Finally, test performance correlated significantly with MR changes in relevant cortical regions. Cognitive assessment and quantitative magnetic resonance can help to reliably identify benign multiple sclerosis patients. | 18,725,589 |
Natural history of SMA IIIb: muscle strength decreases in a predictable sequence and magnitude. | To assess the natural progression of muscle weakness in spinal muscular atrophy (SMA) IIIb. Ten patients with SMA IIIb were followed for at least 10 years. Age at disease onset varied between 9 and 18 years. Patients were initially seen 2 to 10 years after disease onset. They were evaluated at approximately 2, 5, 10, 15, and 20 years of disease duration depending on the timing of their initial visit after onset. Medical Research Council (MRC) scale was used with particular attention to proximal muscles. The MRC grade declined with years in all of the muscles. The decline was usually not more than by one MRC grade for each 5-year period. There were 5-10 year periods when some muscles appeared to remain stationary. The succession of weakness was first triceps, then biceps and deltoid for upper extremity muscles and first thigh adductors, then iliopsoas, then quadriceps femoris, then hamstrings, thigh abductors, and gluteus maximus for lower extremity muscles. There was a remarkable uniformity between patients in the MRC grade for each muscle at each stage: in the first 5 years of the disease, triceps, iliopsoas, thigh adductors, and quadriceps femoris were the muscles which had noticeable weakness. These findings show that strength in spinal muscular atrophy IIIb decreases over time, explaining the progressive functional loss. The sequence of weakness in the lower extremities suggests that the disease starts segmentally involving the upper lumbar segments of the medulla spinalis initially. The slowness of the deterioration may have implications for clinical trials. | 18,725,590 |
Second consensus statement on the diagnosis of multiple system atrophy. | A consensus conference on multiple system atrophy (MSA) in 1998 established criteria for diagnosis that have been accepted widely. Since then, clinical, laboratory, neuropathologic, and imaging studies have advanced the field, requiring a fresh evaluation of diagnostic criteria. We held a second consensus conference in 2007 and present the results here. Experts in the clinical, neuropathologic, and imaging aspects of MSA were invited to participate in a 2-day consensus conference. Participants were divided into five groups, consisting of specialists in the parkinsonian, cerebellar, autonomic, neuropathologic, and imaging aspects of the disorder. Each group independently wrote diagnostic criteria for its area of expertise in advance of the meeting. These criteria were discussed and reconciled during the meeting using consensus methodology. The new criteria retain the diagnostic categories of MSA with predominant parkinsonism and MSA with predominant cerebellar ataxia to designate the predominant motor features and also retain the designations of definite, probable, and possible MSA. Definite MSA requires neuropathologic demonstration of CNS alpha-synuclein-positive glial cytoplasmic inclusions with neurodegenerative changes in striatonigral or olivopontocerebellar structures. Probable MSA requires a sporadic, progressive adult-onset disorder including rigorously defined autonomic failure and poorly levodopa-responsive parkinsonism or cerebellar ataxia. Possible MSA requires a sporadic, progressive adult-onset disease including parkinsonism or cerebellar ataxia and at least one feature suggesting autonomic dysfunction plus one other feature that may be a clinical or a neuroimaging abnormality. These new criteria have simplified the previous criteria, have incorporated current knowledge, and are expected to enhance future assessments of the disease. | 18,725,592 |
Inhibition of the fungal fatty acid synthase type I multienzyme complex. | Fatty acids are among the major building blocks of living cells, making lipid biosynthesis a potent target for compounds with antibiotic or antineoplastic properties. We present the crystal structure of the 2.6-MDa Saccharomyces cerevisiae fatty acid synthase (FAS) multienzyme in complex with the antibiotic cerulenin, representing, to our knowledge, the first structure of an inhibited fatty acid megasynthase. Cerulenin attacks the FAS ketoacyl synthase (KS) domain, forming a covalent bond to the active site cysteine C1305. The inhibitor binding causes two significant conformational changes of the enzyme. First, phenylalanine F1646, shielding the active site, flips and allows access to the nucleophilic cysteine. Second, methionine M1251, placed in the center of the acyl-binding tunnel, rotates and unlocks the inner part of the fatty acid binding cavity. The importance of the rotational movement of the gatekeeping M1251 side chain is reflected by the cerulenin resistance and the changed product spectrum reported for S. cerevisiae strains mutated in the adjacent glycine G1250. Platensimycin and thiolactomycin are two other potent inhibitors of KSs. However, in contrast to cerulenin, they show selectivity toward the prokaryotic FAS system. Because the flipped F1646 characterizes the catalytic state accessible for platensimycin and thiolactomycin binding, we superimposed structures of inhibited bacterial enzymes onto the S. cerevisiae FAS model. Although almost all side chains involved in inhibitor binding are conserved in the FAS multienzyme, a different conformation of the loop K1413-K1423 of the KS domain might explain the observed low antifungal properties of platensimycin and thiolactomycin. | 18,725,634 |
Lignin degradation in wood-feeding insects. | The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of A. glabripennis identified a single species of fungus in the Fusarium solani/Nectria haematococca species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects. | 18,725,643 |
Twin hook fixation for proximal femoral fractures. | To report results of twin hook fixation for proximal femoral fractures in comparison to those fixed with the conventional lag screw. Between August 2005 and July 2006, 2 men and 15 women aged 74 to 94 (mean, 85) years with proximal femoral fractures underwent open reduction and internal fixation using the twin hook system. The tip-apex distance was compared with that in 20 patients treated with the sliding hip screw between August 2004 and July 2005. In the 17 patients, the hook was inserted into the centre of the femoral head. Bone union was achieved and no intra- or post-operative cut-out or device failure was encountered. In patients using the twin hook and sliding hip screw respectively, the mean tip-apex distance was 22.3 mm and 14.6 mm (p<0.001). Using the twin hook system requires more surgical skill than using the sliding hip screw, because failure to insert the pin into the centre of the femoral head risks intra-articular perforation by the hooks. | 18,725,664 |
Osteosynthesis for a T-shaped fracture of the femoral neck and trochanter: a case report. | Ipsilateral fractures of the femoral neck and trochanter are uncommon. We report a 30-year-old man with a T-shaped fracture separating the trochanter and neck from the head. He underwent osteosynthesis using a dynamic compression plate, screws, and pins. Bone union occurred 4 months postoperatively. At the one-year follow-up, the patient was free of pain and had no evidence of avascular necrosis. It is important to preserve the femoral head in young patients by preventing further compromise of the tenuous blood supply. | 18,725,685 |
Surgical wound mucormycosis necessitating hand amputation: a case report. | We report an unusual case of cutaneous mucormycosis in a 17-year-old man who had no risk factors for fungal infection. The aggressive nature of cutaneous mucormycosis is illustrated. A high index of suspicion is crucial for identifying and preventing progression of this disease, which can lead to limb amputation, even death. Extra vigilance should be given to those who are immunocompromised, including those receiving short courses of steroids. Early recognition, prompt surgical intervention and initiation of an appropriate antifungal treatment are crucial in the management of this rare but potentially limb- and life-threatening infection. | 18,725,688 |
Carrying loads and postural sway in standing: the effect of load placement and magnitude. | This study investigated the effect that load magnitude, load location, and the dimensions that the base of support have on postural sway in standing while wearing a backpack, single strapped bag, briefcase, or purse. Subjects were instructed to carry a load of 10% or 20% of their body weight with either their feet spaced shoulder width apart or together for a period of 45 seconds. Medial/lateral and anterior/posterior center of pressure (COP) displacement and COP velocity were calculated. Overall, it was found that an increase in load magnitude produced an increase in postural sway and velocity of COP. In addition, a large increase in the medial/lateral COP velocity was observed when subjects carried a briefcase, single strapped bag, or purse. Additionally, a larger COP sway was recorded in conditions of standing with decreased base of support (feet together). These findings suggest the importance of considering the way we carry loads in order not only to place less strain on the body and to minimize our efforts, but to optimize postural control as well. | 18,725,699 |
Which work factors determine job satisfaction? | Job satisfaction is associated with mental health. Employees could be counselled on how they feel about their work. If specific aspects of their job are causing particular dissatisfaction, they could be assisted to appropriately change these aspects. There is no 'gold standard' indicating the aspects that should be taken into account when job satisfaction is measured. This study investigated which work factors determine job satisfaction. A self-report questionnaire was sent to a random sample of 822 out of 1908 active employees. The questionnaire examined overall job satisfaction as well as satisfaction with specific work aspects using valid single-item measures. The response rate was 63%. Overall job satisfaction was 5.3 +/- 1.3 on a Likert-scale ranging from 1 (strongly disagree) to 7 (strongly agree). The work factors explained 54% of the variance in job satisfaction. Specific satisfaction with task variety, colleagues, working conditions, and workload were positively related to overall job satisfaction, as were career perspectives and job autonomy. Task variety, working conditions, workload, and career perspectives determine the greater part of job satisfaction. An instrument including these factors would provide beneficial information beyond current measures of job satisfaction. | 18,725,706 |
Marine macroalga Sargassum horneri as biosorbent for heavy metal removal: roles of calcium in ion exchange mechanism. | Brown seaweed Sargassum horneri, a troublesome biomass scattered along the seashore, was utilized as a biosorbent for Pb(II) removal from aqueous solutions. The Pb(II) adsorption by brown seaweed was enhanced by pretreatment with CaCl(2), and the Langmuir adsorption isotherm equation showed a maximum capacity of a Q(max) of 0.696 mmol/g and a b value of 94.33 L/mmol. Results obtained from the mass-balance equation derived from the simulation model of the Langmuir adsorption isotherm suggested that the adsorption performance of brown seaweed biosorbent was sufficient to reduce the concentration of Pb(II) to meet the range of WHO guideline. The mechanism, as elucidated using pH monitoring, adsorption rate and ion exchange model, involved the rapid pH change of metal solutions that led to high reaction rate and Pb(II) uptake in the first 30 min of the biosorption process. The energy X-ray analysis's result confirmed the sharp reduction of calcium content in the biosorbent after Pb(II) adsorption. The amount of calcium ions released from the biosorbent was about 1.5 times the amount of Pb(II) adsorbed and proved the role of calcium in the ion exchange mechanism. These adsorption equilibrium and mechanistic studies provide useful information for system design and performance prediction of biosorption processes. | 18,725,741 |
Arginine, nitric oxide, carbon monoxide, and endothelial function in severe malaria. | Parasiticidal therapy of severe falciparum malaria improves outcome, but up to 30% of these patients die despite best therapy. Nitric oxide is protective against severe disease, and both nitric oxide and arginine (the substrate for nitric oxide synthase) are low in clinical malaria. Parasitized red blood cell interactions with endothelium are important in the pathophysiology of malaria. This review describes new information regarding nitric oxide, arginine, carbon monoxide, and endothelial function in malaria. Low arginine, low nitric oxide production, and endothelial dysfunction are common in severe malaria. The degree of hypoargininemia and endothelial dysfunction (measured by reactive hyperemia-peripheral artery tonometry) is proportional to parasite burden and severity of illness. Plasma arginase (an enzyme that catabolizes arginine) is elevated in severe malaria. Administering arginine intravenously reverses hypoargininemia and endothelial dysfunction. The cause(s) of hypoargininemia in malaria is unknown. Carbon monoxide (which shares certain functional properties with nitric oxide) protects against cerebral malaria in mice. Replenishment of arginine and restoration of nitric oxide production in clinical malaria should diminish parasitized red blood cells adherence to endothelium and reduce the sequelae of these interactions (e.g. cerebral malaria). Arginine therapy given in addition to conventional antimalaria treatment may prove to be beneficial in severe malaria. | 18,725,795 |
Quality of life in patients with idiopathic sudden hearing loss: comparison of different therapies using the Medical Outcome Short Form (36) Health Survey questionnaire. | Cause and underlying pathogenic mechanisms of idiopathic sudden hearing loss (ISHL) are not fully understood, resulting in the widespread use of different polypragmatic treatment approaches, which have not been finally validated in randomized controlled trials. Quality of life (QoL) can provide helpful additional information when selecting the most appropriate therapy within current options. In a prospective, multicenter, randomized, controlled clinical study, Rheopheresis-a method of therapeutic apheresis-was compared with a standard therapy consisting of either intravenous corticosteroids or hemodilution using pure-tone and speech audiometry. Quality of life as secondary outcome parameter was documented using the German Medical Outcome Short Form (36) Health Survey questionnaire. Two hundred forty patients were included in this trial. All three treatment options proved to be of equal efficacy regarding absolute and relative hearing gain or speech discrimination. Quality of life measured in Medical Outcome Short Form (36) Health Survey scores was less than the level of the normal German population at baseline for all groups, and mentally, ISHL patients felt more impaired than patients who have chronic hearing impairment. Rheopheresis treatment led to a higher QoL at the time of the follow-up visit compared with the drug-based therapies and compared with a large representative sample of the German general population. Treatments leading to accelerated recovery in combination with a minimal number of therapeutic interventions, for example, Rheopheresis, seemed to have a considerable effect on QoL. Because there is a dearth of evidence of efficacy for any treatment option in ISHL, QoL can provide additional information when choosing the most appropriate treatment option. | 18,725,858 |
Urinary sucrose and fructose as biomarkers of sugar consumption: comparison of normal weight and obese volunteers. | Using urinary sugars as a biomarker of consumption, we have previously shown that obese people consume significantly more sugars than individuals of normal weight. However, there is concern that recovery of this biomarker may differ between normal weight and obese individuals. A total of 19 subjects, divided into two groups according to their body mass index (BMI) (normal weight BMI < or = 25 kg/m(2), n=10; obese BMI > or = 30 kg/m(2), n=9), participated in a randomized crossover dietary intervention study of three diets providing 13, 30 and 50% of energy from sugars for 4 days each while living in a volunteer suite. The mean urinary sucrose and fructose excretions in 24-h urine increased with increasing sugar consumption over the three dietary periods in both BMI groups and were significantly different between the diets (P < 0.01). There was no significant interaction effect of BMI class on the mean urinary excretions of these sugars with different sugar intakes, either as absolute values or expressed as a percentage of total sugar intake. In conclusion, BMI does not affect the validity of sucrose and fructose excretions in 24-h urine collections used as biomarkers to estimate total sugar consumption. | 18,725,895 |
Epigenetic control of myelin repair. | Although the CNS has a robust innate ability to repair demyelinated axons, this capacity appears to dissipate with age. A study in this issue suggests that epigenetic processes participate in myelin repair and that the epigenetic response is less dynamic in older individuals. | 18,725,899 |
Neuropeptide receptor transcriptome reveals unidentified neuroendocrine pathways. | Neuropeptides are an important class of molecules involved in diverse aspects of metazoan development and homeostasis. Insects are ideal model systems to investigate neuropeptide functions, and the major focus of insect neuropeptide research in the last decade has been on the identification of their receptors. Despite these vigorous efforts, receptors for some key neuropeptides in insect development such as prothoracicotropic hormone, eclosion hormone and allatotropin (AT), remain undefined. In this paper, we report the comprehensive cloning of neuropeptide G protein-coupled receptors from the silkworm, Bombyx mori, and systematic analyses of their expression. Based on the expression patterns of orphan receptors, we identified the long-sought receptor for AT, which is thought to stimulate juvenile hormone biosynthesis in the corpora allata (CA). Surprisingly, however, the AT receptor was not highly expressed in the CA, but instead was predominantly transcribed in the corpora cardiaca (CC), an organ adjacent to the CA. Indeed, by using a reverse-physiological approach, we purified and characterized novel allatoregulatory peptides produced in AT receptor-expressing CC cells, which may indirectly mediate AT activity on the CA. All of the above findings confirm the effectiveness of a systematic analysis of the receptor transcriptome, not only in characterizing orphan receptors, but also in identifying novel players and hidden mechanisms in important biological processes. This work illustrates how using a combinatorial approach employing bioinformatic, molecular, biochemical and physiological methods can help solve recalcitrant problems in neuropeptide research. | 18,725,956 |
The actin-binding protein capulet genetically interacts with the microtubule motor kinesin to maintain neuronal dendrite homeostasis. | Neurons require precise cytoskeletal regulation within neurites, containing microtubule tracks for cargo transport in axons and dendrites or within synapses containing organized actin. Due to the unique architecture and specialized function of neurons, neurons are particularly susceptible to perturbation of the cytoskeleton. Numerous actin-binding proteins help maintain proper cytoskeletal regulation. From a Drosophila forward genetic screen, we identified a mutation in capulet--encoding a conserved actin-binding protein--that causes abnormal aggregates of actin within dendrites. Through interaction studies, we demonstrate that simultaneous genetic inactivation of capulet and kinesin heavy chain, a microtubule motor protein, produces elongate cofilin-actin rods within dendrites but not axons. These rods resemble actin-rich structures induced in both mammalian neurodegenerative and Drosophila Alzheimer's models, but have not previously been identified by loss of function mutations in vivo. We further demonstrate that mitochondria, which are transported by Kinesin, have impaired distribution along dendrites in a capulet mutant. While Capulet and Cofilin may biochemically cooperate in certain circumstances, in neuronal dendrites they genetically antagonize each other. The present study is the first molecularly defined loss of function demonstration of actin-cofilin rods in vivo. This study suggests that simultaneous, seemingly minor perturbations in neuronal dendrites can synergize producing severe abnormalities affecting actin, microtubules and mitochondria/energy availability in dendrites. Additionally, as >90% of Alzheimer's and Parkinson's cases are sporadic this study suggests mechanisms by which multiple mutations together may contribute to neurodegeneration instead of reliance on single mutations to produce disease. | 18,725,959 |
Psychosocial Moderators the Effects of Transitioning Into Filial Caregiving on Mental and Physical Health. | A life-course theoretical perspective guided this study to examine how effects on mental and physical health (depressive symptoms, hostility, global happiness, self-esteem, personal mastery, psychological wellness, self-rated physical health) of transitioning into filial caregiving for a sole surviving parent are moderated by prior relationship quality, filial obligation, race or ethnicity, education, income, employment status, marital status, and parental status. Results from models estimated using longitudinal data from 1,060 adults aged 25 to 65 years at baseline (National Survey of Families and Households, 1987 to 1994) suggested that life-course and contextual factors do contribute to patterning health risks of caregiving, often in different ways for men and women: For example, low income puts daughter caregivers at greater risk for decline in physical health, combining employment with filial caregiving is more problematic for daughters' mental health, and being an unmarried filial caregiver is more problematic for men. Heterogeneity in the experience of filial care needs further attention in future research. | 18,725,964 |
Cre-dependent expression of multiple transgenes in isolated neurons of the adult forebrain. | Transgenic mice with mosaic, Golgi-staining-like expression of enhanced green fluorescent protein (EGFP) have been very useful in studying the dynamics of neuronal structure and function. In order to further investigate the molecular events regulating structural plasticity, it would be useful to express multiple proteins in the same sparse neurons, allowing co-expression of functional proteins or co-labeling of subcellular compartments with other fluorescent proteins. However, it has been difficult to obtain reproducible expression in the same subset of neurons for direct comparison of neurons expressing different functional proteins. Here we describe a Cre-transgenic line that allows reproducible expression of transgenic proteins of choice in a small number of neurons of the adult cortex, hippocampus, striatum, olfactory bulb, subiculum, hypothalamus, superior colliculus and amygdala. We show that using these Cre-transgenic mice, multiple Cre-dependent transgenes can be expressed together in the same isolated neurons. We also describe a Cre-dependent transgenic line expressing a membrane associated EGFP (EGFP-F). Crossed with the Cre-transgenic line, EGFP-F expression starts in the adolescent forebrain, is present in dendrites, dendritic protrusions, axons and boutons and is strong enough for acute or chronic in vivo imaging. This triple transgenic approach will aid the morphological and functional characterization of neurons in various Cre-dependent transgenic mice. | 18,725,976 |
PPARalpha Ligands as Antitumorigenic and Antiangiogenic Agents. | Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear receptor family of ligand-activated transcription factors. This subfamily is composed of three members-PPARalpha, PPARdelta, and PPARgamma-that differ in their cell and tissue distribution as well as in their target genes. PPARalpha is abundantly expressed in liver, brown adipose tissue, kidney, intestine, heart, and skeletal muscle; and its ligands have been used to treat diseases such as obesity and diabetes. The recent finding that members of the PPAR family, including the PPARalpha, are expressed by tumor and endothelial cells together with the observation that PPAR ligands regulate cell growth, survival, migration, and invasion, suggested that PPARs also play a role in cancer. In this review, we focus on the contribution of PPARalpha to tumor and endothelial cell functions and provide compelling evidence that PPARalpha can be viewed as a new class of ligand activated tumor "suppressor" gene with antiangiogenic and antitumorigenic activities. Given that PPAR ligands are currently used in medicine as hypolipidemic drugs with excellent tolerance and limited toxicity, PPARalpha activation might offer a novel and potentially low-toxic approach for the treatment of tumor-associated angiogenesis and cancer. | 18,725,983 |
Misfolded proteins activate factor XII in humans, leading to kallikrein formation without initiating coagulation. | When blood is exposed to negatively charged surface materials such as glass, an enzymatic cascade known as the contact system becomes activated. This cascade is initiated by autoactivation of Factor XII and leads to both coagulation (via Factor XI) and an inflammatory response (via the kallikrein-kinin system). However, while Factor XII is important for coagulation in vitro, it is not important for physiological hemostasis, so the physiological role of the contact system remains elusive. Using patient blood samples and isolated proteins, we identified a novel class of Factor XII activators. Factor XII was activated by misfolded protein aggregates that formed by denaturation or by surface adsorption, which specifically led to the activation of the kallikrein-kinin system without inducing coagulation. Consistent with this, we found that Factor XII, but not Factor XI, was activated and kallikrein was formed in blood from patients with systemic amyloidosis, a disease marked by the accumulation and deposition of misfolded plasma proteins. These results show that the kallikrein-kinin system can be activated by Factor XII, in a process separate from the coagulation cascade, and point to a protective role for Factor XII following activation by misfolded protein aggregates. | 18,725,990 |
Platelet glycoprotein Ibalpha forms catch bonds with human WT vWF but not with type 2B von Willebrand disease vWF. | Arterial blood flow enhances glycoprotein Ibalpha (GPIbalpha) binding to vWF, which initiates platelet adhesion to injured vessels. Mutations in the vWF A1 domain that cause type 2B von Willebrand disease (vWD) reduce the flow requirement for adhesion. Here we show that increasing force on GPIbalpha/vWF bonds first prolonged ("catch") and then shortened ("slip") bond lifetimes. Two type 2B vWD A1 domain mutants, R1306Q and R1450E, converted catch bonds to slip bonds by prolonging bond lifetimes at low forces. Steered molecular dynamics simulations of GPIbalpha dissociating from the A1 domain suggested mechanisms for catch bonds and their conversion by the A1 domain mutations. Catch bonds caused platelets and GPIbalpha-coated microspheres to roll more slowly on WT vWF and WT A1 domains as flow increased from suboptimal levels, explaining flow-enhanced rolling. Longer bond lifetimes at low forces eliminated the flow requirement for rolling on R1306Q and R1450E mutant A1 domains. Flowing platelets agglutinated with microspheres bearing R1306Q or R1450E mutant A1 domains, but not WT A1 domains. Therefore, catch bonds may prevent vWF multimers from agglutinating platelets. A disintegrin and metalloproteinase with a thrombospondin type 1 motif-13 (ADAMTS-13) reduced platelet agglutination with microspheres bearing a tridomain A1A2A3 vWF fragment with the R1450E mutation in a shear-dependent manner. We conclude that in type 2B vWD, prolonged lifetimes of vWF bonds with GPIbalpha on circulating platelets may allow ADAMTS-13 to deplete large vWF multimers, causing bleeding. | 18,725,999 |
Transcription monitoring using fused RNA with a dye-binding light-up aptamer as a tag: a blue fluorescent RNA. | The "light-up" RNA aptamer-Hoechst pair can be used as a fluorescent tag to monitor transcription processes. | 18,726,014 |
Giant molecular spoked wheels in giant voids: two-dimensional molecular self-assembly goes big. | We present here the formation of giant pores in surface-confined molecular networks of a triangular-shaped dehydrobenzo-[12]annulene derivative: the diameter of the pores reaches over 7 nm and the giant pores are used as templates to accommodate a giant molecular spoked wheel, which allows us to observe rotational and adsorption-desorption dynamics of single guest molecules. | 18,726,027 |
Manipulating the cavity of a porous material changes the photoreactivity of included guests. | Changing an ether to a ketone within the framework of a bis-urea macrocycle has little effect on the supramolecular assembly of this building block into porous crystals but introduces a triplet sensitizer into the framework that dramatically alters the photochemical reactions of included guests. | 18,726,031 |
A photosensitive {Ru-NO}6 nitrosyl bearing dansyl chromophore: novel NO donor with a fluorometric on/off switch. | The synthesis, fluorescence properties and NO photolability of [(Me(2)bpb)Ru(NO)(Ds-im)]BF(4), a {Ru-NO}(6) nitrosyl-fluorophore conjugate, have been investigated and its potential as a trackable NO donor has been evaluated. | 18,726,039 |
[Cognitive impairment in normal pressure hydrocephalus (NPH). A proposal for clinical evaluation protocol]. | Normal pressure hydrocephalus (NPH) is characterized by gait disturbance, urinary incontinence and dementia, and is associated with variable ventricular enlargement. The most accepted treatment of NPH is the placement of a cerebrospinal fluid shunt. Owing to the characteristics of the patients and the invasive nature of the surgical treatment, it is fundamental to detect those patients who could obtain a greater benefit from the treatment. Neuropsychological assessment of these patients could significantly contribute to a better diagnosis of NPH, determining a cognitive deterioration profile for these patients, allowing the assessment of treatment efficacy and helping to detect other additional causes of dementia. The aim of this study is to describe the cognitive deterioration profile of NPH patients and to present the clinical, functional and neuropsychological assessment protocol used in our hospital. | 18,726,041 |
[Spontaneous resolution of an asymptomatic intracranial arachnoid cyst]. | Arachnoid cysts are commonly considered to be benign, congenial, extraparenchymatous anomalies. Small cyst are common incidental findings in children and adults. The aetiology and natural history of arachnoid cysts are not fully understood. In most cases, the presence of the cysts is detected on CT-scans or MRI performed for other reasons. In the literature, there have been few documented cases of arachnoid cysts with spontaneous regression. We reports the case of a silvian arachnoid cyst, which disappeared spontaneously during the 13-year-follow-up period. We review the cases previously reported and the mechanisms underlying the resolution of the arachnoid cysts are discussed. | 18,726,048 |
A cystic amelanotic melanoma metastasis to the brain: case report. | As far as we know, cyst formation in intracranial melanoma is rare, and only 15 cases of intracranial amelanotic melanoma have been reported until now. A yellowish mass was observed in the frontal lobe. The content of the cyst consisted of old hematoma, xanthochromic fluid and necrotic tissue, was evacuated and the cyst wall was totally resected. No abnormal pigmentation was noted in the cyst wall and surrounding brain tissue. The imaging features of metastatic melanomas are distinctive due to the presence of melanin and the propensity for hemorrhage. Both hemorrhage and melanin can produce T1-weighted hyperintensity and T2-weighted signal intensity loss. | 18,726,049 |
Biodiversity offsets: two New Zealand case studies and an assessment framework. | Biodiversity offsets are increasingly being used for securing biodiversity conservation outcomes as part of sustainable economic development to compensate for the residual unavoidable impacts of projects. Two recent New Zealand examples of biodiversity offsets are reviewed-while both are positive for biodiversity conservation, the process by which they were developed and approved was based more on the precautionary principal than on any formal framework. Based on this review and the broader offset literature, an environmental framework for developing and approving biodiversity offsets, comprising six principles, is outlined: (1) biodiversity offsets should only be used as part of an hierarchy of actions that first seeks to avoid impacts and then minimizes the impacts that do occur; (2) a guarantee is provided that the offset proposed will occur; (3) biodiversity offsets are inappropriate for certain ecosystem (or habitat) types because of their rarity or the presence of threatened species within them; (4) offsets most often involve the creation of new habitat, but can include protection of existing habitat where there is currently no protection; (5) a clear currency is required that allows transparent quantification of values to be lost and gained in order to ensure ecological equivalency between cleared and offset areas; (6) offsets must take into account both the uncertainty involved in obtaining the desired outcome for the offset area and the time-lag that is involved in reaching that point. | 18,726,050 |
Adaptation as a political process: adjusting to drought and conflict in Kenya's drylands. | In this article, we argue that people's adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options and promote particular adaptation interests through forming social relations and political alliances to influence collective decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians, customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing material means of survival. Second, national economic and political structures and processes affect local adaptive capacity in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process, not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation, but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however, existing power structures and conflicts of interests represent political obstacles to developing such policies. | 18,726,051 |
Transport at the nanoscale: temperature dependence of ion conductance. | Temperature dependent ion conductance in nanopores is measured in a wide range of electrolyte concentrations and compared with molecular modeling. Single outer membrane protein F (OmpF) channels from E. coli are reconstituted into planar lipid bilayers. In qualitative agreement with the experimental data, applied-field molecular dynamics unraveled atomistic details of the ion transport. Comparing the temperature dependence of the channel conductance with that of the bulk conductivity in the range from 0 to 90 degrees C revealed that at low salt concentrations the transport is mainly driven along the pore surface. Increasing the salt concentration saturates the surface charge transport and induces ion transport in the center of the nanopore. The confinement of the nanopore then favors the formation of ion pairs. Stepping up the temperature reduces the life time of the ion pairs and increases the channel conductance more than expected from the bulk behavior. | 18,726,094 |
Fetal therapy in twin reserve arterial perfusion sequence pregnancies with alcohol ablation or bipolar cord coagulation. | We aimed to evaluate perinatal outcome of seven pregnancies with twin reserve arterial perfusion sequence. Study group included seven cases of acardiac twins. Out of seven acardiac twins, two cases were followed without interventions. We performed four alcohol ablation and one bipolar coagulation. For alcohol ablation, a 20-gauge needle guided with color Doppler USG was directed to abdominal insertion site of the single umbilical artery of the acardiac twin, and 1.0-2.0 mL of absolute alcohol was injected. For bipolar coagulation of the umbilical cord, we used 3.5 mm laparoscopic trocar and 3.0 mm bipolar forceps. The procedures were performed under the guidance of transabdominal ultrasonography. Gestational age of the cases at diagnosis and at delivery was 15-32 and 17-38 weeks, respectively. Two cases without intervention were lost at 17 and 32 weeks. The mean time of procedure for bipolar coagulation and alcohol ablation were 30 and 10 min, respectively. One of the four cases of alcohol ablation group was aborted although alcohol ablation was successful. Another one case was aborted after alcohol ablation due to lost of fetal cardiac activity of the pump fetus. In two other cases, umbilical cord ablation with alcohol was successful, and they delivered live birth at 36 and 38 weeks. In one case, we performed bipolar cord coagulation successfully, and the case delivered live birth at 39 weeks. The overall survival rate for intrauterine surgery was 60% (N 3/5). In twin reserve arterial perfusion sequence pregnancies with findings of poor prognosis, alcohol ablation or bipolar cord coagulation as fetal therapy under the guidance of ultrasonography can be done successfully, and should be offered as a choice to families upon discussion of intervention or follow-up with own complications. | 18,726,110 |
Physical activity, exercise, depression and anxiety disorders. | There is a general belief that physical activity and exercise have positive effects on mood and anxiety and a great number of studies describe an association of physical activity and general well-being, mood and anxiety. In line, intervention studies describe an anxiolytic and antidepressive activity of exercise in healthy subjects and patients. However, the majority of published studies have substantial methodological shortcomings. The aim of this paper is to critically review the currently available literature with respect to (1) the association of physical activity, exercise and the prevalence and incidence of depression and anxiety disorders and (2) the potential therapeutic activity of exercise training in patients with depression or anxiety disorders. Although the association of physical activity and the prevalence of mental disorders, including depression and anxiety disorders have been repeatedly described, only few studies examined the association of physical activity and mental disorders prospectively. Reduced incidence rates of depression and (some) anxiety disorders in exercising subjects raise the question whether exercise may be used in the prevention of some mental disorders. Besides case series and small uncontrolled studies, recent well controlled studies suggest that exercise training may be clinically effective, at least in major depression and panic disorder. Although, the evidence for positive effects of exercise and exercise training on depression and anxiety is growing, the clinical use, at least as an adjunct to established treatment approaches like psychotherapy or pharmacotherapy, is still at the beginning. Further studies on the clinical effects of exercise, interaction with standard treatment approaches and details on the optimal type, intensity, frequency and duration may further support the clinical administration in patients. Furthermore, there is a lack of knowledge on how to best deal with depression and anxiety related symptoms which hinder patients to participate and benefit from exercise training. | 18,726,137 |
Prediction of protein structural classes by Chou's pseudo amino acid composition: approached using continuous wavelet transform and principal component analysis. | A prior knowledge of protein structural classes can provide useful information about its overall structure, so it is very important for quick and accurate determination of protein structural class with computation method in protein science. One of the key for computation method is accurate protein sample representation. Here, based on the concept of Chou's pseudo-amino acid composition (AAC, Chou, Proteins: structure, function, and genetics, 43:246-255, 2001), a novel method of feature extraction that combined continuous wavelet transform (CWT) with principal component analysis (PCA) was introduced for the prediction of protein structural classes. Firstly, the digital signal was obtained by mapping each amino acid according to various physicochemical properties. Secondly, CWT was utilized to extract new feature vector based on wavelet power spectrum (WPS), which contains more abundant information of sequence order in frequency domain and time domain, and PCA was then used to reorganize the feature vector to decrease information redundancy and computational complexity. Finally, a pseudo-amino acid composition feature vector was further formed to represent primary sequence by coupling AAC vector with a set of new feature vector of WPS in an orthogonal space by PCA. As a showcase, the rigorous jackknife cross-validation test was performed on the working datasets. The results indicated that prediction quality has been improved, and the current approach of protein representation may serve as a useful complementary vehicle in classifying other attributes of proteins, such as enzyme family class, subcellular localization, membrane protein types and protein secondary structure, etc. | 18,726,140 |
Phosphoinositides as regulators of membrane trafficking in health and disease. | Membrane trafficking is crucial in the homeostasis of the highly compartmentalized eukaryotic cells. This compartmentalization occurs both at the organelle level, with distinct organelles maintaining their identities while also intensely interchanging components, and at a sub-organelle level, with adjacent subdomains of the same organelle containing different sets of lipids and proteins. A central question in the field is thus how this compartmentalization is established and maintained despite the intense exchange of components and even physical continuities within the same organelle. The phosphorylated derivatives of phosphatidylinositol, known as the phosphoinositides, have emerged as key components in this context, both as regulators of membrane trafficking and as finely tuned spatial and temporal landmarks for organelle and sub-organelle domains. The central role of the phosphoinositides in cell homeostasis is highlighted by the severe consequences of the derangement of their metabolism caused by genetic deficiencies of the enzymes involved, and from the systematic hijacking of phosphoinositide metabolism that pathogens operate to promote their entry and/or survival in host cells. | 18,726,176 |
Membrane traffic in the secretory pathway. | During the last 20 years remarkable achievements have been made in the understanding of the molecular basis of membrane traffic in the secretory pathway. A combination of morphological, biochemical and genetical approaches revealed the identity of various compartments and transport intermediates, and provided basic functional insights into membrane trafficking. Recently, live cell imaging approaches further refined our understanding of the underlying mechanisms of budding, transport and fusion of transport containers, led to the discovery of new pathways and triggered new concepts as to how membrane traffic is orchestrated. This multi-author review highlights recent advances in membrane traffic by focusing on transport vesicles as the central mediators of communication in the secretory pathway. | 18,726,181 |
Possibility of biological micromachining used for metal removal. | Besides the physical and chemical machining methods, a biological machining method has been presented. The experimental results show that machining of pure iron, pure copper and constantan by a special bacterium,Thiobacillus ferrooxidans, was possible. A micro gear and grooves on pure copper piece were bio-machined. The depth of the groove so bio-machined was directly dependent on the machining time. The biomachining mechanism has been analyzed from the electron-transport chain (ETC) in the T.ferrooxidans membrane, and its developing direction has been also discussed. | 18,726,199 |
Monoclonal antibody, a novel probe for protein folding. | Two monoclonal antibodies (McAb2C9, McAb1E5) against Staphylococcal nuclease R (SNase R) and its N-terminal peptide fragments were prepared, purified and characterized. Further studies show that the intact enzyme SNase R and its seven N-terminal peptide fragments differ in their interaction with McAb2C9. SNase R, SNR121, SNR102, SNR79 and SNR52 can bind to McAb2C9 readily, while fragments of SNR141, SNR135, SNR110 react with the antibody poorly. If this difference is due to diverse extent of exposure of the specific epitope in the fragments, it is suggested that the conformation of the peptide is subjected to continuous adjustments through chain elongation until the biologically active protein is formed. This result supports Tsou's hypothesis of nascent peptide folding experimentally. | 18,726,201 |
Membrane molecules in induction of apoptosis of thymocytes by mouse thymic dendritic cells which express Fas ligands. | Apoptosis of thymocytes is involved in the negative selection of thymus, but it remains unclear how the cell death of thymocytes is regulated by the thymic stromal cells. By using immunohistochemistry, TdT-mediated dUTP nick end labeling (TUNEL) and flow cytometry methods, it was found that Fas ligand was expressed in the thymic medulla and a mouse thymic medullary type dendritic cell line (MTSC4). The DNA fragmentation and TUNEL positive staining of thymocytes were detected in 6 h of cocultures with MTSC4. 97 % of the thymocytes which bound to MTSC4 were Fas antigen positive cells. The DNA fragmentation of thymocytes induced by MTSC4 was inhibited by the addition of 20 mmol/L N-acetyl galactosamin monosaccharide and the pretreatment of a monoclonal antibody (PF-18-3) which recognized a putative antigen on MTSC4. These results suggested that the mechanisms of induction of cell death by stromal cells may include the interactions of multiple cell surface molecules, in addition to the Fas/Fas ligand system. | 18,726,205 |
Isolation and partial molecular characterization of heat-stable growth factor from human placenta. | A heat-stable growth factor has been purified to homogeneity from human placenta. Purification procedure involved extraction with acidic medium, precipitation using ethanol, DE-52 ion-exchange chromatography, and reversed-phase HPLC. The purified preparation has been named human placental growth factor-1 (HPGF-1), which simulates the proliferation of some cell lines, such as human amniotic cell, mouse marrow tumor cell, and mouse fibroblast cell. The growth factor has an approximate molecular weight of 1 900. It is a glycopeptide which contains a polypeptide chain consisting of 10 amino acid residues with molecular weight of 1 195. The N-terminal residue of the polypeptide chain part is phenylalanine. The molecular weight of non-peptide part is 682. The isoelectric point of the growth factor is pI 6.8. | 18,726,219 |
Raman spectroscopic study of DNA after photosensitive damage caused by hypocrellins A and B. | Laser Raman spectroscopy provided the direct evidence for microcosmic photodamage in space structure of DNA molecule. When photosensitive damage was made to space structure of calf thymus DNA by hypocrellins A and B. the Raman characteristic frequencies and the intensities of the bands assigned to various groups of the components of DNA (phosphate backbone dsoxyribose and four bases) changed at various degrees. There were not only the strsnd breakage, but also the breakage of some H-bonds and disruption of vertical base-base stacking interactions. The photosensitive damage of hypocrellin B on DNA was stronger than that of hypocrellin A on DNA. | 18,726,251 |
Expression and regulation of hFIX minigene and cDNA driven by beta-casein gene in mouse mammary gland. | Mammary gland specific expression vectors for human clotting factor IX (hFIX) and LacZ reporter gene driven by bovine beta-casein gene were constructed. Vectors were packaged by stearylamine (SA) liposome and were transferred to lactating mice via tail vein. Both hFIX and Lac2 gene could be expressed in the mammary gland of the treated mice. The highest production of hFIX protein was 80.28 ng per mL milk, and more than 85% of hFIX protein appeared to be gamma-carboxylation and biologically active. The results suggested that the 2.0 kb sequence of beta-casein gene including promoter, exon 1 was effective to drive hFIX gene expression in mammary gland and intron 1 of beta-casein gene had an effect on the tissue specific expression. The expression level in mouse milk injected with hFIX minigene vector containing hFIX endogenous intron 1 was increased by above 3 times of that injected with hFIX cDNA vector. | 18,726,258 |
Spatiotemporal organization of simple-cell receptive fields in area 18 of cat's cortex. | Spatiotemporal structures of receptive-fields (RF) have been studied for simple cells in area 18 of eat by measuring the temporal transfer function (TTF) over different locations (subregions) within the RF. The temporal characteristics of different subregions differed from each other in the absolute phase shift (APS) to visual stimuli. Two types of relationships can be seen: (i)The APS varied continuously from one subregion to the next: (ii) A 180 degrees -phase jump was seen as the stimulus position changed somewhere within the receptive field. Spatiotemporal receptive field profiles have been determined by applying reverse Fourier analysis to responses in the frequency domain. For the continuous type, spatial and temporal characteristics cannot be dissociated (space time inseparable) and the spatiotemporal structure is oriented. On the contrary, the spatial and temporal characteristics for the jumping type can be dissociated (space-time separable) and the structure is not oriented in the space-time plane. Based on the APSs measured at different subregions, the optimal direction of motion and optimal spatial frequency of neurons can be predicted. | 18,726,264 |
Isolation, properties and spatial site analysis of gamma subunits of B-phycoerythrin and R-phycoerythrin. | Polysiphonia urceolata R-phycoerythrin and Porphyridium cruentum B-phycoerythrin were degraded with proteinaseK, and then the nearly native gamma subunits were isolated from the reaction mixture. The process of degradation of phycoerythrin with proteinaseK showed that the gamma subunit is located in the central cavity of (alphabeta)(6) hexamer of phycoerythrin. Comparative analysis of the spectra of the native phycoerythrin, the phycoerythrin at pH 12 and the isolated gamma subunit showed that the absorption peaks of phycoerythrobilins on alpha or beta subunit are at 535 nm (or 545 nm) and 565 nm, the fluorescence emission maximum at 580 nm; the absorption peak of phycoerythrobilins on the isolated gamma subunit is at 589 nm, the fluorescence emission peak at 620 nm which overlaps the absorption maximum of C-phycocyanin and perhaps contributes to the energy transfer with high efficiency between phycoerythrin and phycocyanin in phycobilisome; the absorption maximum of phycourobilin on the isolated gamma subunit is at 498 nm, which is the same as that in native phycoerythrin, and the fluorescence emission maximum at 575 nm. | 18,726,265 |
A modified hepatitis B surface antigen carrying both preS1 and preS2 epitopes. | The DNA fragments coding for preS2(120-146) and preS1(21-47) amplified by PCR were fused to both 5' and 3' ends of S gene at the position of amino acid 223. The fusion gene was placed downstream of the promoter P7.5 of the universal vaccinia viral vector pGJP-5 and the recombinant vaccinia virus vS2SSI was then selected by invivo homogeneous recombination. Fusion protein S2SS1 could be expressed in the mammalian cells infected with vS2SSl. The investigation of expression, secretion, antigenicity and particle assembly of the S2SS1 protein demonstrated that S2SS1 protein could be assembled into particles which presented preSl, preS2 and S antigenicity and be efficiently secreted from the cells. It also showed that the level of its expression and secretion approached to that of the S protein expressed by the recombinant vaccinia virus. | 18,726,271 |
Fine structure and assembly in vitro of nuclear lamina in plant cells. | The fine structure of the nuclear lamina (NL) in sperm cells of Ginkgo biloba was visualised using high resolution low-voltage scanning electron microscopy (LVSEM). It was shown that the nuclear lamina was composed of 10 nm filaments which formed a fine network. Lamins were purified from cultured carrot suspension cells and assembled in vitro. Long 8-12 nm diameter filaments were seen and sometimes subfilaments could be distinguished. Western blot of filament preparations showed that these contained the 66 and 84 ku lamins. These data demonstrate that plant lamins are capable of assembling into filaments in vitro. | 18,726,273 |
Immunomodulated signaling in macrophages: Studies on activation of Raf-1, MAPK, cPLA(2) and secretion of IL-12. | Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA(2) is activated with a significant increase of the release of [ H(3) ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-alpha and PKC-epsilon, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages. | 18,726,282 |
Effect of lysophosphatidylcholine on behavior and structure of phosphatidylcholine liposomes. | Differential scanning calorimetry (DSC), fluorescence polarization and X-ray diffraction were performed to investigate the kinetics of the micellar to the lamellar phase transition of dipalmitoylphosphatidylcholine/1-palmitoylphosphatidylcholine (16:0 LPC/DPPC) liposomes at gel phase. With a 16:0 LPC concentration up to 27 mol% only the sharp main transition with relatively high enthalpy (DeltaH) values of DPPC was observed. Increasing 16 : 0 LPC concentration, the phase transition was broadened and the transition enthalpy was decreased and finally totally disappeared. The fluorescence probes of 3AS, 9AS, 12AS, and 16AP were employed, respectively, to detect the mobility of various sites of carbon chains of DPPC or 16:0 LPC/DPPC liposomes. It was shown that DPPC liposomes formed in the absence of 16:0 LPC always had a fluidity gradient in both gel and liquid-crystalline phase, while in the presence of 14.1 mol% and 27.0 mol% 16:0 LPC in the mixtures, the fluidity gradient tended to disappear below 40 degrees C. In the case of 27.0 mol% 16:0 LPC in the 16:0 LPC/DPPC mixtures the polarization of the sixteenth carbon of acyl chains was similar to that of the sixth at 10 degrees C. Small-angle X-ray diffraction showed that when increasing 16:0 LPC concentration there was a significant decrease in the 16:0 LPC/DPPC liposome thickness. Thickness of the lipid layer of DPPC was 7.30 nm, but those of the samples containing 14.1 mol% and 27.0 mol% of 16:0 LPC were reduced to 6.79 and 5.52 nm at 25 degrees C, respectively. Wide-angle X-ray diffraction showed that a reflection appeared at 0.42 nm with a broad shoulder around 0.41 nm in pure DPPC at a lipid concentration of 300 mg/mL at 25 degrees C. In the 16:0 LPC/DPPC system, a single sharp reflection appeared at 0.41 nm. It can be concluded that DPPC forms an interdigitated gel phase in the presence of 16:0 LPC concentration below 30 mol%, above this concentration micellization of the bilayers occurs. The interdigitated structures were destabilized slowly with 16:0 LPC concentration increasing, and finally the 16:0 LPC/DPPC bilayers fit into the micelles with its concentration up to 60 mol%. | 18,726,286 |
Molecular characterization of suppression of hepatitis B virus transcription by hepatitis C virus core protein. | To further elucidate the molecular mechanisms underlying the suppression of hepatitis B virus (HBV) expression by the hepatitis C virus (HCV) core protein, five molecular clones of HCV cDNA sequence containing the 5' noncoding (5'NC) and the core regions have been isolated from Chinese HBV- and HCV-coinfected patients. Sequence comparison and phylogenetic analysis showed that the HCV sequence cloned from coinfected individuals is indistinguishable from that identified in other patients. Cotransfection assay confirmed that the core protein expressed from one of the cloned sequence is capable of suppressing the expression of hepatitis B surface and e antigens (HBsAg and HBeAg, respectively). Deletion mapping revealed that the C-terminal hydrophobic region of the HCV. core is necessary for the suppression. Results from reporter assays demonstrated that HCV core protein interacts with the HBV C promoter and enhancer II elements and down-regulates the transcription of HBV as well as other cellular and heterologous viral genes in both hepatic and non-hepatic cell lines. Taken together, the findings suggest HCV core protein as a multifunctional negative regulator of transcription critically involved in the molecular interactions between HBV and HCV, and between HCV and the cell. | 18,726,290 |
Exon structure requirements for yeast tRNA ligase. | Different nucleotides were introduced into nucleotides 32, 37 and 38 of yeast tRNA(Phe) precursors via oligonucleotide directed mutations. Pre-tRNAs were prepared using T7-transcription in vitro and spliced with the purified yeast tRNA endonuclease and tRNA ligase. It is demonstrated that tRNA ligase activities will be inhibited by the 5'-double-stranded end of 3'-halves. | 18,726,292 |
Sequence analysis of lacZ(-) mutations induced by ion beam irradiation in double-stranded M13mp18DNA. | While M13mp18 double-stranded DNA was irradiated with ion beam, and transfected intoE. coli JM103, a decrease of transfecting activity was discovered. The lacZ(-) mutation frequency at 20% survival could reach (3.6-16.8) x 10(4), about 2, 3-10 times that of unirradiated M13DNA. Altogether, 27 IacZ(-)mutants were selected, 10 of which were used for sequencing. 7 of the sequenced mutants show base changes in 250-bp region examined (the remaining 3 mutants probably have base changes outside the regions sequenced). 5 of the base-changed mutants contain more than one mutational base sites (some of them even have 5-6 mutational base sites in 250-bp region examined); this dense distribution of base changes in polysites has seldom been seen in X-rays, Y-rays or UV induced DNA mutations. Our experiments also showed that the types of base changes include transitions(50%), transversions (45%) and deletion (5%); no addition or duplication was observed. The transitions were mainly C-->T and A-->G; the transversions were mainly C-->A and C-->G. The mutations involving cytosine residue (in the template strand) constitute about 60% of all the base changes observed. In comparison with the surrounding sequences of mutational base sites, the base located between TG and CT is found to be easily substituted. | 18,726,305 |
Influences of cerebellar interpositus nucleus and fastigial nucleus on neuronal activity of lateral hypothalamic area. | Stimulation of cerebellar interpositus nucleus and fastigial nucleus could influence the neuronal activity of lateral hypothalamic area in the cat, and some of the neurons which respond to the cerebellar stimulations are glucose-sensitive neurons. These results suggest that the cerebellum is involved not only in motor control, but also in the regulation of non-somatic functions through the cerebello-hypothalamic pathways. | 18,726,314 |
Combined therapy of p53-wt and drug in an orthotopic multidrug-resistant human lung cancer model. | Balb/c nu/nu mice were inoculated intratracheally with multidrug-resistant human lung cancer cells GLK containing p53 mutation at codon 245 and treated with intratracheal instillation of p53-wt retroviral vector (pDOR53W) to increase cell chemosensitivity, and then with intraperitoneal injection of doxorubicin. 30 d after tumor cell inoculation, 75% of the control mice showed macroscopic tumors in the lung. Sole pDOR53W suppressed GLK tumor formation in 68% of mice; sole doxorubicin 33.3%, but the combination of pDOR53W and doxorubicin 88.9 %. The exogenous p53 sequence was detected and confirmed in the tumor that grew after treatment with pDOR53W retroviral vector by PCR and Southern blot hybridization with p53 cDNA. These results suggested that direct administration of a retroviral vector expressing p53-wt combined with treatment of anticancer agent was an effective therapeutic method for multidrug-resistant human lung cancer. | 18,726,321 |
Regeneration of foreign genes co-transformed plants of Medicago sativa L by Agrobacterium rhizogenes. | Gene encoding sulphur amino acid-rich protein (HNP) and rol genes were transferred into Medicago sativa L (alfalfa) mediated by Agrobacterium tumafeciens. Regeneration of transgenic plants was induced successfully from hairy root tissue of cotyledon in alfalfa. Cotyledon tissues were an ideally transformed recipient. There was a negative correlation between age of hairy roots and embryogenesis frequency in alfalfa. Production of co-transformed plants with greater yield and super quality was important for development of new alfalfa varieties. | 18,726,342 |
Comparative study on direction selectivity and functional organization of the primary visual cortical cells in monkeys and cats. | Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area Vl in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways. | 18,726,351 |
Mediation by calcium/calmodulin-dependent protein kinase II of suppression of GABA(A) receptors by NMDA. | Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on gamma-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA-and muscimol (Mus)-activated currents (I(gaba) and I(Mus)), respectively in the Mg(2+)-free external solution containing 1 mumol/L glycine at a holding potential (V ( H )) of -40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 gammamol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of I(gaba); (ii) when the neurons were incubated in a Ca(2+)-free bath or pre-loaded with a membrane-permeable Ca(2+) chelator, BAPTA AM (10 mumol/L), the inhibitory effect of NMDA on I(GAba) disappeared. Cd(2+) (10 mumol/L) or La(3+) (30 mumol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppression of I(gaba) by NMDA application; (iii) the suppression of I(GAba) by NMDA was inhibited by KN-62, a calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results indicated that the inhibition of GABA response by NMDA is Ca(2+)-dependent and CaMKII is involved in the process of the Ca(2+)-dependent inhibition. | 18,726,361 |
Differential recognition of MHC class I molecules of xeno-/allo-endothelial cells by human NK cells. | Using human umbilical vein endothelial cells (HUVEC) and porcine aortic endothelial cells (PAEC) as target cells, human peripheral blood NK cells (PBNK) and NK92 cells as effector cells, the differential cytotoxicities of NK cells to allo- and xeno-endothelial cells were studied. The influence of MHC class I molecules on the cytotoxicity of human NK cells was assayed using acid treatment, and blockades of MHC class I antigens, CD94 and KIR (NKB1). The results indicated that the killing of PAEC by the two kinds of NK cells is higher than that of HUVEC. After acid treatment, the cytotoxicity of the two kinds of NK cells to PAEC and HUVEC is significantly enhanced, but the magnitude of the enhancement is different. The enhancement of NK killing to acid treated HUVEC is much greater than that to PAEC. Blockade of CD94 mAb did not alter the NK cytotoxicity, while blockade of NKB1 mAb enhanced the cytotoxicity of PBNK to HUVEC and PAEC by 95% and 29% respectively. The results above suggested that the differential recognition of MHC I molecules of xeno-endothelial cells by human NK cells could be the major reason for higher NK cytotoxicity to PAEC. KIR might be the primary molecule that transduced inhibitory signals when endothelial cells were injured by NK cells. | 18,726,370 |
Expansion of CD34(+) cells from human umbilical cord blood by FL and/or TPO gene transfected human marrow stromal cell lines. | To elucidate the effect of gene transfected marrow stromal cell on expansion of human cord blood CD34(+) cells, a culture system was established in which FL and TPO genes were transfected into human stromal cell line HFCL. To establish gene transfected stromal cells co-culture system, cord blood CD34(+) cells were purified by using a magnetic beads sorting system. The number of all cells and the number of CD34(+) cells and CFC (CFU-GM and BFU-E) were counted in different culture systems. The results showed that in all 8 culture systems, SCF+IL-3+HFT manifested the most potent combination, with the number of total nucleated cells increasing by (893.3 +/-52.1)-fold, total progenitor cells (CFC) by (74.5 +/-5.2)-fold and CD34(+) cells by 15.7-fold. Maximal expansions of CFC and CD34(+) cells were observed at the end of the second week of culture. Within 14 days of culture, (78.1 +/- 5.5)-fold and (57.0 +/- 19.7)-fold increases in CFU-GM and BFU-E were obtained. Moreover, generation of LTC-IC from amplified CD34(+) cells within 28 days was found only in two combinations, i.e. SCF+IL-3+FL+TPO and SCF+IL-3+HFT, and there was no significant difference between these two groups statistically. These results suggest that human umbilical cord blood CD34(+) cells can be extensively expanded ex vivo by using gene transfected stromal cells along with cytokines. | 18,726,391 |
Comparative study of symmetric and asymmetric somatic hybridization between common wheat andHaynaldia villosa. | Symmetric and asymmetric protoplast fusion between long term cell suspension-derived protoplasts ofTriticum aestivum (cv. Jinan 177) and protoplasts ofHaynaldia villosa prepared from one-year-old embryogeneric calli was performed by PEG method. In asymmetric fusion, donor calli were treated with gamma ray at a dose of 40, 60, 80 Gy (1.3 Gy/min) respectively and then used to isolate protoplasts. Results of morphological, cytological, biochemical (isozyme) and 5S rDNA spacer sequence analysis revealed that we obtained somatic hybrid lines at high frequency from both symmetric and asymmetric fusion. Hybrid plants were recovered from symmetric and low dose gamma-fusion combinations. GISH (genomicin situ hybridization) analysis proved exactly the existence of both parental chromosomes and the common occurrence of several kinds of translocation between them in the hybrid clones regenerated from symmetric and asymmetric fusion. And the elimination of donor DNA in hybrid clones regenerated from asymmetric fusion combinations was found to increase with the increasing gamma doses. It is concluded that transference and recombination of nuclear DNA can be achieved effectively by symmetric and asymmetric fusion, hybrids with small fragment translocation which are valuable in plant breeding can be obtained directly by asymmetric fusion. | 18,726,409 |
GABA/progesterone-induced polyphosphoinositide (PPI) breakdown and its role in the acrosome reaction of guinea pig spermatozoa in vitro. | To investigate whether GABA/progesterone (P(4)) stimulates PPI breakdown and its role in the acrosome reaction (AR), spermatozoa of guinea pig were preincubated in MCM-LCa(2+) for 5.5 h and then labeled with [(32)P]pi for 1 h. Samples were washed through a three-step gradient Percoll, adjusted to 5x10(7) cells/mL and exposed to 2 mmol/L Ca(2+), 5 micromol/L GABA, 10 micromol/L P(4) and other agents. Lipids were separated by t.l.c. and radioactivity in spots determined by scintillation counting. The AR was assessed by phase-contrast microscopy. The results showed that (i) when spermatozoa were treated with GABA,(32)P-label diminished rapidly in phosphatidylinositol 4, 5-bisphosphate (PIP(2)), phosphatidylinositol 4-phosphate (PIP), and increased in phosphatidic acid (PA). The loss of label from PPI was almost completed by 10 min. The time-course of the AR was much slower than PPI when spermatozoa reached a maximal response by 15 min; (ii) the pattern of PPI hydrolysis and stimulation of AR was similar for the three agonists tested; their potency followed the order A23187>progesterone> or =GABA; (iii) GABA-induced PIP(2) hydrolysis and rise in PA and the AR were prevented by inclusion of 10 mmol/L neomycin; (iv) the loss of PIP(2) labeling and the increase in PA labeling abolished when spermatozoa were exposed to EGTA or Ca(2+) channel blocker. These results indicate that GABA or P(4)-induced PPI breakdown is an important and essential event in the series of changes to membrane fusion during the AR of guinea pig spermatozoa and this effect is mediated via calcium by activation of phosphatidylinositol-specific phospholipase C. | 18,726,415 |
Three-dimensional structure of the Chinese Sacbrood bee virus. | The RNA of Chinese Sacbrood Bee Virus (CSBV) was purified and used as template to obtain a 1096 bp cDNA fragment by RT-PCR amplification. This DNA fragment was cloned into pGEM-T Easy Vector for sequencing. Analyses of the sequenced CSBV RNA fragment revealed a nucleotide sequence homology of 87.6% and a deduced amino-acid sequence homology of 94.6% with that of the Sacbrood Virus (SBV), indicating that CSBV is a different but highly homologous virus of SBV. The three-dimensional (3D) structure of CSBV was determined at 2.5 nm resolution by using electron cryo-microscopy (cryoEM) and computer reconstruction methods. The 3-D structure showed that the capsid has aT = 1 (or P = 3) icosahedral capsid shell with a smooth surface. There were 12 pentons at its icosahedral vertices (5-fold axes) and 132 holes penetrating the shell. The 3-D structure also revealed densities corresponding to the CSBV genome, suggesting icosahedrally-ordered RNA organization, a novel feature not previously reported for any picornaviruses. | 18,726,426 |
Laser-induced tobacco protoplast fusion. | Laser tweezers can manipulate small particles, such as cells and organelles. When coupling them with laser microbeam selective fusion of two tobacco protoplasts containing some chloroplast was achieved. Physical and biological variables that affect laser trapping and laser-induced fusion were also discussed. The results show that the effect of chloroplast content and distribution on the yield of cell fusion is remarkable. | 18,726,463 |
Engineering human interferon alpha1c/86D with phage display technology. | Human interferon-alpha1c/86D (IFNalpha1c/86D) was functionally displayed on the surface of the filamentous bacteriophage using a phagemid vector system (pCANTAB5E). The key amino acid residues involved in the receptor binding were further defined with phage displayed 6-mer peptide library and two neutralizing antibodies against linear epitopes on the IFN-alpha1b, indicating that residues 30, 33, 34, (AB-loop) and residues 124, 126, 127 (D helix, DE-loop) were more critical than the adjacent residues for recognition of receptor. In addition, a cassette mutagenesis library was generated by fully randomizing the sequence of the four positions 29, 31, 32 and 35 in AB-loop, and used to select phage-IFN variants with WISH-based panning method. Three phage-IFN variants were isolated to possess more antiviral activity in the range of 4-16-fold than parental phage-IFN after IPTG-induced soluble expression. The results suggest that phage displayed phage-IFN alpha1c/86D variants with increased specific activity might be obtained after purification procedures. | 18,726,473 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.