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2487272 | Cytochalasin prevents cell elongation and increases potassium efflux from embryonic lens epithelial cells: implications for the mechanism of lens fiber cell elongation. | Treatment of cultured embryonic lens epithelial cells with vitreous humor causes them to differentiate into lens fibers. Fiber differentiation is characterized by extensive cell elongation. We have previously suggested that potassium accumulation provides the driving force for the early, rapid phase of this process. Cy... |
2642042 | Optical enrichment of dansyl-rac-amino acids by formation of crystalline inclusion complexes with cyclodextrins. | Optical enrichment from racemic dansyl-leucine, dansyl-norleucine, and dansyl-phenylalanine with both beta- and gamma-cyclodextrins in water is reported. Initial crystallization yielded the dansyl-L-Leucine isomer complexed in excess with beta-cyclodextrin with an optical purity of 62-78% depending on experimental cond... |
2642036 | A general criterion for molecular recognition: implications for chiral interactions. | A general criterion is formulated for molecular recognition. The criterion for recognition is the inequality of the distance matrices of complexes of different compounds with a resolving agent under ambient experimental conditions. It is shown how this criterion provides for an objective, well-defined, and simple expla... |
2642034 | Liquid chromatographic separation of anomeric forms of saccharides with cyclodextrin bonded phases. | A brief review of sugar stereochemistry is given. The separation of 34 different pairs of anomers was accomplished on both alpha- and beta-cyclodextrin columns. Five different mobile phases were evaluated. The separation of anomers could be enhanced or suppressed by altering the mobile-phase composition, column tempera... |
2642033 | Determination of terbutaline enantiomers in biological samples using liquid chromatography with coupled columns. | The purpose of this work was to develop and validate a method for the separation and determination of the enantiomers of terbutaline in plasma and intestinal juice. Terbutaline was extracted from plasma and intestinal juice by liquid-solid extraction on small C18 cartridges. The extract was then analyzed by coupled col... |
2561183 | Oral, topical and parenteral antifungal treatment with itraconazole in normal and in immunocompromised animals. | Itraconazole was dissolved in polyethylene glycol for oral and topical treatment and in hydroxypropyl-beta-cyclodextrin for oral, topical or parenteral treatment. Topical and oral treatment was successful in microsporosis, trichophytosis, skin-and vaginal candidosis, pityrosporosis and eye mycosis by Candida, Fusarium ... |
2697532 | The chemistry, photophysics and photosensitizing properties of phthalocyanines. | Phthalocyanines (Pcs) and naphthalocyanines (Ncs) are being extensively studied as photosensitizers for photodynamic therapy (PDT) of cancer. They strongly absorb clinically useful red light, with maxima around 670 nm and 770 nm respectively. Chelated with appropriate diamagnetic metal ions, they exhibit high triplet y... |
2516462 | Elevated accumulation of hyaluronate in the tubular bones of osteogenesis imperfecta. | The content and composition of glycosaminoglycans in the tubular bones of osteogenesis imperfecta were compared to those in the tubular bones of age-matched controls. Chondroitin sulfate was the major glycosaminoglycan (70-80% of total) both in the normal and pathological bones, and its level, based on the tissue wet w... |
2482635 | [Structure and antigenicity of the glomerular basement membrane]. | The glomerular basement membrane is a complex extracellular matrix formed of various molecules which build a supramolecular network. The major structural components are collagen IV, laminin, heparan sulfate proteoglycan, and nidogen/entactin. Cross-reacting antibodies against laminin, nidogen, and collagen IV may occur... |
2694266 | Problems associated with the preparation of whole mounts of cytoskeletons for high resolution electron microscopy. | The resolution currently available in both transmission and scanning electron microscopes is theoretically adequate to visualize the organization of the cytoskeleton at the supramolecular and macromolecular levels. However, achieving this resolution in practice requires that the methods used to prepare the specimens bo... |
2692590 | Autoantibody idiotypy and neonatal B cell repertoire. | During ontogeny, antibody variable (V) regions are subjected to selection events at the level of B-cell clones bearing on their surfaces Ig molecules useful to the developing organism. Antigenic determinants of immunoglobulin V regions (idiotypes) are believed to play an essential role in molecular recognition and immu... |
2513697 | Monomerizing effect of caffeine, o-phenanthroline, and tannin on cationic dyes: a model system to analyze spectral characteristics of the intercalative binding to nucleic acids. | If used as co-solutes in concentrated solutions of cationic planar dyes, caffeine, o-phenanthroline, and tannin induce striking hyperchromic and bathochromic shifts in their absorption spectra. Likewise, the fluorescence of acridine orange at high concentration greatly increases in the presence of caffeine, the emissio... |
2598174 | Biological characterization of a chimeric mouse-human IgM antibody directed against the 17-1A antigen. | A chimeric antibody was constructed in which the murine H- and L-chain variable regions of mAb 17-1A, raised against human colorectal cancer cells, were joined with the human constant mu and kappa regions. Transfection of these constructs into the murine myeloma Sp2/0 resulted in the expression and secretion of a penta... |
2590460 | Effects of 2-hydroxypropyl-beta-cyclodextrin on the aqueous solubility of drugs and transdermal delivery of 17 beta-estradiol. | The effect of 2-hydroxypropyl-beta-cyclodextrin (2-HPCD) on the aqueous solubility of 18 drugs possessing different physiochemical properties was investigated. The largest increase in aqueous solubility was obtained with very lipophilic drugs with low aqueous solubility and the enhancement was larger at low temperature... |
2551609 | Glycoprotein oligosaccharides as recognition structures. | A series of observations--the pronounced changes in the expression and distribution of oligosaccharide antigens during embryonic development, cell differentiation and oncogenesis, the prominence of these changing structures (oncodevelopmental antigens) on the receptor for epidermal growth factor, and the stimulation of... |
2791556 | Electron microscopic evidence for elastin-like supramolecular organization in synthetic polytripeptides. | Electron microscope studies have been carried out on polytripeptides comprising the sequences -Pro-X-Gly- and -X-Pro-Gly- (X = Val, Ile, Met). These polymers have previously been shown to either contain or lack secondary structure. The formation of aligned filaments and also, in some cases, of banded fibers has been de... |
2675054 | The role of the complement system in the pathogenesis of multiple organ failure in shock. | The results of our experiments suggest that the development of MOF is the result of a concerted autodestructive inflammatory process affecting the endothelium which is probably triggered off by the complement system. The combination of two noxious events (application of a low dose of endotoxin during hemorrhagic shock)... |
2673795 | Comparison of faecal blood loss, upper gastrointestinal mucosal integrity and symptoms after piroxicam beta-cyclodextrin, piroxicam and placebo administration. | In order to evaluate the gastric tolerance of the new piroxicam formulation CHF 1194 (piroxicam complexed with beta-cyclodextrin), a double-blind randomized trial was carried out in 21 young healthy volunteers comparing CHF 1194 with piroxicam and placebo. Faecal blood loss measurement by the Cr-51 labelled red blood c... |
2773647 | Biological tests for opiate activity of newly-synthesized compounds--opioid peptides and cyclic beta-diketones. | A group of newly-synthesized (Leu5) enkephalinamides and their derivatives, with incorporated D-amino acids, as well as a group of cyclic beta-diketones from the group of 1, 3-indandiones, were partially pharmacologically characterized in experiments in vivo and in vitro. The substances studied, applied subcutaneously ... |
2548811 | Microbial amylolytic enzymes. | Starch-degrading, amylolytic enzymes are widely distributed among microbes. Several activities are required to hydrolyze starch to its glucose units. These enzymes include alpha-amylase, beta-amylase, glucoamylase, alpha-glucosidase, pullulan-degrading enzymes, exoacting enzymes yielding alpha-type endproducts, and cyc... |
2762275 | The pancreatic ductal system of the rat: cell diversity, ultrastructure, and innervation. | The morphological features and innervation of the pancreatic ductal epithelium of the rat was investigated. For the purposes of this study, pancreatic ducts were classified as either intercalated, intralobular, interlobular, or main. Epithelial cells of these different classes were classified as either principal or spe... |
2754295 | Preparation and evaluation in rabbits of topical solutions containing forskolin. | Forskolin, a diterpene which displays a potent IOP-lowering activity in several animal species, is very poorly water soluble. This characteristic imposes the ocular administration of the drug as a suspension, a type of formulation which may present several preparative and biological disadvantages, such as e.g. difficul... |
2472794 | [Regulation of the supramolecular structure and the catalytic activity of gamma-glutamyltransferase in the reversed micelle system]. | Regulation mechanisms of the supramolecular structure and the catalytic activity of a heterodimeric enzyme, gamma-glutamyltransferase, in the system of Aerosol OT (AOT) reversed micelles in octane have been studied. gamma-(3-carboxy-4-nitro)-glutamic acid anilide (L- and D-isomers) and glycylglycine were used as substr... |
2500826 | Trends and prospects of bio-medical electron microscopy. | Prognostic ideas of the development of the bio-medical electron microscopy in the forthcoming decades to the 21st century include following points: 1. Development and improvement of electron microscopes with which one and the same point of a tissue section can be analysed in a wide spectrum of magnifications ranging fr... |
2738122 | Evaluation of the liquid chromatographic separation of monosaccharides, disaccharides, trisaccharides, tetrasaccharides, deoxysaccharides and sugar alcohols with stable cyclodextrin bonded phase columns. | Both alpha- and beta-cyclodextrin (CD) bonded phase columns were evaluated for their ability to separate carbohydrates and related molecules. Chromatographic data on approximately 50 solutes are reported. Mobile phases consisting of acetonitrile-water or acetone-water produce the best separations. Separations could be ... |
2732538 | [Surgical treatment of postinfarction ventricular septal perforation--the difference between a cardiogenic shock group and a congestive heart failure group]. | Twelve patients with postinfarction ventricular septal perforation (VSP) were divided into 2 groups based upon the preoperative status and the time interval between the operation and the occurrence of VSP after acute myocardial infarction (AMI). Group I were in cardiogenic shock unresponsive to either pharmacologic sup... |
2471701 | A comparative study of PAS-phosphotungstic acid-Diamine Supra Blue FGL and immunological reactions for type I collagen. | Immunohistochemical techniques proved valuable in histological studies of various types of collagens. However drawbacks include non-specific reactions of antibodies, masking of antigens, and the high cost of antibodies. This study was undertaken to ascertain the specificity of the PAS-phosphotungstic acid-Diamine Supra... |
2543336 | An attempt to reduce the photosensitizing potential of chlorpromazine with the simultaneous use of beta- and dimethyl-beta-cyclodextrins in guinea pigs. | The effects of topically applied beta-cyclodextrin (beta-CyD) and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CyD) on photoallergic contact dermatitis due to chlorpromazine hydrochloride (CPZ) were investigated using the photomaximization technique in guinea pigs. From the gross and histological observations, ... |
2726987 | Determination of thermodynamic parameters of complexation using a nonlinear regression method. | The new model and method introduced here allow the determination of more than one unknown from one set of raw experimental data. Even though the method was used to treat data from the complexation of phenytoin with cyclodextrins, the same approach could be exploited for other drug interaction systems. The method allows... |
2542149 | From the neuroendocrinology of lymphocytes toward a molecular basis of the network theory. | The cells of the immune system produce and respond to hormones that were once thought to be restricted to the neuroendocrine system. By applying a novel methodology based on the molecular recognition hypothesis, the isolation and purification of receptors shared between the immune and neuroendocrine systems was accompl... |
2720852 | Effect of the interaction of drug-beta-cyclodextrin complex with bile salts on the drug absorption from rat small intestinal lumen. | This investigation was concerned with the change of the bioavailability of a drug owing to the interaction of the drug-beta-cyclodextrin complex with bile salts in rat intestinal lumen. The absorption of sulfamethizole (SMZ) from rat intestinal lumen after administration of SMZ-beta-cyclodextrin complex was determined ... |
2720141 | Supramolecular organization of tricarboxylic acid cycle enzymes. | We propose a spatial structure for the tricarboxylic acid cycle enzyme complex (tricarboxylic acid cycle metabolon). The structure is based on an analysis of data on the interaction between tricarboxylic acid cycle enzymes and the mitochondrial inner membrane, as well as on data on enzyme-enzyme interactions. The alpha... |
2497788 | Membrane structure and dynamics by 2H- and 31P-NMR. Effects of amphipatic peptidic toxins on phospholipid and biological membranes. | The actions of bee venom melittin and delta-lysin from Staphylococcus aureus on membranes have been monitored by solid-state deuterium and phosphorus NMR and shown to differ depending on temperature and on the lipid-to-peptide molar ratio Ri. In the gel phase of phosphatidylcholine model membranes, for lipid-to-peptide... |
2470416 | Structure and supramolecular architecture of membrane channel-forming peptides. | Peptides gathering together to induce channels in lipid bilayers may be classified in several categories according to the spatial structures involved. For example, gramicidin A forms intramolecular tubes, alamethicin, bundles of helical rods with intermolecular pores, porins (being proteins, properly speaking) are rich... |
2717647 | Effects of roll mixing with beta-cyclodextrin on enhancing solubilities of water insoluble drugs. | To increase a solubility of water insoluble drugs by the use of roll mixing with beta-cyclodextrin (CyD), equilibrium concentrations of ten medicinal drugs indomethacin, griseofulvin, nifedipine and so on were examined in comparison with those of different mixed systems as kneading with water and physical mixing. The e... |
2715279 | Determination of hydroxypropyl-beta-cyclodextrin in plasma and urine by size-exclusion chromatography with post-column complexation. | The analytical method described here provides the appropriate sensitivity and selectivity for the determination of unlabelled hydroxypropyl-beta-cyclodextrin as a parenteral carrier in pharmaceutical formulations. The method may also be used in clinical trials evaluating the fate and pharmacokinetic profile of this com... |
2523676 | Studies on bis(crown ether)-based ion-selective electrodes for the potentiometric determination of sodium and potassium in serum. | Bis(crown ether)-based ion-selective electrodes for sodium and potassium are described, based on the bis[(12-crown-4)-2-ylmethyl]-2-dodecyl-2-methyl malonate sensor(I) for sodium and the bis[(benzo-15-crown-5)-15-ylmethyl] pimelate sensor(II) for potassium. The best results were obtained when the sensors were used in a... |
2468675 | Brain tissue reaction to permselective polymer capsules. | The brain tissue reaction to permselective polymer capsules implanted in rats was evaluated for 1 to 54 weeks. The polymer capsules were well tolerated in all animals and no recognizable neurological or behavioral deficits were associated with the implants. Necrosis at the brain/polymer interface, as assessed with Niss... |
2651008 | Cell sorting out: the self-assembly of tissues in vitro. | The question posed by the science of analytical histology is how the properties and interactions of the components of the tissues determine their organization in the organs. The relevant components of the tissues are the cells and the extracellular matrix. The ability of cohering populations of cells to self-assemble s... |
2930471 | Comparison of the flux of carbon to hepatic glycogen deposition and fatty acid and cholesterol synthesis on refeeding rats fed ad libitum or meal-fed rats with a chow-diet meal. | Meal-fed rats and rats fed ad libitum had similar rates of hepatic glycogen deposition on refeeding with a chow meal. In contrast, the rate of hepatic lipid synthesis (cholesterol plus fatty acids) was 6-fold higher on refeeding in the meal-fed group compared with the 'ad libitum' group. There were no significant diffe... |
2538942 | Antagonism of ethanol effects by Ro 15-4513: an electrophysiological analysis. | Ethanol (ETH) and general anesthetics have been reported to facilitate the chloride channel opening, possibly, or at least partly, through an interaction with the GABA-benzodiazepine (BZ) receptor-gated chloride ionophore "supramolecular complex". Recently Ro 15-4513, a novel BZ ligand, has been indicated as a potent a... |
2564674 | Fimbriae of Bacteroides nodosus: protein engineering of the structural subunit for the production of an exogenous peptide. | The pattern of sequence variation between Bacteroides nodosus fimbrial subunits of different serotypes suggests a degree of flexibility, which might be exploited for protein engineering approaches for the expression of other peptides. We have tested this using the well-characterized peptide epitope from VP1 of foot-and... |
2927390 | Replication of DNA minicircles in kinetoplasts isolated from Crithidia fasciculata: structure of nascent minicircles. | We have previously described an isolated kinetoplast system from Crithidia fasciculata capable of ATP-dependent replication of kinetoplast DNA minicircles (L. Birkenmeyer and D.S. Ray, J. Biol. Chem. 261: 2362-2368, 1986). We present here the identification of two new minicircle species observed in short pulse-labeling... |
2538717 | DNA topoisomerase II must act at mitosis to prevent nondisjunction and chromosome breakage. | The hypothesis that DNA topoisomerase II facilitates the separation of replicated sister chromatids was tested by examining the consequences of chromosome segregation in the absence of topoisomerase II activity. We observed a substantial elevation in the rate of nondisjunction in top2/top2 cells incubated at the restri... |
2493724 | Biochemistry of basement membranes. | Basement membranes are thin (20 to 300 nm) extracellular matrices with a ubiquitous occurrence in the body. They consist mainly of collagenous and noncollagenous glycoproteins, are formed early during embryonic development, and in mature tissues they compartmentalize various types of cells and tissue structures. The cl... |
2921943 | Evolution of homologous domains of cytoplasmic intermediate filament proteins and lamins. | The earliest gene duplications in the evolution of the intermediate filament proteins created the ancestors of acidic keratins, basic keratins, nonepithelial intermediate filament proteins, and lamins. Biochemistry and function of cytoplasmic intermediate filaments differ greatly from those of lamins. Cytoplasmic inter... |
2920026 | Partial purification and characterization of a formylmethionine deformylase from rat small intestine. | A formylmethionine deformylase from rat small-intestinal mucosa has been isolated, characterized and partially purified. The enzyme catalyses the release of equimolar amounts of formate and the free amino acid. The deformylase was active against formylmethionine (Km 7.1 mM) and formylnorleucine, but showed reduced acti... |
2920010 | Transient-time analysis of substrate-channelling in interacting enzyme systems. | The kinetics of dynamically interacting enzyme systems is examined, in the light of increasing evidence attesting to the widespread occurrence of this mode of organization in vivo. The transient time, a key phenomenological parameter for the coupled reaction, is expressed as a function of the lifetime of the intermedia... |
2536665 | Cloning and analysis of genes involved in coenzyme B12 biosynthesis in Pseudomonas denitrificans. | Cobalamin synthesis probably requires 20 to 30 different enzymatic steps. Pseudomonas putida and Agrobacterium tumefaciens mutants deficient in cobalamin synthesis (Cob have been isolated. In P. putida, Cob mutants were identified as being unable to use ethanolamine as a source of nitrogen in the absence of added cobal... |
2914854 | Peptidoglycan-polysaccharide complex in the cell wall of the filamentous prochlorophyte Prochlorothrix hollandica. | A peptidoglycan-polysaccharide complex composed of N-acetylglucosamine, N-acetylmuramic acid, muramic acid 6-phosphate, L-alanine, D-alanine, D-glutamic acid, meso-diaminopimelic acid, N-acetylmannosamine, mannose, galactose, glucose, and phosphate was isolated from cell walls of the filamentous prochlorophyte Prochlor... |
2464578 | A single gene directs synthesis of a precursor protein with beta- and alpha-amylase activities in Bacillus polymyxa. | The Bacillus polymyxa amylase gene comprises 3,588 nucleotides. The mature amylase comprises 1,161 amino acids with a molecular weight of 127,314. The gene appeared to be divided into two portions by the direct-repeat sequence located at almost the middle of the gene. The 5' region upstream of the direct-repeat sequenc... |
2914851 | Pattern of action of Bacillus stearothermophilus neopullulanase on pullulan. | The action of neopullulanase from Bacillus stearothermophilus on many oligosaccharides was tested. The enzyme hydrolyzed not only alpha-(1----4)-glucosidic linkages but also specific alpha-(1----6)-glucosidic linkages of several branched oligosaccharides. When pullulan was used as a substrate, panose, maltose, and gluc... |
2464046 | Ultrastructural analysis of substance P-immunoreactive nerve fibers in myenteric ganglia of guinea pig small intestine. | Electron microscopic immunocytochemistry has been used to study the distribution and synaptic relationships of substance P (SP)-immunoreactive nerve fibers in ultrathin sections from whole-mount preparations of myenteric ganglia from guinea pig small intestine. At the light microscopic level, myenteric ganglia stained ... |
2911722 | Structural origins of high-affinity biotin binding to streptavidin. | The high affinity of the noncovalent interaction between biotin and streptavidin forms the basis for many diagnostic assays that require the formation of an irreversible and specific linkage between biological macromolecules. Comparison of the refined crystal structures of apo and a streptavidin:biotin complex shows th... |
2492108 | Recombinant system for overexpression of cholera toxin B subunit in Vibrio cholerae as a basis for vaccine development. | We have constructed an overexpression system in which the gene encoding the B subunit of cholera toxin (CTB) was placed under the control of the strong tacP promoter in a wide host range plasmid. Recombinant nontoxigenic classical and E1 Tor Vibrio cholerae strains of different serotypes harboring this plasmid excreted... |
2643083 | Effects of substrate structure on the kinetics of circle opening reactions of the self-splicing intervening sequence from Tetrahymena thermophila: evidence for substrate and Mg2+ binding interactions. | The self-splicing intervening sequence from the precursor rRNA of Tetrahymena thermophila cyclizes to form a covalently closed circle. This circle can be reopened by reaction with oligonucleotides or water. The kinetics of circle opening as a function of substrate and Mg2+ concentrations have been measured for dCrU, rC... |
2536046 | Lipopolysaccharide priming of human neutrophils for an enhanced respiratory burst. Role of intracellular free calcium. | Lipopolysaccharide (LPS) pretreatment "primes" neutrophils to release increased amounts of superoxide anion (O2-) when stimulated. We investigated the molecular basis of this enhanced activity. Comparison of kinetic parameters of the respiratory burst NADPH oxidase in unstimulated LPS-primed and control neutrophils dis... |
2463268 | Use of anti-HLA antibodies to mask major histocompatibility complex gene products on tumor cells can enhance susceptibility of these cells to lysis by natural killer cells. | The role of major histocompatibility gene products (i.e., HLA molecules) in rendering tumor cells resistant to natural killer (NK) cell-mediated lysis was investigated by using mouse monoclonal antibodies to bind and mask HLA or non-HLA gene products on the cell membrane of human allogeneic tumor targets. Enhanced lysi... |
2463256 | Cartilage contains mixed fibrils of collagen types II, IX, and XI. | The distribution of collagen XI in fibril fragments from 17-d chick embryo sternal cartilage was determined by immunoelectron microscopy using specific polyclonal antibodies. The protein was distributed throughout the fibril fragments but was antigenically masked due to the tight packing of collagen molecules and could... |
2535737 | Inhibition of rhinovirus attachment by neutralizing monoclonal antibodies and their Fab fragments. | Previous molecular and immunological studies have mapped four neutralization sites on human rhinovirus type 14 (B. Sherry, A. G. Mosser, R. J. Colonno, and R. R. Rueckert, J. Virol. 57:246-257, 1986). Eight monoclonal antibodies, one pair for each of the four target sites and all belonging to a single isotype, immunogl... |
18964711 | Synthesis and analytical capabilities of fluorogenic ring-substituted crown ethers. | Fluorogenic crown ethers do not generally produce enough signal to be analytically useful. The incorporation of fluorogens in the crown ether ring can considerably increase the fluorescence intensity obtained on complexation, to 2-6 times that of the blank. The disadvantage is a loss of selectivity all the alkali metal... |
18964690 | The utility of time-resolved emission spectroscopy in the study of cyclodextrin-pyrene inclusion complexes. | The application of time-resolved emission spectroscopy to the characterization of cyclodextrin inclusion complexes of pyrene in the presence of various alcohols is described. Such measurements offer a means of selectively studying the characteristics of inclusion complexes in the presence of uncomplexed pyrene. The flu... |
1983037 | Active site complementation in engineered heterodimers of Escherichia coli glutathione reductase created in vivo. | By directed mutagenesis of the cloned Escherichia coli gor gene encoding the dimeric flavoprotein glutathione reductase, Cys-47 (a cysteine residue forming an essential charge-transfer complex with enzyme-bound FAD) was converted to serine (C47S) and His-439 (required to facilitate protonation of the reduced glutathion... |
2098597 | [Preoperative aspects of blood rheology in patients who developed multiple organ failure following cardiac surgery]. | The relationship between preoperative hemorheology and postoperative course was studied in 38 patients who had undergone open heart surgery for valvular diseases (mean age, 53 +/- 2 S.E. years). Twelve patients had multiple organ failures (MOF) one week after surgery, while the remaining 26 patients were in satisfactor... |
2096835 | Inhibitory effect of beta-cyclodextrin on ampicillin polymerization in aqueous solution. | Ampicillin polymerizes in aqueous solution to produce antigenic polymers; the polymers were separated by anion-exchange chromatography and shown to consist of a dimer, trimer, tetramer and pentamer of ampicillin by the masses found in fast atom bombardment mass spectroscopy. The presence of an intact beta-lactam ring i... |
2095562 | The pharmacokinetics of beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin in the rat. | Hydroxypropyl-beta-cyclodextrin was analyzed by HPLC using postcolumn complexation with phenolphthalein and negative colorimetric detection, with a detection limit of 20 micrograms/ml. The pharmacokinetics of beta-cyclodextrin and of hydroxypropyl-beta-cyclodextrin were studied after intravenous administration to perma... |
2092947 | Cytotoxic activity of polyacetylene compounds in Panax ginseng C. A. Meyer. | The effects of the three polyacetylene compounds, panaxynol, panaxydol and panaxytriol, on in vitro-cell growth were studied. These compounds are much different in their water-solubility. In order to increase water-solubility, solid complexes of polyacetylene compounds with alpha-cyclodextrin (CD) were prepared. Accura... |
2150965 | Hemolysis of human erythrocytes under hydrostatic pressure is suppressed by cross-linking of membrane proteins. | The effects of cross-linking of membrane proteins on hemolysis of human erythrocytes under high pressure (2.0 kbar) were examined. The membrane proteins were cross-linked by oxidation of their SH-groups with diamide (0.05-0.5 mM) under different pressures (1-1,000 bar) at which no hemolysis occurs. As the pressure duri... |
1708086 | Social and developmental biology of the myxobacteria. | Myxobacteria are soil bacteria whose unusually social behavior distinguishes them from other groups of procaryotes. Perhaps the most remarkable aspect of their social behavior occurs during development, when tens of thousands of cells aggregate and form a colorful fruiting body. Inside the fruiting body the vegetative ... |
2087221 | Role of water in some biological processes. | The state of intracellular water has been a matter of controversy for a long time for two reasons. First, experiments have often given conflicting results. Second, hitherto, there have been no plausible grounds for assuming that intracellular water should be significantly different from bulk water. A collective behavio... |
2128368 | To shape a cell: an inquiry into the causes of morphogenesis of microorganisms. | We recognize organisms first and foremost by their forms, but how they grow and shape themselves still largely passes understanding. The objective of this article is to survey what has been learned of morphogenesis of walled eucaryotic microorganisms as a set of problems in cellular heredity, biochemistry, physiology, ... |
2087220 | The single-stranded DNA-binding protein of Escherichia coli. | The single-stranded DNA-binding protein (SSB) of Escherichia coli is involved in all aspects of DNA metabolism: replication, repair, and recombination. In solution, the protein exists as a homotetramer of 18,843-kilodalton subunits. As it binds tightly and cooperatively to single-stranded DNA, it has become a prototypi... |
2085864 | [The assessment of factor VIII-related antigen in endothelial cells of pulmonary blood vessels in multiple organ failure]. | Twenty-five rabbits were randomized into test group (n = 20) and control group (n = 5). Test group animals were fed E coli [(0.4-0.6) x 10(11)/kg] by gastro-lavage and followed by hemorrhagic shock (MBP 40 mmHg for an hour) plus rapid reinfusion with the shed blood. The control group served as operation control. Twelve... |
2079656 | Binding studies of ions with cyclodextrins using ion-selective electrodes. | The use of ion-selective electrodes (ISEs) to study the binding of various organic ions to alpha- and beta-cyclodextrins (CDs) is described. The ISEs respond selectively, directly, and continuously to the activity of the free ion of interest in solution. Binding parameters (intrinsic binding constants and number of bin... |
2077690 | Tetrapyrrole assembly and modification into the ligands of biologically functional cofactors. | Data obtained using a combination of molecular biology and NMR spectroscopy has transformed our thinking about the evolution of the biochemical machinery required for the synthesis of the vital metallopigments: haem, chlorophyll, vitamin B12 and factor F430. One of the most recent advances is the discovery of a unique ... |
2074540 | [Solubilizing effect and inclusion reaction of cyclic bisdesmosides from tubers of Bolbostemma paniculatum]. | Tubeimosides I, II and III (cyclic bisdesmosides) have been isolated from Chinese cucurbitaceous crude drug Tu-bei-mu, a tuber of Bolbostemma paniculatum (Maxim.) Franquet. Solubilizing effects of these cyclic bisdesmosides on water insoluble or less-soluble compounds were examined. It was revealed that cyclic bisdesmo... |
2074220 | Lectin labelling of amoeboid microglial cells in the brain of postnatal rats. | The labelling of amoeboid microglial cells in the postnatal (2-10 days old) rat brain was studied by intracerebral injection of various lectins, including peroxidase-labelled Ricinus communis agglutinin (RCA), peroxidase-labelled isolectin Griffonia simplicifolia (GSA1-B4) and gold-labelled concanavalin A (Con A). Thre... |
2288827 | A comparison of the effects of zolpidem and placebo on respiration and oxygen saturation during sleep in the healthy elderly. | 1. In a double-blind placebo controlled trial, zolpidem 10 mg, a new imidazopyridine hypnotic drug, was administered to 10 elderly female patients and placebo to 11, all recovering from hip and knee replacement surgery. Respiratory monitoring with an inductance plethysmograph and pulse oximeter showed that treatment ov... |
2282170 | [Preliminary studies on the inclusion compound of cholate with beta-cyclodextrin]. | beta-Cyclodextrin inclusion compound has been proved able to eliminate the bitter taste of cholate and bile. A right amount of beta-cyclodextrin put in aqueous solution of cholate and bile will remove the bitter taste completely, beta-Cyclodextrin doesn't affect the identification or content determination of cholic aci... |
2282146 | Primary amine drug selective electrodes with special crown ethers as neutral carriers. | Ionophores selectively sensitive to primary amines have been synthesized which display low potentiometric selectivity coefficients for K+, Na+ and NH4+ ions, secondary and tertiary amines as well as quaternary ammonium ions. These ionophores include macrocyclic polyethers with dinaphthyl subunits and azocrown ether wit... |
2277070 | Microinjection of nonmuscle and smooth muscle caldesmon into fibroblasts and muscle cells. | Caldesmon is present in a high molecular mass form in smooth muscle and predominantly in a low molecular mass form in nonmuscle cells. Their biochemical properties are very similar. To examine whether these two forms of caldesmon behave differently in cultured cells, we microinjected fluorescently labeled smooth muscle... |
2271691 | Interaction of a macrocyclic bisacridine with DNA. | The binding of the macrocycle SDM to DNA was investigated by visible spectroscopy, stopped-flow kinetics, and NMR spectroscopy. SDM is composed of two 9-aminoacridines linked via the amino groups by a spermine side chain and via the 4-positions by a N,N'-[(methylthio)ethyl]succinamide side chain [Zimmerman, S. C., Lamb... |
1702787 | Deletions in epidermal keratins leading to alterations in filament organization in vivo and in intermediate filament assembly in vitro. | To investigate the sequences important for assembly of keratins into 10-nm filaments, we used a combined approach of (a) transfection of mutant keratin cDNAs into epithelial cells in vivo, and (b) in vitro assembly of mutant and wild-type keratins. Keratin K14 mutants missing the nonhelical carboxy- and amino-terminal ... |
2125301 | Transport of influenza HA from the trans-Golgi network to the apical surface of MDCK cells permeabilized in their basolateral plasma membranes: energy dependence and involvement of GTP-binding proteins. | A procedure employing streptolysin O to effect the selective permeabilization of either the apical or basolateral plasma membrane domains of MDCK cell monolayers grown on a filter support was developed which permeabilizes the entire monolayer, leaves the opposite cell surface domain intact, and does not abolish the int... |
2269656 | Targeting of a cytosolic protein to the nuclear periphery. | The yeast nuclear envelope protein NSP1 is located at the nuclear pores and mediates its essential function via the carboxy-terminal domain. The passenger protein, cytosolic dihydrofolate reductase from mouse, was fused to the 220 residue long NSP1 carboxy-terminal domain. When expressed in yeast, this chimeric protein... |
1702626 | Molecular composition of type VI collagen. Evidence for chain heterogeneity in mammalian tissues and cultured cells. | The chain composition and relative abundance of type VI collagen synthesized by cells cultured from foetal bovine nuchal ligament and skin were compared with those of the type VI collagen present in these foetal tissues. Immunoprecipitation of intact collagen VI from medium and cell layers of nuchal ligament fibroblast... |
2176466 | Possible role and mechanism of action of dissolved calcium in the degradation of bone collagen by lysosomal cathepsins and collagenase. | Equilibrium experiments with bone powder, at pH values ranging from 6.3 to 3.5, show a linear relation between log([Ca2+]/[Ca2+]0) (where [Ca2+]0 = 1 M-Ca2+) and pH, indicating that [Ca2+] could reach levels of 25 mM at pH 5 and 90 mM at pH 4. These elevated Ca2+ concentrations stimulated the lysis of insoluble bone co... |
2176465 | Inositol 1,3,4,5-tetrakisphosphate-induced release of intracellular Ca2+ in SH-SY5Y neuroblastoma cells. | Inositol-polyphosphate-induced Ca2+ mobilization was investigated in saponin-permeabilized SH-SY5Y human neuroblastoma cells. Ins(1,4,5)P3 induced a dose-related release from intracellular Ca2+ stores with an EC50 (concn. giving half-maximal effect) of 0.1 microM and a maximal release of 70%. Ins(1,3,4)P3, DL-Ins(1,4,5... |
2268264 | Molecular-mass heterogeneity of Griffonia simplicifolia lectin IV subunits. Differences in the oligosaccharide moieties in the N-terminal region. | Lectin IV of Griffonia simplicifolia (Mr approximately 56,000), which has a strong affinity for both the Lewis b and Y blood-group determinants, is a dimeric protein of two subunits, alpha (29 kDa) and beta (27 kDa), separable by SDS/PAGE and containing covalently linked oligosaccharide. After digestion with N-glycanas... |
2266565 | RecA protein self-assembly. II. Analytical equilibrium ultracentrifugation studies of the entropy-driven self-association of RecA. | We have investigated the self-association of RecA protein from Escherichia coli by equilibrium ultracentrifugation. Monomeric RecA (Mr = 37,842) was observed in reversible equilibrium with trimers, hexamers and dodecamers in the presence of 1.5 M-KCl, 5 mM-Hepes, 1 mM-EDTA, 2 mM-ATP (pH 7.0) at 1 degrees C. The equilib... |
2125081 | Effects of mutations at amino acid 61 in the arm of TF1 on its DNA-binding properties. | Transcription factor 1 (TF1) is the Bacillus subtilis phage SPO1-encoded member of the family of bacterial DNA-binding proteins that includes Escherichia coli HU and integration host factor (IHF). We have initiated a mutational analysis of the TF1 molecule to understand better its unique DNA-binding properties and to i... |
2265618 | Direct visualization of supercoiled DNA molecules in solution. | The shape of supercoiled DNA molecules in solution is directly visualized by cryo-electron microscopy of vitrified samples. We observe that: (i) supercoiled DNA molecules in solution adopt an interwound rather than a toroidal form, (ii) the diameter of the interwound superhelix changes from about 12 nm to 4 nm upon add... |
2148290 | Lymphoid specific gene expression of the adenovirus early region 3 promoter is mediated by NF-kappa B binding motifs. | A primary site of infection by human adenoviruses is lymphoid cells. However, analysis of the viral control elements and the cellular factors that regulate adenoviral gene expression in lymphocytes has not been reported. The adenovirus early region 3 (ES) gene products are involved in the maintenance of viral persisten... |
2175911 | Steroidogenic activity of a peptide specified by the reversed sequence of corticotropin mRNA. | The molecular recognition theory predicts that a reversed (3'----5') reading of an mRNA should yield a peptide that is structurally and functionally similar to that specified in the 5'----3' direction. We tested this idea by synthesizing a corticotropin (ACTH) analogue using a reverse reading of bovine mRNA for ACTH-(1... |
2263617 | Transcriptional regulation of interleukin 3 gene expression in T lymphocytes. | Interleukin 3 (IL-3 or multi-colony-stimulating factor) plays an important role in the hematopoietic response to inflammatory stimuli through its action on both immature and mature blood cells. Like other lymphokines, IL-3 is produced in response to activation of the T-cell receptor and protein kinase C pathways. By us... |
2263612 | High-resolution structure of a mutagenic lesion in DNA. | The self-complementary dodecanucleotide d[CGC(m6G)AATTTGCG]2 (where m6G is O6-methylguanine), which contains two m6G.T base pairs, has been analyzed by x-ray diffraction methods and the structure has been refined to a residual error of R = 0.185 at 2.0-A resolution. The m6G.T mispair closely resembles a Watson-Crick ba... |
2147948 | E3/19K from adenovirus 2 is an immunosubversive protein that binds to a structural motif regulating the intracellular transport of major histocompatibility complex class I proteins. | We have previously expressed in transgenic mice a chimeric H-2Kd/Kk protein called C31, which contains the extracellular alpha 1 domain of Kd, whereas the rest of the molecule is of Kk origin. This molecule functions as a restriction element for alloreactive and influenza A-specific cytotoxic T lymphocytes (CTL) but is... |
2123826 | An HlyB-type function is required for expression of the Enterococcus faecalis hemolysin/bacteriocin. | The nucleotide sequence of a 3,422-bp internal restriction fragment from the Enterococcus faecalis pAD1 hemolysin/bacteriocin-encoding region was determined. This fragment was associated with expression of hemolysin/bacteriocin component L and contained a 2,142-bp open reading frame. The inferred amino acid sequence re... |
2123822 | Lymphocyte receptors for pertussis toxin. | We have investigated human T-lymphocyte receptors for pertussis toxin by affinity isolation and photoaffinity labeling procedures. T lymphocytes were obtained from peripheral human blood, surface iodinated, and solubilized in Triton X-100. The iodinated mixture was then passed through pertussis toxin-agarose, and the f... |
1701189 | Monoclonal antibodies to two different epitopes in a 30-kD CNBr peptide of the K1 and K2 keratins. | Two anti-keratin monoclonal antibodies, Kab-2 and Kab-3, with specificities for different epitopes of type II (basic) human epidermal keratins, were produced. These antibodies had different immunofluorescent staining patterns on human fetal epidermis. Western blots and solid phase RIA showed both antibodies bound to 65... |
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