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6138401 | Protective mechanism of beta-cyclodextrin for the hemolysis induced with phenothiazine neuroleptics in vitro. | beta-Cyclodextrin (beta-CyD) was found to protect the human erythrocytes from the hemolysis induced with ten phenothiazine neuroleptics in isotonic solution. The hemolytic activities of the phenothiazine-beta-CyD systems appeared to depend upon the free phenothiazine concentration, suggesting that the complexed form of... |
6224557 | Cyclodextrin glycosyltransferases from Klebsiella pneumoniae M 5 al and Bacillus macerans: quantitative analysis by high-performance liquid chromatography of the (1 leads to 4)-alpha-D-glucopyranosyl transfer-products from some linear and cyclic substrates. | The analysis of the (1 leads to 4)-alpha-D-glucopyranosyl transfer-products from some linear and cyclic substrates by quantitative h.p.l.c. illuminated the mode of action of the cyclodextrin glycosyltransferases [1 leads to 4)-alpha-D-glucan:[(1 leads to 4)-alpha-D-glucopyranosyl]transferase (cyclising), EC 2.4.1.19) f... |
6881766 | Correlation between chromatin morphology as derived by digital image analysis and autoradiographic labeling pattern. | In order to interpret the Feulgen-dependent chromatin morphology on a functional basis, we performed model experiments in which labeling with 14C-thymidine and 14C-uridine was used as a functional parameter. Using a relocation facility, information on either DNA or RNA, labeling intensity of a cell was added to the par... |
6192249 | Preparation of single molecules and supramolecular complexes for high-resolution metal shadowing. | We have compared the appearance and preservation of molecular and supramolecular structures in preparations that were dried in vacuo at room temperature or freeze-dried. Fibrinogen and brain spectrin molecules appear similar in both types of preparation provided that drying at room temperature is performed in the prese... |
6191834 | Is the knife-cut in the hypothalamus a permanent barrier to regrowth of nerve fibers? -an affirmative answer. | The regenerative capacity of nerve fibers was studied in adult female rats. Horseradish peroxidase was injected into the anterior hypothalamus lateral to the suprachiasmatic nucleus 4 days, 6 weeks and 4 months, respectively, following an archiform retrochiasmatic knife-cut. The trajectory of the stained fibers was exa... |
6871371 | Theory for modeling the copolymerization of tubulin and tubulin-colchicine complex. | Substoichiometric concentrations of tubulin-colchicine complex (TC) inhibits microtubule assembly through a copolymerization reaction between tubulin and TC. We have determined the rates and extent of TC incorporation into bovine brain microtubules and developed a theory that models copolymerization. Our analysis sugge... |
6307303 | The solvent polarity dependent conformational equilibrium of the carboxylic ionophore narasin: a proton NMR study. | Two dimensional homonuclear (1H-1H) chemical shift correlation, double resonance and nuclear Overhauser effect difference spectroscopy were used to determine spectral parameters of narasin acid in different solvents approximating the range of polarities encountered within a biological membrane. The observed chemical sh... |
6306572 | Reversible decatenation of kinetoplast DNA by a DNA topoisomerase from trypanosomatids. | DNA topoisomerase activity detected in cell extracts of the trypanosomatid Crithidia fasciculata interlocks kinetoplast DNA duplex minicircles into huge catenane forms resembling the natural kinetoplast DNA networks found in trypanosomes. Catenation of duplex DNA circles is reversible and equilibrium is affected by ion... |
6306567 | Clustered repeat sequences in the genome of Epstein Barr virus. | The genome of Epstein-Barr virus is composed of unique DNA interspersed with repetitive sequences. This organization suggests that Epstein-Barr virus provides a useful model for studying the function(s) of repetitive sequences in eukaryotic chromosomes. The primary structure of two of the repeat sequences, the 3072 bp ... |
6863544 | Molecular and functional changes in spectrin from patients with hereditary pyropoikilocytosis. | The structural and functional properties of spectrin from normal and hereditary pyropoikilocytosis (HPP) donors from the two unrelated families were studied. The structural domains of the spectrin molecule were generated by mild tryptic digestion and analyzed by two-dimensional electrophoresis (isoelectric focusing; so... |
6305694 | Epidermal growth factor-induced topoisomerase(s). Intracellular translocation and relation to DNA synthesis. | We have used epidermal growth factor (EGF) to investigate the relationship between eukaryotic topoisomerases and DNA synthesis. We found that EGF stimulates topoisomerase activity in human fibroblasts and Swiss/3T3 mouse fibroblasts. The first increase is seen in the cytoplasm, followed by increased activity in the nuc... |
6305198 | Characterization of the rat neutrophil formyl peptide chemotaxis receptor. | Numerous synthetic N-formylated peptides, believed to be the analogs of the naturally occurring initiating signal peptides produced by bacteria, are potent chemotactic agents for phagocytic cells in several species. The authors have characterized the receptor with moderately high affinity for the chemotactic peptide f-... |
6304352 | Transformation-defective Rous sarcoma virus mutants with altered p19 of the gag gene and their inhibitory effect on host cell growth. | Mutants (PH2010, PH2011, PH2012) of Rous sarcoma virus which have a growth-inhibitory effect on chicken embryo fibroblasts were isolated from a temperature-sensitive mutant of the Schmidt-Ruppin strain of Rous sarcoma virus (tsNY68). The growth rate of fibroblasts infected with these viruses was about 50 to 60% of that... |
6406686 | Virus receptor interaction in the adenovirus system. II. Capping and cooperative binding of virions on HeLa cells. | Adenovirus type 2 attachment to HeLa cells was analyzed under controlled conditions. The temperature-dependent attachment kinetics revealed an inflection point at around 20 degrees C, and above this temperature the increase of the rate was doubled. In multiplicity dependence experiments, the attachment exhibited positi... |
6343400 | Association of microtubule-associated protein 2 (MAP 2) with microtubules and intermediate filaments in cultured brain cells. | The classification of MAP 2 as a microtubule-associated protein is based on its affinity for microtubules in vitro and its filamentous distribution in cultured cells. We sought to determine whether MAP 2 is also able to bind in situ to organelles other than microtubules. For this purpose, primary cultures of rat brain ... |
6343353 | Spatial differentiation in photosynthetic and non-photosynthetic membranes of Rhodopseudomonas palustris. | The cytoplasmic membrane and the photosynthetic intracytoplasmic membranes of Rhodopseudomonas palustris are spatially differentiated into regions of extremely high intramembrane-particle density (4,400 to 9,800/micron 2) and areas of lower intramembrane-particle density (2,700 to 5,900/micron 2). The high intramembran... |
6411065 | UDP-glucuronosyltransferase activity and bilirubin conjugation in the bullfrog. | Bile pigments of bile and serum of Rana catesbeiana were investigated by means of high-pressure liquid chromatography. The major pigment in both bile and serum was bilirubin IX alpha. Bilirubin UDP-glucuronosyltransferase activity was found in the livers of all animals examined, but no conjugated bilirubin was detectab... |
6875391 | Effect of cyclodextrins on the solubilization of lignoceric acid, ceramide, and cerebroside, and on the enzymatic reactions involving these compounds. | alpha-Cyclodextrin at concentrations of 1-8 mM helps dissolve, in aqueous solution, fatty acids such as lignoceric, stearic, and palmitic, and complex lipids such as ceramide and cerebroside that contain these acids. Formation of an inclusion complex was indicated on examination of the solution by gel filtration. alpha... |
6409095 | Wild-type and mutant forms of the pyruvate dehydrogenase multienzyme complex from Bacillus subtilis. | A simple procedure is described for the purification of the pyruvate dehydrogenase complex and dihydrolipoamide dehydrogenase from Bacillus subtilis. The method is rapid and applicable to small quantities of bacterial cells. The purified pyruvate dehydrogenase complex (s0(20),w = 73S) comprises multiple copies of four ... |
6306047 | Heptakis(2,6-O-dimethyl)beta-cyclodextrin: a novel growth stimulant for Bordetella pertussis phase I. | The effect of cyclodextrins on the growth of Bordetella pertussis Tohama phase I in synthetic medium was evaluated. The addition of cyclodextrins, especially heptakis(2,6-O-dimethyl)beta-cyclodextrin (Me beta CD), to a complete synthetic medium such as Stainer-Scholte medium gave the same number of individual colonies ... |
6304657 | Biochemical characterization of topoisomerase I purified from avian erythrocytes. | A type I topoisomerase has been purified from avian erythrocyte nuclei. The most pure fraction contains one major polypeptide of Mr = 105,000 (80% of total) and several minor ones of lower molecular weight. Active forms of the topoisomerase were identified by covalently binding the enzyme to 32P-DNA, digesting with nuc... |
6304617 | Positively supercoiled plasmid DNA is produced by treatment of Escherichia coli with DNA gyrase inhibitors. | A procedure has been developed whereby the relative amounts of the topoisomers of E. coli plasmid can be determined for cells grown under a variety of conditions. Several applications of the procedure are presented. Addition of either novobiocin or oxolinic acid, two inhibitors of DNA gyrase, gives rise to positively s... |
6189939 | Cytolysis by H-2-specific T killer cells. Assembly of tubular complexes on target membranes. | Cloned T killer cells derived from one-way mixed lymphocyte reactions were characterized with regard to their Lyt phenotype and specificity. Two clones of Lyt-1-2+ phenotype that recognized H-2Dd were selected and examined for their cytolytic function by negative staining and thin section electron microscopy. When incu... |
6222038 | Supramolecular regulation of the actin-activated ATPase activity of filaments of Acanthamoeba Myosin II. | Acanthamoeba myosin II has three phosphorylation sites clustered near the end of the tail of each of its two heavy chains (six phosphorylation sites/molecule). Myosin II has little or no actin-activated ATPase activity when four to six of these sites are phosphorylated. Maximal actin-activated ATPase activity is obtain... |
6687811 | Further studies on superoxide dismutase activities of macrocyclic polyamine complexes of copper(II). | The superoxide dismutase (EC 1.15.1.1) activities of new series of macrocyclic complexes with copper(II) have been measured. Chemical modifications in macrocyclic ring size, donor atom, donor atom number, substituents on the macrocyclic skeletons, and length of bridges linking two macrocycles are shown to have profound... |
6221342 | Mutations in lambda repressor's amino-terminal domain: implications for protein stability and DNA binding. | The DNA binding properties of 52 different single-amino acid substitutions in lambda repressor's amino-terminal domain have been characterized. Seven proteins bearing mutations that change solvent-exposed side chains have been purified. The amino-terminal domains of these mutant repressors are folded and are comparable... |
6404884 | Transport and localization of protein S, a spore coat protein, during fruiting body formation by Myxococcus xanthus. | Protein S, the most abundant soluble protein synthesized by Myxococcus xanthus FB during early fruiting body formation, accumulates in the soluble fraction of developing cells, reaching a peak at about 24 h; at late stages of fruiting body formation, protein S is found on the surface of spores (M. Inouye et al. Proc. N... |
6135605 | Oral contraceptive steroids as promoters or complete carcinogens for liver in female Sprague-Dawley rats. | Published reports have described an increased incidence of adenomas and of hepatocellular carcinomas in livers of women with a history of long-term oral contraceptive use. Evidence derived from human and experimental animals suggests that oral contraceptive steroids may be liver tumor promoters. Experiments were design... |
6864476 | Stability constants for complex formation between alpha-cyclodextrin and some amines. | Complex formation of alpha-cyclodextrin with 15 amines (including seven 4-substituted anilines) was studied by the potentiometric method, supplemented by direct UV spectrophotometry and a competitive indicator spectrophotometric method. The data were analyzed in terms of 1:1 and 1:2 complexes (amine-cyclodextrin ratios... |
6190798 | Difference spectroscopic study of the interaction between soybean beta-amylase and substrate or substrate analogues. | 1. In order to investigate the interactions between soybean beta-amylase [EC 3.2.1.2] and ligands (maltotriose as substrate, and maltose and alpha- and beta-cyclodextrins as inhibitors for the hydrolysis of maltoheptaose), the difference spectra were measured at 25 degrees C and pH 5.4, in 0.05 M acetate buffer. Each d... |
6860659 | Molecular flexibility in microtubule proteins: proton nuclear magnetic resonance characterization. | Bovine microtubule protein preparations have been examined by proton nuclear magnetic resonance (1H NMR) spectroscopy at 270 MHz. Sharp resonances have been identified as deriving from microtubule-associated proteins. These resonances persist after self-assembly of microtubule protein. Brief tryptic treatment of assemb... |
6190074 | Tissue specificity of epithelial keratins: differential expression of mRNAs from two multigene families. | Human epithelial cells cultured from stratified and simple squamous tissues all produce keratins of 40,000 to 58,000 daltons, but within this range the number and sizes vary with different epithelial cells. We have shown that this tissue-specific variation in the keratins is not due to posttranslational modification or... |
6301692 | Site-specific relaxation and recombination by the Tn3 resolvase: recognition of the DNA path between oriented res sites. | We studied the dynamics of site-specific recombination by the resolvase encoded by the Escherichia coli transposon Tn3. The pure enzyme recombined supercoiled plasmids containing two directly repeated recombination sites, called res sites. Resolvase is the first strictly site-specific topoisomerase. It relaxed only pla... |
6300891 | beta-Carbolines enhance shock-induced suppression of drinking in rats. | By using Vogel's method to test the anxiolytic action of benzodiazepines and reducing the intensity of the current delivered to the drinking tube, it is possible to distinguish the pharmacological activity of three types of ligands for the benzodiazepine recognition site. An anticonflict action typical of anxiolytic be... |
6572956 | Modular structural units, exons, and function in chicken lysozyme. | By the application of the same algorithm for finding compact structural units encoded by exons as applied previously to hemoglobin, five units, M1-M5, were identified in chicken egg white lysozyme. They consist of residues 1-30, 31-55, 56-84, 85-108, and 109-129, respectively. I call these compact structural units "mod... |
6572947 | 5S rRNA gene transcription factor IIIA alters the helical configuration of DNA. | Relaxation of Xenopus 5S plasmid DNA (pX1o8) in the presence of transcription factor (TF) IIIA reduces the linking number of the DNA. Parallel experiments with plasmid pMB9 or cloned hepatitis B viral DNA indicate a degree of non-specific unwinding by TF; however, 60% of the effect observed for pX1o8 is due to specific... |
6833395 | Production of monoclonal antibodies against calmodulin by in vitro immunization of spleen cells. | Monoclonal antibodies against the highly conserved ubiquitous calcium-binding protein, calmodulin (CaM), were produced by immunization of mouse primary spleen cell cultures. Dissociated spleen cells were cultured for 5 d in the presence of mixed thymocyte culture conditioned media (TCM) and purified bovine testes CaM (... |
6402605 | Bacteriophage SPO1 structure and morphogenesis. I. Tail structure and length regulation. | Bacteriophage SPO1, a structually complex phage with hydroxymethyl uracil replacing thymine, has been studied by structural and chemical methods with the aim of defining the virion organization. The contractile tail of SPO1 consists of a complex baseplate, a tail tube, and a 140-nm-long sheath composed of stacked disks... |
18638938 | The self-assembly of the cowpea strain of southern bean mosaic virus: formation of T = 1 and T = 3 nucleoprotein particles. | Virion-like particles of the cowpea strain of southern bean mosaic virus were assembled from isolated coat protein and RNA components in vitro at low ionic strength. Purified southern bean mosaic virus RNA was heterogeneous on sucrose gradients, and was separated into low (0.3 - 0.6 x 10(6) Da) and high (1.0-1.4 x 10(6... |
17246121 | Adaptation at Specific Loci. II. Demographic and Biochemical Elements in the Maintenance of the Colias Pgi Polymorphism. | Demographically oriented sampling in the wild and biochemical study of allozymes in the laboratory have been used to probe maintenance of the phosphoglucose isomerase polymorphism of Colias butterflies.-The several alleles at this locus show negative or no covariation among their frequencies in the wild. This rules out... |
6876829 | Biophysical studies on molecular mechanisms of abortifacient action of prostaglandins. V. CNDO/2 estimation of the relative affinities of the cations Na+, Mg2+ and Ca2+ to the carboxylic group. | The paper describes the study of relative affinities of the cations Na+, Mg2+ and Ca2+ to the carboxylic group, their electronic structure and optimum binding positions on the basis of the CNDO/2 technique, using the well known supramolecular approach. The cation for this purpose was made to approach the carboxylic gro... |
6870789 | Molecular composition of the terminal membrane and fluid-phase C5b-9 complexes of rabbit complement. Absence of disulphide-bonded C9 dimers in the membrane complex. | The terminal membrane C5b-9(m) and fluid-phase SC5b-9 complexes of rabbit complement were isolated from target sheep erythrocyte membranes and from inulin-activated rabbit serum respectively. In the electron microscope, rabbit C5b-9(m) was observed as a hollow protein cylinder, a structure identical with that of human ... |
6867080 | Preparation, properties and biological activity of beta-cyclodextrin inclusion complex of menadione. | The molar ratio of menadione (vitamin K3) to beta-cyclodextrin in the microcrystalline inclusion complex showed this to be 1:3 with a menadione content of approximately 4.1-4.3%. Complexes with higher vitamin content could not be prepared. Bound and free vitamin can be readily separated by sublimation in vacuum. The me... |
6304555 | On the mode of action of imipramine: relationship between serotonergic axon terminal function and down-regulation of beta-adrenergic receptors. | Recognition sites for [3H]imipramine and [3H]mianserin are located in different structures and regulate different neuronal functions. Recognition sites for [3H]imipramine are located on serotonergic terminals, are part of the supramolecular organization of the uptake mechanisms and can be down-regulated by prolonged ad... |
6852063 | Supramolecular forms of actin induced by polyamines; an electron microscopic study. | Electron microscopy of negatively stained samples shows that spermine and spermidine induce the polymerization of G-actin into filaments and paracrystalline bundles. In the presence of low concentrations of polyamines (0.02 mM spermine or 0.2 mM spermidine), filaments resembling salt-induced F-actin were observed, but ... |
6303210 | Inhibition of herpes simplex virus DNA synthesis by pokeweed antiviral protein. | Pokeweed antiviral protein at a concentration of 3 microM inhibited both the synthesis and release of infectious herpes simplex virus type 1 in cell culture by 90 and 99%, respectively. Addition of pokeweed antiviral protein to Vero cell monolayers before virus infection was 10 to 15% more effective in reducing virus y... |
6842602 | Self-assembly of brome mosaic virus capsids. Kinetic study using neutron and X-ray solution scattering. | The self-assembly of brome mosaic virus capsid has been studied kinetically by means of X-ray and neutron scattering. It appears to be a very fast process: for the concentrations used (5 to 8 mg/ml) the forward scattering reaches 50% of its maximal value in less than one second. Further, the assembly seems to proceed t... |
6842600 | Self-assembly of brome mosaic virus protein into capsids. Initial and final states of aggregation. | The pH and ionic strength dependence of the states of aggregation of brome mosaic virus protein has been investigated by small angle neutron scattering, quasielastic light-scattering, analytical centrifugation and electron microscopy. At pH above neutrality, protein oligomers are found in dynamical equilibrium, compris... |
6341233 | Association of elevated levels of cellular lipoteichoic acids of group B streptococci with human neonatal disease. | Cell-associated lipoteichoic acids (LTAs) from late-exponential-phase cultures (serotypes Ia, Ib, Ic, II, and III) of group B streptococci isolated from infected and asymptomatically colonized infants were quantitated and characterized by growing the organisms in a chemically defined medium containing [3H]glycerol and ... |
6838200 | Proteoglycans from the substratum adhesion sites of MSV-transformed BALB/c 3T3 cells. | Kirsten murine sarcoma virus-transformed Balb/c 3T3 cells (KiMSV) are highly tumorigenic and metastatic in the appropriate murine host, are loosely adherent to the tissue culture substratum, and can be readily detached from the substratum by ethylene glycol bis(beta-aminoethyl ether) N,N'-tetraacetic acid treatment lea... |
6572937 | Immunocytochemical localization of actin and microtubule-associated protein MAP2 in dendritic spines. | To determine whether dendritic spines contain actin, we evaluated the immunocytochemical localization of actin in the hippocampal formation and cerebral cortex of the rat. Monoclonal hybridoma antibodies were prepared against adult quail breast muscle actin. The culture supernatant of two cell lines (QAB1 and QAB2) was... |
6682113 | Filopodelike projections induced with dimethyl sulfoxide and their relevance to cellular polarity in Dictyostelium. | When 5% dimethyl sulfoxide (DMSO) was applied to Dictyostelium cells, the cells rounded up in shape and cytoplasmic streaming ceased. The cells resumed both cytoplasmic streaming and locomotion in 20 min. SDS PAGE of isolated plasma membrane fractions showed that actin and myosin apparently became dissociated from the ... |
6300045 | (Na+ + K+)-dependent adenosine triphosphatase. Regulation of inorganic phosphate, magnesium ion, and calcium ion interactions with the enzyme by ouabain. | 1. (Na+ + K+)-dependent adenosine triphosphatase was phosphorylated on the alpha-subunit by Pi in the presence of Mg2+. Phosphorylation was stimulated by ouabain. The interactions of Pi, Mg2+, and ouabain with the enzyme could be explained by a random terreactant scheme in which the binding of each ligand to the enzyme... |
6402495 | Developmental cell interactions of Myxococcus xanthus: analysis of mutants. | A set of developmental mutants have been examined that behave as if defective in cellular interactions necessary for the formation of myxospores during fruiting body development. Sporulation is rescued in these mutants if they are mixed with wild-type cells. Complementation experiments with whole cells divide the mutan... |
6230421 | Methyl-CCNU, 5-fluorouracil, vincristine, and streptozocin (MOF-STREP) in metastatic colo-rectal carcinoma. | Forty patients with metastatic colorectal carcinoma who had received no prior chemotherapy were entered onto a trial of methyl-CCNU, 5-fluorouracil, vincristine, and streptozocin (MOF-STREP). Ten of 40 (25%) responded. Two patients (5%) achieved a complete response and eight patients (20%) a partial response. In additi... |
6864436 | Improvement of oral bioavailability of prednisolone by beta-cyclodextrin complexation in humans. | Inclusion complex of prednisolone with beta-cyclodextrin (beta-CyD) in 1:2 molar ratio was prepared and its dissolution, membrane permeation and oral absorption behaviors were examined. The rates of dissolution and permeation through a cellophane membrane in water were significantly increased by beta-CyD complexation. ... |
6222730 | Alteration of sarcoplasmic reticulum after denervation of chicken pectoralis muscle. | To determine the neural influence on the function of the sarcoplasmic reticulum (SR) of fast-twitch skeletal muscle, the superior pectoralis muscle of adult chicken was denervated, and the SR was isolated at 20 days post-denervation. The isolated SR was probably derived from the longitudinal SR and was relatively free ... |
6304788 | Improvement of the absorption of 3H-Cholecalciferol by formation of its cyclodextrin complex. | Following oral administration to rats of beta-cyclodextrin inclusion complex of 3H-labelled vitamin D3 (cholecalciferol) resulted in significantly higher blood radioactivity as with the non-complexed vitamin. Difference in the first 90 min was 2,3-2,8 fold, and it remained significantly higher up to the 6th h. After 24... |
6847635 | High-performance liquid chromatography of coproporphyrin isomers. | A reversed-phase system is described for the simultaneous isocratic separation of coproporphyrin I, II, III and IV isomers. The retention behaviour of coproporphyrin I and III is studied in detail. The method is suitable for both analytical and semi-preparative separation. |
6341989 | Isolation and characterization of the plasma membrane of human erythrocytes infected with the malarial parasite Plasmodium falciparum. | Human erythrocytes infected with the malarial parasite Plasmodium falciparum were labeled metabolically with a mixture of 15 radioactive amino acids. When synchronously growing parasites were at the schizont stage of development infected cells were concentrated and purified by using a Percoll-Hypaque gradient. The plas... |
6300655 | Two classes of mutant mammary tumor virus-infected HTC cell with defects in glucocorticoid-regulated gene expression. | We have isolated mutant derivatives of M1.54 (a mammary tumor virus [MTV]-infected rat hepatoma [HTC] cell line containing multiple integrated proviruses) that fail to express hormone-inducible cell surface viral glycoproteins. In wild-type M1.54, the synthetic glucocorticoid dexamethasone selectively stimulates the ra... |
6300437 | Isolation and characterization of a membrane-bound population of group B coxsackieviruses. | HeLa cells infected with several group B coxsackieviruses contain a previously undetected, virus-specific ribonucleoprotein particle which we designated membrane-bound virion (MBV). MBVs of B5 virus have a pronounced polygonal appearance and are slightly smaller than virions. The particles sediment more slowly (at abou... |
6187936 | Mechanism of action of the endonuclease associated with the alpha beta and beta beta forms of avian RNA tumor virus reverse transcriptase. | Preparations of the alphabeta and the betabeta forms of reverse transcriptase from the Prague C strain of Rous sarcoma virus grown in chicken embryo fibroblasts, the alphabeta and the betabeta forms of the enzyme from the B77 strain of Rous sarcoma virus grown in duck embryo fibroblasts, and the alphabeta form of rever... |
6339736 | UC-1, a new bacteriophage that uses the tonA polypeptide as its receptor. | We characterized UC-1, a previously undescribed Escherichia coli phage. UC-1 was observed to have an icosahedral head and a long, flexible, noncontractile tail: its genome consisted of linear double-stranded DNA having a molecular weight of 34 X 10(6). The product of the tonA gene served as at least part of the recepto... |
6300417 | Self-assembly of simian virus 40 large T antigen oligomers by divalent cations. | In simian virus 40-transformed cells, simian virus 40 large T antigen can be detected in different forms separable by sucrose density gradient centrifugation. In our experiments, light forms sedimented around 5 to 7S, oligomers such as tetramers were detected around 16S, and higher aggregates sedimented in a broad dist... |
6298730 | DNA topoisomerases from rat liver: physiological variations. | Besides the nicking-closing (topoisomerase I) activity, an ATP-dependent DNA topoisomerase is present in rat liver nuclei. The enzyme, partially purified, is able to catenate in vitro closed DNA circles in a magnesium-dependent, ATP-dependent, histone H1-dependent reaction, and to decatenate in vitro kinetoplast DNA ne... |
6822545 | The fate of an N-formylated chemotactic peptide in stimulated human granulocytes. Subcellular fractionation studies. | Experiments were performed to examine how human granulocytes process the chemotactic peptide N-formyl-Met-Leu-Phe after stimulation by the same peptide. Purified human granulocytes were stimulated with 50 nM N-formyl-Met-Leu-[3H]Phe at 37 degrees C for various times, washed, lysed by N2 cavitation, and fractionated by ... |
6130060 | Properties of pili from Escherichia coli SS142 that mediate mannose-resistant adhesion to mammalian cells. | We isolated pili from Escherichia coli SS142. These pili had a diameter of 6 nm and an average length of 400 nm. They were composed of subunits with a molecular weight of 18,000. Their amino acid composition was determined; methionine and proline were not detected. The isolated pili retained mannose-resistant hemagglut... |
6218154 | Identification and localization of enzymes of the fumarate reductase and nitrate respiration systems of escherichia coli by crossed immunoelectrophoresis. | Crossed immunoelectrophoresis was used to analyze the components of membrane vesicles of anaerobically grown Escherichia coli. The number of precipitation lines in the crossed immunoelectrophoresis patterns of membrane vesicles isolated from E. coli grown anaerobically on glucose plus nitrate and on glycerol plus fumar... |
24407339 | Synthesis of (±)-disparlure. | A six-step, convergent synthesis has been developed for racemic (Z)-7,8-epoxy-2-methyloctadecane (disparlure), the sex pheromone of the gypsy moth. The key step is a Wittig reaction between 6-methylheptanal and triphenylundecylphosphonium bromide effected by potassium carbonate in the presence of a crown ether. |
16662839 | Structure of the Thylakoids and Envelope Membranes of the Cyanelles of Cyanophora paradoxa. | The cyanelles of Cyanophora paradoxa Korsch. are photosynthetically active obligate endosymbionts in which phycobiliproteins serve as the major accessory pigments. Freeze-fracture electron micrographs of thylakoids in isolated cyanelles reveal long parallel rows of particles covering most of the E-face, while a more ra... |
16578766 | Localization of different photosystems in separate regions of chloroplast membranes. | The stoichiometric amounts and the photoactivity kinetics of photosystem I (PSI) and of the alpha and beta components of photosystem II (PSII(alpha) and PSII(beta)) were compared in spinach chloroplast membrane (thylakoid) fractions derived from appressed and nonappressed regions. Stroma-exposed thylakoid fractions fro... |
6361518 | Chlorophyll a biosynthetic routes and chlorophyll a chemical heterogeneity in plants. | A six-branched chlorophyll a biosynthetic pathway instead of a four-branched pathway has been proposed as being responsible for the formation of chlorophyll a in green plants. The several biosynthetic routes that make up the pathway have been described as leading to the formation of ten chemically different groups of c... |
6317597 | Biochemical and electrophysiological characteristics of mammalian GABA receptors. | The concept that GABA is a neurotransmitter in the mammalian CNS is supported by both electrophysiological and biochemical data. Whereas the electrophysiological studies are essential for demonstrating a specific functional response to GABA, the biochemical approach is useful for characterizing the molecular properties... |
6685624 | Amino acid sequence data on glial fibrillary acidic protein (GFA); implications for the subdivision of intermediate filaments into epithelial and non-epithelial members. | Determination of 50% of the sequence of the astrocyte-specific intermediate filament (IF) protein documents the hypervariable regions as well as parts of the coiled-coil array of glial fibrillary acidic protein (GFA). The results show that the four non-epithelial IF proteins (myogenic desmin, mesenchymal vimentin, GFA ... |
6314214 | Haloxon-induced delayed neurotoxicity: effect of plasma A (aryl) esterase activity on severity of lesions in sheep. | A markedly different response to the delayed neurotoxic effects of a single dose of 400 or 800 mg/kg of the organophosphorus anthelmintic haloxon was observed in two populations of sheep. Animals with a gentically determined low level of activity of the plasma enzyme A (aryl) esterase developed clinical signs of delaye... |
6414336 | Ontogenetic development of TRH-like immunoreactive nerve terminals in the median eminence of the rat. | Ontogenetic development of TRH-like immunoreactive nerve terminals in the median eminence of the rat was studied immunocytochemically. By light microscopy, TRH-like immunoreactivities were first detected on the 1st day after birth in the external layer of the median eminence. By electron microscopy, TRH-like immunoreac... |
6612711 | The infrastructure of aortic elastic fibers. | Elastic fibers are composed of a central core of elastin that is amorphous and electron-lucent in conventional transmission electron micrographs and peripheral microfibrils. A complex infrastructure within the amorphous elastin of mature rat aorta is made visible by fixation and staining with a glutaraldehyde-ruthenium... |
6868855 | [Multiple organ failure--the most important complication in polytraumatized patients]. | In 4 1/2 years 78 out of 433 polytrauma-patients came to death in our hospital ( = 18%), half of them because of their brain-trauma. 15 fatalities occurred in connection with pulmonary failure only, 19 in multiple organ failure. Pulmonary failure is of central importance in MOF. Two types of MOF are described: the rapi... |
6868149 | [Inhibitor of fibrin self-assembly]. | The thermostable inhibitor with a molecular mass 1750 +/- 100 was found in human, bovine and albino rat blood sera. A ninhydrin-positive product containing no carbohydrates, lipids, nucleic acids was obtained while purifying the inhibitor by combining column ion-exchange chromatography and partition thin layer chromato... |
6868148 | [Analysis of the stability of the intermediate fibrin polymers formed in a fibrinogen-thrombin system]. | Intermediate fibrin polymers formed from fibrinogen at low thrombin concentrations under physiological conditions are studied for their stability. Smith's statement that intermediate fibrin oligomers are inert molecules whose further self-assembly is possible only under additional thrombin activation was not supported.... |
6342608 | The Wrb antigen, a receptor for Plasmodium falciparum malaria, is located on a helical region of the major membrane sialoglycoprotein of human red blood cells. | 1. Immunoprecipitation of periodate/NaB3H4-labelled human erythrocytes using anti-Wrightb (Wrb) monoclonal antibodies showed that these antibodies specifically react with the major erythrocyte sialoglycoprotein alpha (glycophorin A). 2. Similar experiments on erythrocytes from the only known individual lacking the Wrb ... |
6847610 | The enzyme-activated irreversible inhibition of type-B monoamine oxidase by 3-(4-[(3-chlorophenyl)methoxy]phenyl)-5-[(methylamino) methyl]-2-oxazolidinone methanesulphonate (compound MD 780236) and the enzyme-catalysed oxidation of this compound as competing reactions. | 3-(4-[(3-Chlorophenyl)methoxy]phenyl)-5-[(methylamino)methyl]-2- oxazolidinone methanesulphonate (compound MD 780236) is a selective inhibitor of the B-form of monoamine oxidase. Inhibition involves an initial non-covalent interaction between enzyme and inhibitor followed by a time-dependent process resulting in irreve... |
6552184 | Medium-chain fatty acid synthesis by goat mammary-gland fatty acid synthetase. The effect of limited proteolysis. | Fatty acid synthetase from goat mammary gland was subjected to limited proteolysis by trypsin and elastase. Both proteolytic enzymes selectively cleaved the chain-terminating thioester hydrolase component from the enzyme complex, leaving all other partial activities intact in the core peptides. Trypsin, but not elastas... |
6847606 | Heterogeneity of rat goblet-cell mucin before and after reduction. | Goblet-cell mucin of rat small intestine was purified from mucosal scrapings by using centrifugation, Sepharose 4B and Sepharose 2B chromatography. The mucin was applied in low concentrations (1 microgram/track) to slab gels containing 0.5% agarose/2% (w/v) polyacrylamide, and bands were detected after electrophoresis ... |
6342473 | Immunohistochemical demonstration of serotonin nerve fibers in the neocortex of the monkey (Macaca fuscata). | Using a peroxidase-antiperoxidase immunohistochemical method, the distribution of serotonin nerve fibers was studied in the neocortex of the monkey (Macaca fuscata). All layers of the neocortex showed evidence of serotonin fibers, both fine and thick. Unlike the distribution in rodents, different patterns of distributi... |
6842120 | Posttranscriptional block to synthesis of a human adenovirus capsid protein in abortively infected monkey cells. | The synthesis of fiber protein in CV1 (monkey) cells abortively infected with human adenovirus serotype 2 (Ad2) is at least 100-fold less than the synthesis of fiber protein in CV1 cells productively infected with a host range mutant of Ad2 (Ad2hr400) or coinfected with Ad2 plus simian virus 40. However, the amount of ... |
6841142 | Enhanced membrane fluorescence of CDC-labelled paramecium subsequent to removal of surface components. | Cytofluorimetric analysis of cycloheptaamylose-dansyl chloride (CDC) labelled Paramecium indicates that after mild trypsin removal of surface components the localization of CDC on the outer surface of living cells was not modified by the treatment. After such treatment the intensity of fluorescence emission was found a... |
6572899 | Effect of titration charge on the diffusion of bovine serum albumin. | Quasi-elastic light scattering studies were performed on purified bovine serum albumin sample under conditions of high and low ionic strength and pH. Two relaxation modes were observed in all cases. The apparent diffusion coefficient obtained in the asymptotic time window (T) limit T leads to 0-i.e., Dapp(T leads to 0)... |
6187599 | Mobilization of maternal mRNA in amphibian eggs with special reference to the possible role of membraneous supramolecular structures. | Current knowledge of the mechanism of mobilization of maternal mRNA is summarized herein and a working hypothesis has been constructed to explain the mechanism on the assumption that the mRNA enters the cytoplasm in association with the cytoplasmic membraneous structures and is then stored in the structures until liber... |
6298603 | In vivo catenation and decatenation of DNA. | We have noted previously that when circular, but not linear, DNA or chromatin was injected into Xenopus laevis oocytes, much of it went through an intermediate form in which it did not readily enter an agarose gel; after a few hours, it reappeared as monomer DNA that had acquired its full complement of nucleosomes (T. ... |
6826654 | Architecture of metaphase chromosomes and chromosome scaffolds. | We have developed procedures for depositing intact mitotic chromosomes and isolated residual scaffolds on electron microscope grids at controlled and reproducible levels of compaction. The chromosomes were isolated using a recently developed aqueous method. Our study has addressed two different aspects of chromosome st... |
6186670 | Monoclonal antibodies against chicken type V collagen: production, specificity, and use for immunocytochemical localization in embryonic cornea and other organs. | Two monoclonal antibodies have been produced against chick type V collagen and shown to be highly specific for separate, conformational dependent determinants within this molecule. When used for immunocytochemical tissue localization, these antibodies show that a major site for the in situ deposition of type V is withi... |
6824497 | Age-related changes in composition and mechanical properties of the tunica media of the upper thoracic human aorta. | A cylindrical segment, free of complex atherosclerotic lesions, was resected at autopsy from each of 59 descending human thoracic aortas by cutting just below the level of the first pair of intercostal arteries and 35 mm distal to this incision. Each isolated tunica media was defatted and subjected to successive treatm... |
6824315 | Serological method for identification of Vibrio parahaemolyticus from marine samples. | Use of agglutination with antiserum against lateral flagella (H-agglutination) for the identification of Vibrio parahaemolyticus was studied. Sucrose-negative bacteria were isolated from seawater, and their characterization was carried out by traditional biological tests and slide agglutination with antiserum specific ... |
6296439 | Improved localization of phosphorylation sites in simian virus 40 large T antigen. | The location of phosphorylation sites in the large T antigen of simian virus 40 has been studied both by partial chemical cleavage and by partial proteolysis of various forms of large T. These included the full-size wild-type molecule with an apparent molecular weight of 88,000, deleted molecules coded for by the mutan... |
6337102 | Monoclonal antibodies to Trypanosoma cruzi inhibit motility and nucleic acid synthesis of culture forms. | Monoclonal antibodies were raised against the surface of epimastigotes and metacylic trypomastigotes of Trypanosoma cruzi, as shown by electron microscopy, agglutination, and immunofluorescence. The antibodies were stage specific but not strain specific. A deleterious effect of the antibodies on T. cruzi culture forms ... |
6822416 | Concentration-dependent multiple binding sites on saliva-treated hydroxyapatite for Streptococcus sanguis. | The influence of bacterial cell concentration on estimates of the number of binding sites and the affinity for the adsorption of a strain of Streptococcus sanguis to saliva-treated hydroxyapatite was determined, and the possible presence of multiple binding sites for this organism was tested. The range of concentration... |
6217886 | Metastatic colorectal carcinoma. A prospective randomized trial of Methyl-CCNU, 5-Fluorouracil (5-FU) and vincristine (MOF) versus MOF plus streptozotocin (MOF-Strep). | A prospective randomized trial evaluated semustine (Methyl CCNU) 5-Fluorouracil (5-FU) and vincristine (MOF) versus MOF plus streptozotocin (MOF-Strep) in 75 patients with advanced, measurable colorectal carcinoma. The complete and partial remission rate with MOF-Strep was significantly better, 34 versus 5% with MOF (P... |
6600266 | Stages of renal ontogenesis identified by monoclonal antibodies reactive with lymphohemopoietic differentiation antigens. | Differentiation antigens of T and B lymphocytes were sought in human fetal and adult kidney tissues with monoclonal antibodies by indirect immunofluorescence. Antibodies that identify B cells (BA-1 and anti-B1) and leukemia-associated antigens (BA-2, BA-3, and J5) reacted with renal glomerular and tubular epithelium at... |
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