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2180374 | Isolation of Candida albicans and halophilic Vibrio spp. from aquatic birds in Connecticut and Florida. | Halophilic vibrios were recovered from feces of six types of aquatic birds (gulls, pelicans, Canada geese, swans, egrets, cormorants) from Connecticut and/or Florida shorelines. Candida albicans was isolated from gulls and Canada geese in Connecticut and from gulls and cormorants in Florida. |
2314462 | Relative helix-forming tendencies of nonpolar amino acids. | An important issue in understanding the relationship between protein sequence and structure is the degree to which different amino acids favour the formation of particular types of secondary structure. Estimates of the 'helix-forming tendency' of amino acids have been made based on 'host-guest' experiments, in which co... |
2311583 | Phosphorylation at clustered -Ser-Pro-X-Lys/Arg- motifs in sperm-specific histones H1 and H2B. | Sea urchin sperm-specific histones H1 and H2B have distinctive N-terminal, and in the case of H1 also C-terminal, domains containing repeats of a basic motif (-Ser-Pro-Lys/Arg-Lys/Arg- or a closely related sequence). The histones in spermatids (the precursors of sperm) are phosphorylated, and the unphosphorylated histo... |
2311226 | Flocculation of serum lipoproteins with cyclodextrins: application to assay of hyperlipidemic serum. | We describe the complexation of isolated and native lipoproteins by natural macrocyclic polymers of glucose ("cyclodextrins"). Treatment of serum with cyclodextrin produces an immediate flocculation of the lipoproteins. The formation of cyclodextrin-lipoprotein complexes was evident on agarose electrophoresis gels. The... |
1690026 | Isolation and characterization of gastric microsomal glycoproteins. Evidence for a glycosylated beta-subunit of the H+/K(+)-ATPase. | Detergent-solubilization of hog gastric microsomal membrane proteins followed by affinity chromatography using wheat germ agglutinin or Ricinus communis I agglutinin resulted in the isolation of five glycoproteins with the apparent molecular masses on sodium dodecyl sulfate polyacrylamide gels of (in kDa): 60-80 (two g... |
1968714 | Neurochemical and pharmacokinetic correlates of the clinical action of benzodiazepine hypnotic drugs. | Benzodiazepine derivatives are presumed to exert their pharmacologic activity via interaction with specific molecular recognition sites, termed benzodiazepine receptors, within the brain. The various benzodiazepines used in clinical practice differ considerably in their intrinsic receptor affinity, but the qualitative ... |
2307709 | Terminal short arm domains of basement membrane laminin are critical for its self-assembly. | Laminin self-assembles into large polymers by a cooperative two-step calcium-dependent mechanism (Yurchenco, P. D., E. C. Tsilibary, A. S. Charonis, and H. Furthmayr. 1985. J. Biol. Chem. 260:7636-7644). The domain specificity of this process was investigated using defined proteolytically generated fragments correspond... |
2307653 | Permeability barrier to hydrophilic solutes in Mycobacterium chelonei. | In order to define the permeability barrier to hydrophilic molecules in mycobacteria, we used as a model a smooth, beta-lactamase-producing strain of Mycobacterium chelonei. The rates of hydrolysis of eight cephalosporins by intact and sonicated cells were measured, and the permeability coefficient (P) was calculated f... |
1689716 | Hypoosmotic adaptation in Rhizobium meliloti requires beta-(1----2)-glucan. | beta-(1----2)-Glucan, an unusual cyclic oligosaccharide, can be isolated from the periplasm of bacteria belonging to the family Rhizobiaceae. Data presented here suggest that the periplasmic beta-(1----2)-glucan of Rhizobium meliloti plays a major role in osmotic adaptation. First, growth of R. meliloti in a low-osmola... |
2307647 | virG, an Agrobacterium tumefaciens transcriptional activator, initiates translation at a UUG codon and is a sequence-specific DNA-binding protein. | The Agrobacterium tumefaciens Ti plasmid virG locus, in conjunction with virA and acetosyringone, activates transcription of the virulence (vir) genes. Insertional and deoxyoligonucleotide-directed mutagenesis studies showed that both octopine and nopaline Ti plasmid virG genes initiate translation at a UUG codon. VirG... |
2407657 | Demonstration and immunochemical characterization of natural, autologous anti-idiotypic antibodies throughout the course of experimental syphilis. | Immunoglobulin Gs (IgGs) from serial bleeds obtained 1 week to 5 months after infection of rabbits with Treponema pallidum were examined for autologous anti-idiotypic (auto-anti-Id) antibodies. The capacities of IgGs to bind 125I-IgG F(ab')2 anti-T. pallidum prepared from earlier bleeds were determined by using radioim... |
2106490 | A recombinant Rickettsia conorii vaccine protects guinea pigs from experimental boutonneuse fever and Rocky Mountain spotted fever. | There are no vaccines against boutonneuse fever and Rocky Mountain spotted fever. Previous studies have identified a Rickettsia rickettsii surface protein as a vaccine candidate and shown that an antigenically related protein is present in R. conorii, which causes boutonneuse fever. The gene encoding the R. rickettsii ... |
2155181 | Comparison of the glycolipid receptor specificities of Shiga-like toxin type II and Shiga-like toxin type II variants. | The antigenically distinct Shiga-like toxins (SLTs) SLT-1 and SLT-II are cytotoxic for both Vero and HeLa cells and use Gal alpha 1-4Gal beta 1-4Glc beta 1-1Cer (Gb3) molecules as functional receptors. SLT-II-related variants SLT-IIvp and SLT-IIvh, produced by a porcine isolate and a human isolate, respectively, are cy... |
2307513 | Transmembrane diffusion channels in Mycoplasma gallisepticum induced by tetanolysin. | The permeability properties of Mycoplasma gallisepticum cells treated with a purified preparation of tetanolysin were investigated by determining the initial swelling rates of cells suspended in an isoosmotic solution of electrolytes or nonelectrolytes. The swelling, initiated by the tetanolysin, depended on the tetano... |
2407588 | Octamer transcription factors and the cell type-specificity of immunoglobulin gene expression. | Antibodies are produced exclusively in B lymphocytes. The expression of the antibody-encoding genes, the immunoglobulin (Ig) genes, is also restricted to B cells. The octamer sequence ATGCAAAT is present in the promoter and the enhancer of Ig genes, and plays an important role in its tissue-specific expression. This se... |
2307289 | Immunoelectron microscopy of type X collagen: supramolecular forms within embryonic chick cartilage. | To determine the supramolecular forms in which avian type X collagen molecules assemble within the matrix of hypertrophic cartilage, we performed immunoelectron microscopy with colloidal gold-labeled monoclonal antibodies. In addition double-labeled analyses were performed for the molecule and type II collagen, employi... |
1968105 | Sequence-specific DNA binding by the v-erbA oncogene protein of avian erythroblastosis virus. | The v-erbA oncogene, a transduced copy of a thyroid hormone receptor, plays an important role in establishment of the transformed cell phenotype induced by avian erythroblastosis virus. The ability of thyroid hormone receptors to bind to specific sites on chromatin and to thereby modify the expression of adjacent targe... |
2304143 | Protein kinase A-dependent binding of a nuclear factor to the 21-base-pair repeat of the human T-cell leukemia virus type I long terminal repeat. | The long terminal repeat (LTR) of the human T-cell leukemia virus type I (HTLV-I) contains an imperfect repeat of 21 nucleotides which governs the response to the virus trans-activator protein tax and to cyclic AMP. In a murine thymocyte cell line defective in the catalytic subunit of protein kinase A, the response of ... |
2303489 | Heparin modulation of laminin polymerization. | Previously, it has been shown that laminin will self-assemble by a two-step calcium-dependent process using end-domain interactions (Yurchenco, P. D., Tsi-library, E. C., Charonis, A. S., and Furthmayr, H. (1985) J. Biol. Chem. 260, 7636-7644). We now find that heparin, at low concentrations, modifies this polymerizati... |
1696133 | Immunological approach of assembly and topology of OmpF, an outer membrane protein of Escherichia coli. | Various monoclonal antibodies (MoF) directed against cell-surface-exposed epitopes of OmpF, one major outer membrane pore protein of Escherichia coli B and K-12, have been used to study the assembly and the topology of the protein. This paper firstly describes the characterization of the OmpF epitopes recognized by the... |
1366439 | Mechanism of the stimulatory effect of cyclodextrins on lankacidin-producing Streptomyces. | Gel-filtration analysis of a mixture of cyclodextrin (CyD) and lankacidin C showed that beta-CyD had strong, gamma-CyD weak and alpha-CyD no affinity for lankacidin C. Lankacidin C production activity, which was assayed by measuring the incorporation of L-[methyl-14C-]methionine into the lankacidin molecule, was the gr... |
2354064 | Sequence-selective, pH-dependent binding to DNA of benzophenanthridine alkaloids. | The sequence selectivity associated with binding to DNA of three alkaloids belonging to the benzophenanthridine family has been analysed by DNase I footprinting, and the results were compared with those obtained from an analysis of the behaviour of the standard intercalator, ethidium bromide. Like the ethidium, the ben... |
2354063 | The formation of mispairs by 8-oxyguanine as a pathway of mutations induced by irradiation and oxygen radicals. | Guanine conversion to 8-oxyguanine (OG) was induced by irradiation and oxygen radicals. The pathways of mutations caused by such DNA damage have been considered. Minima of interaction energies of OG with nucleic acid bases are revealed via classical potential function calculations. The minima exist for OG*:G and OG*:A ... |
2354062 | Interaction of the peptide CF3-Leu-Ala-NH-C6H4-CF3 (TFLA) with porcine pancreatic elastase. X-ray studies at 1.8 A. | The peptide trifluoroacetyl-Leu-Ala-(p-trifluoromethylanilide), is a reversible inhibitor of pancreatic porcine elastase and is characterized by a Km of 2.5 x 10(-8) M. Co-crystals of the 1:1 complex were obtained in an acetate buffer + dimethylformamide solution at pH 5.7. Diffraction data were recorded on films at th... |
2354061 | Molecular recognition between oligopeptides and nucleic acids. DNA sequence specificity and binding properties of an acridine-linked netropsin hybrid ligand. | The binding to DNA of a mixed function ligand (NETGA) is described, in which a potential intercalating group, an acridine moiety, is incorporated at the carboxyl terminus of the minor groove binding oligopeptide netropsin skeleton. Scatchard analysis of absorption data provided evidence of two modes of binding to DNA w... |
2191698 | Chemical and photochemical probing of DNA complexes. | An overview of the chemical and photochemical probes which over the past ten years have been used in studies of DNA/ligand complexes and of non-B-form DNA conformations is presented with emphasis on the chemical reactions of the probes with DNA and on their present 'use-profile'. The chemical probes include: dimethyl s... |
2344037 | Affinity of fibroblast growth factors for beta-cyclodextrin tetradecasulfate. | beta-Cyclodextrin tetradecasulfate was found to have a very strong affinity for fibroblast growth factor (FGF) and could substitute for heparin in FGF purification. Basic FGF was purified about 200,000-fold from a rat chondrosarcoma using a method of biaffinity chromatography in which the beta-cyclodextrin tetradecasul... |
2186485 | Structure of the extracellular matrix in normal and fibrotic liver: collagens and glycoproteins. | The sketches in Figures 11 and 12, necessarily simplified, summarize some of the points discussed in the previous paragraphs. It can be concluded that the hepatic ECM and the ECM in general is a complicated supramolecular assembly of numerous defined macromolecules, each of which is endowed with a specific potential fo... |
2159121 | DBI (diazepam binding inhibitor): the precursor of a family of endogenous modulators of GABAA receptor function. History, perspectives, and clinical implications. | Biochemical, electrophysiological, and lately, molecular biological techniques have shown that GABAA receptors are heterogeneous supramolecular complexes and can be divided into at least three major subgroups: GABAA1, GABAA2, and GABAA3. They differ mainly in the structural and functional properties of the allosteric m... |
2329144 | Separation and quantification by gas chromatography-mass spectrometry of arabinitol enantiomers to aid the differential diagnosis of disseminated candidiasis. | To differentiate increased arabinitol due to fungal (only D-arabinitol) and non-fungal origin, O-trifluoroacetyl derivatives of the enantiomers were separated using alpha-perpentylated cyclodextrin columns and measured by selected ion monitoring. Mean +/- S.D. D/L in normal serum: 1.40 +/- 0.42. D/L ratios greater than... |
2158373 | Characterisation of stereospecific binding sites for inositol 1,4,5-trisphosphate in airway smooth muscle. | 1. A 'P2' membrane fraction of bovine tracheal smooth muscle displays high affinity (KD 3.8 +/- 0.2 nM), saturable (Bmax 1003 +/- 170 fmol mg-1 protein) and reversible binding of D-myo[3H]-inositol 1,4,5-trisphosphate ([3H]-Ins(1,4,5)P3). 2. This binding site shows strict stereo- and positional specificity for the D-In... |
2324960 | Slow-release characteristics of diltiazem from ethylated beta-cyclodextrin complexes. | Release characteristics of two ethylated beta-cyclodextrins [heptakis(2,6-di-O-ethyl)-beta-cyclodextrin (diethyl-beta-cyclodextrin) and heptakis(2,3,6-tri-O-ethyl)-beta-cyclodextrin (triethyl-beta-cyclodextrin)] as sustained-release drug carriers were evaluated using diltiazem hydrochloride, a water-soluble calcium ant... |
1691260 | A comparative study of straight chain and branched chain fatty acid oxidation in skin fibroblasts from patients with peroxisomal disorders. | The beta-oxidation of stearic acid and of alpha- and gamma-methyl isoprenoid-derived fatty acids (pristanic and tetramethylheptadecanoic acids, respectively) was investigated in normal skin fibroblasts and in fibroblasts from patients with inherited defects in peroxisomal biogenesis. Stearic acid beta-oxidation by norm... |
1690576 | Optimizing and characterizing alignment of oriented lipid bilayers containing gramicidin D. | 31P NMR spectroscopy and optical microscopy have been used to characterize samples of gramicidin D in oriented lipid bilayers. Correlations have been made between the defect structures observed under crossed polarizers by optical microscopy and characteristic features of 31P NMR spectra. The sample preparation protocol... |
2156516 | Molecular recognition between oligopeptides and nucleic acids: DNA sequence specificity and binding properties of thiazole-lexitropsins incorporating the concepts of base site acceptance and avoidance. | The DNA binding and sequence specificity of a group of six novel thiazole containing lexitropsins related to the natural anti-tumor antibiotic distamycin have been examined by complementary strand MPE footprinting on two restriction fragments of pBR322 DNA. These lexitropsins comprise two groups in which the hetero ato... |
2311682 | Age-related changes in fibre differentiation of rat lens epithelial explants exposed to fibroblast growth factor. | Epithelial cells explanted from neonatal rat lenses undergo changes characteristic of fibre differentiation when cultured with neural retina, neural retina-conditioned medium (RCM), or acidic and basic fibroblast growth factor (FGF). In neonates fibre differentiation is marked by cell elongation, the accumulation of al... |
2309992 | [Organ failure in patients with multiple trauma. The effect of early osteosynthesis of fractures on complications]. | The course of 225 multiple traumatized patients in our ICU with a mean age of 35 +/- 16.8 years, a mean ISS of 30 +/- 8.3 and an overall mortality of 18.2% was evaluated retrospectively. For comparable ISS the mortality was higher in patients over 65 years, and increased further with age. The most common causes of deat... |
1968645 | The Croonian lecture, 1989. Antibodies: a paradigm for the biology of molecular recognition. | The hallmark of the antibody response to antigenic challenge is its remarkable specificity. In his Croonian Lecture in 1905, Ehrlich recognized it as a biological puzzle, but considered it inconceivable that animals could produce substances capable of specific recognition of toxins that the species had never encountere... |
2155403 | Codons 262 to 490 from the herpes simplex virus ICP4 gene are sufficient to encode a sequence-specific DNA binding protein. | The HSV-1 immediate early (IE) protein ICP4 (alpha 4, IE175, Vmw175) is an oligomeric molecule which activates transcription of viral early genes, represses transcription of viral IE genes, and binds to specific sequences in certain viral promoters. The extent to which these functions are interrelated has not been full... |
2407611 | Yeast mutants sensitive to antimicrotubule drugs define three genes that affect microtubule function. | Three new genes affecting microtubule function in Saccharomyces cerevisiae were isolated by screening for mutants displaying supersensitivity to the antimicrotubule drug benomyl. Such mutants fall into six complementation groups: TUB1, TUB2 and TUB3, the three tubulin genes of yeast, and three new genes, which we have ... |
2407610 | Mitotic chromosome transmission fidelity mutants in Saccharomyces cerevisiae. | We have isolated 136 independent mutations in haploid yeast strains that exhibit decreased chromosome transmission fidelity in mitosis. Eighty-five percent of the mutations are recessive and 15% are partially dominant. Complementation analysis between MATa and MAT alpha isolates identifies 11 chromosome transmission fi... |
2306549 | Characterization of photo-induced pyrimidine cyclobutane dimers by laser desorption Fourier transform mass spectrometry. | Laser desorption Fourier transform mass spectrometry was used to characterize the cis-syn cyclobutane photodimers of uracil-uracil, uracil-thymine and thymine-thymine. This soft ionization technique generated [M-H]- ions as well as some fragment ions. Investigation of the laser desorption process indicated that gas-pha... |
2304107 | Geriatric blunt multiple trauma: improved survival with early invasive monitoring. | Geriatric trauma survival rates are reported to approach 85%, but no series to our knowledge has included a predominance of multiply injured patients. In 1985, we treated 60 patients more than 65 years of age who sustained blunt multiple trauma, excluding burns and minor falls. A pedestrian-motor vehicle mechanism, ini... |
2105930 | Binding of tissue-type plasminogen activator with human endothelial cell monolayers. Characterization of the high affinity interaction with plasminogen activator inhibitor-1. | The formation and release of covalent complexes between tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) limits the application of equilibrium radioligand binding analysis to characterize the interaction between t-PA and human umbilical vein endothelial cell (HUVEC) monolayers. To ... |
1689238 | Mosaic structure of globular domains in the human type VI collagen alpha 3 chain: similarity to von Willebrand factor, fibronectin, actin, salivary proteins and aprotinin type protease inhibitors. | Human collagen alpha 3(VI) chain mRNA (approximately 10 kb) was cloned and shown by sequence analysis to encode a 25 residue signal peptide, a large N-terminal globule (1804 residues), a central triple helical segment (336 residues) and a C-terminal globule (803 residues). Some of the sequence was confirmed by Edman de... |
2303029 | The Rhizobium nodulation gene nodO encodes a Ca2(+)-binding protein that is exported without N-terminal cleavage and is homologous to haemolysin and related proteins. | Nodulation and host-specific recognition of legumes such as peas and Vicia spp. are encoded by the nodulation (nod) genes of Rhizobium leguminosarum biovar viciae. One of these genes, nodO, has been shown to encode an exported protein that contains a multiple tandem repeat of a nine amino acid domain. This domain was f... |
2302775 | Improved kinetic rate assay of urinary N-acetyl-beta-D-glucosaminidase with 2-chloro-4-nitrophenyl-N-acetyl-beta-D-glucosaminide as substrate. | We have improved the kinetic rate assay method for determining N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30; NAG) activity in urine with use of the synthetic substrate, 2-chloro-4-nitrophenyl-N-acetyl-beta-D-glucosaminide (CNP-NAG), reported previously (Clin Chem 1988;34:2140-2). To increase the solubility of this subs... |
2302306 | New fluorescence reactions in DNA cytochemistry. 1. Microscopic and spectroscopic studies on nonrigid fluorochromes. | Some nonrigid DNA-binding antibiotics and fluorochromes that recognize adenine-thymine (AT) sequences are widely applied in biomedical research, but the microscopic use, spectral characteristics and DNA binding modes of other similar compounds have been overlooked or scarcely explored. After treatment with thioflavine ... |
2301278 | Morphogenesis of endoplasmic reticulum in Xenopus oocytes after microinjection of rat liver smooth microsomes. | We have determined the kinetics of endoplasmic reticulum (ER) reconstitution following insertion of rat-liver smooth microsomes (SM) into Xenopus oocyte cytoplasm using electron microscopy as well as cytochemistry and thick-section 3-dimensional reconstruction. Oocytes were fixed 0, 10, 20, 40, 80, and 120 min after mi... |
2300576 | Transient analysis for antiproliferative gene activity. | A subset of tumor suppressor genes presumably functions by the inhibition of cellular proliferation; however, antiproliferative activity after transfection with putative suppressor genes has been difficult to demonstrate and often requires lengthy selection either in nude mice or in vitro. A rapid alternative is presen... |
2299643 | Lipophilic 1,3-xylyl-21-crown-6 macrocyclic polyether 2-carboxylic acids as biological mimics of the ionophore antibiotics. | Twelve lipophilic 1,3-xylyl-21-crown-6 macrocyclic polyether 2-carboxylic acids, two lariat ether 1,3-xylyl-21-crown-6 macrocyclic polyether 2-carboxylic acids, and two 1,3-xylyl-28-crown-8 macrocyclic polyether 2-carboxylic acids were synthesized and tested for in vitro antibacterial activity, in vitro stimulation of ... |
2299622 | Conformation-activity relationship of sweet molecules. Comparison of aspartame and naphthimidazolesulfonic acids. | The shape of the active site of the receptor for sweet molecules was previously defined on the basis of a combination of both rigid (saccharins) and flexible (aspartame) molds. In this paper, the sweetness receptor is refined with use of the shapes of 3-anilino-2-styryl-3H-naphtho[1,2-d]imidazolesulfonate (sweet) and o... |
2129537 | Structural characteristics of the variable regions of immunoglobulin genes encoding a pathogenic autoantibody in murine lupus. | We have studied several monoclonal anti-double-stranded (ds) DNA antibodies for their ability to accelerate lupus nephritis in young NZB X NZW F1 female mice and to induce it in BALB/c mice. Two identified as pathogens in both strains have characteristics previously associated with nephritogenicity: expression of IgG2a... |
2298811 | Parthenogenesis in Xenopus eggs requires centrosomal integrity. | Xenopus eggs are laid arrested at second metaphase of meiosis lacking a functional centrosome. Upon fertilization, the sperm provides the active centrosome that is required for cleavage to occur. The injection of purified centrosomes mimics fertilization and leads to tadpole formation (parthenogenesis). In this work we... |
2404957 | Effects of mutations in the repA gene of plasmid Rts1 on plasmid replication and autorepressor function. | We constructed a system in which wild-type RepA or RepAcop1 protein was supplied in trans in various amounts to coexisting mini-Rts1 plasmids by clones of the repA or repAcop1 gene under the control of the native promoter with or without its operator sequence. RepAcop1 protein which contains a single amino acid substit... |
2404867 | Cellular location of a Treponema denticola chymotrypsinlike protease and importance of the protease in migration through the basement membrane. | A number of immunological methods were used to localize a cell-associated Treponema denticola chymotrypsinlike protease. Indirect immunofluorescence staining, immunogold labeling, and an enzyme-linked immunosorbent assay all indicated that the protease was attached to the outside of the cell envelope. The invasive capa... |
2297725 | Stable bifunctional chelates of metals used in radiotherapy. | Monoclonal antibody technology allows the specificity of an antibody for its antigen to be used in targeting cancer cells. The conjugation of metals, particularly radionuclides such as 90Y or 67Cu, to monoclonal antibodies results in agents for radioimmunotherapy and other medical applications. Chelators that can hold ... |
2296086 | Molecular characterization of an attenuated human immunodeficiency virus type 2 isolate. | Naturally occurring strains of human immunodeficiency virus (HIV) can vary considerably in their in vitro biological properties, and such differences may also be reflected in their in vivo pathogenesis. In an attempt to define genetic determinants of viral pathogenicity, we have molecularly cloned, sequenced, and chara... |
2153224 | Three-dimensional structures of maturable and abortive capsids of equine herpesvirus 1 from cryoelectron microscopy. | Cryoelectron microscopy and three-dimensional computer reconstruction techniques have been used to compare the structures of two types of DNA-free capsids of equine herpesvirus 1 at a resolution of 4.5 nm. "Light" capsids are abortive, whereas "intermediate" capsids are related to maturable intracellular precursors. Th... |
2296075 | A Val-25-to-Ile substitution in the envelope precursor polyprotein, gPr80env, is responsible for the temperature sensitivity, inefficient processing of gPr80env, and neurovirulence of ts1, a mutant of Moloney murine leukemia virus TB. | ts1 is a neurovirulent spontaneous temperature-sensitive mutant of Moloney murine leukemia virus TB which causes hindlimb paralysis in mice. Previously, it had been shown that the temperature-sensitive defect resided in the env gene. At the restrictive temperature, the envelope precursor polyprotein, gPr80env, is ineff... |
17771883 | Quantum confinement and host/guest chemistry: probing a new dimension. | Nanoparticulate metals and semiconductors that have atomic arrangements at the interface of molecular clusters and "infinite" solid-state arrays of atoms have distinctive properties determined by the extent of confinement of highly delocalized valence electrons. At this interface, the total number of atoms and the geom... |
17771882 | Electrides: ionic salts with electrons as the anions. | Electrides are ionic compounds that have alkali metal cations complexed by a crown ether or cryptand, with trapped electrons as counterions. The crystal structures and properties of two electrides illustrate the diversity that is encountered. One Cs(+) (18-crown-6)(z)e(-), has relatively isolated, trapped electrons app... |
16348121 | CO(2) Incorporation and 4-Hydroxy-2-Methylbenzoic Acid Formation during Anaerobic Metabolism of m-Cresol by a Methanogenic Consortium. | The metabolism of m-cresol by methanogenic cultures enriched from domestic sewage sludge was investigated. In the initial studies, bromoethanesulfonic acid was used to inhibit methane production. This led to the accumulation of 4.0 +/- 0.8 mol of acetate per mol of m-cresol metabolized. These results suggested that CO(... |
1966965 | Paramagnetic agents as tracers in magnetic resonance imaging. Extrapolations from Gd-DTPA to everything. | The range of compounds, both paramagnetic and ferromagnetic, with potential utility as tracers for enhancing contrast in magnetic resonance imaging is very large. Fortunately, the changes in 1/T1 and 1/T2 of water protons in solution--and ultimately in tissue--induced by these agents arise from variations of only a few... |
2103347 | Structural diversity and dynamics of microtubules and polymorphic tubulin assemblies. | Tubulin, the main protein of microtubules (MTs), has the potency of forming a variety of other assembly products in vitro: rings, ring-crystals, C- and S-shaped ribbons, 10 nm fibres, hoops, sheets, heaped sheets, MT doublets, MT triplets, double-wall MTs, microtubules, curled ribbons, and paracrystals. The supramolecu... |
2151670 | DNA strand scission by neocarzinostatin: molecular recognition process responsible for site-specificity. | A series of hexanucleotides possessing A-T, G-C, inosine (I)-C and 2-aminoadenine (ANH2)-T base pairs at 5'-side of the target thymine were prepared and their selectivity for C-5' and C4' oxidation in the NCS-mediated degradation was investigated. Quantitative product analysis indicated that preferential C5' oxidation ... |
2100631 | On-line recovery of trimeprazine enantiomers following chiral separation by reversed-phase high-performance liquid chromatography using a beta-cyclodextrin-containing mobile phase. | A procedure is described which allows the on-line recovery of enantiomers following semi-preparative chiral separation by RP-HPLC using beta-cyclodextrin in the mobile phase. By this method, the phenothiazine antihistamine trimeprazine (I) was resolved into its antipodes at greater than 95% optical purity at a throughp... |
2100609 | Comparison of a calixarene-based ion-selective electrode with two automated analyzers for the clinical determination of sodium in blood plasma. | Neutral-carrier ion-selective electrodes based on methyl p-t-butylcalix[4]aryl acetate have been prepared that are responsive to sodium ions. The miniaturized catheter-type electrodes were obtained by dip-coating their porcelain tips in a PVC membrane cocktail. Examination of the general performance of the electrodes r... |
2100606 | Equilibrium kinetics of the new experimental anti-tumour compound SK&F 104864-A in aqueous solution. | The equilibrium kinetics of lactone ring hydrolysis in the new experimental anti-tumour compound SK&F 104864-A. (S)-dimethylaminomethyl-10-hydroxycamptothecin hydrochloride, have been studied. Only one product is formed, SK&F 105992. A stability-indicating HPLC method has been optimized to perform the analysis. The pH ... |
2100605 | Inclusion complexation of doxorubicin and daunorubicin with cyclodextrins. | The interaction of alpha-, beta- and gamma-cyclodextrins with the anthracycline antibiotics doxorubicin and daunorubicin was investigated by LC, circular dichroism (CD) and absorption spectroscopy. All studies were performed in aqueous media at different temperatures and pH values. The anthracyclines complex only with ... |
2100199 | Effects of phosphorylation of the neurofilament L protein on filamentous structures. | Effects of phosphorylation of the neurofilament L protein (NF-L) on the reassembly system were studied by both sedimentation experiments and low-angle rotary shadowing. Bovine spinal cord NF-L was phosphorylated with 3-4 mol/mol protein by either the catalytic subunit of cAMP-dependent protein kinase or protein kinase ... |
2100172 | Beta-cyclodextrins as vehicles in eye-drop formulations: an evaluation of their effects on rabbit corneal epithelium. | Beta-cyclodextrins are cyclic molecules with a hydrophilic outer side and a central hydrophobic cavity. Through the inclusion of drug molecules into their cavities, i.e. the formation of inclusion complexes, cyclodextrins are able to modify the physical and chemical properties of these molecules. When used in pharmaceu... |
2094413 | Cyclodextrin chiral stationary phases for liquid chromatographic separations of drug stereoisomers. | Many active drugs are racemic mixtures. Because the two enantiomers of a racemate often cause different pharmacological responses, the use of optically pure isomers is desirable and may be soon required. Cyclodextrin-bonded silica gel can be used as chiral stationary phase (CSP) in liquid chromatography. The enantiomer... |
2094128 | Differentiation control in cell cycle and development based on the alterations of higher-order chromatin structure. Theory and applications to radiation and chemical action. | A theoretical model of genes switching during development and cell cycle is proposed. The model is based on the assumption concerning the connection between differentiation state and distribution of chromatin domains in the nucleus. Radiation and chemicals action as supposed in the model is realized not at the DNA seco... |
2093245 | [An analysis of the supramolecular organization of the olfactory neuroepithelium in the rat by freeze etching with rotary platinum-carbon shadow-casting]. | The rat olfactory epithelium was analysed by freeze-deep etching and Pt/C rotary replication. Ultrathin sections and freeze-etching findings of proximal (dendrite) and distal (axon) parts of bipolar olfactory neurons are examined. The supramolecular organization of neuron membranes and intracellular cytoskeleton struct... |
2093242 | [The supramolecular organization of the keratinocyte cytoskeleton and extracellular matrix in human skin revealed by freezing-deep etching with rotary platinum-carbon shadow-casting]. | The supramolecular organization of the keratinocyte cytoskeleton, the basal lamina and of the dermal extracellular matrix in the whole human skin revealed by freeze-deep etching with Pt/C rotary shadowing is presented. The routine equipment for this method and sample preparation are described. The resolution of the met... |
2150991 | Anticonvulsant effects of clonazepam on chemically induced convulsions. | The anticonvulsant effects of two doses of clonazepam (CZP, Rivotril Roche, 0.1 and 1 mg/kg i.p.) were studied on model motor seizures induced by strychnine, bicuculline, 3-mercaptopropionic acid and metrazol in male laboratory rats (Wistar strain). In the first part the effects of different doses of the convulsants we... |
2289989 | Mediators of multiple organ failure. | Multiple Organ Failure (MOF) has largely been attributed to bacterial sepsis, though conclusive evidence of an essential role for bacteria and/or their endotoxins is still lacking. On the other hand, MOF and the clinical syndrome of sepsis may be aseptically induced in germ-free animals. This paper reviews the evidence... |
2289983 | Hemodynamic aspects of multiple organ failure. | Multiple organ failure (MOF) secondary to sepsis is associated with a high mortality. A large body of evidence suggests that the disturbed relationship between oxygen supply and oxygen uptake plays an important role in the pathogenesis of MOF. The relationship between oxygen-supply dependency and MOF and the practical ... |
2288149 | [The effect of central electroanalgesia on the structural changes in the nerve fibers of patients with atopic dermatitis]. | Nerve fibers ultrastructure in dermal papillary layer from foci of involvement was examined in atopic dermatitis patients before and after therapy with central electroanalgesia. Before therapy considerable destructive changes in nerve fibers were seen, i. e. Schwann cell cytoplasm and nerve cell appendages edemas, no n... |
2284978 | [A study of the inclusion complex of WB852 with beta-cyclodextrin]. | The aim of this study was to increase the stability of WB852 in aqueous solution by inclusion complex formation with beta-cyclodextrin (beta-CD). The stability of WB852-beta-CD in aqueous solution was determined. The hydrolysis rate of WB852 from the inclusion compound was lower than that of WB852 alone. The solid incl... |
2284953 | [Studies on the composition and stability constant of inclusion complexes of beta-cyclodextrin with fluorouracil and ftorafur by NMR]. | The composition and stability constants of the host-guest inclusion complexes of beta-cyclodextrin (beta-CD) with fluorouracil (5-Fu) and ftorafur (FT-207) were studied by 19F NMR. The 19F chemical shift changes (delta) of 5-Fu and FT-207 on complexation with beta-CD were used to determine the stoichiometry of these in... |
2283837 | Postoperative subphrenic abscess following gastrectomy for gastric cancer. | From 1985 to 1989, a total of 598 gastric cancer patients underwent gastrectomies in the First Department of Surgery at Kurume University School of Medicine. Of these, 24 patients (4.0%) incurred a subphrenic abscess, postoperatively. Subphrenic abscesses occurred most frequently after total gastrectomies at a rate of ... |
2268508 | Receptors, inositol polyphosphates and intracellular Ca2+. | 1. A large number of cell-surface receptors catalyse the activation of phospholipase C via a guanine nucleotide exchange protein and generate at least two important intracellular second messengers. One of these, inositol(1,4,5) trisphosphate, binds to specific intracellular receptors and releases Ca2+ from intracellula... |
2148361 | Behavior and physiological effects of supplemental episodes of testosterone, its precursors and metabolite in rats. | Androgen-sensitive behavior and physiology were examined in gonadally intact male rats receiving daily injections of steroids (0.4 mg/kg) in two pharmaceutical forms for one month. When steroids were injected as aqueous solutions of hydroxypropyl-beta-cyclodextrin complexes, a form which insures a rapid distribution th... |
2262053 | Molecules of the extracellular matrix: potential role of collagens and glycoproteins in intestinal adaptation. | The extracellular matrix plays a fundamental role in modulating cellular growth, differentiation and migration. Therefore it merits major attention in studies of adaptation. The five types of collagen and several extracellular glycoproteins hitherto found in the intestine are biochemically well defined. They form supra... |
2261511 | New pharmacological studies with pentoxifylline. | Polymorphonuclear (PMN) overactivation plays a critical role in microcirculation as well as in conditions such as multiorgan failure (MOF). Pentoxifylline has been shown to prevent PMN activation by endotoxin and cytokines such as TNF alpha and IL-1. In addition, MOF induced by IL-2 in animals can be prevented by pento... |
2253664 | Pharmacokinetics and pharmacodynamics of cicaprost in healthy volunteers after oral administration of 5 to 20 micrograms. | In a Phase I study, the tolerability, pharmacodynamics and pharmacokinetics of cicaprost have been investigated in 6 male volunteers given 5, 10, 15 and 20 micrograms as tablets of the beta-cyclodextrin clathrate. Individual inhibition of platelet aggregation and changes in facial colour (measured by chromametry) were ... |
2252846 | Direct resolution of some phenylglycines by liquid chromatography on a chiral crown ether phase. | The optical resolution of a series of 12 amino acids of the phenylglycine family was studied using a chiral crown ether column. The effects of pH, temperature, and mobile phase additive were investigated. In three examples it was confirmed that the R enantiomer eluted prior to the S enantiomer. Most phenylglycines were... |
2236182 | Effect of beta-cyclodextrin on the in vitro permeation rate and in vivo rectal absorption of acetaminophen hydrogel preparations. | The amounts of beta-cyclodextrin and hydroxyl propyl methyl cellulose (HPMC) affecting the in vitro permeation rate of acetaminophen containing in both aqueous solutions and HPMC hydrogel preparations through the dialyzer tubing and isolated rat rectum were investigated. The partition coefficient of acetaminophen with ... |
2229140 | Down-regulation of androgen receptor by progestins and interference with estrogenic or androgenic stimulation of mammary carcinoma cell growth. | The regulatory influence of medroxyprogesterone acetate (MPA) on estrogen and androgen receptors of the human breast cancer cell lines MCF-7 and EFM-19 was explored in conjunction with the growth-promoting properties of these steroids. In the absence of steroidal stimulation, up to 1 microM MPA had no effect on the pro... |
1699307 | A solution for removal of resin from epoxy sections. | Development of a resin-dissolving solution for use at low alkali concentrations is described. Crown ether dissolved in dimethyl-sulfoxide produces a superbasic alkoxide anion. A five minute treatment resulted in complete resin removal from kidney biopsy specimens embedded in Epon 812. Specimens were well stained by Loe... |
1366583 | A new cyclodextrin-agar medium for surface cultivation of microbes on lipophilic substrates. | Inclusion of cyclodextrins into an agar gel enabled a homogeneous incorporation of water-immiscible lipophilic organic liquids and solids as substrates for surface microbial growth or conversion. Surface cultivation of Candida lipolytica and C. tropicalis was demonstrated in alpha- and beta-cyclodextrin/hexadecane-agar... |
1976291 | Structural characteristics of compounds that modulate P-glycoprotein-associated multidrug resistance. | Multidrug resistance is mediated by a membrane-bound protein, P-gp, that functions as an energy dependent efflux system to reduce the intracellular concentration of anticancer drugs by binding to these drugs and actively exporting them from the cell. Compounds that interact with P-gp and compete with anticancer drug bi... |
2168810 | Microenvironment of the peripheral nervous system under normal and pathological conditions. | The peripheral nervous system (PNS) is composed of neurons and their processes which are located in a special fluid microenvironment. As is well known, complex biological functions such as those going on in peripheral nerves are best carried out when there is homeostasis, i.e., in a constant internal milieu. This paper... |
2100999 | Preparation, 252Cf-plasma-desorption mass spectrometry and radiometal exchange of the Pb2+ and Bi3+ complexes of a hexalactam macrocycle. | A macrocyclic tricatechol hexalactam ligand readily forms complexes with Pb2+ and Bi3+ ions. Solid samples were isolated and characterized by 252Cf-plasma-desorption mass spectroscopy (252Cf-PDMS). Radioactive metal exchange studies employing 210Pb and 210Bi showed the compounds to be kinetically inert to exchange. The... |
1368525 | Practical debittering using model peptides and related compounds. | In order to develop a practical debittering method for amino acids and peptides, several debittering methods were studied. The authors found that hooking acidic amino acids to and acetylation of bitter amino acids is very effective to remove the bitterness from their concentrated solution. For debittering by mixing wit... |
1368519 | Comparison of CD composition produced by chimeric CGTases. | Using 12 chimeric cyclomaltodextrin glucanotransferases (CGTases) constructed from two genes, the CGTase gene from the alkalophilic Bacillus sp. strain No. 38-2 (CGTase 38-2 gene) and the CGTase gene from the alkalophilic Bacillus sp. strain No. 17-1 (CGTase 17-1 gene), we compared the effect of those chimeric enzymes ... |
1367429 | Cyclodextrin-facilitated bioconversion of 17 beta-estradiol by a phenoloxidase from Mucuna pruriens cell cultures. | After complexation with beta-cyclodextrin, the phenolic steroid 17 beta-estradiol could be ortho-hydroxylated into a catechol, mainly 4-hydroxyestradiol, by a phenoloxidase from in vitro grown cells of Mucuna pruriens. By complexation with beta-cyclodextrin the solubility of the steroid increased from almost insoluble ... |
2165978 | Group-recognition ability of derivatized beta-cyclodextrin as studied by the ESR spin probing technique. | The effect of modifying the entrance face of beta-cyclodextrin on the inclusion of various functional groups in aminoxyl spin probes was determined by the use of heptakis (2,6-O-dimethyl)-beta-cyclodextrin and heptakis (2,3,6-O-triacetyl)-beta-cyclodextrin. The methylation of six of the secondary hydroxyl groups on the... |
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