Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The administration of multiple doses of cocaine on a single day during late gestation is teratogenic in rats in which hind limb ectrodactyly is a major finding (Webster and Brown-Woodman, '90). We have previously hypothesized that these limb malformations result from the generation of reactive oxygen species during the process of ischemia/reperfusion in vivo. In order to study the direct effects of cocaine versus the aberrant oxygenation it may induce, we have developed a system for culturing rat embryos between days 14 and 15 of gestation. Growth and development of cultured embryos are comparable to that of in vivo controls. Exposure to normoxia (95% O2) with or without cocaine failed to induce limb malformations and exposure to a single long period of hypoxia (20% O2) only reduced limb growth in the anterior-posterior axis. By contrast, embryos receiving multiple brief exposures to hypoxia developed a significant incidence of hind limb ectrodactyly that appeared indistinguishable from that induced by cocaine in vivo. By incubating day 14 embryos in a nitroblue tetrazolium derivative, 1-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), it was shown that superoxide anion radical appears in the digital rays following two episodes of reperfusion. Little reaction product was seen under the other conditions. Finally, mitochondrial electron transport particles prepared from teratogenically sensitive limb buds spontaneously "leak" electrons to form superoxide anion radical whereas those from insensitive heart fail to do so. We propose that cocaine and other exposures that can transiently reduce conceptual oxygenation during late gestation are teratogenic by virtue of their capacity to induce ischemia/reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies of the role of ischemia/reperfusion and superoxide anion radical production in the teratogenicity of cocaine. 132 33

T lymphocyte lines specific for the peripheral nerve myelin protein P2 were selected from the lymph nodes of Brown Norway (BN) rats immunized with bovine P2 protein in complete Freund's adjuvant. These T cells expressed the W3/25+, OX8-phenotype and responded specifically to bovine P2 protein, but not to PPD or bovine basic protein, in T cell proliferation assays. When injected i.v. into syngeneic recipients, BN P2-specific T cell lines induced both clinical and histologic signs of experimental allergic neuritis (EAN), overcoming the resistance of this rat strain to actively induced EAN. Although the histopathology of the disease was indistinguishable from that seen in T cell-mediated EAN in the Lewis rat, disease onset was considerably later, 7 to 8 days after cell transfer, as opposed to 4 days in Lewis. This lag phase between inoculation and disease onset could not be further reduced even by raising the cell dose to 50 X 10(6) cells/host. The fine specificity of the T cell response to P2 differs between Lewis- and BN-derived T cell lines. At least one neuritogenic epitope for each strain was present in the cyanogen bromide-derived peptide CB2 (residues 21-113), as shown by the ability of CB2-specific T cell lines derived from each strain to transfer EAN to the appropriate host strain. However, neuritogenic BN T lines fail to mount a response to the sequence 53-78 (SP4), which encompasses an epitope that is neuritogenic for Lewis rats. These results demonstrate that the resistance of BN rats to actively induced EAN is not due to the lack of appropriate P2-specific autoreactive T cell clones in the normal T repertoire. Furthermore, the results suggest that two distinct epitopes of P2 are responsible for EAN in Lewis and BN rats.
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PMID:Induction of experimental allergic neuritis in the BN rat: P2 protein-specific T cells overcome resistance to actively induced disease. 243 Oct 45

Brown oxidation of cis-bicyclo[3.1.0]hexan-3-ol afforded bicyclo[3.1.0]hexan-3-one in 98% yield. Treatment of this ketone with either phenyllithium or phenylamagnesium bromide in ether at room temperature followed by solvolysis of the resulting alcohol in a mixture of trifluoroacetic acid, sodium azide, and chloroform gave a mixture of cis- and trans-3-azido-3-phenylbicyclo[3.1.0]hexanes. LAH reduction of this crude mixture of azides afforded a 1:3.5 mixture of cis- and trans-3-phenyl-3-bicyclo[3.1.0]hexylamine, respectively, in 51% overall yield from the alcohol. Separation of the mixture of amines by column chromatography followed by cyclization of each by heating at 60 degrees C in DMF solution with 1 equiv of 1,5-dibromopentane furnished the two conformationally restrained analogues of phencyclidine (PCP), cis- and trans-3-phenyl-3-piperidinylbicyclo[3.1.0]hexane (1 and 2, respectively), in high yield. Configurations were assigned on the basis of an X-ray crystallographic analysis of the cis isomer (1). Bond lengths and angles are similar to those found in PCP and its derivatives. Binding to PCP receptors and sigma sites as well as behavioral effects of 1 and 2 in rats was determined relative to PCP. In displacement of specifically bound [3H]TCP (1-[1-(2-thienyl)cyclohexyl]piperidine) from PCP receptors, 1 and 2 were nearly equipotent and about one-seventh as potent as PCP. These compounds were about one-fifth as potent as PCP in displacing [3H]-(+)-SKF 10,047 from its binding site. Calculation of the ED50 values of 1 and 2 for stereotyped behavior and ataxia indicated that they were about equipotent, and 2-3-fold less active than PCP.
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PMID:Synthesis, configuration, and evaluation of two conformationally restrained analogues of phencyclidine. 339 94

Catechin dimers induce a large long-lasting oedema when injected in the paw of the rat. This oedema is not inhibited by methysergide, promethazine, indomethacin, phenidone, bromophenacyl bromide and colchicine. It is not modified in rats made leukopenic by methotrexate. It is slightly delayed in Brown Norway rats which were kallikrein-kininogen deficient. Similarly catechin dimers induce the formation of a large peritoneal exudate in the rat. The exudate contains insignificant levels of leucocytes and 5-hydroxytryptamine. It contains kinins but its PG content is very low. The exudate does not activate (14C)-arachidonic acid into PG. Catechin dimers induce kinin formation in rat plasma "in vitro". They inhibit the formation of PG and HETE-like compounds from (14C)-arachidonic acid by rat peritoneal cells "in vitro". Catechin dimers administered at sub-irritant doses reduced carrageenan-induced oedema. Catechin dimers at low doses have an anti-inflammatory effect which may depend on PG synthesis inhibition. At larger doses, they induce inflammatory responses which occur with almost complete lack of participation of PG.
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PMID:Pro-inflammatory flavonoids which are inhibitors of prostaglandin biosynthesis. 392 75

We studied the hypotensive effect of three carrageenans and of dextran sulphate in Brown Norway (BN) rats. The plasma of these BN rats is devoid of high molecular weight kininogen and poor in plasma prekallikrein. The hypotensive effect in BN rats was greatly reduced in comparison with the effects in normal rats. It was proportional to the thrombocytopenia induced by the sulphated polysaccharides and absent in rats made thrombopenic by antiplatelet serum. The hypotensive effect in BN rats was reduced by bromophenacyl bromide, mepacrine, aspirin, methysergide, promethazine and CCI 17810, and was unchanged after the administration of cobra venom factor, heparin, amino caproic acid, chloroquine, dexamethazone, lidocaine, propranolol, indomethacin, phenidone, imidazol, adenosine and cyproheptadine. The thrombopenic effect was reduced by methysergide and CCI 17810 and was not modified by bromophenacyl bromide and chloroquine.
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PMID:[Platelet stimulation and hypotensive action of carrageenans in the rat]. 667 65

The complete amino acid sequences of the alpha and beta subunits of allophycocyanin from the unicellular rhodophyte, Cyanidium caldarium, were determined by automated Edman degradation of the proteins and peptides derived from them by chemical and enzymatic cleavages. The sequence of the alpha subunit was determined from the sequences of tryptic, endoproteinase lysine-C, and cyanogen bromide peptides and carboxypeptidase A and Y digestion of the protein. The sequence of the beta subunit was determined from the sequences of tryptic, endoproteinase lysine-C, Staphylococcus aureus V8 protease, and cyanogen bromide peptides and in addition, a peptide derived from acid cleavage of an aspartyl-prolyl bond. The carboxyl-terminal sequence of the protein was determined by digestion with carboxypeptidase A. The alpha subunit contains 160 amino acids, one phycocyanobilin chromophore attached at residue 80 by a cysteinyl-thioether linkage, and the Mr calculated from the sequence is 18,160. The beta subunit contains 161 amino acids, one phycocyanobilin chromophore attached at residue 81 by a cysteinyl-thioether linkage, and the Mr calculated from the sequence is 18,125. The amino acid sequences of the alpha and beta subunits of allophycocyanin from C. caldarium are the first complete amino acid sequences of an allophycocyanin from a eukaryotic red alga. A matrix comparison of the alpha and beta subunits of C. caldarium allophycocyanin and phycocyanin (Offner, G.D., Brown-Mason, A.S., Ehrhardt, M. M., and Troxler, R. F. (1981) J. Biol. Chem. 256, 12167-12175; Troxler, R. F., Ehrhardt, M. M., Brown-Mason, A. S., and Offner, G. D. (1981) J. Biol. Chem. 256, 12176-12184) shows homology ranging from 26 to 39%. Comparison of the sequences of alpha and beta subunits of C. caldarium allophycocyanin with the sequences of the corresponding subunits of allophycocyanin from two prokaryotic cyanobacteria (Sidler, W., Gysi, J., Isker, E., and Zuber, H. (1981) Hoppe-Seyler's Z. Physiol. Chem. 362, 611-628; DeLange, R. J., Williams, L. C. and Glazer, A. N. (1981) J. Biol. Chem. 256, 9558-9566) shows homology ranging from 81 to 85%. The significance of this with respect to phycobiliprotein structure and function is discussed.
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PMID:Primary structure of allophycocyanin from the unicellular rhodophyte, Cyanidium caldarium. The complete amino acid sequences of the alpha and beta subunits. 688 76

Bladder instability provokes frequency, urgency, urge incontinence and enuresis in a great percentage of patients of both sexes, who undergo urodynamic examination when other clinical elements are not in evidence. The presence of bladder contractions of variable entity, even capable of inducing emptying, during filling are accompanied by a strong desire to micturate. Our study includes daily recordings of rhythm and quantity of micturitions and leaks, evaluation of urethral pressure, transurethral cystometry and uroflowmetry. The urethral pressure profile was performed with the technique of Brown and Wickham by infusing at 2 ml/min with 10-Ch catheter, withdrawn at a speed of 15 cm/min. Transurethral cystometry was performed by a continuous infusion at moderate speed (50 ml/min) of an isotonic solution at room temperature in a recumbent patient with two catheters in the bladder. When the contractions of the detrusor appear, we evaluate the pharmacological response to the filling with a myolitic agent (flavoxate) first, and with synthetic anticholinergic (emepronium bromide) after, with the purpose of discriminating the myogenic or neurogenic nature of the alteration and to propose suitable therapy.
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PMID:Urodynamic response of unstable bladder to flavoxate. 738 65

N-Glycoloylneuraminic acid (Neu5Gc) is synthesized as its CMP-glycoside by the action of CMP-N-acetylneuraminic acid (CMP-Neu5Ac) hydroxylase. This enzyme is a soluble cytochrome b5-dependent monooxygenase and has been purified to apparent homogeneity from pig submandibular glands by precipitation with N-cetyl-N,N,N-trimethylammonium bromide and fractionation on Q-Sepharose, Cibacron Blue 3GA-Agarose, Reactive Brown 10-Agarose, Hexyl-Agarose and Superose S.12. This procedure resulted in an 8960-fold purification of the hydroxylase with a recovery of 0.8%. The molecular mass of this protein was shown to be 65 kDa on SDS-PAGE and approximately 60 kDa as determined by gel filtration on Superose S.12, which suggests that the enzyme is a monomer. The purified CMP-Neu5Ac hydroxylase is activated by FeSO4 and inhibited by iron-binding reagents such as o-phenanthroline, KCN, Tiron and ferrozine. An apparent Km of 11 microM was determined for the substrate CMP-Neu5Ac using purified hydroxylase in the presence of Triton X-100-solubilized microsomes. In a reconstituted system consisting of purified hydroxylase, cytochrome b5, cytochrome b5 reductase and catalase, an apparent Km of 3 microM was measured. The apparent Km for cytochrome b5 in this system was 0.24 microM. Immunization of a rabbit with enriched and purified hydroxylase led to an antiserum that inhibited CMP-Neu5Ac hydroxylase activity and reacted with the purified 65 kDa protein on a Western blot after SDS-PAGE. Antibodies specific for this 65 kDa protein were isolated and showed a strong reaction with the purified CMP-Neu5Ac hydroxylase from mouse liver after immunoblotting.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Purification and characterization of CMP-N-acetylneuraminic acid hydroxylase from pig submandibular glands. 788 Nov 82

Previous work has identified a prominent 22-24-kD protein that is present in rat male reproductive tissues, including epididymis and testis (Brooks, 1985; Jones and Brown, 1987; Moore et al., 1987). Using a monoclonal antibody (designated mAb-B109) against this 24-kD antigen (referred to as B109), we have isolated the protein using a combination of chromatofocusing and electroelution from SDS-PAGE gels, and reverse phase HPLC. B109 (pI = 4.8) is amino-terminal blocked. To obtain internal amino acid sequences, the isolated protein was cleaved either with cyanogen bromide in 70% formic acid or with TLCK-treated chymotrypsin. With cyanogen bromide treatment, two peptides, 17.8 kD and 11.9 kD, were isolated and partial amino acid sequences obtained. Chymotryptic peptides were isolated by reverse-phase HPLC and two were chosen for sequence analysis. A computer search for sequence homology through the protein identification resource (PIR) matched B109 to a basic 21-kD cytosolic protein (pI = 7.4) found in bovine brain (> 80% homology). When peptide sequence differences obtained in the present study were substituted into the 21-kD cytosolic protein sequence obtained from the PIR using Intelligenetics software, the calculated pI dropped from 7.4 to 5.8, suggesting that pI differences between the bovine and rat molecules are the result of amino acid substitutions in the testis protein and not tissue-specific posttranslational processing. It has been postulated that the 21-kD bovine brain protein is associated with phospholipid transport, although the function of B109 is unknown.
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PMID:Putative rat sperm lipid-binding protein: isolation and partial characterization. 788 68

Brown adipose tissue (BAT) is thought to be responsible for increased heat production in cold-acclimated rodents. We measured sympathetic nerve activity (SNA) in interscapular BAT (IBAT) during cold stimulation in cold-acclimated C57BL/6J mice (ACCLI). Cold acclimation was achieved (cold tolerance was increased) by repeated exposure to cold stress every other week for 3 weeks. We compared SNA in these animals with SNA in mice that had no previous cold stress experience (naive). During the test, mice were anesthetized by urethane and isoflurane and were paralyzed with vecuronium bromide. Sympathetic nerve activity was recorded directly from one of the fine nerves to IBAT. The animal's body caudal to the pelvic area was covered with a plastic bag containing a slurry of ice water to decrease colonic temperature 7 degrees C below control level, which took approximately 20 min. Interscapular BAT-SNA increased during cold stress in both groups, but ACCLI mice had higher IBAT-SNA during cold stress than naive mice. These findings confirmed the hypothesis that during the acute cold exposure, cold-acclimated mice have greater sympathetic outflow to BAT adipocytes.
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PMID:Sympathetic nervous activity to brown adipose tissue increases in cold-tolerant mice. 802 14


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