Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antigenic determinants of LH-releasing hormone (LH-RH) were investigated by testing the cross-reaction of LH-RH analogues and fragments in LH-RH radioimmunoassay (RIA) systems using 3 different antisera against the LH-RH decapeptide. Rabbit antiserum No. 419 was generated against LH-RH adsorbed on polyvinylpyrrolidone (PVP). Antisera Nos. 710 and 742 were produced by immunizing rabbits with LH-RH conjugated either with bovine serum albumin through its C-terminus, or with human serum albumin through the N-terminus, respectively. For antiserum No. 419, the N-terminal (pyro)-glutamic acid and/or histidine in positions 1 and 2 of LH-RH, respectively, were found to enhance the antigen-antibody interaction, but were not indispensable for it. Similarly, the C-terminal amide and glycine-NH2 did not play a major role in these interactions. The LH-RH heptapeptide fragment, corresponding to amino acid sequence from positions 3 to 9, showed a cross-reactivity in this RIA system with LH-RH, although greater amounts than those of cold LH-RH were required for a comparable inhibition of binding of labelled LH-RH. For antiserum No. 710, the LH-RH hexapeptide fragment corresponding to positions 2 to 7 showed considerable cross-reactivity. Histidine in position 2 played an important role but neither the amide group nor the glycine amide group at the C-terminus were essential. For antiserum No. 742, the C-terminal tetrapeptide-amide fragment of LH-RH showed considerable cross-reactivity in the LH-RH, the amide moiety itself being of crucial importance. These antisera may be useful in investigating peptides related to LH-RH in biological materials.
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PMID:The antigenic determinant of the LH-releasing hormone for three different antisera. 4 82

Carbohydrates roughly constitute 15 p. 100 of the dry matter of Sirulina. They are extracted after complete delipidation, by successive exhaustions: first with ethanol of decreasing title, then with cold water slightly acidified by chlorhydric acid in order to drain out the calcium of the phytate; then by neutral boiling water; at last by alkaline or acidic warm solutions. After neutralization, suitable defecation and concentration, carbohydrates are either purified by a slow cristalization or hydrolyzed and analysed by usual techniques of chromatography on paper or on column of borated resins. Glucose, levulose, sucrose, glycerol and several polyols are so detected. They are in small amounts and of little nutritional interest. There is no trehalose. The carbohydrate storage products are mainly a glucosan and a rhamnosan, both containing glucosamine. There is about 2 p. 100 of the glucosan and 10 p. 100 of the rhamnosan, the composition of which are, in molar ratio: (see text). More or less phosphated cyclitols constitute, together with a small amount of glycogen, the rest of the metabolisable part. The cell-walls which could not be perfectly purified were degraded either by HC1 or by enzymes (pronase, neuraminidase). So have been found glucosamine and muramic acid, associated with peptides rich in glycine, serine, alanine, glutamic acid. These results joined to the presence, formerly signaled, of a rhamnosan, reveal a relationship between Spirulina and some Gram(+) bacteria. It is a fact that the celle-walls of Spirulina actually, though weakly, take the Gram coloration. To conclude, Spirulina presents some alimental interest.
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PMID:[Carbohydrates synthesized by the spirulines]. 82 97

The phenomenon of redistribution of surface membrane immunoglobulin (Ig) components (capping) has been well described in mouse lymphoid cells. The characteristics of this process in human lymphocytes are less clear. This study characterizes the phenomenon of surface membrane Ig redistribution of normal and chronic lymphocytic leukemia (CLL) lymphocytes with the use of fluoroscein-labeled anti-Ig sera. Normal lymphocytes underwent rapid cap formation after incubation with anti-Ig serum in the cold and subsequent rewarming. The morphology was characteristic with aggregation over the pole of the cell opposite the nucleus and over the uropod when present. The process was energy dependent but independent of protein synthesis, and could be inhibited by vincristine, vinblastine, and colchicine but not by cytochalasin B. CLL cells, on the other hand, though showing fluorescent complex aggregation on the surface, rarely demonstrated unidirectional movement of these aggregates to form a cap. Cap formation in these cells could not be stimulated by supplementing the energy source or protein concentration of the medium nor by adding glutamic acid which could partially reverse the vincristine and vinblastine inhibition of normal capping. The failure of agents which inhibit motility to inhibit capping of the normal lymphocytes suggests that active locomotion is not a direct prerequisite for capping. The results also suggest the involvement of microtubules in normal capping and the possibility that abnormal membrane structure or microtubular function could explain the failure of CLL cells to behave normally in this regard. The role of this cellular defect in the immune deficiencies exhibited by many patients with CLL, however, is not established.
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PMID:Human lymphocyte surface immunoglobulin capping. Normal characteristics and anomalous behavior of chronic lymphocytic leukemic lymphocytes. 108 10

To identify and characterize endothelial cell surface components that bind plasminogen, we used ligand-blotting to study binding of plasminogen to sodium dodecyl sulphate solubilized extracts of human umbilical vein endothelial cells. It was observed that glu-plasminogen bound predominantly to a 45 kDa endothelial cell polypeptide. The interaction of labelled glu-plasminogen with this polypeptide was reversible and specific as the binding could be inhibited by both excess cold lysine and unlabelled glu-plasminogen but not by unrelated proteins. Binding of glu-plasminogen to cell extracts prepared from endothelial cells that had been pretreated with proteinase K was significantly reduced indicating that the 45 kDa polypeptide is a cell-surface protein. The cell-surface localization of the 45 kDa polypeptide was also indicated by the positive interaction of glu-plasminogen with membrane fractions of endothelial cells. Lys-plasminogen also interacted with the 45 kDa polypeptide in a specific manner and reversibility experiments indicated that lys-plasminogen could also displace the bound glu-plasminogen. Since binding of plasminogen to the 45 kDa endothelial cell surface polypeptide was very similar to plasminogen binding to intact endothelial cells, we propose that the 45 kDa protein represents one of the major receptors for plasminogen on human endothelial cells.
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PMID:Identification of an endothelial cell surface protein that binds plasminogen. 166 40

The two stereoisomers of pyroglutamic acid (PCA), a nootropic or cognition-enhancing agent, and classic reference compounds were investigated for their ability to interact with 27 neurotransmitter receptors and drug binding sites prepared from selected areas of the central nervous system and labelled with high affinity and selectivity with specific radioligands. L-PCA significantly interacted with the rat forebrain excitatory amino acid receptors labelled with 3H-L-glutamic acid. The IC50 of L-PCA was 28.11 microM, that of cold L-glutamic acid was 1.68 microM. The corresponding figure for L-aspartic acid was 16.95 microM. The indirect Hill plot gave coefficients of 0.48, 1.08 and 0.75 for L-PCA, L-glutamic and L-aspartic acids, respectively. Only very high concentrations (10(-4) M) of L-PCA were able to slightly antagonize the specific binding of 3H-clonidine to alpha 2-adrenergic receptors, of 3H-dihydroalprenolol to beta 1- and beta 2-adrenergic receptors of the heart and of the lung and of 3H-diazepam to benzodiazepine receptors. The D-isomer of PCA was practically as active as the L-isomer on these receptors. Finally, L-PCA (10(-5) to 10(-4) M) was unable to antagonize the specific binding of all the other radioligands to their respective receptors and binding sites. D-PCA did not significantly interact with excitatory amino acid receptors or with any of the other sites studied here.
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PMID:Investigations on the binding properties of the nootropic agent pyroglutamic acid. 197 55

We have isolated a cold-sensitive mutant of Saccharomyces cerevisiae in which the first step of mRNA splicing is inhibited. The growth and splicing defects are recessive and cosegregate, thus defining a single essential gene (PRP28). The wild-type PRP28 gene was cloned, and sequence analysis reveals extensive homology to a family of proteins that are thought to function as ATP-dependent RNA helicases. The cold sensitivity is caused by a glycine-to-glutamic acid change in a conserved sequence motif. Interestingly, double mutants containing conditional alleles of PRP28 and PRP24, which encodes a U6 snRNA-binding protein, are inviable. In addition, a suppressor of prp28-1 is a mutant allele of PRP8, which encodes a U5 protein, thus linking PRP28 with U5. These data are consistent with a scenario in which PRP28 acts to unwind the U4/U6 base-pairing interaction in the U4/U6/U5 snRNP, facilitating the first covalent step of splicing.
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PMID:A cold-sensitive mRNA splicing mutant is a member of the RNA helicase gene family. 201 88

Experiments were conducted to determine if both electrical and chemical stimulation of the ventromedial hypothalamic nucleus (VMH) could activate brown adipose tissue (BAT) thermogenesis. Age-matched, room-acclimated (21 degrees C) and cold-acclimated (4 degrees C for 3 weeks prior to testing) male Sprague-Dawley rats were given unilateral electrical or chemical stimulation to the VMH by way of a 'chemotrode apparatus'. The devised 'chemotrode' allowed both electrical stimulation (insulated piano wire stimulating electrode) and chemical stimulation (23 gauge stainless steel intracranial cannula of equal length) to be performed at the same VMH site using a common 19 gauge stainless steel outer guide tube. The first unilateral VMH electrical stimulation (0.5 ms pulse, 50 Hz and 120 microA for 30 s) caused no significant rise in interscapular brown adipose tissue temperature (TIBAT) colonic (Tc) or tail surface temperatures (Tt), compared to respective prestimulation control values in rats acclimated to 21 degrees C. In the 4 degrees C-acclimated group the first VMH electrical stimulation caused a significant rise in IBAT temperature. L-Glutamate administration to the same VMH site (60 nmol in 600 nl volume) also caused a significant increase in IBAT temperature in the 4 degrees C but not the 21 degrees C-acclimated rats. The rise in IBAT temperature following the L-glutamate injection to the 4 degrees C-acclimated group was similar to that found following the first electrical stimulation to this group. Interestingly, a second unilateral electrical stimulation of the VMH to 4 degrees C-acclimated rats could not evoke a similar increase in IBAT temperature suggesting that overall L-glutamate was acting in vivo as an excitotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Brown adipose tissue thermogenesis is activated by electrical and chemical (L-glutamate) stimulation of the ventromedial hypothalamic nucleus in cold-acclimated rats. 222 17

Nephrocalcin is a urinary glycopeptide that may be a physiological inhibitor of nephrolithiasis. Monomeric nephrocalcin purified from ethylenediaminetetracetic acid-treated urine is 14,000 daltons. Compositional analyses indicate that nephrocalcin is 10 per cent carbohydrate by weight and that 25 per cent of the amino acid residues are acidic (glutamic acid, aspartic acid and gamma-carboxyglutamic acid). Nephrocalcin binds reversibly to calcium oxalate crystals with a dissociation constant of about 0.5 microM. The high collapse pressure of nephrocalcin, 41.5 dynes per cm., measured for a monolayer at the air-water interface, suggests a highly organized structure in which hydrophilic and hydrophobic regions occupy separate regions on the surface of the inhibitor. Nephrocalcin contains the unusual amino acid, gamma-carboxyglutamic acid. Nephrocalcin isolated from urine of stone formers and from kidney stones does not contain gamma-carboxyglutamic acid and it has altered surface properties compared to normal nephrocalcin. The presence of the gamma-carboxyglutamic acid modification and the ability to form stable films with high collapse pressures may be important factors enabling nephrocalcin to prevent stone formation in vivo. The blood of cold water fishes contains antifreeze glycopeptides and/or peptides to prevent it from freezing. The structure of one such antifreeze peptide and its interactions with the crystal lattice of hexagonal ice are discussed as a model for how nephrocalcin might interact with calcium oxalate crystals and arrest their growth in urine.
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PMID:Protein inhibitors of crystal growth. 264 34

Two groups of patients subjected to radical correction of Fallot's tetrad and defects of interventricular septum were investigated to ascertain whether the addition of glutamic acid to blood cardioplegic perfusate could improve preservation of myocardial ATP during cardiac arrest. In the control group (17 patients) the myocardial protection was performed by repeated infusions of cold blood potassium cardioplegic solution; in the 2nd group (24 patients) cardioplegic perfusate containing glutamic acid (20 mmol/l) was used. Left ventricular biopsies were taken during the first minute after cross-clamping of the aorta and before the release of the aortic clamp to determine ATP, glutamate and lactate. The cross-clamping time averaged 32 min in both groups. In the patients of the control group the losses of ATP correlated with the decrease in glutamate during the clamping period. A maintenance of a higher myocardial glutamate content by glutamate-containing cardioplegic perfusate prevented ATP fall or increased its level in patients of the 2nd group. There was no significant difference in lactate levels between the two groups by the end of the cardiac arrest. We conclude that enrichment of blood cardioplegic solution by glutamic acid, which may act as a substrate for anaerobic energy production, provides more effective myocardial protection during ischemic heart arrest.
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PMID:Glutamate-blood cardioplegia improves ATP preservation in human myocardium. 289 Mar 48

The effect of pharmacological stimulants and prescriptions on the thermal status of man and their possible use to extend the exposure to the cold environment were investigated. The effectiveness of the following drugs and prescriptions was assessed: sydnocarb, phenamine, indopan; glutamic acid + lagochilus + ephedrine; sydnocarb + glutamic acid (sydnogluton); ephedrine + glutamic acid + strychnine. The test subjects were kept in air (in a thermal chamber) at -20 degrees C or in water at 0 to 2.5 degrees C (resting or swimming). The most effective treatment was provided by sydnocarb (effective doses were 10 mg X 2 or 30 mg X 5 in air or water, respectively) and sydnogluton (sydnocarb 30 mg + glutamic acid 0.25 g X 5 in cold water). When compared to placebo, sydnocarb (or sydnogluton) assured better thermal parameters of the body in cold water and longer (by 2-6 hrs) exposure which increased to 20 hrs.
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PMID:[Pharmacologic correction of the effect of cold on man]. 290 80


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