Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Development of microbodies in Candida tropicalis pK 233 was studied mainly by electron microscopical observation. The yeast cells, precultured on malt extract, scarcely contained microbodies and showed very low catalase activity. When the precultured cells were transferred to a n-alkane medium and incubated with shaking, the number of microbodies increased and concomitantly the activity of catalase was enhanced. That is, both the area ratio of microbodies in the cell and the ratio of microbodies to cytoplasm in area increased significantly during the utilization of n-alkanes for 8 hrs. Localization of catalase in the microbodies was demonstrated cytochemically by use of 3,3'-diaminobenzidine, but other organella in the cell, except for vacuoles appearing in the early growth phase and mitochondria, were not stained with this reagent. Microbodies seemed to grow by division. Biogenesis of microbodies in the yeast cells is also discussed.
 ...
PMID:Development of microbodies in candida tropicalis during incubation in a n-alkane medium. 115 85

One-month-old male Sprague-Dawley rats were fed a basal vitamin E deficient diet with or without 50 ppm vitamin E supplementation for 7 months. The washed red cells were suspended in a saline-phosphate buffer, pH 7.4, that contained either 0, 0.011 or 0.055 M glucose and were incubated at 37 C with constant shaking. Catalase activity in the red cells of vitamin E deficient rats was decreased 74% (P less than 0.001) at the end of the 22-hour incubation, and only 9% of the initial value was retained at the end of 46 hours. In the red cells of the vitamin E supplemented group, 82% and 48% of catalase activity was retained at the end of 22 and 46 hours, respectively. Glucose in the medium significantly increased catalase activity during the early hours of incubation and retarded the enzyme inactivation at the end of 22 and 46 hours in both groups of animals. The activities of superoxide dismutase and glutathione peroxidase were not significantly altered by the presence of glucose or by the status of dietary vitamin E during the incubation. The results suggest that both glucose and dietary vitamin E provide protection against inactivation of catalase under the experimental conditions.
 ...
PMID:Glucose and dietary vitamin E protection against catalase inactivation in the red cells of rats. 720 46

To investigate the role of hydrogen peroxide in Cr(VI) toxicity in vivo toward bacterial cells, we examined the effect of Cr(VI), hydrogen peroxide, sodium azide, and mannitol on the viability of Escherichia coli. Bacterial cells were incubated for 1 h with shaking in the presence of Cr(VI), hydrogen peroxide, sodium azide as catalase inhibitor, and/or mannitol as radical scavenger. The colony-forming ability and double-strand DNA degradation were examined. The viability assays revealed that Cr(VI) toxicity depended on hydroxyl radicals generated in the reaction involving hydrogen peroxide and chromium. Moreover, incubation of E. coli cells with 10 mM Cr(VI) and 3 mM hydrogen peroxide caused the degradation of double-strand DNA in vivo, which was suppressed by the addition of mannitol. These results indicated that hydroxyl radicals generated in the incubation degraded DNA of E. coli cells, resulting in cell death. In the absence of added hydrogen peroxide, the intracellular concentration of hydrogen peroxide in E. coli was low (below 1 microM). A catalase-defective strain incubated in the absence of added hydrogen peroxide remained fully viable after 1 h but showed decreased viability after prolonged incubation (4-8 h). The addition of mannitol suppressed this decrease, suggesting that hydroxyl radicals may be involved in the expression of Cr(VI) toxicity even without added hydrogen peroxide.
 ...
PMID:Mechanism of chromium(VI) toxicity in Escherichia coli: is hydrogen peroxide essential in Cr(VI) toxicity? 759 39

Cu, Zn-superoxide dismutase (Cu,Zn-SOD), Mn-superoxide dismutase (Mn-SOD), catalase (CAT), peroxidase (POX), glutathione peroxidase(GP) and glutathione reductase (GR) activities were assayed in the brains of genetically selected neurological mutant rabbits pt and their controls. Paralytic tremor (pt) is a spontaneous mutation in rabbit that affects irregular and defective myelination of CNS. Antioxidant enzyme levels were different in three brain regions: brain hemispheres, cerebellum, and brain stem. In brain hemisphere and cerebellum of pt rabbits Mn-SOD and Cu, Zn-SOD activities were elevated. Catalase activity in brain hemispheres and peroxidase activity in the brain stem of pt rabbits were reduced. It was also noticed, that in the pt rabbit the ratio CAT/Cu, Zn-SOD was lower by 20% in the brain hemispheres and by 13% in the cerebellum and the ratio POX/Cu, Zn-SOD was lower by 31.8% in the brain stem. These findings indicated that pt mutations are associated with changes in the antioxidant defense system in the rabbit brain.
 ...
PMID:Antioxidant enzyme activities in different brain areas of the neurological mutant--pt rabbit. 870 86

To produce catalase-free uricase preparations, we constructed catalase-deficient strains from Escherichai coli MC1000 and MM294 and used them as recombinant host strains. The parent strains and catalase-deficient strains showed no differences in the growth characteristics by shaking culture in Erlenmeyer flasks. The catalase deficient strain derived from MC1000 transformed with the uricase expression plasmid pUT118 (strain SN0037) had growth characteristics and the uricase productivity comparable to those of the parent host strain MC1000 in fed-batch culture in a jar fermentor and no catalase activity was detected in cell-free extracts. However, the katG disrupted strains from MM294 carrying pUT118 had poor growth and their uricase productivities were low compared to those of the parent strain MM294. Using the strain SN0037, a catalase-free uricase preparation was obtained with fewer purification procedures and the final recovery of uricase activity was improved. The catalase-deficient E. coli host strain will be a suitable host for the production of the uricase, free of catalase activity, in high yield.
 ...
PMID:Construction of catalase deficient Escherichia coli strains for the production of uricase. 890 Oct 98

Platelets and coagulation are involved in the pathogenesis of blood-borne metastases. The aim of this study is to obtain more information about the mechanisms involved in the initial adhesion of tumor cells to endothelial cells. In short term experiments with tumor cells, suspended in the medium of cultured endothelial cells, we tested whether addition of both platelets and thrombin cause more tumor cell adhesion to endothelial cells, than when either platelets or thrombin are acting alone. HeLa cells or HT29 cells, prelabeled with radioactive 51Cr, human platelets, and thrombin were added to human endothelial cell cultures. Following 15 min of shaking at 37 degrees C, the percentage of tumor cell adhesion was calculated. The percentages of adhering tumor cells with the presence of both platelets and thrombin were greatly increased compared to controls. Addition of hirudin 2 min before thrombin lowered the adhesion percentage of tumor cells. Hirudin added immediately before and 2 min after thrombin gave only minor effects. When the endothelium was treated with superoxide dismutase, catalase, and mannitol, the adhesion of tumor cells was lowered with catalase and superoxide dismutase. The cause of tumor cell-endothelial cell interaction is probably complex. Our results show that activated platelets enhance the tumor cell adhesion, and that generation of active oxygen species may be important in the initial phase of the interaction.
 ...
PMID:Addition of both platelets and thrombin in combination accelerates tumor cells to adhere to endothelial cells in vitro. 911 26

Ethanol is metabolized in the brain by catalase/H2O2 to yield acetaldehyde and by an ethanol-inducible form of cytochrome P450 (P450 IIE1) in a reaction that yields oxygen radicals. Within the cytoplasm of serotonergic axon terminals these metabolic pathways together provide conditions for the endogenous synthesis of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline (1), by reaction of acetaldehyde with unbound 5-hydroxytryptamine (5-HT), and for the oxygen radical-mediated oxidation of this alkaloid. The major initial product of the hydroxyl radical (HO.)-mediated oxidation of 1 in the presence of free glutathione (GSH), a constituent of nerve terminals and axons, is 8-S-glutathionyl-1-methyl-1,2,3,4-tetrahydro-beta-carboline-5,6-dione (6). When administered into the brains of mice, 6 is a potent toxin (LD50 = 2.9 microg) and evokes episodes of hyperactivity and tremor. Compound 6 binds at the GABA(B) receptor and evokes elevated release and turnover of several neurotransmitters. Furthermore, the GABA(B) receptor antagonist phaclofen attenuates the behavioral response caused by intracerebral administration of 6. These observations suggest that 6 might be an inverse agonist at the GABA(B) receptor site. Accordingly, it is speculated that ethanol drinking might potentiate formation of 6 that contributes to elevated release of several neurotransmitters including dopamine (DA) and endogenous opioids in regions of the brain innervated by serotonergic axon terminals. Subsequent interactions of DA and opioids with their receptors might be related to the initial development of dependence on ethanol. Redox cycling of 6 (and of several putative secondary metabolites) in the presence of intraneuronal antioxidants and molecular oxygen to produce elevated fluxes of cytotoxic reduced oxygen species might contribute to the degeneration of serotonergic pathways. Low levels of 5-HT in certain brain regions of the rat predisposes these animals to drink or augments drinking. Accordingly, 6, formed as a result of ethanol metabolism in the cytoplasm of certain serotonergic axon terminals, might contribute to the initial development of dependence on ethanol, by mediating DA and opioid release, and long-term preference and addiction to the fluid as a result of the progressive degeneration of these neurons.
 ...
PMID:Putative oxidative metabolites of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline of potential relevance to the addictive and neurodegenerative consequences of ethanol abuse. 916 Jul 98

A gram-negative, rod- to oval-shaped, aerotolerant anaerobic bacterium was isolated from an anaerobic enrichment inoculated with sediment taken from below the cyanobacterial mat of a high-salinity pond near Bratina Island on the McMurdo Ice Shelf, Antarctica. The organism was positive for terminal oxidase and catalase and was motile by means of a polar flagellum. Optimal growth of anaerobic cultures occurred at 12 degrees C, at pH 6.5, and at an NaCl concentration of 3% (w/v). Of a variety of polysaccharides tested, only starch and glycogen supported growth. No growth was observed on cellulosic substrates and xylan, and the organism was unable to attack esculin. Monosaccharides and disaccharides, including the cyanobacterial cell-wall constituent N-acetyl glucosamine, were fermented. Per 100 mol of hexose, the following products (in mol) were formed: acetate, 60; formate, 130; ethanol, 56; lactate, 73; CO2, 15; and butyrate, 2. Propionate, ethanol, n-propanol, n-butanol and succinate were not detectable in the culture medium (< 1 mol per 100 mol of monomer). Hydrogen was not detected in the head space (detection limit < 10(-5) atm). Growth yields in aerobic static liquid cultures were slightly higher than those in anaerobic culture, and fermentation favoured acetate at the expense of electron sink products. Growth was inhibited in aerobic shaking cultures, and the organism did not utilize nitrate or sulfate as electron acceptors. The G+C content of the DNA from the bacterium was 42.8 mol%. A phylogenetic analysis indicated that the organism is a member of the gamma-subgroup of Proteobacteria, but that it is distinct from other members of this group based on the sequence of its 16S rRNA gene, mol% G+C, morphology, and physiological and biochemical characteristics. It is designated as a new genus and species; the type strain is star-1 (DSM 10704).
 ...
PMID:Psychromonas antarcticus gen. nov., sp. nov., A new aerotolerant anaerobic, halophilic psychrophile isolated from pond sediment of the McMurdo ice shelf, antarctica 947 58

Scrapie, one of the prion diseases, is a transmissible neurodegenerative disease of sheep and other animals. Clinical symptoms of prion diseases are characterized by a long latent period, followed by progressive ataxia, tremor, and death. To study the induction of neurodegeneration during scrapie infection, we have analyzed the activities of various antioxidant enzymes and mitochondrial enzymes in cerebral cortex, brain stem, and cerebellum of scrapie-infected hamsters. The activity of mitochondrial Mn-superoxide dismutase (SOD) was decreased, while the activities of cytosolic Cu/Zn-SOD and catalase were not altered in infected brains. The activities of glutathione peroxidase and glutathione reductase were increased in scrapie-infected hamsters. The decreased activity of Mn-SOD might result in increasing oxidative stress in the mitochondria of infected brain; this concept is supported by our findings of a high level of lipid peroxidation, and low levels of ATPase and cytochrome c oxidase activity in the infected cerebral mitochondria. In addition, structural abnormalities of mitochondria have been observed in the neurons of hippocampus and cerebral cortex of infected brain. These results suggest that mitochondrial dysfunction caused by oxidative stress gives rise to neurodegeneration in prion disease.
 ...
PMID:Mitochondrial dysfunction induced by oxidative stress in the brains of hamsters infected with the 263 K scrapie agent. 975 61

The objective of this work was to study the production of catalase and nitrate reductase by staphylococci in order to understand their role in lipid oxidation during sausage manufacturing. Catalase and nitrate reductase were measured in resting cells and supernatants of staphylococci grown in different conditions. All staphylococci (except S. warneri) synthetized nitrate reductase. In static condition, the synthesis was maximal during exponential growth phase, whereas in shaking condition, the synthesis was maximal at the beginning of stationary phase. The production of nitrate reductase was increased in presence of nitrate, this effect was particularly important for the two S. carnosus strains which exhibited the highest activity. For all staphylococci, the production of catalase was maximal at the end of the exponential growth phase. The lowest amount of catalase was produced by S. warneri and the highest by S. carnosus. Only S. xylosus 873 and S. saprophyticus 852 released high amounts of catalase in the supernatant growth. Staphylococci produced higher amounts of catalase in shaking conditions. Addition of nitrate in the growth media favoured the synthesis of catalase, with a pronounced effect for S. carnosus. Nitrate also favoured the release of catalase.
 ...
PMID:Effect of nitrate and incubation conditions on the production of catalase and nitrate reductase by staphylococci. 1057 91


1 2 3 Next >>