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

Embryos (8-16 cell) were obtained from random bred albino mice (6-8 weeks old) that were induced to superovulate by injections of 5 I.U. PMSG and 5 I.U. hCG given 48 hr apart. Embryos were exposed to intracellular cryoprotecting medium (glycerol 10%, 1-2 propanediol 20% in PBS) for 10 min and then transferred to extracellular vitrification medium (25% glycerol, 25% 1-2 propanediol in PBS). Vitrification medium containing embryos, and diluent (1 M sucrose) were loaded in a straw and immediately plunged into liquid N2. After thawing at 20 degrees C, the contents of the straw were mixed by shaking (1 step dilution) and emptied in a petri dish. After 3 washings in culture medium the embryos were kept in CO2 incubator for further development. In 3-step dilution procedure the dilution of cryoprotectants was done in 0.5 and 0.25 M sucrose before culture. Embryos in 3-step dilution of cryoprotectants exhibited high survival as compared to 1-step dilution (20.23% vs 6.55%).
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PMID:Cryopreservation of mouse embryos at -196 degrees C by vitrification. 280 16

Factors affecting germ tube formation in Candida albicans at suboptimal temperatures were investigated. Candida albicans formed germ tubes between 22 and 30 degrees C in solution when incubated without shaking, in the presence of bicarbonate (2 mg mL-1). Other conditions depended on the inducer used. Proline could induce germ tube formation optimally only when its concentration was between 200 and 400 mM. A concentration of 0.05 mM N-acetylglucosamine was sufficient to induce germ tube formation. N-Acetylglucosamine could induce germ tube formation at 30 but not at 25 degrees C. N-Acetylglucosamine induced germ tube formation was most reproducible when the cells were first starved by incubation in water for 16-24 h at 20 degrees C. Germ tubes induced by proline could be formed at pH values between 3.8 and 9.0 at 30 degrees C, but only between 7.0 and 7.5 at 25 degrees C. The addition of 0.05 to 5 mM glucose to a 5 mM proline induction solution allowed germ tube formation at 30 but not at 25 degrees C. Glucose (400 mM) did not suppress germ tube formation at 30 degrees C but only 5 mM was sufficient to cause a 65% suppression at 25 degrees C. The results show the importance of CO2 and (or) bicarbonate to the induction of germ tube formation and are consistent with the metabolism of the inducer.
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PMID:The requirements for bicarbonate and metabolism of the inducer during germ tube formation by Candida albicans. 285 98

The influence of alpha-melanocyte stimulating hormone (alpha-MSH) and beta-endorphin (beta-END) on the secretion of somatostatin (SRIF) from the median eminence (ME) was studied using an in vitro incubation system. The MEs from adult male rats were first preincubated at 37 degrees C for 30 min with constant shaking in 0.4 ml of Krebs-Ringer bicarbonate-glucose buffer (pH 7.4) containing bacitracin in an atmosphere of 95% O2/5% CO2. Medium was discarded and replaced by medium containing different doses of alpha-MSH, beta-END, or a fixed dose of alpha-MSH (10(-7) M or 10(-9) M) plus beta-END at various concentrations. By themselves alpha-MSH and beta-END did not alter basal SRIF release, but in the presence of alpha-MSH (10(-7) M) beta-END stimulated somatostatin release. This effect was significant at concentrations of beta-END of 10(-8) M and higher. The permissive effect of alpha-MSH was observed at a concentration as low as 10(-9) M, but in this case the stimulatory effect of beta-END became evident only at higher doses tested (10(-7) M). It is suggested that alpha-MSH and beta-END participate in the modulation of SRIF release. By themselves beta-END and alpha-MSH did not affect basal release of SRIF but in the presence of alpha-MSH, beta-END had a stimulatory effect on SRIF release. The mechanism for this interaction is unknown. The results are consistent with the possibility that beta-END neurons have stimulatory and inhibitory effects on SRIF release and that alpha-MSH, by blocking the inhibitory components, discloses the stimulatory effect of beta-END on SRIF release.
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PMID:Alpha-melanocyte stimulating hormone discloses a stimulatory effect of beta-endorphin on somatostatin release. 288 55

Experiments were performed in vitro to examine the possible role of calcium and calmodulin in GRF-induced somatostatin (SRIF) release from the median eminence. Adult male rats were used as tissue donors. The median eminences were first prestimulated in 0.4 ml Krebs Ringer bicarbonate glucose buffer (pH 7.4) containing bacitracin at 37C in an atmosphere of 95% O2, 5% CO2 with constant shaking for 30 min. When calcium was omitted, this medium was used during the prestimulation and stimulation periods. After prestimulation, the medium was discarded and replaced by medium containing the different substances to be tested (GRF, EGTA, calcium channel blockers, and calmodulin inhibitors). The stimulation of SRIF release induced by 10(-10) M GRF was not inhibited by omission of extracellular calcium or when the remaining CA+2 was chelated with 10(-4) M EGTA. The calcium channel blockers, nifendipine and verapamil (10(-6) M), failed to alter the increase of SRIF release induced by rGRF. Three calmodulin inhibitors were employed to examine the possible influence of calmodulin on GRF-induced SRIF release. Trifluoperazine (10(-6) M), triflupromazine (10(-6) M) and penfluridol (10(-7) M) had an inhibitory effect on the stimulation of SRIF release induced by GRF and failed to alter resting release. Thus, GRF can evoke SRIF release independently of extraterminal Ca+2 concentration and Ca+2 influx into the nerve terminals, but the releasing process involves translocation of Ca+2 from intracellular stores. The inhibitory effect of the calmodulin inhibitors on GRF-induced SRIF release, suggests that the translocated Ca+2 must bind to calmodulin in order to release SRIF.
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PMID:Calmodulin dependence of somatostatin release stimulated by growth hormone-releasing factor. 289 60

Cells of Euglena gracilis Klebs var. bacillaris Cori mutant W3BUL grown in darkness on Hutner's pH 3.5 medium without agitation accumulate wax ester. These cells have undeveloped proplastid remnants characteristic of this mutant. If these cells are transferred to an inorganic medium and bubbled with 2-3% CO2 in air, the wax disappears and the proplastid expands and develops in darkness to form prolamellar bodies and membrane vessicles within 96 h. No further development takes place in darkness, but if these cultures are illuminated at 96 h formation of prothylakoids is observed. Thus the wax ester accumulated during growth can be used subsequently to support proplastid development up to the prolamellar body stage, but the formation of prothylakoids is strictly light-dependent. Development in this system takes place at a slower rate than in cells grown with shaking and lacking wax which are transferred to resting medium. As previously shown, all of proplastid development requires light under these conditions. It is suggested that the oxygen-requiring utilization of wax in darkness can provide energy and metabolites for a part of proplastid development but the later steps in these cells, or the entire development in cells lacking wax is supported by paramylum degradation which is strictly light-dependent. However, a specific light reaction required for prothylakoid organization is not ruled out.
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PMID:Light-independent and dependent phases of proplastid development in Euglena gracilis W3BUL. 311 30

Directions for pre-analytical handling of ampules of two commercially available aqueous quality-control products (contrlL and G.A.S.) contain vague instructions such as "store at room temperature" and "shake vigorously" before analysis. We examined the effect of different storage temperatures (25, 31, and 38 degrees C) and shaking rate (one, two, and four shakes per second) on pH and blood-gas results. For both products, increasing the storage temperature significantly decreased pO2 results, the magnitude of the bias being greatest for those solutions with the highest O2 tensions. However, increasing the shaking rate partly offset this bias. Increasing storage temperature also decreased results for pCO2 and increased results for pH for both manufacturers' ampules with the highest CO2 tensions, and this bias was not offset by increasing the shaking rate. We conclude that both storage temperature and shaking rate must be precisely defined and carefully monitored before these products are used in a quality-control program.
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PMID:Effect of storage temperature and shaking rate on pH and blood-gas results for two quality-control products. 313 48

Conditions influencing the survival of Campylobacter jejuni in the natural aquatic environment have been determined. Release of Campylobacter spp. into natural waters by animal hosts is postulated to play a key role in the maintenance of viability and transmission of the organism in the environment. Laboratory flask microcosms containing filter-sterilized stream water were used to test C. jejuni for the ability to remain viable in simulated natural systems. The microcosms were compared with the biphasic and shaking broth procedures used routinely for growth of Campylobacter spp. in the research laboratory. The stream-water microcosms were analyzed to determine effects of temperature and aeration on the survival of a well-characterized C. jejuni strain isolated originally from a human campylobacteriosis patient. Morphological characteristics were evaluated by phase-contrast microscopy and scanning or transmission electron microscopy. Survival curves were quantified on the basis of plate counts, epifluorescent microscopy, optical density measurements, and direct viable counts associated with protein synthesis in the absence of DNA replication. A significant difference was observed between results of direct enumeration, i.e., direct viable counts or acridine orange direct counts, and those from spread plate cultures. In all cases, increasing temperature of cultivation resulted in decreased recoverability on laboratory media, due possibly to an increased metabolic rate, as analyzed by CO2 evolution in the presence of radiolabeled glutamate. Stream water held at low temperature (4 degrees C) sustained significant numbers of campylobacters for greater than 4 months. Microcosms, aerated with shaking, exhibited logarithmic decline in recoverable C. jejuni, while stationary systems underwent a more moderate rate of decrease to the nonculturable state.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Viable but nonculturable stage of Campylobacter jejuni and its role in survival in the natural aquatic environment. 376 58

Maximum growth of Campylobacter fetus subsp. jejuni, strain C-61, occurred when the cultures were incubated with shaking in atmospheres containing approximately 30% hydrogen, 5% oxygen, and 10% CO2. Suspensions of cells grown under these conditions consumed oxygen with formate as the substrate in the presence of 0.33 mM cyanide, which completely inhibited respiration with ascorbate-N,N,N',N'-tetramethyl-p-phenylenediamine and with lactate. Spectroscopic evidence with intact cells suggested that a form of cytochrome c, reducible with formate but not with lactate or ascorbate-N,N,N',N'-tetramethyl-p-phenylenediamine, can be reoxidized by a cyanide-insensitive system. Analysis of membranes from the cells showed high- and low-potential forms of cytochrome c, cytochrome b, and various enzymes, including hydrogenase, formate dehydrogenase, and fumarate reductase. The predominant carbon monoxide-binding pigment appeared to be a form of cytochrome c, but the spectra also showed evidence of cytochrome o. The membrane cytochromes were reduced by hydrogen in the presence of 2-heptyl-4-hydroxyquinoline-N-oxide at concentrations which prevented the reduction of cytochrome c with succinate as the electron donor. Reoxidation of the substrate-reduced cytochromes by oxygen was apparently mediated by cyanide-sensitive and cyanide-insensitive systems. The membranes also had hydrogen-fumarate oxidoreductase activity mediated by cytochrome b. We conclude that C. fetus jejuni has high- and low-potential forms of cytochrome which are associated with a complex terminal oxidase system.
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PMID:Aerobic and anaerobic respiratory systems in Campylobacter fetus subsp. jejuni grown in atmospheres containing hydrogen. 628 61

The present study was carried out to characterize the spontaneous release of LH and FSH from the pituitary gland of infant rats in an in vitro system. In addition, the responsiveness of their pituitary glands to synthetic LHRH in vitro was examined. Wistar-Imamichi male and female rats, aged between 1 and 21 days and androgenized female rats at 7 and 21 days of age were used. One-day-old female rats were androgenized by a subcutaneous injection of 1 mg of testosterone propionate. Animals were killed by decapitation, trunk blood was collected, and the pituitary gland was dissected free and weighed. Pituitaries were placed in 9 ml-test tube with 2 ml Krebs-Henseleit solution and incubation was carried out in a shaking incubator for 6 hours at 37 degrees C under the gassing of 5% CO2 and 95% O2. After preincubation for 15 min, medium was replaced with 2 ml fresh medium and LH and FSH concentrations released during the first 3 hr-incubation period were assessed as for the spontaneous release and the second 3 hr-incubation period assessed for the response to LHRH (10(-6)M) stimulation. In an experiment, time course changes of the spontaneous release of LH and FSH were studied using 7-day-old rat pituitaries. An aliquot of 0.5 ml of medium was taken at 30, 60, 120 and 180 min during the incubation. Gonadotropin contents in the pituitaries were determined by adding the residue in the pituitary gland and the amounts released into medium. Spontaneous release of LH and FSH increased with age in both male and female rats, and the released amounts of LH as well as FSH in female rats tended to be higher than those in males at 1, 3, 7 and 21 days of age examined. But significant sex differences in the spontaneous release of LH and FSH were only seen at 21-day-old; Spontaneous release of LH in female rats was 7 times higher than that in age-matched males. Serum LH and FSH concentrations in female rats were significantly higher than those in males at all ages examined, except the LH level at 1-day-old. In contrast to LH, age and sex differences in the magnitude of the spontaneous release of FSH from the pituitary paralleled with the age and sex differences in serum FSH concentrations.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Sex and age differences in the spontaneous release of gonadotropins from immature rat pituitary glands in vitro]. 642 31

Thirty-four chemicals-diverse in structure, postulated mechanisms of action, and primary target organs--were tested for cytotoxic response in isolated hepatocyte suspensions from young male Sprague-Dawley rats. Hepatocytes were incubated in the presence and absence of the test chemicals in closed vessels fitted with side arms for serial sampling for up to 5 h at 37 degrees C with gentle shaking under an O2:CO2 (95:5) atmosphere. The parameters evaluated were glutamate-oxaloacetate transaminase and lactate dehydrogenase release from the cells, Trypan blue exclusion, cell count, urea synthesis capability, and steady-state ATP levels. All chemicals cytotoxic in animals following single or short-term repeated exposures caused statistically significant changes in one or more of these parameters in the 0.01-10-mM concentration range. Dimethylnitrosamine and thioacetamide were not as potent in the isolated cell system as expected from their in vivo hepatotoxicity, and the quantitative changes produced with thioacetamide in the hepatocytes were marginal, even at 10 mM. The solvents tested--ethanol, acetone, dimethyl sulfoxide (DMSO), and propylene glycol--were without effect. These results indicate that isolated hepatocyte suspensions are useful for the identification of cytotoxins in general and hepatotoxins in particular, but that their capability for yielding a quantitative index of cytotoxic potential for diverse chemical species remains to be demonstrated.
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PMID:Response of isolated hepatocytes to organic and inorganic cytotoxins. 662 Mar 99


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