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)

The pathogenesis of hepatic encephalopathy has been investigated in a two-stage devascularization model in the rat with portavacal shunt and hepatic artery ligation. There is a significant increase in brain octopamine and phenylethanolamine and a decrease in brain norepinephrine (NE) 6 to 9 hours after hepatic artery ligation. The depletion of NE seems the sequel of diminished synthesis in the presence of an unaltered turnover rate, due to a blockade of tyrosine hydroxylase either by accumulation of false neurochemical transmitters or by phenylalanine. It is most marked in the cortex and midbrain. The high-energy phosphate compounds, ATP, phosphocreatine and glucose-6-phosphate are not diminished in hepatic coma, nor is glucose, indicating that other mechanism are involved in the pathogenesis of metabolic state by the increased ammonia level. "intestinal sterilization" and total colectomy have no significant effect on the ammonia level, but cause a decrease in the level or aromatic precursor amino acids in the plasma and brain, with normalization of the level of cerebral transmitters. These results permit the formulation of a unified concept of the hepatic coma syndrome and its clinical manifestations such as flapping tremor, the hyperdynamic cardiovascular state and the hepatorenal syndrome. Moreover, they form the basis for the introduction of a new therapeutic principle in the management of hepatic encephalopathy by L-dopa or modified amino acid solutions, which act by altering the central and peripheral neurotransmitters.
 ...
PMID:[Cerebral manifestations in the hepatic coma syndrome (author's transl)]. 0 92

The thermotolerant yeast Candida tropicalis, strain T-20, was cultivated on a chemically defined medium with glucose or malt wort in flasks with shaking at three temperatures: optimal (36degreesC), supraoptimal (38degreesC) and submaximal (41degreesC). An increase of temperature within these limits caused an increase in ATP content in yeast cells and a decrease in phosphohydrolase (ATPase) activity.
 ...
PMID:[ATP content in Candida tropicalis cells growing at different temperatures]. 13 53

Red blood cells (RBC) were obtained from 5 whole blood units by centrifugation and were purified using a simple washing procedure. Hematocrit and HES concentration in the 108-ml samples to be frozen were adjusted to 40% (v/v) and 12% (w/w), respectively. Cooling was performed by submerging into liquid nitrogen using containers to generate a flat sample geometry (3 mm thickness). After thawing in a shaking water bath, HES and free hemoglobin were removed in a simple washing step. To investigate the influence of the resuspension medium, the RBC were transferred into freshly drawn autologous plasma and into Locke's solution. Survival after thawing in terms of saline stability reached 86.3 +/- 2.3%. The cryopreservation procedure caused no major changes with regard to osmotic fragility, 2,3-DPG or intracellular Na+ and K+. ATP was reduced by 16%, but this had completely recovered after 3 h resuspension in autologous plasma. Some morphological changes present after thawing (e.g. stomatocytes, echinocytes) also recovered after 1.5 h. In conclusion, those RBC which survived the preservation process can be considered to be fully viable with regard to the parameters investigated.
 ...
PMID:[Cryopreservation of human erythrocytes with hydroxyethyl starch (HES)--Part 2: Analysis of survival]. 128 9

A protocol for the biochemical study of platelet stored for transfusional use at 22 degrees C and under continuous shaking in a plastic bag highly permeable to gases and with a suitable area/volume ratio, is described. Plasmatic dextrose, lactic acid, lactic dehydrogenase activity, cellular ATP and malonyldialdehyde were monitored during the storage, as well as some acid-base indexes namely: pH, pCO2, HCO3-, pO2. The platelet functional status was checked as aggregating power induced by ADP and collagen and by beta-thromboglobulin release. The results obtained are indicative of a discrete maintenance of aerobic metabolism by platelets which are able to give up CO2 and take up O2 so that the plasmatic pH is constant during the storage. However, the malonyldialdehyde increase suggests that platelets become increasingly susceptible to peroxidative attacks. The aggregating response was dramatically reduced even on the third day of storage. The data obtained point out that, under the conditions reported, platelets can be transfused up to the third day of storage.
 ...
PMID:Biochemical and functional changes of platelet stored for transfusional use. 244 9

Cultured cells often exhibit alterations in energy metabolism (increased glycolytic activity and decreased oxidative metabolism) during adaptation to the culture environment. The role of hypoxia as a mediator of these effects was examined by comparison of metabolism in primary rabbit renal proximal tubule (RPT) cultures maintained in stationary culture dishes (DISH), shaking Erlenmeyer flasks (SHAKE), and DISH cultures transferred back to SHAKE conditions (RESHAKE). Both oxidative metabolism and transport capacity were fully preserved in SHAKE cultures over a 24-h period. In contrast, within 6 h, DISH cultures exhibited a continuous decline in transport-dependent and -independent oxygen consumption, respiratory capacity, and ATP and K+ contents. The loss of oxidative metabolism in DISH cultures was accompanied by stimulation of lactate production, detectable within 1 h after plating. Comparison of metabolic properties of DISH cultures to those of RPT exposed to graded levels of hypoxia suggested that medium oxygen tensions may be as low as 1-3% in DISH cultures. RESHAKE cultures exhibited metabolic properties comparable to those of SHAKE cultures, indicating reversibility of DISH culture metabolism on reoxygenation. We concluded that DISH cultures rapidly become hypoxic as a consequence of static culture conditions. Shaking suspension cultures may provide a more metabolically appropriate model for long-term in vitro studies.
 ...
PMID:Glycolytic and oxidative metabolism in primary renal proximal tubule cultures. 276 94

1. The metabolism of mouse thioglycollate-elicited peritoneal macrophages was studied in culture for up to 96 h. 2. The rates of glycolysis, lactate formation and glutamine utilization were approximately linear with time for at least 80 h of culture. 3. The rates of glucose and glutamine utilization by cultured macrophages were approx. 500 and 90 nmol/h per mg of protein respectively. This rate of glucose utilization is at least 50% greater than that previously reported for macrophages during 60 min incubation in a shaking flask; and it is now increased by addition of glutamine to the culture medium. The rate of glutamine utilization in culture is similar to that previously reported for macrophages during 60 min incubation. The major end-product of glucose metabolism is lactate, and those of glutamine metabolism are CO2, glutamate, ammonia and alanine. 4. Oleate was utilized by these cells: 14C from [14C]oleate was incorporated into CO2 and cellular lipid. The highest rate of oleate utilization was observed when both glucose and glutamine were present in the culture medium. The presence of oleate in the culture medium did not affect the rates of utilization of either glucose or glutamine. Of the [14C]oleate incorporated into lipid, approx. 80% was incorporated into triacylglycerol and only 18% into phospholipid. 5. The turnover rate for the total ATP content of the macrophage in culture is about 10 times per minute: the value for the perfused isolated maximally working rat heart is 22. This indicates a high metabolic rate for macrophages, and consequently emphasizes the importance of the provision of fuels for their function in an immune response.
 ...
PMID:Rates of utilization of glucose, glutamine and oleate and formation of end-products by mouse peritoneal macrophages in culture. 277 7

Phosphocellulose paper has been found to be the paper of choice in assaying protein kinase activities using [gamma-32P]ATP by the trichloroacetic acid method of precipitation and washing. A study of binding of ATP of increasing concentrations at constant specific activity with Whatman 3MM or ATP-coated Whatman 3 MM papers (in vogue) versus phosphocellulose paper (proposed here) has shown that the latter has the least affinity for ATP when washing is done with either trichloracetic acid or trichloroacetic acid containing pyrophosphate. In an experiment where the placental cytosolic protein kinase was serially diluted, the phosphocellulose paper was found to give higher signal/noise ratios at all dilutions studied compared to the other two papers. With regard to the technological side of washing the papers, we have found that the traditional method of cutting papers into small squares before loading the samples is perhaps not the best. Instead, we propose the use of a flat sheet matrix for loading the samples because this method ensures uniformity of washing among the samples while shaking is performed on a simple shaker. In addition, the whole paper matrix can provide an almost instantaneous autoradiogram of hundreds of samples facilitating biochemical experimentation with protein kinases.
 ...
PMID:Protein kinase assay by paper-trichloroacetic acid method: high performance using phosphocellulose paper and washing an ensemble of samples on flat sheets. 343 97

Growth of phase alpha 3a on stationary phase Vibrio cultures requires micro-aerophilic conditions and is inhibited by aeration. Since pre-conditioning of the bacteria by allowing them to stand for 24 h after shaking for 3 d is an important aspect of the stationary phase phage growth system, various physiological and morphological characteristics of the stationary phase cells during the transition from shaking to standing were investigated. Shaken stationary phase cells were less viable and more sensitive to ultraviolet irradiation and heat than standing stationary phase cells. During pre-conditioning the small, non-flagellated cells present in shaken stationary phase cultures underwent morphological changes and became large, flagellated rods which resembled exponential phase cells. The transition of stationary phase cells from shaking to standing was associated with a marked increase in total RNA synthesis but a rapid and large decrease in total protein synthesis. Intracellular concentrations of ATP in shaken stationary phase cells were 53% lower than those in standing stationary phase cells. Studies on leucine uptake indicated that its transport was inhibited by isoleucine and that the major part (90%) of the total leucine uptake was due to a shared system for uptake of both amino acids. Shaken stationary phase cells transported less leucine than standing stationary phase cells. Inhibition of phage growth in aerated stationary phase cultures was not due to the prevention of phase absorption by shaking. It is suggested that the observed differences between shaken and standing stationary phase cells could be due to aeration affecting the template specificity of the Vibrio RNA polymerase.
 ...
PMID:Physiological and morphological characteristics of stationary phase vibrio cells able to support phase growth. 616 43

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.
 ...
PMID:Response of isolated hepatocytes to organic and inorganic cytotoxins. 662 Mar 99

The mutagenicity of N,N-dimethylaminoazobenzene (DAB) is difficult to demonstrate in Ames' test. Usually there are specific requirements for activation by post-mitochondrial supernatant fluid (S-9) from Aroclor-treated rat livers and the pre-incubation modification of the test. Results from this laboratory suggest, however, that pre-incubation is not essential; also, that, contrary to published reports, concentrations of S-9 greater than 10% in S-9 mix do not reduce the mutagenic response. Induction of enzyme activity well above normal levels, on the other hand, is necessary, but this requirement can be substituted by the addition of norharman. If a competent S-9 mix is used, pre-incubation with or without shaking does not alter the response and supplementation with ATP or NADH similarly has no effect. It is concluded that interlaboratory differences in the ability to demonstrate DAB mutagenicity reflect differences in the level of induction of liver enzymes and, possibly, the concentration of endogenous co-factors.
 ...
PMID:Factors affecting the response of N,N-dimethylaminoazobenzene in the Ames microbial mutation assay. 681 79


1 2 3 4 Next >>