Effects of remifentanil on the minimum alveolar concentration of isoflurane in dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effects of sildenafil on rectal sensitivity and tone in patients with the irritable bowel syndrome

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of processing on physical characteristics of diets with distinct levels of carbohydrates and lipids: the outcomes on the growth of pacu (Piaractus mesopotamicus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of monocrotaline on energy metabolism in the rat liver

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of salinity on ZOANTHUS SOCIATUS (Cnidaria: Anthozoa): Is low salinity a limiting factor?

Abiotic factors, such as variations on salinity, exert influence on the animal distribution in the intertidal zone, including zoanthids. This study evaluated the osmotic, morphological and ethological effects of salinity variations on tropical zoanthid Zoanthus sociatus. In order to analyze the hypothesis of osmotic conformation, the zoanthid was submitted to salinity stress. To estimate the osmotic capabilities of the species studied, specimens collected in beach rocks were taken alive to the laboratory and maintained in water collected from the site. The osmoregulatory ability of Z. sociatus was determined by measuring the hemolymph osmolality under various salinity conditions and comparing it to the medium osmolality. Zoanthid Z. sociatus is able to present osmotic conformation in hemolymph salinity in a wide range of external salinity values. The bleaching frequency was high in low salinities and the mortality rate was high after two days of experiment. This experiment shows for the first time the importance of osmotic conformation in a tropical zoanthid and discusses the role of low salinity as a limiting factor for survival and distribution of these important animals in tropical coastal reefs.

Effects of HCl on the ultrasound catalyzed TEOS hydrolysis as determined by a calorimetric study

The acid catalyzed and ultrasound stimulated hydrolysis of solventless tetraethoxysilane-water mixtures was studied at 39°C as a function of HCl added to the mixtures (log[HCl]-1 ranged from 0.8 to 2.0), The reaction was carried out in a specially designed device, in which a steady state heat flow is maintained, while sonication is taking place, if no reaction is expected to occur. The exothermal hydrolysis reaction causes an increasing temperature (ΔTt) as a function of the reaction time, t. The isothermal hydrolysis rate constant, k, has been evaluated from the experimental ΔTt versus t data, after corrections for the increasing temperature effects, by using a method resulting from our theoretical modeling based on a dissolution and reaction mechanism. The hydrolysis rate constant fits closely a k α [H+] law as expected for this kind of hydrogen-ion catalyzed reaction.

Effects of tunicamycin on glycoprotein antigens of Aspergillus fumigatus

Tunicamycin, which inhibits N-glycosylation of proteins, was used as a tool to determine the type of linkage which occurs in glycoprotein antigens of Aspergillus fumigatus. When A. fumigatus extracts were electrophoretically separated and blotted then probed with anti-Aspergillus patients' sera, differences in antigenic profiles were noted when tunicamycin-treated samples were compared with controls. Tunicamycin had no detectable effect on the cellular proteinases of A. fumigatus, most of which are glycosylated. Some enzymatic components were lacking when extracellular proteinases were compared with those of control samples. The major catalase component of A. fumigatus is a concanavalin A (Con A)-binding glycoprotein. In cultures grown in the presence of tunicamycin, partiallydeglycosylated catalase components were obtained which could be distinguished from the native catalase by their altered mobilities in polyacrylamide gels. The effect of deglycosylation on catalase antigens was monitored using an antiserum raised to a ConA-binding fraction of A fumigatus mycelium. These antibodies bound both to the native glycoprotein and the partially deglycosylated material. These latter two were largely unaffected when incubated with an antiserum raised to a non-ConA-binding fraction of A. fumigatus which is essentially carbohydrate free. The ability to produce partially-glycosylated antigens of A. fumigatus offers a model to study the effect of basic structural modifications on both the enzymatic and antigenic activities of these molecules.

Circadian time-dependent effects of fencamfamine on inhibition of dopamine uptake and release in rat striatal slices

Fencamfamine (FCF) is a central stimulant that facilitates central dopaminergic transmission through inhibition of dopamine uptake and enhanced release of the transmitter. We evaluated the changes in the inhibition of uptake and the release of striatal [ 3H]-dopamine at 9:00 and 21:00 h, times corresponding to maximal and minimal behavioral responses to FCF, respectively. Adult male Wistar rats (200-250 g) maintained on a 12-h light/12-h dark cycle (lights on at 7:00 h) were used. In the behavioral experiments the rats (N = 8 for each group) received FCF (3.5 mg/kg, ip) or saline at 9:00 or 21:00 h. Fifteen minutes after treatment the duration of activity (sniffing, rearing and locomotion) was recorded for 120 min. The basal motor activity was higher (28.6 ± 4.2 vs 8.4 ± 3.5 s) after saline administration at 21:00 h than at 9:00 h. FCF at a single dose significantly enhanced the basal motor activity (38.3 ± 4.5 vs 8.4 ± 3.5 s) and increased the duration of exploratory activity (38.3 ± 4.5 vs 32.1 ± 4.6 s) during the light, but not the dark phase. Two other groups of rats (N = 6 for each group) were decapitated at 9:00 and 21:00 h and striata were dissected for dopamine uptake and relase assays. The inhibition of uptake and release of [ 3H]-dopamine were higher at 9:00 than at 21:00 h, suggesting that uptake inhibition and the release properties of FCF undergo daily variation. These data suggest that the circadian time-dependent effects of FCF might be related to a higher susceptibility of dopamine presynaptic terminals to the action of FCF during the light phase which corresponds to the rats' resting period.

Cumulative effects of vinasse on the characteristics of red-yellow latosols under cerrado vegetation

Vinasse, a liquor effluent from the alcohol and sugar making industry, was applied annually for twelve years to medium-textured red-yellow latosols under cerrado vegetation sensu stricto, to study the environmental impacts on the biotic and abiotic factors. Four plots were established of which two acted as control and the other two received annual doses of vinasse. The studies were begun in 1980 when the first annual dose of 20 L m-2 year-1 was added to the soil without removing the top scrub layer. Theses doses were added to the soil until 1983, but in 1984 the doses were increased to 50 L m-2 year-1 and used until 1991. Soil samples were taken at a depth of 15 cm every three months from 1987 to 1991. Twenty seven environmental variables in the vinasse-treated and untreated plots were studied. These factors consisted of different enzymatic activities, a number of filamentous fungi, bacteria, actinomycetes and other micro-organisms, nutrients and some micro-climatic factors. The results obtained were statistically analyzed using the Tukey test, Pearson correlation and variance test methods with replicates and three factors. Matrices were determined using the correlation coefficient method and were compared with those of earlier published studies in the same area. The comparison of the results helped characterize changes in the environmental factors studied and in the correlation between them, after using annual cumulative doses of vinasse. Positive effects were observed only for the first six years of this application but vinasse had negative effects after the seventh year. It is concluded that medium-textured red-yellow latosols cannot be treated with vinasse for proloned periods.

Effects of cyclosporine on adriamycin induced nephropathy

The effect of cyclosporine on adriamycin nephropathy was studied over both short (6 weeks) and long (26 weeks) periods. In the short-term study, cyclosporine was introduced 2 weeks after nephritis induction and in the long-term study, 14 weeks after the first adriamycin injection. The animals with adriamycin nephropathy treated with cyclosporine, studied for 6 weeks, developed proteinuria with increased renal size and glomerular area. The nephrotic animals treated with cyclosporine showed less proteinuria than the nephrotic control animals. There were no differences in glomerular area, creatinine clearance or serum creatinine and kidney weight between the treated nephrotic group and the health control group. The nephrotic animals, studied for the longer period, developed intense proteinuria, decreased creatinine clearance, glomerular necrosis and sclerosis, severe tubulointerstitial nephritis, increased hydroxyproline concentration and tubulointerstitial area. No difference was observed between the nephrotic animals treated with cyclosporine and those not treated. In conclusion, Cyclosporine A reduced proteinuria, glomerular hypertrophy and kidney weight in rats with short-term nephropathy but had no effect on the established nephropathy.

Effects of ethanol on human visual evoked potentials

Studies of the effect of ethanol on human visual evoked potentials are rare and usually involve chronic alcoholic patients. The effect of acute ethanol ingestion has seldom been investigated. We have studied the effect of acute alcoholic poisoning on pattern-reversal visual evoked potentials (PR-VEP) and flash light visual evoked potentials (F-VEP) in 20 normal volunteers. We observed different effects with ethanol: statistically significant prolonged latencies of F-VEP after ingestion, and no significant differences in the latencies of the PR-VEP components. We hypothesize a selective ethanol effect on the afferent transmission of rods, mainly dependent on GABA and glutamatergic neurotransmission, influencing F-VEP latencies, and no effect on cone afferent transmission, as alcohol doesn't influence PR-VEP latencies.

Protein Deficiency Attenuates the Effects of Alloxan on Insulin Secretion and Glucose Homeostasis in Rats

We have investigated the effect of alloxan on insulin secretion and glucose homeostasis in rats maintained on a 17% protein (normal protein, NP) or 6% protein (low protein, LP) diet from weaning (21 days old) to adulthood (90 days old). The incidence of alloxan diabetes was higher in the NP (3.5 times) than in the LP group. During an oral glucose tolerance test, the area under serum glucose curve was lower in LP (57%) than in NP rats while there were no differences between the two groups in the area under serum insulin curve. The serum glucose disappearance rate (Kitt) after exogenous insulin administration was higher in LP (50%) than in NP rats. In pancreatic islets isolated from rats not injected with alloxan, acute exposure to alloxan (0.05 mmol/L) reduced the glucose- or arginine-stimulated insulin secretion of NP islets by 78% and 56%, respectively, whereas for islets from LP rats, the reduction was 47% and 17% in the presence of glucose and arginine, respectively. Alloxan treatment reduced the glucose oxidation in islets from LP rats to a lesser extent than in NP islets (23% vs. 56%). In conclusion, alloxan was less effective in producing hyperglycemia in rats fed a low protein diet than in normal diet rats. This effect is attributable to an increased peripheral sensivity to insulin in addition to a better preservation of glucose oxidation and insulin secretion in islets from rats fed a low protein diet.