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Biomedical subjects

M Parafita

Publications and source records attributed to M Parafita.

8 recordsLinked to original sources
PubMed1992

Oral fluorescein angiography and fluoroscopy: determination of plasma fluorescein levels and clinical application.

One hundred oral fluorescein angiographic explorations were performed in 85 patients of both sexes, mean age 55.57 years, and range 8 to 77 years. Fluorescein was administered as one 250-mg (15 patients) or 500-mg (70 patients) capsule per 15 kg of body weight. In 15 fasting and 15 postprandial patients administered 500-mg capsules, no significant differences by group were found between fluorescein plasma levels. Fundus fluorescence under slitlamp illumination was poor for patients receiving the lower dosage of fluorescein, whereas at the higher dosage it was visible in all but one patient. The best filters were found to be a Kodak-Wratten 47A for the excitation filter and Kodak-Wratten 8 for the barrier filter. With a conventional fundus camera and fluorescein angiography filters, good photographs were achieved in all cases. The integrity of the blood-retina barriers was explored for various chorioretinal pathologies.

Administration, Oral↗
PubMed1989

Effect of carbaryl on the respiration, glycolysis and gluconeogenesis in isolated liver cells.

The effects of 1-naphthyl-N-methylcarbamate (carbaryl) upon respiration, glycolysis and gluconeogenesis in isolated rat hepatocytes was studied. The carbaryl at 0.01; 0.1 and 1.0 mM were dissolved in 1% dimethylsulphoxide. Concentrations of carbaryl at 1.0 mM reduces oxygen consumption. The decrease in the metabolic production of CO2 is significant at even the lowest of the concentrations. The utilization of glucose and the endogenous production of lactic is unaffected by treatment with carbaryl. The net glycolytic flux is decreased. On the other hand, the carbaryl inhibits lactate-gluconeogenesis at all concentrations of substrate studied. Gluconeogenesis from fructose or pyruvate or alanine is also inhibited by carbaryl 1 mM. Carbaryl decreases the lactic dehydrogenase activity but this diminution is only significant for the greatest concentration assayed. The activity of glucose-6-phosphatase is enhanced by carbaryl, but the increase is only significant for 1 mM carbaryl. The glutamic-oxalacetic transferase cytoplasmic and mitochondrial activities are inhibited by 0.1 mM and 1.0 mM carbaryl. Carbaryl decreases glucose production by hepatic cells, and suggests that the carbaryl-induced hyperglycemia in the fasted animal would be due to deficiencies in the peripheral utilization of the glucose.

Animals↗
PubMed1986

Effect of lindane on brain monoamine metabolism.

The effect of the oral administration of the organochlorinate pesticide Lindane (gamma-hexachlorociclohexane) in doses of 30, 60 and 120 mg/kg on the cerebral metabolism of 5-HT and catecholamines in female rats was studied 24 hr after the administration of the pesticide. All the doses tested caused a decrease in the concentration of cerebral and free serum tryptophan, with no significant change in the cerebral levels of 5-HT, although its rate of synthesis was inhibited at the lowest dose. The variations in the levels of 5-HIAA appears to be linked to its elimination from the brain. The higher doses cause increases in NA levels and turnover rates.

Animals↗
PubMed1984

[Effect of ethanol in the pre-ovulatory period on the ovarian cycle, progesterone and estradiol in the rat].

The effect of high doses of ethanol (2 and 4 g/kg) administered to rats in pre-ovulatory periods (18th hour of diestrus) was studied. Plasma levels of estradiol and progesterone were measured at 10 hours of oestrus and changes in the ovarian cycle and the number of mature follicles were recorded. Compared with the control group, the receptive phase of estrus of the treated animals was longer lasting over 2 to 3 days. There was also an increase in the number of mature follicles as well as an increase in the plasma level of estradiol on the morning of estrus. Progesterone values showed no significant variations. Ethanol administered at the 18th hour of diestrus inhibits ovulation but not follicle development and allows the maintenance of high levels of estrogens on the morning of estrus. As a result the keratinization of the vaginal epithelium and the estrus phase are prolonged by 2 or 3 days.

Animals↗
PubMed1983

Influence of dimethylsulphoxide on the functional state of isolated rat hepatocytes.

The effect of dimethylsulphoxide upon respiration, glycolysis and gluconeogenesis in isolated rat hepatocytes was studied. The results show that the glycolysis pathway is strongly inhibited by the action of dimethylsulphoxide in the hepatocytes, with increased glucose uptake and reduced net flux. However, the alterations in respiration and the gluconeogenesis pathway are less pronounced, the only significant change being an increase in respiratory activity during the first 10 min of incubation with dimethylsulphoxide.

Animals↗
PubMed1980

[Effect of gamma-hexachlorocyclohexane (Lindane) on the brain and serum tryptophan (author's transl)].

The effect of convulsant doses of gamma-hexachlorocyclohexane (Lindane) on the brain and serum tryptophan contents as well as on the serum FFA contents was studied. The results indicate a possible correlation between the fluctuations in the FFA, free serum and brain tryptophan concentrations. The total tryptophan concentrations increase as well as the brain tryptophan/free tryptophan ratio, with both experimental doses.

Animals↗