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Biomedical subjects

C Gomes

Publications and source records attributed to C Gomes.

46 records · Page 3Linked to original sources

Interaction of alpha- and beta-adrenergic receptor blocking agents: circulatory effects in the conscious rat.

The alpha-receptor blockers phenoxybenzamine and phentolamine produced similar circulatory effects, e.g. hypotension and tachycardia in the conscious rat. The hypotension was more pronounced than that seen after an acute cervical transection of the spinal cord or after hexamethonium treatment. The tachycardia was blocked by drugs with beta 1-receptor blocking capacity while the hypotensive response was blocked by drugs with beta 2-receptor blocking capacity. The pronounced hypotension and tachycardia was absent after spinal transection, hexamethonium pretreatment or adrenal demedullation. In adrenal demedullated rats substitution with adrenaline after alpha-receptor blockade produced tachycardia and hypotension of the same degree as seen in intact rats after alpha-receptor blockade. There was no correlation between the degree of beta-blocker induced decrease in heart frequency and increase in blood pressure after alpha-receptor blockade, while a significant correlation was found between the alpha-blocker induced decrease in blood pressure and the subsequent beta 2-blocker induced increase in blood pressure. In spinal rats, pretreated with phentolamine, adrenaline caused a depressor response. This depressor response was converted into a pressor response by administration of beta-blockers at doses which seemed to correlate well with the doses of beta-blockers needed to effectively block the alpha-blocker induced hypotension in intact animals. It is concluded that acute administration of phentolamine or phenoxybenzamine, by blocking alpha-receptors causes a reflex increase in adrenaline output, which subsequently further decreases the blood pressure and increases the heart frequency by stimulation of beta-receptors.

Adrenergic alpha-Antagonists↗

Hepatic amebiasis-analysis of 56 cases. II. Laboratory and chest x-ray findings.

Laboratory and chest x-ray findings in 56 cases of hepatic amebiasis previously reported are described. Anemia and an elevated E.S.R., frequently without an elevated leucocyte count, were the most frequent hematologic findings. Abnormalities of liver function tests were mild and nonspecific. The most frequent abnormalities seen in chest x-ray were an elevated right hemidiaphragm whose motility on fluoroscopy was reduced or abolished. The abnormalities may be of great help in diagnosis in endemic areas were more sophisticated facilities may not be available.

Alanine Transaminase↗

Hepatic amebiasis, analysis of 56 cases. I. Clinical findings.

The clinical findings in 56 patients with hepatic amebiasis are reviewed. This illness was most frequent in male black patients, 20-39 years old. The clinical picture is dominated by upper right quadrant abdominal pain, general malaise, pain on percussion of the right hypochondrium and tender hepatomegaly. Jaundice is not rare and appears to have no prognostic significance. The importance of early diagnosis is emphasized.

Adolescent↗

Effects of morphine on central catecholamine turnover, blood pressure and heart rate in the rat.

In the unanaesthetized rat morphine caused increased dopamine (DA) turnover, unchanged or possibly increased central noradrenaline (NA) turnover (utilization), hypertension and tachycardia. In the anaesthetized rat, brain DA turnover was not affected, whereas the NA-turnover was decelerated, particularly in some brain regions, e.g. cerebral cortex and medulla oblongata, and hypotension and bradycardia was obtained. Both biochemical and cardiovascular effects of morphine were antagonized by naloxone. A very small dose of morphine (1 mg/kg) caused tachycardia also in the anaesthetized rat. Decerebration just inferior to the inferior colliculus abolished the conscious rat, but left the circulatory, depressant actions of the drug unchanged. The morphine-induced cardiovascular effects, particularly the hypotension and bradycardia in the anaesthetized animal, are suggested to be related to, or mediated by, the effects of the drug on brain NA-mechanisms, especially in view of several similarities between morphine and the antihypertensive alpha-adrenergic agonist clonidine. Whereas higher brain structures appear important in the excitatory, circulatory effects of morphine, structures below the decerebration level, e.g. medulla oblongata, appear primarily involved in the hypotension and bradycardia obtained in the anaesthetized animal. Possibly, morphine has a diphasic dose-response curve with respect to cardiovascular function and, by inference, on brain noradrenergic mechanisms.

Animals↗

Evidence for involvement of central noradrenergic neurons in the cardiovascular depression induced by morphine in the rat.

Morphine caused in the anaesthetized rat reduction in brain noradrenaline (NA) turnover, hypotension and bradycardia, similarly to the antihypertensive, alpha-adrenergic agonist, clonidine. All effects of morphine were antagonized by naloxone, as well as the alpha-receptor antagonist, yohimbine. In contrast, naloxone did not affect the circulatory depression and reduction in brain NA utilization by clonidine which both previously have been found to be antagonized by yohimbine. In contrast to clonidine, morphine even in high doses did not facilitate the flexor reflex activity of acutely spinalized rats. Pretreatment with protriptylin largely attenuated the circulatory depressive effects of morphine, as it has previously been found to block the corresponding effects of clonidine. Thus, the morphine-induced cardiovascular depressive effects are primarily elicited by activation of opiate receptors. However, the inhibition of brain NA neurotransmission by morphine appears critically involved in the mediation of the circulatory depression.

Adrenergic Fibers↗

Gammahydroxy butyric acid: cardiovascular effects in the rat.

Gammahydroxybutyric acid (GHBA) 1 g/kg i.p. induced a marked and sustained increase in heart frequency and blood pressure in the rats. These effects of GHBA were abolished by a high spinal transection. In biochemical experiments GHBA in the same dose increased the turnover of brain noradrenaline but decreased the turnover of dopamine. The cardiovascular effects of GHBA are suggested to be of central origin, and possibly involve central noradrenergic mechanisms.

Animals↗

[Energy balance in infants born from HIV seropositive mothers]

OBJECTIVES: A nutritional evaluation of infants born from HIV seropositive mothers was carried out during their follow up and diagnostic investigation. The energy balance (EB) of infected and noninfected children were compared. METHODS: The energy balance (intake energy, fecal energy, and resting energy expenditure) was prospectively determined by indirect calorimetry, considering 13 infants (6 girls and 7 boys) between 1 and 6 months of age, born from HIV positive mothers. This was made in two opportunities: before and after the diagnosis of the disease. A full nutritional assessment, including clinical examination and anthropometric measures (weight, height and skinfold thickness), was also determined in these two opportunities. After the definite diagnosis, the infants were finally assembled in 2 different groups: infected (5 in 13) and noninfected (8 in 13). The children were monthly submitted to clinical evaluations and orientation, during all the study. RESULTS: By analyzing the anthropometric measures of the two groups, it was observed that the infected group had malnutritional manifestations since the first evaluation. The resting energy expenditure (kcal/kg/dia) of the infected group was higher than that of the noninfected group: 64.5-/+16.8 vs 48.0-/+5.7 (p<0.05) at the first evaluation and 68.0-/+11.7 vs 51.8-/+3.1 (p<0.05) at the second, respectively. CONCLUSION: The higher resting energy expenditure of the children in the infected group might be the cause of the protein energy malnutrition during the asymptomatic phase when the diagnosis was uncertain.

Journal Article↗

[Predictive factors of hospital and 6-month morbidity and mortality in hospitalized elderly patients].

This article presents the results of a prospective multivariable study of elderly patients aged over 70 years, hospitalized in an Internal Medicine Department of a Central Lisbon Hospital. The study aimed to identify, at the beginning of hospital admission (HA), predictive factors of hospital mortality (HM) and mortality at 6 months, of duration of HA, of admission to a nursing home at the time of discharge and during a period of 6 months thereafter and of hospital readmission during the 6 months following discharge. The study included 158 patients with a mean hospital stay of 15 days and a hospital mortality of 12%. The main pathologies responsible for hospital admission were cerebrovascular accident (22%), heart failure (20%) and pneumonia (16%). Mortality at 6 months was 29% and hospital readmission in the 6 months thereafter was 24%. When the patient was cared for by the spouse there was a statistically significant correlation with a shorter duration of admission (p = 0.006). Mean hospital stay was not significantly associated with any other variable. A subjective medical evaluation (SME) at the start of HA (p = 0.001), a low Barthel score prior to and at the time of HA, low serum albumin (p = 0.001) and a high leucocyte count (p = 0.005) were correlated with a higher HM. Nursing home admission was only positively correlated with cerebrovascular pathology. Mortality at 6 months was significantly correlated with the SME (p = 0.001), a low Barthel score prior to admission (p < 0.008) and at the time of HA (p < 0.001), nursing home residency (p < 0.005) and a low mental test score (p < 0.01). Hospital readmission at 6 months was influenced by the SME (p < 0.04) and by the reduction in the Barthel score caused by the illness and HA (p = 0.004). These correlations enabled the development of mathematical models that predict HM and mortality at 6 months and admission to a nursing home at the time of discharge and during a period of 6 months thereafter. They could be important in identifying elderly patients' needs early in the hospital admission and in the improvement of the strategy necessary for a successful and dignified hospital discharge.

Aged↗