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Biomedical subjects

R Costa

Publications and source records attributed to R Costa.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Immunosuppressive drugs for the treatment of active myocarditis in children. Hemodynamic evaluation].

PURPOSE: To analyse hemodynamic parameters (left ventricles ejection fraction, cardiac index, mean pulmonary wedge pressure and left ventricle diastolic diameter, in a group of children with active myocarditis (diagnosed by endomyocardial biopsy) pre and post treatment with conventional therapy and immunosuppressive drugs (isolated prednisone or prednisone associated with azathioprine or cyclosporine). PATIENTS AND METHODS: Forty-four pediatric patients with active myocarditis were studied. Twenty males and 24 females from 10 months to 15 years old (median = 1.3 years). All patients were submitted to hemodynamic study and endomyocardial biopsy. The hemodynamic parameters mentioned above were analysed before and after the proposed therapy. The patients were distributed in group according to the admission in the protocol, group I (9 pts)--conventional therapy (CT); group II (12 pts)--CT plus prednisone; group III (16 pts)--CT plus prednisone plus azathioprine; group IV (13 pts)--CT plus prednisone plus cyclosporine. RESULTS: Forty-four patients were submitted to four different groups of therapeutic protocol. The hemodynamic parameters were analysed in each of them. Left ventricle ejection fraction were no significantly different in the pre and post therapeutic scheme in group I and II, they were significantly higher (p less than 0.05) in group III and IV. The same happened with cardiac index. The mean pulmonary wedge pressure no presented statistical differences in group I and II before and after treatment but significantly lower lends were observed in group III and IV. The same behavior were noted in the left ventricle end diastolic diameter. CONCLUSION: The association of azathioprine or cyclosporine to prednisone presented better results in the left ventricle function, when compared with conventional drugs or isolated use of prednisone, based in the analysis of same hemodynamic parameters.

Adolescent↗
PubMed1990

[Pacemaker with mechanical sensors. Accumulated experience in long-term follow-up].

PURPOSE: To evaluate the behavior of single chamber stimulation system, rate responsive with vibration sensing, taking into consideration the results of long term clinical follow-up. PATIENTS AND METHODS: From september 1986 to april 1989, 70 patients received pacemakers with vibration sensing. Sixty four patients (91.9%) implanted Activitrax I model and six (8.1%) Activitrax II. Thirty-one (44.3%) were men and the mean age was 51.2 years. Fifty-one patients (72.9%) had complete atrioventricular block, 11 (15.7%) sinus node dysfunction, one (1.4%) sinus node and atrioventricular disease, and one (1.4%) for therapeutic support of arrhythmia. The etiology of these dysfunctions were Chagas' disease in 31.4%, myocardiosclerosis in 35.7%, post-operative in 15.6%, post-av node fulguration in 5.8% and idiopathic in 11.5%. The group was submitted to clinic and electronic evaluation and laboratory examinations: echocardiogram, dynamic ECG, stress test and ergoespirometric test. The mean follow-up as 19.6 months. RESULTS: Clinic evaluations: decrease in congestive heart failure functional class in 86% of the patients. No recurrence of syncopes and no cardiac deaths. Echocardiogram: increase in ejection fraction in 42% of patients. Dynamic ECG: appropriate rate response in 94.3% of patients (good cronotropic response). Ergoespirometry: increase in oxygen consumption in 75% of studied cases, Electronic evaluation: absence of generator dysfunction; complications in 18% of cases, all corrected by reprogramation. CONCLUSION: The single chamber cardiac stimulation system with vibration sensing showed safety, efficacy and low rate of complications.

Adolescent↗
PubMed1989

[On the eventual psychotropic, cardiovascular and aphrodisiac properties of yohimbine, an old drug with new indications].

The authors examined pharmacological actions of Yohimbine, an indolic alkaloid alpha-2-adrenoceptor antagonist. Several specific functions have been attributed to the alpha-2-adrenoceptor such as reduction of sympathetic outflow and pre-synaptic inhibition of noradrenergic neurons. Particularly the following are discussed: behavioural, antidepressant and anxiogenic effects: aphrodisiac effect; cardiovascular effects and metabolic effects.

Animals↗
PubMed1989

Pacing rate increase as cause of syncope in a patient with severe cardiomyopathy.

Hemodynamic deterioration occurs with ventricular pacing rate increase in the presence of severe chagasic cardiomyopathy. Syncope and orthopnea occurred during ventricular pacemaker evaluation when the pacing rate was temporarily increased by magnet application. Cardiac output decreased by 54%, the arterial blood pressure by 38%, and the pulmonary wedge pressure increased by 54%. Such severe myocardial compromise may limit the use of rate modulated pacemakers.

Cardiac Pacing, Artificial↗
PubMed1989

Abnormal dopamine sensitivity in some human prolactinomas.

In most of human prolactin (PRL)-secreting adenomas, dopamine and dopamine agonists normally suppress the excessive PRL secretion. Nevertheless, a subpopulation of such patients presents a relative insensitivity to the ergot derivative bromocriptine. Six patients with a macroadenoma (n = 5) or microadenoma (n = 1) were considered resistant to bromocriptine which, at a daily dose of 15-60 mg, did not normalize high plasma PRL levels. Culture studies of these adenoma cells showed that: (1) 10(-8) M bromocriptine produced a 32 +/- 16% inhibition of PRL release versus 65 +/- 12% obtained in the same conditions with normal human pituitary cells; (2) sulpiride (10(-6) M) reversed the inhibitory effects of bromocriptine, and (3) the bacterial endotoxins, cholera toxin (10(-11) M) and pertussis toxin (250 ng/ml), respectively, produced a 45-500% increase and a total abolition of bromocriptine-induced PRL inhibition. These observations and recent data of the literature allow to discuss the possibility of receptor or postreceptor defects in such tumors.

Bromocriptine↗
PubMed1989

Experience of a six-month treatment with sandostatin at increasing doses in acromegaly.

The French Sandostatin/Acromegaly Study Group performed a multicentric, prospective, open-label trial of incremental doses with the aim of obtaining the best antisecretory effect. Forty-two patients (24 women, 18 men) aged 22-71 years were involved, either after unsuccessful surgery and/or radiotherapy (30 patients), or as primary treatment (12 patients). Doses were increased from 3 x 100 to 3 x 500 micrograms/day, according to the results of hormonal investigations (GH profiles and Sm-C) performed each month and for each dose, and tolerability. Four patients dropped out because of major digestive troubles. Recurrent pain at the injection site and minor gastrointestinal disorders were noted in some patients. Asymptomatic gallstones appeared in 4 patients. Carbohydrate tolerance and insulin secretion (determined by diurnal plasma glucose and insulin profiles) were not significantly altered by the various SMS doses. Clinical improvement was determined by the scoring of the symptoms. Mean plasma GH concentrations were significantly reduced for each SMS dose, compared to pretreatment values. Fifteen patients obtained 75% of GH values less than or equal to 2 micrograms/l. In 9 patients the highest dose failed to bring GH below 10 micrograms/l. Sm-C normalized in 17/31 patients. After 6 months of treatment a tumor reduction of 20-50% was found in 7 patients and greater than 50% in 5 patients. We conclude that (1) the tolerability of SMS is compatible with long-term treatments; (2) clinical improvement and biological criteria of efficacy are obtained in 3/4 acromegalic patients treated by SMS, and that (3) some patients are resistant to SMS and the increase in the dose does not improve the result.

Acromegaly↗
PubMed1989

[Sinus bradycardia in chronic neuroglycopenic syndrome. A case of "short intestine" syndrome].

The clinical pattern of the chronic hypoglycemic disorders is different from that of the acute disorders. While in acute hypoglycemic syndromes tachycardia usually occurs, in chronic hypoglycemic disorders there is, even if seldom, sinusal bradycardia. The bradycardia occurs after months with glycemia under 60 mg/dl and may be correlated to the neuroglycopenic state. It is easily reversible when plasma glucose concentration approaches the normal range again. Recently we observed sinusal bradycardia set up during the chronic hypoglycemia state, lasting from more than 5 months, in a man submitted to subtotal intestinal resection, owing to wide extensive eosinophilic granuloma. The bradycardia disappeared quickly after the correction of the hypoglycemia, when the patient was submitted to parenteral hyperalimentation with a silicone rubber catheter in the superior vena cava. We suggest to set the bradycardia among the markers of undernutritional syndromes beside the known anthropometric, biochemical and immunological signs.

Adult↗
PubMed1989

Growth of bone marrow CFU-GM in a case of cyclical neutropenia. Preliminary report.

We studied bone marrow CFU-GM growth behaviour of a 9-year-old male child with cyclic neutropenia. The cultures were performed on day 0 and on day 13 of cyclic oscillation, in order to study some correspondences between CFU-GM culture parameters and the phases of a whole cyclic oscillation "in vivo". We explored the CFU-GM growth under three different conditions of GM-CSA production: a) standard source of CSA; b) endogenous GM-CSA assay; c) GM-CSA-gamma-globulin assay. At both observation times the endogenous GM-CSA assay produced more aggregates than the baseline culture. The GM-CSA-gamma-globulin assay partly corrected the growth increase, produced by endogenous assay. At time 0, at the nadir of peripheral blood neutrophils, there was a balance between the number of aggregates, appeared early in culture and early degenerated, and those appeared late. From progenitor cells culture performed on day 13 of cycle, a week before the zenith of neutrophils in vivo, we obtained an increase in aggregates, which appeared late. The values of CFU-GM grown from the culture performed on day 13 reached higher levels than the ones performed on day 0. The CFU-GM growth behaviour shows that in our case with cyclic neutropenia there is no defect in progenitor cells, while on the contrary there is an increase in CSA production.

Agranulocytosis↗
PubMed1989

[The biopsy in the diagnosis of pericardial involvement by malignant tumor].

We performed pericardial biopsy by subxiphoid approach in twelve patients (eight men, four women) with cardiac tamponade or pericardial effusion without low cardiac output, in order to search for the underlying disease. Five patients (41%) had pericardial biopsy with malignant neoplastic invasion. In seven patients (59%) the biopsy was nonspecific; in these patients, the diagnosis was made by another methods. We concluded that the pericardial biopsy is a safe method, with high especificity but low sensibility in the diagnosis of malignant pericardial invasion.

Biopsy↗
PubMed1989

Pharmacokinetics and bioavailability of oral acetylcysteine in healthy volunteers.

The plasma pharmacokinetics of oral acetylcysteine(N-acetylcysteine, NAC) after the administration of single 600 mg and repeated 200 mg doses and the relative bioavailability of the two regimens were studied in 12 adult subjects. On two different occasions in a cross-over, balanced fashion the subjects were administered orally either a single dose of NAC 600 mg as effervescent tablets or 4 repeated doses of NAC as granules in sachets at the regimen of 200 mg t.i.d. Venous blood samples were obtained just before dosing and 20, 40 min, 1, 1.5, 2, 3, 4, 6, 8, 10 and 12 h after the administration of NAC 600 mg; with the 1st, the 2nd and the 4th doses of NAC 200 mg samples were taken just before dosing and after 20, 40 min, 1, 1.5, 2, 3, 4, 6 and 8 h, the last sampling after the 1st dose being the one before the 2nd dose. A detailed description of the assaying methods of NAC is given in the text. As indexes of bioavailability Cmax' tmax and AUC of NAC plasma concentrations were considered and MRT was taken as an estimate of its persistence in plasma. NAC was quickly absorbed without any significant difference in tmax among the doses. With the 600 mg dose Cmax' AUC and MRT were greater than with a single 200 mg dose; after summing up the values of these parameters for the 200 mg doses no significant differences were observed in comparison to the single 600 mg dose in Cmax and AUC, while MRT resulted significantly higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcysteine↗
PubMed1988

Nitrilotriacetic acid (NTA) induces aneuploidy in Drosophila and mouse germ-line cells.

The ability of nitrilotriacetic acid (NTA) to induce aneuploidy was studied in the germ line of both Drosophila and the mouse. The Free Inverted X Chromosomes (FIX) genetic system, adopting a brooding scheme, was used to detect induced aneuploidy in Drosophila, and a cytogenetic method based on chromosomal counting in secondary spermatocytes was used in the mouse. In Drosophila a highly significant (P less than 0.001) increase of aneuploidies was produced by NTA (5 x 10(-2) M), which was greater than that produced by colchicine (7.5 x 10(-6) M) and 5-fluorodeoxyuridine (10(-4) M), which were used as positive controls. Brooding effects were observed with NTA, which produced a maximum induction of chromosomal gain in brood I, suggesting a possible stage-specific action during meiosis. The ability of NTA (275 mg/kg body weight) to induce meiotic aneuploidy (hyperhaploidy) also was confirmed in the mouse (P less than 0.001), where all the aneuploidies detected were attributable to treatment of the metaphase I stage.

Acetates↗
PubMed1988

Mutagenicity of lead chromate in Drosophila melanogaster in the presence of nitrilotriacetic acid (NTA).

By using the sex-linked recessive lethal mutation test in Drosophila melanogaster (standard Basc scheme) we analysed the mutagenic effects of treatments by feeding with nitrilotriacetic acid (NTA: 5 X 10(-2) M), with the insoluble Cr(VI) compound lead chromate, PbCrO4 (supernatant of 4.6 X 10(-4)-M suspension in which the actual concentration was 0.06 gamma/ml as Cr(VI)) and with both compounds preincubated at 3 relative ratios (NTA: 5 X 10(-2) M; PbCrO4: 4.6 X 10(-4), 4.6 X 10(-5) and 9.2 X 10(-6) M, respectively). The estimation of mutation frequencies was done at different developmental stages of the germ cells, namely spermatozoa, spermatids and spermatocytes. Ethyl methanesulphonate (EMS: 5 X 10(-3) M) was used as the reference positive control, with clearly mutagenic results. Treatments with NTA or with PbCrO4 alone did not induce any significant increase of the mutation frequency. PbCrO4 at the 3 concentrations tested was completely soluble in the 5 X 10(-2)-M NTA solution, and the mixture of NTA and PbCrO4 induced significant increases of the frequency of sex-linked lethal mutations, with a significant dose-effect relationship with respect to PbCrO4, apparently as a result of the interaction of the compounds and subsequent release of the genotoxic heavy-metal Cr(VI) ions. This result indicates an important synergistic action of NTA with PbCrO4 under the conditions described.

Acetates↗
PubMed1988

Pseudomelanosis of the duodenum. Endoscopic, histologic, and ultrastructural study of a case.

We present the endoscopic, microscopic, and histochemical studies of a patient with pseudomelanosis of the duodenum. The pigment was located mainly in the lysosomes of macrophages in the lamina propria and was heterogeneous, showing features of melanin, pseudomelanin, and hemosiderin. The origin of this pigment remains unknown, but antihypertensive medication may have played a role.

Aged↗
PubMed1988

Histological and immunohistochemical features in chronic delta hepatitis.

Forty-six liver biopsies from HBsAg Delta/anti-Delta serum positive patients with chronic hepatitis were compared with liver specimens from HBsAg positive Delta/antiDelta negative patients. The results indicate more severe histologic damage and inflammation among subjects who are serum-positive to the Delta system. Specific virus antigen was found in liver cell nuclei of almost all the Delta IR patients (93.5%). The rate of diffusion was directly proportional to the severity of histological lesions, which is in linea with the direct cytopathic effect of the Delta virus as ascertained in various other studies.

Biopsy↗
PubMed1987

[Effect of polyunsaturated phosphatidylcholine and vitamin B complex on the metabolism of selenium homotaurocholic acid in patients with chronic liver disease].

SeHCAT, a synthetic homologue of thaurocolic acid, may be used to examine the dynamics of enterohepatic circulation. A greater retention of SeHCAT may be attributed to a defective hepatic clearance and to a partial redistribution of the biliary acid pool outside the enterohepatic circle. This method has been applied to 20 patients affected with chronic hepatic disorders. The percentage of retention of SeHCAT in normal subjects was 19-20 on average. The hepatopathic patient has an average SeHCAT retention of 54%. After treatment with polyunsaturated phosphatidylcholine (EPL) plus vitamin B complex i.v., the percentage of SeHCAT retention was significantly less than 31% (P less than 0.001). It can be hypothesized that the drug determines an improvement of the enterohepatic circle (acting on the hepatic clearance) in patients with chronic hepatic disorders as shown by the reduction of the percentage of SeHCAT retention noticed.

Adult↗
PubMed1987

Body composition in adolescents: estimation by total body electrical conductivity.

This comparative study, conducted on 28 boys and girls of widely varying fatness, was designed to validate a new whole-body composition method [total body electrical conductivity (TOBEC)], based on bioelectrical properties of the human body. A significant correlation [r = 0.911; standard error of the estimate (SEE) = 5.3 kg] was demonstrated between the transformed TOBEC scores (TOBEC0.5 X Ht) and lean body mass (LBM) determined by hydrodensitometry and corrected for individual variations in hydration (LBMd + W). TOBEC determinations also correlated well with 1) total body water determined by deuterium oxide dilution (r = 0.877; SEE = 4.5 liters), 2) total body potassium determined by means of a 4 pi whole-body counter (r = 0.860; SEE = 430.7 meq), 3) LBM derived from skinfold thicknesses (r = 0.850; SEE = 5.8 kg). The residuals of the regression between LBMd + W and TOBEC scores did not show any significant correlation with either the potassium or the water content of the LBM. The results indicate that TOBEC is a simple, rapid, reliable, and noninvasive technique for delineating changes in body composition that occur in children during growth.

Adolescent↗