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Biomedical subjects

A M Costa

Publications and source records attributed to A M Costa.

At least 55 records · Page 3Linked to original sources
PubMed1993

[High-resolution electrocardiography in arrhythmogenic right ventricular disease].

PURPOSE: To determine the value of the high-resolution ECG for the differential diagnosis of arrhythmogenic right ventricular disease. METHODS: A group of 33 patients were studied, 16 males, mean age 34 +/- 16 years. All patients presented non-sustained or sustained or repetitive monomorphic ventricular tachycardias, with left bundle branch block morphology. The anatomic and functional evaluation of the right ventricle was made by a previous echocardiogram. No patient presented left ventricular or septal pathology. High-resolution ECG were obtained from a Corazonix-Predictor II program. In the filtered QRS was analyzed root mean square of the last 40ms QRS, the final lasting of the low amplitude signals < 40 microV and filtered QRS duration. Ten patients underwent to electrophysiological study with right ventricular mapping. RESULTS: The ventricular tachycardias was non-sustained in 18 patients, sustained in 8 and repetitive monomorphic in 7 patients. The echocardiogram was normal in 23 patients, and all these also presented normal high resolution ECG. Among the 10 patients with altered echocardiogram, 9 presented abnormal high-resolution ECG (sensibility 90%; specificity 100%; positive predictive value 100%; negative predictive value 96%; efficacy of the method to define the presence of manifested right ventricular pathology was 96%). Among the 10 patients with altered echocardiogram, 8 underwent to electrophysiological study. In all was detected an abnormal ventricular mapping and abnormal high-resolution ECG. CONCLUSION: The high-resolution ECG is an useful method to define a right ventricular manifested pathology in presence of arrhythmogenic disease of this cavity.

Adolescent↗
PubMed1985

[Potentials and limitations of viscometry in hemorheological studies].

The problems of viscometric studies are discussed in depth on the basis of the most recent advances in hemorheology. We present here our contribution to the solution of numerous methodological problems. Particular emphasis was set on the problem of optimization and standardization of viscometric techniques for the study of erythrocyte deformation and aggregation.

Blood Viscosity↗
PubMed1975

An electron microscope study of Darier's disease.

An electron microscope investigation was performed on cutaneous biopsies from four patients with Darier's disease. Suprabasal lacunae with acantholytic cells a prominent feature. Basal cells and acantholytic cells showed an increase in tonofilaments. Corps ronds appeared as vacuolated cells.

Acantholysis↗
PubMedDate not supplied

Inhibition of M-current in cultured rat superior cervical ganglia by linopirdine: mechanism of action studies.

The mechanism involved in the blockade of M-current by linopirdine was studied in cultured rat superior cervical sympathetic ganglia using whole-cell patch clamp recording. The effects of modulators of intracellular signal transduction pathways on muscarine- or linopirdine-induced inhibition of M-current were compared. Intracellular addition of GDP-beta-S (500 microM) attenuated M-current block by muscarine (1 microM) but not that of linopirdine (10 microM). Intracellular dialysis of GTP-gamma)-S (100 microM) enhanced and prolonged muscarine-induced inhibition of M-current but had no effect on the activity of linopirdine. Intracellular BAPTA (20 mM) also inhibited the effects of muscarine without affecting those of linopirdine. Intracellular application of linopirdine had no effect on either basal M-current amplitude or the ability of linopirdine to block M-current when administered extracellularly. These results indicate that M-current inhibition by linopirdine is unlikely to be either G-protein-mediated or calcium-mediated or to involve an intracellular site of action and are, therefore, consistent with a direct block of the M-channel from its extracellular side.

Animals↗
PubMedDate not supplied

Enterovirus 71 infection and acute neurological disease among children in Brazil (1988-1990).

Surveillance for Enterovirus 71 (EV-71) infection in children up to 15 years of age was carried out in Brazil, from 1988 to 1990. Patients with acute neurological diseases (AND) such as flaccid paralysis, Bell's palsy, acute cerebellar ataxia and Guillain-Barré syndrome were included in the study. EV-71 infection was detected in 24 of 426 children (5.6%) with AND. EV-71 infection was confirmed only by virus isolation in 13 children, by virus isolation and seroconversion in 4, and by seroconversion alone in 7. EV-71 was also isolated from 15 of the 427 household contacts (3.5%) of 165 AND patients. There was some evidence of high infectivity of EV-71: household clusters were detected in the case of 7 of 24 children (29.1%) infected with EV-71 and manifesting AND; EV-71 was isolated from 11/40 household contacts (27.5%) of the infected patients but from only 4/387 household contacts (1.0%) of children in whom it was not possible to demonstrate EV-71 infection. Seven of the 24 children infected with EV-71 exhibited residual motor deficiency when examined 6 months after the disease onset. The relevance of these results for the Plan for Global Eradication of Wild Poliovirus is discussed, as well as the need to increase knowledge about the behaviour of this virus and its possible association with AND.

Acute Disease↗
PubMedDate not supplied

Necrobiotic xanthogranuloma without periorbital involvement: an ultrastructural investigation.

A case of necrobiotic xanthogranuloma without typical periorbital involvement is described at the ultrastructural level. The patient, a 58-year-old Italian man, presented in 1995 with a brief history of nodulo-papular lesions commencing on the lower limbs, and mild paraproteinemia. During 6 years of follow-up, anemia, neutropenia with marked lymphopenia, and increased ESR were found, while serum cholesterol and triglyceride levels decreased from hyper to hypo values. Systemic diseases, such as diabetes, malignancy, or extracutaneous lesions, often associated with NXG, have not developed. Conventional histology was distinctive for NXG, and immunohistochemistry confirmed that dermal histiocytes were not of Langerhans cell lineage. At ultrastructure, regeneration and degeneration ("regen-degen") features were observed in some individual deep dermal histiocytes, which have not been previously documented in the literature. Identification of giant histiocytes showing 'regen-degen'' aspects might prove to be a useful ultrastructural diagnostic marker for NXG.

Cell Nucleus↗
PubMedDate not supplied

Concomitant radiotherapy with protracted 5-fluorouracil infusion in locally advanced carcinoma of the pancreas: a phase II study.

AIMS AND BACKGROUND: To evaluate the efficacy of combined radiation therapy and continuous infusion of 5-fluorouracil in patients with locally advanced carcinoma of the pancreas. METHODS: Between January 1992 and June 1999, 31 patients with locally advanced adenocarcinoma of the pancreas were treated in our Institute. In 20 patients, the tumor (65%) was located in the head of the pancreas and in 11 (35%) in the body or tail; 13 cases also showed involved nodes. Radiation therapy consisted in a median dose of 63 Gy in 33-36 fractions applied to the tumor and regional lymph nodes. Chemotherapy with 5-fluorouracil in continuous infusion, 250 mg/m2 daily, was administered in the first and fifth week of the radiation therapy. Thereafter, 22 patients received 3-10 cycles of adjuvant chemotherapy with same doses. Median follow-up of the series was 20 months. The toxicity of the treatment was scored according to WHO criteria. All patients underwent nutritional assessment at the time of radiochemotherapy. RESULTS: The median overall survival was 15.2 months (range, 4-42). At restaging, 17 cases (55%) showed no change and 14 (45%) a partial remission. At the end of radiochemotherapy in 8 (26%) of the cases there was indication for pancreatectomy, which was executed in 4 patients. At the time of the study, 2 patients (6.4%) were surgically proven disease free. Eleven of the 13 cases (85%) presenting involved nodes showed that the enlarged lymph nodes had disappeared. Nineteen patients (61%) are alive with clinical evidence of disease anti 2 cases are alive with liver metastases; 8 patients (26%) died for disease. In 74% of cases there was complete pain control. Tolerance to the regimen was good. Nutritional assistance was evaluated and was found to be correlated to survival. CONCLUSIONS: The results of the series confirm a good tolerance with low acute toxicity. Tumor down-staging and resectability rates were high, together with prolonged survival and a good quality of life.

Adenocarcinoma↗
PubMedDate not supplied

[Evolution of schistosomiasis endemicity in the Zona da Mata Sul, Pernambuco State, Brazil. Epidemiology and current situation: under control or out of control?].

In order to assess the present situation of schistosomiasis in the Zona da Mata Sul, Pernambuco State, Brazil, a study was conducted in the following phases: origin, historical and temporal evolution, and basic determinants of this health/disease process; critical assessment of comprehensive intervention programs implemented by the State in the region since 1970; and a case study in 17 counties, representing 1,424 communities and 485,200 inhabitants, and Brazil's second most endemic region based on prevalence rates for schistosomiasis. Temporal series over a 14-year period were used to analyze results of intervention programs. Conclusions were: a) current positivity rates are higher than those observed in the early 1980s; b) the programs' strategy focused almost exclusively on mass treatment, thus allowing for reinfestation and occurrence of new cases; c) proposals such as the PCDEN (Program for Control of Endemic Diseases in the Northeast) aimed at decentralization to the municipal level in the 1990s were not effectively implemented, helping to leave this persistent endemic out of control.

Brazil↗