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J Segovia

Publications and source records attributed to J Segovia.

88 records · Page 5Linked to original sources
PubMed1987

Changes in the activity of GAD in the basal ganglia of the rat after striatal dopaminergic denervation.

The aim of this experiment was to study the effect of a unilateral lesion of the dopamine-containing nigro-striatal pathway, on the activity of glutamic acid decarboxilase (GAD) in different structures at two survival times: 4 and 8 weeks. The structures studied were the striatum and its output target areas, globus pallidus, entopeduncular nucleus and substantia nigra. Four weeks after the lesion, GAD activity was increased in the ipsilateral striatum, globus pallidus and substantia nigra. This effect was reversed at 8 weeks, when a decrease in enzyme activity was observed. These time related changes in enzyme activity reveal the presence of a physiological compensatory process.

Animals↗
PubMed1986

gamma-Aminobutyric acid release in the globus pallidus in vivo after a 6-hydroxydopamine lesion in the substantia nigra of the rat.

This experiment was designed to determine whether the release of gamma-aminobutyric acid (GABA) in the globus pallidus (GP) is affected by a lesion of the nigrostriatal pathway. Rats were lesioned with 6-hydroxydopamine 4 weeks prior to study of the in vivo release of GABA. A microdialysis probe was stereotaxically implanted in halothane-anesthetized animals in a vertical position on both GPs. The perfusates were analyzed for their GABA content with a high performance liquid chromatography technique. Compared to unlesioned controls, a marked decrease in the overflow of GABA was observed in the GP contralateral to the lesion, whereas the ipsilateral GP showed a slight increase. The differences between the sides were exaggerated after KCl (100 mmol) administration. The results are discussed in terms of a possible bilateral influence of dopamine terminals in the striatum on GABA transmission.

Animals↗
PubMed1986

Extracellular levels of amino acids in striatum and globus pallidus of 6-hydroxydopamine-lesioned rats measured with microdialysis.

Extracellular aspartate, glutamate, glutamine, taurine and GABA concentrations were measured by microdialysis in the rat striatum and globus pallidus after a unilateral 6-hydroxydopamine lesion of the dopamine system. The basal and potassium-evoked overflow of GABA was increased in the ipsilateral striatum, but the evoked overflow was decreased in both contralateral striatum and pallidum. Both basal and evoked overflow of glutamate was increased in ipsilateral striatum. The basal overflow of aspartate was significantly increased in the ipsilateral side. Basal glutamine on the other hand was decreased in the ipsilateral side. Taurine remained unchanged in both regions. These results suggest that dopamine is involved in the regulation of transmission by GABA and glutamate. Since glutamine might be the precursor to glutamate, the change in glutamate might affect the glutamine level. The changed aspartate level has no obvious explanation.

Amino Acids↗
PubMed1979

Institutional outpatient clinics: a case study in unmet needs.

An outpatient clinic of a charity hospital, managed by a medical school of a large Latin American country, was studied to assess the characteristics of the patients and the management of their conditions. All medical records of registered patients of the clinic were abstracted for identification, demographic and clinical data, for two periods of one month each, yielding 2,153 patient observations. The study period represented 18 per cent of the total days of operation of the clinic in 1975. A 20 per cent stratified sample of all cases was studied in depth to characterize the management of patients. Up to 40 per cent of all patients were rejected by the clinic, a result of the system of selection and handling of the patients. Only 36 per cent of all patients received minimally satisfactory care when treated. These results are analyzed within the framework of the conflict between professional and academic values of the medical profession and the medical and social needs of the patients.

Appointments and Schedules↗
PubMed1977

Protein distribution is submitochondrial particles after lipid peroxidation.

Three fractions of submitochondrial particles were isolated by differential centrifugation of mitochondrial inner membranes incubated with 1 mM ascorbate. Proteins were separated by polyacrylamide gel electrophoresis and their pattern was found to be different for the three fractions. These results are in agreement with previous work which showed the dissimilar enzyme distribution and chemical composition of these submitochondrial particles and pointed out the heterogeneity of the inner mitochondrial membrane.

Animals↗
PubMedDate not supplied

Newfoundland Panel on Health and Medical Care--adult health survey.

An adult health survey was undertaken on the island portion of the Province of Newfoundland as part of the Newfoundland Panel on Health and Medical Care. This study aims to develop models of medical care utilization over a seven-year period, before and after a major restructuring of the provincial health care system. A health survey on a large sample (11,789 individuals) permits both descriptive and explanatory analysis at the regional level. The results of the survey are presented first in a descriptive format, as they were included in reports for policy makers and managers, using administrative aggregations. To study regional differences, descriptive and multivariate analyses were done on an aggregation by an urban dimension, which divides the island into three areas. As expected, there were major differences across regions, and complex interactions on selected variables. The usefulness of health surveys for planning and evaluation of health reform is discussed.

Adult↗
PubMedDate not supplied

The association between self-assessed health status and individual health practices.

We report the association between single health practices and self-assessed health status. Data were collected by telephone survey applied to all adults in a sample of households in metropolitan St. John's; questionnaires were completed for 3,300 subjects. Five health practices--smoking, exercise, sleep, weight and drinking--as defined by previous studies were compared with self-assessed health status--good or poor--using logistic regression; linear and quadratic functions were fitted, plots were prepared and the direction and strength of the associations studied using odds and odds ratios. For sleep, smoking, weight and exercise, our results confirm the definitions used in previous studies. Current non-drinkers in our sample do not report good health as frequently as moderate drinkers. Breakfast--which was analyzed by conventional cross-tabulation--showed no association with health status.

Adult↗
PubMedDate not supplied

Rhodococcus equi: first case in a heart transplant recipient.

Rhodococcus equi is a gram-positive diphtheroid that occasionally affects immunocompromised patients, usually causing a chronic respiratory infection with cavitating pulmonary opacities on chest radiograph that resemble mycobacterial or fungal disease. Etiologic diagnosis presents a number of pitfalls, because Rhodococcus equi isolates mimic many of the characteristics of other microorganisms more familiar to the laboratory staff. The treatment of choice for this disease has not yet been established, and its mortality rate is greater than 50% in individuals with human immunodeficiency virus and 20% to 25% among the remaining patients. We describe here the first case of Rhodococcus equi infection in a heart transplant recipient. Clinical presentation was typical, and treatment with a sensitivity-based combination of antibiotics resulted in resolution of both the clinical and radiologic picture.

Adult↗
PubMedDate not supplied

Heart transplantation for cardiac angiosarcoma: should its indication be questioned?

Two men, aged 31 and 32 years, respectively, underwent orthotopic heart transplantation, in both cases to treat primary cardiac angiosarcoma of the right atrium. Total removal of the tumor was performed, and no evidence was found of distant dissemination at the time of surgery. Their postoperative progress was good; however, the patients died 8 and 9 months after transplantation, respectively, of multiple brain metastases. We do not consider heart transplantation to be indicated in the management of malignant cardiac tumors.

Adult↗
PubMedDate not supplied

Heart transplantation in a patient with liver hydatidosis.

The human can serve as an accidental intermediate host to Echinococcus granulosus, a parasite that targets dogs as its definitive hosts. We present the case of a 27-year-old man with liver hydatidosis, who underwent heart transplantation because of ischemic cardiomyopathy. The immunosuppressor treatment had no effect on the size of the cysts, which were removed surgically 14 months after heart transplantation; good results persist after 3 years of follow-up.

Adult↗