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V P Teixeira

Publications and source records attributed to V P Teixeira.

16 recordsLinked to original sources
PubMed2001

Neuron count reevaluation in the myenteric plexus of chagasic megacolon after morphometric neuron analysis.

This study was made with the objective of reevaluating the colon denervation in chronic Chagas' disease. The diameters of neuron perikaryons of the myenteric plexus were measured on paraffin sections in a ring from the sigmoid in Chagas' disease patients, 17 with and 10 without megacolon and in 10 non-chagasic controls. All neurons were counted in ten en-echelon sections. Neuron hypertrophy only occurred in the group with megacolon, and the average increase in diameter was 69.3%. This could generate an error factor in the neuron count by increasing the probability of neurons being seen in a greater number of histological sections. The original result of the neuron count gave medians of 1264, 1961, and 2665 in the groups of chagasic patients with megacolon, without megacolon, and in the control, respectively. The denervation was greater than 55% in only seven megacolon cases (41.2%). After applying a correction factor, the median in the group with megacolon was 746, and the denervation was greater than 55% in 13 cases (76.5%). This occurrence demonstrates the need to apply a correction factor when the neuron count in chagasic megacolon is being evaluated and in the other pathologies where neuron hypertrophy may be found.

Adult↗
PubMed2001

Effects of ionizing radiation on progressive experimental renal disease: a hemodynamic approach.

In order to evaluate the progression of renal disease, Munich-Wistar rats were submitted to 5/6 nephrectomy and given whole-body x- or gamma-irradiation with or without remnant kidney protection or were submitted only to remnant kidney irradiation. All groups received a single 6-Gy dose immediately after surgery. Whole-kidney function, glomerular hemodynamics, 24-hour proteinuria and histopathology were assessed 60 days after surgery and irradiation. The irradiated nephrectomized animals presented whole-kidney function parameters comparable to those of normal rats. In addition, they were less hypertensive and had higher hematocrit. They showed glomerular hyperfiltration and hypertension even greater than their respective nephrectomized controls. However, the interrelations among the glomerular filtration determinants were somewhat different in irradiated animals. Their 24-hour proteinuria was significantly lower and the sclerosis index and tubulointerstitial injury score were markedly smaller. Among irradiated animals, the worst sclerosis index was observed in those with a shielded remnant kidney and the best in those without protection of the remnant kidney. This led us to speculate about a possible influence of resident mesangial cells on the early events following renal mass ablation and on the maintenance of subsequent physiopathologic changes. Therefore, radiation undoubtedly provoked a beneficial change in the course of renal disease when the renal mass ablation model was employed. Many factors could have contributed to this favorable feature including lower levels of systemic arterial pressure, less increment in DeltaP, diminished proteinuria, and maintenance of tubulointerstitial space integrity. Our data also suggest that development of glomerulosclerosis seems to be determined by events occurring immediately after injury.

Animals↗
PubMed1999

[Occurrence of encephalic and cardiac cysticercosis (Cysticercus cellulosae) in necropsy].

OBJECTIVE: To review the incidence and pathologic findings of cysticercosis diagnosed at autopsies, with emphasis on the most common organs affected. METHODS: Reports of 1.596 autopsies performed between 1974 and 1997 at a school hospital in Uberaba, MG, Brazil were studied. The following data were obtained: age, sex, ethnic group, body mass index, and the site of the cysticercosis. RESULTS: The study found diagnosis of cysticercosis in 53 autopsies (3.3%). The average age of patients with cysticercosis was 50 (range: 15 to 86 years); 62.3% were male, and 64.1% Caucasian. The most affected organs were: brain (79.2%), heart (22.6%), skeletal muscle (11.3%), and other organs (5.7%). No statistical differences were found comparing age, gender, ethnic group, and body mass index of the affected and the non-affected patients. In two cases of neurocysticercosis the lesions were located in the ventromedial nucleus of the hypothalamus. CONCLUSION: Both the overall incidence of cysticercosis and the incidence of cardiac cysticercosis were greater in the study than in other autopsy series from the same geographic areas. In two cases there was an association between hypothalamic cysticercosis and obesity

Adolescent↗
PubMed1999

Ocular linguatuliasis in Ecuador: case report and morphometric study of the larva of Linguatula serrata.

Linguatula serrata is a pentastomid, a cosmopolitan parasite belonging to the Phylum Pentastomida. Humans may act as an intermediate or accidental definitive host of this parasite, manifesting the nasopharyngeal or visceral form, with the latter having been described more frequently. The occurrence of ocular linguatuliasis is extremely rare, but it has been reported in the United States and Israel. The objective of the present paper was to report the first case of ocular linguatuliasis in Ecuador and to extend the morphologic study of L. serrata by morphometric analysis. The patient studied was a 34-year old woman from Guayaquil, Ecuador who complained of ocular pain with conjunctivitis and visual difficulties of two-months duration. Biomicroscopic examination revealed a mobile body in the anterior chamber of the eye. The mobile body was surgically removed. The specimen was fixed in alcohol, cleared using the technique of Loos, stained with acetic carmine, and mounted on balsam between a slide and a coverslip. It was observed with stereoscopic and common light microscopes in combination with an automatic system for image analysis and processing. The morphologic and morphometric characteristics corresponded to the third-instar larval form of L. serrata. To our knowledge, ocular linguatuliasis has not been previously described in South America, with this being the first report for Ecuador and South America. The present study shows that computer morphometry can adequately contribute both to the morphologic study and to the systematic classification of Pentastomids, and L. serrata in particular.

Adult↗
PubMed1998

Acute renal failure in experimental envenomation with Africanized bee venom.

Human victims of multiple bee or wasp stings have been reported and develop severe clinical signs and symptoms. Acute renal failure (ARF), usually due to acute tubular necrosis (ATN) was a frequent complication. The pathogenetic mechanisms of ATN occurring in these accidents are still unclear. In the present study, female Wistar rats weighing 150-200 g were injected intravenously with Africanized bee venom at a dose of 0.4 microL/100 g body weight, and the kidney was observed under light and transmission electron microscopy and in immunohistochemical studies. The animals were divided into two groups: an Early group studied 3 to 8 hours after inoculation, and a Late group studied 24 to 30 hours after inoculation. The animals showed ATN mainly in the cortex and outer medulla with cast formation. After 24 hours, frequent mitotic figures were found in the tubular epithelium. Immunohistochemical studies revealed the presence of myoglobin and muscle actin in the tubular casts. Under electron microscopy, proximal tubule segments showed increasing intracytoplasmic vacuoles and attenuation of the brush border and of the basolateral infolding. This segment and the thick ascending limb of Henle's loop showed hydropic degeneration. Dead cells with apoptosis or necrosis due to cellular disintegration resulted in tubular basement membrane denudation. In the Late group, figures of intracytoplasmic myelin could be observed, some of them containing mitochondrial fragments. These changes are likely to be due to interactive effects of venom components, mainly mellitin and enzymes such as phospholipases, both acting on biological membranes. The ATN found was probably due to multiple causes, mainly a direct action of the venom on tubular cells, myoglobinuria, and perhaps ischemic mechanisms.

Animals↗
PubMed1992

Enkephalin- and serotonin-like immunoreactivity in the aortico-pulmonary paraganglia of the white-belly opossum Didelphis albiventris (Marsupialia).

Serial histological sections of the interatrial septum and basal heart vessels of the weaned and juvenile white-belly opossum (Didelphis albiventris) were obtained in order to study the presence of paraganglia and their content of regulatory peptides and serotonin. Paraganglion groups were mapped between the aorta and pulmonary arteries and close to the bifurcation of the pulmonary trunk and were found to contain cells with immunoreactivity to serotonin and to the neuroendocrine markers PGP 9.5 and NSE. When these paraganglia were tested for immunoreactivity to a battery of regulatory peptides, all were found to be positive for methionine-enkephalin, leucine-enkephalin and galanin. The hypothesis is raised that these peptides and serotonin, besides catecholamines, produced by these paraganglia may play a physiological role in the functions of the cardiovascular system of the white-belly opossum.

Animals↗
PubMed1991

Immunocytochemical identification of neuroendocrine markers in human cardiac paraganglion-like structures.

Paraganglion-like structures (PLS) containing chromaffin-positive cells have been reported to be present in the adult human heart. The present work was initiated in order to evaluate the density of these structures in the interatrial septum and to study the presence of immunoreactivity of their cells to NSE and PGP 9,5 antibodies, two neuroendocrine markers. Six hundred 6-microns paraffin serial sections were obtained from the upper third of the interatrial septum from six adult human hearts. From 2 to 12 paraganglia were found in each case, and their principal cells stained positively with NSE and PGP 9,5 antibodies. Depending on how these PLS related to other cardiac structures, four different types were identified: Type I - "True paraganglia" (located adjacent to ganglia or nerve fibers); Type II - "Free paraganglia" (immersed in the interatrial adipose tissue, without evident connection to other structures); Type III - "Intraganglionic paraganglia" (located within the nervous ganglia); Type IV - "Intramyocardic paraganglia" (small nests of immunoreactive cells closely related to myocardiocyte bundles). These cardiac paraganglia, which probably belong to the visceral-autonomic group, may have a role in the regulation of the cardiac function and in the adaptive mechanisms of the heart. Its is also possible that they originate functioning and non-functioning tumours.

Adult↗
PubMedDate not supplied

[Contribution to the morphologic diagnosis of lung adiaspiromycosis].

The diagnosis of adiaspiromycosis is usually based on lung sections stained by hematoxylin-eosin, periodic acid Schiff and methenamine silver. Authors describe the fungus aspect examined by mucicarmin, picro-sirius and Congo red methods, including polarized light microscopy. In doubtful cases, these methods could contribute to histopathological diagnosis of Emmonsia parva var crescens.

Chrysosporium↗
PubMedDate not supplied

Pressure sores among malnourished necropsied adults--preliminary data.

UNLABELLED: Pressure sores are common among bedridden, elderly, or malnourished patients, and may occur in terminal ill patients because of impaired mobility, fecal or urinary incontinence, and decreased healing capacity. The aim of this study was to compare frequency of pressure sores between malnourished and non-malnourished necropsied adults. METHOD: All (n = 201) adults (age >/= 18 years) autopsied between 1986 and 1996 at the Teaching Hospital of Triangulo Mineiro Medical School (Uberaba) were eligible for the study. Gender, race, weight, height and main diagnoses were recorded. Ninety-six cases were excluded because of probable body water retention (congestive heart failure, hepatic insufficiency, nephrotic syndrome) or pressure sores secondary to peripheral vascular ischemia. Body mass index (BMI) was used to define malnourished (BMI < 18.5 kg/m2) and non-malnourished (BMI > 18.5kg/m2) groups. RESULTS: Except for weight (42.5kg; range: 28-57 vs. 60; 36-134.5kg) and BMI (16.9; range: 12.4-18.5 vs. 22.7; range: 18.5-54.6kg/m2), respectively, there were no statistical differences among 43 malnourished and 62 non-malnourished cases in relation to age (54.9 +/- 20.4 vs. 52.9 +/- 17.9 years), percentage of white persons (74.4 vs. 64.5%), male gender (76.7 vs. 69.3%) and main diagnoses. Five malnourished (11. 6%) and 7 (11.5%) non-malnourished cases had pressure sores (p=0.89). CONCLUSION: Pressure sores were equally common findings in necropsied persons with protein-energy malnutrition, as assessed by body mass index.

Adolescent↗
PubMedDate not supplied

Widespread hematogenous metastases and Trousseau's syndrome in gastric adenocarcinoma.

A case of widespread hematogenous metastases and Trousseau's syndrome is reported in a 40 year-old white housewife with gastric cancer, presenting subdural hematoma, ecchymoses, epistaxis, stomach and uterine bleeding. After undergoing hematoma drainage, she was unsuccessfully treated with platelets, red blood cells, plasma cryoprecipitate transfusions, and antibiotics. Necropsy disclosed gastric ring-signet adenocarcinoma invading the serous layer, with massive disseminated intravascular coagulation and systemic neoplastic embolism. Multiple old and recent hyaline (rich in fibrin and platelets) microthrombi, and tumor emboli were observed in the bone marrow, meninges, liver, lungs, kidneys, lymph nodes, adrenals, thyroid, heart, pancreas, and ovaries (Krukenberg tumor).

Adult↗
PubMedDate not supplied

Altering glomerular epithelial function in vitro using transient and stable transfection.

Damage of the glomerular filtration barrier leads to proteinuria and progressive renal failure. Several independent lines of research have implicated the glomerular epithelial cell (GEC) as a key player in initiation and propagation of pathways leading to glomerulosclerosis. A growing number of molecules activated in this process have been identified. To further define their cellular function, manipulation of these molecules using pharmacological or genetic approaches in tissue culture systems are required. In this study, strategies for altering GEC gene expression by transient and stable transfection of fluorescence labeled proteins will be presented and discussed. The insight gained through these and comparable systems should allow a detailed dissection of the molecular pathways active in GEC function and failure.

Cells, Cultured↗