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Biomedical subjects

A Lopez

Publications and source records attributed to A Lopez.

At least 289 records · Page 16Linked to original sources
PubMed1983

Moderate and severe protein energy malnutrition in childhood: effects on jejunal mucosal morphology and disaccharidase activities.

The enzymatic activities of maltase, sucrase, and lactase were determined in jejunal biopsies obtained from 24 children with gastrointestinal symptoms and different degrees of protein energy malnutrition (PEM) to see if these differences were related to the extent of malnutrition or concomitant small intestinal mucosal injury. Even in patients with moderate PEM, lactase activities were significantly lower than control values. The decrease in lactase activity seemed to depend on the severity of malnutrition. In contrast, maltase and sucrase activities were decreased only in second and third degrees of PEM, while no significant changes were observed in first degree and marasmic kwashiorkor. Histologically, all children with PEM had grade I to II mucosal injury which did not correlate with the degree of malnutrition. These results indicate that PEM affects each of the disaccharidases of the jejunal mucosa differently, with lactase being most sensitive to PEM and reflecting most closely the degree of PEM. In contrast, morphological changes showed no correlation with the degree of PEM.

Biopsy↗
PubMed1982

SEM and X-ray microanalysis of human prostatic calculi.

Calculi removed from human prostates affected with nodular hyperplasia were analyzed with scanning electron microscopy and EDAX system. The general spectrum was made up of Na, Al, Mg, S, P, Ca and Zn. Two types of stone were identified morphostructurally and microanalytically: calculi type I of nodular surface with high peaks of S, and calculi type II polyfaceted with high peaks of P and Ca. Their formation from corpora amylacea and/or exogenous constituents is discussed. The superficial deposit of Zn suggests its incorporation from the prostatic liquid and does not seem to play an important role in the genesis.

Calculi↗
PubMed1982

The pulmonary clearance of Pasteurella haemolytica in calves infected with bovine virus diarrhea or Mycoplasma bovis.

Based on current literature which commonly associates bovine virus diarrhea virus and Mycoplasma bovis with "pneumonic pasteurellosis," an investigation was conducted into the effect of these two pathogens on the capacity of bovine lung to clear inhaled Pasteurella haemolytica. There was no significant effect (p less than 0.05) of either bovine virus diarrhea virus or M. bovis on the mean clearance rate of P. haemolytica, nor did the time interval of three, five or seven days between the first inoculation and exposure to P. haemolytica and adversely affect the lung clearance rates. However, it was found that the left lungs and a higher bacterial retention (p less than 0.05) than the right lungs.

Animals↗
PubMed1981

Cytology of postbronchoscopically collected sputum samples and its diagnostic value.

The usefulness of the cytology of postbronchoscopically collected sputum (PBS) samples in the diagnosis of neoplastic lung disease has been studied in 113 cases. The overall diagnostic yield of fiberoptic bronchoscopy (FB) alone was 77%, 87% in 77 central tumors and 58% in 36 peripheral ones. With the addition of PBS, the positive results increased to 91% in the 113 cases (p less than 0.01), to 94% n central tumors (p greater than 0.05) and to 83% in peripheral lesions (p less than 0.02). In 15 cases PBS offered the unique positive results. 73 cases with histological confirmation showed a good cytohistological correlation in 82%. Our report suggests that PBS is a useful technique in the diagnosis of lung cancer. Its systematic use does not seem to be justified in central tumors, but it is of great value in peripheral tumors when fluoroscopic control is not available.

Adult↗
PubMed1981

Lung cancer model system using 3-methylcholanthrene in inbred strains of mice.

A model system has been established for studying lung carcinogenesis using intratracheal instillation of 3-methylcholanthrene in C3H/AnfCum and C57BL/Cum X C3H/AnfCum F1 (hereafter called BC3F1/Cum) mice. The animals in these studies were screened for adventitious agents and were free throughout their lifetime of two important lung viruses, Sendai virus and pneumonia virus of mice. Under these conditions, the occurrence of spontaneous and chemically indiced lung cancers was determined over the lifetime of the animals. Data were analyzed by the actuarial method for lung tumor probability. Probability was found to be dose and time dependent. Over 95% of the 3-methylcholanthrene-treated BC3F1/Cum and over 88% of the C3H/AnfCum mice were found at death to have pulmonary carcinomas. Tumors observed in animals which died up to 40 weeks on test were almost always squamous cell carcinomas (approximately 85%), while tumors which were observed in animals which died after 50 weeks were mainly alveolar adenocarcinomas (approximately 80%). Both tumors types metastasized widely. Spontaneous lung cancers (only alveolar adenocarcinomas were observed) occurred in these two strains at low frequency and were expressed late in life. Thus, the system described affords a suitable model to study the induction, expression, and progression of lung tumors under conditions where a vast majority of animals develop neoplasia.

Animals↗