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Biomedical subjects

M L Vidal

Publications and source records attributed to M L Vidal.

13 recordsLinked to original sources
PubMed2005

Changes in eggshell mechanical properties, crystallographic texture and in matrix proteins induced by moult in hens.

The effect of moult on eggshell mechanical properties, on composition and concentrations of organic matrix components and on eggshell microstructure was investigated. The observed changes were studied to understand the role of organic matrix and eggshell microstructure in eggshell strength. Moult was induced by zinc oxide (20 g zinc/kg diet) in 53 ISA Brown laying hens at 78 weeks of age. No difference was observed for egg or eggshell weights after moult. In contrast, moult improved the shell breaking strength (28.09 vs 33.71 N). After moult, there was a decrease in the average size of calcite crystals composing the eggshell and in their heterogeneity, whereas crystal orientation remained basically the same. After moulting, the total protein concentration in eggshell increased slightly. The comparisons of SDS-PAGE profiles of the organic matrix constituents extracted before and after moulting showed changes in staining intensity of certain bands. After moult, bands associated with main proteins specific to eggshell formation (OC-116 and OC-17) showed higher staining intensity, while the intensity of the egg white proteins (ovotransferrin, ovalbumin and lysozyme) decreased. ELISA confirmed the decrease in ovotransferrin after moult. Its concentration was inversely correlated with breaking strength before moult. These observations suggest that changes in eggshell crystal size could be due to changes in organic matrix composition. These changes may provide a mechanism for the improvement in shell solidity after moulting.

Animals↗
PubMed2001

Interest of a multibiomarker approach in the assessment of freshwater ecosystem quality: laboratory and field studies.

The aims of this study were to validate several biochemical parameters as biomarkers of pollution in the freshwater bivalve Corbicula fluminea and to underline the interest of a multibiomarker approach in environmental biomonitoring. The study was divided into a laboratory exposure to 4 doses of trichloroethylene, toluene, cadmium chloride or a coal tar fraction for 5 days and a field exposure for one week in 5 sites surrounding an industrial effluent outlet. Whatever the product was, parameters that exhibited significant responses were mainly parameters related to oxidative stress and components of phase I metabolism. As a result of discriminant analysis, doses were clearly discriminated from the control and from each other. Likewise, products were discriminated from each other, based on results of the whole parameter responses obtained for the first dose. Concerning the field experiment, all biochemical parameters assayed exhibited significant responses for sites located downstream of the effluent outlet, compared to the upstream reference site. Through a discriminant analysis, sites could be distinguished from each other in terms of pollution intensity. In order to characterise pollution at a qualitative level, further laboratory and field studies are needed to obtain typical profiles for the main pollutants present in freshwater ecosystems.

Animals↗
PubMed1998

Nutritional control of pregnant women on chronic hemodialysis.

The authors describe their experience in the follow-up of four patients with chronic renal failure who became pregnant while being treated with chronic hemodialysis. The outcomes were successful and each gave birth to healthy babies. The adequate nutritional condition previous to the pregnancies added more safety to their management. Special dedication to the nutritional control enabled a good outcome of their pregnancies. It stressed the importance of the intervention of the nutritionist-dietitian in the follow-up of nephrologic patients and the integration of a multidisciplinary staff.

Adult↗
PubMed1997

Tolerance of pyrazinamide in short course chemotherapy for pulmonary tuberculosis in children.

BACKGROUND: This prospective study was performed to evaluate the tolerance of pyrazinamide in short course chemotherapy in children. METHODS: A total of 114 children ages 6 months to 15 years (4.5 +/- 3.4 years) with diagnosed pulmonary tuberculosis from 1985 to 1995 entered the trial. A 2-month regimen of isoniazid, rifampin and pyrazinamide, followed by rifampin and isoniazid for the remaining 4 months, was administered orally to all children. Clinical adverse effects specifically investigated were gastrointestinal disturbances, rash, signs of hepatotoxicity and arthralgias. Laboratory toxicity data (number of leukocytes, erythrocyte sedimentation rate, aspartate aminotransferase, alanine aminotransferase and serum uric acid) were collected before treatment and 1, 3 and 5 months after the beginning of chemotherapy. RESULTS: Clinical adverse effects were mild in all cases. Three children (2.6%) had fever and 5 (4.4%) had gastrointestinal disturbances. Aspartate aminotransferase and alanine aminotransferase mean values showed no differences along time and no patients had clinical signs of hepatotoxicity. Only 11 children (19.6%) showed a slight increase in alanine aminotransferase (< 194 units/l). Serum uric acid increased in 92.2% of the children compared with pretreatment values. This increase remained within the normal range in all but 9.8% of patients. There was a significant increase in uric acid mean concentrations after 1 month of therapy (from 3.7 +/- 0.7 mg/dl to 5.7 +/- 1.6 mg/dl, P < 0.05), which fell again (4.0 +/- 1.1) 1 month after pyrazinamide was stopped. There were no signs of gout or arthralgias. In no case was the treatment interrupted. CONCLUSION: The addition of pyrazinamide in chemotherapy for pulmonary tuberculosis in children was found to be safe. The slight increase in uric acid concentration during its administration had no recognized adverse consequences.

Adolescent↗
PubMed1986

[Abdominal tuberculosis in children. A review apropos of 13 cases].

Thirteen cases of abdominal tuberculosis are presented; some of them in active or symptomatic stage and others in latent or abdominal calcification form. Many of these patients were diagnosed through the finding of a source of infected cattle after diagnosis of one of symptomatic patients. Pathogenesis, clinical findings and diagnostic difficulty are commented, as well a sanitary importance of the problem, since M. bovis is still a currently found organism in daily practice.

Adolescent↗