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Biomedical subjects

J M Rubio

Publications and source records attributed to J M Rubio.

49 records · Page 3Linked to original sources
PubMedDate not supplied

Effect of chronic ethanol on D-galactose absorption by the rat whole intestinal surface.

The in vivo absorption of D-galactose by rat whole intestinal surface after 4 weeks of 30% ethanol ingestion in drinking water has been studied, and the results were compared with ad lib-fed control rats. The total serosal intestinal area was determined by integration obtaining similar values between control and alcohol-treated groups. In the caecum surface of ethanol-fed rats slight but not significant increases were found, while the jejunum area decreased with respect to control rats. Total galactose absorption during 10 min of perfusion was slightly increased in ethanol-fed rats but these results were not significant with the substrate concentrations tested. When absorption data were referred to serosal surface, the absorption/cm2 values in ethanol-fed rats were increased at the studied galactose concentrations although these results were only statistically significant at 10 mM. In conclusion, the present data indicates a slight increase in D-galactose absorptive capacity by the whole intestine in ethanol-fed rats which suggest that the tissue traditionally not evaluated such as caecum and colon could modify the functional response to the absorption nutrients.

Animals↗
PubMedDate not supplied

Genotyping of Plasmodium falciparum infections by PCR: a comparative multicentre study.

Genetic diversity of malaria parasites represents a major issue in understanding several aspects of malaria infection and disease. Genotyping of Plasmodium falciparum infections with polymerase chain reaction (PCR)-based methods has therefore been introduced in epidemiological studies. Polymorphic regions of the msp1, msp2 and glurp genes are the most frequently used markers for genotyping, but methods may differ. A multicentre study was therefore conducted to evaluate the comparability of results from different laboratories when the same samples were analysed. Analyses of laboratory-cloned lines revealed high specificity but varying sensitivity. Detection of low-density clones was hampered in multiclonal infections. Analyses of isolates from Tanzania and Papua New Guinea revealed similar positivity rates with the same allelic types identified. The number of alleles detected per isolate, however, varied systematically between the laboratories especially at high parasite densities. When the analyses were repeated within the laboratories, high agreement was found in getting positive or negative results but with a random variation in the number of alleles detected. The msp2 locus appeared to be the most informative single marker for analyses of multiplicity of infection. Genotyping by PCR is a powerful tool for studies on genetic diversity of P. falciparum but this study has revealed limitations in comparing results on multiplicity of infection derived from different laboratories and emphasizes the need for highly standardized laboratory protocols.

Analysis of Variance↗
PubMedDate not supplied

Discovery of a new focus of human onchocerciasis in central Brazil.

An autochthonous case of human onchocerciasis was reported 13 years ago in the town of Minaçu, northern Goiás (Brazil), but a subsequent survey of the population using the traditional technique of examining skin biopsies with the light microscope failed to detect other cases. Recent surveys using more sensitive diagnostic techniques (serodiagnosis, DNA probes, Mazzotti test) that are detailed in this paper revealed the presence of other cases of the disease in Minaçu, the nearby town of Formoso and at the Buracão gold mine near Paranã. The data show that transmission of the disease has occurred to local people living in town and on farms and that gold miners (garimpeiros) are a likely source of infection.

Adolescent↗
PubMedDate not supplied

The effect of ethanol on intestinal L-leucine absorption in rats.

The chronic effect of ethanol on leucine absorption by the whole rat intestine (between duodenum and rectum) was studied using an in vivo multiple-pass perfusion technique. Leucine concentrations in the perfusion medium were 5, 10 and 25 mM respectively in successive passes. Ethanol was administered in drinking water during a one month induction period and then for a four week period of ad libitum ingestion of 30% ethanol solution. The results were compared with ad libitum-fed control rats. The total calorie consumption due to the chow diet plus ethanol increased in the rats which had ingested ethanol when compared with that of the controls. The daily protein intake in ethanol-fed rats was less than that of the controls. No significant differences in morphometric tissue parameters were found between the two experimental groups. Chronic ethanol ingestion provoked a slight (but not significant) decrease in net leucine absorption at 5 mM leucine concentration. In contrast, minor increases in the absorption values were found at 10 and 25 mM leucine concentrations. These findings suggest that the diminished active mechanisms of leucine absorption provoked by ethanol ingestion are compensated for by the enhanced diffusive processes, the passage of the nutrients through the whole intestine, and that the low protein consumption of ethanol-fed rats in ad libitum conditions isn't enough to provoke significant decreases in leucine absorption by the whole intestine.

Administration, Oral↗