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D Bustos

Publications and source records attributed to D Bustos.

26 records · Page 2Linked to original sources
PubMed1992

Effects of right hemicolectomy on nitrogen balance in the rat.

Rats with right hemicolectomy were divided into two groups. One group was free-fed (RHFF), the other group pair-fed (RHPF) and both were compared with a group of control animals. The nitrogen balance (NB) was studied for 5 days at 2 and 14 weeks after surgery. The two groups of rats with right hemicolectomy excreted significantly more fecal nitrogen than the control group (p less than 0.01) during the two periods of study. At 2 weeks the RHFF group increased N intake so that their NB was similar to that of the control group. In the same period the nitrogen lost in urine and the NB were reduced in the RHPF rats (p less than 0.01). At 14 weeks the results were similar to those for 2 weeks although the increase in food intake for RHFF and the decrease in NB for RHPF were not statistically significant. The rats with right hemicolectomy showed a decreased gain in body weight. This decrease was more pronounced in the RHPF group. The nitrogen content of the carcass and liver was significantly reduced in the RHPF group 4 months after surgery. It is concluded that the rats with right hemicolectomy were characterized by an increment in the nitrogen lost in feces, and when they were only allowed the same intake of food as the control group, the animals showed marked abnormalities in growth and in the nitrogen content of the organism.

Animal Nutritional Physiological Phenomena↗
PubMed1991

Effect of loperamide and bisacodyl on intestinal transit time, fecal weight and short chain fatty acid excretion in the rat.

We analyzed the effect of drugs that modify the colonic motility on rat intestinal transit time (ITT) (measured with radiopaque markers), fecal weight (FW) and fecal concentration of short chain fatty acids (FSCFA) (assayed by gas liquid chromatography), over a four-week period. Bisacodyl was used to accelerate and Loperamide to retard the intestinal transit in rats maintained on a conventional diet. The first and 3rd week were drug-free control periods. The mean values of these periods were: ITT = 28.9h +/- 1.9 FW: 9.2 +/- 1.2 g/24 h and FSCFA = 60.6 +/- 17.9 mmol/g. After loperamide administration, we observed an increase in the mean ITT as compared to the control period (40.4 +/- 8.0h) and decrease in FW (4.8 +/- 3.6 g/24h) and in FSCFA = 32.2 +/- 5.6 mmol/g). After bisacodyl administration, we found a shorter ITT in relation to controls (24.8 +/- 2.5h), and increases in FW (27.5 +/- 3.6g/24h) and in FSCFA (108.2 +/- 39.9 mmol/g). There was a negative correlation between ITT and FW (R = 0.67 p less than 0.01) and a positive correlation between total SCFA concentration and FW (R = 0.71 p less than 0.01). The concentration of acetic, propionic and butyric acids increased with progressive increments in fecal weight, whereas concentrations of isovaleric and caproic acids decreased. The results of this study show that the FW and the FSCFA may be influenced by modifications in the intestinal transit time.

Animals↗
PubMed1990

[Failure of prevention of malaria by mefloquine in West Africa].

Mefloquine (Lariam) is extensively prescribed for the prevention of malaria in chloroquine-resistant areas. However, in west Africa, most of the strains of Plasmodium falciparum are still sensitive to chloroquine. In addition, a few of these strains are inherently resistant to mefloquine. Under these conditions, we must expect to see the failure of mefloquine prophylaxis in travellers returning from west Africa. We report here 5 such failures. The in vitro susceptibility of Plasmodium falciparum isolates from 4 of these patients was evaluated and showed that all 4 had normal sensitivity to chloroquine and quinine, 3 were resistant to mefloquine and one had reduced susceptibility to mefloquine. Mefloquine blood levels (measured 3 times) were within the normal protective range. These case reports indicate that mefloquine should be used cautiously for malaria prevention in west Africa. They also point out that, regardless of the prophylactic method used, fever in a traveller returning from endemic malaria regions always dictates the analysis of a thick blood smear to rule out the diagnosis of malaria.

Adult↗
PubMedDate not supplied

Cloning of a fresh isolate of Plasmodium falciparum and drug sensitivity of the clones.

A freshly isolated strain of Plasmodium falciparum was cloned by limited dilution using a co-culture of infected erythrocytes on monolayers of functionally active rodent hepatocytes. 15 clones were isolated, and the anti-malarial activity of chloroquine, quinine, mefloquine and halofantrine against the clones, the original isolate, and a culture-adapted isolate was determined using a 48 h radioisotope microdilution method. The multiplication rates of all clones and the culture-adapted isolate were estimated by counting the number of parasitized cells on Giemsa-stained thin smears. Variations found in drug sensitivity and multiplication rate of different clones provided strong evidence of heterogeneity of a single strain parasite population. No morphological variation was detected by light microscopy. The use of a hepatocyte feeder layer improved the adaptation of cloned parasites to continuous culture conditions and thus enabled us to clone directly a fresh isolate, without losing clones during the culture-adaptation process.

Animals↗