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Biomedical subjects

S M Lopes

Publications and source records attributed to S M Lopes.

10 recordsLinked to original sources

[Use of diet containing yeast protein (Saccharomyces cerevisiae): effects upon pregnancy, lactation and development in rats].

The nutritive value of manioc flour (Manihot esculenta) enriched with yeast protein (Saccharomyces cerevisiae) added to a food mixture most frequently consumed by low-income populations was assessed in female Wistar rats (n = 30; 100-120 days old). Animals were divided into three groups, mated and had free access to diets and water. Diets were as follows: beans, rice, yeast-enriched manioc flour (BRYMF17); beans, rice, manioc flour (BRMF13); casein (17% protein) (CAS17). Body weight gains and food consumption were recorded during pregnancy and lactation. At the parturition, the number of pups per litter was recorded and offspring were uniformly distributed (7 pups per litter). Weight gains were determined until weaning (21 days). At weaning two youngs were selected from each litter and individually housed. Weight gains, food consumption and the length of the tail were measured until rats were 70 days old. Rats had their liver and brain removed for protein determination and wet and relative weights. Liver samples were histologically examined. Blood hemoglobin, hematocrit and proteins, as well as the Food Efficiency Ratio (FER), were determined. ANOVA and Tukey's test were used. The experimental diet had not significant effect on pregnant and lactating dams. Values for the investigated parameters were higher in experimental youngs than in their controls and lower than in the standard group. This yeast protein-enriched manioc flour proved to be valid in terms of dietary supplementation.

Analysis of Variance↗

[The use of a multimix as a dietary supplement: study in rats].

A Multimistura (MM)--sweet cassava (Manihot esculenta Crantz) leaf flour, wheat bran (Tritium aestivum L.), egg shell powder, pumpkin (Cucurbita Spp) and sunflower (Heliantus annus) seed flours--was added to a mixture of Beans, 7% (Phaseolus vulgaris) and Rice, 3% (Oryza sativa) and its effects, were assessed in weanling, male albino (Wistar) rats (n = 60). Animals were divided into 6 groups: groups 1, 2 and 3 were fed beans + rice + multimixture (B + R + MM), beans + rice (B + R) and 10% Casein, respectively; the remaining groups were maintained on a protein-free diet (PFD) for 14 d and then submitted to the same feeding protocol. Microbiological assays were performed in all MM samples. The Coefficient of Digestablity (CD), the Food Efficiency Ratio (FER), Protein Efficiency Ratio (PER), Net Protein Utilization (NPR), serum hemoglobin (Hb) and hematocrit (Ht), carcass total lipids were determined. Rats had their liver, brain, gonads, testes, spleen and left kidney removed for wet dry weights. Liver samples were histologically examined. The Mann-Whitney test was used. The protein content of B + R diet increased slightly after MM addition (0.23 g/100 g). Three out of four MM samples had moulds and yeasts. CD values were 90% and 70% for casein and B + R + MM-fed rats, respectively. The highest values for FER, PER and NPR were seen in the casein-fed rats without protein depletion. The casein-fed group had heavier organs (wet and dry weights) and higher values for carcass fat and serum Hb and Ht. Steatosis was present in both groups, with or without protein depletion. Short or long-term MM consumption, at least under our experimental conditions, had no significant effects on investigated parameters.

Animal Nutritional Physiological Phenomena↗

Essential fatty acid deficiency and home total parenteral nutrition patients.

The requirements for essential fatty acids in patients on home parenteral nutrition are not well described. We therefore studied the needs of 12 patients receiving parenteral nutrition for at least 4 mo (range: 4 mo-17.3 yr; mean 7.0 +/- 5.2 yr). Prior to the study, each patient had been receiving intravenous lipids either weekly or biweekly and had a triene to tetraene ratio (TTR) on plasma phospholipids performed at least annually. A TTR > or = 0.2 was considered diagnostic for essential fatty acid deficiency (EFAD). The purpose of this study was to determine the required intravenous lipid supplementation in patients on home total parenteral nutrition (HTPN). Patients with an initial TTR of < 0.2 had their intravenous lipid stopped and changes in their serum phospholipid fatty acids were followed every 3-4 wk. Nine of 12 patients had TTRs > 0.2 at some point in the study. Phase I consisted of patients who at initiation of the study had normal TTRs and were taken off lipid supplementation until their TTR became abnormal. Phases II, III, IV, and V consisted of lipid delivered in total nutrient admixtures in biweekly doses of 0.6, 1.2, 1.8, and 2.4 g of fat/kg bodyweight, respectively. Eight patients normalized their TTRs on the biweekly lipid regimens; one patient expired before his ratio normalized; and three patients could not be made deficient in essential fatty acids after 26 or more wk of fat-free parenteral nutrition. Most patients required 1.2 to 2.4 g of lipid/kg bodyweight/biweekly to correct serologic EFAD. The clinical background, as well as the length of small bowel remaining, did not seem to identify those patients who required lipid supplementation nor the final dose of lipid needed to normalize their TTRs.

Adult↗

Human plasma fatty acid variations and how they are related to dietary intake.

A study was conducted in 12 free-living subjects to determine quantitative and qualitative plasma phospholipid (PL), free fatty acid (FFA), triglyceride (TG), and cholesterol ester (CE) fatty acid (FA) variations over time (0.8, and 22 mo) and to correlate these FAs with dietary intake. Diet, reported by use of a food frequency questionnaire (FFQ), did not change over time. Most FA variations were quantitative, occurring in FFA and CE fractions. Correlations between diet and FAs occurred mostly in men for whom dietary percent fat energy was positively correlated with percent monounsaturated plasma TG FAs, and ethanol (g/d) was positively correlated with plasma CE 16:1 omega 7 (mumol/L). These findings indicate that quantitative variations exist in plasma FAs of a normal population, with no detectable alteration in diet; the FFQ may be used to reflect the qualitative status of plasma FA. Factors such as ethanol consumption and sex differences may influence FA metabolism.

Adult↗

Structured lipid made from fish oil and medium-chain triglycerides alters tumor and host metabolism in Yoshida-sarcoma-bearing rats.

The effects of structured lipid composed of fish oil and medium-chain triglycerides (Fish/MCT) on tumor and the host metabolism was compared with conventional long-chain triglycerides (LCTs) in Yoshida-sarcoma-bearing rats receiving TPN for 3 d. The two parenterally fed groups were divided into two treatments, saline or tumor necrosis factor (TNF), given intravenously at 20 micrograms/kg body wt. Changes in tumor volume, body weight, urinary nitrogen, whole-body and tissue protein kinetics, and fatty acid composition were measured. The study revealed that Fish/MCT feeding inhibited tumor growth, which could be attributed to decreased tumor protein synthesis. Body weight and nitrogen were better maintained by Fish/MCT feeding. In addition, the effects of Fish/MCT on tumor growth were synergistic with TNF treatment. The results demonstrate that dietary fat composition can influence fatty acid compositions of tumor tissue as well as tumor protein kinetics after a short period of TPN feeding.

Animals↗

Dietary modification of chyle composition in chylothorax.

Nutrition support has played a major role in the treatment of chylothorax, both to prevent malnutrition and to minimize chyle production and flow. This report evaluates chyle composition in a patient with chylothorax who was placed on a low-fat diet, medium-chain triglyceride diet, and total parenteral nutrition in sequence. Both triglyceride content and volume of chyle declined, but drainage persisted, ultimately requiring thoracic duct ligation. The chyle triglyceride while on total parenteral nutrition, which presumably originates from both the intestine and plasma, contained more long-chain unsaturated fatty acids than the circulating serum triglyceride. Of particular interest was the detection of an appreciable amount of medium-chain fatty acids in the chyle triglyceride, constituting 20% of the triglyceride fatty acids when an enteral formulation with medium-chain triglyceride as a sole fat source was administered. The finding of almost threefold more decanoic acid (C10:0) than octanoic acid (C8:0), despite the presence of considerably more octanoic acid in the original diet, suggests that trioctanoin may be a preferable medium-chain triglyceride substrate for the nonsurgical treatment of chylothorax.

Adult↗

Effectiveness of orthotopic liver transplantation on the restoration of cholesterol metabolism in patients with end-stage liver disease.

The effects of end-stage liver disease and orthotopic liver transplantation on components that modulate cholesterol esterification in plasma were assessed. In comparison with healthy controls, patients with end-stage liver disease had significantly decreased concentrations of lecithin-cholesterol acyltransferase mass, apolipoprotein A-1, total phospholipids, and both total and esterified cholesterol. Elevated phosphatidylcholine and reduced lysophosphatidylcholine fractions indicated impairment of cholesterol esterification by lecithin-cholesterol acyltransferase. Constituent fatty acids of the patients' phospholipids and cholesterol esters manifested increased saturation and a concomitant reduction of polyunsaturated fatty acids, indicative of impaired hepatic elongation and desaturation of essential fatty acids. By the third month after hepatic replacement, the plasma concentrations of total cholesterol, phospholipids, lecithin-cholesterol acyltransferase, and apolipoprotein A-1 were comparable to those of the healthy subjects. Despite the improvement in cholesterol esterification and the rapid normalization of the enzyme and cofactor involved in this process, the percentage of phosphatidylcholine remained significantly higher and the percentages of lysophosphatidylcholine and esterified cholesterol remained significantly lower than in the healthy subjects at 6 mo. Phospholipid and cholesterol ester fatty acid patterns attained normalcy by the sixth month after transplant. We conclude that hepatic transplantation effectively restores cholesterol and essential fatty acid metabolism in patients with end-stage liver disease.

Adult↗

Attenuation of the febrile response in guinea pigs by fish oil enriched diets.

The influence of dietary lipid manipulation on the fever response to an injection of murine recombinant Interleukin-1 (rIL-1) in guinea pigs was examined. The animals were fed diets identical except for the lipid source for periods of 5 and 6 wk. In vitro thromboxane B2/B3 (TxB2/B3) production in collagen-stimulated whole blood was also measured. One diet was enriched with menhaden oil, high in the omega-3 series of fatty acids. The other diet contained safflower oil, consisting primarily of the omega-6 fatty acid linoleic acid (74%). Animals fed the fish oil-enriched diet for 6 wk not 5 week had a blunted fever response after rIL-1 injection. This was associated with a 27% increase (p less than 0.05) in total omega-3 fatty acids in plasma phospholipids between weeks 5 and 6 in fish oil-fed animals. Safflower oil-fed animals produced a "normal" febrile response regardless of the duration of feeding. Safflower-fed guinea pigs demonstrated a significant increase in TxB2/B3 production in whole blood after 6 wks that was associated with a 25% increase (p less than 0.05) in plasma phospholipid arachidonic acid levels between weeks 5 and 6. Despite significant reductions in phospholipid linoleic acid in animals fed fish oil, arachidonic acid levels remained unchanged. In the guinea pig model used, long-term menhaden oil feeding can significantly blunt the febrile response induced by exogenous Interleukin-1. Also, a high intake of linoleic acid as seen in safflower oil feeding can significantly increase thromboxane production in stimulated whole blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗