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Biomedical subjects

M E Silva

Publications and source records attributed to M E Silva.

At least 55 records · Page 3Linked to original sources
PubMed1987

Effects of a high-carbohydrate diet on blood glucose, insulin and triglyceride levels in normal and obese subjects and in obese subjects with impaired glucose tolerance.

1. The present study was performed in order to assess the influence of a high-carbohydrate diet on carbohydrate and lipid metabolism in humans. 2. Short-term (3 weeks) and long-term (6 weeks) effects of a high-carbohydrate diet (HCD, 85% carbohydrate) were compared with the effects of 2 weeks on a diet of normal carbohydrate content (ND, 45% carbohydrate). The study was conducted on 4 normal and 11 obese subjects (with normal or impaired glucose tolerance) on a metabolic ward. Fasting blood glucose, insulin and triglyceride levels were measured twice a week. Tolerance to carbohydrates was evaluated by measuring blood glucose and insulin levels after oral and intravenous glucose loads and liquid meals at intervals throughout the 8-week period. 3. Long-term HCD improved the tolerance to oral glucose, i.e., it decreased serum glucose and insulin responses to an oral glucose load. 4. HCD had no effects on fasting levels of glucose or insulin or on the tolerance to an intravenous glucose load. 5. A high-carbohydrate liquid meal induced greater post-prandial glucose and insulin levels than a normal liquid meal. 6. In a second group of 6 normal and 6 obese subjects, efficacy of the liquid meal tests was evaluated. A high-carbohydrate liquid meal induced greater glucose and insulin responses than a normal liquid meal during both dietary periods. 7. Fasting triglyceride levels increased and remained high throughout the HCD period.

Adult↗
PubMed1986

Glucose in human semen.

The glucose content of normal human semen amounts to 0.41 +/- 0.09 mmol/l. As there is a negative correlation between this sugar and sperm motility, it must have an important role on the metabolism of these cells. Cervical mucus is very rich in glucose and does not contain fructose. This confirms utilization of glucose by spermatozoa.

Fructose↗
PubMed1981

Animal wastes. II. Chemical and nutritional evaluation of by-products from rennet and proteases production.

Drum-dried calf stomach waste (DDSW) from rennet production, after washing with water for salt elimination, as well as drum-dried porcine pancreas waste (DDPW) from protease extraction were used. Their chemical composition and nutritional values were studied. The protein content of DDPW was two-thirds that of the DDSW sample. The amount of ashes (acid soluble and insoluble) in DDPW was twice that of DDSW. Four diets, the protein sources of which were casein, DDSW, DDPW and a mixture of equal parts of both by-products (MSPW) were then prepared. Their nutritive value was assessed in weanling rats through the following parameters: food ingestion, body weight gain, protein efficiency ratio (PER) and and apparent protein digestibility. The DDSW sample showed the lowest nutritional quality for all parameters measured. The weight gain of rats fed diets containing casein, DDPW, MSPW, and DDSW were, 59.60 +/- 8.12, 84.63 +/- 9.89, 56.22 +/- 6.74, and 20.08 +/- 3.72, respectively. The PER for the same diets were: 2.82 +/- 0.33, 2.67 +/- 0.19, 2.17 +/- 0.25, and 1.30 +/- 0.20, in the same order. The protein digestibility of all experimental diets was about 70%, and that of the control diets, about 90%. As a conclusion, the by-product of protease production from porcine pancreas seems adequate as a protein source for animal feeding, despite its high level of ashes. Also, this by-product appears to be useful for feeding purposes, when mixed with the other animal by-products studies.

Animals↗
PubMed1979

On the degradation of heparin by human blood platelets.

Human blood platelets are able to degrade heparin from different tissues and species. The main degradation product is an oligosaccharide. Low molecular weight components such as inorganic sulfate or monosaccharides, i.e. products released by exoenzymes are not detected. The in vitro degradation of heparin by the crude enzyme is observed at pHs below 6.5 with an optimum temperature around 37 degrees C. The presence of sulfate in the substrate structure is shown to be essential for the enzyme activity. Since the oligosaccharides formed have only 10 per cent of the anticoagulant activity of the heparins tested, it is conceivable that the platelet enzyme may play an important role in the inactivation of some of the biological properties of heparin.

Blood Platelets↗
PubMed1975

Structure of heparin. Characterization of the products formed from heparin by the action of a heparinase and a heparitinase from Flavobacterium heparinum.

The total degradation of heparin by the joint action of a purified heparinase and a heparitinase from Flavobacterium heparinum is reported. The heparinase acts directly upon heparin, yielding 52% of a trisulfated disaccharide (O-(alpha-L-ido-4-enepyranosyluronic acid 2-sulfate)-(1leads to 4)-2sulfoamino-2-deoxy-D-glucose 6-sulfate) and 40% of a tetrasaccharide besides small amounts of hexa- and disaccharides. The tetrasaccharide is in turn completely degraded by the heparitinase, forming trisulfated disaccharide and disulfated disaccharide (O-(alpha-D-glyco-4-enepyranosyluronic acid)-(1leads to 4)-2-sulfoamino-2-deoxy-D-glucose 6-sulfate) in equal amounts. These and other results indicate that the tri- and disulfated disaccharides are linked alternately, in a proportion of 3:1, respectively. The primary structure of heparin and the mode of action of the heparinase and the heparitinase are proposed based on the analysis of the different products formed by the action of the enzymes.

Flavobacterium↗
PubMedDate not supplied

The effect of chronic ingestion of ethanol on modulation of granulomatous inflammation in experimental schistosomiasis in mice.

We studied the role of ethanol on the modulation of liver granulomata around Schistosoma mansoni eggs in mice. Albino mice, receiving 7% ethanol as the sole drinking liquid, at 60 and 90 days post-infection, presented smaller granulomata than controls did, when sacrificed at 120 days post-infection. No differences in diameters could be observed, when ethanol was given 4 months before up to 120 days after infection. The results suggested that modulation of schistosome granulomata by ethanol ingestion varies with time and duration of drug consumption.

Animals↗
PubMedDate not supplied

Influence of dietary protein content on Trypanosoma cruzi infection in germfree and conventional mice.

Germfree (GF) and conventional (CV) mice were fed on diets containing 4.4, 13.2 or 26.4% of protein (weight/weight). CV mice fed on low protein diet did not gain weight during four weeks, whereas the protein deficient diet did not affect the growth of GF mice. After four weeks on these diets, the mice were inoculated with 5 x 10(3) trypomastigotes of Trypanosoma cruzi. The protein deficiency affected less the GF than the CV mice, according to the following parameters: weight gain, hemoglobin, plasma protein and albumin levels and water and protein contents of the carcass. Infection with T. cruzi produced a significant decrease in hemoglobin levels, red blood cell count, and water and protein contents in the carcass. This decrease was more pronounced in the GF mice. Histopathologically, there was no difference between the treatments in animals with the same microbiological status (GF or CV). However, the disease was more severe in the GF than in the CV mice.

Animals↗
PubMedDate not supplied

[Protein hydrolysate as a dietetic resource]

OBJECTIVE: The central goal of this paper was to study the application of beef meat and poultry (turkey and chicken) hydrolysates to the preparations used in our Brazilian current feeding practices. METHODS: The various kinds of meat were hydrolyzed with fresh pineapple under similar conditions to those daily used at home. The selection of three types of preparation was dependent on whether their contents included starch or gelatin and liquid, like soup, mousse and fruit-shake. Hydrolysate were added to the preparations as part of the liquid content of their recipes. The acceptability of the preparations was checked out by employing the hedonic-scale affective test with untrained tasters. Variance analysis and the Tukeýs test were performed with a 5% level of significance for the results.RESULTS: The selected recipes were the following: bitterroot soup, fruit and vegetable-shakes and grape mousse, all of them containing starch or gelatin as an element to camouflage the bitter taste of the aminoacids. The preparations were well accepted: approximately 76% of the tasters reported having liked the soup at least somewhat; as to the shakes, more than 50% gave positive answers, and as to the mousse, approximately 88% reported having liked it. There were no statistically significant differences (p< 0.05) concerning the application of the three hydrolysates in all the preparations tested. CONCLUSIONS: The use of hydrolysed meat to replace liquid content of recipes is highly practicable, requiring only an adequate selection of recipes and their ingredients, that should include starch and gelatin in order to get fully satisfactory products. These preparations might serve as a basis for other ones, adapted to each diet.

Journal Article↗
PubMedDate not supplied

[Does heart sarcoma mimick lupus erythematosus and vasculitis? Report of 2 cases].

Primary heart tumors are rare. The most common one is myxoma. It may synthetize IL-6 and frequently shown systemic clinical manifestations that confuse the diagnosis. Primary heart sarcomas are even more rare, as far as we know they have been not associated with systemic illnesses. We observed two cases with a presumptive diagnosis of systemic lupus erythematosus who were identified as primary sarcomatous heart neoplasms after surgical excision.

Adult↗
PubMedDate not supplied

Bacteriological and immunological aspects of conventional and germfree mice infected with Salmonella typhimurium.

Bacterial invasiveness and immunological responses were studied in germfree (GF) and conventional (CV) mice infected with Salmonella typhimurium. Bacterial counts of homogenates prepared from liver and spleen showed that the colony forming units (CFU) increased rapidly in GF mice and reached lethal proportions (10(9) cell per organ) by day 6. In CV mice, these counts increased to about 10(4.5) log cell per organ by day 6 and then declined slowly. An increase in serotype-specific IgM and IgG levels was noted in CV mice with a maximum by day 2. Very low values of these IgM and IgG were observed in GF mice during the course of infection. Delayed type hypersensitivity (DTH) response as measured by footpad swelling was higher in CV animals. Higher hypersensitivity to LPS during infection in GF animals resulted in death of all the animals tested for DTH after day 2. The data obtained suggest that during a rapid invasive bacterial infection, the slow development of immune response of GF mice may result in death of these animals.

Animals↗
PubMedDate not supplied

[Structural changes in pulmonary vessels and coronary arteries in hypoplastic left heart syndrome].

In order to correlate gross morphological features with pulmonary and coronary vasculature changes in hypoplastic left heart syndrome (HLHS) 15 heart-lung necropsy specimens from neonates were analysed. Histology of left atrium wall, lung vessels with pulmonary arteriolar disease morphometric grading, study of intra and extra pulmonary wall veins and coronary arteries were recorded. Classic HLHS was observed in 11, and DORV with mitral atresia in 4, the foramen ovale (FO) being the only left atrium outflow tract in all. All specimens had increased % of thickness and muscular extension of arterioles and increased wall thickness of pulmonary veins, but severer arteriolar and venous changes with left atrium fibrosis were noticed in 8 specimens with either closed FO (3 cases) or mean FO diameter (d) of 5 mm when compared with specimens with mean FOd of 9 mm. Coronary arteries histology disclosed in 4 of 8 specimens with opened but hypoplastic mitral valve, intima proliferative changes with lumen narrowing, not observed in 7 specimens with mitral valve atresia. We concluded that in HLHS closed or restrictive FO and permeable mitral valve may predispose neonates to respiratory complications, right ventricle abnormal function and arrhythmias, specially after cardiac surgery.

Aorta↗