Rat models of protein and protein-energy malnutrition.

Two animal models of infantile malnutrition were produced where some aspects of carbohydrate metabolism can be studied: protein-depleted (PD, "kwashiorkor") rats, fed a protein-free diet for 18 days, starting 3 days before weaning, and chronically malnourished animals during suckling (PED, "marasmus") where 20-22 pups were fed by the same dam. PED and PD rats were sacrificed at 21 and 36 days of age, respectively. Body weight was 35% in PD, and 50% in PED groups when compared to their age-matched controls. After an overnight fast, some of the PD animals presented with low blood glucose levels, and the levels of lactic and pyruvic acids were depressed in PED, while lactic acid was increased in PD animals. Blood glucose utilization was reduced in PED, and increased in PD rats, while the opposite was true for the kidney gluconeogenic capacity. When compared to the respective control values, muscle glycogen was high in both groups, while the level of liver glycogen was unchanged. The rate of muscle glycolysis was decreased in both groups. These results are in agreement with clinical observations, suggesting that these models may be used to study some of the metabolic changes brought about by infantile malnutrition.

[Influence of previous cooking on the biological value of sardine protein concentrates, obtained by extraction with ethanol]. / Influência da cocção prévia no valor biológico de concentrados proteicos de sardinha, obtidos por extração com etanol.

The authors studied the effect of previous cooking on the residual content of lipids and on the biological value of the fish protein concentrates (FPC) from Sardinella aurita. The extraction of lipids was done with ethanol at 95%. It was observed that previous cooking facilitates the extraction, decreasing the residual content of lipids at a level of 0.72% in the FPC submitted to previous cooking, and at a level of 1.05% in the FPC not submitted to previous cooking (P greater than 0.05). The aminogram indicated that threonine was the primary limiting amino acid in relation to the FAO reference protein. The biological test of the protein of FCP in 21 day-old weanling male rats of the Wistar strain, was studied through the food and protein efficiency ratio (FER and PER), apparent digestibility (Dap), and net protein utilization (NPU). The biological value obtained was between 46 and 44%, respectively, for the fish protein concentrate, with and without previous cooking (P greater than 0.005).

[The influence of the quality of proteins in fluoride bone fixation]. / Influencia da qualidade da proteina na fixacao ossea do fluor.

45 rats Wistar, 30 days old, were divided into five groups, receiving different diets: casein, bean and wheat flour. The last two diets were supplemented or not by D-L Methionine and D-L Lysine, respectively. Diets and fluoridated water (25 ppm) were given "ad libitum" for 28 days. After this period of experience, the animals were sacrificed and the mandible and the tibias removed for analyses of fluoride, calcium, phosphorus and ash. The A.A. main conclusions are the following: The fixation of fluorides in bones is significantly increased with the supplement of the limitant factor to dificients diets. In this condition, the mandible shows smaller fixation of fluorides than tibias. The level of calcium, phosphorus and ash shows to be similar in the diferentes groups. This data suggests interaction of the protein quality and the percentual fixation of fluorides, and the necessity of further studies about this problem.

[Bromatological study of protein concentrates from Sardinella aurita and Tilapia melanopleura. II. Analysis of minerals]. / Estudo bromatológico de concentrados proteicos obtidos a partir da Sardinella aurita eda Tilapia melanopleura II. Ensaio dos minerais

The calcium and phosphorus of fish protein concentrates (FPC) prepared from whole sardines or tilapias have high biological availability, but the mineral fraction as a whole did not support the normal growth of young rats. Fluoride absorption and utilization is low; the amount retained in the carcass of rats depends on the amount given in the diet according to the equation: Y=0,0672X + 0,202 Y=mg of fluorine retained X=ppm of fluorine in the diet In case of sub-optimal levels of mineral ingestion, fluoride fixation increased proportionally to the deficiency. Our results demonstrate that does not seem necessary to reduce the amount of fluoride in FPC intended for human consumption, at least for people without mineral deficiency in the diet. Results concerning the Ca, P and F balance in rats are presented.

[Bromatological study of protein concentrates from Sardinella aurita and Tilapia melanopleura. III. Effects of potassium suplementation on the biological value]. / Estudo bromatolotico de concentrados proteicos obtidos a partir da Sardinella aurita eda Tilapia melanopleura III. Effeito da suplementacao com potassio sobre ovalor biologico

Bromatological study of protein concentrates from Sardinella aurita and Tilapia melanopleura. III. Effect of potassium additions on the biological utilizations. The authors studied in rats, the effect of suplementation of fish protein concentrates with Ca, P, K, or Na. Only the addition of K, but not of Ca, P, or Na resulted a better utilization of protein, showing to be the major deficiency of the mineral fraction of the concentrates.

[Influence of aflatoxin B1 on growth of rats under various nutritional conditions]. / Influencia de aflatoxina B1 sobre o crescimento de ratos submetidos a diferentes condições nutricionais.

The effect of the addition of aflatoxin B1 was studied in 48 male, Sprague-Dawley rats weaned at 21 days of age. The animals of the experimental group received one of the following diets to which aflatoxin B1 was added (5 mg/kg ration), a protein-free diet, the regional basic diet of Northeast Brazil (RBD) containing 9.07% protein, and commercial casein diets (at 10 and 20%). The control groups were fed the same diets without aflatoxin B1. To detect possible body alterations, the body weight and food intake, as well as protein and aflatoxin B1 intakes were recorded. Significant alterations were detected in the experimental groups, especially in the protein-depleted animals, and in those fed the RBD and 10% commercial casein diets, when compared to their controls.

The nutritive value and some biochemical aspects of single cell protein obtained from "Saccharomyces, sp.", in rat feeding.

The authors have studied the biological value (BV) of Single Cell Protein (SCP) obtained from "Saccharomyces, sp." and the probable alterations among the values of uric acid, urea, total protein (Pt) and albumin (Ab) in the serum, and among hepatic content of DNA, RNA, Pt and total lipids in Wistar male rats. The animals were fed "ad libitum" with an experimental diet containing 25% of protein of SCP (EG-25), and a control diet containing 25% protein of casein (CG-25) during 9 weeks from weaning (28 days old). The BV was significantly smaller in EG-25. The serum and urine values of uric acid were higher in the EG-25 and these data suggest homeostasis. The urea contents were higher in CG-25. The Pt and Ab did not differ. The hepatic variables: the total lipids, the cell weight, the relation protein/nucleus and the liver weight in relation to the body weight were higher in EG-25. The DNA, RNA and number of hepatic cells were lower to EG-25 as compared to CG-25 (p less than 0.05). The results also indicated that the BV of SCP at 25% was inferior to that of casein. The biochemical hepatic results may be attributed to a deficiency in total-S-amino acids in SCP. The protein synthesis in the liver doesn't seem to have suffered any alterations by the ingestion of amino acids present in the casein and in the SCP. Hepatic hypertrophy may have occurred during the acute stage of growth. The protein of SCP may have influenced the speed of cell division.

Fluoride release and physical properties of a fluoride-containing amalgam.

1. The amount and percentage of fluoride released from amalgam were less for the 1:1.6 alloy/mercury ratio than for the 1:1 ratio. 2. Higher fluoride concentrations resulted in a greater quantity but lower percentage of fluoride released from the amalgam. 3. Longer immersion times resulted in a greater amounts and percentages of released fluoride. However, the fluoride released per hour decreased with immersion time. 4. Immersion of the amalgam in lactic acid caused a greater release of fluoride than immersion in distilled water. 5. Disintegration of the amalgam was greater in lactic acid than in distilled water. The contribution of calcium fluoride to weight loss was greater in water than in lactic acid, indicating a corrosive effect for lactic acid. 6. The higher calcium fluoride content (2 per cent) decreased the compressive strength of the amalgam but did not alter the dimensional change.

[Value of proteins of the flour of cheastnuts of Pará]. / Farinha de castanha do pará valor de sua proteína

The authors have made some chemical analysis of the deffated Brazil-nut flour. The average protein content was about 46% and aminogram showed that all the essential aminoacids were present in the protein, and a high concentration of total sulfur aminoacids was found. The chemical analysis also showed an utilization of about 54% for the Brazil-nut flour and 55% for the casein. However, the biological value of the casein prepared diet was higher than that prepared with Brazil-nut flour.