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At least 19 recordsLinked to original sources
PubMed1977

Cultivation of Leishmania donovani and Leishmania braziliensis in defined media: nutritional requirements.

Nutritional requirements of promastigotes of Leishmania donovani and Leishmania braziliensis were studied in modifications of a simple defined culture medium. "Continuous growth," considered as propagation through 10 successive passages, was supported by inorganic salts, 14 l-amino acids (arginine, cysteine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan, tyrosine, valine), glucose, adenosine, and a mixture of 11 vitamins and related growth factors. Purified defatted bovine serum albumin proved beneficial. The nutritional needs of the above species of Leishmania differ from those of 2 other hemoflagellate species, Leishmania tarentolae and Crithidia fasciculata, for which glucose, proline and glutamine were found to be nonessential. It is suggested that lower hemoflagellates may be capable of synthesizing these substrates de novo. Leishmania donovani and L. braziliensis required higher levels of folic acid than L. tarentolae, probably due to the fact that folates are involved as cofactors in the biosyntheses of pyrimidines and serine. Although the mixtures reported here cannot be regarded as "minimal essential" media, they are considerably less complex than the ones employed so far for cultivating hemoflagellates, and are therefore well suited for studies related to nutrition and biosynthetic capabilities of Trypanosomatids.

Adenosine↗
PubMed1991

[Nutritional requirements of elderly].

Nutritional requirements of the elderly (more than 70 years old) are not yet well known. The aging-associated changes of the body composition with decrease of height, bodyweight, fat free mass, increase of adipose tissue and the decrease of physical energy expenditure modify the nutritional requirements. Owing the insufficiency of our scientific knowledge the energy and protein requirements of elderly people are assumed by W.H.O. experts as 70 p. 100 of adults' ones. Water, minerals, trace elements and vitamins requirements would be similar to those of adults. The quality of meals and their hedonic properties are important factors for the preservation of appetite.

Aged↗
PubMedDate not supplied

Nutritional requirements in parasitic diseases.

"Nutritional requirements" means different things in different contexts. Generally, the term refers to national or international standards or allowances of nutrients. Concern here involves the potential need for a change of standards where conditions of disease prevail, because disease increases the nutritional requirements of most individuals. "Nutritional requirements" may also be viewed in terms of food supplies. Analysis of a number of studies indicates that the average growth deficit due to endemic infectious diseases in early life is less than or equal to 20 kcal per day (calculated as 5 kcal/g of tissue). Increased weight gain following treatment of intestinal parasites such as Ascaris lumbricoides or Giardia lamblia provides similar estimates, as does measurement of energy and protein absorption. These values are within normal variance estimates. Sick children do not eat well and apparently do not eat enough on healthy days to correct for the accrued food deficit. Research on nutritional requirements of children needs to focus on management of food resources in entire families.

Ascariasis↗
PubMed1990

[Nutritional requirements of aged people].

The nutritional requirements of elderly people are yet not well known. Energy requirements are depending on age and bodyweight: in man between 6700 kJ/j and 9100 kJ/j, in women 6200 kJ/j and 8100 kJ/j. Protein requirements are similar in both sexes: between 50-60 grs/j. Carbohydrates and lipids are covering respectively 50-55% and 30-35% of total energy intake. Water requirements are 1,25 l/j whose at least 0,71 l/j of beverages. Mineral requirements are: 75-100 mEq/j for sodium, 12-25 mEq/j for potassium, 1000 mgrs/j for calcium, 500 mgrs/j for magnesium and 10 mgrs/j for iron. Trace elements and vitamins requirements are insufficiently known. Actually one consider that they are similar to those of adults. An energy intake of 6700 kJ/j, even if the foods are diversified, does not cover the nutritional requirements of elderly people.

Aged↗
PubMed1990

Nutritional requirements in the elderly.

Nutritional management of elderly persons can be difficult because of illness, drug-nutrient interactions, socioeconomic factors, and lack of precise information regarding nutrient requirements. Dietary intake and requirements, nutritional assessment, and guidelines for nutritional management of the elderly population are reviewed.

Adult↗
PubMed1984

Nutritional requirements of experimental fish.

Satisfactory fulfillment of the nutritional requirements of experimental fish under subchronic and chronic test conditions (such as carcinogenesis studies) is critical to the outcome of a study. Nutritional requirements of many coldwater, warmwater, and marine fishes have been determined in part by the use of semipurified diets. Generally, these diets were fed to small fish in controlled environment tanks with no supplemental food available. The control diets contained semipurified natural ingredients, or, when appropriate, purified (crystalline) nutrients and were formulated to meet the requirements (approximate) of the test species. We fed the fish representative diets to insure that their nutritional needs were met and that no adverse pathology would develop. We then modified these control diets by removing one or more of the purified nutrients to determine the essentiality of a dietary component. Later, other diets were formulated to contain different amounts of the essential nutrients, or one ingredient was substituted for another, so that the quantitative requirements could be decided. Thus we could determine the dietary requirements for protein, fat, carbohydrate, and bulk, and the qualitative and quantitative requirements for the individual amino acids, vitamins, fatty acids, and some minerals. Semipurified diets were later used in toxicity studies for the measurement of the effect of different levels of manufactured contaminants, such as insecticides, or natural toxicants, such as aflatoxin, on the well-being of fishes. Information on the preparation of semipurified diets for fishes, feeding techniques, and nutritional requirements as well as suggestions on care of small fishes in tanks appropriate for longer term carcinogenesis studies is provided.

Amino Acids↗
PubMed1985

Nutritional requirement for taurine in patients receiving long-term parenteral nutrition.

Animals fed diets lacking the amino acid taurine have low plasma and tissue levels of taurine and ultimately have retinal dysfunction. Since parenteral nutrition does not ordinarily provide taurine, we looked for evidence of taurine deficiency in 21 children and 23 adults undergoing long-term parenteral nutrition at home for an average of 27 +/- 23 (S.D.) months. The fasting plasma taurine level was reduced in children as compared with controls (26 +/- 13 vs. 57 +/- 16 mumol per liter, P less than 0.001). In adults with less than 25 per cent intestinal absorption of the recommended caloric intake, the plasma taurine level was also significantly reduced and correlated inversely with the duration of parenteral nutrition. Electroretinograms were abnormal in each of eight children who were examined. Addition of taurine to the intravenous solutions restored plasma levels to normal in four children; the electroretinograms of three of these children also became normal. The plasma taurine level became abnormally low again in two of three children one year after the intravenous taurine was discontinued. We conclude that children and possibly adults receiving long-term parenteral nutrition have a nutritional requirement for taurine.

Adolescent↗
PubMed1982

Nutritional requirements of Corynebacterium pyogenes.

The nutritional requirements of Corynebacterium pyogenes (strains C100, 5, and 1909), a commonly encountered animal pathogen, were determined in this study. A semidefined medium (SDM) containing glucose, HCO3-, hemin, charcoal-treated Trypticase, and a defined mixture of purines and pyrimidines, amino acids, and minerals which supported optimal growth of C. pyogenes was employed in all nutritional studies. Adenine and uracil were required for optimal growth of strains 5 and C100 but were not required for strain 1909. Riboflavin and nicotinic acid were required for good growth of all three strains; biotin and thiamin were stimulatory but did not appear to be required for growth. Hemin and NaHCO3 were stimulatory for growth, whereas lipoic acid and Tween 80 were neither stimulatory nor required for growth. The replacement of Trypticase with a specific peptide fraction (obtained by fractionation of Trypticase on Sephadex G-25) rich in dipeptides gave growth comparable to that in SDM, indicating a peptide requirement for the growth of C. pyogenes. It was of considerable interest that growth comparable to that in SDM was obtained when Trypticase was replaced by inositol (1 microgram/ml of SDM).

Amino Acids↗
PubMed2005

Nutritional requirements of mycelial growth of Cordyceps sinensis in submerged culture.

AIMS: The nutritional requirements for mycelial growth of Cordyceps sinensis in semi-synthetic liquid media were investigated. The results provide a basis for further physiological study and industrial fermentation of the fungus. METHODS AND RESULTS: Nutritional requirements, including 17 carbohydrates, 16 nitrogen compounds, nine vitamins, four macro-elements, four trace-elements and eight ratios of carbon to nitrogen, were studied for their effects on the mycelial growth in submerged cultures of C. sinensis by using one-factor-at-a-time and orthogonal matrix methods. Among these variables, sucrose, peptone, folic acid, calcium, zinc and a carbon to nitrogen ratio 12 : 1 were identified as the requirements for the optimum mycelial growth. The concentrations of sucrose, peptone and yeast extract were optimized and the effects of medium composition on mycelial growth were found to be in the order sucrose > yeast extract > peptone. The optimal concentration for mycelial growth was determined as 50 g l(-1) sucrose, 10 g l(-1) peptone and 3 g l(-1) yeast extract. CONCLUSIONS: Under optimal culture conditions, over 22 g l(-1) of mycelial biomass could be obtained after 40 days in submerged cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: Cordyceps sinensis, one of the most valued medicinal fungi, is shown to grow in axenic culture. This is the first report on nutritional requirements and design of a simplified semi-synthetic medium for mycelial growth of this psychrophilic species, which grows slowly below 20 degrees C. The results of this study will facilitate research on mass production of the fungus under defined culture conditions.

Carbohydrates↗
PubMed1978

Symposium on nutritional requirements of the surgical patient. 1. Nutrition and body composition.

Body composition measurements were determined by a multiple isotope dilution technique to assess nutritional status of patients and to determine the efficacy of nutritional support. The body composition of 75 patients with severe malnutrition was characterized by a contracted body cell mass with a relatively expanded extracellular mass. An elective operation of moderate severity resulted in a 14% decrease in the body cell mass while the extracellular mass increased by 10%. The 4% postoperative decrease in body weight did not accurately reflect the change in the body cell mass. The efficacy of total parenteral nutrition (TPN) with lipid as the major caloric source was compared with TPN with hypertonic dextrose. With lipid a daily infusion of 44.2 Cal/kg (185 kJ/kg) was required to maintain the body cell mass while with the solution containing hypertonic dextrose 34.7 Cal/kg (155 kJ/kg) was required--a 27% difference. Total parenteral nutrition with hypertonic dextrose is therefore more efficacious than TPN with lipid as the major caloric source.

Amino Acids↗
PubMed1978

Nutritional requirements of anaerobic coryneforms.

The nutritional requirements of three species of anaerobic coryneforms and their serotypes (Propionibacterium acnes types I and II, P. avidum types I and II, and P. granulosum) were determined. Strains of P. avidum would consistently grow to a transmittance of 1 to 3% at 560 nm in a basal salts medium supplemented with glucose, pantothenate, biotin, thiamine, and 12 amino acids (alanine, arginine, cysteine, glutamine, glycine, histidine, isoleucine, methionine, phenylalanine, serine, tyrosine, and tryptophan). Strains of P. acnes and P. granulosum, however, failed to grow in this medium unless six additional amino acids were present (asparagine, leucine, lysine, proline, threonine, and valine). All three species grew equally well whether the 18 amino acids were supplied in the form of a casein hydrolysate supplemented with tryptophan or were added separately. Nicotinamide enhanced growth of P. acnes but had no effect on growth of P. avidum and P. granulosum. Other nutrients which were not absolute requirements, but which significantly improved growth of these species, included the purines guanine and/or adenine, Tween 80, which served as a source of oleic acid, sodium L-lactate, alpha-ketoglutarate, and pyruvate. Strains (86) comprising all five groups grew well in the defined medium, except four strains of P. acnes type II (29 tested), which failed to grow unless heme and vitamin K were added to the medium. One strain of P. granulosum (22 tested) failed to grow in any defined medium, suggesting an additional growth factor requirement.

Amino Acids↗
PubMed1964

NUTRITIONAL REQUIREMENTS OF LACTOBACILLUS 30A FOR GROWTH AND HISTIDINE DECARBOXYLASE PRODUCTION.

Guirard, Beverly M. (University of California, Berkeley), and Esmond E. Snell. Nutritional requirements of Lactobacillus 30a for growth and histidine decarboxylase production. J. Bacteriol. 87:370-376. 1964.-The nutritional requirements of Lactobacillus 30a include each of the naturally occurring amino acids, several B vitamins, ascorbic acid, glucose, acetate, and oleate. The nutritional requirements for optimal histidine decarboxylase production (up to 900 muliters of CO(2) per hr per mg of cells) differ to some extent from those for optimal growth. Wholly synthetic and partially defined media are described which produce high enzyme activity, together with rapid and luxuriant growth.

Amino Acids↗