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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Concept of labile protein and the adaptation of nitrogen metabolism in protein deficiency in man].

Investigations involving 30 healthy males, who for 45 days consumed standard semisynthetic diets differing in the caseine content (from 0 to 15.1 g of nitrogen per day) and serving as a sole source of protein, furnished data on the nitrogen excretion kinetics and nitrogen balance. Mathematical analysis of these data allowed it to find the existence of general regularity in the nitrogen excretion and to deduce an integral equation of its losses at different levels of nitrogen consumption. Pertinent calculations have ascertained that by the labile protein one should understand not the specific proportion of the total protein in the organism, but the actual rate of its metabolism, manifesting itself in the routine lag-phase during adaptation of the nitrogen metabolism to a new level of the protein allowances in the organism. The data thus made available permitted it, at the same time, to propose a criterion for estimating the optimal requirements of man in proteins.

Adaptation, Physiological↗
PubMed1975

Enniatin production by Fusarium sambucinum: primary, secondary, and unitary metabolism.

Fusarium sambucinum liquid surface cultures on semi-defined medium with glucose as carbon source passed through well-defined phases corresponding to trophophase, idiophase (enniatin production), and a degenerative phase. All the glucose was consumed by day 6, at which time the mycelial dry weight had reached only half its maximum. When glucose was replaced by lactose, there was no separation of trophophase and idiophase. Enniatin production, dry weight, and sugar and nitrogen consumption were in approximate balance throughout the growth period (25 days), after which slow degeneration began. The term 'unitary metabolism' is proposed for this type of unphased behaviour. Unitary metabolism may approximate more closely to that occurring under natural conditions than does the metabolic phase separation observed when rapidly utilized carbon sources are used in laboratory cultures.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Effect of ethanol adminstration in the consumption of proteins and nitrogen balance in normal subjects with normoprotein diet].

The effect of excessive alcohol intake on the protein requirements and metabolism in normal subjects has not been clearly determined. In this study we measured the nitrogen balance, the hematrocrit, the hemoglobin, the serum albumin, the cholesterol, and the plasmatic amino acids in 7 non-alcoholic subjects of 25 +/- 5 years of age. A comparison was made of a diet containing 0.8 g of protein per k of weight and 40 Kcal per k of weight administered during 11 days with a period of the same length in which the 1.400 Kcal provided during the control period by carbon hydrates was provided by ethanol (200 g). During the alcoholic period no importants changes were observed in the nitrogen balance, a tendency towards greater positivity being registered. There was a decrease in the serum albumin of 4, 69 +/- 0.31 vs 3, 90 +/- 0,32 g/100 ml and an increase in globulin 1,74 +/- 0,70 vs 2,69 +/- 0,22 g/100 ml. The results showed that in a short period of time the excessive alcohol intake in normal subjects does not increase the protein requirements in spite of a decrease in the serum albumin being observed.

Adult↗
PubMed1979

Nitrogen-fixing capacity of Azotobacter as affected by the type and depth of substrate.

Sixty isolates, representing the different types of azotobacters in Egyptian soils, were studied for their N2-fixing capacity. When A. chroococcum and A. vinelandii were grown in shallow layers of N-deficient liquid medium, nitrogen gains ranged from 48 to 92 and from 20 to 120 ppm with efficiencies of N2-fixation from 15.8 to 50.0 and from 16.6 to 21.2 mg N fixed/g C oxidized, respectively. Culturing in deep layers generally lowered the nitrogen gains and the oxidation of carbon, but at different rates, resulting in the increase of the efficiency of N2-fixation by 2--78%, indicating that the depth of the liquid medium has a definite effect on the outcome of N2-fixation. In another experiment, A. vinelandii was grown in increasing depths of liquid or solid substrates and consequently at variable ratios of surface area: depth. In liquid medium, maximum counts, sugar consumption, and nitrogen gains were detected in the widest surface area: depth ratio, but the efficiency of N2-fixation increased with the narrowing of the ratio. In sand cultures an opposite trend was observed.

Aerobiosis↗
PubMed2026

Human Milk Oligosaccharides Modulate Nitrogen Utilization in Lactobacillus crispatus in a Glucose-Dependent Manner.

The vaginal microbiome's transition to a dysbiotic state increases susceptibility to pathogens like group B Streptococcus. While human milk oligosaccharides are established prebiotics in the neonatal gut, their impact on the vaginal niche remains largely unexplored. This study investigated the effects of pooled human milk oligosaccharides on the growth and physiology of vaginal (Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners) and gut-derived (Lactobacillus reuteri, Lactobacillus rhamnosus) commensals. Growth analyses revealed that human milk oligosaccharides significantly and selectively stimulated growth across all vaginal strains tested, whereas gut commensals exhibited variable or inhibited growth. Carbohydrate utilization assays and comparative genomics against Bifidobacterium infantis showed that Lactobacillus crispatus and Lactobacillus reuteri lack the canonical metabolic machinery to catabolize human milk oligosaccharides. Instead, nitrogen utilization assays identified a glucose-dependent pathway where human milk oligosaccharides are associated with the depletion of primary amines and amino acids in Lactobacillus crispatus supernatants. These results suggest that human milk oligosaccharides act as noncatabolic modulators of vaginal lactobacilli. Collectively, these in vitro findings may warrant investigation of human milk oligosaccharides as modulators of vaginal commensal physiology in more complex experimental systems.

Humans↗
PubMed1978

Microbial fixation of nitrogen in presence of lanthanum sulphate with sodium molybdate.

The effect of lanthanum sulphate together with 100 micrometer of sodium molybdate show that there is considerable increase in nitrogen fixation and carbon consumption in the culture medium of nitrogen-fixing Azotobacter species A1 and A2, isolated from Allahabad soil. But these combination decrease the nitrogen fixation and carbon consumption in case of another species, Azotobacter A3, of the same soil.

Azotobacter↗
PubMed1979

Effect of deficiencies of single essential amino acids on nitrogen and energy utilisation in chicks.

1. Diets 50% deficient in single essential amino acids were fed to chicks from day 8 to day 18 after hatching to evaluate body-weight gain, food consumption, body composition, nitrogen (N) and energy utilisation. 2. Body-weight gain was reduced most severely by deficiency of isoleucine followed in decreasing order by threonine, arginine, valine, histidine, tryptophan, methionine plus cystine, phenylalanine plus tyrosine, leucine and lysine, and possible reasons for the differences are discussed. 3. Body-weight gain and food efficiency were highly correlated with food consumption but metabolisable energy value of diets was not affected by single essential amino acid deficiencies. 4. Generally N retention (N retained/N consumed) and energy retention (energy retained/energy consumed) reflected food consumption, except for a lower N retention by chicks fed on the methionine plus cystine-deficient diet and for a lower energy retention by chicks fed on the valine deficient diet. 5. The amino acid deficient in the diet was present at very low concentration in the blood plasma.

Amino Acids, Essential↗
PubMedDate not supplied

[Biosynthesis of citric and isocitric acids by the wild-type and mutant strains of Candida lipolytica in media containing different carbon sources].

Experiments were carried out to examine the capacity of two strains of Candida lipolytica, producing citric and isocitric acids in the alkane and glucose containing media, to grow on different two- and three-carbon compounds. The strains did not grow on oxalate, glyoxalate, glycolate, malonate or propionate. When cultivated in the media containing acetate, ethanol, glycerol, glucose or hexadecane, supersynthesis of the acids started after complete consumption of the nitrogen source and resultant delay of the culture growth. Either strain discharged the two acids in a proportion that depended on the strain nature and the type of the carbon source. The mutant strain produced only citrate while the wild-type synthesized both citrate and isocitrate, the ratio of which was related to the nature of the carbon source utilized.

Candida↗
PubMed1977

[Characteristics of fucidin biosynthesis by a Fusidium coccineum 257 A strain].

The physiological features of Fusidium coccineum, strain 257 A, an organism producing fusidin were studied. It was found that increased concentrations of the carbon sources in the medium stimulated production of fusidin, while an increase in the content of various forms of nitrogen differently affected the level of the antibiotic viosynthesis: high concentrations of the amino acid-peptide form of nitrogen of corn-steep liquor decreased, while the protein form of nitrogen was associated with consumption of the significant part of carbon in the medium for formation of the fungus mycelium. Therefore, the concentration of the easily mobilizing forms of nitrogen may be considered as a regulator of the growth process of F. coccineum 257 A and production of fusidin by it.

Carbohydrate Metabolism↗
PubMed1977

A comparison of the energy and nitrogen metabolism of broilers selected for increased growth rate, food consumption and conversion of food to gain.

Calorimetric measurements were made on 5-week-old male chickens sampled from the third generation of three lines selected for either increased live-weight gain (W), food consumption (F), or food conversion efficiency (E). A control line (C) was also measured. 2. Food intake and food conversion ratio were greater (P less than 0-05) in the F line than in the E anc C lines. 3. Metabolisability of the diet was 0-8% higher in the E line than in the other lines. 4. Metabolisable energy (ME) intake and heat production were greater (P less than 0-05) in the F line than in the E and C lines, and energy balance was greater (P less than 0-05) in the F than in the W and E lines. 5. During starvation, excreta energy and heat production were greater (P less than 0-05) in the F than the other lines. 6. Availability of ME (net energy) was the same (85%) for all lines but calculated daily maintenance energy requirements (kJ ME/kgW) were W, 860; F, 937; E, 796 and C, 810. 7. By 9 weeks the F line contained more fat and less water than lines E and C.

Animal Feed↗
PubMed1978

Metabolism, oxygen transport, and erythropoietin synthesis in the anemia of thermal injury.

The relationship between metabolism, oxygen transport, and anemia was assessed in burn patients. A significant negative correlation was found between erythrocyte 2,3 DPG, the major modulator of oxygen transport, and erythropoietin synthesis. Simultaneous bioassay and radioimmunoassay for erythropoietin revealed elevated values in the anemic burn patients. Elevated 2,3 DPG values during convalescence from thermal injury may remove the "anemic hypoxia" stimulus to erythropoieitn production, resulting in persistence of the anemia.

Adult↗
PubMed1978

Intestinal function in infants with severe congenital heart disease.

We evaluated digestive tract function in 21 young infants with severe congenital heart disease. One group had congestive heart failure and ventricular septal defect or single ventricle; the other had cyanosis and transposition of the great arteries. Enteric protein loss was excessive in eight patients, and steatorrhea was found in five. These abnormalities were mild and not related to the type or severity of the cardiac lesion. Available evidence points to a need of these babies for calories in excess of normal requirements for weight. The present study suggests that in designing dietary regimens for these very sick patients, their potential for defective gastrointestinal function must be considered. Because no consistent pattern of abnormalities in apparent, each patient who fails to thrive may deserve gastroenterologic evaluation.

Body Weight↗