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At least 19 recordsLinked to original sources
PubMed1978

Surface colony growth in a controlled nutrient environment. 3. Dependence of growth constant on nutrient concentration.

The growth rates of yeast surface colonies under constant nutrient conditions were studied as a function of nutrient concentration. This was complementary to the initial experiment to measure the rates under such conditions, and to the investigation of the effects of alcohol. The possibility of fitting an equation of the Michaelis-Menten type to the variation of growth rate with carbon source concentration is considered.

Culture Media↗
PubMed1979

[Possibilities of prediction the digestibility of crude nutrients by fullgrown and growing sheep from the crude nutrient content of the rations. 2. Rations with a higher content of crude fibers (mixtures of straw and concentrated feed as sole feed].

Eight variants of recipes for mixtures of straw and concentrated feed with 10 to 60 per cent straw more or less finely ground (86 to 314 g crude fibre per kg dry matter) and fattening feed for lambs (50 g crude fibre per kg dry matter) were checked concerning the digestibility of crude nutrients for fullgrown wethers and 60 to 80-, 80 to 100-and 100 to 120-day-old lambs which had been ablactated at an age of 60 days. The digestibility for wethers was significantly higher than for lambs, between the age groups of which there were no significant differences concerning the digestibility. In accordance with the results with rations on the basis of concentrated feed as checked and described in the first piece of information, the content of crude fibres in the rations had a negative influence on the digestibility of organic matter, NFE and energy whereas there was a positive relation with the digestibility of crude fibres. The regression functions established for mixtures of straw and concentrated feed concerning the dependence of the digestibility on the content of crude fibres showed a relatively good coincidence in the range of a low content of crude fibres with the corresponding regression functions which were described in the first piece of information for rations of concentrated feed. The equations for the digestibility of crude fibres were an exception. In contrast to this, the quantitative relations between crude fibres and the digestibility as established in the first piece of information for rations with a low content of crude fibres cannot be transferred to rations with a higher content of crude fibres.

Animal Feed↗
PubMed1979

Nutrient analysis of Exchange Lists for Meal Planning. I. Variation in nutrient levels.

Using available food composition data, individual Exchange Lists within the revised Exchange Lists for Meal Planning were evaluated for calories; protein; fat; calcium; phosphorus; iron; sodium; potassium; vitamin A; thiamin; riboflavin; niacin; ascorbic acid; saturated, oleic, and linoleic fatty acids; cholesterol; and crude fiber. Mean values, standard deviations, and ranges are reported for the above nutrients. Mean values agreed well with those suggested in the booklet for grams of carbohydrates, protein, and fat and for calories for all lists except milk. However, a wide range in values exists for food within each Exchange List.

Diet↗
PubMed1979

Lanthanide markers in a single sample for nutrient studies in humans.

Multiple Lanthanide markers were used to develop procedures for determinations of intake and apparent utilization of four nutrients using data from fecal analysis and known concentrations of markers in nutrients. Terbium oxide was given as the intake marker. All foods contained the other non-absorbed markers, each marker in direct proportion to the amount of a specific nutrient in each food. Nutrient markers were oxides of samarium, scandium, ytterbium, and europium. Fecal collection and subsequent analysis of nutrients and markers were completed. Fecal marker concentration stabilized 2 days following initiation of the marker regime. Thus, after 3 days, a single grab sample could be utilized to analyze for nutrient utilization. The ratio of nutrient marker proportional to nutrient and intake to nutrient excretion provides the data for the calculation of apparent utilization for as many nutrients as nutrient markers incorporated into the food. When direct and marker methods of determining nutrient intake and apparent utilization were compared, no significant differences were found for gross energy, fat, protein, and calcium.

Adult↗
PubMed1976

Growth of Enterobacter aerogenes in a chemostat with double nutrient limitations.

The behavior of Enterobacter aerogenes during growth in chemostats limited by single and double nutrient restrictions was examined. On the assumption that different essential nutrients act to limit growth in different ways, we selected pairs of nutrients likely to affect different aspects of metabolism. Results show that macromolecular cell composition can be controlled by using more than one nutrient restriction. The polysaccharide content of the cells is readily manipulated by the ratio of carbon to nitrogen in the inlet nutrients. Also, at low dilution rates, ratios of protein to ribonucleic acid are dependent on the ratio of phosphate to nitrogen in the input nutrients. An examination of both acetic acid and metabolite production (as measured by ultraviolet absorbance of culture filtrates) showed that accumulation of these products was dependent on both dilution rate and type of nutrient limitation(s). These results were examined in terms of the problems of translation of batch to continuous culture processes and the use of selected nutrient limitations to control noncellular product formation.

Ammonia↗
PubMed1977

Development of food tables and use with computers. Review of nutrient data bases.

Numerous tables of food composition have been compiled since the 1890s to meet the needs for nutrient data by nutritionists, researchers, and consumers. Early tables included values for protein, fat, carbohydrate, and calories. By 1945, values for several vitamins and minerals were listed in tables of food composition. The contents of food composition tables have been updated and expanded as laboratory procedures for analyzing nutrients have been improved. A trend toward increased specificity for most nutrient classifications has resulted in consideration of up to one hundred nutritional components in the development of nutrient data bases. Tables of food composition have varied in number of food items, number of nutrients, and classification schemes. Food-group designations have been used in some tables as a technique to categorize data for similar food items. Computer-stored nutrient data bases tend to vary in much the same manner as printed tables of food composition. Computer-assisted diagnostic procedures for editing input data for validity and verifying reasonable relationships among nutrient data have been developed to detect data inconsistencies. As data for new food products are included and the effects of food processing methods are determined, food composition tables and computer-stored nutrient data bases are expected to become more comprehensive, reliable, and suitable for various uses.

Calorimetry↗
PubMed1978

Density-dependent regulation of growth of BSC-1 cells in cell culture: control of growth by low molecular weight nutrients.

BSC-1 cells, epithelial cells of African green monkey kidney origin, show pronounced density-dependent regulation of growth in cell culture. Growth of the cells is rapid to a density of approximately 1.5 x 10(5) cells/per cm(2) in Dulbecco-modified Eagle's medium supplemented with 10% calf serum. Above this "saturation density," growth is much slower. It has been found that the glucose concentration in the culture medium is important in determining the "saturation density." If the glucose concentration is increased 4-fold, the "saturation density" increases approximately 50%. Reduction of the "saturation density" of BSC-1 cells is also possible by decreasing the concentrations of low molecular weight nutrients in the culture medium. In medium supplemented with 0.1% calf serum, decreasing the concentrations of all of the organic constituents of the medium, from the high levels present in Dulbecco-modified Eagle's medium to concentrations near physiological levels, decreases the "saturation density" by approximately half. The decreased "saturation density" is not the result of lowering the concentration of any single nutrient but rather results from reduction of the concentrations of several nutrients. When the growth of BSC-1 cells is limited by low concentrations of all of the nutrients, some stimulation of growth results from increasing, separately, the concentrations of individual groups of nutrients, but the best growth stimulation is obtained by increasing the concentrations of all of the nutrients. The "wound healing" phenomenon, one manifestation of density-dependent regulation of growth in cell culture, is abolished by lowering the concentration of glutamine in the medium. Density-dependent regulation of growth of BSC-1 cells in cell culture thus appears to be a complex phenomenon that involves an interaction of nutrient concentrations with other regulatory factors.

Biological Transport↗
PubMed1979

Genetic and biological variability in human nutrient requirements.

Multiple factors, associated with the host and environment, as well as the chemical form of the nutrient, its availability, chemical and metabolic interactions among nutrients, result in a variability in nutrient requirements that is probably well beyond that observed in controlled laboratory studies of small groups of "normal" healthy subjects. Although many factors are recognized as contributing to the variation in human nutrient requirements, current knowledge is largely of qualitative significance: Garn (40) state that this level of knowledge and investigation "has a long past but no foreseeable future." It is sad commentary that neither do we know adequately the quantitative extent of biological variation in requirements among individuals for any of the essential nutrients nor the quantitative importance of most of the factors which affect requirements in population groups. We believe that the potential contributions of nutrition toward solving problems of human disease and for maintaining health in populations depend as much on a better definition of the quantitative aspects of human nutrient requirements as on improved understanding of the utilization, function and metabolism of nutrients at the cellular, organ, and whole body level.

Adult↗
PubMed2025

Multi-omics reveals an ecdysone-activated Eip75B-FABP signaling axis coordinating nutrient metabolism for development in Hermetia illucens.

INTRODUCTION: Efficient nutrient storage is essential for insect development and energy homeostasis; however, the mechanisms coordinating nutrient allocation during ontogeny are not well understood. Elucidating these systems may yield valuable insights to insect metabolic adaptation. OBJECTIVES: This study aimed to identify regulatory modules governing nutrient metabolism in insects, focusing on hormonal and metabolic interplay. METHODS: Multi-omics profiling (proteomics, phosphoproteomics, and transcriptomics) was conducted throughout the life cycle, from egg to adult, to identify metabolic regulators. RNAi was utilized for gene knockdown, followed by qRT-PCR and mitochondrial DNA quantification to evaluate knockdown efficiency and its metabolic implications. Assessments of nutrient metabolism were performed using assays for triglycerides, crude protein, and fatty acid synthase. EMSA and BODIPY staining examined transcriptional regulation and lipid droplet dynamics. RESULTS: Utilizing an integrative multi-omics approach, this study elucidates the temporal metabolic regulators in insects. A conserved regulatory module was identified in which the PPAR homolog, ecdysone-induced protein 75B (Eip75B), functions as a transcriptional activator of fatty acid binding protein (FABP), sustaining lipid metabolic homeostasis during the larval stage. PPARγ modulators (rosiglitazone and GW9662) alter lipid accumulation, along with the expression of Eip75B and FABP, which was measured by qRT-PCR. Furthermore, the deficiency of FABP may reprogram metabolic pathways by inhibiting lipid storage and promoting mitochondrial β-oxidation, as supported by increased mitochondrial DNA copy number, as well as enhancing protein synthesis. This metabolic change could be modulated by ecdysone signaling, as hormonal supplementation effectively rescued the lipid loss phenotype. Our results establish the ecdysone-Eip75B-FABP signaling axis as a central regulatory module that integrates hormonal and nutrient-sensing signals to control insect nutritional metabolism. CONCLUSION: The ecdysone-Eip75B-FABP axis integrates hormonal and nutrient signals to regulate metabolic plasticity, underscoring a universal strategy for developmental energy allocation. The data also offer potential implications for research on metabolic disorders and bioenergy applications.

Animals↗
PubMed2025

Balancing nutrient remobilization and photosynthesis: proteomic insights into the dual role of lupin cotyledons after germination.

Efficient nutrient mobilization from seed storage tissues is essential for seedling establishment, particularly in legumes such as Lupinus albus (white lupin), which thrive in nutrient-poor soils. This study investigates the role of cotyledons in nitrogen (N) and mineral remobilization after germination during their transition from storage organs to photosynthetically active tissues, including the metabolic challenges posed by the coexistence of these two functions in epigeal germination. We cultivated white lupin seedlings under nitrogen-deficient conditions, analyzing cotyledon composition and function over 28 days. Our results indicate that 60% of cotyledon-stored proteins are degraded within the first 8 days, with free amino acids transiently accumulating before being redistributed to support growth. The progressive depletion of cotyledon reserves was accompanied by structural and metabolic changes, including an increase in photosynthetic proteins. However, cotyledon photosynthetic capacity remained lower than that of true leaves, suggesting a transient role in energy metabolism. The loss of cotyledons before day 12 significantly impaired seedling development, emphasizing their critical contribution to nitrogen, phosphate, and micronutrient supply during early growth. Comparative proteomic analysis revealed dynamic shifts in nutrient transport, amino acid metabolism, and stress response pathways following cotyledon removal. These findings underscore the significance of cotyledon nutrient remobilization in legume adaptation to low-fertility soils and highlight potential targets for breeding strategies aimed at improving nutrient use efficiency. By optimizing cotyledon nutrient composition and function, future breeding efforts could enhance seedling vigor, reduce fertilizer dependency, and improve the nutritional value of lupin-based foods.

Lupinus↗
PubMed1979

Control of the Balb/c-3T3 cell cycle by nutrients and serum factors: analysis using platelet-derived growth factor and platelet-poor plasma.

Much controversy regarding the relationship between nutrients and serum in regulation of cell growth can be reconciled by recognizing that serum contains multiple factors which regulate different events in the cell cycle. Serum was fractionated into a platelet-derived growth factor (PDGF), which induces cells to become competent to synthesize DNA, and plasma which allows competent cells to traverse G0/G1 and enter the S phase. Nutrients are not required for the cellular response to PDGF; however amino acids are required for plasma to promote the entry of PDGF-treated, competent cells into S phase. The nutrient independent, PDGF-modulated, growth regulatory event (competence) is located 12 hours prior to the G1/S phase boundary in quiescent, density-arrested Balb/c-3T3 cells. The nutrient dependent, plasma-modulated event is located six hours prior to the G1/S phase boundary and corresponds in concentration of amino acids required for DNA synthesis. Infection of density-arrested Balb/c3T3 cells with SV40 overrides both the nutrient independent and the nutrient dependent growth regulatory events.

Animals↗
PubMed1979

Nutrient intake of low-income, black families in southwestern Mississippi.

A dietary intake study for 250 low-income households in Claiborne County in southwestern Mississippi was conducted from June through August 1974. Data were obtained during daily home visits for seven days by trained college students. The adequacy of nutrient intake for individuals was evaluated by comparing the data with the 1974 Recommended Dietary Allowances by age and sex. The data was also compared with those of the Ten-State Nutrition Survey and HANES. Mean intakes of protein, vitamin A, thiamin, riboflavin, and ascorbic acid for all subjects were above the RDAS; those of energy, calcium, iron, and preformed niacin were below the allowances. Whereas calcium was the nutrient least adequately consumed by all persons, protein was most adequately consumed. Sixty per cent of children had calcium intakes below two-thirds of the allowance. By sex, 66.7 per cent of all males and 73.3 per cent of all females had calcium intakes below two-thirds of the standard. None of children received less than two-thirds of the allowance for protein. Nutrient intake was low for a substantial number of the subjects. Adolescents, ages eleven to eighteen years, of both sexes had the poorest diets for all nutrients. Regarding the sex difference, females had better nutrient intakes than did males for all nutrients except calcium and iron.

Adolescent↗
PubMed1978

New methods for comparing the biological efficiency of alternate nutrient sources.

The objective of this study is to propose new methods for the determination of biological efficiency (the ability of a nutrient to produce a response) and for comparison of the efficiencies of alternate nutrient sources. The proposed methods are based on a four-parameter kinetic model which describes response as a function of intake. The comparison of the abilities of two proteins (casein and soybean protein concentrate) to promote weight gain in weanling rats is presented as an example; however, the model is also useful for other nutrients (proteins, amino acids, vitamins, minerals, etc.) and other responses (blood enzyme or protein levels, tissue enzyme levels, etc.). Application of the method leads to useful comparisons of nutrient sources as well as information concerning the maximum efficiencies and rates of nutrient utilization from different sources.

Animals↗
PubMed1978

Nutrient comparison of fresh and field-dried, green-seeded soybeans.

Nutrient composition and biologic utilization of cooked, dried, and ground meals prepared from fresh and field-dried, green-seeded edible soybeans were evaluated. On a dry-weight basis, nutrient content of the fresh and field-dried meals were comparable for protein, fat, calcium, phosphorus, magnesium, copper, and iron; fresh beans tended to have higher zinc content than the field-dried beans. Nutrient values for the green-seeded soybean meals were comparable to published values for full-fat soybean flour. Bioassay results indicated that protein efficiency ratios (PER) for rats fed casein were significantly better than those for the soybean-fed animals. Fresh, green-seeded soybean meal supported significantly better growth than did the field-dried, green-seeded soybean meal. Though significantly lower than that for the reference casein diet, the mean PER for fresh, green-seeded soybean meal was 90 per cent of that obtained with the reference casein. The nutrient analysis and protein bioassay data both indicate that green-seeded soybeans used as a vegetable item in the diet are a potentially significant food source of several important nutrients.

Animals↗
PubMed1977

Impact of fast food meals on nutrient intake of two groups.

Two groups in different population centers were studied to determine how often consumers frequented fast food restaurants, and consequently, how heavily they relied on this type of food for nutrients. A questionnaire was answered by 280 customers of two fast food restaurants of the same chain. They were asked how often they patronized fast food restaurants, their specific food choices, and other pertinent questions. Food choices were evaluated for energy and seven nutrients on the basis of published analyses of the menu items of the particular fast food chain. Fifty-two per cent of the subjects in the two groups considered their purchases to be meals. Seventy-seven per cent of these consumed one-third or more of the recommended dietary allowance for protein, but no more than 30 per cent received that amount of the other nutrients examined, including food energy. Calcium and particularly vitamin A were least often consumed in amounts equal to one-third of the recommended allowances. Consumer choices were responsible for low consumption of calcium, but no good sources of vitamin A were included on the menus. Fast food items were purchased so infrequently by the majority of our respondents that nutrient composition of the fast food meals or snacks would be of concern in only a small number of cases. This study indicates that any attempts to improve nutritive value of fast food snacks or meals must include efforts to lead consumers to make wiser food choices, as well as encourage the fast food industry to provide rich sources of all the nutrients in their menus.

Adolescent↗