Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “dietary environments”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2026

Genome-Wide Association Analysis for Growth-Related Traits in Indoor- and Outdoor-Cultured Juvenile Grass Carp (Ctenopharyngodon idella).

Grass carp is a key herbivorous freshwater fish, yet long-term inbreeding reduces growth rates. Current genome-wide association studies (GWAS) primarily focus on a limited range of growth traits, while intestinal morphology is likely to emerge as a promising new proxy for both growth performance and health status. We reared juvenile grass carp from one batch in indoor vs. natural aquatic vegetation groups for 100 days, measuring body weight (BW), length (BL), height (BH), and intestinal length (IL) in 200 individuals (100/group). Phenotypic differences were significant for all traits, with IL most variable. GWAS identified 95 significant SNPs, among which 21 were related to multiple traits. Candidate gene and KEGG pathway analyses linked these SNPs to myogenesis, skeletal development, immunity, calcium signaling, and stress resistance. Twelve SNPs were found to be associated with IL, including 8 multi-trait-related and 4 trait-specific ones. This suggests that IL can serve as a supplementary growth trait. There was no overlap with prior GWAS, but recurrent signals on chromosomes 1, 2, 14 (BW) and 2, 3, 14, 24 (BH) merit further study. Our findings enrich molecular resources for grass carp and highlight IL's potential for marker-assisted breeding.

Ctenopharyngodon idella↗
PubMed2026

Post-colonial human admixture and natural selection: disentangling signals in complex demographic contexts.

Natural selection and admixture are defining population genetic features of modern human populations, yet their interaction has only recently emerged as a major focus in human evolutionary genomics. While the influence of natural selection on population structure and trait diversity is well established, the ways in which selective pressures operate after admixture have historically received far less attention. In this review, we synthesise the latest progress in understanding post-admixture selection and highlight case studies that illustrate how novel environments, pathogen exposure, dietary shifts and socio-historical transformations have driven genomic adaptation. We conclude by identifying key gaps that remain in the field with the aim of motivating future research and facilitating new insights into how admixture and selection jointly shape human diversity.

Journal Article↗
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↗
PubMed1977

Diet, DDT, and the toxicity of drugs and chemicals.

The toxic and carcinogenic effects of many compounds depend on their activation to reactive molecules in the cytochrome P-450 system of the endoplasmic reticulum of cells. Changes in dietary input alter P-450 levels in different tissues and so alter toxicity. In this way, low protein diets protect against carbon tetrachloride poisoning. Fats, proteins, and nonnutrients such as flavones, antioxidants, and contaminants like DDT all affect P-450 levels. The activated molecules may be diverted from their target sites by inactivation processes, such as epoxide hydratase or glutathione trappin. This is also under nutritional control. Low protein diets render animals sensitive to acetaminophen by reducing glutathione levels. In the sequence of events leading from initial contact of toxin with organism to eventual cell injury or neoplasm, nutritional factors are of import at every stage. Assessments of the toxicity of chemicals that do not take into account the nutritional variable in man are likely to be incorrect.

Acetaminophen↗
PubMed1977

Two-stage control of cell proliferation induced in rat liver by alpha-hexachlorocyclohexane.

Determinants of the timing of DNA synthesis in rat liver were studied, using alpha-hexachlorocyclohexane as a tool for stimulation of cell proliferation. One determinant is the time of alpha-hexachlorocyclohexane administration. The increase in DNA synthesis starts after a lag phase (prereplicative phase) of minimally 20 hr. Use of animals adapted to a controlled feeding and lighting schedule revealed a second determinant provided by food consumption. Initiation of DNA synthesis is suppressed by fasting or protein deprivation and occurs 5 to 8 hr after readministration of a protein-containing diet. The light-dark rhythm has no direct influence on the timing of DNA synthesis. Stimulation of hepatic DNA synthesis, therefore appears to require two different sequential signals. The first is provided by alpha-hexachlorocyclohexane, and the second is provided by protein intake. In the absence of the second signal, committed cells are arrested at a critical point of the prereplicative phase and accumulate. Protein intake permits release from the block, and the accumulated cells enter the S period almost synchronously after completion of the remaining 5 to 8 hr of the prereplicative phase. These observations provide a means of synchronizing, in the living animal, a proliferating population of hepatocytes. In addition, they offer an explanation for the diurnal rhythmicity in the rate of hepatic cell proliferation.

Animals↗
PubMed2026

Divergent PXR function in seals: Endocrine adaptation or functional loss?

Seals accumulate xenobiotics through dietary biomagnification and exposure to polluted marine environments, with contaminants concentrating in their blubber. Biotransformation mitigates xenobiotic toxicity by converting lipophilic compounds into excretable hydrophilic metabolites, a process coordinated by nuclear receptors including the Pregnane X Receptor (PXR), whose plastic ligand-binding domain enables broad xenobiotic sensing. By examining PXR in pinnipeds, we investigated the evolutionary conservation and functional characterization of PXR using genomic sequence analysis, protein structural prediction, and transactivation assays, revealing broadly conserved structural features alongside species-specific functional divergence in receptor responsiveness to environmental stressors. Specifically, the obtained results highlight divergent gene and functional landscapes with ORF-disrupting mutations identified in Monachus monachus and Neomonachus schauinslandi that abolish receptor activation toward known PXR ligands. In contrast, Leptonychotes weddelli retained an intact PXR ORF but showed reduced receptor activity, revealing functional divergence in PXR among pinnipeds.

Biotransformation↗
PubMed2025

Enriched grain minerals in Aegilops tauschii-derived common wheat population under heat-stress environments.

In wheat (Triticum aestivum L.), an important source of dietary minerals, heat stress during the grain filling stage negatively affects grain yield and quality. Wheat grain mineral content has been primarily evaluated under optimum conditions; little information is available on the genetic variations and loci involved in mineral accumulation under heat stress. Therefore, this study aimed to assess the variation in 13-grain mineral concentrations and thousand kernel weight of 145 wheat multiple synthetic derivatives (MSD) genotypes harboring genes from the wild relative Aegilops tauschii Coss., evaluated under heat-stress field conditions in Sudan for two seasons, and to dissect the genomic regions associated with these mineral contents using GWAS. Our results showed sufficient variations in mineral concentrations among the MSD lines. Some MSD lines had 30-50% more minerals than the recurrent parent Norin 61. We detected 188 significant marker-trait associations (MTAs), 44 MTAs in season 2018/19, one in season 2019/20, and 143 based on BLUE. The highly significant, stable, and promising MTAs were related to Mg, Mn, P, and Ba. We identified putative candidate genes potentially involved in mineral movement (TraesCS5D03G0728800) and response to heat stress (TraesCS5D03G0723300). The findings in this study help to enhance mineral concentration and resilience in wheat under heat.

Triticum↗
PubMed1979

Simultaneous measurement of serum 25-hydroxycholecalciferol and 25-hydroxyergocalciferol.

A method for the selective measurement of serum 25-hydroxycholecalciferol and 25-hydroxyergocalciferol has been developed. The two hydroxysecosteroids were measured in a control group and in a group of ambulatory patients treated chronically with anticonvulsant drugs. In both groups the serum levels of 25-hydroxycholecalciferol and 25-hydroxyergocalciferol followed a log normal distribution. No significant difference could be elicited between the control and the treated groups for either hydroxysecosteroid. Furthermore the data shows how important is the dietary source of vitamin D in our environment.

Adolescent↗
PubMed2025

Interaction of genetics risk score and fatty acids quality indices on healthy and unhealthy obesity phenotype.

BACKGROUND: The growth in obesity and rates of abdominal obesity in developing countries is due to the dietary transition, meaning a shift from traditional, fiber-rich diets to Westernized diets high in processed foods, sugars, and unhealthy fats. Environmental changes, such as improving the quality of dietary fat consumed, may be useful in preventing or mitigating the obesity or unhealthy obesity phenotype in individuals with a genetic predisposition, although this has not yet been confirmed. Therefore, in this study, we investigated how dietary fat quality indices with metabolically healthy obesity (MHO) or metabolically unhealthy obesity (MUO) based on the Karelis criterion interact with genetic susceptibility in Iranian female adults. METHODS: In the current cross-sectional study, 279 women with overweight or obesity participated. Dietary intake was assessed using a 147-item food frequency questionnaire and dietary fat quality was assessed using the cholesterol-saturated fat index (CSI) and the ratio of omega-6/omega-3 (N6/N3) essential fatty acids. Three single nucleotide polymorphisms-MC4R (rs17782313), CAV-1 (rs3807992), and Cry-1(rs2287161) were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique and were combined to produce the genetic risk score (GRS). Body composition was evaluated using a multi-frequency bioelectrical impedance analyzer. Participants were divided into MHO or MUO phenotypes after the metabolic risk assessment based on the Karelis criteria. RESULTS: We found significant interactions between GRS and N6/N3 in the adjusted model controlling for confounding factors (age, body mass index, energy, and physical activity) (β = 2.26, 95% CI: 0.008 to 4.52, P = 0.049). In addition, we discovered marginally significant interactions between GRS and N6/N3 in crude (β = 1.92, 95% CI: -0.06 to 3.91, P = 0.058) and adjusted (age and energy) (β = 2.00, 95% CI: -0.05 to 4.05, P = 0.057) models on the MUH obesity phenotype. However, no significant interactions between GRS and CSI were shown in both crude and adjusted models. CONCLUSION: This study highlights the importance of personalized nutrition and recommends further study of widely varying fat intake based on the findings on gene-N6/N3 PUFA interactions.

Humans↗
PubMed1977

Riboflavin requirement of starting chickens in a tropical environment.

Growth rate of broiler chicks tends to be lower in the tropics than in the temperate zone. Results show that up to 17% of dietary riboflavin is destroyed within 24 hours of exposure of the feed to light hence the level of 3.6 mg. of vitamin B2 recommended does not meet the requirement for growth of broilers. Growth study as well as accumulation of riboflavin in meat and organs of the birds showed that increasing levels of dietary riboflavin increases its deposition in meat and organs of the birds. Optimum growth of birds and storage of riboflavin in the body is attained in the tropical environment when 5.1 mg. of the vitamin is added per kg. of practical ration.

Animals↗
PubMed1979

Alteration of catecholamine uptake in cerebral cortex from rats fed a saturated fat diet.

The transport of [3H]norepinephrine into chopped cerebral cortex of neonates was changed by feeding pregnant rats with semisynthetic diets enriched in saturated fat (coconut oil) as compared to polyunsaturated fat (sunflower oil). There was a significant decrease in the uptake of norepinephrine in neonates from dams fed coconut oil compared to neonatal pups from animals fed sunflower oil. Differences were observed on days 7, 11, 24, and 37 but not in adults which had been maintained on the diet since birth. Kinetic analysis of norepinephrine uptake on day 7 neonates demonstrated a 5-fold increase in Km and a 2-fold increase in Vmax for the coconut oil fed group as compared to control or the sunflower oil fed rats. [3H]Dopamine uptake kinetics revealed no significant difference in day 7 neonates but a doubling of the Km and Vmax in day 37 rats and in adults fed coconut oil. Lipid analysis of cerebral cortex synaptosome membrane fractions revealed significant differences in the fatty acyl composition of the phospholipid. The results indicate that the norepinephrine and dopamine transport systems can be differentially affected by dietary lipid composition in the developing rat. It is suggested that the changes may be due to alterations in membrane fluidity in the local environment of the transport system.

Animal Feed↗
PubMed1977

[Epidemiology of cancer and the environment].

Results of epidemiological investigations point out that environmental factors have an influence on the development of at least 80% of cancer diseases. The cancer mortality rates in Austria are analyzed with regard to this point. Austrian mortality trends of the most common malignancies are similar to those of other western industrialized countries. The relationship between cancer risk and the size of the Austrian communities is shown. As opposed to other common cancer sites, cancer of the stomach is most common in small communities with mainly an agricultural population. Etiological hypotheses about the origin of stomach cancer are discussed with regard to its epidemiological findings as well as the dietary habits of the population.

Adult↗
PubMed1977

Nutrition analysis of prosthodontic patients.

A program of nutrition training has been included in the undergraduate curriculum of the University of Washington School of Dentistry. Data obtained indicated that involved patients were receptive and that many showed improvement in dietary habits. Nutritional analysis and counseling can be introduced into a private-practice environment with very little increase in the dentist's work time. Procedures have been suggested that are efficient and effective. It is recommended that nutritional analysis and counseling be used routinely on all prosthodontic patients. This training should be included in the dental school curriculum so that students can become competent and comfortable in its use. To meet this objective, in-service training programs for faculty members are required. Careful attention to systemic factors such as nutrition will allow dentists to provide an enhanced level of care for patients. Concern for the general health of patients must continue to be a necessary part of prosthodontic care.

Cooperative Behavior↗