Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “heterogeneous aging”

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 37 records · Page 2Linked to original sources
PubMed1979

Hemopoietic stem cell heterogeneity: use of cell cycle-specific drugs to look for age-associated alterations.

Hemopoietic tissue is vulnerable to perturbations, and data show that it is an appropriate tissue in which to look for age-associated alterations. This tissue has a high regenerative capacity, is composed of a heterogeneous population of stem cells that are capable of self renewal or differentiation, or both, and is sustained by a pool of resting cells. The heterogeneity of bone marrow has made characterization of the cellular elements difficult. Techniques commonly used to identify and quantify the various maturation levels of hemopoietic stem cells and the limitations of these techniques are discussed. Most techniques used to assay age-associated changes in bone marrow have not differentiated between specific cellular alterations or shifts in the distribution of the cellular elements. In particular, it has been difficult to determine the stability of the non-dividing stem cell because of the low incidence of this cell (6 per 1000) and the lack of a specific assay for this important cell type. The use of cell cycle-specific drugs has provided quantitative information on specific subpopulations of hemopoietic stem cells and seems to be the most promising approach towards determining qualitative and quantitative differences in the hemopoietic stem cells of young and old individuals.

Aging↗
PubMed1979

The effect of aging on carbohydrate metabolism: a review of the English literature and a practical approach to the diagnosis of diabetes mellitus in the elderly.

There seems little doubt that the disposal of a glucose load is progressively impaired during aging. The mechanism(s) for this alteration remains unclear. Five possibilities have been raised: (1) poor diet, (2) physical inactivity, (3) decreased lean body mass in which to store the carbohydrate load, (4) decreased insulin secretion, and (5) insulin antagonism. Although poor diet and physical inactivity may contribute to some of the abnormal glucose tolerance tests of the older population, these two factors do not provide a full explanation. Diminished lean body mass may play some role but there is almost certainly an additional effect due to aging. A few papers have suggested that glucose-induced insulin secretion may be impaired as the population ages, but the bulk of studies in this area conclude that normal or increased amounts of insulin are released by the pancreatic beta-cell during aging. If abnormalities of insulin secretion exist, either in degree or timing, they are subtle and would not seem sufficient to account for the great number of older subjects who manifest impaired glucose tolerance. The evidence for insulin antagonism seems the strongest but the data are certainly not conclusive. In actuality, the aging effect on carbohydrate metabolism may be heterogeneous in nature. Either some or all of these five factors may contribute to the aging effect to varying degrees in individual subjects. Alternatively, the glucose intolerance of aging may represent a heterogeneous group of disorders. In any event, until better methods to identify possible subgroups of these subjects and/or a marker for diabetes mellitus independent of glucose concentration become available, this problem will remain difficult to resolve. Based on the currently available data, it seems prudent to diagnose diabetes mellitus only if fasting hyperglycemia is present.

Aged↗
PubMed1978

Heterogeneity of human whole blood platelet subpopulations. II. Use of a subhuman primate model to analyze the relationship between density and platelet age.

A subhuman primate model was developed to ascertain whether or not platelet heterogeneity could be explained by aging in the peripheral circulation. Density-dependent platelet cohorts, postulated to represent cells of different ages, were isolated on isosmolar arabinogalactan gradients and labeled with radiochromium. Mean platelet lifespan was measured for the different density cohorts, and simultaneous sequential density distribution analysis was performed to follow changes in cell density during aging. The average mean lifespan of light platelets was 74.6 hr, compared to 313.6 hr for heavy platelets. After injection, labeled light platelets were recovered only in the gradient light region, in contrast to labeled heavy platelets, which were initially restricted to the dense region and progressively migrated to the light region during their lifespan. This study supports the hypothesis that platelet age in unstressed primates correlates with cell density and provides a rationale for the use of "age-dependent" markers to estimate platelet turnover rates.

Animals↗
PubMed1978

Quantification of intrauterine malnutrition.

Small-for-gestational-age infants are a heterogeneous collection of growth-retarded infants. In the subgroup of intrauterine-malnourished infants an attempt is made to quantify the degree of malnutrition by postnatal measurements of length, weight and fat-fold thickness. In 48 clinically wasted and not-wasted term newborns, regardless of birth weight, the ponderal index of Rohrer (100 X W/L3) was determined and the deviation from 'normal' calculated. The deviations are correlated with fat-fold thickness and clinical diagnosis. A highly significant correlation gives support to the view that both ponderal index deviation from 'normal' and fat-fold thickness are useful parameters to quantify the effect of intrauterine malnutrition in newborns.

Birth Weight↗
PubMed1979

Platelet heterogeneity. Relationship between buoyant density, size, lipid peroxidation and platelet age.

Human platelets were separated into 2 density populations by repeated centrifugations of platelet-rich plasma at increasing gravitational force. The heaviest platelet fraction was rich in larger platelets. The lightest platelet fraction was rich in smaller platelets. In both fractions and in the platelet button, lipid peroxidation (malonaldehyde-MDA-production after addition of thrombin) was measured at basal condition, on the 1st, 3rd, 5th, 7th and 9th day after aspirin ingestion. At basal conditions and after ingestion of aspirin, MDA production was higher in the heavy-large platelets than in light-small ones, but a parallel increase of MDA production was observed in the light and in the heavy population and in the platelet button. The data are not compatible with the hypothesis that platelet density and size are age-related. Aspirin inhibits platelet lipid peroxidation by permanently acetylating their cyclooxygenase and if the heaviest platelets were the young ones, lipid peroxidation should reappear sooner in them.

Aspirin↗
PubMed2026

Protective TMEM106B-rs3173615 delays age at onset in GRN mutation carriers.

One of the major causative genes involved in Frontotemporal dementia (FTD) is Granulin (GRN), encoding for Progranulin (PGRN). GRN mutation carriers show a substantial heterogeneity with high variability in age at onset and pathological presentation, even within the same family or identical mutations, suggesting the presence of additional genetic factors. Single nucleotide polymorphisms in the Transmembrane protein 106B (TMEM106B) locus were identified as a genetic risk-associated factor for FTD. The top variant identified was the non-coding rs1990622, with the major allele (T) associated with an increased risk to develop FTD, while subjects with the minor allele (C) were less likely to develop disease, suggesting a protective effect. In this study, we investigate in a large Italian cohort of GRN mutation carriers, how the coding variant TMEM106B-rs3173615, in linkage disequilibrium with rs1990622, modulates age at onset, survival, and PGRN levels, including, up to date, the highest sample size of homozygous protective allele carriers. Genetic screening for TMEM106B-rs3173615 was performed on a total of 187 GRN mutation carriers, comprising 131 FTD patients and 56 pre-symptomatic subjects. Individuals with the protective genotype (GG) had a risk of FTD onset reduced by 80%, with a median age at onset of 77 years compared to a median age at onset of 63 years for individuals without the protective genotype. TMEM106B-rs3173615 acts as a genetic modifier of age at onset in the presence of GRN mutations and could be considered in clinical practice to optimize risk stratification for FTD.

Humans↗
PubMed1977

Patterns of the use of benzodiazepines in Australia.

In six suburban areas of Sydney, chosen to provide a socioeconomic cross-section of the city, complete records of dispensing of benzodiazepine were collected over a four-week period. These drugs constituted 3.7% of all dispensing, female patients outnumbered males by 2.3:1, and 98% of patients were over 20 years of age. The predominance of females, and higher age groups was found in all the areas studied, but no socioeconomic correlation was detected in the use of the drugs. Analysis of national dispensing figures confirmed the higher consumption in higher age groups, and revealed no heterogeneity in per capita prescribing rates amongst the States.

Adolescent↗
PubMed2025

Deciphering Clonal Hematopoiesis of Indeterminate Potential: Methods, Mechanisms, and Implications for Kidney Diseases.

CKD afflicts over 10% of US adults, with its prevalence increasing sharply with age. Clonal hematopoiesis of indeterminate potential (CHIP) is a common, genetically heterogeneous blood cell disorder characterized by the age-related clonal expansion of hematopoietic cells driven by leukemogenic somatic mutations yet without hematologic malignancy or dysplasia. While CHIP is a strong risk factor of future hematologic malignancy (estimated at approximately 0.5% per year, compared with <0.1% for those without CHIP), it is also linked to two-fold higher cardiovascular disease in epidemiologic, cell-based, and murine studies. However, more recent work has implicated CHIP with kidney outcomes, such as CKD as well as AKI, independent of traditional risk factors. This review covers the observations and proposed hypotheses linking CHIP and kidney disease. The review also underscores the need for further research to elucidate the distinct pathways through which CHIP may contribute to CKD and its comorbidities, considering the heterogeneity within CKD stages and etiologies, as well as whether CHIP is a causal driver of kidney disease or a marker of aging and comorbidity. Finally, we discuss the potential of anti-inflammatory treatments to mitigate CHIP's adverse effects on kidney health, aiming to improve management strategies for patients with CHIP-associated kidney diseases.

Humans↗
PubMed2026

Ancient DNA unveils distinctive ancestries in the Bronze and Iron Ages of East Tianshan.

The East Tianshan Mountains occupy a key corridor between Central and East Asia, but their population history remains poorly understood. Here we report genome-wide data from 135 ancient individuals from 11 archaeological sites. We identify a previously unrecognized Bronze Age admixture between populations related to Yellow River millet farmers and steppe pastoralists associated with the Chemurchek culture. In contrast, we find little genetic contribution from contemporaneous middle-to-late Bronze Age steppe pastoralists, despite their eastward expansion across the Eurasian Steppe. By the Iron Age, regional populations had become more heterogeneous, incorporating additional eastern and steppe-related sources while retaining variable contributions from Early Bronze Age groups. These results reveal sustained demographic interactions in eastern Central Asia nearly 1800 years preceding the establishment of the historic Silk Road.

DNA, Ancient↗
PubMed1977

The 5'-termini of heterogeneous nuclear RNA: a comparison among molecules of different sizes and ages.

The composition of the 5' polyphosphorylated and capped termini of pulse labeled hnRNA from mouse L cells was analyzed by two-dimensional electrophoresis. Purine tri- and diphosphates: pppG, pppA, ppG and ppA; as well as four varieties of cap structure: m7GpppXm, Xm = Gm, (m6) Am, Cm and Um, were detected. With increasing labeling time the relative proportion of hnRNA molecules with tri- and diphosphorylated 5' ends decreases and the relative proportion of capped hnRNA increases, indicating that caps are metabolically more stable than the polyphosphate termini. About half of the hnRNA molecules that are labeled within 2 hr have capped ends. This finding, together with results of earlier kinetic and structural studies, implies that a relatively high proportion of the labeled hnRNA molecules are mRNA precursors. Large hnRNA molecules exhibit a higher proportion of capped ends and a lower proportion of 5'-triphosphate ends as compared to small hnRNA. Given the lower stability of triphosphate termini relative to caps, this result may mean that capping of some hnRNA molecules can occur before the completion of transcription.

Base Sequence↗
PubMed2025

Heterogeneity of Apolipoprotein B Levels Among Hispanic or Latino Individuals Residing in the US.

IMPORTANCE: Apolipoprotein B (apoB) distribution and its implications as an atherosclerotic cardiovascular disease (ASCVD) risk-enhancing factor among individuals of diverse Hispanic or Latino backgrounds have not been described. OBJECTIVE: To describe the distribution of apoB in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) cohort and to characterize associations of baseline sociodemographic and clinical variables with apoB and self-identified Hispanic or Latino background. DESIGN, SETTING, AND PARTICIPANTS: The HCHS/SOL was a prospective, population-based cohort study of diverse Hispanic or Latino adults living in the US who were recruited and screened between March 2008 and June 2011. Sampling weights were used to generate a population-based sample of Hispanic or Latino participants aged 18 to 74 years who resided in 4 US metropolitan areas (Bronx, New York; Chicago, Illinois; Miami, Florida; and San Diego, California). ApoB concentration was measured in participants from the HCHS/SOL, and apoB tertiles were compared across demographic groups, including self-identified Hispanic or Latino background. Median percentage continental genetic ancestry (West African, Amerindian, and European) was compared across apoB tertiles. EXPOSURE: ApoB measured in mg/dL from serum or plasma using an immunoturbidimetric assay. MAIN OUTCOMES AND MEASURES: ApoB tertiles were determined, and traditional lipids were evaluated across apoB tertiles. ApoB and traditional lipid measurements were assessed across ASCVD risk categories. Additionally, scatterplots were created to observe correlations between apoB and low-density lipoprotein cholesterol or non-high-density lipoprotein cholesterol. RESULTS: Overall mean (SD) apoB concentration was 99.8 (0.4) mg/dL, with male participants displaying significantly higher mean levels than female participants (102.4 vs 97.4 mg/dL, respectively). Mean (SD) participant age was 41.1 (0.8) years, and 8376 participants (51.9%) were female. ApoB levels were higher among older age groups. There was significant heterogeneity in mean apoB concentrations across self-identified Hispanic or Latino background groups, ranging from 95.1 mg/dL in Dominican individuals to 104.8 mg/dL in Cuban individuals. The prevalence of elevated apoB (&#x2265;130 mg/dL) was greater across higher predicted ASCVD risk categories. Among participants with a 10-year predicted ASCVD risk of 7.5% or higher, 26.5% had an elevated apoB. Median West African ancestry was lower across higher tertiles of apoB. CONCLUSIONS AND RELEVANCE: In this cohort study among participants from the HCHS/SOL, elevated apoB was present in one-quarter of a diverse cohort study of Hispanic or Latino individuals who were at intermediate or high predicted ASCVD risk. Differences in apoB distribution among Hispanic or Latino individuals may have important implications for apoB's use in ASCVD risk assessment.

Adolescent↗
PubMed2026

Epigenetic aging of colorectal mucosa in cancer development.

BACKGROUND: The past decade has seen the development of epigenetic models of aging that accurately estimate chronological age and predict disease incidence and mortality. These estimates are modulated by lifestyle and environmental factors linked to carcinogenesis, but to date this has primarily been studied in blood. METHODS: We examined epigenetic aging in normal colonic tissue (n&#x2009;=&#x2009;96), adjacent mucosa (n&#x2009;=&#x2009;245) and tumors (n&#x2009;=&#x2009;208), using models trained on age (Horvath, Hannum, Zhang), mortality (PhenoAge, GrimAge), aging rate (DunedinPACE), cellular mitotic history (EpiTOC, epiTOC2, miAGe), and telomere length (DNAmTL). RESULTS: The Horvath model was the most accurate estimator of chronological age in normal colonic mucosa, with high correlation (r&#x2009;>&#x2009;0.70) between the Horvath, Hannum, Zhang, PhenoAge and GrimAge models, and between mitotic clocks (r&#x2009;>&#x2009;0.94). All models showed similar performance in normal tissue and adjacent mucosa, but substantially more variation in estimates in tumors. Significant differences in age acceleration were present between normal and adjacent mucosa by six models (Hannum, Zhang, PhenoAge, EpiTOC, epiTOC2 and miAge), while tumors showed highly significant differences by all models. Age acceleration differed by region of the colon, with varying patterns by model type. Physical activity (PhenoAge), smoking history (GrimAge), and alcohol consumption (Horvath, mitotic clocks) were associated with epigenetic aging in adjacent mucosa, while smoking history, smoking intensity, and alcohol consumption were associated with DNAmTL in tumors. CONCLUSIONS: Our study reveals an impact of tissue type, region, and lifestyle factors on epigenetic aging, but also highlights significant heterogeneity between models and the need for careful consideration within study design.

DNA methylation↗
PubMed2026

Genome-Wide Association Analyses Identify Distinct Genetic Architectures for Extreme Early-Onset and Late-Onset T2D.

AIMS: Type 2 diabetes (T2D) is a heterogeneous disorder with substantial variation in age at onset (AAO). This study aimed to characterize the distinct genetic architectures and biological mechanisms underlying extreme AAO-defined T2D subtypes. MATERIALS AND METHODS: Using 74&#x2009;795 European-ancestry participants from the UK Biobank, we performed genome-wide association studies (GWAS) of relatively early-onset T2D (eoT2D; AAO <&#x2009;55&#x2009;years) and late-onset T2D (loT2D; AAO &#x2265;&#x2009;70&#x2009;years). We investigated subtype-specific genetic loci, SNP-based heritability, genetic correlations, Mendelian randomization (MR)-based relationships, polygenic risk scores (PRS) and phenome-wide association studies (PheWAS). Single-cell transcriptomic data from human pancreatic tissues were further used to evaluate cell-type-specific expression patterns of candidate genes. RESULTS: SNP-based heritability was substantially higher for eoT2D than loT2D (11.2% vs. 6.4%), with eoT2D displaying distinct genetic loci related to &#x3b2;-cell function and insulin regulation, including SLC30A8 and IRS1. By contrast, loT2D showed a comparatively lipid-related genetic profile, featuring APOE-associated signals and expression patterns in immune-related cell populations. Linkage disequilibrium score regression (LDSC) and MR analyses further underscored this divergence: eoT2D exhibited broader genetic overlap with cardiometabolic traits, whereas loT2D showed stronger relationships with traditional metabolic risk factors. Finally, subtype-specific PRSs improved risk discrimination beyond conventional covariates, although their clinical utility warrants further evaluation. CONCLUSIONS: Extreme AAO-defined T2D subtypes exhibit partially distinct genetic architectures, highlighting AAO as an important dimension of T2D heterogeneity and providing a framework for future age-stratified genetic risk assessment.

Type 2 diabetes↗
PubMed2026

The tunica vaginalis flap as a rescue procedure in testicular torsion: Quantifying salvage rates with matched cohorts.

INTRODUCTION: Testicular torsion is the most common urological emergency in children, and the role of tunica albuginea fasciotomy with tunica vaginalis flap (TVF) in its treatment is controversial. The objective of this study was to evaluate the outcomes among patients undergoing TVF, standard orchiopexy (SO), and orchiectomy, with attention to symptom duration. METHODS: We performed a retrospective review of boys aged 1 month-18 years who underwent surgery for testicular torsion at a single centre from 2010 to 2024. Clinical, ultrasonographic, and operative variables were abstracted, and testicular salvage was defined as a follow-up volume &#x2265;50% of the contralateral testis with blood flow. Propensity score matching for age, symptom duration, and parenchymal heterogeneity generated TVF-SO and TVF-orchiectomy cohorts. Salvage was further stratified by duration of symptoms (<6, 6-12, 12-24, >24 h). RESULTS: Among 157 patients, 31 (20%) underwent orchiectomy, 39 (25%) TVF, and 87 (55%) SO. Overall salvage was 54%, differing by procedure (SO 82%, TVF 36%, orchiectomy 0%; p < 0.001). In the TVF-SO matched cohort (n = 64), salvage was 38% for TVF and 59% for SO (p = 0.133). In the TVF-orchiectomy matched cohort (n = 38), salvage was 32% in the TVF group and 0% in the orchiectomy group (p = 0.02). Salvage after TVF declined steeply with ischemia time, with higher rates observed within 6 h of presentation. DISCUSSION: These findings suggest that TVF is used predominantly in high-risk torsion with adverse ultrasound features. When viewed descriptively, the TVF cohort showed lower follow-up viability than the SO cohort, but this difference must be interpreted in the context of the different intraoperative and preoperative risk profiles underlying procedure selection. We highlight TVF as a valuable additional consideration compared to outright orchiectomy. CONCLUSION: In this retrospective cohort, TVF was used in clinically severe torsion and was associated with follow-up viability in a subset of cases. These descriptive findings support further prospective study but should not be interpreted as evidence of equivalence or comparative benefit of TVF.

Humans↗
PubMed2026

Generation of induced pluripotent stem cell line NTUHi003-A from a patient with premature ovarian insufficiency.

Premature ovarian insufficiency (POI) is characterized by impaired ovarian function before 40&#xa0;years of age and is associated with heterogeneous etiologies. Herein, we established a human induced pluripotent stem cell (hiPSC) line, NTUHi003-A, from the peripheral blood mononuclear cells (PBMCs) of a patient with POI. The generated hiPSC line exhibited a normal 46, XX karyotype and demonstrated confirmed pluripotency. This cell line provides a valuable cellular platform for disease modeling and mechanistic studies of POI.

Humans↗
PubMed1977

Pattern detection by mongol and non-mongol subnormals.

Ten mongols and ten clinically heterogeneous subnormals matched on chronological age, mental age and digit span took part in an experiment in which tape-recorded supra-span digit sequences with different patterns were presented. There were six patterns: random, mirror (e.g. 583385); same-digit pairs (e.g. 558833), same-digit throughout (e.g. 333333), couplet repetition (e.g. 585858) and triplet repetition (583583). The numbers of digits correctly recalled in any order by the mongols in the various conditions ranked from least to most were: random, mirror, same-digit pairs, same-digit messages, triplet repetition and couplet repetition. The rank order for the non-mongols was the same except that the positions of couplet and triplet repetition were reversed. Mongols had significantly poorer recall for random, mirror and same-digit pair messages than non-mongols but were their equals in other conditions. The mongols' performance was more sensitive to pattern than the performance of the other subjects. There was some evidence that, in the messages with same-digit pairs and the same digit throughout, all subjects (but mongols in particular) tended to insert new digits into the response sequence and that the digit introduced was the next one in simple arithmetic progression. It would appear that the hypothesis about poor auditory-vocal channelling capacities of mongols needs qualification.

Adult↗
PubMed1977

A study of the efficacy of the Feingold diet on hyperkinetic children. Some favorable personal observations.

A study was conducted with 59 children, ages 6 to 14 years, heterogeneously grouped together under the diagnosis of the hyperkinetic, minimal brain dysfunction syndrome. Of 32 who were able to tolerate the Feingold salicylate-low and additive-free diet, 11 were markedly improved. A placebo effect could not definitely be ruled out, but the startling changes seen in patients who had been followed for years with other forms of therapy suggest strongly that this improvement was genuine.

Adolescent↗