[Plasma TSH responses after thyrotropin-releasing hormone loading in young healthy subjects, aged healthy subjects and patients with senile dementia of Alzheimer type].
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
While there is accumulating evidence to indicate the presence of functional abnormalities in T cells from aged healthy humans, their cellular basis remains unclear. By using two-color immunofluorescence and multiparameter flow cytometry we show that (a) the number of peripheral blood antigen receptor-positive (TcR-CD3+) T cells is significantly lower in aged than in young adults; (b) the numbers of E-rosette-forming (CD2+) cells are maintained in the elderly due to a reciprocal increase in the frequency of TcR-CD3- cells, which constitute only a minor lymphocyte subpopulation in young adults, and (c) TcR-CD3-CD2+5- lymphocytes exhibit the phenotypic features of natural killer (NK) cells. By using functional assays we show the TcR-CD3-CD2+16+ lymphocytes are indeed NK cells because they are activated by and lyse NK targets. In contrast, they are unresponsive to either phytohemagglutinin or mitogenic CD2 monoclonal antibody stimulation, which in turn activates TcR-CD3+CD2+16- T cells. We conclude that the increase in TcR-CD3-CD2+ NK cells masks the T cell reduction in aged humans by normalizing CD2+ cell frequencies. However, NK cells cannot functionally substitute the thymus-derived lymphocytes they replace.
"Healthy aging" is the theme of the International Nurses Day 1992, announced by the International Council of Nurses. This article discusses briefly critical questions, among which the following: How is the world aging? What are the most important health issues? What does "Healthy aging" really mean? What is the Greek philosophical view for aging? And what are the problems and perspectives of the nursing care of the elderly?
We studied six healthy young males (young group; mean age 30.0 +/- SD 1.8 years, FVC 4.5 +/- 80.45 l and FEV1.0/FVC 87.6 +/- 4.3%), and five aged healthy males (aged group; age 63.8 +/- 3.0 years, FVC 3.40 +/- 0.22 l and FEV1.0/FVC 75.9 +/- 3.2%) to evaluate the variability of pulmonary function. We measured flow-volume curves, closing volumes, functional residual capacities (FRC) and airway resistances (Raw) five times in different days in each person. The coefficients of variation in FVC and FEV1.0 in both groups were less than 5%, and there were no significant differences in these coefficients between the two groups. Although the coefficients in FEV1.0/FVC in both group were less than 5%, there was a significant difference between the two groups. The coefficients in flow at 50% FVC (V50), maximal midexpiratory flow (MMF) and peak expiratory flow rate (PEFR) in the aged group were significantly larger than those in the young group. The coefficients in closing volume, FRC, Raw and specific airway conductance (SGaw) using body plethysmography exceeded 10% in both groups, and the coefficients in Raw and SGaw in the aged group were significantly larger than those in the young group. These results suggest that aging worsens the variabilities of respiratory function in FEV1.0/FVC, MMF, V50, Raw and SGaw.
Brain metabolism has been measured with positron emission tomography and 18[F] fluoro-2-deoxyglucose. Brain metabolic function remains age invariant in healthy aged subjects 21 to 83 years. Brain metabolism remains unchanged in the mild-moderate severity Alzheimer's disease group and significantly reduced throughout the brain in the late-severe form. Serial assessments over 2 1/2 years of brain metabolic function in an Alzheimer's disease subject with positron emission tomography and 18[F]-fluoro-2-deoxyglucose revealed initial reductions in the parietal lobe and regions prior to neuropsychological changes. Marked elevations in brain metabolism were found in young adult Down syndrome subjects while age-related declines were found in the middle aged (non-demented) Down syndrome subjects and further reductions in the demented Down syndrome individuals.
BACKGROUND: Birthweight readily measurable marker of fetal growth that may influence health across the lifespan. We aimed to investigate the potential causal association between birthweight and healthy aging and to identify the mediating roles of subsequent socioeconomic, behavioral, functional, and disease-related factors to inform life-course strategies to promote healthy aging and reduce health inequities. METHODS: We performed two-sample Mendelian randomization analyses in European-ancestry participants to estimate the effect of birthweight (n = 298,142-423,683) on two robust, composite healthy aging phenotypes (genetically independent phenotype of aging (aging-GIP) and multivariate aging-related genetic factor (mvAge)) and six individual aging phenotypes, including healthspan, resilience, parental lifespan, self-rated health, phenotypic age deceleration, and 90th percentile self-longevity (n = 34,710-1,958,774), and screened for 100 candidate mediators (n = 14,267-1,812,017) using a two-step mediation analysis. RESULTS: Genetically determined each 1-SD higher birthweight was associated with higher aging-GIP (β [95% CI] in different models ranging from 0.131 [0.066-0.196] to 0.162 [0.089-0.235] SDs) and mvAge (0.036 [0.010-0.063] to 0.045 [0.024-0.067]), independent of later-life obesity indicators; also with more interpretable benefits, including 12%-16% higher odds of longer healthspan, a 0.079-0.089 SD improvement in resilience, and a 1.22-1.74 year increase in parental lifespan. Of 100 candidates, 26 and 25 mediated the effect of birthweight on aging-GIP and mvAge, respectively, including socioeconomic indicators (education, household income, occupational attainment; individual mediation proportion: 12.72%-27.79%); behaviors (e.g., cheese intake, age at first sex; 10.38%-29.56%); physical functions (e.g., blood pressure, grip strength; 7.57%-42.65%); and cardiometabolic diseases (e.g., type 2 diabetes, cardiovascular diseases; 25.02%-70.11%). CONCLUSIONS: Higher birthweight within the normal range directly promotes healthy aging, mediated by multifaceted modifiable factors. Our findings advocate adopting a life-course approach to foster healthy aging, starting with optimal birthweight and extending to interventions that enhance socioeconomic status, promote healthy behaviors, strengthen physical functions, and prevent cardiometabolic diseases.
Photopic temporal contrast sensitivity for healthy eyes of observers 65 years old and older is compared with retinal-illuminance-matched sensitivity of younger eyes. The older observers are significantly less sensitive for frequencies between 10 and 45 Hz. Although there is a slight shift to slower flicker rates in the mean contrast sensitivity function for older observers, this trend is not statistically significant, suggesting that there is relatively little loss of temporal resolving power of the visual system with healthy aging. These are preliminary results from an ongoing study of temporal contrast sensitivity in healthy aging eyes.
An experiment is reported that addresses semantic priming effects, lexical repetition effects, and the influence of context on meaning selection for ambiguous words in 32 healthy aged individuals and 32 individuals with Senile Dementia of the Alzheimer Type (SDAT). On each of 232 trials, subjects pronounced each of three words. The four major conditions were concordant (music-organ-piano), discordant (kidney-organ-piano), neutral (ceiling-organ-piano), and unrelated (kidney-ceiling-piano). In order to address lexical repetition effects, target words were repeated across Blocks 1 and 2 but not in Block 3. Analyses of naming latencies indicated that semantic priming effects and lexical repetition effects were slightly larger in SDAT individuals than in healthy aged individuals. More importantly, healthy aged individuals produced normal selective access of the contextually biased meaning whereas SDAT individuals produced evidence consistent with nonselective meaning access. These results are discussed within both an attentional and a connectionist account of homograph disambiguation.
Using Norland-Cameron photon-absorption technique, bone mineral content of 436 healthy aged was measured and compared with that of 198 healthy, aged 21-50. Bone mineral content of postmenopausal females decreased continuously with age and bone mineral content of males began to decrease at age over 70. Bone width and menopausal age seemed to be important factors influencing bone mineral content, but previous physical activity seemed to have no effect on the bone mineral content of the aged.
Twenty-four healthy aged individuals with above-average intellectual function were studied with use of a low-field-strength (0.02-T) magnetic resonance (MR) imager. The group was carefully selected so as not to include persons with signs of arteriosclerotic diseases, major somatic disease, or a history of brain disease or dementia in the family. The width of the subarachnoid spaces and lateral ventricles, as well as the frequency and degree of brain white-matter lesions, were described with the use of a visual rating scale. White matter lesions were found in less than 9% of the subjects. The lateral brain ventricles were enlarged in 8% of all individuals and the cortical cerebrospinal fluid (CSF) spaces in more than 40% of all individuals. Moreover, T1 and T2 were estimated in different brain areas, and a positive correlation between T1 in the frontal white matter and age was found. A computer-assisted classification procedure was used to estimate brain tissue and CSF areas. The results of this procedure strongly correlated with the visually estimated ventricular size.
Selected phonatory behaviors of healthy aged and young men and women were compared. Inverse-filtered air flow, electroglottograph (EGG), and intraoral air pressure signals were recorded as subjects phonated in each of four conditions: normal, soft, loud, loud/high pitched. Minimum flow offset, flow amplitude, air flow duty cycle, EGG duty cycle, estimated subglottal pressure, and fundamental frequency were derived from the recorded signals and compared among age/gender groups. Males had significantly greater flow amplitude than females regardless of age. Significant Age x Sex interactions were found for fundamental frequency and duty cycle measures. Duty cycles and fundamental frequency increased for males and decreased for females with aging. For the normal phonatory condition, aged men had significantly greater duty cycle measures, flow amplitude, and estimated subglottal pressure than young men. There were significant differences in fundamental frequency and EGG duty cycle between aged and young women during normal phonation. It was concluded that the effects of aging on phonatory behaviors are different in degree and kind for men and women. Fewer significant age-related differences in phonatory measures for women than men were consistent with reports of less age-related laryngeal degeneration in females than males.
To evaluate the impact of healthy aging on specific features of endogeneous LH secretion and clearance, we applied deconvolution analysis to 24-h serum immunoradiometric LH concentration series obtained in normal men whose ages ranged from 21-73 yr. Deconvolution analysis was employed to quantitate the number, amplitude, duration, and mass of individual LH secretory bursts underlying the serum LH concentration profiles, and simultaneously estimate the half-life of LH in individual men. Plasma total and free testosterone and estradiol concentrations and body mass index (a measure of relative adiposity) were studied as possible significant covariates of age and LH secretion. We found that age was a negative determinant of LH secretory burst amplitude (r = -0.519, P = 0.013), and a positive predictor of LH secretory burst frequency (r = +0.435, P = 0.043) and basal LH secretory rates (r = +0.486, P = 0.029). Increasing age also correlated positively with LH secretory burst half-duration (duration of the secretory event at half-maximal amplitude, r = +0.656, P less than 0.001). In contrast, age did not relate to daily pulsatile LH production rate, the mass of LH secreted per burst, or the mean (24-h) serum concentration of immunoradiometric LH. Age correlated negatively with serum free testosterone (r = -0.622, P = 0.0034) but not estradiol concentrations. The serum free testosterone concentration also declined significantly with increasing body mass index (r = -0.519, P = 0.023). Although there were strong combined effects of age, body mass index, and LH secretory burst amplitude on serum free testosterone concentrations (P = 0.0006, multi-r value 0.820), LH secretory burst amplitude was the most prominent single determinant of blood androgen concentrations.
We assessed the overnight sleep and breathing as well as daytime medical, sleep, and psychological status of a group of 34 healthy older persons. Analyses indicated that sleep-disordered breathing (SDB) was not related to any aspects of daytime functioning as measured in this study and that persons with an apnea + hypopnea index (AHI) greater than or equal to 5 (M AHI = 14.6) were not significantly impaired relative to those with lower levels of SDB (M AHI = 1.0) on any aspect of daytime performance. We conclude that SDB occurring in healthy aged persons is probably not of immediate concern and that the use of a cutting score of AHI greater than or equal to 5 for diagnosis of sleep apnea syndrome is not indicative in healthy aged persons. However, these results may not be applicable to older persons who are not in the excellent state of health that was required for participants in our study.
The relationship between quantitative measurements of brain white-matter hyperintensity (WMH), assessed by magnetic resonance imaging and neuropsychological functions, was explored in demented patients and healthy aged individuals with and without WMH in 12 brain regions. The prevalence of WMH was significantly higher in vascular dementia compared with Alzheimer's disease, especially in posterior periventricular regions. Results showed no difference in any neuropsychological measurement between healthy aged adults with and without WMH. The demented patients with WMH were more impaired in tests of visuoconstruction, attention, finger-motor speed, and latency of tactile identification of objects compared with patients without WMH. These impairments were related mainly to posterior periventricular WMH. There was no relationship between WMH and global cognitive functioning in the demented patients. The degree of WMH was related to age and blood pressure. The data suggest that specific regional WMH may result in specific neuropsychological impairments.
To examine the biological quality and physiologically pulsatile mode of endogenous luteinizing hormone release in active, healthy aging men, we used the rat interstitial-cell testosterone in vitro bioassay to probe LH bioactivity in response to (a) endogenous gonadotropin-releasing hormone (GnRH) action (basal pulsatile bioactive LH secretion); (b) exogenous GnRH stimulation (10 micrograms IV pulses); and (c) inhibition of endogenous estrogen negative feedback (treatment with a nonsteroidal antiestrogen, tamoxifen). Basally, some healthy older men exhibited evidence of neuroendocrine dysfunction, reflected by irregular bursts of bioactive LH release followed by transiently low plasma bio:immuno (B:I) LH ratios. However, mean basal plasma bioactive LH concentrations, B:I ratios, and spontaneous LH pulse properties (peak frequency, amplitude, duration, and enhanced B:I ratios within LH peaks) were not altered in older men. On the other hand, augmentation of bioactive LH secretion and enhancement of plasma B:I ratios by pulsed injections of exogenous GnRH were either significantly reduced or absent in older men. In addition, although tamoxifen increased bioactive LH pulse frequency in both age groups and facilitated exogenous GnRH action in some subjects, older men increased their 12-h mean bioactive LH concentrations, B:I ratios, and bioactive LH peak amplitudes to a significantly lesser degree than young men. In summary, young and older healthy men exhibit similar mean basal plasma bioactive LH concentrations and spontaneous LH pulse properties. However, pituitary bioactive LH reserve is markedly attenuated in older men challenged with either exogenous GnRH or antiestrogen. Accordingly, we conclude that healthy aging men manifest an impaired secretory reserve for biologically active LH release.
Nucleosomes are the minimal repeating units of chromatin. Their dynamic assembly and disassembly underpins chromatin organization and genome regulation. However, it remains unclear how intrinsic nucleosome stability contributes to higher-level yet fundamental cellular and organismal properties-such as preservation of cell identity, lineage specification, stress resilience and ultimately healthy aging. To address this, we tested the impact of decreased intrinsic nucleosome stability across multiple cell, tissue and organismal models by introducing histone mutants that weaken histone-histone interactions. While nucleosome instability did not broadly alter global chromatin accessibility, DNA damage, cell proliferation or viability, it impaired lineage-specific gene expression programs, altered lineage specification and activated intrinsic inflammatory and stress pathways in a manner reminiscent of aging in mouse tissues and human cells. Consistently, nucleosome instability accelerated the onset of age-associated transcriptional alterations and functional decline in Caenorhabditis elegans and Drosophila melanogaster, and reduced cellular resilience to exogenous perturbations-including environmental, epigenetic and mitotic stress-in human cells and Saccharomyces cerevisiae. These cross-species findings identify nucleosome stability as an evolutionarily conserved epigenetic safeguard that preserves cell identity and stress resilience and supports organismal function and healthy aging.
Modest differences in the clearance of the 5HT3 antagonist, ondansetron, among different age groups were detected in two groups of healthy elderly volunteers, one group aged 61 to 74 years ("elderly") and the other 75 to 82 ("aged") years, in addition to young healthy subjects. Both a single 0.15 mg/kg intravenous dose and a single 8 mg oral dose were administered according to a randomized crossover design with a minimum 3-day washout period between treatments. Mean plasma clearance decreased (young, 0.349 L/hr/kg; elderly, 0.279 L/hr/kg; aged, 0.214 L/hr/kg; p less than 0.05) with increasing age. Volume of distribution at steady state was unaffected by age (young, 1.81 L/kg; elderly, 1.94 L/kg; aged, 1.71 L/kg), resulting in increases in mean plasma half-life (young, 3.4 hours; elderly, 4.5 hours; aged, 5.4 hours) and mean absolute bioavailability (young, 57%; elderly, 61%; aged, 69%) with increasing age. Female subjects cleared ondansetron more slowly than males (p less than 0.05), resulting in higher absolute bioavailability. Ondansetron was well tolerated by all age groups with no increase in the number of adverse events observed in older volunteers.
Few studies have assessed the role of pituitary and gonadal hormones on age-related changes in sexual behavior in healthy men. We conducted a retrospective and prospective evaluation of sexual function and behavior in 77 healthy married men aged 45 to 74 years. The subjects were studied in the sleep laboratory for four nights with the last night devoted to sequential blood sampling every 20 minutes. Significant age-related decreases in sexual desire, sexual arousal and activity, and increases in erectile problems were noted. Aging was negatively correlated with bioavailable testosterone (bT), was positively correlated with luteinizing hormone (LH), and was not related to total testosterone, estradiol, and prolactin. Bioavailable testosterone, and the ratio of bT over LH showed a close association with several sexual behavior dimensions while total testosterone, estradiol, and prolactin demonstrated few or no behavioral relationships. The age-related effect of bT was, however, a more important determinant of the reported behavioral differences than were the effect of bT independent of age. There was no evidence that changes in circulating hormones contribute to erectile disorders in healthy aging men.