Biological Age (biological + age)

Distribution by Scientific Domains
Medical Sciences42%

Selected Abstracts

Hormonal and Biochemical Parameters and Osteoporotic Fractures in Elderly Men

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2000
Dr. Jacqueline R. Center
Abstract Low testosterone has been associated with hip fracture in men in some studies. However, data on other hormonal parameters and fracture outcome in men is minimal. This study examined the association between free testosterone (free T) estradiol (E2), sex hormone-binding globulin (SHBG), 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), insulin-like growth factor I (IGF-I), and fracture in 437 elderly community-dwelling men. Age, height, weight, quadriceps strength, femoral neck bone mineral density (FN BMD), and fracture data (1989,1997) also were obtained. Fractures were classified as major (hip, pelvis, proximal tibia, multiple rib, vertebral, and proximal humerus) or minor (remaining distal upper and lower limb fractures). Fifty-four subjects had a fracture (24 major and 30 minor). There was no association between minor fractures and any hormonal parameter. Risk of major fracture was increased 2-fold for each SD increase in age, decrease in weight and height, and increase in SHBG, and risk of major fracture was increased 3-fold for each SD decrease in quadriceps strength, FN BMD, and 25(OH)D (univariate logistic regression). Independent predictors of major fracture were FN BMD, 2.7 (1.5,4.7; odds ratio [OR]) and 95% confidence interval [CI]); 25(OH)D, 2.8 (1.5,5.3); and SHBG, 1.7 (1.2,2.4). An abnormal value for three factors resulted in a 30-fold increase in risk but only affected 2% of the population. It is not immediately apparent how 25(OH)D and SHBG, largely independently of BMD, may contribute to fracture risk. They may be markers for biological age or health status not measured by methods that are more traditional and as such may be useful in identifying those at high risk of fracture. [source]

A new source of aging?

JOURNAL OF COSMETIC DERMATOLOGY, Issue 2 2009
Helen Knaggs MD
Summary There has been a considerable increase in understanding how skin ages, along with significant progress toward the correction and prevention of the visible signs of aging. However, there are still many unknown factors regarding why we age , and why we all seem to age differently. An area of high interest is the biological or intrinsic processes that affect our appearance over time. This article describes a recent discovery of a membrane bound enzyme proven to be present in skin and increases its activity as biological age increases. The enzyme is located on the external surface of both fibroblast and keratinocytes, and generates free radicals. Therefore, as we age there appears to be a biological mechanism that further increases the production of free radicals. Additionally, there appears to be a relationship between activity of the enzyme and appearance. Data showed that subjects who look younger than their biological age had lower enzyme activity and conversely, subjects who looked older than their biological age had higher enzyme activity. Free radicals are believed to be a major contributing factor in the production of fine lines and wrinkles by destroying the collagen and elastin network keeping skin supple and firm. [source]

Gene expression profiles associated with aging and mortality in humans

AGING CELL, Issue 3 2009
Richard A. Kerber
Summary We investigated the hypothesis that gene expression profiles in cultured cell lines from adults, aged 57,97 years, contain information about the biological age and potential longevity of the donors. We studied 104 unrelated grandparents from 31 Utah CEU (Centre d'Etude du Polymorphisme Humain , Utah) families, for whom lymphoblastoid cell lines were established in the 1980s. Combining publicly available gene expression data from these cell lines, and survival data from the Utah Population Database, we tested the relationship between expression of 2151 always-expressed genes, age, and survival of the donors. Approximately 16% of 2151 expression levels were associated with donor age: 10% decreased in expression with age, and 6% increased with age. Cell division cycle 42 (CDC42) and CORO1A exhibited strong associations both with age at draw and survival after draw (multiple comparisons-adjusted Monte Carlo P -value < 0.05). In general, gene expressions that increased with age were associated with increased mortality. Gene expressions that decreased with age were generally associated with reduced mortality. A multivariate estimate of biological age modeled from expression data was dominated by CDC42 expression, and was a significant predictor of survival after blood draw. A multivariate model of survival as a function of gene expression was dominated by CORO1A expression. This model accounted for approximately 23% of the variation in survival among the CEU grandparents. Some expression levels were negligibly associated with age in this cross-sectional dataset, but strongly associated with inter-individual differences in survival. These observations may lead to new insights regarding the genetic contribution to exceptional longevity. [source]

Cellular senescence in pretransplant renal biopsies predicts postoperative organ function

AGING CELL, Issue 1 2009
Liane M. McGlynn
Summary Older and marginal donors have been used to meet the shortfall in available organs for renal transplantation. Post-transplant renal function and outcome from these donors are often poorer than chronologically younger donors. Some organs, however, function adequately for many years. We have hypothesized that such organs are biologically younger than poorer performing counterparts. We have tested this hypothesis in a cohort of pre-implantation human renal allograft biopsies (n = 75) that have been assayed by real-time polymerase chain reaction for the expression of known markers of cellular damage and biological aging, including CDKN2A, CDKN1A, SIRT2 and POT1. These have been investigated for any associations with traditional factors affecting transplant outcome (donor age, cold ischaemic time) and organ function post-transplant (serum creatinine levels). Linear regression analyses indicated a strong association for serum creatinine with pre-transplant CDKN2A levels (p = 0.001) and donor age (p = 0.004) at 6 months post-transplant. Both these markers correlated significantly with urinary protein to creatinine ratios (p = 0.002 and p = 0.005 respectively), an informative marker for subsequent graft dysfunction. POT1 expression also showed a significant association with this parameter (p = 0.05). Multiple linear regression analyses for CDKN2A and donor age accounted for 24.6% (p = 0.001) of observed variability in serum creatinine levels at 6 months and 23.7% (p = 0.001) at 1 year post-transplant. Thus, these data indicate that allograft biological age is an important novel prognostic determinant for renal transplant outcome. [source]

Deep brain stimulation for trauma: Patient selection and evaluation

MOVEMENT DISORDERS, Issue S3 2002
Günther Deuschl MD
Abstract The selection of patients with movement disorders for deep brain stimulation is becoming a common neurological and neurosurgical task. Deep brain stimulation is suitable for different forms of tremor, which can often not be treated with medication. This suitability applies for essential tremor, monosymptomatic tremor at rest, cerebellar or multiple sclerosis tremor, Holmes' tremor, primary writing tremor or tremor in neuropathies. The appropriate selection of patients is critical for the outcome of surgical relief of tremors. Considering the risks of any stereotactic intervention, the following must apply: (1) motor symptoms lead to a relevant disability in activities of daily living, despite optimal medical treatment; (2) biological age of the patient; (3) neurosurgical contraindications; (4) the patient is neither demented nor severely depressed. If these conditions are fulfilled, the individual chances of improvement of the target symptoms need to be checked, based on the following guidelines: (1) the kind of tremor, (2) the natural course of the tremor, (3) the chances for medical treatment in a particular patient, (4) the outcome of surgery in a specific condition, (5) the individual risks for a patient to suffer from complications. The outcome of surgery for tremor depends on the clinical type and distribution. Distal limb tremors are easier to treat than proximal limb tremors. Intention tremor is more difficult to treat than rest or postural tremor. The indication for surgical treatment depends on the analysis of the individual risk,benefit ratio, which also has to take into account the patients' social, professional, and familial background. The patient needs to be well informed about his individual risk,benefit ratio and of alternative treatments, before undergoing stereotactic surgery. © 2002 Movement Disorder Society [source]

Evaluation of the scientific impact, productivity and biological age based upon the h-index in three Latin American countries: the materials science case

ANNALEN DER PHYSIK, Issue 4 2009
A.H. Romero
Abstract We discuss the scientific impact of Latin American scientists in the field of materials science. The analysis is based on the h-index as the scientometric index used to quantify the scientific productivity of an individual. In particular, we focus our analysis in México, Chile and Colombia. We compare the level of productivity between all these countries. We also analyzed the h-index as function of the biological age, by using the first year of publication of a given scientists as a reference and discussed the general distribution of its quantification. We do not find a clear relationship between these two quantities. Based in our results we propose some political measures that these countries could implement to improve productivity as well as scientific development in this field. [source]