Aging of arterial extracellular matrix elastin: etiology and consequences

In 50 patients with benign ovarian tumours, 39 malignant ovarian carcinoma patients and 39 age-matched healthy women, plasma levels of thrombin-antithrombin III complex and D-dimer were determined as well as CA 125. The coagulation activation marker thrombin-antithrombin III complex and D-dimer levels were elevated in the malignant group compared to the benign and control groups. The results suggest that coagulation and fibrinolysis must play a prominent role in ovarian cancer. Moreover, D-dimer and thrombin-antithrombin III were equally useful as CA 125 for the discrimination of patients with benign or malignant ovarian tumours as evidenced by receiver operating and likelihood ratio calculations.     

Aging effect on inductive capacity of human demineralized bone matrix

Demineralized bone powder (DBP) prepared from human cortical bone was implanted into subcutaneous pouches of athymic Nu/Nu mice for 28 days. The osteoinductive capacity was evaluated by histomorphometry of the induced cartilage and bone, and by alkaline phosphatase activity in the implant. Very small amounts of new bone and cartilage were found at histological analysis, confirming that human DBP is much less osteoinductive than that from other species. Whereas the morphometric data of the implants from the young and aged donors were not significantly different, the alkaline phosphatase activity was significantly lower in the implants from the old donors than from the younger ones. This difference between the morphometric and biochemical results could reflect the fact that the enzymatic activity is already present in the osteoprogenitor cells. At 28 days, the osteoblastic activity in contact with DBP from the aged group is characterized by a decrease in the enzymatic amount which is not yet visible at the tissue level. This tendency to a decrease in the osteoinductive capacity of bone matrix is an additional aspect of the age-related alterations which occur in bone tissue and could be attributed to modifications of different proteins of the bone matrix, including bone morphogenetic protein.     

Cultured epithelial autografts: diving from surgery into matrix biology

Cultured epithelial autografts offer an exciting approach to cover extensive skin wounds. The main problem of this method is mechanical instability during the first weeks after grafting. There is evidence that the shortcomings of autografting cultured keratinocytes result from the lack of a mature and functional dermo-epidermal junction. This article summarizes the current knowledge regarding the de novo formation of the dermo-epidermal junction and the dynamics of "take" and stabilization of cultured epithelial autografts. Future strategies are discussed of how to improve and accelerate the process conferring definitive stabilization of cultured epithelial autografts including the potential therapeutic use of transglutaminase as well as cocultivation of a dermo-epidermal equivalent in order to facilitate a permanent skin replacement.     

Aging and bereavement

This paper compares the grief responses of widows and widowers of different age groups over the 1st year of bereavement. The results strongly suggest that older widows and widowers perceive themselves as adjusting better to their loss and suffering from less depression and fewer anxiety symptoms than their younger counterparts. Furthermore, the oldest widows/widowers demonstrate the most consistent improvement in their levels of distress over time. Thus, when it comes to coping, older persons are not at the disadvantage that certain stereotypes and "clinical wisdoms" have previously suggested. Seniors are every bit as adaptive and able to cope with the severest forms of stress as anyone else, and they are, if anything, less prone to depression than are younger individuals.     

Aging and mitochondria

Aging is a complex physiological phenomenon and several different theories have been elaborated about its origin. Among such theories, the 'mitochondrial theory of aging', which has gained a large support, indicates the accumulation of somatic mutations of mitochondrial DNA leading to the decline of mitochondrial functionality as one of the driving forces for the process itself. In this review data on rat and man from our laboratory and from recent literature have been thoroughly examined and compared in order to provide the 'state-of-the-art' on the role of mitochondria in aging. Alterations of structure and expression of mitochondrial genome with aging, to find out the eventual relevant changes of mitochondrial biogenesis, have been studied in rat whereas the relationship between cytochrome c oxidase activity and 'common deletion' has been studied in man. Results on the effect of acetyl-L-carnitine on the mitochondrial functionality are also reported.     

Aging and pharmacology

Research on aging and pharmacology in humans has been termed geriatric clinical pharmacology, which is an established subdiscipline within the broad field of clinical pharmacology. This article reviews information relevant to clinical cancer research and the care of older patients with cancer. Accordingly, the current state of knowledge on drug utilization, pharmacokinetics, pharmacodynamics, adverse drug events, drug interactions, polypharmacy, adherence to treatment, and clinical research considerations are reviewed. Although a review of the literature on aging and cancer chemotherapy is not included in this particular presentation, information is very sparse. Thus, there is significant potential for valuable contributions from clinical research through partnerships between geriatric clinical pharmacologists and medical oncologists.     

Aging

Aging, a wearing-out process which affects everything inanimate and animate, is accelerated by abuse of decelerated by care. The psychologic reaction of aging persons vary considerably. The concept of growing older is much more satisfactory and pleasant than the concept of being old, since the former is applicable to everyone regardless of age whereas the latter carries a finite significance as deterioration progresses. Chronologic age is much less important than biologic age. The desideratum is not longevity but rather a long, useful and meaningful life. Although heredity is of importance in longevity, it is a factor over which at present we have no control. However, we can influence the aging process according to whether we care for or abuse the body. The principal factors in accelerated aging, in order of importance, are: 1) tobacco use (particularly cigarette smoking), 2) lack of exercise, and 3) obesity. Conversely, abstinence from tobacco, exercise within tolerance, and avoidance of obesity not only decelerate aging but result in a better quality of life.     

Hydromechanics and biology

To exemplify relations between biology and hydrodynamics the Reynolds number range and the effects of viscosity and inertia in swimming and flying organisms is discussed. Comparing water beetles and penguins it is shown, that the technical drag coefficient is an adequate means to describe flow adaptation in animals. Compared to technical systems, especially the penguins'drag coefficient is astonishingly low. Furthermore, the question, why comparatively thick bodies in penguins and dolphins show rather low drag is discussed. Distributed boundary layer damping in dolphins and secretion of special high molecular slimes in fishes help to keep flow characteristics laminar. As an example of one easily understood thrust mechanism, the drag inducing pair of rowing legs in water, beetles is morphologically and hydrodynamically analysed. Fish swimming is discussed as a locomotion principle using lift components. Thrust generation by the moving tail fin of a fish is analysed in detail. Coming back to the influence if Reynolds number, it is finally shown, how very small, bristle bearing swimming legs and wings of insects make use of viscosity effects for locomotion.     

Aging and heparin-related bleeding

BACKGROUND: Many studies have suggested that elderly patients are at increased risk of bleeding during heparin therapy. OBJECTIVE: To establish whether the risk of bleeding in the elderly results from concomitant risk factors or is associated with the aging process itself. METHODS: One hundred ninety-nine patients who presented with proximal deep vein thrombosis were treated with a standard intravenous heparin protocol in a double-blind, randomized, prospective study. Bleeding complications were monitored. Activated partial thromboplastin times and heparin levels were assessed 4 to 6 hours after a standard intravenous heparin bolus and infusion. Heparin doses and heparin levels were also assessed after stable therapeutic heparin infusion rates were established. RESULTS: There was an increase in total and major bleeding complications with aging (P < .05) that was not accounted for by standard risk factors for bleeding. Aging was associated with an increase in heparin levels (r = .239, P = .003) and a tendency for an increase in activated partial thromboplastin time (r = .134, P = .07) after standard heparin doses. Aging was also associated with lower heparin dose requirements (r = .267, P = .003) after therapeutic activated partial thromboplastin times were achieved. CONCLUSION: Aging is a risk for heparin-related bleeding that may be explicable by age-related changes in the pharmacologic characteristics of heparin.     

电磁纯铁磁时效现象与人工时效工艺的改进

阐述了电磁纯铁的磁时效现象及其机理,并结合太钢无磁时效优质电磁纯铁的质量控制水平和磁时效检验方法,提出了人工时效处理的改进工艺。通过对比试验,论证了改进工艺的可行性。     

Aging and ethanol metabolism

The effect of aging on the distribution and elimination of ethanol was studied in a group of 50 healthy subjects ranging in age from 21 to 81 yr (mean, 53.3). Ethanol was administered in a continuous 1-hr infusion at a mean rate of 375 mg/m2 body surface area/min (equivalent to a mean dose of 0.57 gm/kg body weight). Serial blood samples for the determination of ethanol concentration was obtained at 15- to 30-min intervals for up to 4 hr post infusion. Ethanol elimination and distribution were evaluated with the aid of a two-compartment model. Rates of ethanol elimination were not affected by age. Peak ethanol concentration in blood water at the end of the infusion period was correlated with age (r= 0.55, p less than 0.001). Lean body mass and total volume of distirbution fo the ethanol were negatively correlated with age. The smaller volume of distirbution, in association with the decreased lean body mass, most likely explains the higher peak ethanol concentration found in the blood after administration of an ethanol does on the basis of surface area in the old as compared with the young subjects. This study demonstrates that age-related changes in body composition are important factors in the study of ethanol metabolism and its pharmacologic effects.     

Aging and apoptosis control

The phenomenon of aging is distinct from processes associated with advanced age known to increase risk of diseases, such as cancer. Furthermore, the process of aging is not necessarily related to phenomena such as in vitro replicative senescence; however, any unifying hypothesis of aging must account for all age-dependent phenomena, including senescence. It is proposed that apoptosis forms the ultimate protective process for preservation of phenotypic fidelity in multicellular organisms since it is the process by which the organism detects damage and replaces the defective cell. Time-dependent degeneration of apoptosis control is the rate-limiting step in the process of aging.     

Aging and depression.

The assumption that aging is associated with an increased risk of depression is a recurring theme in the gerontological literature. Yet empirical studies that have investigated the relation between aging and depression do not show consistent support for this assumption or hypothesis. Indeed, some investigators contend that the thrust of empirical evidence favors a view of elderly persons as relatively immune from depression, at least in contrast to their younger adult counterparts. The present article examines the empirical basis for these disparate claims in the context of a careful review of the growing body of research on the relation between aging and depression. The central conclusion of the review is that diverse measurement approaches, coupled with flaws in design and analysis, make it difficult to draw any definitive conclusions regarding the age-depression relation at this time. The article concludes with a discussion of implications for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular biology of aging. 8. Aging of intermitotic cells--relationship to protein synthesis in the mucosa of the small intestine

1. The incorporation of 14C-leucine in a cell free system of intestine mucosa is diminished in aging. 2. The absence of 2-mercaptoethanol in the system of incorporation increases the age differences. 3. By combination of a system from intestine with liver preparation we observed a participation of both the microsomes and the postmicrosomal supernatant. 4. The activity of Ribonuclease is not changes in the aging process. Our results demonstrated the alterations of the intermitotic cells in aging.     

Aging and the adrenal cortex

Aging in humans is accompanied by an increase in adrenal glucocorticoid secretion and a decline in adrenal androgen synthesis and secretion. The intense interest in adrenal function in aging individuals in recent years is in large measure related to the potential impact of cortisol excess in the development of cognitive impairment and hippocampal neuronal loss, and to the desire to provide hormone replacement and healthy aging. Although the preliminary data is tantalizing, solid scientific evidence are not at hand. It is apparent that both issues are extremely complex. Dehydroepiandrosterone (DHEA) and its 3 beta-sulfate are fascinating molecules, including their synthesis and actions in the brain. Recent studies have shown that DHEA-sulfate (DHEA-S), but not DHEA, activates peroxisome proliferator-activated receptor alpha (PPAR alpha) in the liver, an intracellular receptor belonging to the steroid receptor superfamily. Thus, DHEA-S may serve as a physiological modulator of liver fatty acid metabolism and peroxisomal enzyme expression, and thereby may contribute to the anticarcinogenic and chemoprotective properties of this intriguing class of endogenous steroids. The life-sustaining role of adrenal cortisol secretion and its regulation of metabolism via catabolic actions may be modulated by its partner DHEA and DHEA-S. During the anabolic growth period (childhood and early adulthood) the body is exposed to relatively high levels of DHEA/DHEA-S but to relatively or absolutely high levels of cortisol during infancy and the aging phase. The cortisol/DHEA-S ratio during the life span follows a U-shape curve, which may be telling us to explore these two critical adrenal steroids in tandem.     

Aging embrittlement and grain boundary

“Clean” 3.5NiCrMoV steels with limited contents in trace elements (P, Sn, As, Sb) are commonly provided for manufacturing big rotor shafts. The possible increase in temperature in future steam turbines has promoted the development of “superclean” steels characterized by an extra drastic decrease of manganese and silicon contents. Their higher cost in comparison to “clean” steels leads to concern above which temperature they must be considered as mandatory for resisting aging embrittlement in operation. 3.5NiCrMoV “clean” steel samples (Mn = 0.30 pct; Si = 0.10 pct) were aged at 300 °C, 350 °C, and 400 °C for 10,000 hours up to 30,000 hours. No embrittlement results from aging at 300 °C and 350 °C, but holding at 400 °C is highly detrimental. Auger spectroscopy confirms that, when aging at 400 °C, phosphorus is the main embrittling trace element. It is suggested that grain boundary embrittlement is associated with the building of a layer that contains, on the one hand, Ni and P and, on the other hand, Mo and Cr. Head of the Testing and Head of the Testing and Head of the Testing and