DEVELOPING WORLD BIOETHICS, Issue 1 2007
MICHAL ENGELMAN
ABSTRACT To date, bioethics and health policy scholarship has given little consideration to questions of aging and intergenerational justice in the developing world. Demographic changes are precipitating rapid population aging in developing nations, however, and ethical issues regarding older people's claim to scarce healthcare resources must be addressed. This paper posits that the traditional arguments about generational justice and age-based rationing of healthcare resources, which were developed primarily in more industrialized nations, fail to adequately address the unique challenges facing older persons in developing nations. Existing philosophical approaches to age-based resource allocation underemphasize the importance of older persons for developing countries and fail to adequately consider the rights and interests of older persons in these settings. Ultimately, the paper concludes that the most appropriate framework for thinking about generational justice in developing nations is a rights-based approach that allows for the interests of all age groups, including the oldest, to be considered in the determination of health resource allocation. [source]

CALORIE RESTRICTION AND AGING: A LIFE-HISTORY ANALYSIS

EVOLUTION, Issue 3 2000
Daryl P. Shanley
Abstract., The disposable soma theory suggests that aging occurs because natural selection favors a strategy in which fewer resources are invested in somatic maintenance than are necessary for indefinite survival. However, laboratory rodents on calorie-restricted diets have extended life spans and retarded aging. One hypothesis is that this is an adaptive response involving a shift of resources during short periods of famine away from reproduction and toward increased somatic maintenance. The potential benefit is that the animal gains an increased chance of survival with a reduced intrinsic rate of senescence, thereby permitting reproductive value to be preserved for when the famine is over. We describe a mathematical life-history model of dynamic resource allocation that tests this idea. Senescence is modeled as a change in state that depends on the resources allocated to maintenance. Individuals are assumed to allocate the available resources to maximize the total number of descendants. The model shows that the evolutionary hypothesis is plausible and identifies two factors, both likely to exist, that favor this conclusion. These factors are that survival of juveniles is reduced during periods of famine and that the organism needs to pay an energetic "overhead" before any litter of offspring can be produced. If neither of these conditions holds, there is no evolutionary advantage to be gained from switching extra resources to maintenance. The model provides a basis to evaluate whether the life-extending effects of calorie-restriction might apply in other species, including humans. [source]

IS THERE AN ALTERNATIVE PROCESS TO AGING AND DEATH?

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2010
Ittyerah Tholath Peter MS
No abstract is available for this article. [source]

ASSOCIATION BETWEEN SERUM CARBOXYMETHYL-LYSINE, A DOMINANT ADVANCED GLYCATION END PRODUCT, AND ANEMIA IN ADULTS: THE BALTIMORE LONGITUDINAL STUDY OF AGING

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2008
Richard D. Semba MD
No abstract is available for this article. [source]

LAY CONCEPT OF AGING WELL: CROSS-CULTURAL COMPARISONS

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2008
Rocío Fernández-Ballesteros
No abstract is available for this article. [source]

CHANGE OF DIAGNOSES IN PROBABLE AND POSSIBLE MILD COGNITIVE IMPAIRMENT: THE ITALIAN LONGITUDINAL STUDY ON AGING

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2007
Vincenzo Solfrizzi MD
No abstract is available for this article. [source]

OLDER ADULTS' VIEWS OF "SUCCESSFUL AGING": COMPARISON OF OLDER JAPANESE AND AMERICANS

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2006
Kozo Matsubayashi MD
First page of article [source]

CHANGES IN MAJOR ANTIOXIDANT COMPOUNDS DURING AGING OF TRADITIONAL BALSAMIC VINEGAR

JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2010
ELENA VERZELLONI
ABSTRACT Traditional balsamic vinegar (TBV) shows antioxidant capacity that increases passing from cask 5, containing the youngest vinegar, to cask 1 containing the oldest vinegar. This increase in antioxidant capacity is a consequence of both the concentration of compounds already present and of new antioxidants formation and is positively related to the increase in the polyphenolic content and in the Maillard reaction/caramellization products. During TBV aging, some reactions involving flavonoids and tannins take place. Tannins can undergo acid-catalyzed cleavage of their interflavonoid bonds with subsequent condensation of other flavonoid molecules. In addition, the low pH, the decrease of the water content and the presence of aldehydes, may promote flavonoids polycondensation. These reactions explain the observed increase in polymeric phenolic compounds and the decrease in monomeric flavonoids. During TBV aging an increase in the browning index is observed as a consequence of the polycondensation reactions of flavonoids and of brown melanoidins accumulation. PRACTICAL APPLICATIONS Traditional balsamic vinegar is a potentially healthy seasoning with high antioxidant capacity that increases during the aging resulting in a product with a strong antioxidant capacity and rich in phenolic compounds such as phenolic acids, monomeric catechins, flavonols and tannins. It also contains other antioxidants such as melanoidins derived from the Maillard and caramelization reaction that occur during must boiling and traditional balsamic vinegar aging. Independently of their bioavailability, traditional balsamic vinegar can contribute to supply antioxidant molecules that play an important role in protecting the gastrointestinal tract itself against peroxidation, thereby limiting the formation of detrimental lipid degradation products. [source]

EFFECTS OF MUSCLE PROTEASES, ENDOGENOUS PROTEASE INHIBITORS AND MYOFIBRIL FRAGMENTATION ON POSTMORTEM AGING OF GOAT MEAT

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006
N.S. NAGARAJ
ABSTRACT The present study was conducted to evaluate the extent of postmortem proteolysis in longissimus dorsi, biceps femoris, semimembranosus and semitendinosus goat muscles on postmortem aging at an ambient (27C) temperature. The activities of calpains and calpastatin were determined after separation on a (diethylamino)ethyl,Sephacel column (Sigma, St. Louis, MO) and cathepsin (B, B + L and H) by carboxymethyl,Sepharose column (Sigma). The results showed that the decrease in calpain I and calpastatin activities was significantly higher than that of calpain II. Cathepsin B, B + L, H and cystatin were found to fall by 30,80% after 12 h, whereas cathepsin D decreased significantly in all the muscles. The disappearance of titin 1 and nebulin, and the appearance of a 30-kDa component were confirmed by Western blot analysis. The appearance of the 30-kDa component reported here explains the time-induced structural changes of myofibrils. The Z-line degradation had occurred by 6 h postmortem. Cathepsins are not stable compared to calpains during postmortem aging, and both enzymes may play a significant role in the proteolysis of myofibrillar proteins at ambient temperature. [source]

INFLUENCE OF AROMA COMPOUNDS ON LARGE DEFORMATION PROPERTIES OF STARCH-BASED SYSTEMS DURING AGING

JOURNAL OF TEXTURE STUDIES, Issue 3 2001
G. ARVISENET
The effect of aroma compounds on the texture of gelled aqueous corn starch systems was studied by uniaxial compression during aging for 18 days. Three different types of behavior were observed, depending on the nature of the added aroma compound. Isoamyl acetate did not modify the measured parameters, compared with nonflavored products. Linalool, known for its ability to form inclusion complexes with amylose, modified the parameters which are usually considered to be governed by the rearrangement of amylose chains. Ethyl hexanoate modified the parameters depending mostly on amylopectin. These results suggest that the nature of the aroma compound may play a major role in interactions with starch. These interactions can be different from inclusion complexes involving amylose chains only, the latter being widely described by different authors. [source]

SERUM TESTOSTERONE IS ASSOCIATED WITH AGGRESSIVE PROSTATE CANCER IN OLDER MEN: RESULTS FROM THE BALTIMORE LONGITUDINAL STUDY OF AGING

BJU INTERNATIONAL, Issue 6 2010
Abraham Morgentaler
No abstract is available for this article. [source]

Oral Isotretinoin as Part of the Treatment of Cutaneous Aging

DERMATOLOGIC SURGERY, Issue 7 2000
Enrique Hernandez-Perez MD
Background. A number of drugs have been used to prevent aging changes. However, studies of oral isotretinoin, the commonly used acne drug, as an antiaging drug are lacking. Objective. To determine improvement in cutaneous aging utilizing oral isotretinoin combined with different procedures of facial rejuvenation. Methods. Sixty patients ranging in age from 35 to 65 years, in whom additional modalities of rejuvenation were also used, were randomly assigned to receive treatment with oral isotretinoin (10,20 mg three times a week for 2 months, group A). Their results were compared with 60 patients who had undergone the same surgical procedures but with no oral isotretinoin (group B). Results. All patients treated with oral isotretinoin noted improvement in wrinkles, thickness and color of the skin, size of pores, skin elasticity, tone, and reduction in pigmented lesions and mottled hyperpigmentation. A statistically significant difference was found in the improvement of group A (Wilcoxon test <0.01). Using minimal amounts of this drug, the side effects were practically negligible. Conclusion. Utilizing various procedures with oral isotretinoin allowed us to improve the effects of cutaneous aging. Our results using isotretinoin in these cases have been satisfactory. We believe that this is one of the first reports of the use of oral isotretinoin in intrinsic and photoaged skin. [source]

Natural Aging in Al-Mg-Si Alloys , A Process of Unexpected Complexity,

ADVANCED ENGINEERING MATERIALS, Issue 7 2010
John Banhart
The natural aging behavior of pure ternary Al-Mg-Si alloys is investigated by measuring hardness, electrical resistivity and positron lifetime, as well as carrying out thermal analysis and atom probe microscopy. It is found that several distinct temporal stages of natural aging can be distinguished in which one of these quantities shows a characteristic behavior and that these times coincide for many of these measurements. The rate of change in the measured data is correlated with proposed solute dynamics during natural aging for both aging that takes place prior to artificial aging (natural pre-aging) and after artificial underaging (natural secondary aging) heat treatments. Controlling factors for solute dynamics are discussed. [source]

Age-related changes in dopamine transporters and accumulation of 3-nitrotyrosine in rhesus monkey midbrain dopamine neurons: Relevance in selective neuronal vulnerability to degeneration

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2008
N. M. Kanaan
Abstract Aging is the strongest risk factor for developing Parkinson's disease (PD). There is a preferential loss of dopamine (DA) neurons in the ventral tier of the substantia nigra (vtSN) compared to the dorsal tier and ventral tegmental area (VTA) in PD. Examining age-related and region-specific differences in DA neurons represents a means of identifying factors potentially involved in vulnerability or resistance to degeneration. Nitrative stress is among the factors potentially underlying DA neuron degeneration. We studied the relationship between 3-nitrotyrosine (3NT; a marker of nitrative damage) and DA transporters [DA transporter (DAT) and vesicular monoamine transporter-2 (VMAT)] during aging in DA subregions of rhesus monkeys. The percentage of DA neurons containing 3NT increased significantly only in the vtSN with advancing age, and the vtSN had a greater percentage of 3NT-positive neurons when compared to the VTA. The relationship between 3NT and DA transporters was determined by measuring fluorescence intensity of 3NT, DAT and VMAT staining. 3NT intensity increased with advancing age in the vtSN. Increased DAT, VMAT and DAT/VMAT ratios were associated with increased 3NT in individual DA neurons. These results suggest nitrative damage accumulates in midbrain DA neurons with advancing age, an effect exacerbated in the vulnerable vtSN. The capacity of a DA neuron to accumulate more cytosolic DA, as inferred from DA transporter expression, is related to accumulation of nitrative damage. These findings are consistent with a role for aging-related accrual of nitrative damage in the selective vulnerability of vtSN neurons to degeneration in PD. [source]

Effects of Aging on Interfacial Microstructure and Reliability Between SnAgCu Solder and FeNi/Cu UBM,

ADVANCED ENGINEERING MATERIALS, Issue 6 2010
Qing-Sheng Zhu
Effects of thermal aging on the interfacial microstructure and reliability of the SnAgCu/FeNi-Cu joint are investigated. It is found that aging effects depends strongly on the temperature. Aging at low temperature, e.g., at 125,°C, a submicron meter thick FeSn2 IMC layer formed at the SnAgCu/FeNi-Cu interface during reflowing grows at a rate twenty times slower than the growth rate of the IMC at the SnAgCu/Cu interface. At high temperature, e.g., at 180,°C, the Cu element is found to diffuse through FeNi layer to produce the (Cu, Ni)6Sn5 IMC and this IMC layer grows even faster than the IMC at the SnAgCu/Cu interface. Solder ball shear test results show that the SnAgCu/FeNi-Cu joint has a comparable strength to the SnAgCu/Cu joint after reflowing, and the strength drop after aging at 125,°C is less than that of the SnAgCu/Cu joint. However, after aging at 180,°C, the strength of the SnAgCu/FeNi-Cu joint is degraded to a low value, along with a shift in failure mode from the solder fracture to the brittle intermetallics fracture. [source]

Load-bearing capacity of all-ceramic three-unit fixed partial dentures with different computer-aided design (CAD)/computer-aided manufacturing (CAM) fabricated framework materials

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2008
Florian Beuer
The purpose of this in vitro study was to compare the load-bearing capacity of posterior three-unit fixed dental prostheses (FDP) produced with three different all-ceramic framework materials: glass-infiltrated alumina (ICA), glass-infiltrated alumina strengthened with zirconia (ICZ), and yttria-stabilized polycrystalline zirconia (YZ). Additionally, the influence on aging of mechanical cyclic fatigue loading and thermal cycling in water were evaluated. A total of 20 frameworks each were fabricated from ICA, ICZ, and YZ by a computer-aided design (CAD)/computer-aided manufacturing (CAM) system. The framework designs were identical for all specimens. All frameworks were veneered with porcelain and cemented with glass,ionomer. Prior to fracture testing, 10 FDP of each experimental group were subjected to thermal and mechanical cycling. Additionally, fractographic analysis was performed. Statistical analysis showed that FDP made from YZ had significantly higher load to failure, whereas no difference was found between the other two materials. Aging did not have a significant effect on the fracture load. [source]

Designing Ultrahigh Strength Steels with Good Ductility by Combining Transformation Induced Plasticity and Martensite Aging

ADVANCED ENGINEERING MATERIALS, Issue 7 2009
Dierk Raabe
We present results on precipitation hardened ductile high strength maraging-TRIP steels with up to 1.5 GPa strength and good ductility. The alloys have low carbon content (0.01 wt% C), 9,15 wt% Mn, and additions of Ni, Ti, and Mo (1,2 wt%) for precipitation. Martensite aging leads to a surprising simultaneous increase in strength and total elongation for samples with 9 wt% Mn and 12 wt% Mn. [source]

Aging of transformer insulating materials under selective conditions

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2007
I. Fofana
Abstract In today's economic climate, it is important to know the condition, by means of suitable diagnostic tests, of the oil impregnated paper usable as primary insulation in equipment such as transformers, switchgear, bushings, cables, and their accessories. The aim of this paper is regarded as a main task to study the parameters that mostly influence the ageing process of oil/paper insulation used in transformers with preset moisture levels. A comparison is made between the performances of cellulose and Aramid papers. It is shown that Aramid paper is much less sensitive to water than cellulose paper. However, the addition of air (oxygen), via acid formation and oxidation in the oil, has a direct influence on the increase of the loss factor for both papers. The catalysts, that represent the metallic components in the transformer, accelerate the ageing process of the cellulose papers, while no influence on the ageing process of Aramid was observed. Oil ageing without a solid partner is insignificantly influenced by water, but accelerated by air-oxygen, via the moisture and acid formation, and oxidation processes. A direct influence on the increase of the loss factor and the decrease of electric strength particularly at low temperatures is to be noted. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Novel modelling of residual operating time of transformer oil

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2003
M. A. A. Wahab
This paper presents techniques developed to accurately model the characteristics of transformer oil for the purpose of predicting the effect of aging on these characteristics. Aging causes some of the transformer oil characteristics to violate the internationally specified limits. The purpose of this simulation is to develop alternative techniques to predict the operating time after which these characteristics would violate the limits. The results obtained from monitoring of twenty in-service power transformers for long period of operating time up to ten years have been implemented in developing the proposed models. The physical, chemical and electrical characteristics have been determined periodically by internationally specified testing methods. The patterns of violation sequence of the standard limits, against operating time, by different transformer oil characteristics have been revealed and the most common pattern has been determined. The definition of residual operating time (trot) of the different transformer oil characteristics has been introduced. The choice of transformer oil breakdown voltage trot to represent that of the transformer oil characteristics has been justified. Modelling of trot as a function of transformer oil breakdown voltage, total acidity and water content by multiple-linear regression has been proposed and verified. Also, polynomial regression model of trot as a function only of transformer oil breakdown voltage has been given. The accuracy and applicability of these models and the different modelling techniques have been discussed and proved. [source]

Expression of psoriasis-associated fatty acid-binding protein in senescent human dermal microvascular endothelial cells

EXPERIMENTAL DERMATOLOGY, Issue 9 2004
Moon Kyung Ha
Abstract:, Aging is associated with the progressive pathophysiologic modification of endothelial cells. In vitro endothelial cell senescence is accompanied by proliferative activity failure and by perturbations in gene and protein expressions. Moreover, this cellular senescence in culture has been proposed to reflect processes that occur in aging organisms. In order to observe the changing patterns of protein expression in senescent human dermal microvascular endothelial cells (HDMECs), proteins obtained from both early- and late-passaged HDMECs were separated by two-dimensional electrophoresis, visualized by silver staining, and quantified by image processing. Proteins of interest were extracted by in-gel digestion with trypsin and quantified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), by searching the National Center for Biotechnology Information protein-sequence database. More than 2000 spots were detected by 2D electrophoresis within a linear pH range of 3,10. Twenty-two major differentially expressed spots were observed in serially passaged HDMECs and identified with high confidence by MALDI-TOF-MS. One of these spots was found to be a 14,15 kDa psoriasis-associated fatty acid-binding protein (PA-FABP) with high affinity for long-chain fatty acids. The expression of PA-FABP was confirmed to be elevated in senescent HDMECs (passage 20) by fluorescence-activated cell sorting (FACS), confocal laser microscopy, and by immunohistochemistry in aged human skin tissue. Our results suggest that the overexpression of FABP in cultured senescent HDMECs is closely related to skin aging. [source]

Domain Engineering of Lead-Free Li-Modified (K,Na)NbO3 Polycrystals with Highly Enhanced Piezoelectricity

ADVANCED FUNCTIONAL MATERIALS, Issue 12 2010
Ke Wang
Abstract Aging and re-poling induced enhancement of piezoelectricity are found in (K,Na)NbO3 (KNN)-based lead-free piezoelectric ceramics. For a compositionally optimized Li-doped composition, its piezoelectric coefficient d33 can be increased up to 324 pC N,1 even from a considerably high value (190 pC N,1) by means of a re-poling treatment after room-temperature aging. Such a high d33 value is only reachable in KNN ceramics with complicated modifications using Ta and Sb dopants. High-angle X-ray diffraction analysis reveals apparent changes in the crystallographic orientations related to a 90° domain switching before and after the aging and re-poling process. A possible mechanism considering both defect migration and rotation of spontaneous polarization explains the experimental results. The present study provides a general approach towards piezoelectric response enhancement in KNN-based piezoelectric ceramics. [source]

Late-life insomnia: A review

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2009
Arne Fetveit
Aging is associated with substantial changes in sleep patterns, which are almost always negative in nature. Typical findings in the elderly include a reduction in the deeper stages of sleep and a profound increase in the fragmentation of nighttime sleep by periods of wakefulness. The prevalence of specific sleep disorders increases with age, such as a phase advance in the normal circadian sleep cycle, restless legs syndrome, and obstructive sleep apnea, which is increasingly seen among older individuals and is significantly associated with cardio- and cerebrovascular disease as well as cognitive impairment. Elderly patients with sleep disturbances are often considered difficult to treat; yet, they are among the groups with the greatest need of treatment. Management of sleep disturbances begins with recognition and adequate assessment. Hypnotic drugs have clearly been shown to improve subjective and objective sleep measures in short-term situations, but their role in chronic insomnia still remains to be further defined by research evidence. Non-pharmacological treatments, particularly stimulus control and sleep restriction, are effective for conditioned aspects of insomnia and are associated with a stable, long-term improvement in sleep. This review delineates the common causes of disordered sleep in older individuals, and effective diagnostic approaches and treatments for these conditions. [source]

Impaired efflux of cholesterol from aged cells and its molecular mechanism: A basis for age-related enhancement of atherosclerosis

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2007
Shizuya Yamashita
Aging is one of the risk factors for atherosclerotic cardiovascular diseases, however, its molecular mechanism is currently unknown. Many types of cells in the atherosclerotic lesions are considered to have various biological abnormalities such as impaired lipid homeostasis and slow cell proliferation, which may be related to senescence at cellular levels. One of the common characteristics of senescent cells in vitro is the alteration of actin cytoskeletons, which were reported to be involved in the intracellular transport of lipids. Cholesterol efflux from the cells is the initial step of reverse cholesterol transport, a major protective system against atherosclerosis. Recently, we demonstrated that Cdc42, a member of the Rho -GTPase family, might be crucial for cellular lipid transport and cholesterol efflux based upon studies of Tangier cells that are deficient in ABCA1 gene. In the current review, we also indicate that the expression of Cdc42 is decreased in the cells from aged subjects in close association with the retarded intracellular lipid transport. Furthermore, the Cdc42 expression is reduced by culturing fibroblasts in vitro for a long duration. Werner syndrome (WS) is characterized by the early onset of senescent phenotypes including premature atherosclerotic cardiovascular diseases, although the underlying molecular mechanism for the enhanced atherosclerosis has not been fully understood yet. We examined the intracellular lipid transport and cholesterol efflux and the expression levels of cholesterol efflux-related molecules in skin fibroblasts obtained from patients with WS. Cholesterol efflux was markedly reduced in the WS fibroblasts in association with an increased cellular cholesterol content. Fluorescent recovery after photobleaching technique revealed that intracellular lipid transport around Golgi apparatus was markedly reduced when using a C6-NBD-ceramide as a tracer. Cdc42 protein and its guanosine 5,-triphosphate-bound active form were markedly reduced in the WS fibroblasts. The adenovirus-mediated complementation of wild-type Cdc42 corrected the impaired cholesterol efflux, intracellular lipid transport and cellular cholesterol levels in the WS fibroblasts. These data indicate that the reduced expression of Cdc42 might be responsible for the abnormal lipid transport, which in turn might be related to the accelerated cardiovascular manifestations in WS patients. The current review focuses on the impaired efflux of cholesterol from aged cells and its molecular mechanism as a basis for age-related enhancement of atherosclerosis. [source]

Aging per se does not influence postprandial glucose levels in type 2 diabetes

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2005
Yumiko Magata
Background: It is well known that postprandial glucose increases with aging in non-diabetic subjects. The question we addressed is whether elderly type 2 diabetic patients with definite fasting hyperglycemia (, 126 mg/dL) also display increased postprandial hyperglycemia relative to their younger counterparts. Methods: Diurnal plasma glucose profiles were measured in 162 overt type 2 diabetic patients treated by diet alone (diet group) or with sulfonylureas as monotherapy (SU group). Plasma glucose concentrations were measured at 08.00 hours (before breakfast), 10.00, 12.00 (before lunch), 14.00, 18.00 (before dinner), 20.00, 24.00, 03.00, 06.00 and 08.00 hours the next morning. The postprandial glucose area under the curve (AUC) from 08.00 to 24.00 hours was calculated above the baseline level equal to the 08.00-hours plasma glucose value, and the relationships with clinical variables, including age, were assessed. Results: There were no differences in diurnal plasma glucose profiles between the middle-aged (< 65 years) and elderly (, 65 years) groups either the diet group or the SU group. Univariate analysis showed that the postprandial glucose area under the curve was related to the 08:00-hours plasma glucose value (R = 0.583, P < 0.001) in the diet alone group and to the duration of diabetes (R = 0.220, P < 0.05), SU dose (R = 0.330, P = 0.001) and urine CPR (R = ,0.229, P < 0.05) in the SU group. In multivariate analysis, postprandial glucose area under the curve was only related to 08.00 hours plasma glucose value in the diet group (R2 of the model = 0.340, P < 0.001) and to the SU dose in SU group (R2 of the model = 0.145, P < 0.001). Conclusion: These results suggest that aging, per se, does not influence postprandial glucose levels in overt type 2 diabetic patients. [source]

Capturing the power of academic medicine to enhance health and health care of the elderly in the USA

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 1 2004
William R Hazzard
As in Japan, the US population is aging progressively, a trend that will challenge the health-care system to provide for the chronic, multiple and complex needs of its elderly citizens. and as in Japan, the US academic health enterprise has only belatedly mounted a response to that challenge. Herein is reviewed a quarter of a century of the author's personal experience in developing new programs in gerontology and geriatric medicine from a base in the Department of Internal Medicine at three US academic health centers (AHC): The University of Washington (as Division Head), Johns Hopkins University (as Vice-Chair), and Wake Forest University (as Chair). Rather than to build a program from a new department of geriatrics, this strategy was chosen to capture the power and resources of the department of internal medicine, the largest university department, to ,gerontologize' the institution, beginning with general internal medicine and all of the medical subspecialties (the approach also chosen to date at all but a handful of US AHC). The keystone of success at each institution has been careful faculty development through fellowship training in clinical geriatrics, education and research. Over the same interval major national progress has occurred, including expanded research and training at the National Institute on Aging and the Department of Veterans Affairs, and accreditation of more than 100 fellowship programs for training and certification of geriatricians. However, less than 1% of US medical graduates elect to pursue such training. Hence such geriatricians will remain concentrated at AHC, and most future geriatric care in the USA will be provided by a broad array of specialists, who will be educated and trained in geriatrics by these academic geriatricians. [source]

Pension Reform, Capital Markets and the Rate of Return

GERMAN ECONOMIC REVIEW, Issue 2 2003
Axel Börsch-Supan
Aging; pension reform; rates of return Abstract. This paper discusses the consequences of population aging and a fundamental pension reform , that is, a shift towards more pre-funding , for capital markets in Germany. We use a stylized closed-economy, overlapping-generations model to compare the effects of the recent German pension reform with those of a more decisive reform that would freeze the current pay-as-you-go contribution rate and thus result in a larger funded component of the pension system. We predict rates of return to capital under both reform scenarios over a long horizon, taking demographic projections as given. Our main finding is that the future decrease in the rate of return is much smaller than often claimed in the public debate. Our simulations show that the capital stock will decrease once the baby-boom generations enter retirement, even if there were no fundamental pension reform. The corresponding decrease in the rate of return, the direct effect of population aging, is around 0.7 percentage points. While the capital market effects of the recent German pension reform are marginal, the rate of return to capital would decrease by an additional 0.5 percentage points under the more decisive reform proposal. [source]

The impact of diabetes on employment: genetic IVs in a bivariate probit

HEALTH ECONOMICS, Issue 5 2005
H. Shelton Brown III
Abstract Diabetes has been shown to have a detrimental impact on employment and labor market productivity, which results in lost work days and higher mortality/disability. This study utilizes data from the Border Epidemiologic Study on Aging to analyze the endogeneity of diabetes in an employment model. We use family history of diabetes as genetic instrumental variables. We show that assuming that diabetes is an exogenous variable results in an overestimate (underestimate) of the negative impact of diabetes on female (male) employment. Our results are particularly relevant in the case of populations where genetic predisposition has an important role in the etiology of diabetes. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Aging does not reduce the hepatocyte proliferative response of mice to the primary mitogen TCPOBOP

HEPATOLOGY, Issue 4 2004
Giovanna M. Ledda-Columbano
It has been shown that the magnitude of DNA synthesis and the time at which maximal DNA synthesis occurs after two-thirds partial hepatectomy (PH) is greatly reduced in the liver of aged rodents compared to young animals. This reduction could represent an intrinsic defect in proliferation or a more specialized change in the response to PH. We therefore evaluated the proliferative capacity of hepatocytes in aged animals, following treatment with primary liver mitogens. We show that treatment of 12-month-old CD-1 mice with the hepatomitogen 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) caused an increase in hepatocyte proliferation similar to that seen in young (8-week-old) mice. The labeling index was 82% in the livers of aged mice versus 76% in young animals. Histological observation demonstrated that the number of hepatocytes entering mitoses was similar in both groups; the mitotic indices were 2.5 per thousand and 2.7 per thousand, respectively. Additional experiments showed that the timing of DNA synthesis and M phase were nearly identical in both aged and young mice. Stimulation of hepatocyte DNA synthesis was associated with increased expression of several cell cycle-associated proteins (cyclin D1, cyclin A, cyclin B1, E2F, pRb, and p107); all were comparable in aged mice and young mice. TCPOBOP treatment also increased expression of the Forkhead Box transcription factor m1b (Foxm 1b) to a similar degree in both groups. In conclusion, hepatocytes retain their proliferative capacity in old age despite impaired liver regeneration. These findings suggest that therapeutic use of mitogens would alleviate the reduction in hepatocyte proliferation observed in the elderly. (Hepatology 2000;40:981,988). [source]

Aging and the interaction of sensory cortical function and structure

HUMAN BRAIN MAPPING, Issue 1 2009
Ann M. Peiffer
Abstract Even the healthiest older adults experience changes in cognitive and sensory function. Studies show that older adults have reduced neural responses to sensory information. However, it is well known that sensory systems do not act in isolation but function cooperatively to either enhance or suppress neural responses to individual environmental stimuli. Very little research has been dedicated to understanding how aging affects the interactions between sensory systems, especially cross-modal deactivations or the ability of one sensory system (e.g., audition) to suppress the neural responses in another sensory system cortex (e.g., vision). Such cross-modal interactions have been implicated in attentional shifts between sensory modalities and could account for increased distractibility in older adults. To assess age-related changes in cross-modal deactivations, functional MRI studies were performed in 61 adults between 18 and 80 years old during simple auditory and visual discrimination tasks. Results within visual cortex confirmed previous findings of decreased responses to visual stimuli for older adults. Age-related changes in the visual cortical response to auditory stimuli were, however, much more complex and suggested an alteration with age in the functional interactions between the senses. Ventral visual cortical regions exhibited cross-modal deactivations in younger but not older adults, whereas more dorsal aspects of visual cortex were suppressed in older but not younger adults. These differences in deactivation also remained after adjusting for age-related reductions in brain volume of sensory cortex. Thus, functional differences in cortical activity between older and younger adults cannot solely be accounted for by differences in gray matter volume. Hum Brain Mapp 2009. © 2007 Wiley-Liss, Inc. [source]

A forward application of age associated gray and white matter networks,

HUMAN BRAIN MAPPING, Issue 10 2008
Adam M. Brickman
Abstract To capture patterns of normal age-associated atrophy, we previously used a multivariate statistical approach applied to voxel based morphometry that identified age-associated gray and white matter covariance networks (Brickman et al. [2007]: Neurobiol Aging 28:284,295). The current study sought to examine the stability of these patterns by forward applying the identified networks to an independent sample of neurologically healthy younger and older adults. Forty-two younger and 35 older adults were imaged with standard high-resolution structural magnetic resonance imaging. Individual images were spatially normalized and segmented into gray and white matter. Covariance patterns that were previously identified with scaled subprofile model analyses were prospectively applied to the current sample to identify to what degree the age-associated patterns were manifested. Older individuals were also assessed with a modified version of the Mini Mental State Examination (mMMSE). Gray matter covariance pattern expression discriminated between younger and older participants with high optimal sensitivity (100%) and specificity (90.5%). While the two groups differed in the degree of white matter pattern expression (t (75) = 5.26, P < 0.001), classification based on white matter expression was relatively low (sensitivity = 80% and specificity = 61.9%). Among older adults, chronological age was significantly associated with increased gray matter pattern expression (r (32) = 0.591, P < 0.001) but not with performance on the mMMSE (r (31) = ,0.314, P = 0.085). However, gray matter pattern expression was significantly associated with performance on the mMMSE (r (31) = ,0.405, P = 0.024). The findings suggest that the previously derived age-associated covariance pattern for gray matter is reliable and may provide information that is more functionally meaningful than chronological age. Hum Brain Mapp 2008. © 2007 Wiley-Liss, Inc. [source]