Associations of light, moderate, and vigorous intensity physical activity with longevity. The Harvard Alumni Health Study.
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Physical activity is associated with better health; however, the optimal intensity of activity remains unclear. A total of 13,485 men (mean age, 57.5 years) from the Harvard Alumni Health Study reported their walking, stair climbing, and sports/recreation in 1977. Between 1977 and 1992, 2,539 died. After adjusting for the different activity components, distance walked and storeys climbed independently predicted longevity (p, trend = 0.004 and <0.001, respectively). Light activities (<4 multiples of resting metabolic rate (METs)) were not associated with reduced mortality rates, moderate activities (4-<6 METs) appeared somewhat beneficial, and vigorous activities (> or =6 METs) clearly predicted lower mortality rates (p, trend = 0.72, 0.07, and <0.001, respectively). These data provide some support for current recommendations that emphasize moderate intensity activity; they also clearly indicate a benefit of vigorous activity. (+info)
Longevity and the costs of reproduction in a historical human population.
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It has been argued that the priority that natural selection places on reproduction negatively affects other processes such as longevity and the problem posed by this trade-off underlies the disposable soma theory for the evolution of human ageing. Here we examine the relationship between reproduction and longevity in a historical human population (the Krummhorn, north-west Germany 1720-1870). In our initial analyses, we found no support for the hypothesized negative effects of reproduction on longevity: married women who remained childless lived no longer than women who reproduced and women who had few children lived no longer than women who had many children. However, more detailed analyses in relation to socio-economic class revealed that the extent to which reproduction has an effect on longevity is a function of the level of economic deprivation. We found that, when possible sources of confound were controlled for (e.g. duration of marriage and amount of time spent in fecund marriage), there is an increasingly strong relationship between longevity and reproduction with increasing poverty. (+info)
NOD/LtSz-Rag1null mice: an immunodeficient and radioresistant model for engraftment of human hematolymphoid cells, HIV infection, and adoptive transfer of NOD mouse diabetogenic T cells.
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Development of a small animal model for the in vivo study of human immunity and infectious disease remains an important goal, particularly for investigations of HIV vaccine development. NOD/Lt mice homozygous for the severe combined immunodeficiency (Prkdcscid) mutation readily support engraftment with high levels of human hematolymphoid cells. However, NOD/LtSz-scid mice are highly radiosensitive, have short life spans, and a small number develop functional lymphocytes with age. To overcome these limitations, we have backcrossed the null allele of the recombination-activating gene (Rag1) for 10 generations onto the NOD/LtSz strain background. Mice deficient in RAG1 activity are unable to initiate V(D)J recombination in Ig and TCR genes and lack functional T and B lymphocytes. NOD/LtSz-Rag1null mice have an increased mean life span compared with NOD/LtSz-scid mice due to a later onset of lymphoma development, are radioresistant, and lack serum Ig throughout life. NOD/LtSz-Rag1null mice were devoid of mature T or B cells. Cytotoxic assays demonstrated low NK cell activity. NOD/LtSz-Rag1null mice supported high levels of engraftment with human lymphoid cells and human hemopoietic stem cells. The engrafted human T cells were readily infected with HIV. Finally, NOD/LtSz-Rag1null recipients of adoptively transferred spleen cells from diabetic NOD/Lt+/+ mice rapidly developed diabetes. These data demonstrate the advantages of NOD/LtSz-Rag1null mice as a radiation and lymphoma-resistant model for long-term analyses of engrafted human hematolymphoid cells or diabetogenic NOD lymphoid cells. (+info)
Use of a treatment protocol in the management of community-acquired lower respiratory tract infection.
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The aim of the present study was to examine the impact of an antimicrobial prescribing protocol on clinical and economic outcome measures in hospitalized patients with community-acquired lower respiratory tract infection (LRTI). The study was performed as a prospective controlled clinical trial within the medical wards at Antrim Area Hospital, Northern Ireland. Data were collected on all hospitalized adult patients with a primary diagnosis of LRTI during the period December 1994 to February 1995 (normal hospital practice; control group; n = 112). After an LRTI management protocol (medical, microbiological and pharmacy staff) had been developed, all hospitalized adult patients with a primary diagnosis of LRTI over the period December 1995 to February 1996 formed the intervention group (treated according to the protocol; n = 115). The results showed a statistically significant impact of the protocol in terms of clinical and economic outcome measures. Patients treated using the algorithmic prescribing protocol had significant reductions in length of hospital stay (geometric mean 4.5 versus 9.2 days), iv drug administration (34.8% versus 61.6%), duration of iv therapy (geometric mean 2.1 versus 5.7 days) and treatment failures (7.8% versus 31.3%). Healthcare costs were also significantly reduced. The use of the protocol was a major factor in streamlining the prescribing of antimicrobial therapy for community-acquired LRTI and led to more cost-effective patient management. (+info)
Newer approaches in increasing life span.
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Based on ideal conditions technical life span of human kind is approximately 110-120 years. Although number of studies including calorie restriction and antiparkinsonism drug (deprenyl) have indicated increased life span in animals, it is premature to expect them to increase life span in man. However, current studies like activation of immune system with DHEA in man and anticipation of antioxidant therapy contributing to increased life span are encouraging. Practice of meditation particularly TM and balanced diet might be contributory. (+info)
Serum lipid concentrations and mean life span are modulated by dietary polyunsaturated fatty acids in the senescence-accelerated mouse.
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The senescence-accelerated mouse (SAMP8) is an animal model used in studies of aging. This study was undertaken to investigate the effects of dietary PUFA on longevity (Experiment 1) and serum lipid concentrations (Experiment 2) in SAMP8 mice. Male mice were fed either an (n-3) PUFA-rich (9 g/100 g perilla oil) or an (n-6) PUFA-rich (9 g/100 g safflower oil) diet beginning at 6 wk of age. Experiment 1: The groups did not differ in body weight gain, but those fed perilla oil had significantly lower scores of senescence relative to those fed safflower oil (P<0.05). The mean life span of mice fed perilla oil was 357+/-21 d and of those fed safflower oil, 426+/-24 d (P<0.05). Pathological studies revealed that the incidence of tumors was significantly lower in the perilla oil group than in the safflower oil group (P<0.05). Approximately half the mice fed perilla oil had died after 10 mo, and the direct causes closely connected with death could not be specified. Experiment 2: The serum total cholesterol, HDL cholesterol, triglyceride and phospholipid concentrations were significantly lower in the perilla oil group than in the safflower oil group (P<0.01). A marked decrease of serum HDL cholesterol and apolipoprotein A-II (ApoA-II)concentrations in advanced age were observed in the mice fed perilla oil (P<0.01). Ten-month-old mice fed perilla oil had a significantly greater ratio of apolipoprotein A-I (ApoA-I) to ApoA-II than those fed safflower oil. Separation of HDL subfractions revealed that the smaller HDL species were much more abundant than the larger HDL species in both dietary oil groups. These findings suggest that dietary (n-3) and (n-6) PUFA differ in their effects on serum lipid metabolism which may modulate the mean life span of SAMP8 mice fed each dietary oil. (+info)
Mediterranean diet and age with respect to overall survival in institutionalized, nonsmoking elderly people.
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BACKGROUND: In studies from Italy and Greece, a Mediterranean dietary pattern was shown to favorably affect life expectancy in the elderly population. This pattern is thought to reduce the risk of cancer in addition to being cardioprotective. OBJECTIVE: The objective of this study was to evaluate the interactive effects of the Mediterranean diet and age with respect to survival after controlling for several other variables that could be considered as confounders: age, sex, body mass index, albumin concentration, physical activity, self-assessment of health, and dieting in response to chronic conditions. DESIGN: This was a cohort study involving 161 nonsmoking elderly subjects (74 subjects aged <80 y and 87 subjects aged > or =80 y) living in Spain. The subjects were followed up for > or =9 y. Diet was assessed with a semiquantitative food-frequency questionnaire. RESULTS: A diet score based on 8 characteristics of the traditional diet in the Mediterranean region was associated with a significant reduction in overall mortality in elderly subjects aged <80 y but not in subjects aged > or =80 y. A unit increase in the diet score predicted a 31% reduction in mortality in subjects aged <80 y (95% CI: 7%, 57%). CONCLUSION: Efforts to promote adherence to the Mediterranean dietary pattern appear to be worthwhile in persons aged <80 y, in whom the diet predicts survival, but we do not have any available evidence that such a diet benefits subjects aged > or =80 y. (+info)
Mice lacking a CDK inhibitor, p57Kip2, exhibit skeletal abnormalities and growth retardation.
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p57Kip2, one of the cyclin-dependent kinase (CDK) inhibitors, has been suggested to be a tumor suppressor candidate. To elucidate its biological roles in mouse development and tumorigenesis, we created p57Kip2-deficient mice. The p57Kip2-deficient mice exhibited a cleft palate and defective bone formation resulting in severe dyspnea. Most of the p57Kip2-deficient mice died within 24 h after birth, while about 10% of them survived beyond the weaning period. All of the surviving mice showed severe growth retardation. The males showed immaturity of the testes, prostate and seminal vesicles, and the females showed vaginal atresia, immaturity of the uterus, and an increased number of atretic follicles. Although Yan et al. and Zhang et al. have already reported p57Kip2-deficient mice, they could not investigate the phenotypes of the surviving p57Kip2-deficient mice. Also, most of the symptoms of Beckwith-Wiedemann syndrome could not be reproduced in the mutant mice. Embryonic fibroblasts prepared from p57Kip2-deficient mice showed no differences in the proliferation rate and saturation density, suggesting that G1 arrest is largely independent of p57Kip2 function. Our results suggest that p57Kip2 plays a critical role in development, but do not support the hypothesis that the p57Kip2 gene is a tumor-suppressor gene or is responsible for Beckwith-Wiedemann syndrome. (+info)