Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “longevity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69Linked to original sources
PubMed2002

Formation and longevity of idarubicin-induced DNA topoisomerase II cleavable complexes in K562 human leukaemia cells.

Idarubicin (IDA) is an anthracycline used during treatment of acute myelogenous leukaemia (AML) and is clinically important because of its potency and lipophilicity (compared to the related compounds daunorubicin and doxorubicin). These drugs target DNA topoisomerase II (topo II), a nuclear enzyme that regulates DNA topology. Topo II poisoning leads to the trapping of an intermediate in the enzyme's cycle termed the "cleavable complex." This study aims to increase understanding of drug interactions by use of the "TARDIS" (trapped in agarose DNA immunostaining) assay to measure drug-induced topo II cleavable complexes in individual cells treated with anthracyclines. Mammalian cells contain two isoforms of topo II (alpha and beta) and the TARDIS assay enables visualisation of isoform-specific complexes. Drug-treated cells were embedded in agarose, lysed and incubated with anti-topo II antibodies to microscopically detect topo IIalpha or beta complexes. Results for K562 cells (at clinically relevant concentrations) showed that IDA and idarubicinol, its metabolite, formed mainly topo IIalpha cleavable complexes, the level of which decreases at doses > 1 microM for IDA. Our data suggest that this decrease is due to catalytic inhibition by IDA at these doses. Doxorubicin formed low levels of topo IIalpha complexes and negligible topo IIbeta complexes. In cytotoxicity studies, IDA and idarubicinol were equipotent, but both were more potent than daunorubicin and doxorubicin. We showed for the first time that there was a persistent increase in levels of topo IIalpha cleavable complexes after removal of IDA, suggesting that its greater effectiveness may be associated with both the longevity and high levels of these complexes.

Antibiotics, Antineoplastic↗
PubMed2001

Oxidative stress, aging and longevity in Drosophila melanogaster.

Free radicals produced during normal metabolism cause damage to macromolecules. The free radical theory of aging proposes that the organism is unable to repair all of them and that, with time, unrepaired damages accumulate and put the organism at risk: in other words, free radicals provoke aging and death. This article reviews both the results of adding antioxidants to food on longevity in Drosophila melanogaster, as well as the studies on antioxidant enzymes (inactivation in vivo, null mutants, overexpression). It is concluded that antioxidant enzymes are probably poorly connected to the normal aging process, but they allow the organism to cope with stressful conditions.

Aging↗
PubMed1998

Effects of seminal plasma from cigarette smokers on sperm viability and longevity.

OBJECTIVE: To evaluate the effects of cigarette smoking on the ability of seminal plasma (SP) to maintain sperm viability. DESIGN: Clinical randomized study. Spermatozoa from cigarette smoking or nonsmoking subjects were reconstituted in SP from smokers and nonsmokers and in modified Ham's F-10 medium, followed by sperm quality assessment during a 48-hour incubation period. SETTING: Andrology Institute of Lexington, Lexington, Kentucky. PATIENT(S): Twenty men who had been smoking cigarettes for longer than 3 years (30 cigarettes per day or more) and 20 nonsmokers participated in this study. MAIN OUTCOME MEASURE(S): Improvement in sperm viability by removal of SP--and associated detrimental factors present in the SP--from smoker subjects. RESULT(S): The results obtained indicate that the quality of spermatozoa obtained from nonsmokers was superior to that of smokers. The SP from the two patient groups had a definite effect on their respective sperm quality, i.e., beneficial effects for the nonsmokers, detrimental effects for the smokers. Exposure of spermatozoa from the nonsmokers to SP from the smokers resulted in a significant reduction in sperm viability. However, exposure of spermatozoa from the smokers to SP from the nonsmokers or to Ham's F-10 medium yielded significant improvements in sperm viability. CONCLUSION(S): The detrimental effects of smokers' SP on nonsmokers' spermatozoa was prominent and a rather unique phenomenon. The results generated in this study could be of clinical significance since removal of smokers' SP and subsequent reconstitution and incubation in physiological media seems to enhance the viability, longevity, and possibly the fertilizing ability of these spermatozoa for use in various assisted reproductive technologies.

Adult↗
PubMed2001

Larval crowding in Drosophila melanogaster induces Hsp70 expression, and leads to increased adult longevity and adult thermal stress resistance.

In this study we show for the first time that moderate high larval density induces Hsp70 expression in Drosophila melanogaster larvae. Larval crowding led to both increased mean and maximal longevity in adults of both sexes. Two different measures of heat-stress resistance increased in adult flies developed at high density compared to flies developed at low density. The hardening-like effect of high larval density carried over to the adult life stage. The hardening memory (the period of increased resistance after hardening) was long compared to hardening of adult flies, and possibly lasts throughout life. The increase in resistance in adults following development at high larval density seemed not to be connected to Hsp70 itself, since Hsp70 expression level in adult flies after hardening was independent of whether larvae developed at low or high densities. More likely, Hsp70 may be one of many components of the stress response resulting in hardening.

Journal Article↗
PubMed1999

Reproductive performance and longevity of female European corn borer, Ostrinia nubilalis: effects of multiple mating, delay in mating, and adult feeding.

In a recent study on the pheromone-mating disruption of the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), we recorded a significant reduction in mating frequency, as well as a marked delay in mating in feral females captured in disruptant-treated fields. In order to be able to accurately interpret the results in terms of effective population control, the current study was undertaken on the effects of multiple matings and a delay in mating on reproductive performance. Female O. nubilalis that mated at least twice had significantly higher fecundity and fertility, compared with once-mated females. In addition, multiple-mated females deposited a significantly larger portion of their egg complement, relative to single-mated or unmated females. Females that experienced a 3-day delay in mating showed a significant reduction in fecundity compared with females that mated soon after emergence. A 1-week delay in mating resulted in a further reduction in fecundity and a near zero fertility. The effect of sugar feeding on reproduction was not significant. In general, unmated females lived longer than mated females, and sugar-fed mated females had a higher longevity than water-fed mated females.

Journal Article↗
PubMed1999

Aggregation density and longevity correlate with humidity in first-instar nymphs of the cockroach (Blattella germanica L., Dictyoptera).

Nymphs and adults of the German cockroach, Blattella germanica, tend to aggregate. The effect of six different relative humidities (RH) on the aggregation behaviour of groups of 30 first instars was tested. The results show that grouping is denser under lower RHs than under higher humidities. The mean interindividual distances (nearest neighbour distances) proved to be inversely proportional to saturation deficiency (SD). The effect of aggregation behaviour in regulating water loss by evaporation is discussed. Under deprivation of food and drinking water survival times of the nymphs depend on RH. For five humidity levels tested the longevity (defined as MT(50)) proved to be inversely proportional to SD. The correlation is best fitted by a hyperbola.

Journal Article↗
PubMed1994

Increased longevity of EF-1 alpha high-fidelity mutants in Podospora anserina.

Various translation initiation and elongation factors seem to participate in the control of the cellular proliferation and the ageing process in higher eukaryotes. Studies indicate that EF-1 alpha, one of the translation elongation factors, may be one of the major components involved. We here present the cloning of the filamentous fungus P. anserina EF-1 alpha encoding gene and show that strains bearing high fidelity mutations in the EF-1 alpha gene have a drastically increased longevity as well as an impairment in sporulation. This suggests that EF-1 alpha involved in the sexual and senescence processes in lower eukaryotes, through the control of translational errors.

Amino Acid Sequence↗
PubMed2000

Sponge homologue to human and yeast gene encoding the longevity assurance polypeptide: differential expression in telomerase-positive and telomerase-negative cells of Suberites domuncula.

Porifera show a characteristic Bauplan in spite of the fact that (almost) all cells are telomerase-positive and presumably provided with an unlimited potency for cell proliferation. Studies revealed that telomerase-positive cells can be triggered to telomerase-negative cells by dissociating them into single cells. Single cells from the demosponge Suberites domuncula, in contrast to cells present in primmorphs (a special form of cell aggregates), lack the property to proliferate and they undergo apoptosis. One gene, SDLAGL, was identified in primmorphs that showed high sequence similarity to the longevity assurance genes from other Metazoa. In single cells no transcripts of SDLAGL could be identified, while high expression was seen after re-aggregation of single cells and in proliferating cells of primmorphs. We concluded that SDLAGL is involved in the shift of telomerase-positive, proliferating cells to telomerase-negative, non-proliferating cells.

Amino Acid Sequence↗
PubMed2002

Growth hormone or insulin-like growth factor-I extends longevity of equine spermatozoa in vitro.

Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are both present in blood plasma and IGF-I has been measured in epididymal fluid and seminal plasma. This study was designed to investigate the direct effects of GH or IGF-I on the motility of mature equine spermatozoa in vitro. We compared the effects of one concentration (100 ng/ml) of recombinant bovine GH (rbGH) and recombinant human IGF-I (rhIGF-I) on motility and motion characteristics of equine spermatozoa over a 24 h period. Motility was maintained longer in spermatozoa treated with either rbGH or rhIGF-I during a 24 h period at room temperature (P < 0.05). Spermatozoa motion characteristics at time 0, 1, 2, 4, 6, 12 and 24 h for both rbGH and rhlGF-I were not significantly different from the respective controls. This study has shown that GH and IGF-I are effective in promoting the in vitro longevity of spermatozoa.

Animals↗
PubMed1998

Effect of different glycerol treatments on frozen-thawed dog sperm longevity and acrosomal integrity.

Four different concentrations of glycerol in a Tris-fructose-citric acid extender for frozen dog semen and the effects of adding glycerol at 37 degrees C or 4 degrees C to the extender were studied by monitoring the post-thaw sperm longevity and acrosomal integrity during incubation at 39 degrees C. In the first part of this study, ejaculates from 13 dogs were pooled and divided into 4 aliquots, which were centrifuged and the sperm pellets rediluted with a Tris-fructose-citric acid extender containing 2, 4, 6 and 8% (v/v) glycerol, respectively. Progressive motility by subjective estimation, live:dead spermatozoa ratio using eosin-nigrosin staining, and acrosomal integrity using phase contrast microscopy were evaluated before processing and at 0, 0.5, 1, 2 and 4 hours post-thawing incubating the semen samples in the dark at 39 degrees C. The experiment was performed using seven replicates and it was found that sperm motility and acrosomal integrity were superior following the use of 8% glycerol in the extender. In Experiment 2, 13 ejaculates from the same dogs used in the first experiment were pooled and divided into 3 aliquots, and an 8% glycerol diluent was added at 37 degrees C and 4 degrees C after 1 h of cooling or at 4 degrees C after 2 h of cooling, respectively. After freezing and thawing the same parameters as studied in the first experiment were assessed. The experiment was performed in 7 replicates, and no difference was found between treatments.

Acrosome↗
PubMed1992

Factors associated with career longevity in residency-trained emergency physicians.

STUDY OBJECTIVE: To test the hypothesis that residency-trained emergency physicians who left the practice of emergency medicine do not differ significantly from those who continue to practice. DESIGN: A retrospective cohort study using a mailed questionnaire. TYPE OF PARTICIPANTS: Eight hundred fifty-eight emergency medicine residency graduates from 1978 through 1982. METHODS: A mailed questionnaire was used to obtain data from the study population. Individuals who did not respond to the first mailing were sent a second survey six weeks later. A sample of 10% of nonrespondents was contacted by telephone and compared with respondents on five variables. Respondents were divided into physicians who continued to practice emergency medicine and those who had elected to leave the specialty. The variables used to compare the two groups included personal and professional demographics, career satisfaction, and satisfaction with training. chi 2, Fisher's exact t-test, and logistic regression were used to analyze the data with an a priori level of significance set at .05. MEASUREMENTS AND MAIN RESULTS: There were 539 complete responses for a response rate of 62.8%. No statistical differences between responders and nonresponders were identified. The ten-year survival rate of respondents was 84.9%. Those who left emergency medicine were less likely to be board certified in emergency medicine (P less than .001), were more likely to be board certified in another field (P = .001), were less likely to work with residents during their emergency medicine practice (P = .009), and were more likely to report an annual gross income of less than $100,000 per year (P less than .001). Emergency physicians who have left the field were less likely to report being satisfied or very satisfied with their initial choice of emergency medicine as a specialty (P = .001). There was no difference in satisfaction with the quality of emergency medicine residency training (P = .183). CONCLUSION: Career longevity of residency-trained emergency physicians has been greater than early predictions. Interactions with residents, higher income, satisfaction with training decision, and board certification in emergency medicine are variables associated with a higher retention rate.

Adult↗
PubMed2002

Longevity of neutralizing antibody levels in macaques vaccinated with Quil A-adjuvanted measles vaccine candidates.

Quil A-based candidate measles vaccines have been shown to be immunogenic and protective in cotton rats and macaques. Here we studied the longevity of protective VN antibody levels induced in macaques with one dose of measles virus (MV) iscom. Inactivated MV adjuvanted with iscom-matrix or with purified Quillaja saponin QA-22 were also tested. All animals developed high levels of VN antibody and MV-specific IFNgamma-producing cells. Especially the high VN antibody levels induced by the latter two preparations showed virtually no decrease during the 2-year follow-up. These highly promising candidate MV vaccines should now be tested in infant macaques in the presence or absence of passively transferred and/or maternally derived VN antibodies. In addition, the immunopathological safety of the constructs should be evaluated in the atypical measles model in rhesus macaques.

Adjuvants, Immunologic↗
PubMed1996

A prospective clinical evaluation of the longevity of resorbable sutures in oral mucosa.

A prospective, randomised and controlled clinical investigation was undertaken to evaluate the longevity of resorbable sutures in the oral environment. The sutures investigated were gut, polyglycolic acid and polyglactin 910, were of standard gauge and needle type, and were placed using a standard technique by trained clinicians. The sutures were monitored following apical surgery in 55 patients (110 sutures) and the median survival values were: gut - 4 days, polyglycolic acid - 15 days, polyglactin 910 - 28 days. These differences were highly statistically significant. A postal survey of 30 randomly selected oral and maxillofacial surgeons reveal most prefer to use resorbable sutures, with softgut the most popular choice. Most would like an ideal resorbable suture to last 5 to 14 days and in this respect none of the materials tested appears satisfactory.

Absorption↗
PubMed2003

Relations between Scots pine needle element concentrations and decreased needle longevity along pollution gradients.

Scots pine (Pinus sylvestris L.) shoots were sampled along transects near one urban pollution source and two smelters. Needle Mg, P and K concentrations decreased from the second to the fourth age class linearly with needle survival along the urban pollution gradient. Still, over 80% of the average concentration of these nutrients remained in the fourth needle age class. Decreased needle longevity was closely related to the increased heavy metal concentrations near the smelters. Near the urban pollution source, it was related to the increased annual needle mass and the increased needle nutrient concentrations. Decreased Mn accumulation along with needle age was detected near all pollution sources. Leaching of Mn from needles and especially from soil as a cause of decreased needle concentrations is discussed.

Air Pollutants↗
PubMed2003

The life course prospective design: an example of benefits and problems associated with study longevity.

Although the life course prospective study design has many benefits, and information from such studies is in increasing demand for scientific and policy purposes, it has potential inherent design problems associated with its longevity. These are in particular the fixed sample structure and the data collected in early life, which are each determined by the scientific principles of another time and the risk over time of increased sample loss and distortion through loss. The example of a national birth cohort in Britain, studied from birth so far to age 53 years is used to address these questions. Although the response rate is high, avoidable loss, which was low in childhood, increased in adulthood, and was highest in those in adverse socio-economic circumstances and those with low scores on childhood cognitive measures. Recent permanent refusal rate rises may be the result of better tracing and/or a response to increased requests for biological measurement. Nevertheless, the responding sample continues in most respects to be representative of the national population of a similar age. Consistency of response over the study's 20 data collections has been high. The size of the sample responding in adulthood is adequate for the study of the major costly diseases, and for the study of functional ageing and its precursors. This study's continuation has depended not only on scientific value but also policy relevance. Although the problems inherent in the prospective design are unavoidable they are not, in the study described, a barrier to scientific and policy value. That seems also likely in Britain's two later born national birth cohort studies that have continued into adulthood.

Adolescent↗
PubMed2003

The Kronos longevity research institute.

The Kronos Longevity Research Institute (KLRI), founded in Jan., 2000, is a Phoenix-based not-for-profit institution conducting clinical translational research aimed at early detection and prevention of age-related diseases and slowing or reversing the aging process. KLRI also provides education in biomedical gerontology for regional and national professional and lay communities. KLRI is privately funded, mainly by the Aurora Foundation. S. Mitchell Harman, M.D., Ph.D., founding Director and President is board-certified in internal medicine and endocrinology and a former section chief and acting clinical director of the National Institute on Aging, NIH, with an international reputation as a leader in the field of hormones and aging. Other professional staff are: a Clinical Director, Director of Exercise Sciences, Senior Scientist, and Clinical Study Coordinator. KLRI's facility includes a clinical study center (CSC), an exercise study center (ESC), and a molecular laboratory. Current research focuses on relationships among aging, endocrine function, oxidative stress, and sarcopenia. All research projects are pre-reviewed by KLRI's Scientific Advisory Board, a distinguished group of biomedical investigators. KLRI sponsors a series of bimonthly seminars in Phoenix and an annual two-day national symposium, with talks on biomedical gerontology presented by world-renowned experts. The institute has plans to double faculty, staff, and research activities by 2006, which will require new sources of funding. The aging demography of the first half of the century will make KLRI's research increasingly relevant to the population of the U.S. and the world.

Academies and Institutes↗
PubMed1987

Automatic implantable cardioverter-defibrillator: patient survival, battery longevity and shock delivery analysis.

The automatic implantable cardioverter-defibrillator (AICD) has been shown to reduce the mortality rate of patients with malignant ventricular tachyarrhythmias. This report describes experience with implantation of 36 automatic implantable cardioverter-defibrillators (AID-B and AID-BR models) in 22 persons over a 44 month patient follow-up period (mean 19.6 months). There were five deaths: two patients died suddenly 22 and 29 months, respectively, after their second implant, one died of congestive heart failure, one died of respiratory failure and one died of catheter sepsis. Although 11 (50%) of the 22 patients never received a countershock for a ventricular tachyarrhythmia and are still alive, the other 11 received one or more spontaneous countershocks. Nine patients (41%) experienced spurious shocks during the follow-up period. Assuming that the first shock for presumed ventricular tachyarrhythmia prevented death, the hypothetical cumulative survival of patients at 42 months would have been 34 +/- 14.1% in the absence of an automatic implantable cardioverter defibrillator rather than the actual survival rate of 59 +/- 16.8%. The cumulative device survival of the 36 AID-B units was 92 +/- 5.62% at 15 months but diminished to 37 +/- 14.4% by 20 months. No unit lasted longer than 22 months. There were 12 battery depletions. The number of shocks emitted did not influence unit longevity. The manufacturer's elective replacement indicator is of uncertain validity. Six units remained active 7 to 17 months after surpassing their replacement indicator. The automatic implantable cardioverter-defibrillator prolongs the life of many patients with otherwise intractable arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

Molecular mechanisms of yeast longevity.

The genetic analysis of yeast longevity has illuminated the underlying molecular mechanisms of aging that invoke the importance of metabolic regulation, genetic stability and stress resistance in determination of life span. The RAS genes have emerged as important modulators of life-maintenance processes and of life span itself.

Gene Expression Regulation, Fungal↗