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Long Lifespan (long + lifespan)
Selected AbstractsResidual rickets or osteomalacia: a case dating from the 16,18th centuries from Krosno Odrza,skie, PolandINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2009E. Haduch Abstract A skeleton from a 16,18th century burial site in Krosno Odrza,skie, Poland, was examined using classical morphological, metric and macroscopic palaeopathological observations, as well as radiography and tomography of the skull and long bones. A wide variety of the observed bone deformations probably occurred as a consequence of past rickets and/or osteomalacia, whose primary cause may also have been chronic renal failure. Preservation of the bones enables a discussion of the cause of such pathological changes. The subject under study appears to be a very interesting example of an individual whose skeleton shows advanced pathological alterations associated with the subject's vitamin D deficiency, overall health conditions and relatively long lifespan. Copyright © 2008 John Wiley & Sons, Ltd. [source] Ex vivo differentiation of umbilical cord blood progenitor cells in the presence of placental conditioned mediumJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2002Mihaela Chivu Abstract Hematopoetic stem cells (HSC) are the progenitors for the lympho-hematopoietic system, with long lifespan and high proliferation potential. Transplantation of HSC from bone marrow or peripheral blood represents a standard therapy in severe hematological conditions. A possible alternative source of HSC is the umbilical cord blood, prepared by various separation procedures followed by expansion in cultures supplemented with hematopoietic growth factors. In order to check the effects of placental conditioned medium (PCM) from placental cells culture upon viability of HSC, we added plasma, PCM, dimetil sulfoxyde or hemin in HSC cultures. Flow cytometry or direct scoring of solid cultures using CD45+, CD34+, CD71+ and CD14+ fluorescent-labeled monoclonal antibodies evaluated the effects upon cell proliferation and colony forming ability of HSC cultures, versus controls. PCM produced the highest proliferation, followed by plasma, DMSO and hemin. PCM improved the survival time and maintained a higher proportion of immature cells. PCM stimulates the differentiation towards myeloid lineage progenitor cells (>90% being CD45+), increasing the percentage of CD14+, granulocites /monocytes precursors. It is highly suggestive that PCM contains growth factors or cytokines, which regulate the development of HSC. Characterization of these factors is in progress. [source] Insulin-like signalling in neurons controls lifespan in C. elegansJOURNAL OF NEUROCHEMISTRY, Issue 2002C. A. Wolkow Insulin-like signalling controls C. elegans lifespan, development and metabolism. Mutations that weaken this insulin-like signalling pathway extend lifespan. Severe mutations abolishing insulin-like signalling cause animals to arrest development as dauer larvae, a larval form specialized for stress resistance and long-term survival. A number of the genes acting in this pathway have been cloned, including daf-2, which encodes a homolog of vertebrate insulin/IGF-I receptors, and age-1, encoding the C. elegans homolog of the PI(3)K p110 catalytic subunit. In order to identify cells from which insulin-like signalling controls lifespan and development, transgenic animals were constructed which possessed insulin-like signalling only in specific cell types. To achieve this, cell-type specific promoters were used to drive expression of daf-2 or age-1 cDNAs in daf-2(,/,) or age-1(,/,) backgrounds, respectively. By utilizing this strategy, we could restore wild-type daf-2 or age-1 activity only in cells that are capable of expressing each transgene. Restoring insulin-like signalling to the nervous system of daf-2 or age-1 mutants could rescue long lifespan. This result was specific for transgenes restoring insulin-like signalling to the nervous system. Expressing daf-2 or age-1 cDNAs from muscle- or intestinally-restricted promoters was insufficient to rescue lifespan. In contrast, age-1 and daf-2 expression in either neuronal or non-neuronal cell types rescued dauer larval arrest in the mutants. These findings demonstrate that insulin-like signalling pathways in the nervous system control C. elegans lifespan. [source] Incorporating Uncertainty into Demographic Modeling: Application to Shark Populations and Their ConservationCONSERVATION BIOLOGY, Issue 4 2002Enric Cortés I used age-structured life tables and Leslie matrices based on a prebreeding survey and a yearly time step applied only to females to model the demography of 41 populations from 38 species of sharks representing four orders and nine families. I used Monte Carlo simulation to reflect uncertainty in the estimates of demographic traits and to calculate population statistics and elasticities for these populations; I used correlation analysis to identify the demographic traits that explained most of the variation in population growth rates ( , ). The populations I examined fell along a continuum of life-history characteristics that can be linked to elasticity patterns. Sharks characterized by early age at maturity, short lifespan, and large litter size had high , values and short generation times, whereas sharks that mature late and have long lifespans and small litters have low , values and long generation times. Sharks at the "fast" end of the spectrum tended to have comparable adult and juvenile survival elasticities, whereas sharks at the "slow" end of the continuum had high juvenile survival elasticity and low age,zero survival ( or fertility ) elasticity. Ratios of adult survival to fertility elasticities and juvenile survival to fertility elasticities suggest that many of the populations studied do not possess the biological attributes necessary to restore , to its original level after moderate levels of exploitation. Elasticity analysis suggests that changes in juvenile survival would have the greatest effect on ,, and correlation analysis indicates that variation in juvenile survival, age at maturity, and reproduction account for most of the variation in ,. In general, combined results from elasticity and correlation analyses suggest that research, conservation, and management efforts should focus on these demographic traits. Resumen: Exploré los efectos de la incertidumbre en los caracteres demográficos en análisis demográficos de tiburones, un método no empleado con anterioridad para este taxón. Utilicé tablas de vida estructuradas por edades y matrices de Leslie basadas en evaluaciones pre-gestación y pasos de tiempo de un año aplicados solo a las hembras para modelar la demografía de 41 poblaciones de 38 especies de tiburones que representan cuatro órdenes y nueve familias. Utilicé la simulación de Monte Carlo para reflejar la incertidumbre en las estimaciones de caracteres demográficos y calcular las estadísticas y elasticidades poblacionales para estas poblaciones y el análisis de correlación para identificar los caracteres demográficos que explican la mayoría de la variación en las tasas de crecimiento poblacional ( , ). Las poblaciones examinadas caen dentro de un continuo de características de historias de vida que pueden estar vinculadas con los patrones de elasticidad. Los tiburones que maduran a temprana edad y tienen corta duración de vida y grupos grandes de crías tuvieron valores altos de , y tiempos generacionales cortos, mientras que los tiburones que maduran tarde y tienen una duración de vida larga y grupos pequeños de crías tienen valores bajos de , y tiempos generacionales largos. Los tiburones que se encuentran en el punto final "rápido" del espectro tendieron a tener elasticidades de supervivencia de adultos y juveniles comparables, mientras que los tiburones en el punto final "lento" del continuo tuvieron una alta elasticidad de supervivencia de juveniles y una baja elasticidad en supervivencia a la edad cero (o fertilidad ). Las proporciones de elasticidades de supervivencia de adultos y fertilidad y de elasticidades de supervivencia de juveniles y fertilidad sugieren que muchas de las poblaciones estudiadas no poseen los atributos biológicos necesarios para restaurar , a su nivel original después de niveles moderados de explotación. El análisis de elasticidad sugiere que en la supervivencia de juveniles se podría tener el efecto mayor de , y el análisis de correlación indica que la variación en la supervivencia de juveniles, la edad de maduración y reproducción explican la mayor parte de la variación en ,. En general, los resultados combinados de los análisis de elasticidad y correlación sugieren que los esfuerzos de investigación, conservación y manejo deberían enfocarse a estas características demográficas. [source] | ||||||||||