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11.
Salminen A Kauppinen A Suuronen T Kaarniranta K 《BioEssays : news and reviews in molecular, cellular and developmental biology》2008,30(10):939-942
The aging process involves changes in immune regulation, i.e. adaptive immunity declines whereas innate immunity becomes activated. NF-kappaB signaling is the master regulator of the both immune systems. Two recent articles highlight the role of the NF-kappaB system in aging and immune responses. Adler et al showed that the NF-kappaB binding domain is the genetic regulatory motif which is most strongly associated with the aging process. Kwon et al studying HIV-1 infection and subsequent immune deficiency process demonstrated that HIV-1 Tat protein binds to SIRT1 protein, a well-known longevity factor, and inhibits the SIRT1-mediated deacetylation of the p65 component of the NF-kappaB complex. As a consequence, the transactivation efficiency of the NF-kappaB factor was greatly potentiated, leading to the activation of immune system and later to the decline of adaptive immunity. These observations support the scenario where immune responses and aging process can be enforced by the potentiation of NF-kappaB transactivation efficiency. Longevity factors, such as SIRT1 and its activators, might regulate the efficiency of the NF-kappaB signaling, the major outcome of which is inflamm-aging via proinflammatory responses. 相似文献
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Antero Järvinen 《Ecography》1989,12(2):152-162
Dynamics and performance of established individuals of Ranunculus glacialis at the time of peak flowering were monitored in a mountain area in Finnish Lapland for five years (1982–1986). The plants reproduced only sexually, and their spatial distribution in 40 1-m2 quadrats was clumped. During the study period the mean density rose from 8.5 to 10.3 individuals m−2 . The mean annual growth rate and birth rate of the population was 4% and 8.5%, respectively. The mean annual death rate of established individuals was 3.7%. The estimated mean life expectancy of an established individual was 27 yr. Death rate per quadrat was positively related to R. glacialis density, but birth rate per quadrat was negatively related to the percentage cover of stones per quadrat. High R. glacialis density per quadrat had negative effects, but high nitrogen availability had positive effects on the number of leaves per individual. An important factor reducing flowering was small rodent herbivory. In the same genets, the correlation between the number of leaves per individual in year t and the number of flowers per individual in year t+4 was significant. The below-ground biomass of R. glacialis comprised about 70% of the total biomass, and there was a close correlation between the above- and the below-ground biomass of an individual. The individuals flowered abundantly each year and produced a great number of small-sized achenes. 相似文献
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Tapio Eeva Suvi Ruuskanen Juha-Pekka Salminen Eugen Belskii Antero J?rvinen Anvar Kerimov Erkki Korpim?ki Indrikis Krams Juan Moreno Chiara Morosinotto Raivo M?nd Markku Orell Anna Qvarnstr?m Heli Siitari Fred M. Slater Vallo Tilgar Marcel E. Visser Wolfgang Winkel Herwig Zang Toni Laaksonen 《Oecologia》2011,165(2):277-287
Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female??s diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations. To assess whether yolk carotenoid concentrations or carotenoid profiles show any large-scale geographical trends or differences among habitats, we collected yolk samples from 16 European populations of the pied flycatcher, Ficedula hypoleuca. We found that the concentrations and proportions of lutein and some other xanthophylls in the egg yolks decreased from Central Europe northwards. The most southern population (which is also the one found at the highest altitude) also showed relatively low carotenoid levels. Concentrations of ??-carotene and zeaxanthin did not show any obvious geographical gradients. Egg yolks also contained proportionally more lutein and other xanthophylls in deciduous than in mixed or coniferous habitats. We suggest that latitudinal gradients in lutein and xanthophylls reflect the lower availability of lutein-rich food items in the northern F. hypoleuca populations and in montane southern populations, which start egg-laying earlier relative to tree phenology than the Central European populations. Similarly, among-habitat variation is likely to reflect the better availability of lutein-rich food in deciduous forests. Our study is the first to indicate that the concentration and profile of yolk carotenoids may show large-scale spatial variation among populations in different parts of the species?? geographical range. Further studies are needed to test the fitness effects of this geographical variation. 相似文献
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Lennart Saari Erkki Pulliainen Olavi Hildén Antero J?rvinen Ilmari M?kisalo 《Journal of Ornithology》1994,135(4):549-575
The breeding biology of the Siberian Tit was studied in several areas within the whole breeding range of this species in Finland. A total of about 920 nests came to our knowledge. The breeding densities exceeded 4 pairs/km2 in best habitats and the population decline since the 1940s has not been as marked as suspected. The onset of laying did not vary much between the study areas. The mean at Kuusamo (southern edge of the range) was 18 May, and 22 May at Kilpisjärvi where the environment is harshest. The mean clutch size was 7.94 with moderate geographic variation, but no clear geographical trends. No genuine second clutches have ever been recorded in the Siberian Tit. The breeding success (number of young fledging of number of eggs laid) varied between 60 and 87 % being highest at Kuusamo and lowest at Kilpisjärvi.
Zusammenfassung Die Brutbiologie der Lapplandmeise wird nach Untersuchungen in verschiedenen Gebieten ihres Areals in Finnland beschrieben. Ausgewertet werden Daten von insgesamt 920 Nestern. In den besten Habitaten ist mit einer Dichte über 4 Paaren/km2 zu rechnen; die Abnahme seit den 40er Jahren war offenbar nicht so stark wie bisher vermutet. Der Legebeginn variierte zwischen den Untersuchungsgebieten nicht sehr deutlich. Der Mittelwert fällt am Südrand des Areals bei Kuusamo auf den 18. Mai, bei Kilpisjärvi, dem rauhesten Gebiet, auf den 22. Die mittlere Gelegegröße betrug 7,9 Eier mit einer schwachen geographischen Variation, aber mit keinem deutlichen geographischen Trend. Sichere Zweitgelege wurden bis jetzt bei der Lapplandmeise nicht nachgewiesen. Der Bruterfolg (Zahl der flüggen Jungen im Vergleich zur Zahl der gelegten Eier) variierte zwischen 60 und 87 % und war am Südrand am höchsten. Einige Anpassungen der Lapplandmeise an rauhes nordisches Klima im Vergleich zu anderen Meisen werden diskutiert.相似文献
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Estefânia Mara do Nascimento Martins Bernardo Sgarbi Reis Maria Aparecida de Resende Antero Silva Ribeiro de Andrade Alfredo Miranda Goes 《Mycopathologia》2009,168(2):51-58
Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, the most prevalent mycosis in Latin America. Up to the moment no vaccine has been
reported. The aim of this study was to evaluate the influence of the number of immunizations on the protection elicited by
radioattenuated yeast cells of P. brasiliensis. BALB/c mice were divided into two groups that were immunized once (Group 1) or twice (Group 2), respectively. In each group,
mice were divided into sub-groups that were challenged 30, 45, or 60 days after the second immunization. Organ colony-forming
units (CFUs) was determined 90 days post-challenge. A significant reduction in CFUs recovery was verified in both groups,
but it was higher in Group 2. Histologic alterations were observed only in Group 1. The cytokines IL-4, IL-10, and IFN-γ were
produced in mice of Group 1. In Group 2, only IFN-γ was significantly detected. IgG2a predominance relative to IgG1 was also
observed in Group 2. Altogether, our results indicated that mice immunized once developed a mixed Th1/Th2 response, which
was less efficient in the infection control, while a trend to a Th1 pattern was obtained with two immunizations, promoting
optimal elimination of P. brasiliensis yeast cells from mice tissues. 相似文献
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Recent studies have emphasized the importance of SIRT1, a mammalian homolog of Sir2 longevity factor, in the regulation of metabolism, cellular survival, and organismal lifespan. The signaling network interacting with SIRT1 continues to expand as does the number of functions known to be regulated by SIRT1. Autophagy is also an emerging field in longevity studies. Autophagocytosis is a housekeeping mechanism cleaning cells from aberrant and dysfunctional molecules and organelles. The extension of lifespan has been linked to the efficient maintenance of autophagic degradation, a process which declines during aging. Interestingly, recent observations have demonstrated that SIRT1 regulates the formation of autophagic vacuoles, either directly or indirectly through a downstream signaling network. We will examine the signaling pathways linking SIRT1 to the regulation of autophagic degradation. The interactions of SIRT1 with the FoxO and p53 signaling can also regulate both the autophagic degradation and lifespan extension emphasizing the key role of autophagy in the regulation of lifespan. 相似文献
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Summary The fairly recently established disjunctional Fennoscandian area of Chra strigosa
A. Br., which species was earlier known only from a few alpine lakes in the European Alps, is described and mapped. A survey of some of its ecological traits shows that the species requires neutral or alkaline reaction, a relatively high lime content, and probably a low chloride content of the water. The factors involved in the formation of the recent area of the species are discussed.Received for publication 30.X.1953. 相似文献