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991.
Petteri Nieminen Heikki Hyvrinen Reijo Kkel Juha Asikainen 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2000,127(4)
Female minks (Mustela vison) fed diets based on freshwater, marine or mixed fish were exposed to 1 mg of polychlorinated biphenyls (PCBs) a day for 21 weeks. The plasma leptin and thyroxine concentrations and the glucose-6-phosphatase and glycogen phophorylase activities in the liver were measured at the end of the experiment. The plasma thyroxine concentrations were significantly higher in the group exposed to PCBs. The mean plasma leptin concentration and glucose-6-phosphatase activity was the highest in the group that had the lowest body-mass index (BMI). The glycogen phophorylase activity was the highest in the freshwater fish-control group. The results suggest that the amount of fat in the body of the female minks is not the only determinant of the plasma leptin levels, but the leptin levels seem to rise with a lowered BMI unlike in rodents or humans. The positive correlation between the leptin levels and the glucose-6-phosphatase activity suggests increased gluconeogenesis with high leptin levels. Subchronic exposure to PCBs seems to have no effect on the plasma leptin levels or the glucose-6-phophatase activities, but it elevates significantly the plasma thyroxine levels with a mechanism that remains unknown. 相似文献
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994.
Luděk Vyšín Kateřina Pachnerová Brabcová Václav Štěpán Patrick Moretto-Capelle Beatrix Bugler Gaelle Legube Pierre Cafarelli Romain Casta Jean Philippe Champeaux Martine Sence Martin Vlk Richard Wagner Jan Štursa Václav Zach Sebastien Incerti Libor Juha Marie Davídková 《Radiation and environmental biophysics》2015,54(3):343-352
995.
Juho-Antti Junno Sirpa Niinimäki Markku Niskanen Milton Nunez Juha Tuukkanen 《HOMO》2011,62(6):459-465
This study examines the cross sectional shape and biomechanical properties of the radial bone shaft at mid-radial tuberosity (RT) musculoskeletal marker (MSM). This information will provide insight into factors affecting bone modelling at muscle insertions. Radial shaft cross-sectional properties at radial tuberosity area (RTA) have not been previously studied. The material consists of 54 male skeletons derived from autopsies performed during the 1920s and 1930s and housed at the Central Natural History Museum, University of Helsinki. The age, sex and occupation of these individuals are known. We applied a pQCT (peripheral quantitative computed tomography) scan on the mid-site of the radial tuberosity to investigate the cross-sectional shape, the bone mineral density (BMD) and biomechanical properties. Our results indicate that bone modelling does not produce increased wall thickness or BMD at the RT site. Additionally we noticed that aging and physical activity affect the biomechanics of the RT and that the bone distribution at mid-RT is adapted to accommodate the biceps brachii muscle pull. We also found a clear association between RTA and biomechanical properties of mid-RT cross section. 相似文献
996.
Quantitative trait and allozyme divergence in the Greenfinch (Carduelis chloris, Aves: Fringillidae)
Juha Merila 《Biological journal of the Linnean Society. Linnean Society of London》1997,61(2):243-266
Quantitative trait divergence and variability among 12 greenfinch populations across continental Europe was examined and compared to divergence in neutral genetic markers (allozymes). The added among locality variance component for 16 skeletal traits was large (mean 28%, range 4–48%) equalling a divergence of up to three SD units. The divergence in quantitative traits (Qst = 0.04-0.48) greatly exceeded that in alloymes (FST = 0.01-0.07), indicating the differentiation in quantitative traits to be larger than expected by mutation and drift alone. This conclusion was consistent also with results from the multivariate approach of Rogers & Harpending. However, genetic and morphometric distances between populations were positively correlated, even when controlling for the geographic distance separating pairs of populations. In concordance with Bergmann's rule, most traits were strongly and positively correlated with latitude, indicating latitudinally ordered genetic or/and environmental effects. However, the correlation between lower mandible width and latitude was strongly negative, demonstrating an inverse relationship between beak size and body size across the populations. These results are interpreted to reflect the re-colonization of history of northern Europe (genetic and geographic distances correlated) which has been paralleled by selection acting on quantitative traits (QST >FST )- In particular, the counter-gradient variation in beak width, a functionally important trait, is suggestive of an adaptive basis for quantitative trait divergence. 相似文献
997.
Mikko Ylilauri Elina Mattila Elisa M. Nurminen Jarmo Käpylä Sanna P. Niinivehmas Juha A. Määttä Ulla Pentikäinen Johanna Ivaska Olli T. Pentikäinen 《Biochimica et Biophysica Acta - Proteins and Proteomics》2013,1834(10):1988-1997
T-cell protein tyrosine phosphatase (TCPTP) is a ubiquitously expressed non-receptor protein tyrosine phosphatase. It is involved in the negative regulation of many cellular signaling pathways. Thus, activation of TCPTP could have important therapeutic applications in diseases such as cancer and inflammation. We have previously shown that the α-cytoplasmic tail of integrin α1β1 directly binds and activates TCPTP. In addition, we have identified in a large-scale high-throughput screen six small molecules that activate TCPTP. These small molecule activators include mitoxantrone and spermidine. In this study, we have investigated the molecular mechanism behind agonist-induced TCPTP activation. By combining several molecular modeling and biochemical techniques, we demonstrate that α1-peptide and mitoxantrone activate TCPTP via direct binding to the catalytic domain, whereas spermidine does not interact with the catalytic domain of TCPTP in vitro. Furthermore, we have identified a hydrophobic groove surrounded by negatively charged residues on the surface of TCPTP as a putative binding site for the α1-peptide and mitoxantrone. Importantly, these data have allowed us to identify a new molecule that binds to TCPTP, but interestingly cannot activate its phosphatase activity. Accordingly, we describe here mechanism of TCPTP activation by mitoxantrone, the cytoplasmic tail of α1-integrin, and a mitoxantrone-like molecule at the atomic level. These data provide invaluable insight into the development of novel TCPTP activators, and may facilitate the rational discovery of small-molecule cancer therapeutics. 相似文献
998.
Ilkka Y Järvelä Juha S Tapanainen Hannu Martikainen 《Reproductive biology and endocrinology : RB&E》2010,8(1):18
Background
In natural cycles, women conceive when intercourse takes place during a six-day period ending on the day of ovulation. The current practice in intrauterine insemination (IUI) cycles is to perform the IUI 24-36 hours after the hCG administration, when the ovulation is already imminent. In this study hCG was administered after the IUI, which more closely resembles the fertilisation process in natural cycles. 相似文献999.
1000.
Juha Oksa Hannu Kaikkonen Pasi Sorvisto Marko Vaappo Vesa Martikkala Hannu Rintamki 《Journal of thermal biology》2004,29(7-8):815-818
Sixteen subjects were exposed to varying climatic conditions (20 to −20 °C) while exercising with different intensities from light to maximal. The results indicate that maximal cardiorespiratory capacity is lowered and submaximal strain is increased when ambient working temperature decreases. This means that the individual strain caused by a given submaximal workload may be significantly higher in cold as compared to thermoneutral environment due to cooling, use of additional clothing or their combination. 相似文献