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61.
C-reactive protein (CRP) is a sensitive marker of inflammation induced by both IL-6 and IL-1. Thus, genetic variation in these genes could be associated with the variety in C-reactive protein levels, and therefore with the severity of the entire inflammatory response. Even a subtle elevation in baseline CRP levels in healthy individuals has been found to significantly increase the risk for cardiovascular diseases. Therefore, to find out the possible role of pro-inflammatory cytokines in CRP baseline regulation we conducted a study of 338 healthy blood donors whose CRP levels were determined and whose single nucleotide polymorphisms of IL1A(C/T)-889, IL1B(C/T)-511, IL1B(C/T) + 3954, IL6(G/C)-174 and ILRN (a VNTR) both genotyped and haplotyped. The data revealed an association between CRP levels and the IL1B + 3954 genotype. Also, the bilocus haplotype IL1B-511*1/IL1B + 3954*2 was more frequent in subjects with below median CRP levels (< 0.72 mg/l), and composite genotype analysis of IL1B-511/IL1B + 3954 supported this finding. Our findings suggest that in healthy people, basal CRP levels are regulated by IL1B but not by IL6 genetics.  相似文献   
62.
A single accidental event such as the fallout released from the Chernobyl reactor in 1986 can expose millions of people to non-natural environmental radiation. Ionizing radiation increases the frequency of germline mutations in experimental studies, but the genetic effects of radiation in humans remain largely undefined. To evaluate the hereditary effects of low radiation doses, we compared the minisatellite mutation rates of 155 children born to Estonian Chernobyl cleanup workers after the accident with those of their siblings born prior to it. All together, 94 de novo paternal minisatellite mutations were found at eight tested loci (52 and 42 mutants among children born after and before the accident, respectively). The minisatellite mutation rate was nonsignificantly increased among children born after the accident (0.042 compared to 0.036, OR 1.33, 95% CI 0.80-2.20). Furthermore, there was some indication of an increased mutation rate among offspring born after the accident to workers who had received doses of 20 cSv or above compared with their siblings born before the accident (OR 3.0, 95% CI 0.97-9.30). The mutation rate was not associated with the father's age (OR 1.04, 95% CI 0.94-1.15) or the sex of the child (OR 0.95, 95% CI 0.50-1.79). Our results are consistent with both no effect of radiation on minisatellite mutations and a slight increase at dose levels exceeding 20 cSv.  相似文献   
63.
Species living in highly fragmented landscapes typically occur as metapopulations with frequent turnover of local populations. The turnover rate depends on population sizes and connectivities, but it may also depend on the phenotypic and genotypic composition of populations. The Glanville fritillary butterfly (Melitaea cinxia) in Finland uses two host plant species, which show variation in their relative abundances at two spatial scales: locally among individual habitat patches and regionally among networks of patches. Female butterflies in turn exhibit spatial variation in genetically determined host plant preference within and among patch networks. Emigration, immigration and establishment of new populations have all been shown to be strongly influenced by the match between the host plant composition of otherwise suitable habitat patches and the host plant preference of migrating butterflies. The evolutionary consequences of such biased migration and colonization with respect to butterfly phenotypes might differ depending on spatial configuration and plant species composition of the patches in heterogeneous patch networks. Using a spatially realistic individual-based model we show that the model-predicted evolution of host plant preference due to biased migration explains a significant amount of the observed variation in host plant use among metapopulations living in dissimilar networks. This example illustrates how the ecological extinction-colonization dynamics may be linked with the evolutionary dynamics of life history traits in metapopulations.  相似文献   
64.
Surgical transfer of in vivo produced conventionally frozen-thawed embryos of farmed European polecat (Mustela putorius) was investigated as a part of an ex-situ preservation program which has the long-term aim of developing a genome resource bank for the endangered European mink (Mustela lutreola). Eighteen oestrous yearling European polecat donors were mated once daily on two consecutive days using 13 fertile males. The donors were surgically flushed for embryos 8-9 days after the first mating. The embryo recovery rate was 60% (116 embryos/193 corpora lutea). The embryos were cryopreserved with 1.5 M ethylene glycol in a programmable freezer using a conventional slow freezing protocol. The thawed embryos were surgically transferred either after dilution with 0.5 M sucrose or directly without removal of ethylene glycol. To induce ovulation, eight recipient females were mated once daily on two consecutive days with vasectomized males starting 7 or 8 days before embryo transfer. The recipients received 7-11 embryos each and three recipients delivered a total of nine pups after a gestation length of 44-46 days. The embryo survival rate was 10% (9 pups/93 frozen embryos). This report describes the first successful cryopreservation of embryos in the Mustelidae family resulting in viable offspring. The low embryo survival rate, however, indicates that the freezing-thawing protocol needs to be improved.  相似文献   
65.
Special training methods in wrestling have been assumed to improve the stability and tolerance of the neck. The aim of this study was to measure the neck strength levels reached in an extremely physically demanding sport. A neck strength measurement system was used to measure various parameters of maximal isometric neck strength in Finnish senior wrestlers competing at the international level. The results were compared with those achieved by junior wrestlers and a control group. The means (SD) of the maximal isometric neck strength for cervical rotation were 0.4 (0.1) Nm.kg(-1) for the senior wrestlers, 0.3 (0.1) Nm.kg(-1) for the junior wrestlers, and 0.2 (0.1) Nm.kg(-1) for the nonsportsmen. The respective results for cervical flexion were 4.4 (1.4), 3.8 (0.7), and 2.3 (0.8) Nm.kg(-1); for extension, 6.0 (1.1), 5.9 (0.7), and 4.0 (0.9) Nm.kg(-1). Neck strength in flexion seems to improve more than in extension as the result of wrestling. The greatest difference was found in rotation, which in the senior wrestlers was almost 3 times that in the nonsportsmen. There was great individual variation within all groups, and the results revealed weaknesses in all directions. Maximal neck strength measurements provide information useful in planning training programs to correct possible muscle deficiency and imbalance.  相似文献   
66.
67.
The flavum strain of Tobacco mosaic virus (TMV) differs from the wild-type (wt) virus by causing strong yellow and green mosaic in the systemically infected developing leaves, yellowing in the fully expanded leaves, and distinct malformations of chloroplasts in both types of infected tissues. Analysis of the thylakoid proteins of flavum strain-infected tobacco leaves indicated that the chlorosis in mature leaves was accompanied by depletion of the entire photosystem II (PSII) core complexes and the 33-kDa protein of the oxygen evolving complex. The only change observed in the thylakoid proteins of the corresponding wt TMV-infected leaves was a slight reduction of the alpha and beta subunits of the ATP synthase complex. The coat proteins of different yellowing strains of TMV are known to effectively accumulate inside chloroplasts, but in this work, the viral movement protein also was detected in association with the thylakoid membranes of flavum strain-infected leaves. The mRNAs of different enzymes involved in the chlorophyll biosynthesis pathway were not reduced in the mature chlorotic leaves. These results suggest that the chlorosis was not caused by reduction of pigment biosynthesis, but rather, by reduction of specific proteins of the PSII core complexes and by consequent break-down of the pigments.  相似文献   
68.
69.
We have isolated the DNMT3L gene that is related to the cytosine-5-methyltransferase 3 (DNMT3) family. The gene is located on chromosome 21q22.3 between the AIRE and the KIAA0653 genes and spans approximately 16 kb of genomic sequence. The encoded protein of 387 amino acids has a cysteine-rich region containing a novel-type zinc finger domain that is conserved in DNMT3A and DNMT3B but also in ATRX, a member of the SNF2 protein family. The novel domain, called an ADD (ATRX, DNMT3, DNMT3L)-type zinc finger, contains two subparts: a C2C2 and an imperfect PHD zinc finger. Expression of the DNMT3L mRNA was not detectable by Northern blotting; however, RT-PCR amplification revealed that it is expressed at low levels in several tissues including testis, ovary, and thymus.  相似文献   
70.
The expression of alphavbeta6 fibronectin/tenascin receptor integrin is induced in malignant transformation of oral epithelium. In this study, we demonstrate the contribution of alphavbeta6 as well as other fibronectin receptor integrins in squamous cell carcinoma (SCC) cell adhesion and migration. Of 11 SCC cell lines isolated from the head and neck area, 8 (73%) expressed alphavbeta6 integrin on the cell surface. Three cell lines were chosen for further functional experiments: 1 with relatively high, 1 with moderate, and 1 with minimal surface expression of alphavbeta6 integrin. In addition to alphavbeta6, all 3 cell lines expressed alpha5beta1 and alphavbeta1 fibronectin receptor integrins. Function-blocking experiments with inhibitory anti-integrin antibodies showed that all these three integrins were functional in SCC cell spreading on fibronectin. Integrin alphavbeta6, however, was not used as a primary but as an alternative fibronectin receptor by SCC cells, as the inhibitory anti-beta6 integrin antibody alone had no effect on spreading. In migration, however, alphavbeta6, alpha5beta1, and alphavbeta1 integrins were all used in cooperation. The presence of alphavbeta1 integrin in SCC cells is a novel finding as is its contribution to SCC cell migration. When one or two of these three receptors were blocked, the cells demonstrated an adaptive ability to remain migratory using integrins that were not targeted by antibodies. Utilization of a combination of receptors of different affinities may be beneficial for SCC cell migration versatility.  相似文献   
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