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81.
82.
Genome-wide association studies (GWASs) have identified several, mainly co-dominantly acting, single-nucleotide polymorphisms (SNPs) associated with Hodgkin lymphoma (HL). We searched for recessively acting disease loci by performing an analysis of runs of homozygosity (ROH) based on windows of homozygous SNP-blocks and by calculating genomic inbreeding coefficients on a SNP-wise basis. We used data from a previous GWAS with 906 cases and 1217 controls from a population with a long history of no matings between relatives. Ten recurrent ROHs were identified among 25 055 ROHs across all individuals but their association with HL was not genome-wide significant. All recurrent ROHs showed significant evidence for natural selection. As a novel finding genomic inbreeding among cases was significantly higher than among controls (P = 2.11*10−14) even after correcting for covariates. Higher inbreeding among the cases was mainly based on a group of individuals with a higher average length of ROHs per person. This result suggests a correlation of higher levels of inbreeding with higher cancer incidence and might reflect the existence of recessive alleles causing HL. Genomic inbreeding may result in a higher expression of deleterious recessive genes within a population.  相似文献   
83.
MicroRNAs (miRNAs) regulate specific immune mechanisms, but their genome-wide regulation of T lymphocyte activation is largely unknown. We performed a multidimensional functional genomics analysis to integrate genome-wide differential mRNA, miRNA, and protein expression as a function of human T lymphocyte activation and time. We surveyed expression of 420 human miRNAs in parallel with genome-wide mRNA expression. We identified a unique signature of 71 differentially expressed miRNAs, 57 of which were previously not known as regulators of immune activation. The majority of miRNAs are upregulated, mRNA expression of these target genes is downregulated, and this is a function of binding multiple miRNAs (combinatorial targeting). Our data reveal that consideration of this complex signature, rather than single miRNAs, is necessary to construct a full picture of miRNA-mediated regulation. Molecular network mapping of miRNA targets revealed the regulation of activation-induced immune signaling. In contrast, pathways populated by genes that are not miRNA targets are enriched for metabolism and biosynthesis. Finally, we specifically validated miR-155 (known) and miR-221 (novel in T lymphocytes) using locked nucleic acid inhibitors. Inhibition of these two highly upregulated miRNAs in CD4(+) T cells was shown to increase proliferation by removing suppression of four target genes linked to proliferation and survival. Thus, multiple lines of evidence link top functional networks directly to T lymphocyte immunity, underlining the value of mapping global gene, protein, and miRNA expression.  相似文献   
84.
Preterm birth is the major cause of neonatal death and serious morbidity. Most preterm births are due to spontaneous onset of labor without a known cause or effective prevention. Both maternal and fetal genomes influence the predisposition to spontaneous preterm birth (SPTB), but the susceptibility loci remain to be defined. We utilized a combination of unique population structures, family-based linkage analysis, and subsequent case-control association to identify a susceptibility haplotype for SPTB. Clinically well-characterized SPTB families from northern Finland, a subisolate founded by a relatively small founder population that has subsequently experienced a number of bottlenecks, were selected for the initial discovery sample. Genome-wide linkage analysis using a high-density single-nucleotide polymorphism (SNP) array in seven large northern Finnish non-consanginous families identified a locus on 15q26.3 (HLOD 4.68). This region contains the IGF1R gene, which encodes the type 1 insulin-like growth factor receptor IGF-1R. Haplotype segregation analysis revealed that a 55 kb 12-SNP core segment within the IGF1R gene was shared identical-by-state (IBS) in five families. A follow-up case-control study in an independent sample representing the more general Finnish population showed an association of a 6-SNP IGF1R haplotype with SPTB in the fetuses, providing further evidence for IGF1R as a SPTB predisposition gene (frequency in cases versus controls 0.11 versus 0.05, P = 0.001, odds ratio 2.3). This study demonstrates the identification of a predisposing, low-frequency haplotype in a multifactorial trait using a well-characterized population and a combination of family and case-control designs. Our findings support the identification of the novel susceptibility gene IGF1R for predisposition by the fetal genome to being born preterm.  相似文献   
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Corynebacterium (Eubacterium) suis strains from boars and sows haemagglutinated erythrocytes of different animal species (calf, guinea pig, poultry, pig, and human). The haemaigglutination was man nose resistant (MR) and was neither inhibited by L-fucose nor D-galactose. The hydrophobicity measured by salt aggregation test (0.1–0.9 mol/1 (NH4)2SO4) and the hydrophobic interaction chromatography test (90 % retention in octyl sepharose) together with the haemagglutinating activity, indicated the presence of fimbriae on the bacteria. The haemagglutinating and hydrophobic properties were heat-sensitive (60°C for 10 min) suggestive of the presence of a protein structure. Two types of fimbria-tion were demonstrated by electron microscopy. Fetuin and glyco^ protein inhibited the haemagglutination, whereas porcine mucin was without any effect. These results indicate that branched glycoproteins might be important receptors for these fimbriae. The pathogenic aspects of C. suis are discussed, based on recent acquired knowledge of the effect of other pyelonephritogenic bacteria.  相似文献   
87.
Hepatic arterial infusion chemotherapy (HAIC) for unresectable hepatic neoplasms has been associated with gastric ulcers and epithelial atypia that may be misinterpreted as carcinoma. Gastric brushings were reviewed from six patients who developed gastric ulcers with histologically proven atypia following HAIC. Marked cytologic atypia, reminiscent of a pronounced radiation effect, was present in gastric epithelial cells in five patients. The atypical cells occurred singly or in small sheets. They were markedly enlarged but a low nuclear-cytoplasmic ratio was preserved. The abundant cytoplasm was vacuolated or foamy. Binucleation and multinucleation were common, and massive nucleoli were characteristic. The brushings also contained the reparative, inflammatory and necrotic changes associated with usual benign gastric ulcers. The bizarre atypia associated with HAIC can be a source of misdiagnosis of cancer in cytologic as well as in histologic specimens.  相似文献   
88.
89.
Lipid composition of the benthic, stenothermal amphipod Monoporeia affinis collected from constantly cold deep-water (> 80 m) regions of the northern Baltic Sea was analysed in detail to study phospholipid characteristics, its relation to thermal adaptation as well as potential effects of food quality and seasonal variability. Similar measurements were performed on the littoral, eurythermic amphipod Gammarus spp. Fatty acid (FA) composition of storage lipids of Pontoporeia femorata, a sibling species of M. affinis, was also studied. Interannual and interspecies variability in selected FA was observed both in triacylglycerols (TAG) and phospholipids (PL). Differences in monounsaturated vs. polyunsaturated (MUFA/PUFA) FA combinations of phosphatidyl ethanolamine (PE) diacyl and alkylacyl subgroups were also observed. Seasonal variability in M. affinis was considerably lesser compared to Gammarus spp. A literature synopsis shows that in diacyl PE the share of the FA combination MUFA/PUFA increases with lowering body temperature (40-55% in cold-adapted organisms vs. 5-15% in warm adapted ones), signifying that this characteristic is probably in key position concerning regulation of membrane fluidity in temperature adaptation. According to this feature M. affinis belongs to the group of cold-adapted stenothermic species (Group 1) while eurythermic Gammarus spp. settles in the Group 2 (cold-acclimatized) or 3 (warm-acclimatized/tropical) depending on the status of temperature adaptation. Omnivory and/or periodical food item switching is an important strategy in benthic organisms in high-latitude areas characterised by recurring long poor-nutritional periods. Since many benthic species utilise a time-averaged, integrated food source from phytal and animal matter from various sources the FA composition of TAG of the amphipod species measured here do not exclusively point towards any specific feeding mode or food source. In general, using selected FA as food source markers to assess the diet of field collected more-or-less omnivoric species cannot be considered as an optimal approach. The current study gives more insight to the biochemistry of biological membranes of aquatic crustaceans that is essential in estimation of the capacity of the thermal adaptation/acclimatization of organisms as well as the potential effects of food quality on storage lipids.  相似文献   
90.
Overabundance of woody plants in semiarid ecosystems can degrade understory herbaceous vegetation and often requires shrub reduction and seeding to recover ecosystem services. We used meta‐analysis techniques to assess the effects of fire and mechanical shrub reduction over two post‐treatment timeframes (1–4 and 5–10 years) on changes in cover and frequency of 15 seeded species at 63 restoration sites with high potential for recovery. Compared to mechanical treatments, fire resulted in greater increases in seeded species. Native shrubs did not increase, and forbs generally declined over time; however, large increases in perennial grasses were observed, suggesting that seeding efforts contributed to enhanced understory herbaceous conditions. We found greater increases in a few non‐native species than native species across all treatments, suggesting the possibility that interference among seeded species may have influenced results of this regional assessment. Differences among treatments and species were likely driven by seedbed conditions, which should be carefully considered in restoration planning. Site characteristics also dictated seeded species responses: while forbs showed greater increases in cover over the long term at higher elevation sites considered to be more resilient to disturbance, surprisingly, shrubs and grasses had greater increases in cover and frequency at lower elevation sites where resilience is typically much lower. Further research is needed to understand the causes of forb mortality over time, and to decipher how greater increases of non‐native relative to native seeded species will influence species diversity and successional trajectories of restoration sites.  相似文献   
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