91 research outputs found

    IN VITRO STUDIES OF MAMMALIAN SOMATIC CELL VARIATION : I. DETECTION OF H-2 PHENOTYPE IN CULTURED MOUSE CELL LINES

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    The isoantigenic phenotype of the H-2 locus has been detected by isohemagglutinin absorption in a line of mouse lymphoma cells growing continuously in culture for 6 years and in two established lines of fibroblastic mouse cells growing continuously in culture for 1 year. Quantitative absorption studies suggest that the concentration of H-2 isoantigens is higher in the cultured lymphoma cells than in the other two fibroblastic cell lines

    Genotype, haplotype and copy-number variation in worldwide human populations

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    Genome-wide patterns of variation across individuals provide a powerful source of data for uncovering the history of migration, range expansion, and adaptation of the human species. However, high-resolution surveys of variation in genotype, haplotype and copy number have generally focused on a small number of population groups(1-3). Here we report the analysis of high-quality genotypes at 525,910 single-nucleotide polymorphisms ( SNPs) and 396 copy-number-variable loci in a worldwide sample of 29 populations. Analysis of SNP genotypes yields strongly supported fine-scale inferences about population structure. Increasing linkage disequilibrium is observed with increasing geographic distance from Africa, as expected under a serial founder effect for the out-of-Africa spread of human populations. New approaches for haplotype analysis produce inferences about population structure that complement results based on unphased SNPs. Despite a difference from SNPs in the frequency spectrum of the copy-number variants (CNVs) detected-including a comparatively large number of CNVs in previously unexamined populations from Oceania and the Americas-the global distribution of CNVs largely accords with population structure analyses for SNP data sets of similar size. Our results produce new inferences about inter-population variation, support the utility of CNVs in human population-genetic research, and serve as a genomic resource for human-genetic studies in diverse worldwide populations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62552/1/nature06742.pd

    Treatment of Inborn Errors of Urea Synthesis — Activation of Alternative Pathways of Waste Nitrogen Synthesis and Excretion

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    Abstract Children with inborn errors of urea synthesis accumulate ammonium and other nitrogenous precursors of urea, leading to episodic coma and a high mortality rate. We used alternative pathways for the excretion of waste nitrogen as substitutes for the defective ureagenic pathways in 26 infants. These pathways involve synthesis and excretion of hippurate after sodium benzoate administration, and of citrulline and argininosuccinate after arginine supplementation. The children were treated for seven to 62 months; 22 survived. The mean plasma level of ammonium (±S.E.) was 36±2 μmol per liter, and that of benzoate was 1.5±1.0 mg per deciliter. Alternative pathways accounted for between 28 and 59 per cent of the total effective excretion of waste nitrogen. Nineteen infants had normal height, weight, and head circumference, and 13 had normal intellectual development. Activation of alternative pathways of waste nitrogen excretion can prolong survival and improve clinical outcome in children with inborn errors of urea synthesis. (N Engl J Med. 1982; 306:1387–92.

    Genetic Variation in the HSD17B1 Gene and Risk of Prostate Cancer

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    Steroid hormones are believed to play an important role in prostate carcinogenesis, but epidemiological evidence linking prostate cancer and steroid hormone genes has been inconclusive, in part due to small sample sizes or incomplete characterization of genetic variation at the locus of interest. Here we report on the results of a comprehensive study of the association between HSD17B1 and prostate cancer by the Breast and Prostate Cancer Cohort Consortium, a large collaborative study. HSD17B1 encodes 17β-hydroxysteroid dehydrogenase 1, an enzyme that converts dihydroepiandrosterone to the testosterone precursor Δ5-androsterone-3β,17β-diol and converts estrone to estradiol. The Breast and Prostate Cancer Cohort Consortium researchers systematically characterized variation in HSD17B1 by targeted resequencing and dense genotyping; selected haplotype-tagging single nucleotide polymorphisms (htSNPs) that efficiently predict common variants in U.S. and European whites, Latinos, Japanese Americans, and Native Hawaiians; and genotyped these htSNPs in 8,290 prostate cancer cases and 9,367 study-, age-, and ethnicity-matched controls. We found no evidence that HSD17B1 htSNPs (including the nonsynonymous coding SNP S312G) or htSNP haplotypes were associated with risk of prostate cancer or tumor stage in the pooled multiethnic sample or in U.S. and European whites. Analyses stratified by age, body mass index, and family history of disease found no subgroup-specific associations between these HSD17B1 htSNPs and prostate cancer. We found significant evidence of heterogeneity in associations between HSD17B1 haplotypes and prostate cancer across ethnicity: one haplotype had a significant (p < 0.002) inverse association with risk of prostate cancer in Latinos and Japanese Americans but showed no evidence of association in African Americans, Native Hawaiians, or whites. However, the smaller numbers of Latinos and Japanese Americans in this study makes these subgroup analyses less reliable. These results suggest that the germline variants in HSD17B1 characterized by these htSNPs do not substantially influence the risk of prostate cancer in U.S. and European whites

    A randomised controlled trial of the efficacy of the ABCD Parenting Young Adolescents Program: rationale and methodology

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    Background: The transition to adolescence is a time of increased vulnerability for risk taking and poor health, social and academic outcomes. Parents have an important role in protecting their children from these potential harms. While the effectiveness of parenting programs in reducing problem behavior has been demonstrated, it is not known if parenting programs that target families prior to the onset of significant behavioral difficulties in early adolescence (9-14 years) improve the wellbeing of adolescents and their parents. This paper describes the rationale and methodology of a randomised controlled trial testing the efficacy of a parenting program for the promotion of factors known to be associated with positive adolescent outcomes, such as positive parenting practices, parent-adolescent relationships and adolescent behavior.Methods/Design: One hundred and eighty parents were randomly allocated to an intervention or wait list control group. Parents in the intervention group participated in the ABCD Parenting Young Adolescents Program, a 6-session behavioral family intervention program which also incorporates acceptance-based strategies. Participants in the Wait List control group did not receive the intervention during a six month waiting period. The study was designed to comply with recommendations of the CONSORT statement. The primary outcome measures were reduction in parent-adolescent conflict and improvements in parent-adolescent relationships. Secondary outcomes included improvements in parent psychosocial wellbeing, parenting self-efficacy and perceived effectiveness, parent-adolescent communication and adolescent behavior.Conclusions: Despite the effectiveness of parenting programs in reducing child behavioral difficulties, very few parenting programs for preventing problems in adolescents have been described in the peer reviewed literature. This study will provide data which can be used to examine the efficacy of a universal parenting interventions for the promotion of protective factors associated with adolescent wellbeing and will add to the literature regarding the relationships between parent, parenting and adolescent factors

    The Fecal Viral Flora of Wild Rodents

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    The frequent interactions of rodents with humans make them a common source of zoonotic infections. To obtain an initial unbiased measure of the viral diversity in the enteric tract of wild rodents we sequenced partially purified, randomly amplified viral RNA and DNA in the feces of 105 wild rodents (mouse, vole, and rat) collected in California and Virginia. We identified in decreasing frequency sequences related to the mammalian viruses families Circoviridae, Picobirnaviridae, Picornaviridae, Astroviridae, Parvoviridae, Papillomaviridae, Adenoviridae, and Coronaviridae. Seventeen small circular DNA genomes containing one or two replicase genes distantly related to the Circoviridae representing several potentially new viral families were characterized. In the Picornaviridae family two new candidate genera as well as a close genetic relative of the human pathogen Aichi virus were characterized. Fragments of the first mouse sapelovirus and picobirnaviruses were identified and the first murine astrovirus genome was characterized. A mouse papillomavirus genome and fragments of a novel adenovirus and adenovirus-associated virus were also sequenced. The next largest fraction of the rodent fecal virome was related to insect viruses of the Densoviridae, Iridoviridae, Polydnaviridae, Dicistroviriade, Bromoviridae, and Virgaviridae families followed by plant virus-related sequences in the Nanoviridae, Geminiviridae, Phycodnaviridae, Secoviridae, Partitiviridae, Tymoviridae, Alphaflexiviridae, and Tombusviridae families reflecting the largely insect and plant rodent diet. Phylogenetic analyses of full and partial viral genomes therefore revealed many previously unreported viral species, genera, and families. The close genetic similarities noted between some rodent and human viruses might reflect past zoonoses. This study increases our understanding of the viral diversity in wild rodents and highlights the large number of still uncharacterized viruses in mammals

    AI is a viable alternative to high throughput screening: a 318-target study

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    : High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
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