408 research outputs found

    Selective suppression of autoantibody responses in NZB/NZW MICE treated with long-term cyclophosphamide

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    Autoimmune responses were assayed in 80 cyclophosphamide-treated and control NZB/NZW mice over a period of 1 year. Fluctuation between positive and negative immunofluorescent heterogeneous ANA tests and daily alterations of ANA titers were detected in young mice of both sexes. Although highdose cyclophosphamide therapy (8 mg/kg/day) failed to prevent the spontaneous appearance of ANA, titered ANA values were partially suppressed in highdose treated mice. This study permitted sequential comparisons between ANA titers and anti-DNA as useful indices of cyclophosphamide-induced suppression of autoimmune disease. ANA titers were relalively resistant to cyclophosphamide therapy. Antibodies directed specifically against DNA were suppressed in mice receiving high-dose cyclophosphamide. In treated animals, decreased anti-DNA levels were associated with protection from severe glomerulonephritis and renal vasculitis. Treatment with lowdose cyclophosphamide (1 mg/kg/day) appeared paradoxically to stimulate autoantibody production and renal disease/vasculitis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37726/1/1780180312_ftp.pd

    Distinctive serum globulin responses to parenteral treatment with 17-Î’-estradiol in female NZB/NZW mice

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    After 6 weeks of treatment with 17-Β-estradiol, two distinct groups of female NZB/NZW mice were identified. Group I females developed significant increases in serum Α 2 , Β- and Γ-globulins and had few serologic abnormalities. Serum globulins did not increase in Group II females. This blunted response correlated with a pretreatment increase in the frequency of positive tests for ANA, LE phenomena and cryoproteins in 4-week-old Group II mice.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37721/1/1780150107_ftp.pd

    Fine-mapping of the HNF1B multicancer locus identifies candidate variants that mediate endometrial cancer risk.

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    Common variants in the hepatocyte nuclear factor 1 homeobox B (HNF1B) gene are associated with the risk of Type II diabetes and multiple cancers. Evidence to date indicates that cancer risk may be mediated via genetic or epigenetic effects on HNF1B gene expression. We previously found single-nucleotide polymorphisms (SNPs) at the HNF1B locus to be associated with endometrial cancer, and now report extensive fine-mapping and in silico and laboratory analyses of this locus. Analysis of 1184 genotyped and imputed SNPs in 6608 Caucasian cases and 37 925 controls, and 895 Asian cases and 1968 controls, revealed the best signal of association for SNP rs11263763 (P = 8.4 × 10(-14), odds ratio = 0.86, 95% confidence interval = 0.82-0.89), located within HNF1B intron 1. Haplotype analysis and conditional analyses provide no evidence of further independent endometrial cancer risk variants at this locus. SNP rs11263763 genotype was associated with HNF1B mRNA expression but not with HNF1B methylation in endometrial tumor samples from The Cancer Genome Atlas. Genetic analyses prioritized rs11263763 and four other SNPs in high-to-moderate linkage disequilibrium as the most likely causal SNPs. Three of these SNPs map to the extended HNF1B promoter based on chromatin marks extending from the minimal promoter region. Reporter assays demonstrated that this extended region reduces activity in combination with the minimal HNF1B promoter, and that the minor alleles of rs11263763 or rs8064454 are associated with decreased HNF1B promoter activity. Our findings provide evidence for a single signal associated with endometrial cancer risk at the HNF1B locus, and that risk is likely mediated via altered HNF1B gene expression

    Genome-Wide Association Meta-Analysis of Single-Nucleotide Polymorphisms and Symptomatic Venous Thromboembolism during Therapy for Acute Lymphoblastic Leukemia and Lymphoma in Caucasian Children

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    Symptomatic venous thromboembolism (VTE) occurs in five percent of children treated for acute lymphoblastic leukemia (ALL), but whether a genetic predisposition exists across different ALL treatment regimens has not been well studied. Methods: We undertook a genome-wide association study (GWAS) meta-analysis for VTE in consecutively treated children in the Nordic/Baltic acute lymphoblastic leukemia 2008 (ALL2008) cohort and the Australian Evaluation of Risk of ALL Treatment-Related Side-Effects (ERASE) cohort. A total of 92 cases and 1481 controls of European ancestry were included. Results: No SNPs reached genome-wide significance (p <5 x 10(-8)) in either cohort. Among the top 34 single-nucleotide polymorphisms (SNPs) (p <1 x 10(-6)), two loci had concordant effects in both cohorts: ALOX15B (rs1804772) (MAF: 1%; p = 3.95 x 10(-7)) that influences arachidonic acid metabolism and thus platelet aggregation, and KALRN (rs570684) (MAF: 1%; p = 4.34 x 10(-7)) that has been previously associated with risk of ischemic stroke, atherosclerosis, and early-onset coronary artery disease. Conclusion: This represents the largest GWAS meta-analysis conducted to date associating SNPs to VTE in children and adolescents treated on childhood ALL protocols. Validation of these findings is needed and may then lead to patient stratification for VTE preventive interventions. As VTE hemostasis involves multiple pathways, a more powerful GWAS is needed to detect combination of variants associated with VTE.Peer reviewe

    Improving validity of informed consent for biomedical research in Zambia using a laboratory exposure intervention.

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    BACKGROUND: Complex biomedical research can lead to disquiet in communities with limited exposure to scientific discussions, leading to rumours or to high drop-out rates. We set out to test an intervention designed to address apprehensions commonly encountered in a community where literacy is uncommon, and where complex biomedical research has been conducted for over a decade. We aimed to determine if it could improve the validity of consent. METHODS: Data were collected using focus group discussions, key informant interviews and observations. We designed an intervention that exposed participants to a detailed demonstration of laboratory processes. Each group was interviewed twice in a day, before and after exposure to the intervention in order to assess changes in their views. RESULTS: Factors that motivated people to participate in invasive biomedical research included a desire to stay healthy because of the screening during the recruitment process, regular advice from doctors, free medical services, and trust in the researchers. Inhibiting factors were limited knowledge about samples taken from their bodies during endoscopic procedures, the impact of endoscopy on the function of internal organs, and concerns about the use of biomedical samples. The belief that blood can be used for Satanic practices also created insecurities about drawing of blood samples. Further inhibiting factors included a fear of being labelled as HIV positive if known to consult heath workers repeatedly, and gender inequality. Concerns about the use and storage of blood and tissue samples were overcome by a laboratory exposure intervention. CONCLUSION: Selecting a group of members from target community and engaging them in a laboratory exposure intervention could be a useful tool for enhancing specific aspects of consent for biomedical research. Further work is needed to determine the extent to which improved understanding permeates beyond the immediate group participating in the intervention
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