1,549 research outputs found

    Direct Assessment of Cumulative Aryl Hydrocarbon Receptor Agonist Activity in Sera from Experimentally Exposed Mice and Environmentally Exposed Humans

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    Background: Aryl hydrocarbon receptor (AhR) ligands adversely affect many biological processes. However, assessment of the significance of human exposures is hampered by an incomplete understanding of how complex mixtures affect AhR activation/inactivation. Objectives: These studies used biological readouts to provide a broader context for estimating human risk than that obtained with serum extraction and gas chromatography/mass spectroscopy (GC/MS)-based assays alone. Methods: AhR agonist activity was quantified in sera from dioxin-treated mice, commercial human sources, and polychlorinated biphenyl (PCB)–exposed Faroe Islanders using an AhR-driven reporter cell line. To validate relationships between serum AhR agonist levels and biological outcomes, AhR agonist activity in mouse sera correlated with toxic end points. AhR agonist activity in unmanipulated (“neat”) human sera was compared with these biologically relevant doses and with GC/MS-assayed PCB levels. Results: Mouse serum AhR agonist activity correlated with injected dioxin dose, thymic atrophy, and heptomegaly, validating the use of neat serum to assess AhR agonist activity. AhR agonist activity in sera from Faroe Islanders varied widely, was associated with the frequency of recent pilot whale dinners, but did not correlate with levels of PCBs quantified by GC/MS. Surprisingly, significant “baseline” AhR activity was found in commercial human sera. Conclusions: An AhR reporter assay revealed cumulative levels of AhR activation potential in neat serum, whereas extraction may preclude detection of important non-dioxin-like biological activity. Significant levels of AhR agonist activity in commercial sera and in Faroe Islander sera, compared with that from experimentally exposed mice, suggest human exposures that are biologically relevant in both populations

    Rapid ex vivo reverse genetics identifies the essential determinants of prion protein toxicity

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    The cellular prion protein PrPC^{C} mediates the neurotoxicity of prions and other protein aggregates through poorly understood mechanisms. Antibody-derived ligands against the globular domain of PrPC^{C} (GDL) can also initiate neurotoxicity by inducing an intramolecular R208_{208} -H140_{140} hydrogen bond ("H-latch") between the α2-α3 and β2-α2 loops of PrPC^{C} . Importantly, GDL that suppresses the H-latch prolong the life of prion-infected mice, suggesting that GDL toxicity and prion infections exploit convergent pathways. To define the structural underpinnings of these phenomena, we transduced 19 individual PrPC^{C} variants to PrPC^{C} -deficient cerebellar organotypic cultured slices using adenovirus-associated viral vectors (AAV). We report that GDL toxicity requires a single N-proximal cationic residue (K27_{27} or R27_{27} ) within PrPC^{C} . Alanine substitution of K27_{27} also prevented the toxicity of PrPC^{C} mutants that induce Shmerling syndrome, a neurodegenerative disease that is suppressed by co-expression of wild-type PrPC^{C} . K27_{27} may represent an actionable target for compounds aimed at preventing prion-related neurodegeneration

    GM-CSF DNA: An adjuvant for higher avidity IgG, rectal IgA, and increased protection against the acute phase of a SHIV-89.6P challenge by a DNA/MVA immunodeficiency virus vaccine

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    AbstractSingle intradermal or intramuscular inoculations of GM-CSF DNA with the DNA prime for a simian–human immunodeficiency virus (SHIV)-89.6 vaccine, which consists of DNA priming followed by modified vaccinia Ankara (MVA) boosting, increased protection of both the blood and intestines against the acute phase of an intrarectal SHIV-89.6P challenge. GM-CSF appeared to contribute to protection by enhancing two antibody responses: the avidity maturation of anti-Env IgG in blood (p=<0.01) and the presence of long lasting anti-viral IgA in rectal secretions (p<0.01). The avidity of anti-Env IgG showed strong correlations with protection both pre and post challenge. Animals with the highest avidity anti-Env Ab had 1000-fold reductions in peak viremia over those with the lowest avidity anti-Env Ab. The enhanced IgA response was associated with the best protection, but did not achieve significance

    ABA Criminal Justice Section Task Force on College Due Process Rights and Victim Protections: Recommendations for Colleges and Universities in Resolving Allegations of Campus Sexual Misconduct

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    The Executive Committee of the ABA Criminal Justice Section commissioned the Task Force on College Due Process Rights and Victim Protections in November 2016. Immediately after, extensive efforts were made to find members that represented all interested parties: victims, the accused, universities, other stakeholders, and national experts. The Task Force was fully constituted in the winter of 2017, and it ended up including two voting members who were originally liaisons from the ABA Commission on Domestic and Sexual Violence and the ABA Section of Civil Rights and Social Justice. This elevation was made in recognition of their significant contributions

    Establishing a Primary Care Alliance for Conducting Cancer Prevention Clinical Research at Community Sites

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    In September 2020, the National Cancer Institute convened the first PARTNRS Workshop as an initiative to forge partnerships between oncologists, primary care professionals, and non-oncology specialists for promoting patient accrual into cancer prevention trials. This effort is aimed at bringing about more effective accrual methods to generate decisive outcomes in cancer prevention research. The workshop convened to inspire solutions to challenges encountered during the development and implementation of cancer prevention trials. Ultimately, strategies suggested for protocol development might enhance integration of these trials into community settings where a diversity of patients might be accrued. Research Bases (cancer research organizations that develop protocols) could encourage more involvement of primary care professionals, relevant prevention specialists, and patient representatives with protocol development beginning at the concept level to improve adoptability of the trials within community facilities, and consider various incentives to primary care professionals (i.e., remuneration). Principal investigators serving as liaisons for the NCORP affiliates and sub-affiliates, might produce and maintain Prevention Research Champions lists of PCPs and non-oncology specialists relevant in prevention research who can attract health professionals to consider incorporating prevention research into their practices. Finally, patient advocates and community health providers might convince patients of the benefits of trial-participation and encourage shared-decision making

    Partial efficacy of a VSV-SIV/MVA-SIV vaccine regimen against oral SIV challenge in infant macaques

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    Despite antiretroviral medications, the rate of pediatric HIV-1 infections through breast-milk transmission has been staggering in developing countries. Therefore, the development of a vaccine to protect vulnerable infant populations should be actively pursued. We previously demonstrated that oral immunization of newborn macaques with vesicular stomatitis virus expressing simian immunodeficiency virus genes (VSV-SIV) followed 2 weeks later by an intramuscular boost with modified vaccinia ankara virus expressing SIV (MVA-SIV) successfully induced SIV-specific T and B cell responses in multiple lymphoid tissues, including the tonsil and intestine [13]. In the current study, we tested the oral VSV-SIV prime/systemic MVA-SIV boost vaccine for efficacy against multiple oral SIVmac251 challenges starting two weeks after the booster vaccination. The vaccine did not prevent SIV infection. However, in vaccinated infants, the level of SIV-specific plasma IgA (but not IgG) at the time of challenge was inversely correlated with peak viremia. In addition, the levels of SIV-specific IgA in saliva and plasma were inversely correlated with viral load at euthanasia. Animals with tonsils that contained higher frequencies of SIV-specific TNF-α- or IFN-γ-producing CD8+ T cells and central memory T cells at euthanasia also had lower viremia. Interestingly, a marked depletion of CD25+ FoxP3+ CD4+ T cells was observed in the tonsils as well as the intestine of these animals, implying that T regulatory cells may be a major target of SIV infection in infant macaques. Overall, the data suggest that, in infant macaques orally infected with SIV, the co-induction of local antiviral cytotoxic T cells and T regulatory cells that promote the development of IgA responses may result in better control of viral replication. Thus, future vaccination efforts should be directed towards induction of IgA and mucosal T cell responses to prevent or reduce virus replication in infants

    BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

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    Background: The K3326X variant in BRCA2 (BRCA2*c.9976A&gt;T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

    SIVmac239 MVA vaccine with and without a DNA prime, similar prevention of infection by a repeated dose SIVsmE660 challenge despite different immune responses

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    Vaccine regimens using different agents for priming and boosting have become popular for enhancing T cell and Ab responses elicited by candidate HIV/AIDS vaccines. Here we use a simian model to evaluate immunogenicity and protective efficacy of a recombinant modified vaccinia Ankara (MVA) vaccine in the presence and absence of a recombinant DNA prime. The simian vaccines and regimens represent prototypes for candidate HIV vaccines currently undergoing clinical testing

    Genome-wide association analysis of susceptibility and clinical phenotype in multiple sclerosis

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    Multiple sclerosis (MS), a chronic disorder of the central nervous system and common cause of neurological disability in young adults, is characterized by moderate but complex risk heritability. Here we report the results of a genome-wide association study performed in a 1000 prospective case series of well-characterized individuals with MS and group-matched controls using the Sentrix® HumanHap550 BeadChip platform from Illumina. After stringent quality control data filtering, we compared allele frequencies for 551 642 SNPs in 978 cases and 883 controls and assessed genotypic influences on susceptibility, age of onset, disease severity, as well as brain lesion load and normalized brain volume from magnetic resonance imaging exams. A multi-analytical strategy identified 242 susceptibility SNPs exceeding established thresholds of significance, including 65 within the MHC locus in chromosome 6p21.3. Independent replication confirms a role for GPC5, a heparan sulfate proteoglycan, in disease risk. Gene ontology-based analysis shows a functional dichotomy between genes involved in the susceptibility pathway and those affecting the clinical phenotyp
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