247 research outputs found

    A dimeric form of the HIV-1 antibody 2G12 elicits potent antibody-dependent cellular cytotoxicity

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    Objective: Increasing data support a role for antibody-dependent cellular cytotoxicity (ADCC) in controlling HIV-1 infection. We recently isolated a naturally occurring dimeric form of the anti-HIV-1 antibody 2G12 and found it to be significantly more potent than 2G12 monomer in neutralizing primary virus strains. However, given the unusual structure of dimeric 2G12 with two Fc regions, it was not clear whether 2G12 dimer could bind to the CD16 Fc receptor on ADCC effector cells or trigger ADCC. Here we compared the in-vitro ADCC activities of 2G12 monomer and dimer and investigated the effects of including ADCC-enhancing mutations in both forms of 2G12. Methods: An in-vitro ADCC assay using target cells stably expressing gp160 was developed to evaluate the activities of 2G12 monomer and dimer with and without ADCC-enhancing mutations that increase the CD16-binding affinity of the 2G12 Fc region. Results: Both 2G12 monomer and 2G12 dimer elicited ADCC, although the dimer showed increased potency [lower half-maximal concentration (EC50)] in triggering ADCC, thus confirming its ability to bind CD16 and trigger ADCC. The ADCC-enhancing mutations improved the ADCC activity of 2G12 monomer more than 2G12 dimer such that their EC50 values were nearly equal. However, no increase in nonspecific ADCC activity was observed using 2G12 IgGs with these mutations. Conclusion: Given the likelihood that ADCC plays a role in protecting against initial infection and/or controlling chronic infection, these data suggest 2G12 dimers and/or addition of ADCC-enhancing mutations could augment the prophylactic and/or therapeutic potential of 2G12

    General Solution of the non-abelian Gauss law and non-abelian analogs of the Hodge decomposition

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    General solution of the non-abelian Gauss law in terms of covariant curls and gradients is presented. Also two non-abelian analogs of the Hodge decomposition in three dimensions are addressed. i) Decomposition of an isotriplet vector field Via(x)V_{i}^{a}(x) as sum of covariant curl and gradient with respect to an arbitrary background Yang-Mills potential is obtained. ii) A decomposition of the form Via=Bia(C)+Di(C)ϕaV_{i}^{a}=B_{i}^{a}(C)+D_{i}(C) \phi^{a} which involves non-abelian magnetic field of a new Yang-Mills potential C is also presented. These results are relevant for duality transformation for non-abelian gauge fields.Comment: 6 pages, no figures, revte

    Global mental health and climate change: A geo-psychiatry perspectiv

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    Climate changes affect planet ecosystems, living beings, humans, including their lives, rights, economy, housing, migration, and both physical and mental health. Geo-psychiatry is a new discipline within the field of psychiatry studying the interface between various geo-political factors including geographical, political, economic, commercial and cultural determinants which affect society and psychiatry: it provides a holistic overview on global issues such as climate changes, poverty, public health and accessibility to health care. It identifies geopolitical factors and their effects at the international and national levels, as well as considers the politics of climate changes and poverty within this context. This paper then introduces the Compassion, Assertive Action, Pragmatism, and Evidence Vulnerability Index (CAPE-VI) as a global foreign policy index: CAPE-VI calculates how foreign aid should be prioritised for countries that are at risk or already considered to be fragile. These countries are characterised by various forms of conflict, disadvantaged by extremes of climate change, poverty, human rights abuses, and suffering from internal warfare or terrorism

    Individual prognosis at diagnosis in nonmetastatic prostate cancer: Development and external validation of the PREDICT Prostate multivariable model.

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    BACKGROUND: Prognostic stratification is the cornerstone of management in nonmetastatic prostate cancer (PCa). However, existing prognostic models are inadequate-often using treatment outcomes rather than survival, stratifying by broad heterogeneous groups and using heavily treated cohorts. To address this unmet need, we developed an individualised prognostic model that contextualises PCa-specific mortality (PCSM) against other cause mortality, and estimates the impact of treatment on survival. METHODS AND FINDINGS: Using records from the United Kingdom National Cancer Registration and Analysis Service (NCRAS), data were collated for 10,089 men diagnosed with nonmetastatic PCa between 2000 and 2010 in Eastern England. Median follow-up was 9.8 years with 3,829 deaths (1,202 PCa specific). Totals of 19.8%, 14.1%, 34.6%, and 31.5% of men underwent conservative management, prostatectomy, radiotherapy (RT), and androgen deprivation monotherapy, respectively. A total of 2,546 men diagnosed in Singapore over a similar time period represented an external validation cohort. Data were randomly split 70:30 into model development and validation cohorts. Fifteen-year PCSM and non-PCa mortality (NPCM) were explored using separate multivariable Cox models within a competing risks framework. Fractional polynomials (FPs) were utilised to fit continuous variables and baseline hazards. Model accuracy was assessed by discrimination and calibration using the Harrell C-index and chi-squared goodness of fit, respectively, within both validation cohorts. A multivariable model estimating individualised 10- and 15-year survival outcomes was constructed combining age, prostate-specific antigen (PSA), histological grade, biopsy core involvement, stage, and primary treatment, which were each independent prognostic factors for PCSM, and age and comorbidity, which were prognostic for NPCM. The model demonstrated good discrimination, with a C-index of 0.84 (95% CI: 0.82-0.86) and 0.84 (95% CI: 0.80-0.87) for 15-year PCSM in the UK and Singapore validation cohorts, respectively, comparing favourably to international risk-stratification criteria. Discrimination was maintained for overall mortality, with C-index 0.77 (95% CI: 0.75-0.78) and 0.76 (95% CI: 0.73-0.78). The model was well calibrated with no significant difference between predicted and observed PCa-specific (p = 0.19) or overall deaths (p = 0.43) in the UK cohort. Key study limitations were a relatively small external validation cohort, an inability to account for delayed changes to treatment beyond 12 months, and an absence of tumour-stage subclassifications. CONCLUSIONS: 'PREDICT Prostate' is an individualised multivariable PCa prognostic model built from baseline diagnostic information and the first to our knowledge that models potential treatment benefits on overall survival. Prognostic power is high despite using only routinely collected clinicopathological information.The Urology Foundatio

    The Prostate Health Index adds predictive value to multi-parametric MRI in detecting significant prostate cancers in a repeat biopsy population

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    Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5-30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI

    Similar expression to FGF (Sef) inhibits fibroblast growth factor-induced tumourigenic behaviour in prostate cancer cells and is downregulated in aggressive clinical disease.

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    BACKGROUND: The fibroblast growth factor (FGF) axis is an important mitogenic stimulus in prostate carcinogenesis. We have previously reported that transcript level of human similar expression to FGF (hSef), a key regulator of this pathway, is downregulated in clinical prostate cancer. In this study we further analysed the role of hSef in prostate cancer. METHODS: hSef function was studied in in vitro and in vivo prostate cancer models using stable over-expression clones. Protein expression of hSef was studied in a comprehensive tissue microarray. RESULTS: Stable over-expression of hSef resulted in reduced in vitro cancer cell proliferation, migration and invasive potential. In an in vivo xenograft model, the expression of hSef significantly retarded prostate tumour growth as compared with empty vector (P=0.03) and non-transfected (P=0.0001) controls. Histological examination further showed a less invasive tumour phenotype and reduced numbers of proliferating cells (P=0.0002). In signalling studies, hSef inhibited FGF-induced ERK phosphorylation, migration to the nucleus and activation of a reporter gene. Constitutively active Ras, however, was able to reverse these effects, suggesting that hSef exerts an effect either above or at the level of Ras in prostate cancer cells. In a large tissue microarray, we observed a significant loss of hSef protein in high-grade (P<0.0001) and metastatic (P<0.0001) prostate cancer. CONCLUSIONS: Considered together, the role of hSef in attenuating FGF signalling and evidence of downregulation in advanced tumours argue strongly for a tumour suppressor function in human prostate cancer

    Inhibitory effect of HIV-specific neutralizing IgA on mucosal transmission of HIV in humanized mice

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    HIV-1 infections are generally initiated at mucosal sites. Thus, IgA antibody, which plays pivotal roles in mucosal immunity, might efficiently prevent HIV infection. However, mounting a highly effective HIV-specific mucosal IgA response by conventional immunization has been challenging and the potency of HIV-specific IgA against infection needs to be addressed in vivo. Here we show that the polymeric IgA form of anti-HIV antibody inhibits HIV mucosal transmission more effectively than the monomeric IgA or IgG1 form in a comparable range of concentrations in humanized mice. To deliver anti-HIV IgA in a continual manner, we devised a hematopoietic stem/progenitor cell (HSPC)–based genetic approach using an IgA gene. We transplanted human HSPCs transduced with a lentiviral construct encoding a class-switched anti-HIV IgA (b12-IgA) into the humanized bone marrow-liver-thymus (BLT) mice. The transgene was expressed specifically in B cells and plasma cells in lymphoid organs and mucosal sites. After vaginal HIV-1 challenge, mucosal CD4^+ T cells in the b12-IgA–producing mice were protected from virus-mediated depletion. Similar results were also obtained in a second humanized model, “human immune system mice.” Our study demonstrates the potential of anti-HIV IgA in immunoprophylaxis in vivo, emphasizing the importance of the mucosal IgA response in defense against HIV/AIDS

    A kapwa-infused paradigm in teaching Catholic theology/catechesis in a multireligious classroom in the Philippines

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    The increasing religious diversity in educational space has raised a legitimate question on how Catholic theology/ catechesis must be taught in Philippine Catholic universities given the institutional mandate to educate students “into the faith of the Church through teaching of Christian doctrine in an organic and systematic way” (Wuerl, 2013, 1). On this note, the paper makes reference to “centered plural- ism” (CP), a positional posture espoused by Georgetown University in dealing with this predicament. In an attempt to (re) appropriate CP into local context, there is a need to explore the Filipino conception of self/others as enveloped within the indigenous concept of kapwa. Hereon, the paper finds that CP is not just feasibly suitable in local context but with kapwa's more inclusive description of the relationship of self and others, a CP‐based teaching paradigm in theology/ catechesis is a promising project in the educational scene of the Philippines
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