550 research outputs found

    Clinical Factors Associated with Long-Term Complete Remission versus Poor Response to Chemotherapy in HIV-Infected Children and Adolescents with Kaposi Sarcoma Receiving Bleomycin and Vincristine: A Retrospective Observational Study

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    Kaposi sarcoma (KS) is the most common HIV-associated malignancy in children and adolescents in Africa. Pediatric KS is distinct from adult disease. We evaluated the clinical characteristics associated with long-term outcomes. We performed a retrospective observational analysis of 70 HIV-infected children and adolescents with KS less than 18 years of age diagnosed between 8/2010 and 6/2013 in Lilongwe, Malawi. Local first-line treatment included bleomycin and vincristine plus nevirapine-based highly active anti-retroviral therapy (HAART). Median age was 8.6 years (range 1.7-17.9); there were 35 females (50%). Most common sites of presentation were: lymph node (74%), skin (59%), subcutaneous nodules (33%), oral (27%), woody edema (24%), and visceral (16%). Eighteen (26%) presented with lymphadenopathy only. Severe CD4 suppression occurred in 28%. At time of KS diagnosis, 49% were already on HAART. Overall, 28% presented with a platelet count \u3c 100 x 109/L and 37% with hemoglobin \u3c 8 g/dL. The 2-year event-free (EFS) and overall survival (OS) were 46% and 58% respectively (median follow-up 29 months, range 15-50). Multivariable analysis of risk of death and failure to achieve EFS demonstrated that visceral disease (odds ratios [OR] 19.08 and 11.61, 95% CI 2.22-163.90 and 1.60-83.95 respectively) and presenting with more than 20 skin/oral lesions (OR 9.57 and 22.90, 95% CI 1.01-90.99 and 1.00-524.13 respectively) were independent risk factors for both. Woody edema was associated with failure to achieve EFS (OR 7.80, 95% CI 1.84-33.08) but not death. Univariable analysis revealed that lymph node involvement was favorable for EFS (OR 0.28, 95% CI 0.08-0.99), while T1 TIS staging criteria, presence of cytopenias, and severe immune suppression were not associated with increased mortality. Long-term complete remission is achievable in pediatric KS, however outcomes vary according to clinical presentation. Based on clinical heterogeneity, treatment according to risk-stratification is necessary to improve overall outcomes

    Machine Learning in Automated Text Categorization

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    The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert manpower, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey

    Integrative taxonomy versus taxonomic authority without peer review: the case of the Oriental fruit fly, Bactrocera dorsalis(Tephritidae)

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    1. Major global horticultural and food security tephritid fruit fly pests,Bactrocera papayae(papaya fruit fly) andB. invadens(invasive fruit fly), weresynonymised withB. dorsalis(Oriental fruit fly) by Schutzeet al.(2015a) based onextensive integrative taxonomic evidence from multiple sources. This synonymy waspeer reviewed by eight independent experts.2. Drew & Romig (2016) withdrewB.papayaeandB.invadensfrom synonymy based onopinion drawn primarily from disparate geographical distribution, morphological, andhost use information. This reversal was not subjected to peer review.3. We consider the withdrawal from synonymy as invalid due to significant errors andmisrepresentations of the literature provided in the arguments of Drew & Romig (2016)that we propose would not have withstood peer scrutiny.4. This case reflects a broader issue of individual taxonomic authorities using opinionto challenge extensive evidence generated via scientific hypothesis-testing methods bydiscipline specialists.5. We recommend that taxonomic acts not subjected to peer review, especially of pestspecies, be actively discouraged by the broader scientific and regulatory community

    Reciprocity? International Preceptors’ Perceptions of Global Health Elective Learners at African Sites

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    Background: Short-term global health electives (STGHEs) have become increasingly common, with evidence showing educational and clinical benefits for short-term learners (STLs). Despite increased recognition that STGHEs should be mutually beneficial for host sites and STLs, evidence demonstrating the impact on international host preceptors is lacking. Objectives: To understand international host preceptors’ perceptions regarding benefits and burdens of hosting STLs. Methods: Focus group discussions with a convenience sample of 10 of 18 eligible preceptors were conducted at pediatric STGHE sites in Malawi and Lesotho. Qualitative content analysis was performed to identify themes using a deductive-inductive approach. Findings: Common themes regarding benefits to preceptors included increased knowledge and resources for learning from STLs, broadened differential diagnoses, and the satisfaction of teaching. Regarding burdens, preceptors perceived that supervising STLs decreases efficiency. Preceptors identified the burden of having to intervene in instances that could lead to patient harm. Some preceptors perceived that STLs under-valued preceptors’ clinical decision-making in resource-limited contexts. Conclusions: Our findings emphasize the need for institutions to identify mutuality of benefits between STLs and host sites when developing STGHEs. Host preceptors identified robust pre-departure training for STLs, lengthened duration of STGHEs, and formal preceptor orientation as ways to enhance mutuality of benefits

    Vaccine delivery by penetratin: mechanism of antigen presentation by dendritic cells

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    Cell-penetrating peptides (CPP) or membrane-translocating peptides such as penetratin from Antennapedia homeodomain or TAT from human immunodeficiency virus are useful vectors for the delivery of protein antigens or their cytotoxic (Tc) or helper (Th) T cell epitopes to antigen-presenting cells. Mice immunized with CPP containing immunogens elicit antigen-specific Tc and/or Th responses and could be protected from tumor challenges. In the present paper, we investigate the mechanism of class I and class II antigen presentation of ovalbumin covalently linked to penetratin (AntpOVA) by bone marrow-derived dendritic cells with the use of biochemical inhibitors of various pathways of antigen processing and presentation. Results from our study suggested that uptake of AntpOVA is via a combination of energy-independent (membrane fusion) and energy-dependent pathways (endocytosis). Once internalized by either mechanism, multiple tap-dependent or independent antigen presentation pathways are accessed while not completely dependent on proteasomal processing but involving proteolytic trimming in the ER and Golgi compartments. Our study provides an understanding on the mechanism of antigen presentation mediated by CPP and leads to greater insights into future development of vaccine formulations

    Routine Inpatient HIV Testing System Increases Access to Pediatric HIV Care in sub-Saharan Africa

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    Routine HIV testing, called provider-initiated opt-out HIV testing and counseling (PITC), is recommended in African countries with high HIV prevalence. However, it is unknown whether PITC increases access to pediatric HIV care. In 2008 the Baylor International Pediatric AIDS Initiative implemented PITC (BIPAI-PITC) at a Malawian hospital. We sought to evaluate the influence of BIPAI-PITC, compared to non-routine HIV testing (NRT), on pediatric HIV care access
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