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The relationship between urinary organophosphate pesticide residues and reproductive development among boys living in the rural Western Cape
Get PDFBackground: Many contemporary agricultural pesticides are hormonally active, but few previous studies have investigated their effect on the reproductive health and growth of pubertal boys. A previous analysis found significant differences in serum reproductive hormone levels and lower anthropometric measurements as well as non-significant lower sexual maturity ratings and testicular sizes in farm boys compared to non-farm boys from the rural Western Cape in South Africa. Methodology: This analysis included 183 out of 269 school boys residing on farms and neighbouring nonfarming areas who provided urine samples in a cross-sectional study. Measurements included a questionnaire, clinical assessment of sexual maturity development (SMD), anthropometric measurements (height, weight and body mass index (BMI)), serum reproductive hormones (including luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and oestradiol (E2)) and urinary levels of 3 dialkyl phosphates (organophosphate pesticide metabolites) including di-ethyl, di-methyl and di-methyl triphosphate (DEP, DMP and DMTP). Results: The median (interquartile range) of age and sum dialkyl phosphates of the school boys was 12 years (9-13 years) and 68.3 ng/mL (27.9-129.5 ng/mL) respectively. There were consistent, mostly non-significant associations with some dose response relationships between urinary levels of dialkyl phosphates and adverse effects on outcomes including SMD, serum reproductive hormones and anthropometric development. The strongest results included a strong positive association and dose response found between serum oestradiol > the 50th percentile and quartiles DMTP (odd ratio and confidence interval for highest and lowest quartile: 7.4; 1.7-32.4) and between BMI <50th percentile and quartiles of DMTP (odd ratio and confidence interval for highest and lowest quartile: 3.2; 1.2-9.0). Conclusion: The results provide some preliminary evidence that organophosphate pesticides exposure could alter the reproductive hormone levels and adversely affect the body size of school boys. There was also lack of evidence of other adverse effects on reproductive development. These findings require further investigation in a larger longitudinal study with seasonal bio-monitoring for pesticides
HIV-associated Neuropathy and Autonomic Dysfunction in South Africans on established ART impacts daily living
Get PDFIntroduction A common complication of Human Immunodeficiency Virus (HIV) and anti-retroviral therapy (ART) is distal sensory polyneuropathy (DSP). Older age and previous TB are risk factors for DSP among HIVinfected Africans before and shortly after ART initiation. Little is known about autonomic dysfunction in Africans on long-term ART and the impact of DSP and autonomic impairment on their quality of life. Our aim was to describe the frequency, characteristics and functional consequences of DSP and autonomic dysfunction in a healthy HIV-infected community-based cohort after at least 5 years of ART. Methods HIV-infected South Africans on the government-sponsored ART program for at least 5 years were included in this cross-sectional analysis. Each consenting participant underwent a focussed neurological assessment using the Brief Peripheral Neuropathy Screen (BPNS) and a reduced version of the Total Neuropathy Score (rTNS). DSP was defined as the presence of at least 2 neuropathic signs in a distal and symmetrical distribution, and symptomatic DSP (SDSP) when accompanied by neuropathic symptoms. Heart rate variability and orthostatic hypotension were measured as described by the Ewing classic battery, and the Survey of Autonomic Symptoms (SAS) questionnaire assessed the presence and severity of autonomic symptoms. We used a modified version of the Lower Extremity Functional Scale (LEFS) to assess lower limb physical ability. Results The 67 participants had a median age of 41 years (interquartile range (IQR) 36-46) and 61 (91 %) were women. The median duration of ART was 7 years (IQR 6-10). DSP criteria were met in 54 (80.6%) and 24 (44.4%) had symptomatic DSP. Comparing participants with DSP to those without DSP, there was no difference in sex (P=0.39), age (P=0.79), current CD4 (P=0.69), viral suppression (P=0.34), ART duration (P=0.22) or previous tuberculosis (TB) (P=0.72) in those with DSP. Similar outcomes were obtained for SDSP. Abnormal autonomic tests were present in 60%. Those with SDSP had more severe autonomic symptoms than those with asymptomatic DSP (P=0.0008). We found that those with DSP and SDSP had significantly lower LEFS percentage scores than those without (P=0.039 and P=0.013 respectively). 5 Conclusion DSP remains a common complication of HIV in the modern era of ART and can lead to significant functional impairment. Autonomic dysfunction is prevalent in SDSP
A cross-sectional study of Ig-E mediated food sensitisation and food allergy in an unselected population of South African children aged 12-36 months
No full textIncludes bibliographical references.Background: Food allergy (FA) is a significant and often life-threatening health problem affecting about 4-6% of children and their families globally. In some developed countries FA prevalence has reached 10% and it is believed that developing economies may follow a similar trend since there is a reported rise in the global burden of other allergic diseases like asthma, allergic rhinitis and eczema. However, there is a dearth of population studies at global level documenting challenge-proven Ig-E mediated food allergy (FA) prevalence. As such, we studied an unselected population of children attending crèches in Cape Town, South Africa. Methodology All children aged 12-36 months attending the selected crèches between February 2013 and October 2013 were eligible for the study. Participants were assessed with an allergy questionnaire, had skin prick tests (SPTs) done and if they qualified, were invited for an oral food challenge (OFC) at the Red Cross Hospital Paediatric Allergy Clinic (RCHPAC). The SPT wheal size results were categorised into ≥1mm, ≥3mm and ≥7mm. We gave a general description of the study sample with respect to the demographic characteristics and compared participants and non-participants. We reported sensitisation pattern towards foods in the panel i.e. egg white extract, peanut, cow’s milk, wheat(flour), soy, hazelnut and fish (cod) according to the SPT categories. The effects of age, ethnicity, sex and concomitant allergy on sensitisation patterns were assessed. Associations between the potential predictor variables and sensitisation were assessed by Z-test for proportions and Chi-square/Fisher’s exact. PART I presents the study protocol with a brief motivation for the relevance of the study and the methodology used. PART II presents a structured literature review on FA and FS in large populations of selected and unselected cohorts. It provides an overview of empirical evidence on prevalence estimates from both the developed and developing world, and the potential risk factors causing Fav. PART III summarises the methodology, results and interpretation of the analysis conducted in a journal-ready manuscript according to Current Allergy and Clinical Immunology Journal requirements. Results The sample consisted of; 39% black African, 20% Caucasian and 41% mixed race participants, with a median age 26 months (IQR: 22-31). Amongst 121 participants (66% response rate, 92% participation rate and 94% completion rate), the prevalence of SPT≥1mm to any food was 16%, SPT≥3mm 12% and SPT≥7mm 4%. The prevalence of challenge-proven Ig-E mediated raw egg allergy was 1.7% and peanut allergy 0.8%. Black African participants had higher sensitisation rates (23%) of SPT≥1mm to any food, when compared to Caucasian (13%) and mixed race (10%) participants despite the difference not reaching statistical significance (p=0.17). Conclusions: This study was acceptable and feasible in this population that has a low prevalence of Ig-E mediated FA that is comparable to other studies from developed countries using objective measures in unselected cohorts. The prevalence of FS is appreciably high in this sample and there are ethnic differences that require further investigation. The findings seem to suggest an existing burden of Ig-E mediated FAs in the South African context that is un-diagnosed and therefore not manage
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Infant and Childhood Infective Endocarditis in the Western Cape, South Africa: A Retrospective Review
Get PDFIntroduction Infective endocarditis is a microbial infection of the endothelial surface of the heart, predominantly the heart valves, that is associated with high mortality and morbidity. Few contemporary data exist regarding affected children in our context. Aims and Objectives: We aimed to describe the profile and treatment outcomes of infant and childhood endocarditis at our facilities. Methods: This is a retrospective review of infants and children with endocarditis at two public-sector hospitals in the Western Cape Province of South Africa over a 5-year period. Patients with “definite” and “possible” endocarditis according to Modified Duke Criteria were included in the review. Results: Forty-nine patients were identified for inclusion; 64% of patients met “definite” and 36% “possible” criteria. The in-hospital mortality rate was 20%; 53% of patients underwent surgery with a post-operative mortality rate of 7.7%. The median interval from diagnosis to surgery was 20 days (interquartile range 9-47 days). Valve replacement occurred in 28% and valve repair in 58%. There was a significant reduction in valvular dysfunction in patients undergoing surgery and only a marginal improvement in patients treated medically. Overall, 43% of patients had some degree of residual valvular dysfunction. Conclusion: Endocarditis is a serious disease with a high in-hospital mortality and presents challenges in making an accurate diagnosis. Despite a significant reduction in valvular dysfunction, a portion of patients had residual valvular dysfunction. Early surgery is associated with a lower mortality rate, but a higher rate of valve replacement when compared to delayed surgery
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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