Additional Year Of Exposure Research Articles

Childcare attendance and risk of infectious mononucleosis: A population-based Danish cohort study.

The risk of infectious mononucleosis (IM) is affected both by crowding and by sibship structure, i.e., number and signed age differential between an index child and a sibling. Siblings provide protection against IM by pre-empting delayed primary Epstein-Barr virus infection with its associated high risk of IM. The association between childcare attendance and risk of IM, on the other hand, has never been studied in a large, well-characterized cohort. Danish children born in July 1992 through 2016 with a completely known simple childcare attendance history before age 1.5 years (n = 908,866) were followed up for a hospital contact with an IM diagnosis at ages 1.5-26 years. Hazard ratios (HRs) of IM for an additional year of exposure were obtained from stratified Cox regression analyses, stratified by sex and year of birth, with age as the underlying time scale, adjusted for sibship structure, and sociodemographic variables including parental ethnicity and maternal age. An additional year of exclusively attending a daycare home (max 5 children) yielded HR = 0.90 (95% confidence interval 0.81-1.00), and similarly, each year of exclusively attending a childcare institution (e.g., crèche) yielded HR = 0.94 (0.84-1.06). Forwarding enrollment in childcare by a year lowers the risk of IM later in life much less than having an additional sibling of comparable age and has no practical public health implications. We find our results suggestive of a random threshold for successful Epstein-Barr virus infection that is more easily reached by a sibling than the collective of playmates in daycare homes or childcare institutions.

Transitions that Matter? Czechoslovakia's Break up and Human Stature.

Changes in a population’s average stature are virtuous pointers of wellbeing which are sensitive to improvements in psychosocial environments during childhood. A major structural change that could have altered an environment during childhood is the transition from communist to a liberal democracy, and, more specifically, the meltdown of the Soviet bloc provides for a quasi-natural experiment. This paper examines the trends in heights in the Czech Republic and Slovakia before and after the transition and the subsequent break-up of the Czechoslovakian federation. We find that one additional year of exposure to a liberal democracy while growing up is associated with an increasing population stature of 0.28 cm among Slovaks and 0.15 cm among Czechs. We only find changes in stature among men who are more sensitive to environmental stress, especially at the lower end of the current socio-economic status. Results are robust to alternative datasets and measures of democracy.

The Labor Market Consequences of Receiving Disability Benefits during Childhood

I estimate the labor market effects of gaining eligibility for Supplemental Security Income (SSI) disability benefits during childhood. A Supreme Court decision eased the criteria to be considered disabled, disproportionately affecting child applicants with mental disorders. For individuals with mental disorders, each additional year of exposure to eased standards during childhood increased their SSI receipt by 0.3 years. The additional benefit receipt reduced cumulative labor market earnings through age 30 by $1,600 for each additional year of exposure for those with mental disorders. Importantly, this does not address the full range of outcomes that may be affected by receiving benefits.

Developmental vulnerabilities in children of chronically ill parents: a population-based linked data study

BackgroundCurrently, there is mixed evidence regarding the effects on children when a parent is chronically ill. Research has also primarily been conducted with adolescent samples. This study investigated developmental vulnerabilities...

Ability Grouping in the Early Grades: Long-Term Consequences for Educational Equity in the United States

Background Ability grouping has resurged in U.S. schools despite long-standing debates over its consequences for educational equity. Proponents argue that it is the best response to variation in academic skills because it allows teachers to customize the content and pace of instruction to students’ diverse needs. Critics answer that this practice places students in divergent educational paths that reproduce educational and social inequalities. Despite the contested nature of ability grouping, research has yet to produce reliable longitudinal evidence to evaluate critics’ claims. Objective We examine the degree to which exposure to within-class grouping for reading instruction from kindergarten to third grade is predictive of students’ reading test scores and English coursework in the middle grades. Research Design We use multilevel achievement growth models predicting average reading achievement from kindergarten to eighth grade as a function of years of exposure in low, average, or high ability groups in kindergarten through third grade and control variables relevant to each grade. We evaluate the achievement differences between students who are grouped in these ability groups for one or more years and those who were never ability grouped. We use multinomial logistic regression models to estimate the degree to which number of years in each ability group in K–3 grades predicts placements in eighth-grade English classes (below grade or honors, as opposed to regular English classes). Data We use data from the Early Childhood Longitudinal Study–Kindergarten Cohort (ECLS–K), a national panel study of the 1998 U.S. kindergarten cohort sponsored by National Center for Education Statistics, U.S. Department of Education. Our sample consists of 7,800 students with data for fall of kindergarten, and spring of kindergarten and first, third, fifth, and eighth grades. Findings Compared with similar students who were ungrouped in the early grades, those in high-ability reading groups have higher test scores, whereas those in low-ability groups have lower test scores in every grade from kindergarten to the eighth grade. In addition, compared with their ungrouped counterparts, students in low-ability groups in the early grades are more likely to enroll in eighth grade English classes that are below grade level, whereas those in high-ability groups in these grades are more likely to enroll in honors eighth-grade English classes. Achievement gaps between previously grouped and ungrouped students increase with every additional year of exposure to ability grouping. Conclusions Students’ ability group placements in the early grades evolve into divergent educational paths that grow further apart with multiple years of grouping. These findings provide the first longitudinal evidence linking ability grouping to the reproduction of educational inequalities.

The impact of pharmacy-based immunization services on the likelihood of immunization in the United States

ObjectivesA major policy to increase immunization rates against infectious diseases in the United States has included pharmacy-based immunization services. We aimed to determine the impact of pharmacy-based immunization services on the likelihood of adult influenza and pneumococcal immunization. DesignNational individual-level immunization data were merged with pharmacy-level data on the availability of immunization services for 8466 pharmacies from a national pharmacy chain. County-level variation in availability of vaccines from 2006 to 2010 was used to characterize exposure to immunization services. We used a longitudinal logistic regression model to estimate the impact of pharmacy-based immunization services on the outcomes of interest. Setting and participantsWe conducted the main analysis in the U.S. adult population. We conducted subgroup analyses of high-risk populations, including people 65 years of age or older. Outcome measuresOdds of being immunized for influenza or pneumococcal disease after exposure to the service compared with before the service while controlling for existing trends in immunization rate growth and other confounders. ResultsEach additional year of exposure to pharmacy-based immunization services was associated with a 1.023 (CI 1.012–1.034) greater odds of reporting an influenza immunization and a 1.016 (CI 1.006–1.027) greater odds of reporting a pneumococcal immunization. Five years after national implementation, we estimate that 6.2 million additional influenza immunizations and 3.5 million additional pneumococcal immunizations are attributable to pharmacy-delivered immunization services each year. Subgroup analyses further indicate that the policy increased the odds of immunization for both diseases over time among adults 65 years of age or older (influenza odds ratio [OR] 1.025, CI 1.013–1.038; and pneumococcal OR 1.026, CI 1.010–1.042). ConclusionPharmacy-based immunization services increased the likelihood of immunization for influenza and pneumococcal diseases, resulting in millions of additional immunizations in the United States.

Sexual History Taking’– Difficulties Faced by Undergraduate Medical Students and their Preferred Teaching Learning Methods

Background: Sexual history taking (SHT) for instance is described as an important clinical skill that formal medical school curricula have historically neglected. However, such skill deficit might not be overcome even after graduation. The deficiency in learning SHT skills might eventually affect students’ career choices. Aim: To assess the difficulties faced by undergraduate medical students while eliciting sexual history and to identify the pitfalls and the students preferences in the teaching learning methods for taking sexual history perceived by the students. Methodology: A cross-sectional study was conducted in our medical college hospital between Jan 2016 and June 2016 involving the students of final year medical students and CRRI’S. Total numbers of participants were 220 students. Questions related to their comfort and confident level in eliciting sexual history along with general history, prerequisites in obtaining sexual history and the ideal age and gender according to the students perception was all obtained in the questionnaire. Questions for assessing the barriers in eliciting sexual history among the medical student’s and the current teaching methods which were followed for obtaining the sexual history was obtained. Likerts scale was used for assessing the student’s attitude towards asking the sexual history. Finally suggestions were also asked in improving the teaching methods for obtaining the sexual history. Results: The CRRI’s were found to be more confident in eliciting sexual history than the final year MBBS students, as they had one more additional year of exposure and females in both the groups were found to be slightly more confident than the males in eliciting the sexual history. Most of the students in both the groups felt that cultural and religious differences are the major barriers in eliciting the sexual history and they were also able to recognise their own limitations. Majority of the students agree to the point that they had not been adequately trained in eliciting sexual history. Students felt that they have to be taught by means of role play, video clips and simulated patients which would practically guide them in eliciting sexual history to the patient in a much more skilful and confident manner. Conclusions: Lack of confidence in approaching the subject of sexual health, inadequate preparation were some of the barriers identified. The delivery of sexual health education program should incorporate confidence building and to make students feel comfortable to take a sexual history from patients.

Early Life Exposure to Tap Water and the Development of Cognitive Skills

To improve drinking water accessibility and safety in rural China, the Chinese government launched the rural drinking water program in the 1980s. As part of the program, tap water infrastructure has been constructed in rural areas to supply tap water to rural residents. This policy intervention provides a unique opportunity to examine the impact of early life exposure to tap water on children’s cognitive achievement in later life. Using data extracted from the China Family Panel Studies (CFPS), we find that one additional year of exposure to tap water in early life increases average cognitive test score by 0.109 standard deviations for a sample of rural children aged 10-15 in 2010. The effect is larger for children whose fathers are less-educated. Event study estimates confirm that the beneficial impacts are concentrated in early life with limited additional impact after the time window.

Social constraints and women's education: Evidence from Afghanistan under radical religious rule

We analyze how growing up under Taliban rule affects Afghan women's educational attainments and subsequent labor market and fertility outcomes. While in power from 1996 to 2001, the Taliban ruled a large portion of the Afghan territory and introduced a ban on girls’ education. Using data from the National Risk and Vulnerability Assessment survey, we rely on the fact that, depending on their year of birth and province of residence, individuals differed in the number of years they were exposed to the Taliban government while of school age. Our difference-in-differences estimates show that an additional year of exposure to the Taliban occupation while of school age reduces a woman's probability of completing basic education by about two percentage points. The effects on educational outcomes are larger in Pashtun districts and rural areas. These findings are not due to the 1992 introduction of the provisional Islamist government that preceded the Taliban, cultural differences related to ethnicity, or varying emigration rates across provinces. The estimates are robust to differences across provinces in the number of violent events before, during, and after the Taliban occupation. Women exposed to the Taliban’s radical religious rule while they were of school age are also less likely to be employed outside of the household and more likely to have an agricultural job within the household. For fertility choices, exposure to the Taliban occupation increases total number of children and lowers age at first marriage. We discuss our empirical findings against theoretical economic literature on radical religious groups (e.g., Iannaccone, 1992; Berman, 2000).

Infant Health, Cognitive Performance and Earnings: Evidence from Inception of the Welfare State in Sweden

We estimate impacts of exposure to an infant health intervention trialled in Sweden in the early 1930s using purposively digitised birth registers linked to school catalogues, census files and tax records to generate longitudinal microdata that track individuals through five stages of the life-course, from birth to age 71. This allows us to measure impacts on childhood health and cognitive skills at ages 7 and 10, educational and occupational choice at age 16-20, employment, earnings and occupation at age 36-40, and pension income at age 71. Leveraging quasi-random variation in eligibility by birth date and birth parish, we estimate that an additional year of exposure was associated with improved reading and writing skills in primary school, and increased enrolment in university and apprenticeship in late adolescence. These changes are larger and more robust for men, but we find increases in secondary school completion which are unique to women. In the longer run, we find very substantial increases in employment (especially in the public sector) and income among women, alongside absolutely no impacts among men. We suggest that this may be, at least in part, because these cohorts were exposed to a massive expansion of the Swedish welfare state, which created more jobs for women than for men.

Welded, sandblasted, stainless steel corrugated bars in non-carbonated and carbonated mortars: A 9-year corrosion study

Three different stainless steel corrugated grades (UNS S20430, S30403 and S32205) were similar welded to stainless steel bars with the same composition and dissimilar welded to carbon steel (CS). After cleaning the welding oxides by sandblasting, the reinforcements were embedded in mortar with chlorides and some of the samples were carbonated. Corrosion activity was monitored using corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS). After 8 years of exposure, the samples were anodically polarized. Visual evaluation of the attack was performed after another additional year of exposure. Similar welded stainless steels offer a good durability if they have been sandblasted, except for S20430 when it is embedded in carbonated mortar with chlorides. Dissimilar welded steels are active since the beginning of the exposure for both studied conditions, but sandblasting reduces the corrosion rate of CS compared to non-welded CS bars.

Abstract A27: Association between diabetes pharmacotherapies and bladder cancer: A Medicare epidemiologic study

Abstract Background: Patients with type two diabetes mellitus (T2DM) have an increased risk of bladder cancer; they are also commonly treated with pioglitizone and angiotensin receptor blockers (ARBs), medications associated with an increased cancer risk in some studies. This study aimed to further explore the relationship between these medications and bladder cancer in an older population with higher baseline risk of this cancer and common exposure to these drugs. We examine the risk associated with exposure to the individual drug/drug class, and risk associated with exposure to both to assess for a potential cancer promoting interaction. Methods: Using a 40% Medicare random sample denominator and corresponding inpatient, outpatient (2004-2012) and prescription (2006-2012) claims, we studied fee-for-service beneficiaries age 67 and older. We identified pharmacotherapeutically treated diabetics (2006 to 2011) defined as patients filling one or more prescription for an oral hypoglycemic drug. Individual-level, time varying exposure to all oral and injectable hyopglycemics as well as ARBs and ACE-Is was calculated as count of drug-specific daily doses; daily doses were derived empirically as the median daily dose (MDDs) for this population. Cox proportional hazards models, adjusted for patient characteristics, comorbidities and diabetes complications, were used to examine the risk of incident bladder cancer associated with cumulative observed exposure to pioglitazone and ARBs. To address possible indication bias for the exposures of interest, we also estimated risk associated ACE-I exposure and non-pioglitazone TZD exposure, substitutes for the exposures of interest not suspected of increasing cancer risk. Interaction terms estimated the effect of exposure to ARBs with pioglitazone and ARBs with non-pioglitazone TZD. Secondary models repeated main models stratified on gender due to the higher baseline risk of bladder cancer in men. Results: Overall, we identified 1,161,443 diabetics, 62.5% female, 10.7% black, 9.8% Hispanic. Mean age at the beginning of follow-up was 75.1 years (SD 7.5); 18.9% had evidence of current or past tobacco use. Mean follow time was 42.2 months (SD 26.4). Overall, 20.2% of the cohort used some pioglitazone (mean exposure 642 MDDs); 31.7% used some ARB (Mean exposure 745 MDDs); 10.4% used some non-pioglitazone TZD (mean exposure 503 MDDs); 59.1% used some ACE-I (mean exposure 855 MDDs). 8.0% used both pioglitazone and ARBs; 13.2% used both pioglitazone and ACE-I; 4.1% used non-pioglitazone TZD and ARB; and 6.8% used non-pioglitazone TZD and ACE-I. In total, 5,874 bladder cancers were identified, 69% amongst men, an incidence of 0.28/1000 PY in men and 0.07/1000 PY in women. Compared to no observed exposure, the risk of bladder cancer associated with each additional year of exposure at median daily dose was: 0.97 (95% CI 0.89, 1.06) for pioglitazone, 1.04 (95% CI 0.97, 1.12) for ARBs; 0.99 (95% CI 0.95, 1.03) for ACE-Is and 0.98 (95% CI 0.86, 1.12) for non- pioglitizone TZDs. The risk of bladder cancer associated with each additional year of exposure to both pioglitizone and ARB was 0.97 (95% CI 0.91, 1.04); for pioglitazone and ACE-I, 1.01 (95% CI 0.98, 1.03); for non-pioglitazone TZD and ARB, 0.99 (95% CI 0.91, 1.08); and for non-pioglitazone TZD and ACE-I, 0.99 (95% CI 0.93, 1.04). Results did not differ when stratified by sex. Conclusions: We found no increased risk of bladder cancer associated with pioglitizone use, ARB use or exposure to both over an average observation time of 3.5 years. While the findings of this observational study should be confirmed in a prospective trial of longer duration, overall the results should reassure diabetics and their clinicians using these products to minimize the substantial health risks associated with diabetes. Citation Format: Jeremy Smith, Rebecca Zaha, Todd A. Mackenzie, Margaret R. Karagas, Nancy E. Morden. Association between diabetes pharmacotherapies and bladder cancer: A Medicare epidemiologic study. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A27.

A Prospective Cohort Study of Neurocognitive Function in Aviremic HIV-Infected Patients Treated With 1 or 3 Antiretrovirals

The evolution of neurocognitive performance in aviremic human immunodeficiency virus (HIV)-positive patients treated with <3 antiretrovirals is unknown. We prospectively included aviremic (≥1 year) HIV-positive patients, without concomitant major neurocognitive confounders, currently receiving boosted lopinavir or darunavir as monotherapy (n = 67) or triple antiretroviral therapy (ART) (n = 67) for ≥1 year. We evaluated neurocognitive function (7 domains) at baseline and after 1 year. We performed analysis of covariance to evaluate if 1 additional year of exposure to monotherapy compared with triple ART had an effect on Global Deficit Score (GDS) changes after adjustment for potential confounders. We also compared the evolution of neurocognitive performance and impairment rates. Intention-to-treat analysis showed that monotherapy did not influence 1-year GDS change after adjustment for significant confounders (age, ethnicity, duration of therapy, hepatitis C virus status, and HOMA-IR index); the adjusted effect was -0.04 (95% confidence interval, -.14 to .05; P = .38). Neurocognitive stability was observed with monotherapy and triple therapy (GDS crude mean change, -0.09 [95% confidence interval, -.16 to -.01] vs -0.08 [-.14 to -.02]), after 1 year of follow-up, similar proportions of patients changed neurocognitive status from impaired to unimpaired (monotherapy, 4 of 18 [22.2%]; triple therapy, 4 of 19 [21.1%]; P = .91) and vice versa (monotherapy, 5 of 44 [10.2%] and triple therapy, 3 of 45 [6.3%]; P = .48). Similar results were observed in an on-treatment analysis and with use of clinical ratings instead of GDS changes. The number of antiretrovirals included in the ART regimen does not seem to influence the evolution of neurocognitive function in HIV-infected patients with suppressed plasma viremia.

The divorce revolution and generalized trust: Evidence from the United States 1973–2010

This paper examines the effect of exposure to a culture of easier divorce as a minor on generalized trust using the General Social Survey from 1973 to 2010. The easier divorce culture is defined as the introduction of no-fault including unilateral divorce reforms across the US. According to the results, the divorce revolution seems to have had some effect on trust levels across the US. While there are no discernible effects for the whole sample of men, there are statistically significant effects for women with an additional year of exposure being associated with a 4 percentage point lower generalized trust in the states with easy divorce culture compared to states with fault based divorce culture. An analysis by sub-group of women indicates that married and divorced/separated women have significantly lower levels of trust associated with exposure to easy divorce culture as a child. The findings are in agreement with the predictions of previous literature regarding no-fault divorce reforms reducing the security offered by marriage, in particular for women.

The Divorce Revolution and Generalized Trust: Evidence from the United States 1973-2010

This paper examines the effect of exposure to a culture of easier divorce as a minor on generalized trust using the General Social Survey from 1973-2010. The easier divorce culture is defined as the introduction of no-fault including unilateral divorce reforms across the US. According to the results, the divorce revolution seems to have had some effect on trust levels across the US. While there are no discernible effects for the whole sample of men, there are statistically significant effects for women with an additional year of exposure being associated with a 4 percentage point lower generalized trust in the states with easy divorce culture compared to states with fault based divorce culture. An analysis by sub-group of women indicates that married and divorced/separated women have significantly lower levels of trust associated with exposure to easy divorce culture as a child. The findings are in agreement with the predictions of previous literature regarding no-fault divorce reforms reducing the security offered by marriage, in particular for women.

Risk of Cardiovascular Disease from Antiretroviral Therapy for HIV: A Systematic Review

BackgroundRecent studies suggest certain antiretroviral therapy (ART) drugs are associated with increases in cardiovascular disease.PurposeWe performed a systematic review and meta-analysis to summarize the available evidence, with the goal of elucidating whether specific ART drugs are associated with an increased risk of myocardial infarction (MI).Data SourcesWe searched Medline, Web of Science, the Cochrane Library, and abstract archives from the Conference on Retroviruses and Opportunistic Infections and International AIDS Society up to June 2011 to identify published articles and abstracts.Study SelectionEligible studies were comparative and included MI, strokes, or other cardiovascular events as outcomes.Data ExtractionEligibility screening, data extraction, and quality assessment were performed independently by two investigators.Data SynthesisRandom effects methods and Fisher’s combined probability test were used to summarize evidence.FindingsTwenty-seven studies met inclusion criteria, with 8 contributing to a formal meta-analysis. Findings based on two observational studies indicated an increase in risk of MI for patients recently exposed (usually defined as within last 6 months) to abacavir (RR 1.92, 95% CI 1.51–2.42) and protease inhibitors (PI) (RR 2.13, 95% CI 1.06–4.28). Our analysis also suggested an increased risk associated with each additional year of exposure to indinavir (RR 1.11, 95% CI 1.05–1.17) and lopinavir (RR 1.22, 95% CI 1.01–1.47). Our findings of increased cardiovascular risk from abacavir and PIs were in contrast to four published meta-analyses based on secondary analyses of randomized controlled trials, which found no increased risk from cardiovascular disease.ConclusionAlthough observational studies implicated specific drugs, the evidence is mixed. Further, meta-analyses of randomized trials did not find increased risk from abacavir and PIs. Our findings that implicate specific ARTs in the observational setting provide sufficient evidence to warrant further investigation of this relationship in studies designed for that purpose.

Physical Activity and Positive Youth Development: Impact of a School-Based Program

Protective factors associated with positive youth development predict health and education outcomes. This study explored trends in these protective factors and in physical activity among low-income students, and determined the impact of a school-based youth development program on these trends. This study used a quasi-experimental time series design including data from 158 low-income schools from 2001 to 2007. Ninety-four schools had exposure to a school-based program promoting physical activity and youth development through structured play; 64 schools served as controls. Primary outcomes were 5th-grade student scores (n = 13,109) on a California statewide survey for physical activity (1-6 scale) and measures of protective factors including problem solving skills, meaningful participation in school, and caring adults (1-4 scales). Predictors were time (year) and school's number of years of exposure to the program. Overall, significant annual declines were seen in protective factors, including students' report of feeling safe (-0.03, 95% CI [-0.03, -0.01]), caring adults at school (-0.03 [-0.05, -0.02]), and problem solving skills (-0.03 [-0.04, -0.02]). Cumulative declines over 6 years were equivalent to a drop of 1 school-level SD. Each additional year of exposure to the program predicted greater meaningful participation (0.02 [0.001, 0.5]), problem-solving skills (0.03 [0.0001, 0.06]), and increased physical activity (0.06 [0.01, 0.10]); exposure throughout elementary school (6 years) increased scores by 1 school-level SD. Low-income students reported a significant decline in protective factors since 2001. School partnerships with youth development programs promoting physical activity may ameliorate declines in emotional well-being and increase physical activity.

Immunodeficiency as a Risk Factor for Non-AIDS-Defining Malignancies in HIV-1-Infected Patients Receiving Combination Antiretroviral Therapy

The aim of this study was to investigate the association between immunodeficiency, viremia, and non-AIDS-defining malignancies (NADM). Patients starting combination antiretroviral therapy (cART) as of 1 January 1996 were selected from the AIDS Therapy Evaluation in the Netherlands (ATHENA) cohort. In Cox models, risk factors for NADM were investigated. These included age, sex, transmission route, smoking, alcohol abuse, prior AIDS diagnosis, duration of exposure to cART, and estimated duration of human immunodeficiency virus infection. CD4+ cell count and viral load (VL) were considered as time-updated variables and as measures of cumulative exposure to CD4+ cell counts of < 200, < 350, or < 500 cells/mm³ and detectable VL >50, >400, and >1000 copies/mL, respectively. In a cohort of 11,459 patients, 236 NADMs were diagnosed; 102 were caused by infection, and 134 were attributable to other causes. Median CD4+ cell count at NADM diagnosis was 340 cells/mm³ (range, 210-540 cells/mm³). Median time to first NADM after starting cART was 5.0 years (range, 2.2-8.2 years). In multivariate models, cumulative exposure to CD4+ cell counts < 200 cells/mm³ remained significant (hazard ratio [HR], 1.12; range, 1.03-1.22) for each additional year of exposure. In stratified analyses, cumulative exposure to CD4+ cell counts < 200 cells/mm³ was associated with malignancies possibly caused by infection (HR, 1.16; range, 1.03-1.31]) but was not associated with other types of cancers. No significant effect of viremia was seen in either type of cancer. Cumulative exposure to CD4+ cell counts < 200 cells/mm³ during cART was associated with an increased risk of infection-related non-AIDS-defining malignancies.

The Association between Prolonged Occupational Exposure to Paraphenylenediamine (Hair-dye) and Renal Impairment

Paraphenylenediamine (PPD) is widely used in hair dyes and cosmetic skin application. PPD intoxication following oral ingestion could be an important cause of ARF in Sudan, Morocco and the Indian Subcontinent. Repeated and prolonged exposure to PPD may also be associated with Chronic Kidney Disease (CKD). This is a cross-sectional study that covered six conveniently-chosen hairdressing saloons in Khartoum, Sudan. Hairdressers with regular professional exposure to PPD were evaluated for the presence of renal impairment (serum creatinine > or = 2 mg/dl) and other markers of kidney damage. The study included seventy-two females with a mean age of 40 +/- 8 years and a median duration of exposure to PPD of 6 years. Renal impairment, proteinuria and hematuria were observed in 14%, 26.4% and 41.1% of hair dressers, respectively. Hypertension, skin changes and bronchospasm were found in 19.4%, 38.9% and 22% of participants, respectively. Using pure forms of PPD significantly increased the risk of having elevated serum creatinine (OR 5.9; P = 0.02) and proteinuria (OR 9.8; P = 0.002) compared to manufactured forms with lower concentrations. Each additional year of exposure to PPD significantly increased the risk of having elevated serum creatinine (OR 1.3; P = 0.01), proteinuria (OR 1.4; P = 0.001) and hematuria (OR 1.1; P = 0.04). In this group of hairdressers with regular exposure to PPD, we observed high prevalence of renal impairment, proteinuria and hematuria. These findings were significantly associated with the use of pure forms of PPD and longer duration of exposure.

Effect of host size and temporal exposure on metacercarial infection levels in the intertidal cockle Cerastoderma edule

In a field survey and a field experiment the relative importance of host size and temporal exposure in determining metacercarial infection levels in an intertidal bivalve was investigated. While cockles (Cerastoderma edule) of different age (indicated by winter rings on shells) collected at the same site showed strong positive correlations between host size and infection levels over the total sample, correlations were weak or absent within the age groups. Mean infection levels in cockles strongly increased with age suggesting temporal exposure and not size to be the main determinant of infection levels in the cockles. This was supported by a field experiment in which small and large cockles were exposed for one or two months on a tidal flat. While infection levels significantly increased with temporal exposure, host size had no significant effect. This suggests that bivalve hosts on temperate tidal flats accumulate parasites during a distinctive infection window during summer more or less independent of their size. With every additional year of exposure, infection levels of the parasites increase. Hence, it is important to take host age into account when comparing individual infection levels within and among different host populations.