4,216 research outputs found
Exposure to polychlorinated biphenyls and hexachlorobenzene, semen quality and testicular cancer risk
PURPOSE: We carried out a case-control study to investigate the possible role of occupational and environmental exposure to endocrine disruptors in the onset of testicular cancer (TC).
METHODS: We evaluated 125 TC patients and 103 controls. Seminal fluid examination and organochlorine analysis were performed in all subjects. Cases and controls were also interviewed using a structured questionnaire to collect demographic information, residence, andrological medical history and dietary information.
RESULTS: We found that a higher level of reproductive tract birth defects was associated with a higher risk of TC. With regard to diet, cases reported a higher consumption of milk and dairy products than controls. Overall, there was a statistically significant increase in TC risk in cases with detectable values of total polychlorinated organic compounds against controls (14.4 vs. 1.0 %; p < 0.001). TC patients with detectable levels of organochlorines had lower mean semen parameters than those with undetectable levels, although this difference was not statistically significant.
CONCLUSION: The International Agency for Research on Cancer recently included dioxin-like polychlorinated biphenyls (PCBs) in Group 1 of known human carcinogens. Our study confirmed and identified various risk factors for testicular cancer: cryptorchidism, consumption of milk and dairy products, parents' occupation and serum concentration of hexachlorobenzene and PCBs and, for the first time, we showed the correlation between semen quality and the serum concentration of these pollutants
Effects of two different blends of naturally mycotoxin-contaminated maize meal on growth and metabolic profile in replacement heifers.
The aim of this trial was to assess the effects of the administration of different combinations of mycotoxins in naturally contaminated maize grains on dairy heifer growth, blood measurements and puberty onset. A total of 35 Friesian female heifers were randomly allotted to three experimental groups from 18-21 to 42-45 weeks of age. During the 24-week experimental period (EP), heifers were fed the same diet, but with maize meal derived from three differently contaminated lots: very low contamination, as control (C); medium-low aflatoxin-contaminated (A); and mixed aflatoxin-fumonisin contaminated (A-F). At the end of the EP, they returned to a common diet without contaminated maize, and they were monitored for an additional period of 12 weeks (post-experimental period, PEP). BW, wither height, hip height, body length and heart girth were measured every 4 weeks from the beginning of EP to the end of PEP. At the same time, body condition score was evaluated and blood samples were taken from the jugular vein to be analysed for haematological, serum protein and metabolic profiles. Age at puberty was assessed by measuring weekly plasma progesterone levels from 40 to 52 weeks of age. Body growth measurements were processed both by ANOVA of average daily gain of EP and PEP separately, and by the analysis of growth curve parameters. Haematological, serum protein and metabolic profile were evaluated using a mixed model, taking into account the repeated measurements in time on each animal. Heifers' growth was delayed both in A and A-F groups during EP, as evidenced by the different linear coefficients of the BW growth curve in the three groups. Differently contaminated diets did not affect the haematological profile, so that it can be concluded that these levels of mycotoxin contamination do not determine any specific effect on haematopoiesis and immunity in growing heifers. The main blood marker of mycotoxin chronic toxicity was the γ-glutamyl transferase activity level in plasma, which appeared to be altered even after the removal of mycotoxins. During EP, plasma glucose was lower in the groups fed contaminated diet compared with C. The joint actions of an altered nutritional status and a long-lasting liver damage were probably the causes of the delay in puberty attainment in A and, particularly, in the A-F group. The results from this trial evidenced that a chronic aflatoxin-fumonisin contamination in diets of dairy heifers can determine an important delay in the reproductive career of these animals
Effects of summary knowledge of results in motor skills acquisition
The effects of Summary Knowledge of Results (KR) were tested, using 30 volunteers and a positioning task in which a tennis ball had to be transported in 30 trials, following a specific sequence and with a target time of 3000 msec. Ten minutes after the acquisition phase, the transfer test was performed with 10 trials of different sequences and target times. The retention test took place 24 hours later with 10 trials of the same sequence and target time as the acquisition phase. In the transfer and retention tests, KR was not provided. The volunteers were randomly divided into three groups: G5 (KR every five trials); G3 (KR every three trials) and G100 (KR every trial). The results showed that G3 had a smaller absolute error than G100. However, G3 and G5 had a smaller constant error than G100. In general, the effects of G3 and G5 on motor skill acquisition could be caused by the lower KR frequency, which was 33% and 20% respectively.El efecto del conocimiento de los resultados (KR) resumen ha sido probado por 30 voluntarios en tarea de posicionamiento que requiere el transporte de una pelota de tenis en una secuencia específica con el tiempo objetivo de 3000 ms. en 30 ensayos. Diez minutos después de la fase de adquisición se jugó el test de transferencia con 10 ensayos con diferente secuencia y tempo objetivo. La retención se realizó la prueba 24 horas más tarde con la misma secuencia y tiempo objetivo fase de adquisición. En los testes de transferencia y retención de la CR no fue suministrado. Los voluntarios fueron divididos aleatoriamente en tres grupos: G5 (CR después de 5 ensayos); G3 (CR después de 3 ensayos) y G100 (CR en todos los ensayos). El resultado mostró que G3 tuvieron menor error absoluto que G100. Sin embargo, G3 y G5 se han registrado menor error constante que G100. En general, los efectos de G3 y G5 en la adquisición de las habilidades motoras pueden ser causados por la disminución de frecuencias CR, que fueron 33% y 20 %, respectivamente.O efeito do conhecimento de resultados (CR) sumário foi testado por 30 voluntários em uma tarefa de posicionamento a qual exigia o transporte de uma bola de tênis em uma sequência específica com tempo alvo de 3000 mseg. durante 30 tentativas. Dez minutos após a fase de aquisição foi desempenhado o teste de transferência com 10 tentativas com sequência e tempo alvo diferente. O teste de retenção foi realizado 24 horas mais tarde com a mesma sequência e tempo alvo da fase de aquisição. Nos testes de transferência e retenção o CR não foi fornecido. Os voluntários foram aleatoriamente divididos em três grupos: G5 (CR depois de 5 tentativas); G3 (CR depois de 3 tentativas) e G100 (CR em todas tentativas). O resultado mostrou que G3 apresentou menor erro absoluto que G100. Entretanto, G3 e G5 registraram menor erro constante que G100. Em geral, os efeitos de G3 e G5 sobre a aquisição de habilidades motoras podem ser causados pelas frequências reduzidas de CR, que foram de 33% e 20%, respectivamente
Adherence to Diaphragm Use for Infection Prevention: A Prospective Study of Female Sex Workers in Kenya
Association between Semen Exposure and Incident Bacterial Vaginosis
Objective. To identify correlates of incident bacterial vaginosis (BV) diagnosed with Nugent scoring among high-risk women.
Study Design. We conducted both cohort and case-crossover analyses, stratified by HIV infection status, based on 871 HIV-infected and 439 HIV-uninfected participants in the HIV Epidemiology Research Study, conducted in 4 US sites in 1993–2000. Results. BV incidence was 21% and 19% among HIV-infected and -uninfected women, respectively. Fewer correlates of BV were found with case-crossover than with cohort design. Reporting frequent coitus (regardless of consistency of condom use) was correlated with BV in cohort analyses but not in case-crossover analyses. The sole correlate of BV in both types of analyses was the detection of spermatozoa on Gram stain, which is a marker of semen exposure. Conclusion. The inconsistent association between condom use and BV in prior studies could be from reporting bias. We found evidence of a relationship between semen exposure and incident BV
Childhood behaviour problems predict crime and violence in late adolescence: Brazilian and British birth cohort studies.
PURPOSE: Most children live in low- and middle-income countries (LMICs), many of which have high levels of violence. Research in high-income countries (HICs) shows that childhood behaviour problems are important precursors of crime and violence. Evidence is lacking on whether this is also true in LMICs. This study examines prevalence rates and associations between conduct problems and hyperactivity and crime and violence in Brazil and Britain. METHODS: A comparison was made of birth cohorts in Brazil and Britain, including measures of behaviour problems based on parental report at age 11, and self-reports of crime at age 18 (N = 3,618 Brazil; N = 4,103 Britain). Confounders were measured in the perinatal period and at age 11 in questionnaires completed by the mother and, in Brazil, searches of police records regarding parental crime. RESULTS: Conduct problems, hyperactivity and violent crime were more prevalent in Brazil than in Britain, but nonviolent crime was more prevalent in Britain. Sex differences in prevalence rates were larger where behaviours were less common: larger for conduct problems, hyperactivity, and violent crime in Britain, and larger for nonviolent crime in Brazil. Conduct problems and hyperactivity predicted nonviolent and violent crime similarly in both countries; the effects were partly explained by perinatal health factors and childhood family environments. CONCLUSIONS: Conduct problems and hyperactivity are similar precursors of crime and violence across different social settings. Early crime and violence prevention programmes could target these behavioural difficulties and associated risks in LMICs as well as in HICs.This is the final published version, published by Springer in Social Psychiatry and Psychiatric Epidemiology (http://link.springer.com/article/10.1007%2Fs00127-014-0976-z)
praja2 regulates KSR1 stability and mitogenic signaling
The kinase suppressor of Ras 1 (KSR1) has a fundamental role in mitogenic signaling by scaffolding components of the Ras/MAP kinase pathway. In response to Ras activation, KSR1 assembles a tripartite kinase complex that optimally transfers signals generated at the cell membrane to activate ERK. We describe a novel mechanism of ERK attenuation based on ubiquitin-dependent proteolysis of KSR1. Stimulation of membrane receptors by hormones or growth factors induced KSR1 polyubiquitination, which paralleled a decline of ERK1/2 signaling. We identified praja2 as the E3 ligase that ubiquitylates KSR1. We showed that praja2-dependent regulation of KSR1 is involved in the growth of cancer cells and in the maintenance of undifferentiated pluripotent state in mouse embryonic stem cells. The dynamic interplay between the ubiquitin system and the kinase scaffold of the Ras pathway shapes the activation profile of the mitogenic cascade. By controlling KSR1 levels, praja2 directly affects compartmentalized ERK activities, impacting on physiological events required for cell proliferation and maintenance of embryonic stem cell pluripotency
Inbreeding, native American ancestry and child mortality:Linking human selection and paediatric medicine
The children of related parents show increased risk of early mortality. The Native American genome typically exhibits long stretches of homozygosity, and Latin Americans are highly heterogeneous regarding the individual burden of homozygosity, the proportion and the type of Native American ancestry. We analysed nationwide mortality and genome-wide genotype data from admixed Chileans to investigate the relationship between common causes of child mortality, homozygosity and Native American ancestry. Results from two-stage linear-Poisson regression revealed a strong association between the sum length of runs of homozygosity (SROH) above 1.5 Megabases (Mb) in each genome and mortality due to intracranial non-traumatic haemorrhage of foetus and newborn (5% increased risk of death per Mb in SROH, P = 1 × 10(−3)) and disorders related to short gestation and low birth weight (P = 3 × 10(−4)). The major indigenous populations in Chile are Aymara–Quechua in the north of the country and the Mapuche–Huilliche in the south. The individual proportion of Aymara–Quechua ancestry was associated with an increased risk of death due to anencephaly and similar malformations (P = 4 × 10(−5)), and the risk of death due to Edwards and Patau trisomy syndromes decreased 4% per 1% Aymara–Quechua ancestry proportion (P = 4 × 10(−4)) and 5% per 1% Mapuche–Huilliche ancestry proportion (P = 2 × 10(−3)). The present results suggest that short gestation, low birth weight and intracranial non-traumatic haemorrhage mediate the negative effect of inbreeding on human selection. Independent validation of the identified associations between common causes of child death, homozygosity and fine-scale ancestry proportions may inform paediatric medicine
Vaginal swab specimen processing methods influence performance of rapid semen detection tests: a cautionary tale
Detection of semen biomarkers in vaginal fluid can be used to assess women’s recent exposure to semen. Quantitative tests for detection of prostate-specific antigen (PSA) perform well, but are expensive and require specialized equipment. We assessed two rapid immunochromatographic strip tests for identification of semen in vaginal swabs
Inbreeding, Native American ancestry and child mortality: linking human selection and paediatric medicine
The children of related parents show increased risk of early mortality. The Native American genome typically exhibits long stretches of homozygosity, and Latin Americans are highly heterogeneous regarding the individual burden of homozygosity, the proportion and the type of Native American ancestry. We analysed nationwide mortality and genome-wide genotype data from admixed Chileans to investigate the relationship between common causes of child mortality, homozygosity and Native American ancestry. Results from two-stage linear-Poisson regression revealed a strong association between the sum length of runs of homozygosity (SROH) above 1.5 Megabases (Mb) in each genome and mortality due to intracranial non-traumatic haemorrhage of foetus and newborn (5% increased risk of death per Mb in SROH, P = 1 × 10−3) and disorders related to short gestation and low birth weight (P = 3 × 10−4). The major indigenous populations in Chile are Aymara–Quechua in the north of the country and the Mapuche–Huilliche in the south. The individual proportion of Aymara–Quechua ancestry was associated with an increased risk of death due to anencephaly and similar malformations (P = 4 × 10−5), and the risk of death due to Edwards and Patau trisomy syndromes decreased 4% per 1% Aymara–Quechua ancestry proportion (P = 4 × 10−4) and 5% per 1% Mapuche–Huilliche ancestry proportion (P = 2 × 10−3). The present results suggest that short gestation, low birth weight and intracranial non-traumatic haemorrhage mediate the negative effect of inbreeding on human selection. Independent validation of the identified associations between common causes of child death, homozygosity and fine-scale ancestry proportions may inform paediatric medicine.Fil: Koenigstein, Fabienne. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Boekstegers, Felix. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Wilson, James F.. University of Edinburgh; Reino UnidoFil: Fuentes Guajardo, Macarena. Universidad de Tarapacá; ChileFil: Gonzalez-Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Bedoya Berrío, Gabriel. Universidad de Antioquia; ColombiaFil: Bortolini, Maria Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Acuña Alonzo, Victor. Instituto Nacional de Antropología e Historia. Escuela Nacional de Antropología e Historia; MéxicoFil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerúFil: Ruiz-Linares, Andres. Fudan University; China. Aix-Marseille Université; Francia. Centre National de la Recherche Scientifique; Francia. University College London; Reino UnidoFil: Rothhammer, Francisco. Universidad de Tarapaca. Instituto de Alta Investigación; ChileFil: Lorenzo Bermejo, Justo. Ruprecht Karls Universitat Heidelberg; Alemani
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