Amaç: Bu çalışmanın amacı neonatal dönem Bisfenol A (BPA) uygulanmasına karşı melatoninin rat ovaryumları üzerindeki etkisinin araştırılmasıdır.Gereç ve Yöntemler: Bu çalışmada Wistar Albino cinsi, ...24 adet, yenidoğan dişi rat 4 gruba ayrılmıştır (n=6). Kontrol ve BPA grubu ratlara, sırasıyla, susam yağı + etanol ve BPA (100 mg/kg) postnatal 10 gün boyunca (PNG0-PNG10) subkutan olarak enjekte edilmiştir. Melatonin grubu ratlara günlük (10 mg/kg) melatonin (PNG20-PNG30) ve BPA+melatonin grubu ratlara ise günlük (100 mg/kg) BPA (PNG0-PNG10) ve (10 mg/kg) melatonin (PNG20-PNG30) 10 gün boyunca, subkutan olarak enjekte edilmiştir. Histolojik ve morfolojik analizler yapılarak ovaryum dokuları incelenmiştir. Bunlara ek olarak oosit hücre siklusu marker CDC-2 immunohistokimyal yöntem kullanılarak tespit edilmiştir.Bulgular: Histolojik bulgular neonatal dönemde BPA maruziyetinin ovaryumda dejeneratif değişikliklere neden olduğunu göstermiştir. Morfolojik analizler sonucunda, vücut ağırlık artışları ve ovaryum dokusu ağırlıkları gruplar arasında istatistiksel olarak anlamlı bir fark saptanmazken BPA grubunda diğer gruplara kıyasla kilo alımının ve ovaryum dokusu ağırlığının daha fazla olduğu saptanmıştır. Bunlara ek olarak, immunohistokimyasal bulgularımızda, Cdc-2 immunreaktivitesinin BPA grubu ratlarda diğer gruplarla karşılaştırıldığında daha düşük olduğu saptanmıştır.Sonuç: Neonatal dönemde BPA maruziyetinin folikülogeneze zarar verdiği, bu durumun da ovarium foliküllerinde dejeneratif değişikliklere neden olduğu ve melatonin de BPA tarafından hasar verilen rat ovaryumları üzerinde pozitif etkisi olabileceği kanısına varılmıştır.
Prenatal exposure to bisphenol A (BPA) and phthalates may affect fetal growth; however, previous findings are inconsistent and based on few studies.
We assessed whether prenatal exposure to BPA and ...phthalates was associated with fetal growth in a Spanish birth cohort of 488 mother-child pairs.
We measured BPA and eight phthalates four di(2-ethylhexyl) phthalate metabolites (DEHPm), mono-benzyl phthalate (MBzP), and three low-molecular-weight phthalate metabolites (LMWPm) in two spot-urine samples collected during the first and third trimester of pregnancy. We estimated growth curves for femur length (FL), head circumference (HC), abdominal circumference (AC), biparietal diameter (BPD), and estimated fetal weight (EFW) during pregnancy (weeks 12-20 and 20-34), and for birth weight, birth length, head circumference at birth, and placental weight.
Overall, results did not support associations of exposure to BPA or DEHPm during pregnancy with fetal growth parameters. Prenatal MBzP exposure was positively associated with FL at 20-34 weeks, resulting in an increase of 3.70% of the average FL (95% CI: 0.75, 6.63%) per doubling of MBzP concentration. MBzP was positively associated with birth weight among boys (48 g; 95% CI: 6, 90) but not in girls (-27 g; 95% CI: -79, 25) (interaction p-value = 0.04). The LMWPm mono-n-butyl phthalate (MnBP) was negatively associated with HC at 12-20 pregnancy weeks -4.88% of HC average (95% CI: -8.36, -1.36%).
This study, one of the first to combine repeat exposure biomarker measurements and multiple growth measures during pregnancy, finds little evidence of associations of BPA or phthalate exposures with fetal growth. Phthalate metabolites MBzP and MnBP were associated with some fetal growth parameters, but these findings require replication.
Casas M, Valvi D, Ballesteros-Gomez A, Gascon M, Fernández MF, Garcia-Esteban R, Iñiguez C, Martínez D, Murcia M, Monfort N, Luque N, Rubio S, Ventura R, Sunyer J, Vrijheid M. 2016. Exposure to bisphenol A and phthalates during pregnancy and ultrasound measures of fetal growth in the INMA-Sabadell cohort. Environ Health Perspect 124:521-528; http://dx.doi.org/10.1289/ehp.1409190.
Performance of Steel Fibers in Polymer Concrete Nayak, Aditya; Babu, S. Vinay; Ramana, Dr. N. Venkata
International journal of innovative technology and exploring engineering,
10/2019, Volume:
8, Issue:
12
Journal Article
Open access
This article presents the effect of fibers in the polymer concrete. The concrete was designed with M25 grade concrete and 10% of Bisfenol –A was added to produce polymer concrete. Few mixes are ...planned with incorporation of steel fibers in the proportion of 1 and 2% by volume. In all the mixes manufacture sand was used instead of river sand. The tests are conducted to estimate compressive, split and flexural strengths. From the results it is noticed that, the strengths are increasing with incorporation of polymer and steel fibers.
Objectives: We aimed to evaluate the effects of chronic exposure to bisphenol A (BPA) on atrial fibrillation (AF) occurrence in rats. Methods: Twenty-two healthy female Wistar rats were randomized ...into three groups: Control (no BPA; n=7), BPA (exposed to usual BPA doses; 50 μg/kg/day, 9 weeks; n=7), and hBPA (exposed to high BPA doses; 25 mg/kg/day, 9 weeks; n=8). 24-h ECG monitoring was performed using radiotelemetry ECG devices prior to and after transesophageal atrial pacing. Spontaneous and pacing-induced atrial arrhythmias, autonomic tone, and in vivo an in vitro atrial arrhythmogenicity-related parameters were evaluated. Results: All studied parameters were similar between Control and BPA (all p>0.05). However, compared to Control, hBPA presented more atrial premature beats both at baseline (p=0.04) and after pacing (p=0.03), more AF episodes (p<0.001) and of longer duration (p=0.02) following transesophageal stimulation, and significantly higher vagal tone (all p<0.05). Conclusions: Chronic exposure to high, but not usual BPA doses induced significant atrial proarrhythmic effects in healthy rats, and this may be at least partially due to BPA-induced vagal hyperactivation. Exposure to high BPA doses, such as that occurring in plastics industry workers, could favor AF occurrence even in the absence of underlying cardiovascular disease.
Introducción: El bisfenol A (BPA) es un contaminante químico no persistente que altera el funcionamiento normal del sistema endocrino. Se sugiere que la exposición prenatal se asocia con la obesidad ...en la descendencia. Objetivo: Revisar la literatura sobre la exposición al BPA en mujeres embarazadas y su relación con la obesidad en sus hijos. Metodología: Revisión sistemática de acuerdo a la guía PRISMA. Se realizaron búsquedas en las bases de datos Pubmed, ScienceDirect, Clinical Key, Medline, Ebsco y Scielo y el motor de búsqueda Google Scholar hasta el 30 de Abril de 2017 por dos investigadores independientes que utilizaron los mismos términos de búsqueda. Se incluyeron estudios prospectivos de cohorte realizados que midieron el BPA en la orina materna. Resultados: Se incluyeron 5 estudios con tamaños de muestra entre 297 y 757 binomios madre e hijo, se encontró asociación positiva entre la exposición prenatal a BPA con la circunferencia de cintura en niños de cuatro años beta: 0.28 (IC95%:0.01 a 0.57) y el índice de masa grasa beta: 0.31 (IC95%: 0.01 a 0.60) en dos de los estudios. Se observaron asociaciones positivas y/o negativas no significativas con índice de masa corporal y su puntaje Z, porcentaje de grasa, sobrepeso/obesidad, peso y talla al nacer, porcentaje de masa grasa. Conclusión: Los resultados de estudios epidemiológicos de cohorte, limita las afirmaciones sobre un vínculo causal entre la exposición prenatal BPA y la obesidad postnatal.
Muchas toxinas urémicas son originadas como consecuencia del catabolismo proteico por la flora intestinal. El metabolismo de aminoácidos aromáticos origina residuos de tipo fenólico. De estas ...toxinas, la más estudiada es el p-cresol, que se asocia a la función renal y daño vascular. El Bisfenol A (BPA) es una molécula exógena de características semejantes a estas toxinas urémicas aromáticas. El BPA es un disruptor endocrino estrogénico que se encuentra en latas de conserva, botellas de plástico, resinas epoxi y en algunos dializadores. Esta molécula se acumula en pacientes que tienen deteriorada la función renal. Estudios observacionales han demostrado que una exposición a BPA está vinculada, entre otras muchas, a lesión renal y cardiovascular en los seres humanos; en estudios en animales se ha descrito un vínculo causal. Los riñones con función renal normal excretan rápidamente BPA, pero una excreción insuficiente en pacientes con ERC da lugar a la acumulación del BPA en el organismo.
Bisfenol A (BPA) e um dos produtos quimicos mais produzido em todo o mundo, e a exposicao humana a ele e considerada onipresente. Assim, ha preocupacoes de que a quantidade de BPA para o qual os ...seres humanos estao expostos podem causar efeitos adversos a saude. Nos examinamos muitas possibilidades sobre o porque estudos de biomonitorizacao e toxicocinetica podem chegar a conclusoes aparentemente conflitantes. Mais de 80 estudos publicados de biomonitorizacao humana que mediram a concentracao de BPA em tecidos humanos, urina, sangue e outros fluidos, juntamente com dois estudos de toxicocinetica do metabolismo humano BPA foram examinados. BPA nao conjugado foi detectado no sangue (nonanogramas por mililitro gama), e BPA conjugado foi detectado na grande maioria das amostras de urina. Em contraste, estudos de toxico-cinetica propuseram que os seres humanos nao sao internamente expostos ao BPA. Dados disponiveis de estudos de biomonitorizacao indicam que a populacao em geral esta exposta ao BPA e em risco de exposicao interna ao BPA nao conjugado. Os dois estudos de toxicocinetica, que sugeriram a exposicao humana ao BPA e insignificante, tem deficiencias significativas e estao diretamente refutados por outros estudos e, portanto nao sao confiaveis para fins de avaliacao de risco.
Abstract Background and objectives In 2010, wind energy coverage in Spain increased by 16%, making the country the world's fourth largest producer in a fast-developing industry that is also a source ...of employment. Occupational skin diseases in this field have received little attention. The present study aims to describe the main characteristics of skin diseases affecting workers in the wind energy industry and the allergens involved. Material and methods We performed a descriptive, observational study of workers from the wind energy industry with suspected contact dermatitis who were referred to the occupational dermatology clinic of the National School of Occupational Medicine (Escuela Nacional de Medicina del Trabajo) between 2009 and 2011. We took both a clinical history and an occupational history, and patients underwent a physical examination and patch testing with the materials used in their work. Results We studied 10 workers (8 men, 2 women), with a mean age of 33.7 years. The main finding was dermatitis, which affected the face, eyelids, forearms, and hands. Sensitization to epoxy resins was detected in 4 workers, 1 of whom was also sensitized to epoxy curing agents. One worker was sensitized to bisphenol F resin but had a negative result with epoxy resin from the standard series. In the 5 remaining cases, the final diagnosis was irritant contact dermatitis due to fiberglass. Conclusions Occupational skin diseases are increasingly common in the wind energy industry. The main allergens are epoxy resins. Fiberglass tends to produce irritation.
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