Exposure of young rats to high estrogen doses leads to degeneration of elongated spermatids

Single high doses of estrogen (35 mg/kg body weight) were administered to young rats aiming to exacerbate its effects on germ cell populations. The short-term (1 week) and medium-term (7 weeks) consequences of this estrogenic treatment (ET) on the testis were evaluated using light and electron microscopies, quantitative methods and TUNEL reaction. Short-term ET led to 50% atrophy of the testis, however, in the medium term the gonado-somatic index was recovered. No histopathological alterations were found at seminiferous epithelium except for short-term severe degeneration of elongated spermatids (EL) and low frequency of these cells in both time intervals. Two morphologically distinct patterns of degeneration were observed: (1) clusters of EL which were TUNEL-negative and exhibited bizarre appearance and nuclear fragmentation, (2) isolated apoptotic EL within the cytoplasm of Sertoli cells (SC). Both degenerative phenomena were more frequent in stages III - VIII of seminiferous cycle, whereas at stages I and II only coiling of flagellum was observed. One week after ET, small amounts of EL were detected in stages IX - XII, suggesting spermiation failure. Signs of functional SC damage such as an accumulation of myelin-like inclusions in their cytoplasm were observed in the short but not medium-term. However, the apoptotic rates still remained five times higher and the number of elongated spermatids was three-fold lower. Our data indicate that exposure to a high dose of estrogen around puberty has stage-specific effects on the testis and causes massive degeneration of elongated spermatids. (c) 2007 Elsevier Ltd. All rights reserved.

Microscopic comparative study of the exposure effects of testosterone cypionate and ethinylestradiol during prenatal life on the prostatic tissue of adult gerbils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estrogênios em águas naturais e tratadas da região de Jaboticabal - São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos tardios dos praguicidas organoclorados no homem

Procurou-se relacionar as informações disponíveis sobre os organoclorados e os efeitos crônicos provocados pela exposição. Os compostos organoclorados são os praguicidas mais persistentes já fabricados. Embora sejam geralmente eficientes no controle das pragas, são importantes poluentes ambientais e potenciais causas de problemas de saúde para o homem, tendo sido proibidos ou controlados na maioria dos países. Com poucas exceções, os efeitos tardios desses compostos sobre a saúde humana são difíceis de detectar, em função de dificuldades metodológicas e da extrapolação dos resultados. A genotoxicidade está entre os mais sérios dos possíveis danos causados por esses compostos e merece atenção especial, devido à natureza irreversível do processo. Outro ponto a ser considerado é o aumento na incidência de alterações no desenvolvimento do trato reprodutivo e na fertilidade masculina observada nas últimas décadas provavelmente decorrente do aumento da exposição intra-uterina a compostos estrogênicos e anti-androgênicos, como os organoclorados.

Quadro citológico vaginal, concentração plasmática de progesterona durante a gestação e medidas fetais em paca (Cuniculus paca Linnaeus, 1766)

Em 27 pacas (Cuniculus paca Linnaeus, 1766) objetivou-se descrever aos 30, 60 e 90 dias (D) de prenhez diagnosticada por ultrassonografia (US), os tipos celulares do epitélio vaginal em esfregaços vaginais, relatar as condições de abertura da vulva e as características do muco vaginal, determinar a concentração plasmática de progesterona (P4) por radioimunoensaio, e ainda, mensurar por ultrassonografia (US) o diâmetro biparietal (DBP) fetal aos 60 e 90 dias de prenhez. No D30, 40% das amostras exibiram células (com características estrogênicas) superficiais e presença de núcleos nus. Nos D60 e D90, células parabasais, intermediárias, superficiais e naviculares estavam presentes nas mesmas proporções, mas células endocervicais foram descritas em apenas 73,9% e 69% das amostras daqueles dias, respectivamente. No D30 a maior proporção de células naviculares e superficiais diferiu (p < 0,05) em relação aos outros tipos celulares presentes. O muco vaginal apresentou-se cristalino e fluido em 100% e em 70% das fêmeas nos D30 e D60, respectivamente. Observou-se o vestíbulo vaginal aberto em torno de 50% das fêmeas em todos os dias de exames. Valores mínimos detectáveis de P4 foram obtidos em 72% e em 83% das fêmeas, enquanto que as médias das medidas dos DBP foram 1,25 cm (± 0,16) e 2,34 cm (± 0,25) nos D60 e D90, respectivamente. O quadro citológico vaginal nos D30, D60 e D90 e o DBP fornecem elementos que contribuem para diagnóstico de gestação em pacas. A concentração de P4 demonstra a necessidade de maiores estudos da endocrinologia da gestação em pacas.

Occurrence of killer yeasts in leaf-cutting ant nests

Killer activity was screened in 99 yeast strains isolated from the nests of the leaf-cutting ant Atta sexdens against 6 standard sensitive strains, as well as against each other. Among this yeast community killer activity was widespread since 77 strains (78 %) were able to kill or inhibit the growth of at least one standard strain or nest strain. Toxin production was observed in representatives of all the studied genera including Aureobasidium, Rhodotorula, Tremella and Trichosporon, whose killer activity has not yet been described.

Síndrome do climatério

The climateric is characterized by progressive hipoestrogenism and by tissue and functional alterations that leads the women to aging. The diagnosis approach needs to consider the symptoms originated by estrogenic deficiency and by the more prevalent chronic diseases in this lifetime, for instance, among others, the cardiovascular and osteoporosis diseases, witch need a systematic screening. The therapeutic management must consider the proposition of healthy life habits and, when indicated, pharmacological treatment for estrogenic deficiency or for anothers comorbidities existent. The estroprogestative hormonal therapeutic is a valuable tool to provide health and better quality of life, once obeyed the individualized criterion of the cases, doses, hormonal composition and mainly of the opportunity of intervention. There are nonhormonal alternatives to treat the menopausal symptoms, as the antidepressives and phytoestrogens. It's also advised to combine with regular physical activities and adequate calcium intake. © Copyright Moreira Jr. Editora. Todos os direitos reservados.

New destruxins from the marine-derived fungus Beauveria felina

Chemical investigation of the cytotoxic and anti-tuberculosis active butanone extract obtained from the growth media of the marine-derived fungus Beauveria felina led to the isolation of two new destruxins, [β-MePro] destruxin E chlorohydrin (1) and pseudodestruxin C (3), along with five known cyclic depsipeptides. The structures of the new destruxin derivatives were established by analysis of spectroscopic data, while the absolute configuration of the common amino acid residues was established by Marfey's analysis. The absolute configuration of the 2(A),4(5)-5-chloro-2,4-dihydroxypentanoic acid residue in 1 could be established by application of a J-based configuration method followed by derivatization with R-MPA-Cl and NMR analysis. © Japan Antibiotics Research Association.

Evaluation of urban ants (hymenoptera: formicidae) as vectors of microorganisms in residential and industrial environments: II. Fungi

Collections in households and industrial kitchens were done aiming at evaluating the potential of urban ants in spreading fungi. The most abundant ant species in households were Tapinoma melanocephalum and Paratrechina longicornis. In industrial kitchens Paratrechina longicornis and Monomorium floricola were the most common. Tapinoma melanocephalum was the species that most carried fungi, followed by Paratrechina longicornis, Tetramorium sp., Monomorium pharaonis and Monomorium floricola. An aflatoxigenic strain of Aspergillus flavus was isolated.

Synthesis, characterization and antifungal activity of quaternary derivatives of chitosan on Aspergillus flavus

Two series of new chitosan derivatives were synthesized by reaction of deacetylated chitosan (CH) with propyl (CH-Propyl) and pentyl (CH-Pentyl) trimethylammonium bromides to obtain derivatives with increasing degrees of substitution (DS). The derivatives were characterized by 1H NMR and potentiometric titration techniques and their antifungal activities on the mycelial growth of Aspergillus flavus were investigated in vitro. The antifungal activities increase with DS and the more substituted derivatives of both series, CH-Propyl and CH-Pentyl, exhibited antifungal activities respectively three and six times higher than those obtained with commercial and deacetylated chitosan. The minimum inhibitory concentrations (MIC) were evaluated at 24, 48 and 72h by varying the polymer concentration from 0.5 to 16g/L and the results showed that the quaternary derivatives inhibited the fungus growth at polymer concentrations four times lower than that obtained with deacetylated chitosan (CH). The chitosans modified with pentyltrimethylammonium bromide exhibited higher activity and results are discussed taking into account the degree of substitution (DS). © 2012 Elsevier GmbH.

Lipid metabolism of commercial layers fed diets containing aflatoxin, fumonisin, and a binder

Aflatoxins (AF) and fumonisins (FU) are a major problem faced by poultry farmers, leading to huge economic losses. This experiment was conducted to determine the effects of AF (1 mg/kg of feed) and FU (25 mg/kg of feed), singly or in combination, on the lipid metabolism in commercial layers and investigate the efficacy of a commercial binder (2 kg/t of feed) on reducing the toxic effects of these mycotoxins. A total of 168 Hisex Brown layer hens, 37 wk of age, were randomized into a 3 × 2 + 1 factorial arrangement (3 diets with no binder containing AF, FU, and AF+FU; 3 diets with binder containing AF, FU, and AF+FU; and a control diet with no mycotoxins and binders), totaling 7 treatments. The hens contaminated with AF showed the characteristic effects of aflatoxicosis, such as a yellow liver, resulting from the accumulation of liver fat, lower values of plasma very low-density lipoprotein and triglycerides, and higher relative weight of the kidneys and liver. Hepatotoxic and nephrotoxic effects of FU were not observed in this study. On the other hand, the FU caused a reduction in small intestine length and an increase in abdominal fat deposition. The glucan-based binder prevented some of the deleterious effects of these mycotoxins, particularly the effects of AF on hepatic lipid metabolism, kidney relative weight, and FU in the small intestine. © 2013 Poultry Science Association Inc.

Avaliação da toxicidade e caracterização de hidrocarbonetos presentes em águas de rios que recebem efluente de indústria petroquímica

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Avaliação in vitro da melatonina como agente terapêutico em tumores mamários estrógeno-dependentes ou não

Pós-graduação em Genética - IBILCE

Avaliação da mutagenicidade, antimutagenicidade e estrogenicidade de Byrsonima spp

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mutagenicidade e estrogenicidade de plantas da família Eriocaulaceae e relação estrutura-atividade de algumas substâncias isoladas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)