232 research outputs found

    The testosterone metabolism of <i>Neomysis integer</i>: the quest continues… (poster)

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    Both vertebrate and invertebrate species use enzymatic biotransformations for detoxication and elimination of xenobiotics. Testosterone has been used as a substrate to study the multiplicity of these enzymes. Since many of these enzymes are under hormone control, disruption of the hormone function can lead to potential effects on enzyme function and subsequently steroid homeostasis. The testosterone metabolism has therefore been proposed as a biomarker of exposure to endocrine disruptive compounds.In a previous study, the estuarine crustacean Neomysis integer (Crustacea, Mysidacea) was exposed to both testosterone and [14C]-testosterone. Identification and quantification of testosterone metabolites and endogenous steroids was done using TLC and LC-MSn (Verslycke et al., Gen. Comp. Endocrinol., accepted). The use of liquid chromatography coupled with multiple mass spectrometry allows a unique quantification of both endogenously produced steroids and in vivo produced metabolites in single mysid. Recent research has focused on the potential use of these biotransformations as a predictive biomarker for exposure to known endocrine disruptors. In this context, quantitative changes in the biotransformation profile of testosterone were evaluated after exposure to tributyltin (TBT), a compound used in antifouling paint, which has been suspected to interfere with steroid metabolism. The resulting protocol allows a quantitative and qualitative evaluation of the effect of TBT on the testosterone metabolism of N. integer. The results of these exposures will be presented and a possible mechanism of disruption through interaction with the P450 enzyme system is proposed.Future research on the steroid metabolism of N. integer could result in the development of predictive biomarkers for detection of endocrine disruption in estuarine environments

    Adjuvant high-dose medroxyprogesterone acetate for early breast cancer: 13 years update in a multicentre randomized trial

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    The authors updated their report on a randomized trial initiated in 1982 comparing, in early breast cancer, high-dose IM Medroxyprogesterone acetate (HD-MPA) adjuvant hormonotherapy during 6 months with no hormonotherapy; node-positive patients also received 6 courses of IV CMF (day 1, day 8; q.4 weeks). 246 node-negative (NN) and 270 node-positive (NP) patients had been followed for a median duration of 13 years. Previous results were confirmed in this analysis on mature data. In NN patients, relapse-free survival (RFS) was improved in the adjuvant hormonotherapy arm, regardless of age while overall survival (OAS) was also increased in younger (less then 50 years) patients. In the whole group of NP patients, no difference was seen regarding RFS or OAS. However, an age-dependant opposite effect was observed: younger patients (< 50) experienced a worse and significant outcome of relapse-free and overall survivals when receiving adjuvant HD-MPA while older patients (> = 50) enjoyed a significant improvement of their relapse-free survival. For both NN and NP patients, differences in overall survivals observed in older women with a shorter follow-up, were no longer detected. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Uso referido de suplementos alimentares por corredores de montanha

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    Corredores de montanha possuem uma necessidade aumentada de ingesta calórica, durante a corrida, fato que faz com que os atletas optem pela utilização de suplementação, no momento de repor a energia perdida. A presente investigação teve por objetivo determinar o suplemento mais utilizado por corredores de montanha. A amostra foi constituída por 97 atletas Brasileiros corredores de montanha de ambos os sexos. Os homens apresentaram idade média de 41,3±10,2 anos e as mulheres 39,3±8,6 anos. Os dados foram levantados por meio de um questionário composto por 34 questões fechadas, e as respostas apresentadas no formato de média, desvio padrão, amplitude. Empregou-se uso de frequências absoluta e relativa e teste qui-quadrado para testar diferentes proporções nas respostas emitidas, assumiu-se 5% como nível de significância. Os resultados mostraram que os suplementos mais utilizados pelos corredores de montanha do sexo masculino foram às proteínas 38,1%, seguido por carboidratos e isotônicos 36,1%. As mulheres reportaram predileção por proteínas 20,6% seguido pelos isotônicos 21,6% e Aminoácidos de Cadeia Ramificada (BCAA)15,5%. Sobre os motivos da utilização de suplementos 16,5% dos homens tinha por objetivo suprir deficiência alimentares, 34,2% melhora do desempenho, 17,5% aumento da força e massa muscular. Em se tratando dos indivíduos que incentivaram o consumo da suplementação, 33% e 22.7% dos homens e mulheres tiveram inventivo de um nutricionista. Pode-se concluir que os Corredores de Montanha da presente pesquisa, fazem uso de suplementos alimentares onde os mesmos são prescritos em sua maioria por um profissional de Nutrição. ABSTRACT Referred use of alimentary supplement for mountain runnersMountain runners have an increased need for caloric intake during the running, a fact that leads the athletes to choose to use supplementation when they need to catch their energy. This study aimed to find out the supplement most used by mountain runners. The sample consisted of 97 Brazilian mountain runners male and female. Males presented a mean age of 41.3 ± 10.2 years old and women 39.3 ± 8.6 years old. The data were collected through a questionnaire composed of 34 closed questions, and the answers presented in the format of mean, standard deviation, and amplitude. Absolute and relative frequencies were used and chi-square test to verify different proportions in the answers was also required, assuming 5% as a level of significance. The results showed that supplements most commonly used by male mountain runners were protein at 38.1% followed by carbohydrate and isotonic 36.1%. Women reported a preference for proteins 20.6% followed by isotonic 36.1% and Branched Chain Amino (BCAAs) 15.5%. Regarding the reasons for use of supplements 16.5% of men had as objective to supply food deficiency, 34.2% improved performance, and 17,5% increase strength and muscle mass. Concerning the people who encouraged the consumption of supplementation, 33% of men and 22,7% of woman had inventiveness of a nutritionist. In conclusion, it is possible to suggest that mountain runners make use of supplements and that they are prescribed by nutritionists

    Testosterone metabolism in Neomysis integer following exposure to benzo(a)pyrene

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    Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 144 (2006): 405-412, doi:10.1016/j.cbpb.2006.04.001.Cytochromes P450 (CYPs) are important enzymes involved in the regulation of hormone synthesis and in the detoxification and/or activation of xenobiotics. CYPs are found in virtually all organisms, from archae, and eubacteria to eukaryota. A number of endocrine disruptors are suspected of exerting their effects through disruption of normal CYP function. Consequently, alterations in steroid hormone metabolism through changes in CYP could provide an important tool to evaluate potential effects of endocrine disruptors. The aim of this study was to investigate the potential effects of the known CYP modulator, benzo(a)pyrene (B(a)P), on the testosterone metabolism in the invertebrate Neomysis integer (Crustacea; Mysidacea). N. integer were exposed for 96h to 0.43, 2.39, 28.83, 339.00 and 1682.86μg B(a)P L-1 and a solventcontrol, and subsequently their ability to metabolize testosterone was assessed. Identification and quantification of the produced phase I and phase II testosterone metabolites was performed using liquid chromatography coupled with multiple mass spectrometry (LC-MS2). Significant changes were observed in the overall ability of N. integer to metabolize testosterone when exposed to 2.39, 28.83, 339.00 and 1682.86μg B(a)P L-1 as compared to the control animals.This research was supported by a research grant of the Ghent University Research Fund (BOF, 011.072.02). Dr. Tim Verslycke was supported by a Postdoctoral Fellowship of the Belgian American Educational Foundation

    TSPY potentiates cell proliferation and tumorigenesis by promoting cell cycle progression in HeLa and NIH3T3 cells

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    BACKGROUND: TSPY is a repeated gene mapped to the critical region harboring the gonadoblastoma locus on the Y chromosome (GBY), the only oncogenic locus on this male-specific chromosome. Elevated levels of TSPY have been observed in gonadoblastoma specimens and a variety of other tumor tissues, including testicular germ cell tumors, prostate cancer, melanoma, and liver cancer. TSPY contains a SET/NAP domain that is present in a family of cyclin B and/or histone binding proteins represented by the oncoprotein SET and the nucleosome assembly protein 1 (NAP1), involved in cell cycle regulation and replication. METHODS: To determine a possible cellular function for TSPY, we manipulated the TSPY expression in HeLa and NIH3T3 cells using the Tet-off system. Cell proliferation, colony formation assays and tumor growth in nude mice were utilized to determine the TSPY effects on cell growth and tumorigenesis. Cell cycle analysis and cell synchronization techniques were used to determine cell cycle profiles. Microarray and RT-PCR were used to investigate gene expression in TSPY expressing cells. RESULTS: Our findings suggest that TSPY expression increases cell proliferation in vitro and tumorigenesis in vivo. Ectopic expression of TSPY results in a smaller population of the host cells in the G(2)/M phase of the cell cycle. Using cell synchronization techniques, we show that TSPY is capable of mediating a rapid transition of the cells through the G(2)/M phase. Microarray analysis demonstrates that numerous genes involved in the cell cycle and apoptosis are affected by TSPY expression in the HeLa cells. CONCLUSION: These data, taken together, have provided important insights on the probable functions of TSPY in cell cycle progression, cell proliferation, and tumorigenesis

    Co-expression network of neural-differentiation genes shows specific pattern in schizophrenia

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    Background: Schizophrenia is a neurodevelopmental disorder with genetic and environmental factors contributing to its pathogenesis, although the mechanism is unknown due to the difficulties in accessing diseased tissue during human neurodevelopment. The aim of this study was to find neuronal differentiation genes disrupted in schizophrenia and to evaluate those genes in post-mortem brain tissues from schizophrenia cases and controls. Methods: We analyzed differentially expressed genes (DEG), copy number variation (CNV) and differential methylation in human induced pluripotent stem cells (hiPSC) derived from fibroblasts from one control and one schizophrenia patient and further differentiated into neuron (NPC). Expression of the DEG were analyzed with microarrays of post-mortem brain tissue (frontal cortex) cohort of 29 schizophrenia cases and 30 controls. A Weighted Gene Co-expression Network Analysis (WGCNA) using the DEG was used to detect clusters of co-expressed genes that werenon-conserved between adult cases and controls brain samples. Results: We identified methylation alterations potentially involved with neuronal differentiation in schizophrenia, which displayed an over-representation of genes related to chromatin remodeling complex (adjP = 0.04). We found 228 DEG associated with neuronal differentiation. These genes were involved with metabolic processes, signal transduction, nervous system development, regulation of neurogenesis and neuronal differentiation. Between adult brain samples from cases and controls there were 233 DEG, with only four genes overlapping with the 228 DEG, probably because we compared single cell to tissue bulks and more importantly, the cells were at different stages of development. The comparison of the co-expressed network of the 228 genes in adult brain samples between cases and controls revealed a less conserved module enriched for genes associated with oxidative stress and negative regulation of cell differentiation. Conclusion: This study supports the relevance of using cellular approaches to dissect molecular aspects of neurogenesis with impact in the schizophrenic brain. We showed that, although generated by different approaches, both sets of DEG associated to schizophrenia were involved with neocortical development. The results add to the hypothesis that critical metabolic changes may be occurring during early neurodevelopment influencing faulty development of the brain and potentially contributing to further vulnerability to the illness.We thank the patients, doctors and nurses involved with sample collection and the Stanley Medical Research Institute. This research was supported by either Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq #17/2008) and Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ). MM (CNPq 304429/2014-7), ACT (FAPESP 2014/00041-1), LL (CAPES 10682/13-9) HV (CAPES) and BP (PPSUS 137270) were supported by their fellowshipsinfo:eu-repo/semantics/publishedVersio
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