Publications by authors named "Michelon J"

Objective: Ectopic pregnancy is a well-known complication following in vitro fertilization with embryo transfer; studies have questioned, however, whether there are risk factors that could be identified before the procedure. The objective of this study was to investigate the possible risk factors involved in ectopic pregnancy following in vitro fertilization.

Methods: Retrospective case-control study performed at an assisted reproduction clinic in Brazil.

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The pathogenesis of endometriosis is not clear; however, microRNAs (miRNAs/miRs) are involved in the pathogenesis. miRNAs are short noncoding RNAs involved in post-transcriptional regulation of gene expression by silencing the expression of target genes. The expression of is associated with endometrial receptivity and implantation; the expression is also associated with the expression of certain genes, including homeobox protein Hox-A10 (.

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Bilateral ectopic pregnancy is a rare clinical condition with an estimated prevalence of 1/200 000 in spontaneous pregnancies. Studies have found that In Vitro Fertilization (IVF) is related to ectopic pregnancy independently, but the incidence of tubal disease in the donor egg recipient population is thought to be significantly lower than in the standard IVF population. We report the case of a patient participating in the egg-sharing program, who was diagnosed with ovarian ectopic pregnancy, treated with surgery.

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Gene expression microarray and next generation sequencing efforts on conventional, clear cell renal cell carcinoma (ccRCC) have been mostly performed in North American and Western European populations, while the highest incidence rates are found in Central/Eastern Europe. We conducted whole-genome expression profiling on 101 pairs of ccRCC tumours and adjacent non-tumour renal tissue from Czech patients recruited within the "K2 Study", using the Illumina HumanHT-12 v4 Expression BeadChips to explore the molecular variations underlying the biological and clinical heterogeneity of this cancer. Differential expression analysis identified 1650 significant probes (fold change ≥2 and false discovery rate <0.

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Background: The gene CHEK2 encodes a checkpoint kinase playing a key role in the DNA damage pathway. Though CHEK2 has been identified as an intermediate breast cancer susceptibility gene, only a small proportion of high-risk families have been explained by genetic variants located in its coding region. Alteration in gene expression regulation provides a potential mechanism for generating disease susceptibility.

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Human embryo cryopreservation techniques enable the storage of surplus embryos created during assisted reproduction procedures; however, the existence of these same surplus embryos has sparked further debate. What can be their fate once they are no longer desired by their parents or if the parents are deceased? Thus, the level of interest in the cryopreservation of oocytes has increased, as has the necessity for further scientific study. This study had the objective of reporting 10 years of experience of freezing and thawing human oocytes from patients who did not wish to freeze embryos.

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NBS1 forms a complex with MRE11 and RAD50 (MRN) that is proposed to act on the upstream of two repair pathways of DNA double-strand break (DSB), homologous repair (HR) and non-homologous end joining (NHEJ). However, the function of Nbs1 in these processes has not fully been elucidated in mammals due to the lethal phenotype of cells and mice lacking Nbs1. Here, we have constructed mouse Nbs1-null embryonic fibroblasts and embryonic stem cells, through the Cre-loxP and sequential gene targeting techniques.

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Human embryo cryopreservation techniques allow storage of surplus embryos created during assisted reproduction procedures; however, the existence of these same surplus embryos has sparked further debate. What can be their fate once they are no longer desired by their parents, or if the parents are deceased? Thus, the level of interest in the cryopreservation of oocytes has increased, as has the necessity for further scientific study. This study had the objective of comparing embryo quality from 16 women who underwent intracytoplasmic sperm injection, where approximately half of the retrieved oocytes per cycle were inseminated fresh after collection, and the remainder cryopreserved for subsequent fertilization.

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A couple (female 31, male 42 years old) with infertility due to obstructive azoospermy returned to the clinic in order to attempt pregnancy using their frozen oocytes and epididymal sperm cells, which had been cryopreserved at the time of a previous IVF attempt. Two days before the scheduled transfer, eight oocytes were thawed; 5/8 (63%) oocytes survived and 4/5 (80%) oocytes fertilized after intracytoplasmic sperm injection (ICSI) with the previously frozen epididymal spermatozoa. All four fertilized ova cleaved (100%).

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Fanconi anemia (FA) cells exhibit hypersensitivity to DNA interstrand cross-links (ICLs) and high levels of chromosome instability. FA gene products have been shown to functionally or physically interact with BRCA1, RAD51 and the MRE11/RAD50/NBS1 complex, suggesting that the FA complex may be involved in the repair of DNA double-strand breaks (DSBs). Here, we have investigated specifically the function of the FA group A protein (FANCA) in the repair of DSBs in mammalian cells.

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Dok1 is an abundant Ras-GTPase-activating protein-associated tyrosine kinase substrate that negatively regulates cell growth and promotes migration. We now find that IkappaB kinase beta (IKKbeta) associated with and phosphorylated Dok1 in human epithelial cells and B lymphocytes. IKKbeta phosphorylation of Dok1 depended on Dok1 S(439), S(443), S(446), and S(450).

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B-cell chronic lymphocytic leukemia (B-CLL) is a malignant disease characterized by an accumulation of monoclonal CD5+ mature B cells, with a high percentage of cells arrested in the G0/G1 phase of the cell cycle, and a particular resistance toward apoptosis-inducing agents. Dok1 (downstream of tyrosine kinases) is an abundant Ras-GTPase-activating protein (Ras-GAP)-associated tyrosine kinase substrate, which negatively regulates cell proliferation, downregulates MAP kinase activation and promotes cell migration. The gene encoding Dok1 maps to human chromosome 2p13, a region previously found to be rearranged in B-CLL.

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Background: Hyperestrogenic conditions have been related to alterations in the coagulation parameters. The objective of this study was to identify changes in coagulation parameters in women undergoing in vitro fertilization and embryo transfer (IVF-ET).

Methods: A group of 15 patients was studied prospectively, immediately before and during the course of an IVF-ET cycle.

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As a part of a program devoted to the destruction of antineoplastic agents, three chemical methods readily available in the hospital environment, viz. oxidation with sodium hypochlorite (NaClO, 5%), hydrogen peroxide (H2O2, 30%), and Fenton reagent (FeCl2.2H2O; 0.

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Ochratoxin A (OTA), a nephrotoxic and carcinogenic mycotoxin, has been implicated as an etiologic agent in the Balkan endemic nephropathy (BEN), a chronic disease affecting populations in the Balkans. Compared with unaffected individuals, patients suffering from BEN and/or urinary tract tumors were more frequently found to have a capacity for rapid debrisoquine (DB) metabolism, a metabolic reaction related mostly to cytochrome P450 (CYP) 2D in humans. Earlier studies, using female DA and Lewis rats phenotyped as poor or extensive DB metabolizers respectively, revealed a parallelism between DB-4 hydroxylation and OTA-4 hydroxylation.

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Object: Handling of genotoxic compounds commonly used in cancer chemotherapy generates contaminated wastes that require decontamination before disposal. Chemical methods are an alternative and/or a complement to incineration for the treatment of wastes and spills.

Methods: As part of a program initiated by the International Agency for Research on Cancer (IARC), 3 chemical methods readily available in the hospital environment--sodium hypochlorite (NaOCl, 5.

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The etiology of Balkan endemic nephropathy and urinary tract tumours in the rural population of the endemic regions remains unknown. As one hypothesis involves mycotoxins, a survey was carried out to investigate the possible involvement of the nephrotoxic mycotoxins ochratoxin A and citrinin. Recently, this survey was extended to screening for the presence of other mycotoxins--aflatoxins, citrinin, sterigmatocystin and zearalenone.

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The phenotypic pattern of drug biotransformation is determined by both host and environmental factors. Debrisoquine is a good probe for phenotyping individuals, as its metabolism is not affected by age, gender, smoking habits or alcohol intake. People with Balkan endemic nephropathy or with urinary tract tumours in endemic areas are more frequently extensive metabolizers of debrisoquine than are healthy people.

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1. Dark agouti (DA) and Lewis rat strains, which show a genetic polymorphism for debrisoquine-4-hydroxylation, were treated either with a single dose of ochratoxin A (OA) or for 8 weeks with 5 doses per week. Levels of OA and its 4-hydroxy metabolite (4-hydroxy-OA) excreted in urine were determined.

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As part of the joint International Agency for Research on Cancer-National Cancer Institute program for the evaluation and development of methods for the degradation of chemical carcinogens, four oxidative techniques for the degradation of hydrazines were investigated. The oxidizing agents used were as follows: sodium hypochlorite, calcium hypochlorite, potassium iodate, and potassium permanganate in sulfuric acid. In each case, at least 99% of the hydrazine initially present was destroyed; however, the potential usefulness of these methods was compromised by the formation (in some reaction mixtures) of carcinogenic N-nitroso compounds and/or unknown mutagenic species.

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