Search results for "Ovary"
showing 10 items of 341 documents
Sex-specific windows for high mRNA expression of DNA methyltransferases 1 and 3A and methyl-CpG-binding domain proteins 2 and 4 in human fetal gonads
2006
DNA methyltransferases (DNMTs) and 5-methyl-CpG-binding domain proteins (MBDs) are involved in the acquisition of parent-specific epigenetic modifications in human male and female germ cells. Reverse Northern blot analyses demonstrated sex-specific differences in mRNA expression for the maintenance DNMT1 and the de novo DNMT3A in developing testis and ovary. In fetal testis DNMT1 and DNMT3A expression peaked in mitotically arrested spermatogonia around 21 weeks gestation. In fetal ovary transcriptional upregulation of DNMT1 and DNMT3A occurred during a very brief period at 16 weeks gestation, when the oocytes proceeded through meiotic prophase. Fetal gonads showed several fold higher DNMT3A…
The high rate of endoreduplication in the repair deficient CHO mutant EM9 parallels a reduced level of methylated deoxycytidine in DNA
2008
It has been recently proposed that hypomethylation of DNA induced by 5-azacytidine (5-azaC) leads to reduced chromatid decatenation that ends up in endoreduplication, most likely due to a failure in topo II function [S. Mateos, I. Domínguez, N. Pastor, G. Cantero, F. Cortés, The DNA demethylating 5-azaC induces endoreduplication in cultured Chinese hamster cells, Mutat. Res. 578 (2005) 33-42]. The Chinese hamster mutant cell line EM9 has a high spontaneous frequency of endoreduplication as compared to its parental line AA8. In order to see if this is related to the degree of DNA methylation, we have investigated the basal levels of both endpoints in AA8 and EM9, as well as the effect of ext…
Modulation of Base Excision Repair Alters Cellular Sensitivity to UVA1 but not to UVB¶
2007
Abstract Oxidative DNA damage has been implicated in some of the biological properties of UVA but so far not in the acute photosensitivity or cellular sensitivity. In contrast to pyrimidine dimers, oxidative DNA damage is predominantly processed by base excision repair (BER). In order to further clarify the role of oxidative DNA damage and its repair in the acute cellular response to UV light, we studied UVA1 and UVB sensitivities in three different cell model systems with modified BER. 8-Oxoguanine-DNA-glycosylase 1–/– (OGG1–/–) mouse embryonal fibroblasts and human fibroblasts in which BER was inhibited by incubation with methoxyamine were hypersensitive to UVA1, in particular to low dose…
Cisplatin-induced endoreduplication in CHO cells: DNA damage and inhibition of topoisomerase II.
2006
It has been proposed that polyploid cells that arise during a variety of pathological conditions and as a result of exposure to genotoxicants, typically in the liver, become aneuploid through genetic instability. Aneuploidy contributes to, or even drives, tumour development. We have assessed the capacity of the drug cisplatin, one of the most commonly used compounds for the treatment of malignancies, to induce endoreduplication, a particular type of polyploidy, in cultured Chinese hamster AA8 cells. Taking into account that any interference with DNA topoisomerase II (topo II) function leads to endoreduplication, we have found that treatment of the cells with this platinum compound results i…
Hypogonadism in β-thalassemic adolescents: A characteristic pituitary-gonadal impairment. The ineffectiveness of long-term iron chelation therapy
1990
The pituitary-gonadal function was studied in 18 beta-thalassemic female adolescents, 8 with delayed puberty and 10 with primary amenorrhea,treated with repeated transfusions and long-term iron chelation therapy by subcutaneous infusion. A 100 micrograms gonadotropin-releasing hormone (GnRH) test, a double-bolus GnRH test after estradiol administration in non-responders, a 400 micrograms thyrotropin-releasing hormone (TRH) test and a 'high dose' human menopausal gonadotropin (hMG) test were performed. LH and FSH peak levels were significantly lower in thalassemic patients than in controls, both in the 100 micrograms GnRH test (LH was 4.3 +/- 0.7 mIU/ml vs 40.8 +/- 6.0 mIU/ml and FSH 3.3 +/-…
Diagnosis of polycystic ovary syndrome: from NIH criteria to ESHRE-ASRM guidelines.
2004
In the past, the diagnosis of polycystic ovary syndrome (PCOS) was based on National Institute of Health (NIH) criteria (hyperandrogenism and chronic anovulation) or on sonographic findings of polycystic ovaries. Diffe-rences in diagnosis criteria made it difficult to compare the data of studies coming from different countries. Moreover, there was criticism of both the methods used. In 2003, at a joint meeting of the European Society for Human Reproduction (ESHRE) and the American Society of Reproductive Medicine (ASRM), new guidelines for the diagnosis of PCOS were suggested. According to these guidelines, it is possible to reach a diagnosis of PCOS when at least 2 of these 3 elements are …
Pseudoallencotyla gen. n., a new genus for Allencotyla pricei (Kritsky, Noble et Moser, 1978) (Monogenea: Heteraxinidae), with a key to genera of Het…
2003
In this study, we clarify the taxonomic status of Allencotyla pricei based on a re-examination of paratypes and voucher specimens. Four important characters are added to previous descriptions: the vagina is ventral; the cirrus is absent; the eggs are fusiform and have two polar filaments (one about 3.5 times longer than the other); and, there are two flat sclerites at each side of the dorsal trident-shaped sclerite in the clamps. A comparison of A. pricei with species from all the genera of the Heteraxininae, including Allencotyla mcintoshi, indicates that A. pricei has several exclusive characters, i.e., a ventral vagina, vaginal armature, two additional dorsal sclerites in the clamps, a v…
Adjuncts for ovarian stimulation: when do we adopt “orphan indications” for approved drugs?
2009
Several drugs, shown to be safe for other uses, have proven to be highly effective adjuncts for ovarian stimulation. The authors evaluate these "orphan" indications and make recommendations so that more patients will benefit from their use.
Metformin induces lipid changes on sphingolipid species and oxidized lipids in polycystic ovary syndrome women.
2019
Metformin is one of the treatments used for pcoS pathology decreasing body weight, plasma androgen, FSH and glucose levels. Unfortunately, there is little known about metformin’s effects on lipid metabolism, a crucial process in pcoS pathology. We have employed a lipidomic approach to explore alterations in the plasma lipid profile of patients with PCOS following metformin treatment. The aim is to offer new insights about the effect of metformin in PCOS patients. Plasma samples were obtained from 27 subjects prior to and following 12 weeks of metformin treatment. A detailed biochemical characterization and lipidomic profile was performed. Metformin reduces BMI, HOMA-IR, fSH and androstenedi…
Dopamine agonist cabergoline reduces hemoconcentration and ascites in hyperstimulated women undergoing assisted reproduction.
2007
Abstract Context: Ovarian hyperstimulation syndrome (OHSS) results from increased vascular permeability (VP) caused by ovarian hypersecretion of vascular endothelial growth factor (VEGF), which activates its receptor-2. In animals, the dopamine receptor 2 agonist cabergoline (Cb2) inactivates VEGF receptor-2 and prevents increased VP. Objective: Our objective was to test whether Cb2 reduces VP and prevents OHSS in humans. Design: We conducted a prospective, randomized, double-blind study on oocyte donors at risk of developing OHSS (>20 follicles, >12 mm developed, and >20 oocytes retrieved). Interventions: Cb2 0.5 mg/d (n = 37) or a placebo (n = 32) was administered fro…