Partial inhibition of nitric oxide synthase activity stimulates the nuclear maturation progression of bovine cumulus-oocyte complex in the presence of hemisections of the follicular walls.

This study aimed to assess the effects of the inhibition of nitric oxide synthase (NOS) on events that modulate bovine in vitro oocyte maturation. Cumulus-oocyte complexes (COCs) were cultured with hemisections (HSs) of the follicular walls in a maturation medium supplemented with different concentrations (0.1-10.

Luteinizing hormone upregulates NPPC and downregulates NPR3 mRNA abundance in bovine granulosa cells through activation of the EGF receptor.

During folliculogenesis, the luteinizing hormone (LH) surge triggers dynamic events in granulosa cells that culminate with ovulation. The aim of this study was to evaluate if the epidermal growth factor receptor (EGFR) is required for ovulation in cattle, and if it regulates the expression of the natriuretic peptide (NP) system in granulosa cells after gonadotropin-releasing hormone (GnRH)/LH stimulation. It was observed that GnRH induces amphiregulin (AREG) and epiregulin (EREG) mRNA at 3 and 6 h after in vivo treatment, but the expression of these genes was not regulated by atrial (ANP) and C-type (CNP) NPs in granulosa cells cultured in vitro.

Molecular characteristics of granulosa and cumulus cells and oocyte competence in Nelore cows with low and high numbers of antral follicles.

The aims of this study were to investigate whether the number of antral follicles (AF) in the ovaries of Nelore cows is influenced with the developmental competence of oocytes to reach the blastocyst stage and to quantify the mRNA abundance of genes associated with folliculogenesis and oogenesis in granulosa and cumulus cells. A total of 168 cows were distributed into two experimental groups according to the number of AF, low (≤31) and high AF (≥92), which were determined based on the mean number of AF (61.14) ± SD (30.

Natriuretic peptide system regulation in granulosa cells during follicle deviation and ovulation in cattle.

Natriuretic peptides (NPs) are known to regulate reproductive events in polyovulatory species, but their function and regulation in monovulatory species remain to be fully characterized. Using a well-established in vivo model, we found that bovine granulosa cells from follicles near the deviation stage express mRNA for the three NP receptors (NPR1, NPR2 and NPR3), but not for NP precursors (NPPA, NPPB and NPPC). The abundance of NPR3 mRNA was higher in dominant compared to subordinate follicles at the expected time of follicular deviation.

The effect of age and length of gonadotropin stimulation on the in vitro embryo development of Holstein calf oocytes.

The use of oocytes recovered from prepubertal donors for in vitro embryo production has great potential for accelerating the rate of genetic gain in the dairy industry. However, these oocytes are known to be less developmentally competent than those from adult donors. In this study, we investigated the effect of age and gonadotropin stimulation in Holstein heifers subjected to oocyte collection every two weeks between 2 and 6 months of age.

Reversible meiotic arrest of bovine oocytes by EGFR inhibition and follicular hemisections.

The objective of this study was to investigate the effects of inhibiting the epidermal growth factor receptor (EGFR) pathway on meiosis blockage and resumption, mRNA expression of genes involved in oocyte maturation and cumulus expansion, and embryo development. Bovine cumulus-oocyte complexes (COCs) were cultured for 15 h in the presence of the EGFR inhibitor (AG1478) and follicular hemisections (FHS). Most of the oocytes (89.

L-arginine affects the IVM of cattle cumulus-oocyte complexes.

Nitric oxide (NO) is identified as a signaling molecule involved in many cellular or physiological functions, including meiotic maturation of cattle oocytes. This study aimed to evaluate the effect of supplementation of culture medium with the L-arginine (L-arg, NO synthesis precursor) in nuclear maturation of oocytes, concentrations of nitrate/nitrite, progesterone (P), and 17β-estradiol (E) in the culture medium; and the cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) intracellular concentrations in the cumulus-oocyte complexes (COCs) during the first hours of maturation in the presence of hemisections (HSs) of the follicular wall (control -ve). The addition of 5.

Mechanistic target of rapamycin is activated in bovine granulosa cells after LH surge but is not essential for ovulation.

The LH surge induces functional and morphological changes in granulosa cells. Mechanistic target of rapamycin (mTOR) is an integrator of signalling pathways in multiple cell types. We hypothesized that mTOR kinase activity integrates and modulates molecular pathways induced by LH in granulosa cells during the preovulatory period.

Natriuretic peptides stimulate oocyte meiotic resumption in bovine.

The aim of the present study was to evaluate the expression of mRNA encoding natriuretic peptides (NPs) and their receptors in the cumulus-oocyte complex in cattle, a monovular mammalian species, and also to investigate the role of NPs in oocyte meiotic resumption in vitro. mRNA was observed for the NP precursor type-A (NPPA), type-C (NPPC), NP receptor-1 (NPR-1), receptor-2 (NPR-2) and receptor-3 (NPR-3) in bovine cumulus cells, and NPR-2 mRNA was observed in oocytes. These results are different from those obtained in mouse and pig models.

The functional role of oxytocin in the induction of oocyte meiotic resumption in cattle.

The aim of the present study was to examine the role of oxytocin (OT) in the progesterone (P4) and prostaglandins (PGs) pathway to induce oocyte meiotic resumption. Cumulus-oocyte complexes were co-cultured with follicular hemisections for 15 h to determine the effects of different doses of OT or atosiban (ATO; oxytocin receptor antagonist) on oocyte meiotic resumption. In another experiment, we examined the effect of the interaction between P4, OT and PGs on the regulatory cascade of the oocyte meiotic resumption.

Growth factor receptor-bound protein 14: a potential new gene associated with oocyte competence.

The Grb14 protein is a member of the Grb7 protein family. This protein family acts by binding to tyrosine kinase receptors, promoting cell proliferation and differentiation. There is evidence of the involvement of tyrosine kinase factors in the bovine oocyte maturation process.

Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence.

This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation.

Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines.

The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.

Species identification and confirmation of human and animal cell lines: a PCR-based method.

Misidentification and cross-contamination of cell lines are major problems of cell cultures that can make scientific results and their reproducibility unreliable. This paper describes a PCR-based method for easily identifying or confirming the species of origin of cell lines by using a panel of oligonucleotides specific for the nine animal species most common in cell culture laboratories. A panel of 35 human and animal cell lines, whose species of origin were previously confirmed by isoenzyme assay, was studied with nine species-specific primer pairs that specifically anneal to DNA sequences codifying for human, cat, dog, mouse, rat, horse, rabbit, African Green monkey cytochrome c oxidase subunit I (cox I), and one primer pair specific for the cytochrome b gene of Chinese hamster.

The role of external beam radiotherapy in the management of differentiated thyroid cancer.

Well differentiated thyroid cancers (DTC), usually having an indolent course, are generally treated by surgery, i.e., total or near total thyroidectomy, followed by radioiodine and TSH suppressive therapy with thyroid hormone.

Cardiac output measurement by the thermodilution method: an in vitro test of accuracy of three commercially available automatic cardiac output computers.

Objective: To describe the accuracy and the reproducibility of the thermodilution flow measurements obtained using 3 commercially available cardiac output computers commonly used in intensive care units.

Design: An experimental "in vitro" study. Twelve different values of control flow (Qctr) were measured (Qmsr) using 3 different cardiac output computers (Abbott Critical Care System, Oximetrix 3 SvO2/CO Computer, Baxter Oximeter/Cardiac Output Computer SAT-1; American Edwards Laboratories, 9520 A Cardiac Output Computer).