Search results for "VITRO"
showing 10 items of 2786 documents
APOPTOTIC ANALYSIS OF CUMULUS CELLS FOR THE SELECTION OF COMPETENT OOCYTES TO BE FERTILIZED BY INTRACYTOPLASMIC SPERM INJECTION (ICSI)
2015
Oocyte quality is one of the main factors for the success of in vitro fertilization protocols. Apoptosis is known to affect oocyte quality and may impair subsequent embryonic development and implantation. The aim of this study was to investigate the apoptosis rate of single and pooled cumulus cells of cumulus cell–oocyte complexes (COCs), as markers of oocyte quality, prior to intracytoplasmatic sperm injection (ICSI).We investigated the apoptosis rate by TUNEL assay (DNA fragmentation) and caspase-3 immunoassay of single and pooled cumulus cells of COCs. The results showed that DNA fragmentation in cumulus cells was remarkably lower in patients who achieved a pregnancy than in those who di…
Studies on zymogenicity and solubilization of chitin synthase from Candida albicans
1985
The zymogenic form of the chitin synthase present in mixed membrane preparations was extracted by digitonin treatment. The residual extracted membranes exclusively retained the basal activity. Trypsin activation of the zymogenic form of the enzyme did not modify the digitonin solubilization characteristics of the original zymogenic form, suggesting significant differences between ‘in vivo’ activation of chitin synthase and that carried out by trypsin ‘in vitro’.
Ocular gelling microspheres: in vitro precorneal retention time and drug permeation through reconstituted corneal epithelium.
2008
Purpose: The model drug norfloxacin (NOR)was encapsulated into trehalose (TRH) and hydroxyethylcellulose(NAT) microspheres to obtain a novel gelling ophthalmic delivery system for prolonged release on corneal tissue. Methods: We assessed NOR release from microspheres, prepared by the emulsion-solvent evaporation method. A new in vitro tear turnover model, including inserts containing reconstituted human corneal epithelium (RHC), was designed to evaluate the TRH/NAT microspheres’ precorneal retention time. Bioadhesive properties of TRH/NAT microspheres were validated by using drug-loaded microspheres prepared with gelatine (GLT) commonly used as reference material in adhesion studies. Result…
Nuclear receptor NR5A2 and bone: gene expression and association with bone mineral density
2011
El pdf del artículo es el manuscrito de autor (PMCID: PMC3682472).-- et al.
Expression and regulation of mPer1 in immortalized GnRH neurons.
2003
Hypothalamic GnRH (gonadotropin-releasing hormone) neurons play a critical role in the initiation and maintenance of reproduction competence. Using the mouse GnRH neuronal cell line, GT1-7, we have characterized the expression of the gene mPer1, a recognized key element of the mammalian circadian clockwork. Both mPer1 transcripts and the 136 kDa mPER1 gene product could be detected in these cells. Immunocytochemical analysis also confirmed expression of mPER1 both in vitro and in vivo in GnRH neurons. Activation of cyclic AMP signalling pathways in vitro elevated GnRH secretion as well as mPer1 expression and nuclear mPER1 immunoreactivity. As mPER1 is known to feedback on transcriptional a…
Effects of sulphonylureas on spontaneous motility and induced contractions in rat isolated uterus
1986
Abstract To clarify the action of sulphonylureas on calcium, the effect of tolbutamide and ghbenclamide has been investigated on a Ca-dependent process, the contractile activity of uterine smooth muscle. Both sulphonylureas antagonized the contractions evoked by CaCl2 in a non-competitive manner when the uterus was maintained in depolarizing solution and did not affect the spontaneous contractions of rat uterus. The capacity of tolbutamide and ghbenclamide to relax vanadate-induced contraction of rat uterus in Ca-free medium suggests that sulphonylureas may have an intracellular site of action related to cytosolic free Ca levels, or effect a reduction in Ca action.
In vitro synthesis of dopamine and noradrenaline in the isolated rat pineal gland: day-night variations and effects of electrical stimulation.
1989
: Isolated rat pineal glands were incubated in vitro in a medium containing [I4C]dopamine or [14C]tyrosine, and the tissue contents of l4C-labelled and total dopamine and noradrenaline were determined by HPLC followed by electrochemical detection and scintillation spectrometry. During incubation with [l4C]dopamine, the labelled amine accumulated in pineal glands and was partially converted into [l4C]noradrenaline. Nomifensine, a neuronal amine uptake blocker, largely inhibited the accumulation of [l4C]dopamine and the formation of [14C]noradrenaline. These experiments demonstrated dopamine β-hydroxylase activity in the sympathetic nerves of the pineal gland. During incubation with [14C]tyro…
In vitro effects of estradiol, testosterone, and progesterone on 5-methoxyindole content, cyclic adenosine 3',5'-monophosphate synthesis, and norepin…
1986
To examine the effects of estradiol, testosterone, or progesterone on cyclic adenosine 3',5'-monophosphate (AMP) accumulation, 5-methoxyindole levels, and norepinephrine (NE) release by the female guinea pig pineal complex, samples of the deep, intermediate, or superficial portions of the complex were incubated in vitro with varied concentrations of either hormone. Exposure for 10 minutes to physiological amounts of estradiol (10 nM) or to 100 microM NE increased significantly cyclic AMP levels to the same extent in the three pineal regions. A maximal effect on cyclic AMP accumulation was observed at 100-nM concentrations of estradiol, with a tendency to return to basal levels at 1-10 micro…
Concentrations of ovarian proteohormones as biological markers for the outcome of assisted reproductive technology
2002
Objective: To assess whether the ovarian proteohormones inhibin A and B, pro-alpha-C and activin A could act as direct biological markers of a poorer or better response to ovulation induction or clinical conception through assisted reproductive technology (ART). Methods: Seventy-seven women who underwent ART were included in the study and were divided into two groups: (i) 46 women with sonographically documented follicular maturation; and (ii) 36 women who demonstrated inadequate follicle development. Blood samples were analyzed for inhibin A, inhibin B, pro-alpha-C, activin A and estradiol (E2) at day 3 of stimulation with recombinant follicle-stimulating hormone (rFSH) after pituitary dow…
Relaxation induced by N-terminal fragments of chromogranin A in mouse gastric preparations.
2007
Abstract A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro , the effects of the recombinant vasostatin 1–78 (VS-1), CGA 7–57 and CGA 47–66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7–57 and CGA 47–66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53–57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), b…