Cumulus expansion and oocyte maturation are central processes in ovulation. Knowledge gained from rodent and other mammalian models has revealed some of the molecular pathways associated with these processes. However, the equivalent pathways in humans have not been thoroughly studied and remain unidentified. Compact cumulus cells (CCs) from germinal vesicle cumulus oocyte complexes (COCs) were ...

Background: The study was carried out to investigate the relationship between the development potential and the diameter of ovine oocytes. Materials and Methods: Ovaries collected from a local abattoir were transported to the laboratory within 1-3 h of slaughter. The oocytes from follicles (2-6 mm in diameter) were recovered by aspiration and stored in a preincubated (at 38.6 C, 5% CO2 and maxi...

In the process of oocyte maturation, gonadotrophins are believed as main stimulators for oocyte meiosis resumption. However, which gonadotrophin (i.e. FSH or LH) is the key hormone in this process is still unknown. This study indicated a close relationship between LH and FSH on activating meiotic maturation of oocyte in vitro. FSH efficiently induced oocyte meiosis at concentration of 50 IU/L, ...

To fuse with oocytes, spermatozoa of eutherian mammals must pass through extracellular coats, the cumulus cell layer, and the zona pellucida (ZP). It is generally believed that the acrosome reaction (AR) of spermatozoa, essential for zona penetration and fusion with oocytes, is triggered by sperm contact with the zona pellucida. Therefore, in most previous studies of sperm-oocyte interactions i...

The adsorption properties of structurally well defined bimetallic Pt/Ru(0001) surfaces, consisting of a Ru(0001) substrate partly or fully covered by monolayer Pt islands or a monolayer Pt film, were studied by temperature programmed desorption (TPD) using CO and deuterium as probe molecules. Additionally, the adsorption of CO was investigated by infrared reflection absorption spectroscopy (IRA...

We synthesized a new class of O2 electrocatalysts with a high activity and very low noble metal content. They consist of Pt monolayers deposited on the surfaces of carbon-supported nonnoble metal-noble metal core-shell nanoparticles. These core-shell nanoparticles were formed by segregating the atoms of the noble metal on to the nanoparticles' surfaces at elevated temperatures. A Pt monolayer w...

Vero cells and Madin Darby Canin Kidney cells were exposed to Salmonella typhimurium sub spp. enteritis to study the interaction and invasion. The monolayer cell line bottles were selected and sub cultured. The sub cultured bottles were incubated at 37°C in 5% CO atmosphere for the formation of monolayer. 2 After the complete confluence of cells, the bottles were selected for the inoculation of...

31 32 In the growing follicle, communication between the oocyte and its surrounding follicular 33 cells is essential for normal oocyte and follicular development. Maturation of the fully34 grown oocyte in vivo is associated with the loss of cumulus cell-oocyte gap junctional 35 communication, preventing entry of meiotic-modulating factors such as cAMP into the 36 oocyte. We have previously show...

We previously reported that when midkine (MK), a heparin-binding growth differentiation factor was used in in vitro maturation (IVM) culture of bovine cumulus-enclosed oocytes (CEOs), their developmental competence to the blastocyst stage after in vitro fertilization (IVF) was enhanced and the effect of MK might be mediated by its action upon mural granulosa cells and cumulus cells that closely...