The differentiation of mammalian ovarian granulosa cells – living in the shadow of cellular developmental capacity.

The mammalian cumulus-oocyte complex (COCs) promotes oocyte growth and development during long stages of folliculogenesis and oogenesis. Before ovulation, the follicle is formed by a variety of fully differentiated cell populations; cumulus cells (CCs) that tightly surround the female gamete, granulosa cells (GCs) and theca cells (TCs) which build the internal and external mass of the follicular wall. It is well documented that CCs surrounding the oocyte are necessary for resumption of meiosis and full maturation of the gamete. However, the role of the granulosa cells in acquisition of MII stage and/or full fertilization ability is not yet entirely known. In this article, we present an overview of mammalian oocytes and their relationship to the surrounding cumulus and granulosa cells. We also describe the processes of GCs differentiation and developmental capacity. Finally, we describe several markers of mammalian GCs, which could be used for positive identification of isolated cells. The developmental capacity of oocytes and surrounding somatic cells – a “fingerprint” of folliculogenesis and oogenesis.

Rare variations of hepatic arteries in association with variable origin of gastroduodenal artery found in multidetector computed tomography angiography.

Three rare anatomical variations were found during study on hepatic arterial vascularisation in multidetector computed tomography angiography. In the first described variation the common hepatic artery (CHA) arises from the celiac trunk (CTr) and supplies right hepatic lobe. The left lobe of the liver is supplied by aberrant left hepatic artery originating as a common trunk with the left gastric artery and the splenic artery. This variation may correspond to the type 2 in Michels' classification coexisting with one of three possible patterns of the CTr division (when the CHA is the first branch of the CTr and the gastrosplenic trunk is the second one). The second variation corresponds to the very early bifurcation of the CHA arising from the CTr. Both, the right and left hepatic arteries originate separately from the CTr. The gastroduodenal artery (GDA) originates from the left hepatic artery. It may be regarded as the variation of most common type 1 according to Michels. In the third case the CHA gives raise to the GDA and terminates as the right hepatic artery supplying the right lobe of the liver only. The proper hepatic artery is missing and the left hepatic artery arises from the GDA. This variation does not correspond to any types of Michels' classification.