The present paper shows through conventional light microscopy, silver nitrate impregnation and Transmission Electron Microscopy, the changes in nuclear activity that occurs in the ovary cells during vitellogenesis of Apis mellifera (Linnaeus, 1758). The material impregnated by silver nitrate was detected in nurse cells, oocyte germinal vesicle and follicular cells, whose amounts are greater in ...

oocyte maturation and embryo development are controlled by intra-ovarian factors such as steroid hormones. progesterone (p4) exists in the follicular fluid that contributes to normal mammalian ovarian function and has several critical functions during embryo development and implantation, including endometrial receptivity, embryonic survival during gestation and transformation of the endometrial...

An immunofluorescence double labeling assay was used to examine the kinetics of intestinal B lymphocytes with concurrent expression of multiple antibody isotypes in the mucosal tissues of rats infected with Trichinella spiralis (TS) muscle larvae for 1 to 15 days. As compared to the uninfected controls (day 0), the non-Peyer's patch tissues of the small intestine contained a significantly incre...

Testicular biopsy specimens from 16 fertile and 10 subfertile men with normal male karyotype were studied quantitatively to provide histological and cytogenetic data for a basis of reference in assessing abnormalities of spermatogenesis. Histological studies included estimation of the proportion and activity of germinal epithelium and an assessment of tubular morphology. In cytogenetic preparat...

We introduce a new model for the dynamics of centroblasts and centrocytes in a germinal center. The model reduces the germinal center reaction to the elements considered as essential and embeds proliferation of centroblasts, point mutations of the corresponding antibody types represented in a shape space, differentiation to centrocytes, selection with respect to initial antigens, differentiatio...

Follicular dendritic cells (FDC) show homo- and heterocellular metabolic coupling through connexin 43 (Cx43) gap junctions and support B cell selection and maturation in germinal centers. In follicular lymphomas B cells escape apoptosis while FDC develop abnormally. Here we tested Cx43 channels in reactive FDC development and follicular lymphomas. In culture, the treatment of FDC-B cell cluster...

Gonads from White Leghorn chick embryo of various ages ranging from 4 to 10 days of incubation, were fixed in half-strength Karnovsky's fixative, osmicated and embedded in Araldite. Thin sections were stained with urany] acetate and lead citrate. Our observations were especially concentrated on the germinal epithelium. Two cytological characteristics not previously described in embryonic chick ...

Diffuse large B-cell lymphomas (DLBCL)s, the most common type of Non-Hodgkin’s Lymphoma, constitute a heterogeneous group disorders including different disease sites, strikingly diverse molecular features and profound variability in clinical behavior. Molecular studies trials have partially revealed underlying causes for this made possible recognition some variants susceptible specific therapeu...

In embryonic development of the leech Helobdella triserialis, each of the four paired positionally identifiable, ectodermal teloblasts (N, O, P, and Q) generates a bandlet of blast cell progeny that merges with ipsilateral bandlets into a germinal band. Left and right germinal bands coalesce into the germinal plate which gives rise to the segmental tissues of the leech and wherein the progeny o...