Ultrastructural characterization of bovine umbilical cord blood cells / Caracterização ultra-estrutural das células sanguíneas do cordão umbilical bovino

The umbilical cord blood (UCB) is an important source of pluripotent stem cells, which motivated researches on ontogeny and transplantation. The morphological characterization of umbilical cord cells is the first step to establish subsequent experiments on these areas. Although some information on humans can be found, no data on UCB is available for bovines. Therefore, this work is the first attempt to conduct an ultrastructural characterization of bovine umbilical cord blood. Blood was collected from the umbilical cord of twenty fetuses by punction of the umbilical vein. Samples were processed for whole leucocytes observation by centrifugation and the buffy coat was collected. Cells were washed and pelleted and prepared according to the standard protocol of the transmission electron microscopy. The presence of cells with morphologic characteristics compatible with the precursors from the erythrocytic, neutrophilic, eosinophilic, basophilic, and lymphocytic lineages was observed. Atypical cells with peculiar morphological features, strongly similar to apoptotic cells, were seen. Bovine neutrophils with three types of cytoplasmic granules were also found in the blood. The ultrastructural characteristics of observed bovine UCB cells where similar to those found in other species, suggesting that bovines could possibly constitute an experimental model for approaches on UCB cells research.

O sangue de cordão umbilical (SCU) é uma importante fonte de células progenitoras pluripotentes, que motiva pesquisas em ontogenia e transplantes. A caracterização morfológica das células de cordão umbilical é o primeiro passo para se estabelecer experimentos subsequentes nessas áreas. Embora algumas informações sobre SCU em humanos possam ser encontradas, não existe nenhuma informação disponível sobre elas em bovinos. Portanto, este trabalho é a primeira tentativa de se conduzir uma caracterização ultra-estrutural do sangue de cordão umbilical bovino. O sangue foi coletado do cordão umbilical de 20 fetos por punção da veia umbilical. As amostras foram processadas para observação dos leucócitos totais por centrifugação pela coleta do botão leucocitário. As células foram lavadas, peletizadas e preparadas de acordo com protocolo padrão para microscopia eletrônica de transmissão. A presença de células com características morfológicas compatíveis com precursores das linhagens eritrocítica, neutrofílica, eosinofílica, basofílica e linfocítica foram observadas. Células atípicas com características morfológicas peculiares muito semelhantes a células em apoptose foram observadas. No sangue do cordão umbilical também foi encontrado neutrófilos bovinos apresentando três tipos de grânulos citoplasmáticos. As características ultraestruturais do SCU bovino foram semelhantes às encontradas em outras espécies, sugerindo que esta espécie possa servir como modelo experimental para abordagens em pesquisa sobre sangue de cordão umbilical.

Expression and significance of CD_(34),AC133,C KIT,STRO 1 in pterygium / 眼科研究

Background Many researches have reported the high proliferation ability of pterygium tissue.However,the origin of cells in pterygium tissue and their role in pathogenesis and recurrence of pterygium are below understand up to now.Objective This study is to explore the role of bone marrow derived stem cells and progenitor cells in the pathogenesis of pterygium.Methods Informed consent was obtained from 12 patients with the pterygium stretching the edge of the pupil prior to this trail.Pterygium specimen was obtained from 8 patients with primary pterygium and 4 patients with recurrent pterygium during the operation.The normal conjunctival tissue was obtained from the location of 10 mm from the pterygium in the operation eye.The expression levels of marker of the primitive haematopoietic progenitors(AC133),marker of the haematopoietic progenitor cells and endothelium (CD_(34)),marker of haematopoietic and stromal progenitor cells (C KIT ),and differentiation antigen of bone marrow fibroblast cells and nonhaematopoietic progenitor cells 1 (STRO 1) were detected by using immunohistochemistry.Results Various progenitor cell markers originated from bone marrow,including CD_(34),AC133,C KIT,STRO 1,were positively expressed in pterygium specimen rather than normal conjunctival specimen mainly in the basal epithelium or stroma of pterygia tissue.Majority of the positive cells were seen in the head of pterygium.C KIT positive cells were observed mainly in the basal epithelium and stroma of pterygium.The morphology of positive cells varied upon different distribution.Fibroblast like and spindle shaped positive cells were seen in the stroma layer of pterygium,and round or ovoid shaped cells were in basal epithelial layer.The distribution and shape of positive cells for AC133 and CD_(34) were similar to ones of C KIT but numbers of cells were varied between them.C KIT,AC133 and CD_(34) positive cells were coexpressed in basal epithelium and vascular endothelium.Expression of STRO 1 was found in the stroma layer not in the basal epithelium of pterygium.Similar distribution,numbers and shape of positive cells were seen between recurrent and primary pterygium.Conclusion The cells with stem cells markers and progenitor cells markers originated from bone marrow may play a role in the pathogenesis of pterygium.