Liver hematopoiesis and hematopoietic microenvironment - three dimensional reconstruction and immunohistochemical observation of CD markers

胎肝造血期分为4个阶段：I期，第10天开始造血；II期，第11天和第12天造血室体积扩大；III期，第13天和第14天造血室体积达到高峰；IV期，第15天后造血功能恢复。在第I-II期，造血干细胞似乎从肝窦腔进入原始肝索，在肝母细胞之间形成集落。在第III期，造血集落形成椭圆形的集落，形成一个造血的结构单位，然后红系集落以索状出现。在IV期，这些索状病灶变得破碎，肝细胞索内出现圆形孤立性病灶，呈曲线状。IV期造血灶中含有大量的粒细胞、淋巴细胞和红系细胞，肝母细胞体积在妊娠13天前基本保持不变，之后逐渐增大，…更有安全感。HI期肝母细胞之间通过短的胞质投射相互接触。&钙粘附素介导的贴壁连接出现。在H-III期，除了贴壁连接外，小桥粒似乎将肝母细胞结合在一起，肝母细胞之间可以识别出胆小管的切片轮廓。IE期胆小管周围既有紧密连接又有缝隙连接，并出现粘附性连接、桥粒连接、紧密连接和缝隙连接四种类型的特化连接。为了区分淋巴细胞和髓系造血细胞，并确定淋巴细胞亚群，用小鼠抗CD单抗。在对照染色中，抗体能在成人脾中特异性地染色T或B淋巴细胞，但在胎儿和新生儿肝脏中不能获得特异的结果。抗小鼠单抗的免疫组织化学染色被认为是小鼠胚胎器官未来的任务。较少

In fetal liver hematopoiesis, four stages were identified : Stage I, onset of hematopoiesis at 10 days, Stage II, expansion of the volume of the hematopoietic compartment at ll and 12 days, Stage III, peak in the volume of the hematopoietic compartment at 13 and 14 days, and Stage IV, involution of hematopoiesis after 15 days. During Stages I-II, hematopoietic stem cells appeared to move from the sinusoidal lumina into primitive hepatic cell cords to give rise to colonies among hepatoblasts. At Stage III, the hematopoietic colonies formed ellipsoidal foci as a structural unit of hematopoiesis, and then the erythropoietic foci appeared as cords. At Stage IV, these cord-shaped foci became disrupted, and round solitary foci appeared within the hepatic cell cords on meandering sinusoids. Hematopoietic foci in Stage IV contains numerous granulocytes and lymphocytes as well as erythroblasts.The hepatoblast volumes appeared constant until 13 days of gestation, and then showed a gradual increa … More se. Hepatoblasts at stage HI made contact with one another by short cytoplasmic projections. ＆cadherin mediated adherens junctions were found. At stage H-III, in addition to the adherens junctions, small desmosomes appeared to bind hepatoblasts together, and section profiles of biliary canaliculi could be recognized between hepatoblasts. At the IE stage, both tight junctions and gap junctions appeared around the biliary canaliculi, and four types of specialized junctions, i. e., adherens junctions, desmosomes, tight junctions and gap junctions, appeared fully organized.In order to differentiate lymphocytes from myeloid hematopoietic cells and to determine lymphocytesubclasses, anti-mouse anti-CD monoclonal antibodies were used. In control staining, the antibodies were ableto stain T or B lymphocytes specifically in adult spleens, but, in fetal and neonatal livers, specific results could no be obtained. Immunohistochemical stainings with the anti-mouse monoclonal antibodies were considered to be future tasks in mouse fetal organs. Less