The fine structure of the cells in connective tissue of the human fetal membranes at full term of normal pregancy was examined by electron microscopy. In addition to fibroblasts and Hofbauer's cells,the connective tissue of human fetal membranes contains numerous myofibroblasts.Since the myofibroblasts are able to contract similarly to smooth muscle cells,we suggest that they could contribute, along with the microfibrils which possess elastic property,to the protection of fetal membranes from over distension.

Freeze-fracture technique was used to study the tight junctions in the glandular epithelium of normal human endometrium at different phases of the menstrual cycle. The tight junctions were consisted of a few strands and extended less deeply along the lateral plasma membrane during the early proliferative phase of the cycle.The number of strands, but not the depth of the tight junctions, significantly increased (P0.05) during the late proliferative phase and early secretory phase as compared to the mid-proliferative phase. During the midsecretory phase, the number of strands as well as tight junctional depth significantly increased(P

Abstract Studying the fine structure of the human fetal cndometrinm, we found simple and complex nuclear bodies in the epithelium.The estrogenic stimulation can enhance the formation and conversion of simplex nuclear bodies into complex nuclear bodies. Since the maternal estrogen and progesterone can enter the fetal blood stream through the placenta, we suppose that the formation of complex nuclear bodies in the fetal endometrial epithelium may be due to the stimulation of the maternal estrogen. The rRNA synthesized by complex nuclear bodies can elevate the protein synthesis for the cell proliferation of the endometrial epithelium.Because the formation of nuclear bodies can be prevented by progesteronic stimn tion, the presence of nuclear bodies in fetal endometrial epithelium may be related to the relative concentration of estrogen and progesterone circulating in the fetal blood stream and to the n mer of their receptors in the epithelium.

On studying the morphology of spiral arteries in the human placental bed, we found, both in normal term pregnancy and in prolonged pregnancy, there are not only physiological changes such as invasion of trophoblastic cells, disappearance of smooth cells and elastic tissues, but also infiltration of erythrocytes and presence of foam cells in the vessel wall. Since the foam cells are found morphologically very similer to some trophoblastic cells and since the trophoblastic cells have phagocytotic function, we assume that the foam cells may originate from the trophoblastic cells.Besides, we found frequently also thrombosis, thickening of intima and infiltration of abundant erythrocytes in the uterine spiral arteries of prolonged pregnancy. Since these phenomena can diminish blood supply to the placenta, we suppose that they are the main factors leading to placental senescence and to decline in placental functions.

Objective To investigate the effects of mifepristone on the ultrastructure of Hofbauer cells in human early pregnant placenta. Methods Twenty 6-9 week pregnant women with indications of pregnancy termination were recruited and randomlied to mifepristone (n=10) and D & C group (n=10).Villi were collected and studied with transmission electron microscope. Results In comparison with the control group,the ultrastructure of Hofbauer cells of mifepristone group showed the following changes: the cells were markedly edematous. The number of cytoplasmic processes of Hofbauer cells deceased obviously. In the cytoplasm of Hofbauer cells,the size of vacuoles enlarged and of mitochondrias minimized.Rough endoplasmic reticulum and Golgi complex were under-developed.Lysosomes were rare.The nuclei enlarged and showed irregular shape. Conclusions Mifepristone may change the phagocytosis'water and electrolyte transportation and immunological function of Hofbauer cells by influencing the ultrastructure of the Hofbauer cells.Therefore it can influence the development of pregnancy.

Objective To compare the effects of resuscitation at pure oxygen environment(100% oxygen) or room air environment (21% oxygen) on the uhrastructure of cerebral cortical neurons in hypoxic neonatal rat.Methods Twenty Sprague-Dawley neonatal rats aged 7 days were divided into the pure oxygen environment (POE) and room air environment groups (RAE) after hypoxia,and each group was divided again into 24 h and 72 h subgroups.The pups were placed in an incubator containing 8% O_2 to be at acute hypoxia continued for 2.5 h.The pups were reoxygenated immediately after the above mentioned hypoxia.The pups of POE group were then placed in an incubator containing 100% oxygen and the flow time was 30 rain.The pups of RAE group were reoxygenated with room air in an incubator for 30 rain.According to the planned time points the pups were sacrificed and the brain was removed at 24 h and 72 h after treatment,respectively.The tissue of frontoparietal cortex of the fight cerebral hemisphere was prepared for transmission electron microscopic examination.Results In each reoxygenation group,edema was found in the neurons,neuropil and intercellular space.In the RAE 24 h group,the nuclear membrane in neurons was unclear,the amount of cell organelles was reduced,the mitochondria were swollen with damages of cristae.The rough endoplasmic reticulum was dilatated or vaeuolized and with reduction of ribosomes.The Golgi complex was vacuolized.The number of lysosomes was obviously increased.In the RAE 72 h groups,the changes were similar to those of the former group,but apoptotic-like nuclei and necrotic neurons were more frequently seen. The cellular damages of POE 24 h group were milder than those of RAE 24 h group. The mitochondria and rough endoplasmie reticulum were more abundant and showed less pathological changes in the POE 72 h group as compared with those of RAE 72 h group. Conclusion The rats of POE reoxygenation display milder ultrastructural damages, less apoptosis, necrosis and edema in cerebral neurons than those in rats after RAE reoxygenation.The protective effect of POE resuscitation on cerebral damage of hypoxic neonate rats is superior to that after RAE resuscitation. This hypoxic neonatal rat model may serve as a suitable animal model for research on cerebral cortex neurons caused by hypoxia.

AIM: To investigate the apoptosis and Bcl-2/Bax expression in the early follicles of women at reproductive age. METHODS: 12 ovarian specimens were collected from reproductive women (aged 23-38 years) undergoing gynaecological operation. Histopathological examination of these specimens was performed to confirm its' morphological normalities. Using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay and immunohistochemistry method, cell apoptosis and Bcl-2/Bax expression were examined in the early follicles including mainly primordial, intermediary and primary follicles. RESULTS: 18.75% of the oocytes were found TUNEL positive in the early follicles, but no granulosa cells in these follicles were found TUNEL positive. Bax expression was detected in 76.07% of the oocytes in the early follicles, but Bcl-2 expression was negative in these oocytes. In addition, Bcl-2/Bax expression were not present in the granulosa cells in early follicles. CONCLUSION: The oocyte apoptosis occurs in the early follicles of reproductive woman, and pro-apoptotic protein Bax may play a role in regulating this process. It suggests that Bax mediated oocyte apoptosis may be the molecular mechanism of the early follicle atresia in the ovaries of reproductive woman. [

BACKGROUND:Cytotrophoblasts in placental cell components plays an important role in fetal immunological tolerance.Placental mesenchymal stem cells(pMSCs)have potential of multiple differentiation and inhibition of lymphocyte proliferation.However,conventional methods cannot acquire a large amount of purified human cytotrophoblasts or pMSCs.OBJECTIVE:To establish a method to obtain large placenta tissue,and harvest plenty of cytotrophoblasts and pMSCs with high purity and activity.METHODS:Human placenta tissues were dissected,minced,and dissociated in trypsin and DNAse I.The dissociation was performed in three stages of incubation at 180 r/min for 20 minutes at 37 ℃ The digesting suspension was filtered using a 200 mesh strainer before separated by Percoll gradients.The cytotrophoblast cells and pMSCs fractions were collected respectively.Fibroblasts of cytotrophoblast cells fraction were removed by differential adhesion.The pMSCs were seeds on 75-cm2 flask directly for culture.The dissociation of placenta tissue was observed.The number of harvesting cytotrophoblasts was quantified and Cytokeratin 7 expression was tested.The pMSCs primary culture time,cell passage,induced osteoblast differentiation were observed.The cell surface makers were also detected.RESULTS AND CONCLUSION:After digesting in trypsin and DNAse I,there was only little residue left.(5.48±1,98)×10~8 cytotrophoblasts were obtained after differential adhesion.(90±4.36)% of these cells were positive for Cytokeratin 7.At 19-21 days after pMSCs reached approximately 90% confluency,the cell number was(1.96±0.24)×10~6.The subcultre cells could be passaged again in 4 or 5 days.Flow cytometric analysis of pMSCs showed that the cells expressed CD29,CD44 and HLA-ABC intensively and were negative for CD34,CD45,CD14 and HLA-DR.pMSCs differentiated into osteoblast-like cells after induction,which stained bright salmon pink by Alizarin Red.Dissociating the placenta tissue in trypsin and DNAse I in combination with discontinuous Percoll gradient separation obtained a large number of cytotrophoblasts and pMSCs recovered from placenta tissue,with high purity and activity.

AIM: To investigate the effect of mifepristone on natural killer(NK) subpopulations of peripheral blood and decidua in early pregnancy. METHODS: Flow cytometry was used to detect the expression of CD56 and CD16 on lymphocytes of decidua and peripheral blood in early pregnancy, mifepristone-treated pregnancy. RESULTS: The percentages of different natural killer subsets in peripheral blood between early pregnancy and mifepristone-treated pregnancy were almost identical. The serum levels of estradiol and progesterone in mifepristone-treated pregnancy were slightly higher than in early pregnancy. The percentage of decidual CD56+NK cell in early pregnancy was significantly higher than in mifepristone-treated pregnancy. The CD56+NK cells were predominant lymphocyte population of decidua in mifepristone-treated pregnancy, but in which the CD56+CD16+ and CD16+NK cells were major lymphocyte subpopulations of peripheral blood. CONCLUSION: Mifepristone acted principally on feto-maternal interface, it blocked the proliferation and differentiation of decidual CD56+NK cells and induced embryo immune rejection.

AIM: To investigate the influence of mifepristone on ultrastucture of human endometrium in the early secretory phase. METHODS: Endometrial tissue was obstained from 10 patients of reproductive age, who underwent a hysterectomy within 1 week postovulatory for gynecologic diseases not involving the endometrium. Patients were divided into mifepristone group ( n =5) and control group ( n =5) randomly. Each patient in the mifepristone group had taken 25 mg mifepristone per os 24 h before the operation was performed, while none of the control group had taken mifepristone. After removal of uterus, endometrial tissue was immediately acquired and prepared for electron microscopic examination. RESULTS: In comparison with the control group, the endometrial tissue in mifepristone group displayed the following distinctly morphological changes: (1) In the endometrial epithelium neither nucleolar channel system nor giant mitochondrium was seen, and subnuclear glycogen accumulation was seldom observed, but giant lysosomes were frequently found. (2) The intercellular spaces of the epithelium were narrow and straight, the indigitations of lateral plasma membranes were rarely visible. (3) Cytolysis and karyopyknosis of stroma cells and extravasal red cells were repeatedly observed. CONCLUSION: The above mentioned morphological changes in endometrium in the early secretory phase caused by mifepristone are undoubtedly sufficient to prevent implantation. Consequently, mifepristone may have a contraception effect.