Objective:To investigate the effect of steroid hormones on distribution of uterine natural killer(uNK)cells in the mouse uterus.Methods:A unique uNK cell marker, Dolichos biflorus agglutinin(DBA)lectin was used to localize uNK cells in the ovariectomized and ovarian steroid hormone-treated mouse uterus by immunohistochemical staining.Results: After estrogen(E_2)was administered in the ovariectomized mice, uNK cells were distributed in the stroma of uterine mesometrial pole,as round, immature and small lymphocyte-like cells.With the progesterone(P_4)administered, the immunostaining results showed that DAB-lectin staining were mainly distributed in the vascular endothelial cells.With the combination of E_2 and P_4, DAB-lectin staining was distributed in the matrix of the uterus,seen as a number of small round uNK cells or some as vascular endothelial cells.The effects could be completely abolished by specific antagonists of their nuclear receptors(estrogen and progesterone receptor).Conclusion: The distribution of uNK cells in mouse uteri is collaboratively regulated by estrogen and progesterone.The endometrial uNK cells may be involved in the mechanism of the fetal protective immune reaction during pregnancy.

BACKGROUND:Studies have found that smal intestinal submucosa that is directly implanted into the lesion cannoteffectively promote celgrowth and differentiationin vivoandin vitro, because of its smal pore size and poor permeability.
OBJECTIVE:To establish the smal intestinal submucosa sponge and to explore its morphological characteristics.
METHODS:Porcinesmall intestinal submucosa was prepared by physiochemical method. Thenthe small intestinal submucosa with the mass fraction of 1%, 2%, 3% and 4% was cross-linked by 50, 100 and150 mmol/L 1-ehyl-3-(3-dimethylaminopropyl) carbodimide hydrochloride, respectively, so as to obtain smal intestinal submucosa sponge, whose morphology was detected by lighting and scanning electron microscope. In the meanwhile, smal intestinal submucosa as control group, and smal intestinal submucosa sponge as test groupwere intramuscularly implanted into the back of rats,respectively. At 1, 2 and 3 weeks after implantation, histological changes andimplantdegradation were observed by hematoxylin-eosin staining.
RESULTS AND CONCLUSION:The smal intestinal submucosa sponge, which was prepared by the smal intestinal submucosa with the mass fraction of 1% and 100 mmol/L cross-linking agent, had elastic and close space structure, uniform pore size and regular structure, so it was selected as the implant into themuscle.At 1 week after implantation, in the test group,the mesh sponge had the complete structure withfew neutrophils, lymphocytes and giant cel reaction, andsoft tissue hyperplasia and migration surrounding the implant appeared;in the control group,there were numerous inflammatory cels, and wound adhesion and little migration of surrounding tissues could be found.At 3 weeks, inflammatory cels mostly disappeared, and fibroblast-like cels and vascular components appeared, with thinner and regular colagen fiber bundles, and connective tissue-like structures could be found. In contrast, the control group stil had numerous inflammatory cels and few colagen fibers. In conclusion, smal intestinal submucosa sponge isapotential material used asthe tissue-engineered skinscaffold.