Objective To examine the distribution of HA in monocytes and expression of CD44 and ICAM-1 on the monocytes and effects of HA and HA receptors on adhesion and migration of the monocytes. Methods Canine peripheral blood monocytes were isolated by non-continuous density centrifugation with percoll solution.HA on the cell surface,intracellular HA,CD44 and ICAM-l of the monocytes were labeled with immunofluorescence.Effects of HA on the cell surface,substrate HA and free HA on adhesion and migration of the monocytes were examined by digesting HA on the cell surface with HAase,coating the bottom of the dishes and the membrane of the cell culture inserts with HA and adding HA into the medium.Regulating effects of HA receptors on adhesion and migration of the monocytes were investigated after blockade of the receptors. Results There was HA on the surface and in the cytoplasm of the monocytes.CD44 and ICAM-1 were expressed on the monocytes.The adhered and migrated monocytes decreased after HA on the cell surface was digested with HAase.The numbers of the adhered and migrated monocytes were greater when the cells were incubated on HA-coated dishes and membranes of the cell culture inserts.The adhered and migrated monocytes decreased after HA was added into the medium.When CD44 was blocked with antibody,the adhered and migrated monocytes decreased.There were not significant changes in the numbers of the adhered and migrated monocytes after ICAM-1 was blocked with antibody.Conclusion There is HA on the surface and in the cytoplasm of monocytes.HA on the cell surface is essential for adhesion and migration of the monocytes.HA substrate promotes adhesion and migration of the monocytes,while free HA reduces adhesion and migration of the cells.CD44 mediates HA-induced adhesion and migration of the monocytes.

Objective To investigate apoptosis and bcl-2 expression of dust cells in human bronchopulmonary lymph nodes and murine peritoneal macrophages treated with carbon particles and study the relation of apoptosis of dust-laden macrophages and structural changes of the lymph nodes. Methods Distribution of dust particles, apoptotic cells and structural changes of the lymph nodes were viewed on paraffin sections and ultrathin sections. Apoptosis and bcl-2 expression of dust cells in human bronchopulmonary lymph nodes and macrophages treated with carbon particles were observed with TUNEL staining and bcl-2 antibody labeling. Results In the bronchopulmonary lymph nodes of the adult group, dust particles were deposited significantly in macrophages, the lymphatic tissue decreased, collagen fibres and density of blood vessels increased. In ultrathin section, the nucleus condensed and contained vacuoles. There were TUNEL-positive cells and bcl-2 labeling positive cells in dust cells of the lymph nodes and macrophages 24*!h after phagocytizing carbon particles. Bcl-2 was expressed strongly in the active macrophages decomposing dust particles or carbon particles. Conclusion Deposition of dust particles induces apoptosis and overexpression of antiapoptotic gene bcl-2 of macrophages in human bronchopulmonary lymph nodes. Structural changes of the bronchopulmonary lymph nodes in adult may relate to apoptosis of dust-laden macrophages.

Objective To report the preliminary results of treatment of fracture nonunion at the distal femur and the proximal tibia with Less Invasive Stabilization System (LISS). Methods From February 2003 to August 2004, LISS fixation and bone grafting were employed to treat 5 cases of fracture nonunion at the distal femur and 4 cases of fracture nonunion at the proximal tibia. The nonunion had resulted from failure of internal fixation in 7 cases, failure of external fixation in 1 and infection in 1. The history of nonunion lasted from 10 to 111 months (mean 29m). Results All the 9 patients were followed up for an average of 8 (6 to 16) months only to reveal solid bone union in all the fractures, with a mean healing time of 4.7 months (ranging from 4 to 6 months). No loosening or breakage of the implants occurred in this series. Conclusion Due to its advanced design, LISS can be used to treat effectively fracture nonunion at the distal femur and the proximal tibia.