Objective To investigate the effect of mixed-skin grafting with autologous microskin and allogenetic acellular dermal matrix microskin on wound healing in rats,and to make a further study on the related mechanism.Methods Wistar rats were served as a allogenetic acellular dermal matrix donor rats,and SD rats as acceptors with mould of full thickness skin defects on their back.The ninety SD rats were divided into 5 groups with 18 rats in each group.Group 1 was transplanted with autologous microskin,and group 2 with allogenetic acellular dermal matrix microskin.Groups 3,4 and 5 were grafted with mixed-skin ratio between autologous microskin and allogenetic acellular dermal matrix microskin 1 ∶ 1,1 ∶ 0.5 and 1 ∶ 0.25,repectively.The rate of wound healing was measured,wound samples collected,hematoxylin and eosin stain carried out,fibronectin (FN) and laminin (LN)detected,and intergroup comparison made,respectively,2,3 and 4 weeks after skin grafting.Results The wound healing rates and FN and LN expression of mixed-skin grafting groups were higher than those of the group with autologous microskin grafting.The group of 1 ∶ 0.25 obviously increased (P＜0.05 or P＜0.01).Conclusions The wound healing rate with mixed-skin grafting is higher than that with autologous microskin grafting.The best effect is achieved when the skin ratio between autologous microskin and allogenetic acellular dermal matrix microskin is 1 ∶ 0.25.It is possibly due to the increase of FN and LN on wound skin surface.

BACKGROUND: Type Ⅱ collagen has been used as the carrier for chondrocyte transplantation in animal models, but whether type Ⅱ collagen may cause arthritis or mediate cytotoxicity remains unknown.OBJECTIVE: To detect the cellular immune functions of the New Zealand rabbits immunized by porcine type Ⅱ collagen.DESIGN: An exploratory comparative study based on the observations.SETTING: An institute of trauma surgery of a municipal hospital.MATERIALS: The study was conducted in the Institute of Trauma Surgery,Guangzhou Red Cross Hospital from August 1999 to February 2000. Six New Zealand rabbits, whose body mass ranged from 2.0 kg to 3.0 kg, were chosen of either gender.METHODS: The rabbits were immunized by porcine type Ⅱ collagen for 60days, during which the plasma was regularly taken for detection of type Ⅱ collagen antibody. On the 60th day, the peripheral blood as well as the spleens and lymph nodes were taken to separate the lymphocytes, which were subjected to secondary stimulation with type Ⅱ collagen in vitro to observe the reactive cell proliferation. The lymphocytes were randomly divided into two groups, and the first group was treated with phytohemagglutinin(PHA) of different concentrations to serve as the positive control, in which non-specific immunity was examined; The second group was treated with type Ⅱ collagen of different concentrations for examining specific immunity.peripheral blood lymphocytes of normal and immunized rabbits.RESULTS: On the 21st day, the titer of the antibody presented the first peak, and 40 days after the re-injection of the antigen the second peak appeared, which maintained for 20 days and then gradually descended. The lymphocytes of the normal rabbits proliferated in response to PHA stimulation but not to the first stimulation with the type Ⅱ collagen. The lymphocytes of the immunized rabbits exhibited significant proliferation upon stimulations with both PHA and type Ⅱ collagen. At the concentration of 25 mg/L, type Ⅱ collagen stimulation was sufficient to induce lymphocyte proliferation, the peak of which occurred when the collagen concentration reached 50 mg/L.CONCLUSION: Xenogenic type Ⅱ collagen at an adequate concentration may induce the increase of the type Ⅱ collagen antibody in immunized rabbits and proliferation of lymphocytes of the spleens and peripheral blood to cause cellular immune reaction and even immunological arthritis in relation to the transplantation.

Objective To study the prevalence situation of chronic diseases among teachers from some middle and primary schools in Chongqing City.Methods The physical examination data of 6969 teachers in 52 middle and primary schools in a district of Chongqing major city were collected.The survey data of overweight,obesity,hyperlipidemia,osteoporosis,fatty liver and hyperuricemia were statistically analyzed.Results The total morbidity rates of overweight,obesity,hyperlipidemia,osteoporosis,fatty liver and hyperuricemia were 31.3 ％,7.5 ％,35.1％,34.7 ％,22.4 ％ and 22.2 ％ respectively.The incidence rates of above diseases had difference among the age periods of ≤44 year old,＞44 ＜60 years old and ≥60 year old (P＜0.05).The incidence rate was significantly increased with age increase (P＜0.05).The incidence rate of osteoporosis in females was higher than that in males(P＜ 0.01);while the incidence rate of fatty liver and hyperuricemia in males were higher that in females (P＜0.01).Conclusion The incidence of chronic diseases among teachers in middle and primary schools is worth attention.Therefore it is necessary to carry out the health education aiming at the teacher population characteristics,strengthen their heath management and behavior intervention for increasing their health level.

To detect the cellular immunity state of New Zealand white rabbit immunized by pig type II collagen. The New Zealand white rabbit was immunized by type II collagen for sixty days. The plasma was collected at a regular interval and the anti-type II collagen antibodies were examined. At the sixtieth day, the peripheral circular lymphocytes and the lymphocytes separated from spleen cells of rabbit and lymph nodes were collected and were stimulated by type II collagen in vivo again. The regulation of reactive cellular proliferation caused by the stimulation was detected. The experiment samples were divided into two groups. The first group was the positive control group by adding different concentrations of PHA and the non-specific immunity was assayed. The different concentrations of type II collagen were added to the second group and the specific immunity was assayed. The lymphocytes of normal rabbits showed proliferation by PHA stimulation but no proliferation by the first stimulation of type II collagen. Obvious proliferation due to the stimulation of both PHA and type II collagen in the immunized rabbit were observed. It shows that certain concentration of heterogeneous collagen may cause an increase of anti-type II collagen antibody in immunized rabbit and may cause a proliferation of lymphocytes in rabbit spleen and peripheral blood. The heterogeneous type II collagen causes cellular immunity in vivo.
Animals ; Cell Division ; drug effects ; Collagen Type II ; administration & dosage ; immunology ; Cytotoxicity, Immunologic ; Female ; Histocompatibility Antigens ; Lymphocytes ; cytology ; immunology ; Male ; Rabbits ; Spleen ; cytology ; Swine ; Transplantation, Heterologous