Objective:To study the ultrastructural changes of the junctional epithelial after dental preparation. Methods: Junctional epithelium (JE) of left premaxillary teeth was detached by diamond bur in 8 rabbits (group 1) and by surgical knife in another 8 rabbits (group 2). JE of the right teeth without treatment was used as the controls. 4 animals in each group were sacrificed 1 and 2 weeks after operation respectively.Samples were prepared for transmission electron microscope observation.Results: In the two tested groups reattachment was observed 2 weeks after operation,degeneration of mitochondria in JE cells and destruction of basement membrane were observed. No significant difference was observed between group 1 and group 2.Conclusion: Dental preparation may result in ultrastructural changes of JE cells.

Objective To investigate the indications and complications in the treatment of benign and malignant strictures using esophageal stents in order to avoid abusing effects in clinical practice. Methods A series of 20 patients, 12 men, 8 women, aged from 45～72, with esophageal stricutre. There were 3 cases had stricture at the anastomosis site. 4 cases with esophago bronchial fistula. 1 case with esophago mediastinal fistula after surgical operation ten cases used imported stents and another 10 with domestic Nickel Titanium stents. Results Successful stent placement was achieved in all cases. Dysphagia were relieved in most of 20 cases. The fistula vanished in 5 cases of complications with esophago bronchial and esophago mediastinal fistulas. Conclusions The esophageal stent placement is an effective treatment for benign and malignant esphageal strictures. The domestic Nickel Titanium stents is well effective as the imported ones.

Objective To study the survival, migration and distribution of allogeneic marrow stromal cells (MSCs) which were marked with fluorescence agent Hoechst 33342 in vitro and then transplanted into the mice with acute radiation injury, and to explore the hematopoietic reconstitution in allogeneic MSCs transplantation. Methods The bone marrow of murine femoral bone was washed out with DMEM, the cell suspension was gathered and centrifuged twice, and then the MSCs were cultured in vitro, marked with Hoechst 33342 at final concentration of 10?g/ml. 30 minutes later, the MSCs were gathered and transplanted into radiation injured mice via intravenous injection. Each mouse was injected with 2?105 MSCs. The distribution of marked MSCs was observed in heart, liver, spleen, lung and kidney of radiation injured mice at time points of 1w, 2w and 3w after MSCs transplantation. Results After being marked with Hoechst 33342, the nuclei of MSCs were in bright blue color. All mice of MSCs-transplant-group survived until execution, but three mice of Non-MSCs-transplant-group died during three weeks. Only a few marked MSCs were found in heart, liver, lung and kidney in the frozen section at each time point, but a large number of marked MSCs were found on the surface of spleen, and colonies were formed two weeks after introduction of MSCs. Conclusions Transplanted MSCs can not only survive in the irradiation injured mice, but also specifically migrate to the injured site, to participate in the reconstitution of hematopoiesis after acute radiation injury.

Objective To investigate the relationship between the latest WHO criteria of thymic epithelial tumours(TET) and the incidence of MG,Osserman classfication and postoperative prognosis of myasthenia gravis(MG). Methods To analyse the pathological sections of 105 patients with thymoma from 1974 to 2000 with Levine-Rosai's clinicopathological classification,traditional histological classification and WHO classification respectively,and analyse and compare their relevance with the incidence,Osserman classification and postoperative prognosis of MG.Results (1)The cases with benign tumors of type A and type AB were more than those of type B.(2)Type B3 more likely accompanied MG than type A and type AB (P

To observe the morphological changes in hair cell nuclei in guinea pigs following noise exposure, guinea pigs were exposed to 4 kHz narrow band noise at 115 dB SPL for 4h. The cochleae were collected for the examination of the hair cell nuclei 14 days after the noise exposure. A fluorescent dye, Hoechst 33342,a fluorescent dye, was used to label the nuclear DNA and the specimens were examined under a fluorescence microscope for quantitative assessment of hair cell nuclear damage. There were three types of morphological changes in the damaged hair cell nuclei: nuclear swelling, nuclear condensation (karyopyknosis) and nuclear missing. Nuclear swelling was more frequent than nuclear missing. Nuclear condensation was less frequently found. The results suggested that complicated, long term and non synchronous biological processes might be involved in noise induced hair cell damage. A large number of hair cells with swollen nuclei, which might recover afte wards,still could be seen in the cochlea two weeks after noice exposure.

Objective To study the relations between the susceptibility to AIDP and AMAN, two forms of Guillain-Barr? syndrome (GBS), and the frequency of HLA-A, B alleles. Methods A case-control research was done in 31 cases of AIDP, 33 cases of AMAN and 132 health individual controls. DNA was extracted from peripheral blood leukocytes by improved fast saltingout. HLA-A, B antigens were typed by DNA-based technology, PCR-sequence specific primers (PCR-SSP) method. In determination of allelic polymorphism by PCR amplification with SSP, oligonucleotide primers are designed to obtain amplification of specific alleles or groups of alleles. Assignment of alleles is based on the presence or absence of PCR amplified product, which may be detected by agarose gel electrophoresis. Results On research of HLA-A, B alleles polymorphism, it showed that HLA-A33 frequency was increased significantly in AIDP patients [22.6% vs 4.5%,corrected probability (Pc)=0.011]; related risk (RR) was 6.1; HLA-B15, B35 frequencies were increased (51.7% vs 20.8%, Pc =0.015; 34.5% vs 6.9%, Pc=0.000 8); RR was 4.1 and 7.1, respectively. Conclusions There are different distribution of HLA-A, B alleles in AIDP and AMAN, two forms of GBS. AIDP susceptibility is associated with HLA-A33, while AMAN is with HLA-B15, B35.

Objective Cathepsin K (CTSK) played an important role in adipocyte differentiation.The activation of CTSK needs to convey by mannose-6-phosphate receptors (M6PR) in osteoclasts. The aim of the present study was to identify the effects of mannose-6-phosphate (M6P) in adipocyte differentiation and its underlying molecular mechanism. Methods Oil red O staining, accumulation of cytoplasmic triglycerides and glycerine release were used to assess its effects on adipocyte differentiation in the 3T3-L1cell line. The enzyme activity of CTSK was observed by laser confocal microscopy. The proliferation of 3T3-L1 preadipocytes was detected by MTT methods. mRNA expression of M6PR was determined by RTPCR. Results M6P could prevent adipocyte differentiation in a dose-dependent manner as evidenced by absence of triglyceride accumulation and glycerol content. Statistical significance was showed when the concentrations of M6P were 5.0 mmol/L and 8. 0 mmol/L respectively(P ＜0. 05). The mRNA expression of M6PR was detected during the whole process of adipocyte differentiation. With the increase of M6Pconcentration, enzyme activity of CTSK was inhibited in a concentration-dependent manner. MTT method showed that the absorbance at 570 nm of 3T3-L1 preadipocytes was 0. 057 ±0. 091, increased about 62. 9%at 10. 0 mmoL/L compared with the control group (P ＜ 0. 05 ). Conclusion M6P inhibits the terminal differentiation of adipocyte, which may be associated with its effect of blocking CTSK activity by competitive binding with M6PR.

Objective To explore the infections of human cytomegalovirus (HCMV) in chronic hepatitis C patients and the hepatic impairment in chronic hepatitis C patients co-infected with HCMV.Methods HCMV-DNA was determined by fluorescence quantitative-PCR (FQ-PCR) in 95 patients with chronic hepatitis C (observation group) and 95 healthy controls(control group) and HCMV active infections were analyzed.HCV-RNA was determined by FQ-PCR in observation group,and the difference of HCMV-DNA positive rate between high HCV-RNA(＞ 104 copies/ml) and low HCV-RNA(≤ 104 copies/ml) was analyzed.Alanine aminotransferase (ALT),aspartate aminotransferase (AST) were determined by rate method in two groups and the hepatic impairment was analyzed.Results Twenty-five cases with positive HCMV-DNA in observation group,the positive rate was 26.3％(25/95).Five cases with positive HCMV-DNA in control group,the positive rate was 5.3％(5/95).There was significant difference between two groups for HCMV-DNA (x2 =14.29,P ＜0.01).Twenty-one cases with positive HCMV-DNA in 43 cases of high HCV-RNA patients,the positive rate was 48.8％(21/43).Four cases with positive HCMV-DNA in 52 cases of low HCV-RNA patients,the positive rate was 7.7％(4/52).There was significant difference between the two (x2 =19.90,P ＜ 0.01).ALT,AST in observation group was higher than that in control group (P ＜ 0.01).ALT,AST in chronic hepatitis C patients positive for HCMV-DNA was higher than that in chronic hepatitis C patients negative for HCMV-DNA significantly (P ＜ 0.01).Conclusions HCMV in chronic hepatitis C patients becomes active again and co-infects easily.When chronic hepatitis C patients co-infect HCMV actively,hepatic is further injured.

Objective To study the clinical features of hyperkalemic periodic paralysis (hyperKPP) and the relationship with SCN4A gene in a Chinese family Methods The clinical features of 7 patients in a Chinese family with hyperKPP were summarized All 24 exons of SCN4A gene were screened with denaturing high performance liquid chromatography (DHPLC) technology, and then sequence analysis was performed on those with abnormal elution peak Results This family showed typical clinical features of hyperKPP but without myotonia Three mutations were found in exon 13, 23 and 24 respectively Linkage analysis and direct sequencing showed the mutation in exon 24 was a synonymous mutation The mutation in exon 23 was a missense mutation, but proved to be a benign polimophism; the mutation in exon 13 was proved leading to the best known amino acid exchange Thr704Met Conclusion SCN4A gene should be related to hyperKPP, and Thr704Met be responsible for hyperKPP in this Chinese family

Objective To evaluate the feasibility of reconstruction of artificial bladder tissue using the expanded bladder cells seeded onto both sides of a synthetic PLGA polymer and cultured in the nude mice by tissue engineering technique. Methods The urothelial cells and smooth muscle cells were obtained from young rabbits by mechanical isolation and enzyme digestion method. In vitro cultured and expanded smooth muscle cells and urothelial cells were seeded onto the outer and inner surfaces of each polymer. Then, the constructs were implanted into the subcutaneous pockets of athymic mice. At 4 and 8 weeks after implantation, the specimens were harvested and examined macroscopically, histologically, and immunohistochemically. Results The polymer was covered with urothelial cells inside and smooth muscle cells outside. As polymer degradation was in progress, the urothelial cells and the smooth muscle cells kept proliferation and converged. Conclusion Artificial bladder tissue reconstructed by tissue engineering technique has the similar properties to those of the normal bladder wall. This study has laid solid foundation for further studies of tissue engineering bladder.