Objective To investigate the cause of excessive collagen accumulation in keloid tissue. Methods The ultrastructure of keloid was observed by transmission electron microscope. New formed collagen in keloid was localized with ABC immunohistochemical staining. Type I procollagen mRNA level in keloid tissue was determined by dot blot hybridization using human pro-al (I)collagenspecific cDNA probe. Results Numerous fibroblasts with abundant, well developed rough endoplasmic reticulum were exhibited in the ultrastructure of keloid. The type I procollagen mRNA levels were significantly increased in kreloid tissue. Immunohistochemical staining showed increased expression of new formed, type I procollagen in keloid tissue. Conclusion the fibroblasts are activated in collagen synthesis in active keloid. The enhanced collagen synthesis by fibroblasts is a critical factor leading to the overabundant collagen accumulation in keloid.

This paper discusses the problems, clinical application and limitations of argon-helium cryosurgical scalpel and liquid nitrogen cryosurgical scalpel. The feasibility of self-absorption liquid-CO2 cryosurgical scalpel is analyzed. The result shows that self-absorption liquid-CO2 cryosurgical scalpel can be applied to cryosurgery.

Objective To investigate whether the sort of drugs causing drug eruptions complicated with drug-induced liver dysfunction are the same as those causing drug eruptions. Methods Sixty-one cases of drug eruption complicated with drug-induced liver dysfunction in 261 cases confirmed as drug eruptions from January 1998 to March 2003 were analyzed retrospectively. Results The major hepatotoxic drugs in these cases were antivirus drugs (60%, 9/15), antituberculosis drugs (66.67%, 8/12), zyloric (55.56%, 5/9), and some traditional Chinese medicines (31.58%, 6/19). Conclusion The sort of drugs causing drug eruptions complicated with drug-induced liver dysfunction are the same as those causing drug eruptions, which should be taken into consideration in clinical medication.

Objective To establish a simple and practical method for isolating and purifying nucleosomes. Methods Nuclei were isolated from chicken erythrocytes, and then digested with staphylococcal nuclease. After centrifugation, the supernatant of digestion was separated and centrifugated on sucrose gradients. Results Nucleosomes with good stability were isolated properly by gradient centrifugation. Conclusion This method for the isolation and purification of nucleosomes is simple and effective, which might contribute to the further researches of the roles of nucleosomes in the pathogenesis of systemic lupus erythematosus.

Objective To study the survival and melanogenic potential of human melanocytes reversibly immortalized via SV40T antigen gene and Cre/loxP system in Guinea pigs. Methods The supernatants of retrovirus vector Cre-ERT2 were used to infect melanocytes which had been successfully transfected by SV40TAg gene (MCT), then the expression of Cre recombinase was induced with tamoxifen in infected cells; subsequently, the surviving cells, which were named as MCTC, were subjected to expansion culture. Guinea pigs were utilized to establish animal models of vitiligo, then MCTC and primary melanocytes were transplanted respectively into the animal models. The repigmentation at the transplanted area was observed with naked eyes successively until 3 months after the transplantation when tissue samples were obtained from implanted area and nonimplanted area of guinea pigs and subjected to Masson-Fontana silver stain and Hematoxylin-eosin stain for the analysis of melanocyte distribution and melanin deposition in epidermis. Results Repigmentation started 4 weeks after the transplantation, and dark or brown patches, which ranged in size from 0.5 to 1 cm, were observed in the implanted area 3 months after the transplantation. The repigmentation rate was of no significant difference between pigs transplanted with MCTC and those with primary melanocytes (82.5% vs 76.7%, P > 0.05). Pathological examination revealed melanin deposition in the basal layer of epidermis and some hair follicles in transplanted area. Conclusions SV40T antigen gene combined with Cre/loxP site-specific recombinase system can induce the reversible immortalization of human melanocytes, and the immortalized melanocytes have a favorable profile of biological safety and similarity in survival rate and melanogenic potential to primary melanocytes.

Objective To investigate the therapeutic efficacy of HPV16 E7 peptide pulsed dendritic cells (DCs) in recurrent condyloma acuminate (CA). Methods A total of 32 cases of recurrent CA (more than 3 times) were divided into the treatment group and the control group. Patients (11 cases, HPV16 +and HLA A2 +) in the treatment group received treatment with DCs, while the other 21 cases in the control group were treated with interferon. A follow up of 6 months was conducted in all patients. The pathological lesions, the peripheral T cell subpopulations of the patients, and the therapeutic efficacy before and after treatment were observed. Results The size of the lesions became smaller or disappeared in the treatment group. The infiltrated lymphocytes increased, but the koilocytotic cells decreased in the lesions. No significant change in the peripheral T cell subpopulations was found before and after therapy. The recurrence rates in the treatment group and the control group were 18.2% and 61.9%, respectively. Conclusion The therapy by E7 peptide pulsed dendritic cells can improve the local immune status in the skin and reduce the recurrence rate significantly in patients with recurrent CA.

Objective　To analyze the clinicopathological features of angiolymphoid hyperplasia with eosinophilia (ALHE). Methods　The pathological specimens of 7 cases of ALHE collected in our department from 1950 to 1999 were sectioned, stained and observed. Results　There were 3 pathological characteristics in ALHE: ①massive hyperplasia of capillaries in the dermis; ②the endothelial cells proliferated and swelled, projecting into vascular cavity like tombstones; ③mixed infiltration of lymphocytes and eosinocytes in the vessels. Conclusion　ALHE is a disease with local benign proliferated vessels, whose etiology and pathogenesis is still unknown. It is necessary to grasp the pathological changes of ALHE to distinguish it from other diseases.

Objective　To investigate the role of cytotoxic T lymphocyte associated molecule-4Ig(CTLA-4Ig) in the prevention of C57BL/6 mice autoimmune hepatitis. Methods　The C57BL/6 mice were intraperitoneally immunized with C57BL/6 mice liver-specific protein in complete Freund's adjuvant. At the same time CTLA-4Ig were given to observe the pathologic alteration of C57BL/6 mice liver. Results　With the increase of time of immunization, the results in the treatment group were similar to those of the control group; but inflammatory cell infiltration, hepatic cell swelling, focal necrosis and severe hepatocyte damage were found in the pathologic model group. There was a significant difference between the pathologic model group and control one. Conclusion　Autoimmune hepatitis of C57BL/6 mice can be effectively prevented by CTLA-4Ig.

Objective To investigate the biological activities of a conditioned medium for human dermal papilla. Methods Culture medium of the lower passage human dermal papilla cells was collected as the conditioned medium. The growth pattern and the growth curve of the higher passage human dermal papilla cells cultured with conditioned medium were observed in vitro. And the morphology of the co-culture of the higher passage human dermal papilla cells and the lower passage human dermal papilla cells was observed. Results The higher passage human dermal papilla cells, which was cultured with conditioned medium from the lower passage human dermal papilla cells, showed aggregative growth pattern. And the growth curve of the higher passage human dermal papilla cells was much better than that in the control groups (P

Objective To detect the expression and function of cysteinyl leukotriene receptors (CysLTRs)in keratinocytes.Methods Human keratinocytes were isolated from the tissue of foreskin by digestion with dispase Ⅱ and trypsin,and subjected to primary culture.By using confocal laser scanning microscopy and reverse transcriptase PCR,the localization and expression of CysLTRs were studied in kemtinocytes.respectively.Some primarily cultured keratinocytes were pretreated with leukotriene D4 (30 nmoi/L),MK571(300 nmol/L),and BAYu9773 for 5 minutes followed by the detection of intmcellular calcium level using the Ca2+ indicator dye Fura-2/AM as well as cell proliferation bv MTT assay.Results The expressions of CysLTR1 and CysLTR2 were observed in cultured keratinocytes,and they were mainly located on cell membrane,partly in cytoplasm and nuclei.Compared with non.stimulated cells,a significant increase Was noted in the expression of CysLTRs,especially in the nuclei of keratinocytes stimulated by LTD4(P＜0.05),together with an elevation in intracellular calcium level(42.27±3.00 mmol/L,P＜0.01)and acceleration in cell proliferation (P＜0.01).However,both MK571 and BAYu9773 could completely block the effect of LTD4 on intmcellular calcium level and cell proliferation.and there was no significant difference in the blocking effect between MK571 and BAYu9773.Conclusions Functional CysLTRs are expressed in human keratinocytes.and they carl increase the intracellular calcium level in,and cell proliferation of,keratinocytes.