Gene mutation is known to play an important role in carcinogenesis.There are two types of p53 gene,wild-type and mutant-type.In order to observe the relationship between p53 gene mutation and cutaneous squarnous epithelial ceil tumours,immunohistochemical study was carried out for p53 ex- pression in the epidermis from 29 patients with cutaneous squamous epithelial cell tumouts using a new immunohistochemical technique labelled streptavidin biotin system.The results showed that p53 positive staining was only confined to areas of atypical proliferation of epithelia in 3/6 cases of actinic keratosis. 6/10 cases of Bowen's disease and 8/13 cases of squamous cell carcinoma showed that p53 positive staining was seen throughout the tumour.It is suggested that p53 gene mutation might play an impor- tant role in cutaneous squamous epithlial cell tumour formation.

The cause of sarcoidosis is still unknown. However,the histological similarity between the disorder and tuberculosis suggests that M. tuberculosis might contribute to the pathogenesis of sarcoidosis. In attempting to confirm the relation between M. tuberculosis and sarcoidosis,we used the polymerase chain reaction to detect M. tuberculosis DNA from formalin--fixed,paraffin--embeded skin biopsy specimens of 12 patients with sarcoidosis, M. tuberculosis DNA was found in 4 patients. This finding suggests an aetiological role for M. tuberculosis in sarcoidosis.

In this study we successfully prepared desmoglein 1 and desmoglein 3 DNA probes by incorporation of Dig-dUTP during PCR amplification. Eleetrophoresis analysis showed that Dig labelled probes moved slower on the gel than PCR products not incorporated with Dig due to the enlargement of probe fragment. The results of Dot-blot showed that the prepared probes can be used for RNA analysis, and both probes have high specificity, The results provided basis for the quantitative and qualitative study of desmoglein gene expression in tissues or cells by means of in situ hybridization and Northern hybridization etc.

Objective To evaluate the production and regulation of platelet derived growth factor (PDGF) in the skin. Methods Normal human keratinocytes (NHKs) and human dermal fibroblasts (HDFs) were cultured, PDGF peptides were measured by ELISA and PDGF B chain mRNA was detected by Northern hybridization. Results The results showed that NHKs constitutively produced PDGF molecules, phorbol 12 myristate 13 acetate (PMA) inhibited PDGF production, while 1, 25 dihydroxyvitamin D 3 enhanced its production. TNF alpha, interferon ? and interleukin 1 alpha all failed to affect PDGF production. On the other hand, HDFs produced no PDGF molecule in spite of a low level of PDGF B chain mRNA expression in Northern hybridization, suggestting a post transcriptional blocking of PDGF production in HDFs. Conclusion The results obtained above indicate that epidermal keratinocytes may be the major PDGF generating cells, whereas dermal fibroblasts the PDGF responsive cells in the skin.

Objective To study the expression and regulation of interleukin 15 (IL 15) in epidermal keratinocytes. Methods The expression of IL 15 mRNA in cultured normal human keratinocytes (NHKs) and human squamous cell carcinoma cell line (HSC 5) was analysed, and the effect of dexamethasone on IL 15 mRNA expression was studied by using RT PCR and Northern blotting technique. Results The results showed that both NHKs and HSC 5 expressed IL 15 constitutively. The level of IL 15 mRNA was significantly decreased after the cells were cultured with 10 -6 M dexamethasone. Conclusion It is suggested that keratinocyte derived IL 15 might be involved in the development of certain inflammatory skin diseases.

Objective To study the expression of endothelin 1 (ET 1) mRNA in keratinocytes in patients with vitiligo. Methods Fourteen patients with progressive vitiligo were measured by hybridization in situ. Results Our results showed that the expression of ET 1 mRNA was markedly decreased. Conclusion The results revealed that decreased ET 1 expression may be associated with the pathogenesis of vitiligo. The cause and role of decreasing of ET 1 expression of keratinocyte in vitiligo lesion need to be studied further.

Objective Through isolating the histidine kin ase gene of Aspergillus fumigatus,to detect its role in the invasive aspergillosis.Methods Using degenerate primers for highly conserved regions of his-tidine kinase,RT -PCR was performed with cDNA of Aspergillus fumigatus as a template.The gene expression of it in vitro and in vivo was investig ated by Northern blot.Results A fragment of this gene was cloned fro m Aspergillus fumigatus that is highly homologous to tesA gene of Aspergillus nidulans,which was expressed at high level during invasive infection.Conclusion The results indicate that this gene may attribute to the invasive aspergillosis.

Objective To investigate the correlation between phosphatidylinositol 3 kinase (PI3-kinase) and the pathogenesis of psoriasis. Methods By dot hybridization, in situ hybridization and immunohistochemistry, expression of PI3 kinase was observed in twelve psoriatic and five normal epidermis. Results In psoriatic epidermis, expression of PI3 kinase gene and protein was elevated obviously compared with that of normal skin. Conclusion PI3 kinase may be closely associated with hyperproliferation of psoriatic keratinocytes.

Objective To investigate the significance of Akt in the pathogenesis of psoriasis.Methods Tissue specimens were obtained from involved and uninvolved skin of 30 patients with progressive psoriasis vulgaris and normal skin of 20 human controls.Immunohistochemistry.immunobloting and kinase activity assay were performed to detect the expressions of Akt and phosphorylated Akt as well as Akt activities in these specimens.Immunostaining intensity Was assessed by optical density detection and the results of immunobiot and activity assay by grey scanning.Statistical analyses were performed by variance analysis and student's t test.Results As immunohistochemistry revealed.there was no significant difierence in Akt protein expression among normal epidermis,psoriatic epidermis and uninvolved epidermis(F=0.611,P＞0.05):the level of phosphorylated Akt in psoriatic epidermis was significantly higher than that in normal epidermis and psoriatic uninvolved epidermis(F=19.081.P＜0.01).while no significant difierence was observed between normal epidermis and psoriatic uninvolved epidermis (t=0.624.P＞0.05).Immunoblot showed a significant difierence in phosphorylated Akt(t=237.75.P＜0.01)but not in Akt(t=1.378,P＞0.05)between psoriatic involved epidermis and normal epidermis.In comparison with normal epidermis,the activity of Akt in psoriatic involved epidermis was increased significantly(t=138.44 1.P＜0.0 1).Conclusion The overproliferation of psoriatic keratinocytcs may be associated with increased activation of Akt.

To investigate the freshness, high molecular weight substances, the determination of polypeptide, haemolysis and agglomeration, biological activity of Cervus and Cucumis polypeptide injection; to provide the direction for improving the quality of products for enterprises; furthermore, to provide reference for the revision of the quality standards of Cervus and Cucumis polypeptide injection. Firstly, we investigated the factors affecting the freshness of the injection, including biogenic amines, aflatoxins, the acid value and peroxide value of the melon seeds. The method of dansyl chloride pre-column derivatization-HPLC was used to determine the content of 8 biogenic amines in Cervus and Cucumis polypeptide injection. The method validation results showed good specificity, precision, linearity and recovery rates, which was suitable for the determination of biogenic amines in Cervus and Cucumis polypeptide injection. The results of sample determination showed that relatively higher concentrations of cadaverine were detected in the products from company B. The results of aflatoxins, acid value and peroxide value showed that the melon seeds from some companies had rancidity, mildew and other problems, indicating that the quality standards of multi-component biochemical drugs containing animal- and plant-derived components should be controlled in terms of freshness. Secondly, the methods for the determination of high molecular weight substances and polypeptides in the quality standard were improved. Tricine-SDS-PAGE electrophoresis was used instead of gel chromatography to determine the high molecular weight substances, which improved the accuracy of determination. The kits were used instead of folin-phenol for the determination of peptide content, which is easy to operate, specific and suitable for high-throughput sample determination. Finally, the haemolysis, agglomeration, and biological activity of Cervus and Cucumis polypeptide injection were studied. The results showed that no haemolysis and agglomeration were found in all samples, and the inhibitory effect of samples on THP-1 proliferation in vitro from different companies was different to some extent. In conclusion, the optimized quality standard is more suitable for the detection of Cervus and Cucumis polypeptide injection, and can lay the foundation for improving the safety of multi-component biochemical drugs.