Objective:To explore the application effect of a new type of simulated dermatologic surgical mold based on 3D printing in standardized residency training of dermatology.Methods:In this study, 35 residents in Department of Dermatology, The Second Affiliated Hospital of Guangzhou Medical University from January 2018 to May 2019 were randomly divided into two groups: a new mold group based on 3D printing ( n=18) and a traditional mold group ( n=17). Two groups of residents were examined by dermatologic biopsy on the mold, and the effect of teaching was evaluated by questionnaire survey. SPSS 22.0 was used for data analysis, and the measurement data was expressed by (means ± standard deviation). The comparison between the new mold group and the traditional mold group was made by two independent samples t test. Results:The scores of dermatologic biopsy examination of residents in the new mold group were higher than those in the traditional mold group, and the differences were statistically significant ( P<0.01); and the scores of the questionnaires for the teaching effect of the new mold group were higher than those of the traditional mold group, and the differences were statistically significant ( P<0.01). Conclusion:The new type of simulated dermatologic surgical mold based on 3D printing, which has been successfully applied in the practical training of residents, lays a solid foundation for the actual clinical operation and significantly improves the teaching effect, providing a broad application prospect.

Psoriasis is considered as an inflammatory disease driven by T cells, and its pathogenesis is closely related to the imbalance of intestinal bacteria flora. It has been reported that Bacteroides fragilis could play an anti-inflammatory role by regulating the expression of cytokines in T cells. To date, there is no report using B. fragilis to treat psoriasis. In this study, we explored the therapeutic effect of B. fragilis BF839 on psoriasis. We selected 27 psoriasis patients who were treated in the Second Affiliated Hospital of Guangzhou Medical University from April to October 2019. The patients were given B. fragilis BF839 orally for 12 weeks while maintaining the original treatment. The psoriasis area and severity index (PASI) score was evaluated before and after the treatment. The rate of drug withdrawal and reduction after 12 weeks of treatment were calculated. Our results showed that the rate of 12-week trial completion was 96.3% (26/27). We used PASIN to define the proportion of people whose PASI score decreased more than or equal to N% after treatment. At 12 weeks, PASI30, PASI50, and PASI75 were 65.4%, 42.3%, and 19.2%, respectively. The PASI score was 9.1±5.9 and 5.8±4.9 before and after 12 weeks of treatment respectively, and the difference was statistically significant (P<0.01). The effective rate of the visual analog scale (VAS) score was 42.3% at 12 weeks, and the VAS score was 2.9±2.2 and 2.3±2.1 before and after 12 weeks of treatment, respectively, which had no statistically significant difference (P>0.05). The adverse reaction rate of patients was 3.8% (1/26) within 12 weeks of treatment, including 1 case of constipation, and the rate of drug withdrawal and reduction was 60.0%. The above results suggest that B. fragilis BF839 may be functional on the treatment of psoriasis by reducing the PASI score and the drug usage rate with few side effect, which deserves further study.
Anti-Inflammatory Agents ; Bacteroides fragilis ; Cytokines ; Humans ; Psoriasis/drug therapy* ; Severity of Illness Index ; Treatment Outcome

Objective:To investigate the interaction of platelet factor 4(PF4)with tumor necrosis factor-α(TNF-α)in the pathoge-nesis of chronic periodontitis(Ⅲ-C).Methods:22 patients with chronic periodontitis(Ⅲ-C)and 22 subjects with periodontal health were recruited.Before and after periodontal treatment,the concentration of PF4 and TNF-α in gingival crevicular fluid(GCF)and ser-um,the amount of PF4 released by platelets after lipopolysaccharide(LPS)stimulated peripheral blood platelets were measured by ELISA.Flow cytometry was used to calculate the number of platelets in GCF before and after treatment.Results:The concentrations of PF4 and TNF-α in the GCF and serum of the patients were higher than those in the periodontal healthy group(P＜0.05).After treat-ment,the concentrations of PF4 and TNF-α in the GCF were significantly lower than those before treatment(P＜0.05),and the con-centrations of PF4 and TNF-α in the serum were unchanged(P＞0.05).After LPS stimulation of the platelets in blood before and after treatment,the concentration of PF4 released by the platelets was much higher in the patients than that in the healthy controls(P＜0.01),and the concentration was significantly lower after periodontal treatment than before treatment(P＜0.01).The number of CD41/CD61 double positive platelets and CD45 negative cells in GCF before periodontal treatment were 85 times and 87 times higher than those in periodontal healthy subjects,respectively(P＜0.01).Conclusion:PF4 and TNF-α have synergistic effect in the patho-genesis of chronic periodontitis.