Objective To estimate the effect of different doses of ultraviolet (UV) radiation on the proliferation of and apoptosis in kertatinocytes,as well as on the expression of p53,matrix metalloproteinase-2 (MMP2) and-9 (MMP9) in actinic keratosis (AK) lesions and normal human skin.Methods Tissue specimens were obtained from the lesions of 20 patients with AK and sun-exposed normal skin of 20 healthy human subjects,and subjected to an air-exposed culture.Each of the specimens was divided into 4 areas to remain untreated (control area) or be irradiated with UV of 5,10 and 20 J/cm2 (irradiated areas) for 4 consecutive days.After another 24-hour culture,the tissue cultures were collected followed by the evaluation of apoptosis in and proliferation of keratinocytes by using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Ki-67 staining,and determination of mRNA and protein expressions of p53,MMP2 and MMP9 by using real time PCR and immunohistochemistry respectively.Results A statistical increase was observed in the percentage of apoptotic cells in the normal skin irradiated with UV of 10 and 20 J/cm2 (46.8％ ± 2.1％ and 56.7％± 2.4％,both P ＜ 0.05) and in the AK lesions irradiated with UV of 20 J/cm2 (43.5％ ± 1.5％,P ＜ 0.05)compared with the corresponding unirradiated tissues.The normal skin showed a higher percentage of apoptotic cells than the lesional skin after irradiation with UV of 10 and 20 J/cm2 (both P ＜ 0.05).The percentage of Ki67-positive cells was significantly decreased in the normal skin after irradiation with UV of 20 J/cm2 (3.34％ ±0.76％,P ＜ 0.05),but experienced no statistical changes in the lesional skin after different doses of UV irradiation (all P ＞ 0.05).There was a statistical elevation in the expression of p53 mRNA (5 J/cm2:1.106 ± 0.025,10 J/cm2: 1.259 ± 0.045,20 J/cm2:1.425 ± 0.053,all P ＜ 0.05) and protein(10 J/cm2:0.1169 ± 0.0032,20 J/cm2:0.1454 ± 0.0047,both P＜ 0.05) in the normal skin,but a statistical reduction in the expression of p53 mRNA(10 J/cm2.0.611 ± 0.050,20 J/cm2:0.578 ± 0.070,both P ＜ 0.05) and protein (20 J/cm2:0.0404 ± 0.0027,P＜ 0.05) in the lesional skin after irradiation compared with the corresponding unirradiated skin tissues.Further more,a statistical increment was observed in MMP2 mRNA and protein expression in normal skin irradiated with UV of 10 J/cm2 (1.086 ± 0.013,0.0843 ± 0.0024,respectively,both P ＜ 0.05) and 20 J/cm2 (1.417 ± 0.036,0.1236 ±0.0042,respectively,both P ＜ 0.05) and in lesional skin irradiated with UV of 20 J/cm2 (1.296 ± 0.028,0.0744± 0.0032,respectively,both P ＜ 0.05),as well as in MMP9 mRNA and protein expression in normal skin irradiated with UV of 20 J/cm2 (1.395 ± 0.026,0.3065 ± 0.0162,respectively,both P ＜ 0.05) and in lesional skin irradiated with UV of 10 J/cm2 (1.298 ± 0.035,0.0992 ± 0.0053,respectively,both P ＜ 0.05) and 20 J/cm2(1.286 ± 0.032,0.1010 ± 0.0063,respectively,both P ＜ 0.05) compared with the corresponding unirradiated tissues.Conclusion Ultraviolet may accelerate the progression of AK by down-regulating p53 expression but up-regulating MMP2 and MMP9 expression.

Objective To evaluate the efficacy and safety of hydroxychloroquine combined with butyli flufenamatum ointment and other drugs for the treatment of polymorphous light eruption (PLE).Methods A total of 48 patients with PLE were randomly and equally classified into group 1 and group 2.Both groups took hydroxychloroquine 200 mg twice a day and loratadine 10 mg per day for the initial 4 weeks,then took hydroxychloroquine 100 mg twice a day alone for another 4 weeks.Group 1 also topically applied butyli flufenamatum ointment twice a day during the 8 weeks,while group 2 applied mometasone furoate cream twice a day for the first 2 weeks followed by butyli flufenamatum ointment twice a day for another 6 weeks.Each treatment cycle lasted 2 weeks,and both groups received 4 cycles of treatment.Patients were evaluated for the response rate at the end of each cycle,and for the total symptom score and erythema score before and after the 8-week treatment.Statistical analysis was carried out using t test,chi-square test,Fisher's exact test and repeated-measures analysis of variance with the SPSS17.0 software.Results On day 14,28,42 and 56,the total score improved in 0,3,12 and 19 patients in group 1 respectively,and in 1,4,12 and 20 patients in group 2 respectively;the erythema score improved in 1,5,13 and 18 patients in group 1 respectively,and in 0,5,11 and 17 patients in group 2 respectively.No significant difference was observed between the two groups in response rates at any of the above four time points (P ＞ 0.05).Both the total score and erythema score significantly decreased after the 8-week treatment in both groups compared with the pretreatment scores (both P ＜ 0.05).No serious adverse reaction was observed in either of the two groups.Conclusions Hydroxychloroquine combined with loratadine and butyli flufenamatum ointment shows high efficacy and safety for the treatment of PLE.Topical butyli flufenamatum ointment is highly effective for the treatment of PLE,especially for PLE cases mainly presenting with erythema.

Objective To compare the clinical efficacy of cold snare endoscopic mucosal resection(CS-EMR)with conventional endoscopic mucosal resection(EMR)in the treatment of＜20 mm colorectal laterally spreading tumor(CLST).Methods A total of 248 CLST patients undergoing endoscopic resection treated in the First People's Hospital of Huzhou from January 2020 to June 2022 were selected and divided into EMR group and CS-EMR group according to random number table method,with 124 cases in each group.The general data,focal features,surgical indicators and complication rate of two groups were statistically compared.Results There were no significant differences in en bloc resection rate,complete resection rate and postoperative recurrence rate between two groups(P＞0.05).The operation time and hospital stay in CS-EMR group were significantly shorter than those in EMR group,the number of titanium clips and hospitalization costs were significantly lower than those in EMR group,and the incidence of intraoperative bleeding,delayed bleeding and delayed perforation were significantly lower than those in EMR group(P＜0.05).Conclusion In treatment of CLST with a maximum diameter of＜20mm,CS-EMR not only retains the advantages of fewer surgery-related complications,but also has similar therapeutic effect as EMR,and reduces the cost burden of patients,which is worthy of clinical reference and promotion.