Objective To investigate the formation and elimination of photoproduct in epidermal cells from BALB/c mice irradiated with ultroviolet B, and to observe the interference by baicalin in it. Methods BALB/c mice were randomized into 6 groups, I.e., blank control group receiving no exposure or protection, baicalin group receiving protection with baicalin, acetone group receiving acetone pretreatment, UVB group receiving UVB irradiation but no protection, UVB + baicalin group receiving UVB irradiation and protection with baicalin, UVB + acetone group receiving acetone pretreatment and UVB irradiation. Baicalin was applied at 1 mg/cm2 on the back of mice for 3 days in baicalin group and UVB + baicalin group. Twenty hours after the last application, UVB irradiation of 180 mJ/cm2 was given to mice in UVB group and UVB + baicalin group. Skin specimens were obtained from the tested sites at 1, 24, and 48 hours, respectively, after the irradiation. Cyclobutane pyrimidine dimers (CPD) was detected in the specimens with immunohistochemical staining and Southwestern dot blotting. Results CPD was observed only in irradiated mice. The relative content of CPD in epidermal cells 1, 24 and 48 hours after the irradiation was (100±5.22)%, (75.34±8.22)% and (42.11±3.24)%, respectively, in UVB group, (81.45±5.22)%, (32.14±6.33)% and ( 5.21±3.15 )% respectively, in UVB+baicalin group, ( 106±8.21 )%, (70.23±4.13 )% and (41.22±4.21)%, respectively, in UVB + acetone group. A significant difference was observed in the relative content of CPD between UVB group and UVB + baicalin group at 1, 24 and 48 hours after the irradiation (P<0.05, 0.01, 0.01, respectively). Conclusions Taken together, these results suggest that topical baicalin application mitigates DNA photo-damage. Baicalin is therefore a promising protective substance against UVB radiation.

A typical smooth-form lipopolysaccharide (LPS) isolated from Salmonella abortus equi was fractionated into a S (smooth)-and a R (rough)-fraction and their serological and biological properties were investigated. It was shown that S- fraction expressed an O-antigenicity while R-fraction predominately a Rb-antigenicity. The R-fraction was endowed with higher bioactivities than the S-fraction in lethal toxicity, local Shwartzman reaction and pyrogenicity. Both S-and R-fractions were active in inducing mitogenicity to murine spleen cells. A reconstituted LPS preparation with fractionated S-fraction and a trace amount of R-fraction (1% of the original preparation) exhibited a same extent of lethal toxicity as that of the original one. Antr-Ra and -Rb antiserum with a liter of 1?4096 showed a .highly effective protection against the lethal challenge of LPS, indicating that the R-fraction in the natural LPS preparations plays a critical role to the lethality of LPS.

Superoxide anion releasing from activated murine macrophages stimulated with recombinant human interferon-? (IFN-?), tumour necrosis factor-? (TNF-?) and bacterial lipopolysaccharidc were studied. The results showed that both of the cytokines enhanced superoxide anion release in a dose and time - dependent manner, but lipopolysaccharide had no such an effect as compared with IFN-? and TNF-?. It was also shown that O2- generation from macrophages was highly enhanced after primed with IFN-? or TNF-? for 24 hours. It was concluded from these data that cytokines released from macrophages and lymphocytes during inflammatory reactions could promote O2- generation which may play a crucial role in destruction or kill of intracellular pathogenic bacteria, and tumour cells.

Objective:To assess regional occult metastases on clinical negative neck node [cN0] in patients with buccal mucosal squamous cell carcinoma. Methods:69 patients (31males and 38 females ) with cN0 buccal mucosa squamous cell carcinoma who underwent a lymph node dissection (at the Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing University Medical School) between 1992 and 2004, were retrospectively reviewed. The patients ranged in age from 31 to 79 years with a mean age of 58.2 years. All patients received radical neck dissection(RND), functional neck dissection (FND) or supraomohyoid neck dissection (SOND). Results:The incidence of occult metastases for patients with cN0 buccal mucosa squamous cell carcinoma was 14.49% (10/69).The distribution of the positive nodes was as follows: Level I,10.14%(7/69); Level II, 5.80% (4/69); Level III, 2.90%(2/69). The occult metastasis rate for patients with T1, T2, T3 and T4 was 9.52% (2/21), 15.38%(6/39), 25.00%(1/4), and 20.00%(1/5), respectively. In patients with well differentiated carcinoma,the occult metastasis rate was 14.89%(7/47); moderate differentiated,10.00%(2/20); and poorly differentiated,50.00%(1/2). Conclusion:The assessment of regional occult metastases for patients with cN0 buccal mucosa squamous cell carcinoma may play an important role in deciding treatment approaches of neck.

Objective To observe the changes of microRNA141 expression in photodamaged skin of mice irradiated with ultraviolet B (UVB).Methods Eighteen C57/BL6 mice were equally divided into six groups to receive single irradiation on the hair-removed back with UVB of 0,30,60,90,180 and 270 mJ/cm2 respectively.Skin specimens were obtained from the irradiated sites 24 hours after the irradiation and subjected to paraffin embedding followed by hematoxylin-eosin (HE) staining for the observation of histopathological changes.Real-time quantitative PCR was performed to determine the miRNA141 expression in skin specimens,immunohistochemical staining (IHC) to quantify the expression of phosphatase and tensin homolog deleted on chromosome ten (PTEN) protein.The TargetScan database was employed for the prediction of miRNA141 targets,and Gostat analysis for functional clustering.Data were processed using SPSS version 13.0 software,and intergroup comparisons were done by analysis of variance.Results The relative expression level of miRNA141 in skin tissue was 2.1354 ± 0.4289,2.4333 ± 0.2517,2.9328 ± 0.3126,3.4125 ± 0.3606,4.5667 ± 0.4014 and 6.7428 ± 0.5158 in mice irradiated with UVB of 0,30,60,90,180 and 270 mJ/cm2 respectively.There was a positive correlation between the expression level of miRNA141 and radiation dose (r =0.992,P ＜ 0.01).Gostat analysis showed that the targets of miRNA141 were mainly related to transcription regulation and signaling transduction.Moreover,PTEN expression gradually decreased with the increase in radiation dose.Conclusions miRNA141 may be involved in UVB-induced photodamage and inflammatory response,and PTEN may play a regulatory role in this process.

Objective To detect the expression of translationally controlled tumor protein (TCTP) in squamous cell carcinoma (SCC) tissue and cell lines A431 and SCL-1,and to evaluate the effect of TCTP on apoptosis in and proliferation of SCC cells.Methods An immunohistochemical method was used to measure the expression of TCTP in tissue specimens from 65 patients with SCC.Western blot was performed to detect the expression of TCTP in A431 and SCL-1 cells.Three small interference RNAs (siRNAs) targeting the TPT1 gene were designed,synthesized,and transfected into A431 cells.Then,reverse transcription (RT)-PCR and Western blot were conducted to measure the expression of TPT1 mRNA and TCTP,respectively,methyl thiazolyl tetrazolium (MTT) assay and flow cytometry were carried out to detect cell proliferation and apoptosis,respectively.Results TCTP was overexpressed in SCC tissue specimens,and the expression level was positively correlated with the histologic grading of SCC (P ＜ 0.05).Western blot showed that TCTP was expressed in both A431 and SCL-1 cells,and the expression was relatively high in A431 cells.The transfection efficiency of siRNAs varied from 90％ to 95％.A decrease in the expression of TPT1 mRNA and TCTP was induced by the siRNAs in A375 cells (all P ＜ 0.05).Conclusion The downregulation of TCTP expression may increase the apoptosis in and suppress the proliferation of A431 cells.

Obective To evaluate the effects of dihydrotestosterone (DHT) on the expression of sterol regulatory element-binding protein-1c (SREBP-1c) in human HaCaT keratinocytes.Methods HaCaT cells were cultured in vitro and classified into 4 groups,i.e.,control group receiving no treatment,DIIT group treated with 3 different concentrations (10,100,1000 nmol/L) of DHT,LY294002 plus DHT group treated with DHT of 100 nmol/L after 40-minute pretreatment with the PI3K inhibitor LY294002 of 50 μmol/L,PD98059 plus DHT group treated with DHT of 100 nmol/L after 40-minute pretreatment with the MEK inhibitor PD98059 of 50 μmol/L.After another 24-hour culture,real time PCR and Western blot were carried out to detect the expression of SREBP-1c mRNA and protein in HaCaT cells,respectively.Western blot was also performed to determine the phosphorylation levels of protein kinase B (AKT),extracellular signal-regulated kinase (ERK),p38 mitogen activated protein kinase and c-Jun N-terminal kinase (JNK) in the HaCaT cells.Results DHT could enhance the expression of SREBP-1c mRNA and protein in HaCaT cells in a concentration-dependent manner,and induce the phosphorylation of AKT and ERK,but not that of P38 or JNK.The expressions of SREBP-1c mRNA and protein were significantly decreased in HaCaT cells treated with LY294002 plus DHT (7.4780 ± 1.2638 vs.21.6170 ± 2.2759,t =9.406,P ＜ 0.05; 0.7113 + 0.0313 vs.2.2577 + 0.0601,t =39.498,P ＜ 0.05),but experienced no statistical changes in those treated with PD98059 and DHT(both P ＞ 0.05),compared with those treated with DHT only.Conclusion DHT can induce the expression of SREBP-1c mRNA and protein in HaCaT cells,likely via the PI3K/AKT signaling pathway.

ObjectiveTo observe the effect of topical sulfotanshinone sodium(STS) on sebaceous hyperplasia in animal models. MethodsThe sebaceous gland spots of adult male Syrian hamster flank organ served as the animal model. Sulfotanshinone sodium(0.5％) was applied to sebaceous gland spots in the right flank organ thrice daily, while those in the left were treated with normal saline as control. Parameters were examinedbefore, 10 days, 20 days and 30 days after the beginning of the topical treatment. A vernier caliper was utilized to measure the size of sebaceous gland spots, hematoxylin and eosin(HE) staining to observe the structure of sebaceous glands, immunohistochemistry to determine the expression of proliferating cell nuclear antigen (PCNA) in sebaceous gland cells, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay to assess the apoptosis of sebaceous gland cells. ResultsAt the baseline, no significant difference was observed in the size of sebaceous gland spots or in the proliferation and apoptosis of sebaceous gland cells between the two sides of flank organ(all P ＞ 0.05), with tightly arranged intact sebaceous glands. Compared with normal saline, sulfotanshinone sodium significantly reduced the size of sebaceous gland spots(P ＜ 0.05). Sebaceous glands were loosely arranged with decreased quantity and volume and obviously atrophic on day 30 in the right flank organ of hamsters. A decrease was observed in the expression of PCNA in sulfotanshinone sodium treated sebaceous gland cells compared with those treated with normal saline(P ＜ 0.01 ), which was more striking on day 10 and 20(both P ＜ 0.005). Sulfotanshinone sodium also induced an enhancement of apoptosis in sebaceous gland cells (P ＜ 0.01 ), which was more apparent on day 20 (P ＜ 0.005 ), and the degree of apoptosis was higher in the central area than in the peripheral area of sebaceous glands. ConclusionSulfotanshinone sodium can reduce the size and alter the microstructure of sebaceous gland spots, and inhibit the hyperplasia of sebaceous glands.

Aim To investigate the roles of p53-dependent signaling pathways in the process of ginsenoside Rg1 protection against 8-methoxypsoralen(8-MOP) and subsequent ultraviolet A(UVA) irradiation induced photoaging model in human dermal fibroblasts(HDFs).Methods Photoaging model was established by 8-MOP/UVA in skin HDFs.Flow cytometry, enzyme cytochemistry, immunofluorescence and Western blot were employed.Results Pretreatment with ginsenoside Rg1 could significantly reduce the amount of UVA-generated 8-oxo-dG and relieve the photoaging representation.Compared with 8-MOP/UVA treatment group, pretreatment with Ginsenoside Rg1 could decrease the expression of SA β-galatosides(SA-β-Gal), and down-regulate the level of senescence associated proteins(p16 and p21).Conclusions Ginsenoside Rg1 has prominent dose-dependent antagonism on senescence of skin HDFs induced by 8-MOP/UVA, and its mechanism may be due to its antioxidation which reduces the production of photoproducts to protect telomere against abnormal shortening.

Objective To investigate the expression changes of microRNA 146a (miRNA146a) in UVBdamaged mouse skin. Methods C57/BL6 mice were divided into dose groups to be irradiated on the back with UVB of 30, 60, 90, 180, 270 mJ/cm2 respectively for 24 hours, and time groups irradiated with UVB of 180 mJ/cm2 for 1, 12, 24 and 48 hours respectively. The mice received no irradiation served as the control. Skin samples were subsequently obtained from the irradiated sites of mice and subjected to real-time fluorescent PCR for the detection of miRNA146a expression as well as immunohistochemical staining (IHC) for the detection of STAT3. Results The expression levels of miRNA146a were 0.01158 ± 0.00098, 0.01083 ± 0.00104,0.00872 ± 0.00031, 0.00851 ± 0.00033, 0.00810 ± 0.00057 and 0.00770 ± 0.00031 in the unirradiated control mice and mice irradiated with UVB of 30, 60, 90, 180, 270 mJ/cm2 for 24 hours, respectively, 0.00730 ±0.00036, 0.00805 ± 0.00035, 0.00810 ± 0.00057 and 0.00837 ± 0.00039 in mice irradiated with UVB of 180mJ/cm2 for 1, 12, 24 and 48 hours, respectively. IHC suggested an intensive expression of phosphorylated STAT3 in mice irradiated with a high dose UVB. Conclusions miRNA146a may play an essential role in the mechanism of UVB-induced photodamge, which is mainly correlated with the negative regulation of inflammatory reaction likely mediated by the JAK/STAT3 signal transduction pathway.