Objective To investigate quercetin's protective effect against oxidative stress in and impact on the biological activity of mouse B10BR melanocytes. Methods B10BR cells were cultured and treated with different concentrations of quercetin followed by additional culture. Then, cell viability was measured by using MTT assay, hydrogen peroxide-induced cell apoptosis by flow cytometry, and cell morphological changes by microscopy. The tyrosinase activity in and melanin synthesis by B10BR cells were measured by dopa oxidation assay and sodium hydroxide (NaOH)-lysis method, respectively. Results After treatment with quercetin of 33.33 μmol/L for 24 hours, the survival rate of B10BR cells reached (94.22 ± 3.36)%, tyrosinase activity (107.15 ± 10.96)%, and melanin content (111.85 ± 9.49)%. A significant difference was observed in tyrosinase activity and melanin content between hydrogen peroxide-induced and 33.33 μmol/L quercetin-treated B10BR cells and those only induced by hydrogen peroxide (both P < 0.01). Flow cytometry revealed that quercetin inhibited hydrogen peroxide-induced apoptosis in melanocytes. Conclusion The protective effect of quercetin against hydrogen peroxide-induced apoptosis in melanocytes may provide a new idea for the treatment of vitiligo.

Objective To express and purify the epitope peptide of human melanin-concentrating hormone receptor 1, and to evaluate its performance in the detection of autoantibodies in vitiligo patients. Methods The target gene encoding the epitope peptide of human melanin-concentrating hormone receptor 1 was synthesized, cloned to prokaryotic expression vector pGEX-4T-2 which was then transferred to E. coli BL21. The protein expression was induced by isopropy-β-D-thiogalactoside (IPTG) and identified with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Blocking ELISA was carried out with membrane proteins extracted from melanocytes as the blocking antigen. The antigenicity of the peptide was detected in sera from 100 patients with progressive vitiligo and 30 healthy human controls. Results The recombinant expression vector was successfully constructed, and the target protein was successfully expressed in E.coli, which was evidenced by SDS-PAGE and Western blot. With the glutathione S-transferase (GST) purification kit, the purity of the recombinant protein reached 100% when the sampling weight was less than 0.625 μg.The binding of the target protein with serum IgG antibodies from vitiligo patients could be blocked by natural membrane antigen of melanocytes. Of the 100 sera from patients with progressive vitiligo, 36 were reactive with the target protein. Conclusions The epitope peptide of human melanin-concentrating hormone receptor 1 has been successfully expressed and purified. The purified protein can bind with serum IgG antibodies from vitiligo patients, and may be applied to the detection of autoantibodies against human melanin-concentrating hormone receptor 1.

OBJECTIVE:To study the effects of Chongcaodihuang(CCDH)syrupus on immune function and antistress ability.METHODS:The experiments were carried out to investigate the effects of CCDH on weight of immune organs,the phagocytization of the monocytes by using the method of carbon particles expurgation,the content of antibody of hemolysin in serum,and time of swimming and hypoxia tolerance in mice.RESULTS:CCDH could enhance weight of immune organs,the phagocytization of the monocytes and increase the content of antibody of hemolysin in serum.It can also delay the time of swimming and strengthen hypoxia tolerance in mice.CONCLUSION:CCDH significantly improve immune function and antistress ability of mice.

Objective To evaluate the histologic changes in the dermis and the changes of the rate of type Ⅲ and type Ⅰ collagen by the radiofrequency device. Methods The effects of radiofrequency current on the dermis were observed. Ten rabbits were treated by radiofrequency, and the histologic change in the dermis were observed by H-E staining and Sirius red staining. Results After RF treatment, the fibers in the dermis appeared more compact and the quantity of the type Ⅲ (red) and type Ⅰ (green) collagen were both increased. The fibers in the dermis appeared more compact and the rate of type Ⅲ and type Ⅰ collagen was increased. It was also found that a significant proliferation of dermal collagen was observed in 8 days after treatment. As time went by, the proliferation of dermal collagen was more pronounced, and the rate of type Ⅲ was increased. Conclusion The radiofrequency current can increase the quantity of collagen in the dermis and increase the rate of type Ⅲ and type Ⅰ collagen, which may be one of the key mechanisms of facial rejuvenation by RF.

Objective To investigate the intracellular signal transduction pathways involved in the protective effect of nicotinic acid against ultraviolet B(UVB)-induced damage in human skin keratinocytes.Methods Cultured human keratinocyte HaCaT cells were divided into several groups to be treated with nicotinic acid,UVB irradiation,LY294002(an inhibitor of Akt),U0126(an inhibitor of extracellular signal-regulated kinase(ERK)1/2),SB203580(an inhibitor of P38)alone or in combination for different durations.Then,Western blot was performed to quantify the phosphorylation levels of the protein kinase B(Akt)/MAPK pathwayassociated proteins including Akt,P38,JNK and ERK1/2,MTT assay to evaluate the activity of HaCaT cells,enzyme-linked immunosorbent assay to determine the levels of endothelin-1(ET-1)and basic fibroblast growth factor(bFGF)in the culture supernatant of HaCaT cells,and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)to evaluate the apoptosis in HaCaT cells.Results As Western blot showed,phosphorylated Akt,P38,JNK and ERK1/2 were markedly activated within 60 minutes after pretreatment with nicotinic acid and irradiation with UVB(all P ＜ 0.01),and the activation was more significant for phosphorylated Akt,P38,and ERK1/2 within 2 hours(all P ＜ 0.01).Nicotinic acid effectively suppressed the UVB-induced cell death and apoptosis in HaCaT cells.The levels of supernatant ET-1 and bFGF were significantly decreased in HaCaT cells treated with the above 3 inhibitors followed by UVB irradiation than in those treated with the inhibitors alone(all P ＜ 0.05),and nicotinic acid pretreatment only reversed the decrease in supernatant bFGF in HaCaT cells treated with SB203580 followed by UVB irradiation.Conclusion The Akt signaling pathway may play a regulatory role in the protection by nicotinic acid against UVB-induced damage in HaCaT cells.

Objective To investigate the effect of nuclear translocation of E2p45 related factor 2 (Nrf2)on the biological activity of melanocytes.Methods Plasmid vectors containing wild-type nrf2 gene (pcDNA-nrf2) and nls-deleted nrf2 gene (pcDNA-nrf2△nls) were constructed.B10BR normal murine melanocytes were classified into three groups,i.e.,untransfected group,wild-type nrf2 group transfected with pcDNA-nrf2,and mutated nrf2 group transfected with pcDNA-nrf2△nls.Each of the above groups were further divided into three subgroups:control subgroup receiving no treatment,hydrogen peroxide (H2O2) subgroup treated with H2O2 of 200 μmol/L for 24 hours,and combined subgroup pretreated with tert-butyl hydroquinone (TBHQ) followed by treatment with H2O2 of 200 μmol/L for 24 hours.Subsequently,methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the proliferative activity of cells,dopa oxidation assay to determine tyrosinase activity,Transwell assay to estimate cell migration ability,Western blot to quantify the expressions of Nrf2 and his tag fusion protein.Results TBHQ significantly enhanced the nuclear expression of Nrf2 in B10BR cells transfected with pcDNA-nrf2 or pcDNA-nrf2△nls (both P ＜ 0.01).No significant difference was observed in tyrosinase activity between untreated wild-type nrf2 group,mutated nrf2 group,and untransfected group (P ＞ 0.05).There was a statistical decrease in tyrosinase activity in the two H2O2-treated transfected groups compared with the untreated transfected groups (both P ＜ 0.05),and the decrease was reversed by TBHQ pretreatment in the wildtype nrf2 group (P ＜ 0.05),but not in the mutated nrf2 group (P ＞ 0.05).Further more,the proliferative activity of B10BR cells experienced no obvious changes in the wild-type nrf2 group (P ＞ 0.05),but was significantly reduced in the untransfected group (P ＜ 0.05) and mutated nrf2 group (P ＜ 0.01) after the H2O2 treatment compared with the corresponding untreated groups.TBHQ could protect the pcDNA-nrf2-transfected B10BR cells,but not pcDNA-nrf2△nls-transfected B10BR cells,from H2O2-induced oxidative damage.Transwell assay showed no significant difference in migration ability among these nine groups (P ＞ 0.05).Conclusions Abnormal nuclear translocation of Nrf2 could affect antioxidant activity of,proliferative activity of and tyrosinase activity in melanocytes.TBHQ may enhance the tyrosinase activity in,proliferative activity and antioxidant activity of melanocytes via activating the nuclear expression of wild type Nrf2.

Bacillus anthracis collagen-like protein(BclA) is a structural component of the exosporium filaments,as well as the immunodominant antigen on the spore surface.The genes encoding BclA proteins were cloned and sequenced from three Bacillus anthracis strains separated from China.It was founded that the BclA proteins of strain A16R and 40048,containing 388 and 322 amino acids,72 and 50 copies of GXX repeat,5 and 3 copies of 21-amino-acid sequence(GPT)_(5)GDTGTT(BclA repeat) respectively,are different from those reported by foreign scholars;while the BclA protein of strain 40022,containing 370 amino acids,66 copies of GXX repeat,and 5 copies of BclA repeat,is identical with that of strain 53169 reported by others.The results are helpful for the molecular typing of B.anthracis strains,and provide a basis for the elucidation of the pathogenesis and immunogenicity of B.anthracis spore.

Anti-Bacterial Agents ; pharmacology ; Humans ; Methicillin ; pharmacology ; Methicillin Resistance ; genetics ; Sequence Homology ; Staphylococcus aureus ; drug effects ; genetics

OBJECTIVETo investigate the oral health status of freshmen of university students and to guide their oral hygiene behaviors.

METHODS6,575 freshmen of Peking University students were investigated in this study according to the criterion issued by World Health Organization (WHO) on the basic methods of oral health investigation and China oral health epidemiology survey protocol. The inspection item included caries, gingivitis, malocclusions and impacted teeth.

RESULTSIn 6,575 freshmen of university students, the prevalence rate of caries, gingivitis, malocclusions and impacted teeth were 35.47%, 60.87%, 19.70% and 24.62%, respectively. There were statistical significance between the prevalence rate of caries, gingivitis, malocclusions and impacted teeth of male and female (chi2=131.94, P<0.001: chi2=216.85, P<0.001; chi2=14.54, P<0.01; chi2=23.56, P<0.001). There were statistical significance between the prevalence rate of caries, gingivitis and impacted teeth of postgraduate and undergraduate (chi2=4.62, P<0.05: chi2=129.56, P<0.001; chi2=178.05, P<0.001), while there was no statistical significance between the prevalence rate of malocclusions of postgraduate and undergraduate (chi2=0.61, P>0.05).

CONCLUSIONThe oral health status of freshmen of university students are not ideal. It is necessary to strengthen the propaganda education of prevention and protect to freshmen of university students.

China ; Dental Caries ; Female ; Health Status ; Humans ; Male ; Malocclusion ; Oral Health ; Oral Hygiene ; Prevalence ; Students ; Universities