Tooth bleaching has become a routine way of treating tooth staining. It is necessary to teach tooth bleaching in undergraduate education of Stomatology. The possibility of teaching bleaching was explored in our school and the teaching effects were assessed by questionnaires to undergraduate students of Stomatology in 2005 and 2006 degree after class. The outcomes indicated that a teaching mode of “3+3+2” made a positive effect on the teaching of tooth bleaching, combining with multimedia teaching,problem-based learning and bilingual teaching. The present article summed up the experience of teaching tooth whitening in undergraduate education of Stomatology and gave some advice for improving the quality of teaching.

Melanoma is a highly malignant immunogenic tumor. Although immunotherapy represented by immune checkpoint inhibitors can markedly improve the survival rate of patients with metastatic melanoma, nearly half of patients are still tolerant or resistant to immunotherapy, with high incidence of immune-related adverse reactions. This review focuses on the key difficulties in tolerance, resistance and immune-related adverse reactions to current melanoma immunotherapy, and summarizes corresponding strategies and research advances. By intervening in the immunosuppressive microenvironment in melanoma, screening precise biomarkers, and optimizing immunotherapy-based combination strategies, the problem of tolerance and resistance to immunotherapy can be solved. Moreover, the combination of traditional immunotherapy and nanotechnology can also greatly reduce the occurrence of immune-related adverse reactions. In the future, more extensive and in-depth research on the tumor immune microenvironment will help to explore the best immunotherapy regimens for melanoma.

Objective To investigate the clinical effects of different doses of propranolol in treatment of infantile mixed and deep hemangioma,and to provid theoretical and experimental evidence for the treatment of hemangioma. Methods The selected 62 patients with mixed and deep hemangioma were divided randomly into low dose (1.5mg·kg-1 ·d-1 )and high dose (3.0 mg·kg-1 ·d-1 )of propranolol groups,3 times a day,6 months as a course,the changes in hemangioma size and the incidence of adverse reactions were recorded.Results The efficacy was evaluated using Achauer system.The total effective rate was 80.65% in low dose of propranolol group and 93.55% in high dose of propranolol group,including 6 cases of class Ⅰ (poor),9 cases of class Ⅱ (moderate), 11 cases of classⅢ (good),and 5 cases of class Ⅳ (excellent)in low dose propranolol group;while 2 cases of class Ⅰ (poor),4 cases of class Ⅱ (moderate),10 cases of class Ⅲ (good)and 15 cases of Ⅳ (excellent)in high dose of propranolol group.The efficacy in high dose of proprandol group was significantly better than that in low dose of proprandol group (P<0.05),there were no significant differences in the efficacies between different sites and different types (P>0.05)and there was no significant difference in the incidence of adverse reaction between two groups (P>0.05).Conclusion The efficacy of oral 3.0 mg·kg-1 ·d-1 propranolol in treatment of infantile mixed and deep hemangioma is increased significantly, and there is no significant adverse reactions after increasing doses.Therefore,high dose of propranolol should be recommended in order to improve the therapeutic effect.

Objective: To explore the impact of antibiotic exposure on human fertility, so as to provide the reference for related research on risk factors and prevention of infertility. Methods: Publications pertaining to antibiotic exposure and human fertility were retrived in CNKI, Wanfang Data, VIP, PubMed, Embase and Web of Science from inception to March 2024. Two reviewers independently conducted literature screening, data extraction, and quality assessment. A qualitative analysis was performed to investigate the effect of antibiotic exposure on human fertility. Results: A total of 11 623 articles were retrieved, and 31 of them were finally included. Among them, 19 were quasi-experimental studies (4 high-quality and 15 medium-quality), 6 were observational studies (5 high-quality and 1 medium-quality), and 6 were randomized controlled trials (RCTs) with high risks of implementation bias and measurement bias. Sixteen quasi-experimental studies and five RCTs found that the use of sensitive antibiotics such as doxycycline for the treatment of reproductive system infections improved female pregnancy rates or male semen quality. Two quasi-experimental studies and one RCT suggested that antibiotics (such as sirolimus or sulfasalazine) used to treat other systemic diseases might cause adverse effects on the reproductive system. Four observational studies indicated that exposure to antibiotics such as sulfonamides, macrolides, and tetracyclines increased the risk of infertility or prostate cancer. Two observational studies found a dual effect of antibiotics on infertility. Conclusions Antibiotic exposure appears to have either beneficial or harmful effects on fertility, depending on the antibiotic types, doses, and indication. However, these studies have limitations such as small sample size, selection bias, and the inability to achieve randomization and blind methods. Further research with optimized designs is necessary to explore the relationship between antibiotic exposure and fertility.

Objective To study the impact of establishment of lipopolysaccharide ( LPS )-induced rat model of chronic obstructive pulmonary disease (COPD)on the function of multidrug resistance-associated protein 1(MRP1)in the rat bronchial epithelium .Methods Using intratracheal instillation of LPS to establish COPD rat model .8-week old healthy male Wistar rats were divided into 3 groups (10 rats in each group ):(1) Normal control;(2) Modeling for 14 days after LPS instillation;(3) Modeling for 28 days after LPS instillation.Pulmonary function and the concentration of phenol red in bronchoalveolar lavage fluid ( BALF) and plasma were measured .The ratio of phenol red concentration in BALF/plasma was used as an index of the MRP 1 function in the rat bronchial epithelium and the expression of MRP 1 in the bronchial epi-thelium was also observed by immunohistochemistry .Results Compared with the normal group , the pulmonary functions of the rats in the model groups were significantly reduced along with the modeling progress .After intravenous administration of phenol red, the ratio of phenol red concentration in BALF/plasma was gradually reduced , and the expression of MRP1 in the bronchial epithelium was significantly decreased .Conclusions COPD rat model can be established by intratracheal LPS instillation, and the function of MRP1 in bronchial epithelium was gradually reduced along with the modeling progress .

Objective To observe the effects of ursolic acid (UA) on the activation of nicotinamide adenine dinucleotide phosphate oxidase (NOX) and the downstream signaling pathways in platelet derived growth factor (PDGF) activated rat hepatic stellate cell (HSC-T6).Methods Rat HSC-T6 cells were divided into blank control group (no treatment),UA control group (50 μmol/L UA),PDGF group (10 μg/L PDGF),UA intervention group (50 μmol/L UA + 10 μg/L PDGF),diphenyleneiodonium intervention(DPI) group (20 μmol/L DPI+ 10 μg/L PDGF),SB203580 (p38 mitogen-activated protein kirase(p38MAPK) inhibitor) intervention group (10 μmol/L SB203580 + 10 μg/LPDGF),LY294002 (phosphatidylinositop 3 kinase(PI3K) inhibitor) intervention group (10 μmol/L LY294002 + 10 μg/L PDGF) and rosup positive control group (5 μg/mL rosup).Except rosup positive control group,the expression of type Ⅰ collagen at mRNA level of each group was detected by fluorescence quantitavepolymerase chain reaction (RT-PCR).The expression of membrane protein p47phox (except rosup positive control group),PI3K(except rosup positive control group and SB203580 intervention group),p-protein kinase B (p-AKT,except rosup positive control group and SB203580 intervention group) and phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK,except rosup positive control group and LY294002 intervention group) were tested by Western blot.Except SB203580 intervention group and LY294002 intervention group,the fluorescence intensity in the cells of each group was analyzed with active oxygen detection kit and fluorescence microplate reader.Single factor analysis of variance and LSD test were performed for comparison between groups.Results Type Ⅰ collagen at the mRNA level of PDGF group (3.74±0.32) was higher than that of blank control group (1.00±0.00) ; Type Ⅰ collagen at the mRNA level of UA group (0.21 ±0.02) was lower than that of blank control group,UA intervention group (1.02 ± 0.12),DPI intervention group (1.09±0.21),SB203580 intervention group (1.18± 0.27),and LY294002 intervention group (1.15 ± 0.26) were all lower than PDGF group,and the differences were statistically significant (t =15.667,-4.501,-15.553,-15.154,-14.642 and -14.813,all P＜0.05).p47phox at the protein expression level of PDGF group (1.98±0.53) was higher than that of blank control group (1.00±0.00) ; that of UA group (0.48±0.10) was lower than blank control group; those of UA intervention group (0.95 ± 0.26),DPI intervention group (0.99 ± 0.28),SB203580 intervention group (0.93±0.31),and LY294002 intervention group (1.07±0.19) were all lower than PDGF group (t=4.209,-2.234,4.424,-4.252,-4.510 and-3.909,all P＜0.05).The protein expression level of PI3K of PDGF group (2.27±0.46) was higher than that of blank control group (1.00±0.00); that of UA intervention group (0.14 ± 0.07) was lower than PDGF group and blank control group; that of UA group (0.14±0.07) was lower than blank control group; those of DPI intervention group (0.53±0.25) and LY294002 intervention group (0.35±0.14) were all lower than PDGFgroup (t 6.205,8.208,-2.003,4.202,-8.502 and-9.831,all P＜0.05).The protein expression level of p-Akt of PDGF group (2.54±0.49) was higher than that of blank control group (1.00± 0.00); those of UA intervention group (0.74± 0.20),DPI intervention group (0.94 ± 0.37) and LY294002 intervention group (1.17±0.41) were all lower than PDGF group; that of UA group (0.59± 0.15) was lower than blank control group (t=5.927,-6.928,-6.158,-5.273 and-1.578,all P＜ 0.05).The protein expression level of p-p38MAPK of PDGF group (1.98±0.35) was higher than that of blank control group (1.00±0.00); those of UA intervention group (0.68±0.28),DPI intervention group (0.63±0.27) and SB203580 intervention group (0.67 ± 0.29) was all lower than PDGF group; that of UAgroup (0.28±0.13) was lower than blank control group (t=4.897,-6.479,-6.727,-6.529 and-3.561,all P＜0.05).The level of active oxygen of PDGF group (105.57±7.51) was higher than that of blank control group (69.60±8.63) ; those of UA intervention group (64.56±9.11),DPI intervention group (65.75 ± 6.62) was lower than PDGF group,UA group (29.84 ±3.19) was lower than blank control group (t=6.368,-7.288,-7.071 and-7.255,all P＜0.05).Conclusion UA could inhibit membrane displacement of NOX subunit p47phox and reduce active oxygen production in PDGF induced rat HSC-T6 cells,and then block phosphorylation of PI3K Akt,p 38MAPK signal pathways and inhibited the expression of type Ⅰ collagen at mRNA level.

Objective To investigate the proportion changes of the CD4 + CD25 + T cells and CD8 + CD28 - T cells in the peripheral blood of gastric cancer patients. Methods The proportions of CD4 + CD25 + T cells and CD8 + CD28 - T cells in the peripheral blood of gastric cancer patients were determined by flow cytometry. 30 patients with gastric cancer and 30 patients with chronic gastritis were enrolled in this study. Results Compared with the chronic gastritis controls, the proportion of the CD4 + CD25 + T cells in the peripheral blood of patients with gastric cancer (8.7%±1.3%) was not significantly changed. But the proportion of the CD8 + CD28 - T cell in the peripheral blood of patients with gastric cancer (30.3%±3.3%) was significantly higher than that of control group (20.3%±2.7%), P<0.05. There was no significant association between the proportions of T regulatory cells and the lymphomatic metastasis of gastric cancer. No relation was found between the proportions of T regulatory cells and pathological types of gastric cancer. Conclusion CD8 + CD28 - T ceils in peripheral blood may be of some value in the progression of gastric cancer.

Objective To investigate the effects of an electromagnetic field on the extra-cellularly regulated kinase(ERK)signalling pathway and to determine the impact of electromagnetic activation on osteogenic proliferation and differentiation in rat bone marrow mesenchymal stem cells.Methods Rat bone marrow mesenchymal stem cells were isolated and cultured in vitro.The third-passage cells were divided into 4 groups(Control,PD98059,EMF and EMF+PD98059).Western blotting Was used to detect the activation of the ERK signal pathway after exposure to an electromagnetic field.MTT assay Was used to determine the activation of proliferation in the celb in the different groups.The cells' alkaline phosphatase activities were also detected. Results (1)The ERK signal pathway in these rat bone marrow mesenchymal stem cells was activated after exposure to a 15 Hz.1 mT,sine wave form electromagnetic field for 5 min.Activation remained high for at least 1 h.PD98059 can effectively block the activation of the ERK signal pathway.(2)Cell proliferation was promoted after exposure to the electromagnetic field,and this effect could be significantly inhibited by PD98059.(3)Alkaline phosphatase was significantly elevated in these bone marrow mesenchymal stem cells after exposure to the electromagnetic field.The activation in the EMF+PD98059 group Was slightly greater than in the EMF group.Conclusion Electromagnetic fields of 15 Hz and 1 mT can activate the ERK signal pathway and alter proliferation and osteogenic differentiation in the bone marrow mesenchymal stem cells of rats.

Objective To investigate the bacterial distribution and drug resistance in urinary tract infection from Sichuan Provin‐cial Antimicrobial Resistant Investigation Net during 2011-2012 .Methods The distribution and drug resistance data of pathogens isolated from urine specimens of urinary tract infection cases were collected from the members of Sichuan Provincial Antimicrobial Resistant Investigation Net ,and the results were counted and analyzed .Results There were 54 hospitals enrolling in the investiga‐tion .A total of 12 420 pathogenic strains were isolated from urinary tract infection in the survey .The top 5 predominant bacteria were Escherichia coli(46 .5% ) ,Excrement enterococcus (7 .0% ) ,K lebsiella pneumoniae (5 .8% ) ,Dung enterococcus (5 .7% ) and Pseudomonas aeruginosa(3 .7% ) .The resistant rates of Escherichia coli ,K lebsiella pneumoniae and Pseudomonas aeruginosa to imipenem were 16 .0% ,16 .7% and 16 .0% ,and to levofloxacin were 55 .2% ,28 .2% and 27 .7% ,respectively .The resistant rates of Excrement enterococcus and Dung enterococcus to vancomycin were 4 .1% and 1 .4% respectively .Conclusion Escherichiacoli and Enterococcus are still the predominant organism in urinary tract infection cases .Clinical treatment should refer to the results of drug sensitive test .

Objective To explore the effect of a new prone position for general anesthesia.Methods 50 patients in the group were made a retrospective study:All the 50 patients needed prone position surgeries under general anesthesia.After awake flexible fiberoptic intubation,with the anesthesia of thyrocricoid puncturing the intra-trachea surface,has been taken,patients lied in the prone position according to their own comfort with the guide of medical staff,which was followed by anesthesia induction and the operation.The SBP,DBP,HR and RPP were recor-ded at different point of time after patients entered the operation room.Results 33 cases of 50 patients completed the whole process successfully and the indexes at the time of the intubation had no significant difference with those at basic state(all P >0.05).17 operations suffered discomfort.The SBP,DBP,HR and RPP in these patients were (159.2 ±25.9)mmHg,(97.2 ±11.6)mmHg,(98.2 ±9)beats per minute and (16 028 ±6 725)respectively, which were higher than those at basic state(t =2.698,2.802,5.720,8.905,all P <0.05).After applications of small dose sedative,these patients were successfully tracheal intubated.The SBP,DBP,HR and RPP were (144.0 ± 18.5)mmHg,(83.0 ±10.5)mmHg,(89.3 ±10.0)beats per minute and (12 658 ±5 521)respectively at the time of the second intubation,which had no significant difference with those at basic state(all P >0.05).Conclusion It is technically simple and easy to operate,the way that patients waiting for prone position surgeries lie in the prone position by themselves with awake flexible fiberoptic intubation lightens the workload of medical staff and reduces complications of the intubation,which is optional in clinical situations.