BACKGROUND:Based on variational principle and weighting technology of three-dimensional finite element method, human teeth with a complex morphology can be modeled, which helps to understand the stress distribution of dental hard tissue and prosthesis during the dynamic repair process. OBJECTIVE:To comprehensively analyze the three-dimensional finite element studies concerning biomechanics of dental prostheses, focusing on the effects of metal crown, porcelain thickness, root canal preparation and fil ing on the tooth stress. METHODS:A computer-based search of PubMed (1993-04/2012-09), China Academic Journal Network Publishing Database (2001-2008), and VIP (2001-2008) was performed by the first author to retrieve articles concerning the effects of metal crown, porcelain thickness, root canal preparation and fil ing on the tooth stress. The keywords were“porcelain-fused-to-metal, finite element method, stress analysis, root canal”in English and Chinese. Articles with repetitive contents or meta-analysis were ruled out. Then 40 articles were suitable for further analysis.RESULTS AND CONCLUSION:Finite element method has important significance to establish high-fidelity and high-accuracy models in oral medicine, thereby providing effective biomechanical information for the root canal treatment and post-treatment repair. Scholars continue to explore the stress distribution of dental prostheses during chewing. This review summarizes the stress changes of post and core crowns, supporting reference for further research. Three-dimensional finite element method can be used to build nonlinear three-dimensional finite element models with anisotropic biomechanical characteristics, and can gradual yimprove the transition from static analysis to a dynamic analysis, truly achieving accurate simulation of oral biology and dental morphology as wel as chewing function of the teeth.

Objective To study the concurrence of congenital ptosis and hypospadias and the relationship between the two. Methods The incidence rate and degree of ptosis were recorded for 254 cases of hypospadias. Results The morbidity of ptosis in hypospadias cases was 4.72％.The posterior hypospadias group had a higher ptosis rate than the anterior and middle hypospadias groups,P ＜ 0.05. While there was no statistical difference of severe ptosis morbidity rates between these two groups. Conclusions Congenital ptosis is a common concurrent anomaly of hypospadias outside the urogenital system.The severity of hypospadias is relevant with the morbidity of ptosis but not with the degree of ptosis.Hypospadias and ptosis may share common pathogenic or susceptive factors.

This study is to explore the amelioration of piperine on chronic acute combining stress rat with depression-like behavior, visceral sensitivity, and its effect on the expression of serotonin (5-HT) and synaptophysin. Forty two SD rats were divided into seven groups: blank group, model group, piperine (12.5, 25, 50 and 100 mgkg-1, ig) and imipramine (10 mgkg-1, ip) groups. The rat model of irritable bowel syndrome was established by chronic acute combining stress, and then to evaluate depression-like behavior and visceral sensitivity. The expressions of 5-HT and synaptophysin in the hippocampus and colon were determined by high performance liquid chromatography (HPLC) and Western blotting, respectively. The duration of immobility of IBS rat in the forced swimming test had been significantly increased, the sucrose consumption of IBS rat had been reduced and visceral sensitivity was obviously elevated in the IBS model group as compared with those in the normal control group (P<0.05, P<0.01). As compared with those in the normal control group, the expression of 5-HT significantly decreased, 5-HIAA/5-HT ratio significantly increased in the hippocampus of IBS model group (P<0.05), but opposite presentations were noted in the colon (P<0.05). As compared with that in the normal control group, the synaptophysin expression in the hippocampus decreased significantly but obviously increased in the colon (P<0.05). Piperine improved the behavior of IBS rats, and reversed the levels of 5-HT and 5-HIAA, and 5-HIAA/5-HT proportion in the hippocampus and colon (P<0.05); besides, they significantly reverse the synaptophysin level in the hippocampus and colon (P<0.05). The presence of depression and visceral sensitivity had been changed in IBS rats, with abnormal expression of 5-HT and synaptophysin in the brain-gut system. Piperine can ameliorate the changes of the behavior and regulation of serotonin and synaptophysin expression in IBS rat model.

Objective To evaluate the diagnostic value of treponema pallidum particle agglutination (TPPA) and toludine red unheated serum test (TRUST) for the therapeutic effects of early syphilis.Methods Syphilis patients visited the Dermatological Department of Beijing Tongren Hospital, Capital Medical University from January 2012 to October 2016 were recruited, including 189 patients with early syphilis and 39 patients without clinical symptoms but with risky behavior within 3 months.Serum samples were tested by TPPA and TRUST respectively before treatment and at month 3, 6, 12 after treatment.Comparison between groups was done by χ2 test.Results Serum TPPA results of 228 patients with early syphilis prior to the treatment and within 12 months after treatment were all positive.Before treatment, TRUST tests results of 225 patients were positive, and 156 patients turned negative after 12 months of treatment with the negative conversion rate of 69.3%.The TRUST titer ≤1∶4 before treatment was defined as low-titer group, and ≥1∶8 before treatment was defined as high-titer group.There were 93 patients in the low-titer group, including 3 patients with negative results, and 90 patients with titer 1∶1-1∶4.There were 135 patients in the high-titer group.Twenty-seven patients achieved TRUST negative conversion after 3 months of treatment, among which 19.35%(18/93) with the negative conversion rate in the low-titer group and 6.67%(9/135) in the high-titer group.The difference between the two groups was statistically significant (χ2=7.10, P<0.01).Sixty-two patients converted into negative results of TRUST assay after 6 months of treatment, including 36.56%(34/93) in the low-titer group and 11.85%(16/135) in the high-titer group whose titer of 1∶1-1∶4, and 6.45%(6/93) in the low-titer group and 4.44%(6/135) in the high-titer group whose titer ≥1∶8 turned negative.The difference between the two groups was statistically significant (χ2=17.10, P<0.01).There were 67 patients converted negative detected by TRUST assay after 12 months of treatment, including 23.66%(22/93) in the low-titer group with titer of 1∶1-1∶4 and 14.81%(20/135) in the high titer group, and 1.08%(1/93) in the low-titer group and 17.78%(24/135) in the high-titer group whose titer ≥1∶8 were turned negative.The difference between the two groups was not statistically significant (χ2=1.51, P>0.05).Conclusion Serological tests combined with clinical signs can accurately diagnose early syphilis and evaluate the therapeutic effects.

Objective To investigate the situation of drug resistance and nosocomial infection of multi-drug resistant bacteria (MDR),guidance for clinical rational use of antibiotics.Methods A total of 1521 strains of MDR was isolated from January 2015 to December in Beijing Tongren Hospital,using matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification of bacteria,VITEK-2 Compact and Kirby Bauer (KB) method for drug sensitivity test.Results In 1 521 strains of MDR,Acinetobacter Baumanii were 589 strains (38.7％),nosocomial infection rate were 16.6％;350 strains of Escherichia coli (23.0％),nosocomial infection rate were 9.0％;249 strains of Staphylococcus aureus (16.4％),nosocomial infection rate were 2.7％;171 strains of Klebsiella pneumoniae (11.2％),nosocomial infection rate were 14.3％;150 strains of pseudomonas aeruginosa (9.9％),nosocomial infection rate were 64.7％;12 strains of Enterococcus faecium (0.8％),nosocomial infection rate were 16.7％.MDR Acinetobacter Baumanii,MDR Pseudomonas aeruginosa,extended-spectrumβ-lactamase (ESBL) + Escherichia coli and ESBL + Klebsiella pneumoniae resistance rate to Imipenem were 100％,91.5％,0.6％ and 55.6％.Conclusions MDR pseudomonas aeruginosa (MDR-PAE),MDR acinetobacter baumanii (MDR-AB) and ESBL + Klebsiella pneumoniae were highly resistant,and the nosocomial infection rate were higher.

Objective To detect the antibiotic resistance of four kinds of gram-negative bacilli strains against seven antibiotics and to analyze the differences in antibiotic resistance between the strains isolated in intensive care unit (ICU) and common wards.Methods This study involved 3 238 gram-negative bacilli strains isolated in Beijing Tongren Hospital from January to December 2016.Of all strains, 46.6% were isolated in ICU (severe group) and 53.4% were isolated in common wards (general group).Resistance of these strains to seven kinds of antibiotics was detected and the differences between the two groups were analyzed.Results Antibiotic resistance rates of Pseudomonas aeruginosa strains to ceftriaxone, cefepime and imipenem were 41.7%, 41.2% and 39.5% in severe group and 20.9%, 21.7% and 17.1% in general group.Moreover, the differences between the two groups were all statistically significant (χ2Cefatriaxone=56.72, P<0.01;χ2Cefepime=49.12, P<0.01;χ2Imipenem=69.81, P<0.01).Antibiotic resistance rates of Klebsiella pneumoniae strains to imipenem was 17.2% in severe group and 8.8% in general group, and the difference between the two groups was statistically significant (χ2Imipenem=11.48, P<0.01).Resistance rates of Escherichia coli strains to ceftriaxone and cefepime were 72.9% and 35.8% in severe group and 44.7% and 13.3% in general group, and the differences between the two groups were statistically significant (χ2Ceftriaxone=40.13, P<0.01;χ2Cefepime=41.61, P<0.01).More than 60% of Acinetobacter baumanii strains whether they were isolated in ICU or in common wards were resistant to all the seven antibiotics, and there were no significant differences between the two groups.Conclusion Gram-negative bacilli strains isolated in ICU have higher resistance rates than those isolated in common wards and therefore antibiotics should be used differently.Regular monitoring of drug resistance should be strengthened to provide references for empirical clinical medication.

Objective To evaluate the clinical effect of clitoroplasty with preservation of the glans clitoris and the dorsal neurovascular pedicle in patients with clitoral hypertrophy. Methods From July 2003 to June 2009, cunnus feminization operations with preservation of the glans clitoris and the dorsal neurovascular pedicle and labioplasty were performed on 8 patients with female pseudohermaphroditism. Results All 8 cases were primary healing. The shaping glans of clitoris was completely viable with satisfactory size, location, contour and touching sensitivity, and the cunnuses presented the appearances of female external genital organs. Conclusions Clitoroplasty with preservation of the glans clitoris and the dorsal neurovascular can improve the appearance of clitoris and labia, preserving the functions of sensation and erection, reconstruting a new clitoris which is aesthetically appealing and functional, and it is suitable for various kinds of cunnus feminization operations.

Objective To investigate the correlation of the type of hypospadias and external genital system malformations. Methods From Jan 2000 to Oct 2009, the data of 632 patients diagnosed with hypospadias was analyzed retrospectively. The proportion of all types of hypospadias and the frequency of external genital system malformations were statistically analyzed. Results Among all cases, 12.6% exhibited mild hypospadias, 22. 8% moderate, 43. 2% severe and 21.4% had extremely severe hypospadias. One hundred and eighty-four cases with external genital system malformations were classified into penoscrotal transposition, cryptorchidism, hydrocele of tunica vaginalis,concealed penis and pseudovagina. The probability was about 24.8% (157 cases) of 632 patients with hypospadias. There was significant difference and a positive correlation among the type of hypospadias with total malformations, penoscrotal transposition, cryptorchidism. Conclusions In this patient cohort, moderate and severe hypospadias accounted for the majority of hypospadias. Penoscrotal transposition was the most frequent external genital system malformation in hypospadias, followed by cryptorchidism and hydrocele of tunics vaginalis. More severe hypospadias is accompanied with a higher probability of the external genital system malformations, penoscrotal transposition and cryptorchidism.

Objective To investigate the genetic characteristic of whole-genome of influenza A/H3N2 viruses in severe acute respiratory infection cases in Beijing area.Methods From 2014 to 2016,the viral RNA was extracted from 32 strains isolated from SARI cases,then sequenced by Ion Torrent PGM Sequencer.The phylogeny and molecular features of whole-genome were analyzed by Mega and Consurf software.Results The HA gene of tested strains isolated in 2014-2015 influenza season belonged to lineage 3C.3a and 3C.2a,while those isolated in 2015-2016 influenza season belonged to cluster 3C.2a.Moreover,compared with the vaccine strains,7 variant amino acids of protein of HA1 were identified,and two of them were located in antigenic sites.All isolates were sensitive to neuraminidase inhibitors while showed resistance to blockers for M2 ion channel.Conclusion The phylogenetic features of isolates studied in this study are similar with that of current circulating strains.However,the difference between isolates and vaccines should not be overlooked.

Objective: To study the synergistic and additive effects of commonly used antibiotics on multi-drug resistant Gram-negative bacilli and to establish a database of combined pharmacodynamics in vitro. Methods: Seven antibiotics including fosfomycin (PHOS), levofloxacin (LEV), ceftazidime (CAZ), compound sulfamethoxazole (SMZ), piperacillin/tazobactam (TZP), cefoperazone/sulbactam (SCF) and imipenem (IMP) were selected and grouped into 21 drug pairs. Based on the results of extended spectrum β-lactamases (ESBLs) test and modified carbapenem inactivation method (mCIM), a total of 172 strains of multidrug-resistant Gram-negative bacilli were divided into four groups: 20 strains of carbapenem-resistant Klebsiella pneumoniae (group A), 50 strains of pan-resistant Acinetobacter baumannii (group B), 62 strains of ESBLs-producing Enterobacter (group C) and 40 strains of carbapenem-resistant Pseudomonas aeruginosa (group D). Chessboard dilution method was used to detect the in vitro combined efficacy of 21 drug pairs on drug-resistant bacteria from the four groups. Whonet 5.6 was used for statistical analysis. Results: All 172 strains were single drug resistant to the seven antibiotics. Results of the combined drug efficacy test showed that no antagonism was found in the four groups. In group A, ten drug pairs, especially the combination of PHOS+ LEV (30%, 6/20), had synergistic effects and 14 showed partial synergistic effects, but no additive effect was detected. Synergistic effects, partial synergistic effects and additive effects were respectively achieved by 12, ten and three drug pairs in group B. The LEV+ SMZ combination had synergistic effects against 56% (28/50) of the strains, which was the highest among all combinations. There were 14, 17 and 16 drug pairs showing synergistic effects, partial synergistic effects and additive effects in group C, respectively, and the strongest synergistic effects were achieved by the IMP+ LEV combination (30.6%, 19/62). There were 12, 14 and 13 drug pairs having synergistic effects, partial synergistic effects and additive effects in group D, respectively, and the strongest synergistic effects were achieved by the IMP+ LEV combination (20%, 8/40). Conclusions The combined use of quinolones, carbapenems, sulfonamides and PHOS could have good synergistic effects against multi-drug-resistant gram-negative bacilli. Monitoring the in vitro combined efficacy before treatment would improve the accuracy of antibiotic use and is of great clinical value.