Serotypes and drug resistance of non-typhoidal Salmonella in Zhengzhou City / 预防医学

Objective@#To investigate the serotypes and drug resistance of non-typhoidal Salmonella in Zhengzhou City, so as to provide insights into prevention and control of non-typhoidal Salmonella infections. @*Methods@#Salmonella isolates were collected from diarrheal patients in Zhengzhou municipal sentinel hospitals from 2017 to 2021. Salmonella serotypes were identified using slide agglutination test and soft agar colony formation assay, and antimicrobial susceptibility test was performed using the broth micro-dilution method. @*Results@# Five serogroups and 37 serotypes were identified among 446 non-typhoidal Salmonella isolates, with S. enteritidis (210 isolates, 47.09%) and S. typhimurium (133 isolates, 29.82%) as dominant serotypes. Non-typhoidal Salmonella showed high resistance to ampicillin (79.60%), ampicillin/sulbactam (58.74%), naphthyric acid (56.05%), tetracycline (54.26%) and doxycycline (54.04%), respectively. There were 290 multidrug-resistant Salmonella isolates (65.02%), and the multidrug resistance rates were 70.48% for S. enteritidis and 67.67% for S. typhimurium, respectively. @*Conclusions @#Multiple serotypes of non-typhoidal Salmonella were identified in Zhengzhou City from 2017 to 2021, with S. enteritidis and S. typhimurium as dominant serotypes. Widespread drug resistance and multidrug resistance was seen in non-typhoidal Salmonella.

Comparison of the efficacy of two Conbercept regimens in the treatment of polypoid choroidal angiopathy / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To observe the efficacy of two conbercept regimens in the treatment of polypoid choroidal angiopathy.<p>METHODS: Twenty-one patients with polypoidal choroidal vasculopathy who met the inclusion criteria and were treated in our hospital were randomly divided into two groups. The group A(9 patients and 9 eyes)was treated with 3+Q12W scheme, namely, 0.5mg conbercept ophthalmic injection was intravitreally injected every 4wk for 3 consecutive times, and then 1 time every 12wk. In the group B(12 patients and 12 eyes), 3+TAE scheme was carried out, that is 0.5mg conbercept ophthalmic injection was intravitreally injected every 4wks for 3 consecutive times. The time of next injection was determined according to the evaluation results of each visit. The interval to the next visit/treatment was ≥ 4wk and ≤ 12wk. The best corrected visual acuity(BCVA), central retinal thickness(CRT)and the frequency of injection were compared between the two groups at 12 and 48wk after treatment, respectively.<p>RESULTS: BCVA of the group A was 74.78±11.23 letters and 74.67±13.94 letters at 12 and 48wk after treatment, which increased by 7.00±4.21 letters and 6.89±4.48 letters at the baseline before treatment, respectively. BCVA in the group B was 77.83±5.46 letters and 77.58±8.59 letters respectively at 12 and 48wk after treatment, which were 8.75±7.54 letters and 8.50±5.60 letters higher than the baseline before treatment. At the 12 and 48wk after injection, the average CRT in the group A was 276.33±44.34μm and 240.56±40.11μm, respectively, which were 43.22±42.21μm and 79.00±53.64μm lower than the baseline before treatment. At the 12 and 48wk after injection, the average CRT in the group B was 271.58±63.08μm and 241.00±43.91 μm, which were 57.42±45.33μm and 88.00±61.16μm lower than the baseline before treatment, respectively. The average times of intravitreal injection of conbercept were 6.00±0.00 and 7.75±1.14 times in the 3+Q12W group and the 3+TAE group, respectively.<p>CONCLUSION: Two different regimens of conbercept could reduce the CRT and improve the visual acuity of the patients with polypoidal choroidal vasculopathy. And the times of intravitreal injection in the 3+Q12W administration group were less than those in the3+TAE administration group.

The oral health status of senile dementia patients: a systematic review / 口腔疾病防治

Objective @# To systematically evaluate the oral health status of senile dementia patients. @*Methods@#The CNKI, Wanfang, CBM, PubMed, Embase and Web of Science databases were searched online. Literature on the oral health status of Alzheimer′s patients published at home and abroad was collected. The search period extended to December 2018. Revman 5.3 software was used to perform the meta-analysis of homogeneous research.@*Results @#Ten studies satisfied the eligibility criteria. The meta-analysis revealed that older people with dementia had fewer remaining natural teeth [MD=-3.22 (95% CI -5.59, -0.85)] and more decayed missing filled teeth [MD=3.36 (95% CI 0.80, 5.92)] than the healthy control group (P < 0.05). The plaque index [MD=0.86 (95% CI 0.45, 1.28)], percentage bleeding on probing [MD=16.60 (95% CI 9.81, 23.39)], probing depth [MD=0.68 (95% CI 0.03, 1.34)], and clinical attachment loss [MD=1.13 (95% CI 0.38, 1.88)] were significantly higher in older people with dementia than in the healthy control group (P < 0.05).@*Conclusion @#The dental and periodontal health status of Alzheimer′s patients is worse than that of healthy controls. Thus, the former group needs special oral care and treatment.

Risk Factors for Preoperative Anxiety and Depression in Patients Scheduled for Abdominal Aortic Aneurysm Repair / 中华医学杂志(英文版)

Background@#Perioperative emotional disorders of patients underwent abdominal aortic aneurysm (AAA) repair is an emerging area of study, and preoperative mental distress of those patients remains poorly understood. The aim of this study was to investigate the prevalence and identify the risk factors of preoperative anxiety and depression in patients scheduled for AAA repair.@*Methods@#A total of 189 patients who underwent elective AAA repair between 2015 and 2016 were included in this study. These patients were preoperatively evaluated by Hospital Anxiety and Depression Scale (HADS). Demographics and anxiety and depression scores of the patients were documented. Logistic regression was used to identify the independent risk factors of preoperative anxiety and depression.@*Results@#A total of 150 AAA patients were included in final analysis. Of these 150 patients, 44 patients (29.3%) had borderline anxiety or clinical anxiety, and 42 patients (28.0%) were found to have borderline or clinical depression. Female (odds ratio [OR]: 2.81, 95% confidence interval [CI]: 1.08-7.26), the American Society of Anesthesiologists (ASA) Grade 3/4 (OR: 4.34, 95% CI: 1.13-16.68), higher education (OR: 1.44, 95% CI: 1.02-2.04), and abdominal or back pain (OR: 3.08, 95% CI: 1.20-7.87) were identified as significant independent risk factors of abnormal HADS-anxiety in overall patients; and higher level of education (OR: 1.87, 95% CI: 1.16-3.01) was predictive of anxiety in patients planned for endovascular aortic repair. Besides, higher body mass index (BMI) (OR: 1.18, 95% CI: 1.04-1.33) and abdominal or back pain (OR: 3.93, 95% CI: 1.70-9.11) were predictive of abnormal preoperative HADS-depression in overall patients.@*Conclusion@#As for patients scheduled for AAA repair, female, higher ASA, higher level of education, and symptom may be independent risk factors for preoperative anxiety, and symptom and higher BMI may predict preoperative depression.

Pars plana vitrectomy and Baerveldt glaucoma implant in the treatment of refractory glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the clinical efficacy of pars plana vitrectomy and Baerveldt glaucoma implant(PPV-BGI) in the treatment of refractory glaucoma.METHODS:One hundred twenty-nine refractory glaucoma patient's clinical data from March 2013 to December 2015 that underwent PPV-BGI were retrospectively reviewed.Among them,63 eyes were neovascular glaucoma (NVG) and 69 eyes were other types of glaucoma (non-NVG).The changes of intraocular pressure(lOP),surgical results,visual acuity (VA),the number of glaucoma medications,complications,and the success rate of surgery were analyzed.RESULTS:Cumulative success rates for the NVG group and non-NVG group were 46.0％ and 81.2％,respectively,within 1a after surgeries,the difference was significantly (P＜ 0.05).Preoperative lOP was 30.4 ± 10.2mmHg in the non-NVG group and 40.1±10.4mmHg in the NVG group,and lOP was reduced to 14.9±4.1mmHg in the non-NVG group and 17.8±4.9mmHg in the NVG,and the difference was significantly (P＜0.05).Number of glaucoma medications decreased from 2.7 ± 1.2 in the non-NVG group and 2.9 ± 1.4 in the NVG group preoperatively to 0.51 ±0.96 in the non-NVG group and 0.96±1.18 in the NVG group,and the difference was significantly (P＜0.05).Improvement in VA of in the NVG group and non-NVG group were observed in 14 eyes of 13 patients and 38 eyes and 37 patients respectively,and the difference was significantly (P＜0.05).The postoperative complications of 1d and 1a follow-up in NVG group was significantly higher than non-NVG group (P＜0.05).CONCLUSION:PPV-BGI is a viable surgical option for eyes with refractory glaucoma,but visual outcomes are frequently poor because of ocular comorbidities,especially in eyes with NVG.

CT manifestation for excavated-type of rhomboid fossa of the clavicle / 中国骨伤

<p><b>OBJECTIVE</b>To explore the manifestation of CT for excavated-type of rhomboid fossa of the clavicle.</p><p><b>METHODS</b>Nine cases with rhomboid fossaes of the clavicle of 8 patients accepted CT and 1 case added MRI together;all 8 patients were male who aged from 17 to 70 years old with mean age of 42.5 years old;three dimensional reconstruction of all CTs were made, the distance between focus and inside end of clavicle and the size of all focus were measured respectively, then the position, shape, margin of focus were analyzed.</p><p><b>RESULTS</b>All focuses located near the inside end of clavicle and the distances between focus and inside end of clavicle were lower than 2 cm and the mean value was 1.3 cm, the size of all focuses was from 1.05 to 3.45 cm and the mean value was 2.18 cm. All 9 focuses of 8 patients located in the posterior and nether edge of inside end of clavicle, 5 cases located in right and 4 cases located in left side(both right and left side occurred in 1 patient. Seven focuses showed "fishhook sign" and the rest 2 focuses were small and without fishhook shape;the cortex of clavicle of all 9 cases showed local minus and nearly marrow showed integrated sclerotic margin. Regular soft tissue as strip can be seen in 7 focuses and the rest small focuses without the symptom.</p><p><b>CONCLUSIONS</b>CT could show certain characteristics for excavated-type of rhomboid fossa of the clavicle and certain value for its diagnosis and identification.</p>

Tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography: association with N categories

OBJECTIVE: To determine whether the gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict the presence of regional lymph node metastasis and could determine N categories. MATERIALS AND METHODS: A total of 202 consecutive patients with gastric adenocarcinoma who had undergone gastrectomy 1 week after contrast-enhanced multidetector computed tomography were retrospectively identified. The gross tumor volume was evaluated on multidetector computed tomography images. Univariate and multivariate analyses were performed to determine whether the gross tumor volume could predict regional lymph node metastasis, and the Mann-Whitney U test was performed to compare the gross tumor volume among N categories. Additionally, a receiver operating characteristic analysis was performed to identify the accuracy of the gross tumor volume in differentiating N categories. RESULTS: The gross tumor volume could predict regional lymph node metastasis (p<0.0001) in the univariate analysis, and the multivariate analyses indicated that the gross tumor volume was an independent risk factor for regional lymph node metastasis (p=0.005, odds ratio=1.364). The Mann-Whitney U test showed that the gross tumor volume could distinguish N0 from the N1-N3 categories, N0-N1 from N2-N3, and N0-N2 from N3 (all p<0.0001). In the T1-T4a categories, the gross tumor volume could differentiate N0 from the N1-N3 categories (cutoff, 12.3 cm3), N0-N1 from N2-N3 (cutoff, 16.6 cm3), and N0-N2 from N3 (cutoff, 24.6 cm3). In the T4a category, the gross tumor volume could differentiate N0 from the N1-N3 categories (cutoff, 15.8 cm3), N0-N1 from N2-N3 (cutoff, 17.8 cm3), and N0-N2 from N3 (cutoff, 24 cm3). CONCLUSION: The gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict regional lymph node metastasis and N categories.

Inlaid labial versus bladder mucosal graft repair for complex urethral skin fistula / 中华男科学杂志

<p><b>Objective</b>To compare the effect of inlaid labial mucosal graft repair (LMGR) with that of bladder mucosal graft repair (BMGR) in the treatment of complex urethral skin fistula after hypospadias repair.</p><p><b>METHODS</b>This study included 55 cases of complex urethral skin fistula following hypospadias repair. We randomly assigned them to receive inlaid LMGR (n=36) or BMGR (n=19). After surgery, we compared the incidence of complications and recurrence rate of urinary fistula between the two groups of patients.</p><p><b>RESULTS</b>The success rates of operation were 91.7% and 84.2% in the LMGR and BMGR groups, respectively, and the penile appearance was desirable in both groups. Postoperative complications included 2 cases of urinary fistula and 1 case of urethral stricture in each group. There were no statistically significant differences between the two groups in the success rate of operation (P>0.05) or the incidence rate of postoperative complications (P>0.05).</p><p><b>CONCLUSIONS</b>Both inlaid LMGR and BMGR yield satisfactory results in the treatment of complex urethral skin fistula. However, LMGR involves less injury in mucosa collection and is easier to perform and therefore deserves more clinical attention.</p>

Synthesis, potential anticonvulsant and antidepressant effects of 2-(5-methyl-2,3-dioxoindolin-1-yl)acetamide derivatives

A new series of 2-(5-methyl-2,3-dioxoindolin-1-yl)acetamide derivatives were synthesized and evaluated for their anticonvulsive activity in a pentylenetetrazole (PTZ)-evoked convulsion model and antidepressant activity in the forced swimming test (FST) model. Eleven synthesized compounds were found to be protective against PTZ-induced seizure and showed the anticonvulsant activity. In addition, four of the synthesized compounds (4l, 4m, 4p and 4q) showed potent antidepressant-like activity. Among these compounds, compound 4l was found to have the most potent antidepressant-like activity, and significantly reduced the duration of immobility time at 100 mg/kg dose level when compared to the vehicle control, which is similar to the reference drug fluoxetine.

Electroacupuncture for the prevention of postoperative gastrointestinal dysfunction in patients undergoing vascular surgery under general anesthesia: study protocol for a prospective practical randomized controlled trial / 中西医结合学报

<p><b>BACKGROUND</b>Postoperative gastrointestinal dysfunction (PGD) is one of the most common complications following major surgeries under general anesthesia (GA). Despite ongoing research and new drug treatments, abdominal distension within 24 h postoperatively occurs in 8%-28% of all surgeries. We aim to analyze the effectiveness of preventing PGD by preoperatively stimulating Neiguan (PC6), Zusanli (ST36) and Shangjuxu (ST37) bilaterally twice a day compared with sham-acupuncture treatment and standard treatment.</p><p><b>METHODS AND DESIGN</b>This is a single-center, prospective practical randomized controlled trial. All groups will be given standard treatments. Patients undergoing vascular surgery under GA will be included from the Vascular Surgery Unit in West China Hospital of Sichuan University, China, and divided into three groups. The experimental group will receive routine treatments and acupuncture at PC6, ST36 and ST37 bilaterally with electrical stimulation twice a day for 20 min preoperatively. The sham-acupuncture group will receive pseudo-electroacupuncture at sham acupoints of PC6, ST36 and ST37, which are 1 cun away from the real acupoints. The routine-treatment group will not receive electroacupuncture. The outcomes include the incidence of abdominal distention, abdominal circumference, the degree of abdominal distension, the first time of flatus and defecation, and hospitalization duration.</p><p><b>DISCUSSION</b>The results from this study will demonstrate whether preoperative electroacupuncture is an effective method for the prevention of PGD in patients undergoing vascular surgery under GA. This study may also provide a standardized acupuncture treatment for reduction of PGD.</p>

Study on in vitro biomineralization of enamel-binding peptide / 生物医学工程学杂志

We present the binding ability of a new peptide (CMPQVMPMC-) with dental enamel after being evaluated in the present study. Under a standard procedure, the recovery of M13 filamentous phage was greatly enhanced by displaying the peptide in phage coat protein p III. Then the cyclic peptide was synthesized using a solid method. The effect of the cyclic peptide in vitro biomineralization was tested in a single-diffusion microtiter plate gel system. Absorbance at 405 nm of each sample was recorded for 24 h at every 6 h intervals. The relatively increased values of each sample were expressed as percentages relative to the blank group (100%). The cyclic peptide resulted in a concentration-dependent delayed nucleation. In addition, the overall values of peptide groups at the end of 24 h were lower than those in the control group but much higher than those in the BSA control group.

MicroRNA383 regulates expression of PRDX3 in human medulloblastomas / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of microRNA-383 (miR-383) on PRDX3 gene expression, cell proliferation and apoptosis of human medulloblastma.</p><p><b>METHODS</b>PRDX3 and miR-383 RNA expression was detected by real-time quantitative RT-PCR in human medulloblastoma tumor tissue samples, Daoy cell line and normal brain tissue samples. Western blot was used to detect protein expression of PRDX3. Synthetic miR-383 mimics were transfected into Daoy cells by lipofectamine. Using Cell Counting Kit-8 (CCK-8) method, flow cytometry was used to investigate the cell proliferation and apoptosis, cells reactive oxgen species(ROS), mitochondrial membrane potential changes in each experimental groups.</p><p><b>RESULTS</b>Of 15 cases of human medulloblastoma tumor, 13 cases had miR-383 expression levels significantly lower than that of normal brain tissue, and 14 had PRDX3 mRNA expression levels significantly higher than that of normal brain tissue. The expression levels of miR-383 and PRDX3 in Daoy cells were 0.353 and 1.315 times than those of normal brain tissue, respectively. The protein expression levels of PRDX3 were higher in human medulloblatoma tumors and Daoy cells than that of normal brain tissue. Transfected miR-383 mimics increased the expression level of miR-383 after 24 h and 48 h was significantly higher than that of the control. In contrast, PRDX3 gene mRNA and protein expression levels were significantly decreased at 48 h compared with the control group. Using CCK-8 assay, the cell proliferation rate in the experimental group was significantly lower than that of the control group (P < 0.05). Annexin V-FITC assay demonstrated that early apoptosis rate of the experimental group (11.60 ± 0.30)% was significantly higher than those of the control group (2.3 ± 0.20)% and negative control group (10.37 ± 0.25)% (P = 0.000) after 48 h of transfection. The intracellular ROS levels after transfection at 24 and 48 h significantly increased than those of the control group. Mitochondrial membrane potential level at 24 h after transfection significantly decreased, comparing with the blank control group and the negative control group.</p><p><b>CONCLUSIONS</b>Compared with normal brain tissue, decreased expression of miR-383 but elevated expression of PRDX3 are medulloblastoma tumour and Daoy cell lines. Up-regulation of miR-383 knockdowns the expression of PRDX3, inhibits proliferation and promotes apoptosis of Daoy cells, leading to increased intracellular ROS and decreased levels of mitochondrial membrane potential.</p>

Dynamic contrast-enhanced MSCT findings of intraductal papillary neoplasm of the bile ducts / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the findings of contrast-enhanced multislice computed tomography (MSCT) that characterize intraductal papillary neoplasms of bile ducts (IPNB).</p><p><b>METHODS</b>The MSCT findings and clinical data of 16 cases of IPNB proven by surgical pathology were reviewed retrospectively.</p><p><b>RESULTS</b>Among the 16 cases, nine were adenoma (multi-lesions, n = 5; single lesions, n = 4) and seven were adenocarcinoma (multi-lesions, n = 4; single lesions, n = 3). Among the nine adenoma cases, seven showed nodules or masses in the expanding intrahepatic bile ducts with asymmetrical low density on plain scan, and two showed obvious expansion of biliary ducts and the inner wall of bile ducts was rough. All seven of the adenocarcinoma cases showed nodules or masses in the expanding intrahepatic bile ducts with asymmetrical low density-like adenoma. When contrast enhancement was applied, the nine adenoma cases manifested slight-to-moderate degrees of asymmetrical enhancement. For the seven adenocarcinoma cases, two showed asymmetrical enhancement similar to that of the adenoma cases and five showed continued enhancement; one case showed malignant infiltration of the bile duct and evident damage in the adjacent hepatic tissue. The CT plain scan findings for the two groups (adenoma and adenocarcinoma) were not significantly different (t = -1.17, P = 0.2632). Significantly different findings were obtained with the MSCT imaging analysis for the arterial phase (t = 6.53, P less than 0.01) and the portal vein phase (t = 5.63, P less than 0.01). All cases showed asymmetrical expansion of intrahepatic biliary ducts, diffuse or local, and four cases showed moderate expansion of the common bile duct. One adenocarcinoma case showed intumescence in the celiac lymph node by moderate asymmetrical enhancement.</p><p><b>CONCLUSION</b>MSCT is helpful for the differential diagnosis of IPNB from other hepatic lesions.</p>

Study on effects of microRNA-21 antisense oligonucleotide in vivo and in vitro on bionomics of human cervical squamous carcinoma cell lines SiHa / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore the effect of microRNA-21 (miR-21) antisense oligonucleotide on the biological characteristics of human cervical squamous carcinoma cell lines SiHa in vivo and in vitro.</p><p><b>METHODS</b>Specific phosphorothioate antisense oligodeoxynucleotides targeting miR-21 were synthesized and transfected into cervical cancer cells in vitro. Expression of miR-21 in SiHa after transfection was detected by real-time RT-PCR. The cell proliferation was evaluated by MTT assay and colony formation experiment. The cell apoptosis was analyzed by annexin V-FITC/PI analysis. The inhibitory effect of miR-21 antisense oligonucleotide on tumor growth was evaluated by tumor growth curves and immunohistochemistry (MaxVision method). H-E staining was used to document morphological changes and fluorometric TUNEL assay was to detect the apoptotic activity.</p><p><b>RESULTS</b>After the transfection of antisense miR-21, the expression of miR-21 decreased along with an obvious growth inhibition, compared with that of the control groups (P < 0.05). Colony formation of both cell lines was markedly inhibited with antisense miR-21 (55.6% ± 1.4%), as compared with that in the negative group (98.3% ± 2.0%, P < 0.05). Flow cytometry assay showed that antisense miR-21 expression significantly enhanced the cell apoptosis (6.7% ± 1.3% and 29.4% ± 1.7%, P < 0.05). The tumor-forming rates of miR-21 transfected group, and negative control groups were 3/8 and 6/8, respectively (P < 0.05). Ki-67 proliferative marker staining decreased significantly (42% vs 90%) in the transfected group compared with negative control groups. Extensive dead tumor cells were seen in the miR-21 transfected cells along with a marked increase of apoptosis (P < 0.05).</p><p><b>CONCLUSION</b>Targeted antisense oligonucleotide miR-21 effectively suppresses the growth of cervical carcinoma SiHa cells both in vitro and in vivo through an induction of apoptosis.</p>

Clinical significance of tumor interstitial T lymphocyte subset activity in non-small-cell lung cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relation of tumor interstitial T lymphocyte subset activity to the clinical staging of non-small-cell lung cancer (NSCLC) and the immune response.</p><p><b>METHODS</b>Immunohistochemical staining for CD4(+), CD8(+) and CD4(+)CD25(+) Foxp3(+) (regulatory T cells, Treg) T cells was performed on paraffin-embedded tissues from 60 NSCLC cases.</p><p><b>RESULTS</b>Compared to stage I/II NSCLC patients, patients in stage III/IV showed a significant decrease in the percentage of CD4(+) and CD4(+)/CD8(+) T cells (P<0.05) and an increase in CD8(+) and CD4(+)CD25(+) Foxp3(+) T cells (P<0.05). Treg cells were enriched in the tumor tissue as compared with those in the adjacent tissues.</p><p><b>CONCLUSIONS</b>The proportion of CD4(+)CD25(+) Foxp3(+) Treg cells is positively correlated to the clinical staging of NSCLC, in which T cell-mediated immune response is suppressed.</p>

Design and development of the DSA digital subtraction workstation / 中国医疗器械杂志

According to the patient examination criterion and the demands of all related departments, the DSA digital subtraction workstation has been successfully designed and is introduced in this paper by analyzing the characteristic of video source of DSA which was manufactured by GE Company and has no DICOM standard interface. The workstation includes images-capturing gateway and post-processing software. With the developed workstation, all images from this early DSA equipment are transformed into DICOM format and then are shared in different machines.

Bioinformatic studies on the group 2 allergens of Dermatophagoides farinae from China.

The present study aimed to characterize the group 2 allergens of the house dust mite Dermatophagoides farinae (Der f 2) from Hainan Island, a tropical region in Southeastern China. We cloned and sequenced cDNA coding for Der f 2 and found an additional region of 87 base pairs (bp) (from +77 to +163 bp) in our strain that was absent in the reference sequence (GenBank AB195580) used for primer design. However, the BLAST analysis identified the same sequence in strains reported from Reinbek, Germany, and Guangzhou, China. A phylogenetic tree was constructed using the Der f 2 nucleotide sequences from different regions or countries and showed that the Hainan sequence clustered with the strains from Reinbek and Guangzhou. Analysis of the translated amino acid sequence suggests that the encoded peptide is hydrophobic and extracellular with a cleavage site between the 17th and 18th amino acid residues and contains a strong trans-membrane helix from the 6th amino acid to the 24th amino acid, indicating a MD-2-related lipid recognition domain in this protein. Furthermore, the secondary structure of the pro-protein consists of 16.57% alpha helix, 32.57% extended strand and 50.86% random coil. In brief, we obtained a gene coding for Der f 2 and predicted the molecular characteristics of this protein using bioinformatics tools. Our analysis identified that this gene showed several significant differences to those reported previously.

Three-dimensional finite element analysis of the mechanical stress on root from orthodontic tooth movement by sliding mechanics / 华中科技大学学报（医学）（英德文版）

In order to study mechanical stress on root from orthodontic tooth movement by sliding mechanics, a 3-dimensional finite element model incorporating all layers of a human mandibular dental arch with orthodontic appliance has been developed to simulate mechanical stress on root from the orthodontic tooth movement. Simulated orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis was applied to the crown of the teeth. The finite element analysis showed when orthodontic forces were applied to the tooth, the stress was mainly concentrated at the neck of the tooth decreasing uniformly to the apex and crown. The highest stress on the root was 0.621 N/mm(2) for cervical margin of the canine, and 0.114 N/mm(2) for apical region of the canine. The top of canine crown showed the largest amount of displacement (2.417 microm), while the lowest amount of displacement was located at the apical region of canine (0.043 microm). In conclusion, this model might enable one to simulate orthodontic tooth movements clinically. Sliding force at 2 N is ideal to ensure the bodily orthodontic tooth movement. The highest stress concentration in the roots was always localized at the cervical margin when orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis, so there may be the same risk of root resorption when orthodontic force of 2 N at 0, 30 and 45 degree was used in clinic cases.

Three-dimensional Finite Element Analysis of the Mechanical Stress on Root from Orthodontic Tooth Movement by Sliding Mechanics / 华中科技大学学报（医学）（英德文版）

In order to study mechanical stress on root from orthodontic tooth movement by sliding mechanics, a 3-dimensional finite element model incorporating all layers of a human mandibular dental arch with orthodontic appliance has been developed to simulate mechanical stress on root from the orthodontic tooth movement. Simulated orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis was applied to the crown of the teeth. The finite element analysis showed when or- thodontic forces were applied to the tooth, the stress was mainly concentrated at the neck of the tooth decreasing uniformly to the apex and crown. The highest stress on the root was 0.621 N/ram2 for cer- vical margin of the canine, and 0.114 N/mm2 for apical region of the canine. The top of canine crown showed the largest amount of displacement (2.417 μm), while the lowest amount of displacement was located at the apical region of canine (0.043 μm). In conclusion, this model might enable one to simulate orthodontic tooth movements clinically. Sliding force at 2 N is ideal to ensure the bodily or- thodontic tooth movement. The highest stress concentration in the roots was always localized at the cervical margin when orthodontic force of 2 N at 0, 30 and 45 degree from the horizontal axis, so there may be the same risk of root resorption when orthodontic force of 2 N at 0, 30 and 45 degree was used in clinic cases.