Objective To develop and evaluate an aptamer based biosensor (aptasensor) for rapid colorimetric detection of enteropathogenic Escherichia coli (EPEC). Method The aptasensor was fabricated by modifying the truncated LPS-binding aptamer on the surface of nanoscale polydiacetylene vesicles using peptide bonding between the carboxyl group of the vesicle and the amine group of the aptamer. Molecular recognition between EPEC and aptamer at the interface of the vesicle led to blue-red transition of polydiacetylene which was readily visible to the naked eyes and could be quantified by colorimetric responses (CR). Transmission electron microscopy (TEM) was used to confirm the specific interactions between EPEC and polydiacetylene vesicles. Result Truncated aptamer showed the similar LPS-binding activity. The aptasensor could detect the target bacteria in a range of 105-108 colony-forming units (CFU)/ml within less than 30 minutes and its specificity was 100% for detection of EPEC O111. The sensor reproducibiliry obtained at 106 CFU/ml was 6. 08% R. S. D. The results of TEM confirmed that the specific interactions between EPEC and polydiacetylene vesicles. Conclusion A new aptasensor was developed successfully for rapid colorimetric detection of EPEC.

Objective To investigate the differences of clinicopathologic characteristics and prognosis between young and old age patients with rectal cancer. Methods From January 1996 to January 2006, 85 young patients(age≤40 years) and 155 older patients(age≥65 years)with rectal cancer were surgically treated. The clinicopathological and follow-up data of them were retrospectively analyzed and compared by survival analysis and COX regression multivariate analysis. Results Rectal cancer under peritoneal in young group were higher than that in older group (69.41 % vs 52.90 %, P =0.013). The young group had significantly higher frequencies of pooly differentiated carcinoma (31.76 % vs 18.71 %, P =0.023) and more mucinous adenocarcinoma as well as signet-ring cell carcinoma (22.35 % vs 8.39 %, P =0.007), There were more lymphatic metastasis in young group than that in old group (N_1+N_2: 63.53 % vs 47.10 %, P =0.015). The overall 5-year survival rates were 48.2 % and 55.7 % in young and old patients respectively, which was not significantly different (P =0.176). COX regression showed that radical operation, tumor infiltration depth,lymph node metastasis and TNM stage were independent prognostic factors. Conclusion As compared to the old age patients, more malignancy and more advanced stage are common in young patients with rectal cancer.However the efficacy of young patients is similar to the older counters by early detection and radical operation combined radiotherapy as well as chemotherapy.

Objective To compare clinicopathological characteristics and prognosis between triple-negative and HER-2-overexpressed breast cancer patients.Methods From Jan.1997 to Jan.2007,data of 725 cases of primary breast cancer patients undergoing surgical treatment were analyzed.The patients were classified into triple-negative and HER-2-overexpressed phenotypes based on immunohistochemistry results.The clinicopathological characteristics and survival of the 2 groups were compared.Results Of the 725 cases,triple-negative and HER-2-overexpressed phenotypes accounted for 12.29%and 24.96%respectively.Compared with HER-2-overexpressed group,the triple-negative group had significantly higher proportion of familial history of malignancy (18.4% vs 5.5%,P=0.001)and higher proportion of patients'histological grade reaching grade 3(54.0% vs 42.0%,P=0.01).There were more lymph node metastasis in triple-negative group than that in HER-2-overexpression group(N1+N2+N3:74.7%vs 64.6%,P=0.045).The recurrence and metastasis rate within 2 years and brain metastasis rate in triple-negative group were higher than those in HER-2-overexpressed group (25.3%,8.0%vs 8.8%,2.2%,respectively,P<0.05).The 5-year disease-free survival rate in triple-negative group was significantly lower than that in HER-2-overexpressed group(55.6%vs 69.8%,P=0.041).There was no statistical difference between the 2 groups in terms of age,menopausal status,tumor size,pathological stage,surgcal procedure,pathological type,adjuvant radio-chemotherapy,the proportion of metastasis to liver,lung and bone as well as overall survival rate(P>0.05).Conclusion Compared to HER-2-overexpressed group,patients with triple-negative breast cancer show higher rate of familial history of malignancy,and they are associated with higher histological grade and poor prognosis.

Objective To investigate the clinicopathologic features and treatment of thyroid microcarcinoma (TMC). Methods From January 1997 to December 2006,311 patients who underwent surgery and defined as TMC(tumor size≤1 cm)were enrolled. Results TMC was identified incidentally by frozen pathologic examination on thyroidectomy specimens in tentative benign goiters in 181 patients; another 130 patients with clinically detectable primary tumors or suspected nodal metastases were grouped to as clinically overt TMC. The clinically overt TMC had a higher incidence of bilateral multifocal tumors (18.5%vs.9.4%,P=0.03),and cervical lymph node metastases(27.7%vs.10.5%,P=0.000)than that in clinically occult TMC group. Conclusion TMC may vary considerably in clinical and biologic behaviors between these two subtypes: clinically overt and occult. Lobectomy for single lesion, total or near total thyroidectomy for multifocal with central compartment nodal dissection should be performed, lateral nodal dissection was not carried out unless US or physical examination detected nodal metastases. Lobetomy, subtotal or more limited thyroidectomy for occult TMC, diagnosed incidentally following thyroid surgery for initially tentative benign thyroid disease, could all be treatment of choice depending on the preference of surgeons.

The present paper was conducted to a systematic method of surgical guide for dental implant based on computer-aided technology through CT data and dental-cast data. By analyzing the patient's CT data, the implant region was planned using image processing techniques. For the specified implant region, the computer-aided method for the rational allocation of dental implant was addressed in a sense of anatomy. With biomechanical principles as well as aesthetical and functional requirements as preconditions, this method can make full use of bone quantity and quality to produce the optimum implantation axis. The transferring of implant planning to the patient was then realized by registration between CT models and dental-cast models. A case research explained the whole process of the surgical guide. The results validated the correctness and feasibility of this method, which has a great significance to enhance the quality and accuracy of implant surgery.
Computer-Aided Design ; Dental Implantation, Endosseous ; instrumentation ; methods ; Dental Models ; Dental Prosthesis Design ; instrumentation ; methods ; Humans ; Oral Surgical Procedures, Preprosthetic ; methods ; Patient Care Planning ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed

Objective To evaluate the change of clinicopathological features and prognosis of papillary thyroid cancer over a 15-year period.Methods The clinicopathological features and outcomes of papillary thyroid cancer patients were analyzed in three groups according to the time of diagnosis:group Ⅰ (1997-2001),group Ⅱ (2002-2006),and group Ⅲ (2007-2011).Results As time advanced,the average age of papillary thyroid cancer patients increased,tumor stage,like size,extrathyroid invasion and lymph node metastasis decreased dramatically (P ＜ 0.01).The percentage of multifocality and bilaterality increased.The long-term follow up data (median follow up time was 6.6 years),indicated that the 15-year over all survival was 97.8％ and the 15-year disease-free survival was 90.2％.Tumor ≥3 cm,bilaterality,extrathyroid invasion,lymph node metastasis and AJCC stage were correlated with tumor recurrence.By multivariate COX-regression analysis only lymph node metastasis and bilaterality were independent risk factors.Conclusion The clinicopathological features of papillary thyroid cancer changed over 15 years,with the percentage of early-staged patients increased.Lymph node metastasis and bilaterality are two risk factors for tumor recurrence.

Objective:To explore the molecular mechanisms of a Chinese pedigree with hereditary factor Ⅺ (FⅪ) deficiency.Methods:All of the 15 exons, flanking sequences of the FⅪ gene and the corresponding mutation sites of family members were analyzed by the Sanger sequencing, followed by the extraction of the peripheral blood genomic DNA. And all the results were verified by the reverse sequencing. The conservation of the mutated sites was analyzed by the ClustalX-2.1-win. Three online bioinformatics software tools, including Mutation Taster, PolyPhen2 and the PROVEAN, were used to assess the possible impact of the mutations. Swiss-pdbviewer software was used to analyze the effects of mutant amino acids on protein structure.Results:Genetic analysis revealed that the proband had compound heterozygous mutations including a nonsense mutation of c. 1107C>A (Tyr369stop) in exon 10 and missense mutation of c. 1562A>G (Tyr521Cys) in exon 13. The same c. 1107C>A (Tyr369stop) was present in her father, the same c. 1562A>G (Tyr521Cys) was present in both her mother and daughter. Conservation analysis indicated that Tyr521 was a highly conserved site during evolution. The prediction of pathogenicity showed that both c. 1107C>A and c. 1562A>G were pathogenic mutations. Protein structure prediction showed that in the wild type FⅪ protein structure, Tyr521 formed a hydrogen bond with the Lys572 and Ile388, respectively. When Tyr521 was replaced by Cys521, the original benzene ring structure disappeared, and side chains of Lys572 added a hydrogen bond with the Cys521, which may chang protein catalytic domain structure. When Tyr369 was mutated to a stop codon, resulting in the truncated protein.Conclusion:The compound heterozygous mutations including the c. 1107C>A heterozygous missense variant in exon 10 and the c. 1562A>G heterozygous nonsense mutation in exon 13 may be responsible for the hereditary factor Ⅺ deficiency in this Chinese pedigree.