Objective:To evaluate the ability of calcium hydroxide removal using different irrigation methods and the effect on canal sealing.Methods:200 human single root canal premolar teeth were prepared.Divided the teeth randomly into 2 groups(each group 96 teeth,8 as control),one group filled with chemical calcium hydroxide and another filled with finished product calcium hydroxide.7 days after,divided each groups randomly into 6 subsets and remove the calcium hydroxide in the root canal(table1).Then each subset group choose 8 teeth randomly,observed by scanning electron microscope.Other specimens were obturated by lateral condensation of cold gutta-percha with a AH-Plus sealer,stained by Indian ink and then made into transparent teeth model.Results:At the same condition,there was no significant difference between group A and group B;the results of groups associated with ultrasonic were better than groups with injection syringe.The rinse solution EDTA was the best,distilled water was the worse.Dye penetration showed that the length of dye staining was no significant difference among all groups.Conclusion:Ultrasonic and sodium hypochlorite associate EDTA is the best method to remove the calcium hydroxide.But none of the methods and rinse solution used in this experiment can remove all of the calcium hydroxide.The calcium hydroxide remained influence on the root canal sealer is not predominance.

Objective To investigate the clinical efficacy of open radical mastoidectomy (ORM) combined with ear cavity angioplasty and mastoid cavity obliteration in treatment of cholesteatoma otitis media (COM). Methods Eighty-two patients with COM were divided into 2 groups according to surgical approach: control group (41 patients undergoing simple ORM) and observation group (41 patients undergoing ORM combined with ear cavity angioplasty and mastoid cavity obliteration). The clinical efficacy and recurrence rate between the 2 groups were compared. Results The total effective rate, dry ear rate and eardrum healing survival rate in observation group were significantly higher than those in control group: 95.12% (39/41) vs. 78.05% (32/41), 97.56% (40/41) vs. 75.61% (31/41) and 90.24%(37/41) vs. 73.17% (30/41), and there were statistical differences (P<0.01). The dry ear time and epithelialization time in observation group were significantly shorter than those in control group:(31.23 ±5.69) d vs. (48.12 ± 8.97) d and (24.41±3.23) d vs. (36.24 ± 5.69) d, the postoperative pure tone audiometry (PTA) and air bone gap (ABG) in observation group were significantly lower than those in control group:(25.61 ± 5.67) dB vs. (35.41 ± 8.23) dB and (13.24 ± 3.98) dB vs. (19.02 ± 5.52) dB, and there were statistical differences (P<0.01). There was no statistical difference in the incidence of complications between 2 groups (P>0.05). The recurrence rate in observation group was significantly lower than that in control group:2.44%(1/41) vs. 14.63%(6/41), and there was statistical difference (P<0.05). Conclusions The application of ORM combined with ear cavity angioplasty and mastoid cavity obliteration in the treatment of COM has significant effect, with rapid postoperative dry ear and epithelialization, fewer complications and lower recurrence rate. It should be widely applied.

Objective To investigate the relationship between inducible nitric oxide synthase(iNOS)mRNA expression of pancreatic tissues and intestinal permeability,and the effect of salviae miltiorrhizae on the change in gut permeability in rats with severe acute pancreatitis(SAP).Methods All rats were randomly divided into three groups:Sham operation(group C,n=15),SAP group(group SAP,n=15),and salviae miltiorrhizae therapeutic group(group T,n=15).At 24h After operation,the iNOSmRNA expressions of pancreas were determined by in situ hybridization(ISH),and blood amylase(AMY),nitric oxide(NO) and lipopolysaccharide(LPS) were examined.The histopathologic changes of pancreas and ileum were observed.Intestinal permeability was measured by means of albumin clearance(AC)of 125I-labeled rat serum albumin.Results The iNOSmRNA expressions of pancreas in group SAP were markedly increased in comparison with group T(P

Objective To investigate allele frequency distributions and haplotype polymorphism of ten Y-chromosome short tandem repeats (STR) loci of Han population in Zhuhai area and evaluate their applicability to forensic cases. Methods DYS393, DYS19, DYS389 Ⅱ, DYS390, DYS391, DYS389 Ⅰ, DYS439、DYS438、DYS392 and DYS385 loci were amplified with Y-plex~(TM) PCR amplification Kit and analyzed by ABI 310 genetic analyzer. 200 unrelated male individuals of Han nationality in Zhuhai were recruited for determination of allele frequencies and haplotype data. Results 5, 6, 6, 5, 4, 5, 5, 5, and 7 alleles were found in 9 of the 10 Y-STR loci, respectively and 44 haplotypes were detected at DYS385 locus. The range of gene diversity (GD) was determined between 0.3904 for DYS391 and 0.9497 for DYS385. Total 161 haplotypes were found at the 10 Y-STR loci, of which 134 occurred once, 20 occurred twice, 3 occurred three times, 3 occurred four times, and 1 occurred five times. The cumulative GD was 0.9948. Conclusion The 10 Y-STR loci are highly polymorphic and suitable for forensic individual identification and paternity testing in Zhuhai Han population.

Plasma D-dimer is one of the degradation products of the cross-linked fibrin hydrolyzed by fibrinolysin and is also a unique metabolite of secondary fibrolysis.The change of its content is a reliable indicator for the identification of the hypercoagulabale state in vivo and primary and secondary fibrinolysis,as well as for the observation of the effectiveness of thrombolytic therapy.In recent years,D-dimer determination has gained new clinical application.

ISO 15189 standard quality management system developed by the International Organi-zation for Standardization (ISO) embodies the international medical laboratory's latest quality management concept, and puts forward the quality improvement method of the standard. In this research, ISO 15189, as an important content in practice teaching for laboratory medicine, was designed according to the elements of this system. Students were requested to participate in every linkage of laboratory quality management by writing system document, taking part in quality activity, and practicing the key and difficult points of tech-nique in quality system in order not only to cultivate their basic idea of ISO 15189 standard, but also to make them familiar with the basic patterns of laboratory accreditation system and process, which could make them become the backbone of the laboratory quality management quickly in their vocational positions in the future.

Objective To study the correlation between chronic gastritis with benign mucosal nodular-change,Helicobacter pylori(H.pylori)infection and lymphoid follicles infiltration.Methods During July 1,2004 to June 30,2005 patients with chronic gastritis and benign mucosal nodular-change were identified by chromo-endoscopy with anabrosis indigo carmine staining at the antrum.Multiple biopsies were obtained for H.pylori detection with quick test and for pathology examination of mucosal lymphoid follicles formation and lymphocyte infiltration,as well as H.pylori infection.Results The patients were divided into nodular gastritis group,atrophy gastritis group and verrucous gastritis group with mean age of(31.00?11.62),(58.61?12.14)and(51.29?12.99)years old,respectively.The patients with nodular gastritis were the youngest(P

Cancer is still one of the major diseases threatening human life and health. At present, how to achieve precise diagnosis and treatment of tumors is the biggest challenge in cancer treatment. Prodrugs use the tumor specificity of targeting molecules to deliver anticancer drugs to tumor sites, which can effectively improve drug bioavailability, therapeutic efficacy and safety, and are currently a hot spot in the research and development of anticancer drugs. The targeting molecules of prodrugs mainly include nucleic acid aptamers, polymers, antibodies, polypeptides, etc. Among them, polypeptides have the advantages of good biocompatibility, controllable degradation performance, high in vivo responsiveness, and simple and easy preparation methods, and are widely used. It is used to construct peptide-drug conjugates (PDC) prodrugs to achieve targeted therapy of tumors. In recent years, with the development of phage peptide library technology and peptide standard solid-phase synthesis technology, more and more targeted peptides have been discovered and effectively synthesized and modified, providing strong support for the development of PDC. This review briefly introduces the types and functions of functional peptides and linkers in PDC, and discusses the application of PDC in chemotherapy, immunotherapy and photodynamic therapy in tumor targeted diagnosis and treatment, and finally summarizes the difficulties faced by PDC drug development.

Objective To investigate the expression and biological function of microRNA-34a (miR-34a) in bladder cancer.Methods Forty-two cases of bladder cancer specimen,including 17 noninvasive carcinoma and 25 muscle invasive carcinoma classified by UICC 2002 TNM,or 18 low-grade and 24 high-grade classified by WHO 1973.Meanwhile,mucosa adjacent to the carcinoma was selected as normal control.The gene expression of miR-34a was determined using real-time quantitative polymerase chain reaction in 42 cases of bladder carcinoma samples.Mature mimics of miR-34a were chemically synthesized and transiently transfected-intoT24 bladder cancer cells.The effects of miR-34a on apoptosis and proliferation in T24 cells were evaluatedby flow cytometry and MTS respectively.Results 61.9％ of carcinoma samples showed low expression of miR-34a,which was correlated with the malignancy and tumor size of bladder carcinoma.26.5％ (11 cases) was negative and 11.6％ (5 cases) showed high expression.Furthermore,upregulation of miR-34a in T24 cells contributed to cell growth and apoptosis.The apoptosis rate of T24 cells was (9.11 ± 0.41)％,which had significant difference compared with NC mimics and blank control group respectively (P ＜ 0.01).Conclusion The relative low expression of miRNA-34a may be involved in the tumorigenesis and development of bladder carcinoma.

Objective To evaluate the inter -list equivalency of the disyllabic materials for Mandarin speech perception test (MSP) by measuring the speech recognition score of patients with cochlear implant (CI) .Methods According to Latin -square design ,disyllabic recognition scores (quiet background) were measured for each of the 10 phonemically balanced lists in 50 Mandarin-speaking CI users(aged 30 .44 ± 12 .71 years)in sound field .RM -ANOVA was administered to confirm the list equivalency .Results The sentence recognition scores were 59 .26% ± 23 .49% ,64 .31% ± 23 .35% ,59 .97% ± 23 .07% ,62 .40% ± 25 .16% ,62 .75% ± 24 .47% ,62 .29% ± 23 .55% , 62 .85% ± 24 .60% ,61 .35% ± 23 .73% ,61 .82% ± 25 .28% ,58 .83% ± 25 .13% ,respectively for the 10 lists .There was no significance difference in sentence recognition scores across the 10 disyllabic lists [F(9 ,490)=0 .255 ,P=0 .986>0 .05] .Conclusion The good inter -list equivalency of the disyllabic materials for Mandarin speech perception test (MSP) has been proved to be useful for assessing speech recognition performance of Mandarin -speaking CI users .