Objective To explore pre C and YMDD motif mutant of hepatitis B virus during lamivudine therapy. Methods From five chronic hepatitis B patients with serum HBeAg seroconversion but HBV DNA positive by polymerase chain reaction(PCR) following lamivudine therapy, sequences of the pre C and P genes of hepatitis B virus were analyzed by direct PCR product sequencing methods. Results All the five patients were observed to have G to A variations at nucleotide 1896. However, such mutations were observed only in 2 of the 5 patients before HBeAg seroconversion emerged. Meanwhile YMDD mutations were found in all the five patients during lamivudine therapy three of which were M552I mutants, two were M552I associated with L528M. One of the five patients had no reaction to the therapy, four had HBV DNA breakthrough during therapy. Conclusions The mutants of pre C associated with YMDD mutations may arise in the patients with HBeAg seroconversion and positive HBV DNA during the treatment of lamivudine. HBV DNA should be detected in the patients with HBeAg seroconversion to exclude the pre C mutation.

Objective Setting up a method to detect YMDD mutation during lamivudine therapy. Methods Two specific fluorescent probes were designed, on the unpaired base can remarkably affect melting temperature when oligonucleotide probe binding to DNA template. 297 patients (354 sera samples) were detected YMDD mutation by real time fluorimetry PCR. Results 156 YMDD mutation were found in 354 sera samples (44.1%), in which the mixed variant species were 34%(53/156). In the same time, nine sera samples wre sequenced. The results of sequencing were fully corresponded to those of fluorimetry PCR. The statistical analysis showed that YMDD variants were obviously correlated with ALT level(P

Objective To discuss the application value of DWI and ADC on predicting therapeutic effect of radiotherapy treatment in NPC. Methods Twenty four local recurrent cases and 38 non-recurrent cases after radiotherapy treatment in NPC were reviewed. MRI and DWI-MRI were performed at pre-radiotherapy and 3, 6, 12 months after treatment, the ADC values of the lesions were analyzed by SPSS 18.0 statistical software. ROC curves based on the ADC values were measured in 3, 6, 12 months after treatment plotted to analyze the threshold ADC value for confirming recurrence. Results The recurrent group and newly diagnosed group showed significantly high signal on DWI, while the non-recurrent group acquired low or mixed signal. The ADC values of the primary tumor in the recurrent group and the non-recurrent group were (0.709 ± 0.078) × 10-3 and (0.693 ± 0.089) × 10-3mm2/s, respectively, t=-0.717,P>0.05, respectively.The ADC values of the primary and recurrent tumor in the recurrent group were (0.730± 0.068) × 10-3mm2/s and (0.709 ± 0.078) × 10-3mm2/s, t=-1.000,P>0.05 , respectively.There were statistical differences between the recurrent group and the non-recurrent group for ADC in 3, 6, 12 months after treatment:(1.128 ± 0.179) × 10-3 and (1.358 ± 0.145) × 10-3mm2/s, t=5.567,P<0.01;(1.164 ± 0.174) and (1.450 ± 0.102) × 10-3mm2/s, t=7.310,P<0.01;(1.107 ± 0.180) × 10-3 and (1.584 ± 0.125) × 10-3mm2/s, t=11.189,P<0.01;respectively. Take 1.29 × 10-3 mm2/s,1.32 × 10-3mm2/s,1.37 × 10-3mm2/s respectively in 3, 6, 12months after treatment as the diagnostic threshold to predict tumor recurrence. The sensitive , specificity, and accuracy were (83.3%, 73.7%, 77.4%), (83.3%, 89.5%, 87.1%), (100.0%, 94.7%, 96.3%).Conclusions Both DWI and ADC value are important for diagnosing and predicting recurrent NPC after radiotherapy treatment, DWI and ADC can be used to regular follow-up after radiotherapy, to further improve the rate of early diagnosis of recurrent NPC.

Objective To summarize the CT and MRI features of radiation-induced sarcoma (RIS) after radiotherapy in patients with nasopharyngeal carcinoma (NPC).Methods From January 1997 to October 2012,a total of 73 NPC patients with RIS after radiotherapy were confirmed by pathology.The clinical data and imaging findings (CT and MRI findings) were retrospectively reviewed.Of the 73 patients,43 underwent CT examination,24 underwent MRI,and the remaining 6 underwent both CT and MRI scans.Results Fibrosarcoma [45.3％ (33/73)] was the most frequently histologic type,followed by osteosarcoma[31.5％ (23/73)] and malignant fibrous histiocytoma [9.6％ (7/73)].The top three common sites were maxillary sinus [26.7％ (20/73)],followed by the neck soft tissue [17.8％ (13/73)] and mandible[13.7％ (10/73)].The main characteristics of the RIS on CT and MRI were soft tissue masses[78.1％ (57/73)] with an irregular shape and ill-defined margin,or rounded masses with welldefined margin [21.9％ (16/73)].CT of 49 patients showed masses with isodensity or mixed density on precontrast CT.MRI of 30 patients showed lesions with isointensity signal on T1WI and intermediate signal intensity on T2WI.On post-contrast images,65.8％ (48/73) tumors showed markedly homogeneous or inhomogeneous enhancement,23.2％ (17/73) lesions showed moderate enhancement,and 11.0％ (8/73) masses showed mild enhancement.Among the 23 patients with radiation-induced osteosarcomas,78.3％ (18/23) presented tumor bone formation.Conclusions RIS has a characteristic imaging features.Clinical history,tumor sites and serial imaging follow-up are necessary for early detection of RIS in patients with NPC.

Objective To characterize the features of Nasopharyngeal non-Hodgkin's lymphoma (NHL) on MR imaging and find the main points to differentiate it from the other nasopharyngeal tumors.Methods The MR images of 41 patients with pathologically and immunohistochemically proven nasopharyngeal NHLs were reviewed retrospectively. Images were assessed by the size, invasive extent,signal intensity of primary nasopharyngeal tumor, and the distribution of cervical lymphadenopethy. The difference of regional tissues invasion and cervical lymphadenopathy distribution between the patients with B-cell NHLs and the patients with T-cell or NK/T-cell NHLs were analyzed by Pearson's Chi-Square test or Fisher's exact test Results Of the 41 patients, 26 patients had mature B-cell lymphoma, two patients with mature T-cell Iymphoma, and thirteen patients showed Nature killer/T-cell lymphoma in nasopharynx. MRI revealed that NHLs of nasopharynx can be showed as thickening of nasopharyngeal mucosa and (or) lumps in nasopharynx, which were slightly hyper-intensity on T2-weighted images, and intermediate signal intensity (similar to muscle) on T1 -weighted images, with mild or moderated enhancement following contrast medium administration. Twenty four cases had symmetrical disease of all walls of nasopharynx, and 17 cases had unsymmetrical tumor. Of all cases, 5 cases had superficial ulcerations, 9 cases had exceed nasoharynx invasion spreads superficially along the mucosa, 23 cases had invasion of lingual and (or) palatine tonsils,20 cases showed invasion of parapharygeal muscles, 12 cases suffered from skull base bone infiltration,25 cases had retropaharyngeal lymphadenopathy, and 27 cases had cervical lymhadenopathy. Patient with nasopharyngeal Nature killer/T-cell lymphoma had a higher incidence of exceed nasopharynx invasion,parapharyngeal structures invasion, and superficial ulcerations (the cases were 8, 11, 4 in patient with T-cell or N K/T-cell lymphoma, and 4, 10, 1 in patients with B-cell lymphoma, respectively). Patients with nasopharyngeal B-cell lymphoma had a higher incidence of inasion of lingual and (or) palatine tonsils.Conclusions Nasopharyngeal NHL is a homogeneous tumor that tends to diffusely involve all walls of the nasopharynx and spread in an exophytic fashion to fill the airway, rather than infiltrating into the deep tissues. Different pathological types of nasopharyngeal NHLs have some different appearance on MRI between each other. A large tumor in nasopharynx that fills the nasopharynx cavity, with no or minimal invasion into deep structures, but with invasion extend down into the lingual and(or)palatine tonsils, may suggest the diagnosis of nasopharyneal NHL.

Objective To evaluate the signal changes of the skull base after salvage surgury via endoscopic transnasal approach for local recurrent nasopharyngeal carcinoma.Methods Twenty patients with nasopharyngeal carcinoma after radiation failure underwent nasophargeryngectomy via an endoscopic transnasal approach were selected from April 2006 to December 2011,including 16 males and 4 females with 31 to 67 years old.Each patient had previously received irradiation and experienced recurrence after 8 to 83 months of completed irradiation.All patients underwent MRI no more than 2 weeks before the salvage surgery and were subjected to repeat MRI scans 2 weeks,3 months,6 months later and semi-annually thereafter,with the follow-up time of 6 to 45 months(median 18 months).A two-sided Chi-square test was used to compare the signal changes and the tendency of changes on all presurgical and postsurgical MR images.Results The MRI signal changes were detected at 92 sites of skull-base between 2 weeks and 3 months after the surgery,which was hypointense on T1 WI with moderate to marked contrast enhancement.In the follow-up period,the signal abnormalities at 36 sites of skull base had resolved or restored to the normal,and 34 sites remained stable,while in 22 sites,the MR signal changes became more obvious.The skull base bones adjacent to the region of the resection were more likely to show signal changes than nonadjacent areas (72 vs.20,x2 =33.128,P ＜0.01).The signal changes were more common on the ipsilateral skull base to the recurrent tumor in contrast to the contralateral skull base (68 vs 24,x2 =21.182,P ＜ 0.01).Conclusions The skull base signal changes after salvage surgury via endoscopic transnasal approach for local recurrent nasopharyngeal carcinoma,and it occurs in specific location.Most of sites tend to resolve or be stable at the follow up.

Objective To compare the diagnostic efficacy of bone scintigraphy and MRI on vertebral metastases in patients with nasopharyngeal cancer (NPC). Methods Forty-seven patients of NPC and clinically confirmed metastatic disease in spine underwent bone scintigraphy and MR examination. The number of involved vertebri diagnosed with two methods were calculated and compared retrospectively. Results A total of 187 vertebral metastases were found in 47 patients, among which 153 (81.82%) were detected with bone scintigarphy and 182 (97.33%) were diagnosed with MRI (χ~2＝23.758, P＝0.000). Conclusion Compared with bone scintigraphy, MRI is superior in detecting vertebral metastases from NPC, and can be used as the first choice for the early diagnosis of spinal metastases from NPC.

Objective To study the imaging features of Kimura disease to improve diagnostic ability prior to surgery.Methods The clinical manifestations and CT and MR findings of 11 patients with histologically confirmed Kimura disease were retrospectively analyzed.All 11 tumors originated from (or involved)the parotid region in 7 cases, the maxillofacial region in 2 cases, the palate in one case and the groin in one case.Clinically, the lesions showed asymptomatic tumors with the mean clinical course over 2 years.The increase of cosinophilic granulocyte was found in all 11 cases.Results On CT and MRI,5 patients were single masses and others were muhi-nodular masses.The smallest lesion was 6 mm×3 mm,and the largest lesion was 60 mm × 34 mm.The lesions were almost ill-defined in the subcutaneous tissue,especially 10 locating underlying superficialfascia in head and neck.On CT,the lesions showed homogeneous hypodense to the muscle in 9 patients.The lesions appeared isointeuse signal or slightly hypointense on MR T1WI and slightly hyperinteuse on T2WI in 3 patients.All lesions revealed moderate or marked, and homogeneous or inhomngeneous enhancement.Regional lymph nodes (eight cases in the maxillofacial region and one in the groin) enlarged without necrosis and fusion, and with marked enhancement.Conclusion The clinical and imaging findings of Kimura disease have some characteristics, the diagnosis can be made combined with the laboratory examination.

Based on the development requirements of the Clinical Skills Teaching Center of modern hospitals and the needs of clinical practice teaching, the innovative human resource management model is applied to the management of the clinical skills teaching team of Bengbu Medical College, thereby promoting the fine teaching of the business in the new era.The construction of an excellent teaching team has achieved obvious initial results.This research analyzes specific management measures in combination with the actual situation, and aims to provide a reference for improving the quality of clinical skills teaching teams in Bengbu Medical College, and even promoting the reform and management of clinical skills teaching teams in the country.

Objective To explore whether Yes-associated protein(YAP)affects occurrence and progression of liver fibrosis by regulating epithelial-mesenchymal transition(EMT).Methods In a 8-week-old C57BL/6 mouse model of CCl4-induced liver fibrosis,the effect of verteporfin(a YAP inhibitor)intervention was assessed with HE staining and by detecting liver biochemistry and expressions of YAP and EMT-related genes using immunohistochemistry and Western blotting.Transcriptome and proteomic sequencing and informatics analysis were used to investigate the main downstream pathways of YAP in liver fibrosis.Serum levels of YAP,N-cadherin,vimentin and Twist were examined in 60 healthy individuals,60 patients with chronic hepatitis B(CHB),and 60 patients with HBV-related liver cirrhosis.In another 24 C57BL/6 mice,the effects of Twist inhibitor alone or in combination with harmine(a YAP activator)on CCl4-induced liver fibrosis were evaluated by histopathological examination and Western blotting.Results The mouse models of liver fibrosis showed obvious structural damages of the liver lobes with formation of pseudolobules,and verteporfin treatment significantly improved these pathologies and lowered plasma ALT and AST levels of the mice.Transcriptome and proteomic sequencing and informatics analysis suggested that N-cadherin and Twist were differentially expressed in liver fibrosis in close correlation with YAP.Inhibition of YAP obviously downregulated hepatic N-cadherin and Twist protein expressions in the mice with liver fibrosis.In patients with CHB and liver cirrhosis,serum levels of YAP elevated obviously with the severity of liver fibrosis and were significantly correlated with N-cadherin,vimentin and Twist levels.In mice with liver fibrosis,inhibiting Twist effectively improved liver inflammation and fibrosis,while the combined treatment with YAP activator worsened hepatic collagen fiber deposition and increased hepatic YAP and α-SMA expressions.Conclusion EMT is an important pathogenic mechanism of liver fibrosis,and inhibiting YAP can alleviate liver fibrosis by reducing EMT.