Embryonic stem cells undergo extensive self-renewal and have the capacity to differentiate along multiple cell lineages.Research on totipotency and directional differentiation of embryonic stem cells in order to treat intractable disease,such as cancer,heart failure,atherosclerosis by tissue regeneration and cell transplantation are investigated.Epigenetic modification,including DNA methylation,chromatin restructure,and non-coding RNA-mediated regulatory events,regulate the differentiation of embryonic stem cells without detectable genetic changes.These mechanisms are often associated with starting-up and maintenance of epigenetic silence.The achievement and focuses on the molecular mechanism of embryonic stem cells during directional differentiation regulated by epigenetic modification are reviewed.

For many years, researches on Cytochrome P450 had been focused on their roles in exogenous drugs and poisons metabolism. In fact, Cytochrome P450 also showed significant importance in conversion of endogenous materials, such as steroids, cholesterol, hormones, fatty acid and vitamins. Among such Cytochrome P450 enzymes, CYP2J2 mainly metabolizing arachidonic acids into epoxyeicosatrienoic acids, was detected recently in human beings. The association of CYP2J2 with diseases attracts many researchers great interests. This article briefly summarized those researches of homo sapiens CYP2J2 on its distribution, physical significance, coding gene and mutants of gene as well.

Objective To explore the value of ultrasound in diagnosis and differential diagnosis of pancreatic mucinous cystade‐noma and serous cystadenoma .Methods Data of tumor features of sixty seven cases of pancreatic cystadenoma ultrasonographic was retrospectively analyzed .The tumor location ,tumor size ,tumor boundary ,tumor shape ,cavity number and calcification were re‐corded .Then all the data was statistically analyzed .Results Pancreatic cystadenoma occured mostly in middle‐aged women ,there was no significant difference between pancreatic mucinous cystadenoma and serous cystadenoma of the pancreas in age ,gender ,le‐sion location ,lesion size ,shape ,boundary ,cystic wall ,cystic wall nodules(P>0 .05) ,while there were significant differences in with and without clinical symptoms ,cavity number ,diameter of the largest cyst and calcification(P<0 .05) .Conclusion Ultrasonic man‐ifestations of pancreatic cystadenoma has certain characteristics ,when there are clinical symptoms ,cavity number is less than 6 , maximum sac diameter is bigger than 2 cm and there is marginal calcification ,it tends to mucinous cystadenoma;when there is no clinical symptoms ,cavity number is equal to or more than 6 ,maximum sac diameter is equal to or smaller than 2 cm and there is cen‐tral calcification ,it tends to serous cystadenoma .

Objective To investigate the conventional ultrasonic and elastographic characteristics of papillary thyroid micro-carcinomas(PTMC) suffered in normal and Hashimoto's thyroiditis(HT).Methods A total of 227 patients with 249 nodules that were confirmed by surgery or biopsy were included in this study.The cases were divided into normal group and HT group.All patients underwent conventional ultrasound and elastography (static pressure).The sonographic characteristics and strain ratio (SR) value were evaluated.Results In the normal group,the ratio between male and female was 1 ∶ 2.9,while in HT group,it was 1 ∶ 11,which was significant different between the two group (P =0.002).Sonographic characteristics that had no significant difference between the two groups (P ＞0.05) include:boundary,shape,vertical and horizontal ratio,halo,echogenicity,calcification,posterior shadowing,vascularity on color Doppler ultrasonography.The strain ratio value was statistically different between the two groups (P =0.034),with 3.44 ± 1.03 in normal group and 3.13 ± 1.13 in HT group.Conclusions The conventional ultrasonographic features of PTMC were similar in both normal thyroid and HT.However,females suffering HT were more susceptible to PTMC,and the strain ratio value of PTMC concomitant HT decreased.

The sonographic features of male breast lesions, which underwent ultrasound examination in our hospital for the past 10 years, were retrospectively analyzed. Sonographic features of these lesions were standardized as BI RADS image lexicon. The differences in ultrasonic malignant signs were assessed between the benign and the malig nant diseases. Between the two groups, incomplete boundary was statistically different. The specificity was above 95% within the two groups in terms of speculated margin, echogenic halo, calcification, axillary lymphadenopathy, thickening of skin and eccentric of mass to the nipple. High-frequency sonographic examination has a high level of differential diagnosis for male breast lesions.
Breast ; pathology ; Breast Neoplasms, Male ; diagnosis ; diagnostic imaging ; Diagnosis, Differential ; Humans ; Male ; Retrospective Studies ; Sensitivity and Specificity ; Ultrasonography, Mammary

Objective To evaluate efficacy on treatment of acute iliofemoral lower extremity deep venous thrombosis with thrombectomy and pharmacological thrombolysis or pharmacological thrombolysis alone. Methods The clinical data of 175 cases of lower extremity iliofemoral deep venous thrombosis wereanalysed retrospectively. Patients were divided into thrombectomy group and thrombolysis group. There were 85 patients treated by thrombectomy, among these patients there were 46 with common iliac vein occlusion or stenosis. According to state of illness suitable treatment was selected, urokinase and low molecular weight heparin were given after operation. The other 90 patients were treated by pharmacological thrombolysis only,including urokinase and low molecular weight heparin. Results No significant differences were found in age, course of disease, swelling and associated diseases between the two groups before treatment (P ＜0. 05); After 1 month of treatment the circumference difference between bilateral limbs was reduced from (4.6±1.6) cm to (0.8 ±0.5) cm in operation group,and declined from (4.0±1.9) cm to (1.8 ±1.3) cm in thrombolysis group. The cure rate was 71.8% (61/85) in thrombectomy group and 38.9% (35/90) in thrombolysis group. 64.6% patients were followed up for an average of (28 ± 11 ) months.After 12 months of treatment the circumference difference between bilateral limbs was (0.4 ± 0.3 ) cm in thrombectomy group and ( 0.9 ± 0.7 ) cm in thrombolysis group respectively. The cure rate was 86.0% (49/57) in thrombectomy group and 53.6% (30/56) in thrombolysis group. In surgical group the incidence of deep venous thrombosis sequelae was less than in thrombolysis group( P ＜0. 05 ). The incidence of venous valve dysfunction in thrombectomy group was less than in thrombolysis group (P ＜ 0.05 ).Conclusions Thrombectomy and pharmacological thrombolysis was more effective than pharmacological thrombolysis alone in the treatment of acute iliofemoral deep venous thrombosis.

Objective To set up an objective criterion for BI-RADS assessment.Methods The breast sonograms of 1 938 female cases were retrospectively studied which had been confirmed by pathology from January to September 2011 and 2012 January.1 660 cases during 2011 were model cases,and the importance of each single feature in distinguishing between benign and malignant was obtained with Chi square and OR value.A detailed criterion of BI-RADS assessment category was set up based on US-BI-RADS.Results Eighteen of 24 lexicons were statistically significant distinguished between benign and malignant breast masses(P ＜ 0.05).The lexicons were divided into major suspicious signs,middle ones and minor ones assigned 3 points,2 points and 1 point,and a scoring model was established as follows:Score =3 * (X1 + X2 + … + X6) + 2 * (X7 + X8 + … + X12) + (X9 + X10 + … + X18).Based on BI-RADS,the positive predictive value of model cases was 1.5％,6.9％,22.1％,62.5％,96.1％ followed by category 3,4A,4B,4C and 5,and it was 1.4％,3.4％,21.1％,69.4％,92.7％ in test cases.Conclusions The scoring model could be useful for BI-RADS final assessment more objectively,and could make it more convenient to predict the risk of breast cancer.

ObjectiveTo evaluate the mid- and long-term efficacy of subfascial endoscopic perforator surgery (SEPS)in the treatment CEAP classification C4 - C6 of primary chronic venous insufficiency(CVI). MethodsClinical data of 82 cases of chronic venous insufficiency were analysed retrospectively. According to operative method adopted,patients were divided into group A in which perforator veins were ligated under subfascial endoscopic surgery (SEPS group ),and group B in which perforator veins were not ligated (non-SEPS group).Diagnosis was established by clinical symptoms,color Doppler or ascending venography in all patients.Postoperatively patients were followed up regularly.The clinical outcomes between different surgicalmethods in two groups were assessed byCEAP clinical classification,CEAP clinical symptom scores,cumulative ulcer healing rate and cumulative ulcer recurrence rate.ResultsNo significant differences were found in CEAP clinical classification,CEAP clinical symptom scores between the two groups preoperatively ( P ＞ 0.05 ). There were significant differences in CEAP clinical classification such as edema,lipodermatosclerosis,venous ulceration between the two groups on 2 years postoperatively (P ＜ 0.05 ).The amount of swelling limbs,healed ulceration,active ulceration in group A was less than group B (P ＜ 0.05 ) on 3' and 5' years postoperatively.Significant differences were found postoperatively in total clinical symptom scores between group A and B.Clinical symptoms such as swelling,lipodermatosclerosis,ulcer healing in group A relieved more markedly than group B ( P ＜ 0.05 ).The median healing time of ulcers was 2.3 and 3.7 months respectively in group A and B.Log-rank test on group differences was sensitive to long-term cumulative ulcer healing rate ( x2 =4.063,P =0.044).But Breslow test on group differences was sensitive to early cumulative ulcer healing rate ( x2 =5.471,P =0.019).Cumulative ulcer healing rate in group A was significantly higher than in group B postoperatively (P ＜ 0.05 ).The cumulative ulcer recurrence rate in group A was significantly lower than group B (P ＜ 0.05).ConclusionsSuperficial vein resection combined with perforator vein ligation significantly enhanced clinical efficacy,accelerated ulcer healing and decreased mid- and long-term ulcer recurrence rate.

Objective To compare complication between clamp harmonic scalpel and traditional pattern of bipolar electric knife in open thyroidectomy.Methods Patients undergoing open thyroidectomy from Jan.2009 to Dec.2010 in Thyroid Surgery Department of Sun Yat-sen Memorial Hospital of Sun Yat-sen University were analyzed retrospectively.Patients fell into 2 groups according to operative pattern:633 cases in clamp harmonic scalpel group and 587 cases in bipolar electric knife group.Complications such as intraoperative and postoperative blood loss,reooperative hemostatic rate,transient or permanent recurrent laryngeal nerve palsy,transient or permanent hypocalcaemia,and infection rate were compared.Results Compared with bipolar electric knife group,intraoperative and postoperative blood loss,reoperative hemostatic rate,transient recurrent laryngeal nerve palsy and transient hypocalcaemia in clamp harmonic scalpel group were significantly lower:(21.0 ±0.7)ml vs (10.0±0.3) ml,(31.0±1.1) mlvs (12.0±1.4) ml,1.53％ vs0.47％,2.39％ vs0.95％,1.87％vs 0.63％,and 3.58％ vs 1.73％ respectively(P ＜0.05).There was no significant difference in complications of permanent hypocalcaemia,permanent recurrent laryngeal nerve palsy and infection rate for the 2 groups:0％ vs 0％,0％ vs 0％,and 0.68％ vs 0.63％ respectively ( P ＞ 0.05 ).Conclusions Compared with traditional pattern of thyroidectomy,complication rate in clamp harmonic scalpel is significantly lower.Thyroidectomy by clamp harmonic scalpel is a safer operative pattern and worth to be popularized.

ObjectiveTo discuss the management of chronic thyroid abscess in children. MethodsThe diagnosis and management of 16 children with chronic thyroid abscess admitted from Jul. 2007 to Jun. 2010 in Department of Thyroid Surgery of Sun Yat-ssn Memorial Hospital of Sun Yat-sen University were retrospectively analyzed. All the patients were checked by Doppler ultrasound. ResultsOf the patients, 6 were males and 10 were females. The time of onset was from 3.2 years to 8.5 years, with 4. 6 years as the median. Hypoechoic or mixed echoic lesions in thyroid were seen on Doppler ultrasound scan in all patients. Abscess was found on the left side of thyroid in 11 cases (68.8％), and on the right side in 5 cases (31.2％). Abscess in 12 cases (75％) occupied the whole thyroid and began encroaching the adjacent tissues. Hypodermic fistula was found in 7 cases (43.75％). 12 cases (75％) underwent part resection of thyroid gland, and 4 cases (25％) underwent total resection of thyroid gland and debridement. All patients recovered and no complication like vocal hoarseness occurred. No recurrence happened within the follow-up of 3 months to 5 years. ConclusionsThe effective diagnosis of chronic thyroid abscess in children is to perform Doppler ultrasound scan of thyroid gland before operation. Abscess and fistula resection, partial or total resection of the affected side of thyroid gland are needed. Wound drainage and postoperative antibiotc are also helpful.