That there are so many difficulties in both of teaching and learning electrocar-diogram(ECG)is the characteristics in teaching and studying ECG. The following ways are the ef-fective methods of improving effects of classroom teaching of ECG:emphasizing the importance of ECG in clinical work at the beginning of the lecture on ECG in order that the students can understand the necessity of studying ECG and make up their mind to study ECG well;studying the teaching contents on ECG seriously and supplement the textbook appropriately;set up the link of discussion and create the condition that teacher and students work altogether;produce the slides with pictures(mainly)and words and give accounts of the pictures mainly;sum up the character-istics of all sorts of abnormal ECG and state the characteristics of presenting ECG simultaneously.

Objective To investigate the CT imaging features of urinary tract ceftriaxone-associated pseudolithiasis.Methods The CT imaging data of three patients with ceftriaxone-associated pseudolithiasis were collected from August,2008 to April,2012.Their data combined with related literatures were used to review CT imaging features of urinary tract pseudolithiasis.Those three patients,including 2 males and 1 female,were 9,21 and 55 years old,respectively.Ceftriaxone sodium was administrated to one patient due to appendicitis and the other two patients due to urinary tract infection.After ceftriaxone treatment,1 case began to have backache and abdominal pain on day 13,1 case presented backache with floc in the urine on day 2 and progressed to anuria,and the other one had cotton-like material in the urine on day 5.Urinary tract high density shadows were found in all patients by CT scan.The patient with anuria was treated with ureteroscopic lithotripsy and percutaneous nephrolithotomy.The other 2 cases were arranged to be followed up with CT scan.In those cases,the CT showed that the high density shadow in one patient disappeared 16 days after drug discontinuation.The high density shadow was significantly reduced 12 days after ceftriaxone withdrawal in the other one.However,no follow-up was performed afterwards.Results All the urinary tract ceftriaxone-associated pseudolithiasis presented the high density shadows on CT,with CT value 47-667 HU.The density of CT results is homogenic,except one ureteral stone.The pseudolithiasis,existed in kidney,ureter and bladder simultaneously,were found in two patients.And the other patient was found that the pseudolithiasis existed in both kidney and bladder.Two cases were accompanied with hydroureter and hydronephrosis and the other case were accompanied with cholecystolithiasis.The multiple renal pseudolithiasis was noticed in 2 cases,which exhibited the nodular shape.And one patient with hydronephrosis presented both sand-like and nodular stones.Ureteral pseudolithiasis was found in 1 case with 4 stones and the other one with 2 stones.In those pseudolithiasis,5 appeared column morphology and one showed nodular shape.The single nodular stone in bladder was found in one case.And the multiple bladder stones were found in 2 cases.Conclusions The CT imaging characters of urinary tract ceftriaxone-associated pseudolithiasis are high homogenic density shadows in multiple parts of bilateral urinary tracts.The ceftriaxone-associated pseudolithiasis is column shape in ureter and sand-like or nodular shape in kidney and bladder.

Purpose:To investigate the toxicities and res po nse of liver cancers to 3-dimensional conformal radiation therapy (3-DCRT) com bined with Trancatheter arterial chemoembolization (TACE) Methods :The histopathological confirmed liver cancer patients were treated by 3-DCRT co mbined with TACE, all patients received TACE before 3-DCRT The total irradiati on dose is 50 Gy to 58 Gy in daily fractions of 2 Gy Each planning target volu me (PTV) received a minimum of 90% of the prescribed dose Each mean liver dose not reached 30 Gy, V 30 Gy (the percentage of normal liver volume with ra diation dose≥30 Gy) less than 33% Results:Thirty patients were included in this study including 2 1 hepatocellular carcinoma Survivals at 1 year after 3-DCRT were 76%, with a median survival time of 8 months 2 patients developed Grade 1 acute liver toxi city and one patient experienced Grade 2 gastrointestinal complications No pat ient developed Grade 2 or greater liver toxicity Conclusions:The use of 3-DCRT technique for liver cancer is a safe and efficient method O ur experience indicated the total irradiation dose above 58 Gy is feasible in da ily fractions of 2 Gy, if the mean liver dose did not reach 30 Gy and V 30 G y

Objective To investigate the safety and efficacy of placement of self expandable metallic stent within right atrium and inferior vena cava (ICV) in patients with malignant ICV obstruction involving right atrium. Methods There were 5 male patients with advanced hepatocellular carcinoma, aged from 42 to 65 years (mean 56 3 years). The malignancies invaded right atrium and ICV simultaneously, and caused obstruction of ICV. These patients presented symptoms and signs of obstruction of ICV such as hepatomegaly, ascites, edema of lower extremities. “Z” type stainless steel stents (7 5～10.0 cm in length and 2 5 cm in diameter) were selected for these patients. Part (1.0～3.0 cm in length ) of stent was placed in right atrium and the rest was in ICV. Results All of stents were placed successfully and obstructed ICV reopened. The symptoms of obstruction of ICV relieved or disappeared. There were no recurrence of symptoms of obstruction of ICV and any cardiac complication related to placement of stents in follow up period (67～188 days). Conclusion Placement of self expandable metallic stent within right atrium and ICV in treatment of patients with malignant ICV obstruction involving right atrium is one of the safe and effective methods.

Transforming growth factor-β is an important cytokine with various bioactivities, including embryonic development, wound healing, chemotaxis and cell cycle regulation. Epithelial-mesenchymal transition (EMT) is the main pathway of tumor cell to obtain the ability of invasion and metastasis. The TGF-β is the key factor known to induce EMT in cancer cells and plays an important role in the process. In recent years, some progress has been obtained. Some TGF-β inhibitors have approved in the market or in clinical trials. TGF-β inhibitors can play an important role on the treatment of tumors, glaucoma, liver and kidney fibrosis disease and scar repair. Novel TGF-β inhibitors reported in recent years were reviewed in this article.

0.05). Minor hematoma occurred in four patients with transradial approach and in 59 with transfemoral approach (1.46% vs 17.78%, P0.05), and two patients required blood transfusion in group F. None of the patients suffered from pseudoaneurysm, arteriovenous fistula, and ischemia of the hand. Conclusion Coronary angioplasty can be performed safely using the transradial approach with relatively few vascular complications and with better patient′s comfort.

OBJECTIVETo evaluate the effect of taper and inserting angle on stability of micro-implants in type II bone and to provide theoretical evidence for clinical selection of taper and inserting angle.

METHODSThree-dimensional finite element models of type II bone sections and micro-implants were fabricated. They were designed using different tapers (diameter between 1.1 to 1.6 mm, taper between 0 to 0.0625) and different inserting angles ranging from 30 degrees to 90 degrees (30 degrees, 45 degrees, 60 degrees, 75 degrees, 90 degrees). Effects on the maximum von Mises stresses in mandible and micro-implants, as well as on the maximum displacements in micro-implants, were analyzed under an applied 2 N horizontal force.

RESULTSThe inserting angle had a significant effect on stresses and displacements, with lower distribution of stresses and displacements occurring at 60 degrees. The effect of the taper was also related to the inserting angle. The minimum stresses were 5.013 4 MPa (cortical bone) and 25.1310 MPa (micro-implant) in model D at 60 degrees. The displacements of micro-implants were proportional to the taper.

CONCLUSIONThe inserting angle has a significant effect on stability of micro-implants, and the recommended inserting angle is 60 degrees. The influence of taper on the stability of micro-implants is related to the inserting angle. The micro-implant with 0.0375 taper (maximum diameter is 1.6 mm, minimum diameter is 1.3 mm) is more suitable for type II bones.

Objective To evaluate the impact of mesoreetal margin micrometastasis on local recurrence of rectal carcinoma after total mesorectal excision, and the relation between mesorectal margin mierometastasis and local recurrence. Methods Mesorectal margin specimens from 52 cases of rectal cancer after total mesorectal excision were studied by reverse transcriptase-polymerse chain reaction (RT-PCR) to detect the expression of CK20 mRNA. These patients were divided into CK20 mRNA positive and negative group and followed up for 3 years until local recurrence developed. Results In 52 patients with rectal cancer,21 cases were found to express CK20 mRNA in mesorectal margin, the expression rate of CK20 mRNA in Dukes A,B and C was 17% ,30% and 54% (P<0.05), respectively. The positive rate of well differentiated, moderately differentiated, poorly differentiated and undifferentiated carcinomas were 43%, 38% ,40% and 50% ,respectively(P>0.05 ). The incidence of local recurrence in CK20 mRNA positive and negative group was 24% and 3% , respectively. The difference was statistically significant between the two groups (P <0.05 ). Conclusion Detection of mesorectal margin CK20 mRNA as micrometastasis by RT-PCR in rectal carcinoma patients was a sensitive and effective way in predicting local recurrence. It is necessary for patients with positive mesorectal margin CK20 mRNA to undergo postoperative radiotherapy after total mesorectal excision.

Objective To assess and delineate the dosimetric shortcomings of conventional radiotherapy planning,as compared with the three dimensional treatment planning system, and to obtain a better technique in the treatment of lung cancers.Methods Thirteen patients with stage ⅢA ⅢB non small cell lung cancer were chosen in the present study. Using the Cadplan 6.0.8 treatment planning system , three different methods of radiotherapy planning: conventional planning, conventional and conformal planning, and conformal planning were designed for each patient. The total radiation dose was 66 ?Gy and DVHs were used to assess the dosimetric distribution in the gross tumor volume and the surrounding organs at risk. Results No significant dosimetric disparity in the target volume was found among the three designs, according to anticipated therapeatic requirements. The conformity indices were 0.13,0.24 and 0.35 for these three radiotherapy designs. The mean lung volumes which received radiation dose of≥20?Gy were 32%,26% and 25%.The mean maximum dose at the spinal cord were 42?Gy,49?Gy and 33?Gy.The mean esophageal volume which received radiation of ≥50?Gy were 32%,34% and 22%, and the mean radiation dose to the heart were 18?Gy,15?Gy and 12?Gy,respectively. Conclusions Conventional radiotherapy planning is able to meet the demands of dosimetric requirements for radiation treatment of lung cancers. The three dimensional conformal radiation therapy planning system is able to provide superior delivery of high dose to the target volume without inflicting too high a risk to the surrounding normal tissues and organs.