Clinical practice is a key step that students take to become doctors.This paper does research in clinical teaching methods for ophthalmology through analyzing current problem of clinical practice in ophthalmology.In the clinical teaching,we should strength the building up of clinical teachers,stimulate students' interest and activity,take PBL(problem-based learning) into teaching method,make use of the principle of optimization medical care and the evidence-based medicine in clinical practice teaching,strength medical students' legal consciousness and cultivate capability of building up cooperative doctor-patient relationship,and improve quality of clinical teaching.

Objective To evaluate the improvement of diagnostic accuracy with background region of interest(ROI)rectification for 99mTc-DTPA renography in patients with GFR≤plasma sampling method). Methods Thirty-three patients(age＞20 years,male/female=13/20)dose of 111 MBq/0.5 ml of 99mTc-DTPA was injected into an antecubital vein.The background ROI was selected below the kidney(Gates method,method a)or around the kidney(method b),then these two different GFR(GFRa,GFRb)were automatically estimated by computer.Meanwhile,3 ml blood samples were collected 2 h and 4 h after injection respectively,and radioactivity of 1 ml plasma was measured.GFR was calculated by dual plasma sampling method(GFRp)and the results were all standardized with the body surface area.The accuracies and correlations of GFRa and GFRb were compared to GFRp respectively. Results The correlation coefficients were ra=0.602 and rb=0.834.The median of difference of GFRa and GFRb was 8.33,-4.41.The median of absolute difference of GFRa and GFRb was 8.33,4.49.The accuracies within±15%,±30%and±50%of GFRa were 24.2%,30.3%and 48.5%,and those of GFRb were 33.3%,51.5%and 81.8%.Conclusion The background ROI around kidney can obviously improve the diagnostic accuracy of 99mTc-DTPA renography in patients with severe renal insufficiency.

Objective To investigate the long-term curative effect of the radiotherapy combined uterine arterial interventional chemoembolization for cervical cancer.Methods Records of 632 patients with cervical cancer stage Ⅱ-Ⅳa proved by pathology in Lanzhou Command General Hospital from January 1st,1999 to August 31st.2009 were retrospective analysed.One hundrand and twenty-six cases of them were treated with radical radiothempy combined uterine arterial interventional chemoembolization(arterial chemoembolization+radiotherapy group).506 cases of them were treated with radical radiotherapy only (radiotherapy group);the evaluation of the late radiation injury was done,according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer(RTOG/EORTC)advanced radiation injury criteria.Prognosis and complications were compared between two groups,relative risk factors of radiothempy complications were identified by method of logistic regression.Results (1)Survival:the total survival mtes of 1-year,2-year,5-year and 8-year were 94.4%,82.3%,48.8%,29.1%,respectively.The survival rates of arterial chemoembolization+radiotherapy group were 96.0%.82.1%,37.2%,25.7%,while the survival rates of radiotherapy group were 94.1%,80.8%,51.1%,31.5%,in which there were significant differences between two groups (x2 = 0.009, P= 0.993; x2 =0. 158, P =0.691;X2 =11. 197,P=0. 001;x2 =9. 649,P =0.002). During the follow-up period, the rate of recurrence and metastasis in arterial chemoembolization + radiotherapy group were 77. 0% (97/126), while 73. 3% (371/ 506) in radiotherapy group ( x2 = 0. 705,P = 0. 401). (2) Radiotherapy complications and relative risk factors; the total incidence of tardive bladder injury higher than RTOG/EORTC stage II was 5.5% (35/632), while it was 11. l%(14/126)in arterial chemoembolization + radiotherapy group, 4.2% (21/506) in the radiotherapy group(x2 =9.344,P =0.002). The results of logistic regression showed that the uterine arterial interventional chemoembolization was relative risk factors of the tardive bladder injury ( x2 =6. 440, OR = 2. 869,P=0. 011). Conclusions Compared with the simple radiotherapy, there are a similar short-term survival rate and significant poor 5-year, 8-year survival rate in the patients treated with the uterine arterial interventional chemoembolization combined with radiotherapy, which also may be strong dangerous factor for the occurrence of tardive bladder injury. The results shown that the uterine arterial interventional chemoem bolization do not recommend to be routine adjuvant therapy for the radical radiotherapy of cervical cancer.

BACKGROUND:Many studies have confirmed that recombinant human bone morphogenetic protein 2 plays a very important role in bone formation and fracture healing, but recombinant human bone morphogenetic protein 2 alone implanted is prone to diffusion and degradation, which is unable to play a persistent role in new bone formation. OBJECTIVE:To explore the effect of recombinant human bone morphogenetic protein 2 composite bone in the rabbit lumbar fusion. METHODS:Thirty New Zealand white rabbits were selected to make posterior lumbar intertransverse fusion models, and then were randomly divided into three groups, in which, L5-6 intertransverse implantation of autologous iliac bone, al ogeneic bone and recombinant human bone morphogenetic protein 2 composite bone (recombinant human bone morphogenetic protein 2 and al ogeneic bone complex) was done respectively. At 6 weeks after implantation, gross observation, X-ray examination and histological observation were performed. RESULTS AND CONCLUSION:Fusion rate and percentage of new bone area were higher in the composite bone group than the autologous iliac bone and al ogeneic bone groups (P<0.05);the tensile strength was lower in the al ogeneic bone group than the other two groups (P<0.05), but there was no difference between these two groups except the al ogeneic bone group. X-ray films showed cal us formation in the implanted region of the three groups. In the autologous iliac bone group, a large amount of cartilage tissues formed along with a smal amount of bone trabeculae and a certain amount of woven bones. In the al ogeneic bone group, the implant was covered with a large amount of fibrous tissues, bone island was seen and there was also a smal amount of bone trabeculae and cartilage tissues. In the composite bone group, a great amount of bone trabeculae and cartilage tissues were visible to form woven bone and cortical bone. These findings indicate that the recombinant human bone morphogenetic protein 2 composite bone can obtain good effect in the rabbit lumbar fusion.

BACKGROUND:Posterior maleolar fracture is an important factor affecting the prognosis of ankle fractures. Posterior maleolar fracture often caused by high energy trauma. Using what kind of fixation and fixation materials biomechanics, and how to embed has become a current research hotspot. OBJECTIVE:To compare the clinical outcomes of different fixation materials on posterior maleolar fracture, and analyze the effect of different fixation methods on biomechanical outcome of posterior maleolar fracture fixation, so as to provide a basis and reference of selecting the best fixation for the clinical treatment of ankle fracture. METHODS: The relevant literature included by PubMed database and the China National Knowledge database from the year of 1976 to 2015 were retrieved by the first author through computer. English key words are “Ankle fracture; internal fixation; biomechanics; biocompatibility”, Chinese language search terms are “posterior maleolar fracture; internal fixation; biomechanics; biocompatibility”. Summarize the most commonly used metal fixation materials and absorbable content materials. The clinical commonly used metal fixation materials including bone plate and screws, absorbable fixation materials such as biodegradable material polylactic acid, polyethylene plastic ester, polylactide gum ester, etc. The biomechanical properties were analyzed. RESULTS AND CONCLUSION: The new locking screw can withstand more buckling and shear force. Lag screw has a tapping action, and the puling was stronger after tapping, but for patients with osteoporosis, the pressure effect of screw on fracture fragments was limited, the strength was not enough, at this time, locking plate should be used. Locking plate has a greater stability and higher confrontational feature to bending stress, less likely to pul out. Steel coupling screw provides better stability. To avoid secondary removing of the fixation, stress protection after fixation and other shortcomings after the metal material fixation fracture healing, the strength of the absorbable fixation material made by biodegradable material polylactic acid, polyvinyl acetate glue and polypropylene plastic ester after high temperature and pressure processing was increased. Absorbable fixation material may overcome the adverse effects associated with metal fixation, such as imageological examination, secondary implant removal. These results show that the mechanical properties of the absorbable screws are more closer to human bone, no surrounding bone vulnerability due to stress shields, no osteoporosis occurs, and can degrade in the body, but its fixation strength is stil less than the traditional fixed screw and bone plate. We should choose a suitable fixation material according to the forces of fracture site and the size of the fracture fragments.

Objective:To observe and compare the clinical effect of single-incision and two-incision posterior chamber phakic intraocularlens implantation in the correction of extreme myopia.Methods:40 cases(80 eyes) of patients with extreme myopia underwent conventional two-incision posterior chamber phakic intraocularlens implantation in our hospital from January 2011 to June 2013 were selected as the control group and 40 cases(80 eyes) underwent single-incision posterior chamber phakic intraocularlens implantation from July 2013 to January 2016 were selected as observation group.The open hole before and after operation,best corrected visual acuity of vision,operation safety,effectiveness index,diopter (column mirror,equivalent ball for eyeglasses),intraocular pressure,ECD,anterior chamber depth and occurrence of complications were compared between two groups.Results:The uncorrected visual acuity (UCVA) of both groups at 6 months after operation were significantly higher than those before operation (P＜0.05),which was significantly higher in the observation group than that of the control group (P＜0.05);The operation safety and effectiveness index of observation group were significantly higher than those of the control group (P＜0.05);The cylinder and spherical equivalent degree of both groups at 6 months after operation were significantly better than those before operation(P＜0.05),which was significantly better in the observation group than that of the control group(P＜0.05).The corneal endothelial cell counts(ECL) of control group after operation was significantly lower than that before operation (P＜0.05),and no significant difference was found in the ECL of observation group before and after operation (P＞0.05).The ECL of observation group after operation was significantly higher than that of the control group (P＜0.05);The incidence rate of complication in observation group was significantly lower than that of the control group (P＜0.05).Conclusion:Compared with two-incision operation,the single-incision posterior chamber phakic intraocularlens implantation had remarkable clinical effect in the correction of extreme myopia with higher security.

Objective To explore the effect of low constant direct current (LCDC) in the medullary cavity on repairing of rabbit radial defect as to evaluate its clinical value. Methods DBX was put into the segmental osteoperiosteum defect of rabbit bilateral radius. The rabbits were divided into 2 groups: group A (subject group) with the defects stimulated by LCDC and group B (control group) with the defects left untreated. In week 2,5 and 9, 4 animals from each group were put into death, and the radius was taken for study using photograph, electron microscope, histological & morphologic technique, and the contents of the Calcium (Ca) and ALP were determined. Results Compared with group B, the healing of group A was better. The contents of Ca and ALP increased obviously in week 2 (P

Objective To analyse the effectiveness of the preoperative 3-dimensional conformal radiotherapy for large nephroblastoma up to 10 centimeters in diameter,and to investigate more effective preoperative therapies for intermediate and advanced nephroblastoma.Methods 32 cases of nephroblastoma were treated with preoperative radiotherapy with a dose fractionation as follows:150-200 cGy/fraction,5 fraction/week,the total dose of 1 000-2 000cGy,the mean dose of 1 600 cGy.During the radiotherapy,the B ultrasonic examination and CT were performed weekly to measure the variation of tumor volumes.The time of operation were determined based on the overall health status of patients,the shrinkage of tumor,and adhesions between tumor and adjacent vital organs.Radiontherapy was terminated one week before operation.4 patients who were found tumor adhered to normal tissues around kidney during operation were placed silver clip,and were given postoperative radiotherapy with additional dose of 1 000-2 000 cGy and the mean dose of 1 200 cGy.Results The median tumor reduction rate was 37 ％.The effective rate of preoperative radiotherapy was 100 ％.The complete resection rate was 87.5 ％.2-years tumor-free survival rates was 84.4 ％ and 5-years was 78.1％.There was no surgery-related death.Conclusion Preoperative 3-dimensional conformal radiotherapy reduces tumor volume,and raises resection and survival rate.

The coronal process of ulna is an important stable structure in front of the elbow joint, which is composed of the tip of the coronal process, towering tubercle and anterior medial face. The fracture of the coronal process is often accompanied by the fracture and dislocation of the elbow joint, which leads to the instability of the elbow joint. The coronoid process has the advantages of small size, special shape, complex surrounding soft tissue structure, and plays an important role in the stability of the elbow joint. The selection of safe, minimally invasive and well exposed surgical approach is a necessary condition for safe and effective internal fixation. The choice of surgical approach must comprehensively consider the concomitant injury and choose the best surgical approach. This article mainly describes the normal anatomical structure of the coronal process and around the elbow joint, analyzes the biomechanics and stability of the coronal process in the elbow joint, and reviews the latest progress in surgical treatment.

Objective To evaluate 18F-FDG hPET/CT in the diagnosis of postoperative recurrence and metastasis of colorectal cancer. Methods GE HAWKEYE coincidence SPECT was carried out in 81 colorectal cancer patients with suspected recurrence or metastasis after intravenous injection of 259 ~ 298 MBq (7-8 mCi) 18F-FDG. The acquired data were reconstructed using iterative algorithm and attenuation-corrected X-ray. The results were compared with the final diagnosis established by histological examination of resected specimens、and clinical follow-up. Results The sensitivity, specificity, positive predictive value (PPV)and negative predictive value(NPV)was 93% (57/61)、80% (16/20)、93% (57/61)、80% (16/20) for 18F-FDG hPET/CT respectively. For conventional CT the sensitivity, specificity, PPV and NPV was 67% (37/55)、73% (19/26)、84% (37/44)、51% (19/37) respectively; 18F-FDG hPET/CT detected 91 recurrent or metastatic lesions whereas only 46 lesions were detected by conventional CT in 65 patients. Conclusions 18 F-FDG hPET/CT has unique value in the diagnosis of recurrence and metastasis in postoperative colorectal cancer patients which was superior to conventional CT. Combined 18 F-FDG coincidence imaging with localizing CT improves the detection and localization of postoperative recurrence and/or metastasis in colorectal cancer patients.