Objective To investigate the distribution and significance of CD20 positive cells in the early human embryo. Methods Distribution and morphology of CD20 positive cells in 10 specimens of human embryo aged from 6 to 7 weeks were brown,and studied with immunohistochemical method. Results 1.CD20 positive cells appeared in the liver of early human embryo.2.The immunohistochemical positive substances were brown,and found chiefly in the nuclei of B cells as unevenly-distributed granules,and were not detected in the cytoplasma and on the cell membrane.Conclusion The accuracy of location and distribution of CD20 positive cells in the nuclei of B cells of early human embryo liver may provide an important clue for further exploration of the functional mechanism of CD20 in the process of B cell proliferation and differentiation.

Medicine is a practical application subject,so medical students should conduct numerous clinical practice to improve operation skills and clinical diagnosis ability The ability of clinical practice is one of most important indicators to evaluate medical education quality.In recent years,medical students have been affected by many kinds of adverse factors,such as new doctor-patient relationship,the medical reform and employment pressure and so on.All these adverse factors will bring a great challenge to the dental clinical teaching.In the new medical situation we need urgently to solve the problems to guide students to improve clinical practice ability and cultivate qualified dental professionals

Objective To evaluate the diagnostic value of computer-aided diagnosis with three-dimensional volumetric measurement in solid pulmonary nodules on follow-up CT. Methods Forty-six patients with 58 solid nodules were evaluated.Each patient underwent chest CT at least twice.The volume, doubling times(DTs) and volumetric growth rates(VGRs) of nodules were calculated with three-dimensional volumetric measurement software. If there were significant statistical differences in DTs between malignant and benign nodules, Nonparametric test was used to make the analysis.If there were significant statistical differences in upper DTs'values between malignant and benign nodules, X2 test was used to make the analysis.Final diagnosis of all nodule were confirmed by pathology or by response to diagnostic therapy or by clinical follow-up.Results The DTs of 13 malignant nodules were <400 days in 12 nodules, with a range from 45 to 465 days (median, 159 days) ; the VGRs ranged from 8% to 329% (median, 30.0%).The VGRs of 45 benign nodules ranged from -38% to 24% (median, 0%).The DTs of 24 benign nodules that increased or not changed in size were >400 days in 22 nodules, with a range from 302 days to 55 158 days (median, 2 704 days); the VGRs ranged from 0 to 24% (median, 6.5%. Twenty-one nodules that decreased in size had the VGRs ranging from -38% to -4% (median, - 16.0%), and the DTs of these nodules could not be calculated by software.There were significant statistical differences in DTs between malignant and benign nodules(P <0.05).Taking 500 days, 400 days and 300 days as the upper value for malignancies there were statistically significant differences in these values between malignant and benign nodules(P < 0.01).Their sensitivities were 100.0%, 92.3%, 76.9% respectively and specificities were 87.5%, 91.7%, 100.0% respectively.Accuracies were 91.9%, 94.6% ,91.9% respectively and positive predictive values were 8,11,0.Conclusions Taking 400 days as the upper DTs'value for malignancies has important diagnostic value. Computer-aided diagnosis with three-dimensional volumetric measurement is sensitive to the volume changes of solid pulmonary nodules on follow-up CT, and is useful in the differential diagnosis of pulmonary nodules.

Objective To observe the clinical effect of dexmedetomidine combined with butorphanol in preventing tourniquet reaction.Methods Fifty patients(ASA Ⅰ-Ⅱ)with upper limb operation and satisfactory effect of brachial plexus block were randomly divided into the dexmedetomidine group(A)and dexmedetomidine combined with butorphanol group (B),25 cases in each group.The anesthesia drug preparation method in the group A:dexmedetomidine 200μg was added with normal saline 50 mL;in the group B:dexmedetomidine 200 μg,butorphanol 1 mg and normal saline 50 mL altogether.The group A used dexmedetomidine 1 μg/kg load for 15 min and maintained by 0.4 μg · kg-1 · h-1 until the end of operation;the group B was given 0.015 mg/kg butorphanol,then was given medication according the scheme of group A.The VAS score,BIS value,Remsay sedation score,HR,MAP and SPO2 were recorded at the time points:before medication (T0),immediately after the tourniquet inflation (T1),15 min (T2),30 min (T3),45 min (T4),60 min after tourniquet inflation (T5) and 10 min after deflation (T6).The subjective response classification count,respiratory depression,bradycardia and hypotension in the two groups were assessed.pH,PaO2,PaCO2,HCO3-and LAC at T6 were evaluated by theblood gas analysis.Results The VAS score,BIS value,Ramsay sedation score,HR and MAP at T4,T5 had statistical difference between the two groups (P＜0.05).In the group A,the good and poor subjective responses had 9 cases and 4 cases respectively,which in the group B had 13 cases and 1 case,the difference was statistically significant (P＜0.05);there was no respiratory depression,bradycardia and hypotension in the two groups;the blood gas analysis showed no statistical difference between the two groups.Conclusion Applying dexmedetomidine combined with butorphanol in upper and lower limb surgery under brachial plexus anesthesia can significantly prevent the tourniquet reaction,its effect is superior to single use of dexmedetomidine.

Objective To investigate the quantitative analysis of tissue diffusion of real-time elastography(RTE) in chronic renal allograft injury(CRAI) and the relationship between RTE and the level of serum creatinine(Cr).Methods Sixty-nine cases of allograft renal transplantation patients were detected by conventional ultrasound and RTE.According to the time after operation and Cr,they were divided into three groups:group A (in three months after operation and normal Cr,25 cases),group B (more than three months after operation and normal Cr,23 cases),and group C (more than three months after operation and high Cr,21 cases).The results were compared and analyzed.Results ①Contrast between group A and group B,there were differences on Cr and average ralative strain value(MEAN),area ratio of low-strain region (％ AREA),complexity (COMP),skewness (SKEW),(P ＜ 0.05).② In group B,there was correlation between Cr and ％AREA,MEAN,SKEW (r =0.682,P ＜0.05; r =0.628,P ＜0.05; r =-0.481,P ＜0.05).③To make ROC curve,MEAN has higher sensitivity (90.9％),COMP has higher specificity and accuracy (68.0％,81.8％).④ To apply the third result in group C,4 or 5 cases in 21 were abnormal.Conclusions There is a good correlation between the quantitative analysis of tissue diffusion and the level of serum creatinine.RTE can indirectly reflect CRAI,and it is a new method of ultrasonic to evaluate renal allograft function.

Objective To investigate the effect of venous indwelling needle on peripherally inserted central catheterization (PICC).Method Seventy-eight critical patients underwent PICC through external jugular vein using venous indwelling needle at the emergency treatment.Result The success rate for one-time puncturing was 97.4%,without any complications.Conclusion PICC through external jugular vein using venous indwelling needle is advantageous for its safety,fewer complications and longer indwelling duration.

BACKGROUND:Generaly, the stent surface modification, especialy seeding cels, may accelerate or cause stent endothelium, and cause restenosis for prevention of in-stent thrombosis.
OBJECTIVE: To develop the optimal conditions for vascular stents coated with bone marrow mesenchymal stem cels.
METHODS: Cerebrovascular stent was co-cultured with passage 3 bone marrow mesenchymal stem cels from rats at 1×106, 1×107, 1×108, and 1×109/L. Cels on the stents were examined with transmission electron
microscopy after 48 hours. A total of 160 male Sprague-Dawley rats were enroled, among which, 20 rats were as normal control group, and the remaining 140 were used for producing models of ischemic stroke that were
randomly sub-divided into seven groups at 8 weeks after modeling: stainless steel stent implanted group, polymer stent group, and different concentrations of cellstent composite groups. After 8 weeks of implantation, the
expression of vascular endothelial growth factor in these cels was examined by western blot assay. Rat platelet activation in different groups was determined by flow cytometry.
RESULTS AND CONCLUSION:Implanted stem cels were able to grow adherently on the stainless steel stent wal. When the planting cellconcentration was 1×107 cels/L, the cels and organeles were morphologicaly
normal and covered the stent surface wel. These coated cels also expressed vascular endothelial growth factor, suggesting that they functioned as endothelial cels, and they also significantly lowered platelet activation. When
co-cultured with 1×107/L bone marrow mesenchymal stem cels, the stent was covered wel with endothelial-like cels and had significant lower platelet activationin vivo.

Objective To investigate the value of acoustic radiation force impulse (ARFI)and color Doppler flow imaging (CDFI)in the diagnostic of acute rejection (AR)after liver transplantation.Methods B mode ultrasound,CDFI and ARFI exams were performed on fifty-eight patients who was diagnosed with AR through liver biopsy in our hospital.The liver allograft size,mean velocity of portal vein,hepatic vein spectrum waveform and shear-wave velocity were obtained and compared with the results of 30 healthy subjects as control group.Results Compare to control group,the AR group had a significant increase in liver allograft,decrease in mean velocity of portal vein,the elimination of triphasic wave of hepatic vein,and a significant increase in shear-wave velocity (P =0.000,0.000,0.007,0.000,respectively).The correlation coefficient between four criteria and grouping was 0.478,0.557,0.286,0.483,respectively.The area under ROC curves for diagnosing AR using the four criterias mentioned above was 0.914.Conclusions Combination of CDFI and ARFI in diagnosing of AR after liver transplantation has higher sensitivity and accuracy.

Objective To observe the efficacy, safety and feasibility of the four kinds of anticoagulation method in hemodialysis patients with high risk of hemorrhage. Methods 128 patients with high risk of hemorrhage who had undergone hemodialysis were randomly divided into four groups. In group A, 68patients were resorted with 30% regional sodium citrate anticoagulation(RCA). In group B, 60 patients were treated with local heparin anticoagulation. In group C, 64 patients were treated with low molecular weight heparin (LMWH). In group D, 66 patients received no heparinization hemodialysis. The changes of bleeding, clotting function, adverse effect and nursing strategies were studied. Results All patients of group A completed regular hemodialysis with satisfactory indices, 6 cases with bleeding and primary bleeding aggravated in group B, 8 cases with bleeding and primary bleeding aggravated in group C, 8 cases occurred grade three coagulation and finished dialysis in group D. 3 cases in group A and 2 cases in group B occurred adverse reaction, but no adverse reaction was seen in group C and D. Conclusions RCA is safe,effective and can be easily handled in regular hemodialysis. It is an ideal dialysate for hemodialysis in patients with high risk of hemorrhage.

Objective To investigate the role of phosphatidyl-inositol 3-kinase-Akt (PI3k-Akt) signal pathway in the attenuation of ischemia-reperfusion (I/R) injury by sevoflurane preconditioning in isolated rat hearts. Methods Ninety-six adult male SD rats weighing 220-280 g were randomly divided into 6 groups ( n = 16 each): sham operation group (group S); I/R group; sevoflurane preconditioning group (group SP); wortmannin group (group W); dimethyl sulfoxide (DMSO) group (group D) and sevoflurane preconditioning + wortmannin group (group SW) . Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95%O2-5%C02 at 37 ℃ . The hearts were continuously perfused for 180 min in group S. After 15 min of equilibration, the isolated hearts were subjected to 30 min of ischemia followed by 120 min of reperfusion in SP, W, D and SW groups. Croups SP, W, D and SW received 10 min of perfusion with K-H solution containing 2. 4% sevoflurane, 100 nmol/L wortmannin, 20 μmol/L DMSO, and 2.4% sevoflurane + 100 nmol/L wortmannin, respectively, followed by 5 min washout before I/R. Eight hearts in each group were selected and HR, left ventricular end-diabetic pressure (LVEDP), left ventricular developed pressure (LVDP), and ± dp/dtmax were recorded at the end of equilibration and at 15 min of reperfusion, Myocardial tissues were obtained at 15 min of reperfusion for determination of apoptosis (by TUNEL) and phosphorylated Akt (p-Akt) expression (by Western blot) . Another 8 hearts were selected at 120 min of reperfusion for determination of myocardial infarct size by TTC staining. Result Compared with group S, LVDP and ± dp/dt,^ were significantly decreased and LVEDP was significantly increased in groups I/R, SP, W, D and SW, and myocardial p-Akt expression was up-regulated in groups I/R, SP and D ( P ＜ 0.05). Compared with group I/R, LVDP and ± dp/dtmax were significantly increased, LVEDP and apoptosis index were significantly decreased, myocardial p-Akt expression was up-regulated, and myocardial infarct size was significantly reduced in group SP (P ＜0.05) . Conclusion Activation of PI3K-Akt signal pathway is involved in the attenuation of I/R injury by sevoflurane reconditioning in isolated rat hearts.