BACKGROUND: With the development of technology, poly-L-lactic acid/β-tricalcium phosphate composite materials show good characters in the tissue engineering, which can promote osteoblast proliferation, reduce rejection reactions, and improve bone healing in a dose-dependent manner. OBJECTIVE: To test the influence of poly-L-lactic acid with different molecule weights on the structure and function of poly-L-lactic acid/β-tricalcium phosphate composite scaffolds. METHODS: Poly-L-lactic acid with molecule weights of 200 000 and 380 000 were combined with β-tricalcium phosphate to produce composite scaffolds by using freeze-drying method. Porosity and pore size of the samples were measured. The fetal rabbit bone mesenchymal stem cells (BMSCs) were cultured and expanded in vitro. They were harvested and seeded into the prepared poly-L-lactic acid/β-tricalcium phosphate scaffolds. The 3-(4, 5-Dimethylthiazol-2yl)-2, 5 diphenyltetrazolium bromide (MTT) and alkaline phosphatase were examined for comparison between normal cultured BMSCs and those cultured on the different poly-L-lactic acid/β-tricalcium phosphate scaffolds. RESULTS AND CONCLUSION: Images of scanning electron microscope showed that the cells adhered to the scaffolds greatly. The value of MTT and alkaline phosphatase showed no significant difference (P > 0.05). The molecule weight of poly-L-lactic acid has no influence on the biological function of composite materials.

Objective: In recent years,botulinum toxin type A(BTX-A) has been investigated for the treatment of pain.This experiment was to investigate the antinociceptive effect of BTX-A intraperitoneal injection on visceral pain of rats and its effect on intestinal AChE and SP expression.Methods: 72 male adult Wistar rats were divided into four groups: BTX-A(2U,4U,and 6U) or vehicle(2ml) was injected intraperitoneally in B,C,D and A group.6 Rats of every group were challenged with acetic acid intraperitoneal injection after 1,4 and 8 weeks respectively.After abdominal writhing behaviors were monitored,the intestinal samples were immunohistochemical stained for AChE and SP examination.Results: At the end of one week,writhing test scores of rats in group C and D were decreased significantly compared with group A(P

BACKGROUND:Precision attachment has been widely used in complete denture because of its strong retention, good appearance, comfort and durability. Among them, magnetic attachment and bal-cap attachment are commonly applied for mandibular complete denture.
OBJECTIVE:To compare the clinical effects of magnetic attachment, bal-cap attachment and traditional clasp retainer used in the mandibular removable partial denture.
METHODS:A total of 45 patients with dentition defects were included in this study, they were treated with magnetic attachment, bal-cap attachment and traditional clasp retention of mandibular removable partial denture. Fifteen patients received one means. The satisfaction of patients and the periodontal health of abutments were observed after 3 years.
RESULTS AND CONCLUSION:Comparison of the patient satisfaction showed that, the aesthetics, retention conditions, masticatory function and comfort in magnetic attachment group were significantly better than traditional clasp retention group (P<0.05). The aesthetics and comfort in bal-cap attachment group were also better than traditional clasp retention group (P<0.05). There were significant differences on the retention conditions and comfort between magnetic attachment group and bal-cap attachment group (P<0.05). Gingival index was the highest in magnetic attachment group, then in bal-cap attachment group, and the lowest in traditional clasp retention group (P<0.05). The abutment tooth mobility degree was the lowest in magnetic attachment group, then in bal-cap attachment group, and the highest in traditional clasp retention group (P<0.05). The periodontal pocket depth in magnetic attachment group and bal-cap attachment group was lower than that in traditional clasp retention group (P<0.05). The alveolar bone height was the highest in magnetic attachment group, then in bal-cap attachment group, and the lowest in traditional clasp retention group (P<0.05). Experimental findings indicate that, precision attachment over-denture retention superior to traditional clasp removable partial denture in mandibular denture repairing. Magnetic attachment can provide better retention power and better protect the health of periodontal tissue compared with bal-cap attachment.

Objective To study a new endoscopic technique, double-balloon enteroscopy on its efficiency and indication of examining small intestinal diseases. Methods Thirteen patients suspected to suffer from small intestinal disease received double-balloon enteroscopy. By pumping the two balloons to grip the small intestinal walls, the enteroscope can be inserted further without forming redundant loops in the small intestine. Eight patients undergoing these procedures received a combination of sedative drugs and anisodam-ine intravenously. Results Nineteen procedures were performed in 13 patients, among them 8 patients were performed through anus and 11 patients through mouth. The enteroscope reached the 3th - 6th group small intestine through mouth or anus in average 80 minutes for each procedure. Eight positive lesions were detected or diagnosed by the enteroscopy and biopsy. The nausea, mild temporary abdominal pain and liquids effusing from the overtube occurred during examination through the mouth. There were no severe complications such as hemorrhage, perforation occurred. Conclusion The double-balloon enteroscopy is a new safe and controllable endoscopic procedure for those small intestinal disease patients without severe organ dysfunction and intestinal adhesion, and having the adventages of completing the procedure within 2-3 hours, allowing direct visualization of the entire small intestine, taking biopsy specimens to get pathological diagnosis, and is superior to barium enteroclysis.

BACKGROUND:At present, there are no studies of comparing the effect of silk fibroins from different sources in repair of osteochondral defects. OBJECTIVE:To compare the effect of mulberry silk- and tussah-derived silk fibroin scaffold materials in repair of osteochondral defect. METHODS:Totaly 20 New Zealand white rabbits were obtained to prepare osteochondral defect models on the unilateral knee joint and randomly divided into five groups: control group, experimental group 1, experimental group 2, experimental group 3 and experimental group 4. Rabbits in the control group were not implanted any materials. In the experimental group 1, 3 layers of mulberry silk protein scaffolds stuck together to fil in defects. In the experimental group 2, one mulberry silk protein scaffold coated with transforming growth factor-β3 was stuck with two mulberry silk protein scaffolds coated with bone morphogenetic protein-2 to fil in defects. In the experimental group 3, three layers of tussah protein scaffolds stuck together to fil in defects. In the experimental group 4, one tussah protein scaffold coated with transforming growth factor-β3 stuck together with two tussah protein scaffolds coated with bone morphogenetic protein-2 to fil in defects. At 8 weeks post surgery, articular cartilage repair area was observed histopathologicaly. Type I and II colagen expressions were determined. RESULTS AND CONCLUSION:The colagen fibers in experimental group 1 were widely distributed in the ful-thickness defect area. The colagen fibers in the experimental group 2 were paralely distributed on the surface of repair area, verticaly distributed from the middle and bottom to the top direction. Colagen was observed on the surface of repair area in the experimental group 3. The cartilage-like cels presented clumped distribution on the surface and at the bottom of scaffold. The type I colagen expression in the repair area was strongly positive in these four experimental groups. The type II colagen expression in the repair area of experimental 1 and experimental 2 groups was weak. The type II colagen expression in the repair area of experimental 3 and experimental 4 groups was strongly positive. These results demonstrate that these two kinds of silk fibroins can both repair osteochondral defects, in which mulberry silk proteins tend to form bone tissue, and tussah silk proteins tend to form cartilage tissue.

Objective To observe and compare the analgesic efficacy of femoral nerve block (FNB)and sufentanil for positioning patients with fractured hip.Methods Sixty patients scheduled for hip fracture surgery were randomized into three groups.Fifteen minutes before positioning for subarachnoid block,the FNB group received nerve ultrasound guided FNB using 20 ml ropivacaine 0.5% .Five minutes before positioning,the S group received a dose of IV sufentanil 0.15μg/kg,the C group didn't accept any intervention.The visual analog scale(VAS)following positioning (T2 ),OAA /S scale before positioning (T1 ),MAP,HR,SpO2 entering operating room (T0 )and T1 ,T2 ,adverse reactions were recorded.The plasma concentration of noradrenaline(NA)and cortisol(Cor)by T0 and T2 were measured.Results MAP,HR,the level of NA,Cor by T2 in group C increased significantly by comparing with T0 (P <0.05),while there were no obvious change in group F,and the same to group S except NA.The obvious change of SpO2 couldn't be found at each time point in every group(P >0.05).There were no significant differences in MAP,HR,the level of NA,Cor in all instances among the three groups(P >0.05).The OAA /S of S group was higher than the other groups(P <0.05).Compared with group C,group F and S showed markedly lower VAS at T2 (P <0.05),there were no significant differences between the two group.Side effects of group S included respiratory depression in 3 patients,nausea vomiting in 1 and dizzy in 1,no adverse reaction were found in other groups.Conclusions Both FNB and intravenous sufentanil can reduce the pain of positioning patients with fractured hip,showing almost the same analgesic efficacy,FNB can more inhibit stress reaction caused by pain.

One kind of glycosaminoglycans (GAG) was extracted and purified from the ink of Sepiella maindroni de Rochebrune by using the procedures of trypsin and pronase digestion, ethanol precipitation and DEAE-cellulose inon-exchange chromatography. It was proved to be homogeneous by polyacrylamide gel and cellulose acetate membrane electrophoresis. No protein absorption was shown in UV spectrum, but typical absorption of GAG was shown in the IR spectrum. It was identified by paper and thin layer chromatography of the acid hydrolyzate that the GAG was composed of galactosamine, glucuronic acid and fucose. The percentage content of galactosamine, glucuronic acid, fucose, sulfate and protein in the GAG was 25. 6%, 29.2%, 23.3%, 8.2% and 3. 5%, respectively.

Objective To study the effects of internal and external biliary drainage on inducible nitric oxide synthase (iNOS) mRNA expression of Kupffer cells and serum tumor necrosis factor-alpha (TNF-α) in rats with obstructive jaundice. Methods Forty-eight male Sprague-Dawley rats were randomly assigned to obstructive jaundice (OJ), sham operation (SH), internal biliary drainage (ID) and external biliary drainage (ED) groups with 12 each. Kupffer cells were isolated by in situ hepatic perfusion and digestion with collagenase type Ⅳ, and purified by cell culture attachment. The expression of iNOS mRNA of Kupffer cells was detected by reverse transcription polymerase chain reaction (RT-PCR) and the serum TNF-α concentration was measured using ELISA method. Results The serum TNF-α level was increased in OJ group[ (110.84±26.3) pg/ml ]compared with SH group [-(88.4±17.9) pg/ml, (P=0.045)]. The TNF-α level in ID group[ (89.8±28. 3) pg/ml ]was significantly lower than that in ED group[ (118.64±22.7) pg/ml, (P=0. 011) ]and OJ group (P=0. 059). Expression of iNOS mRNA of Kupffer cells was significantly higher in OJ group (0. 824± 0. 24) compared with SH group (0. 384±0.35,P=0. 005). After relieving the OJ, the iNOS mRNA expression in ED group (0. 974± 0.48) was not suppressed (P=0. 321). On the contrary, the iNOS mRNA expression in ID group was suppressed and significantly lower than that in ED group (0. 59±0. 35) (P=0. 016). Conclusions Internal biliary drainage is superior to external drainage in terms of reversing the elevated serum TNF-α and in suppressing the iNOS mRNA expression of Kupffer cells in rats with obstructive jaundice.

Objective Apaf-1 is a key factor involved in activating the Caspase system in apoptosis. The aim of this study was to evaluate the significance of Apaf-1 on the apoptosis process induced by chemotherapeutic agent. Methods We established Apaf-1 hyper- and hypo- expression system by transferred sense and anti-sense Apaf-1 cDNA into cultured AGS cell line. And meanwhile human cyt-c, Apaf-1, caspase-3, bax, and bcl-2 gene expressions were measured by RT-PCR method. Results Cyt-c, caspase-3, and bax gene expressions increased significantly after sense Apaf-1 transfection. On the contrary, anti-sense Apaf-1 transfer has minus effects on cyt-c, caspase-3, and bax gene expressions. No significant changes have been found on bcl-2 gene expression after transfection process.Conclusions Cyt-c pathway may play an important role in the apoptosis induced by chemotherapeutic drugs. The early expression of cyt-c and Apaf-1 may be the key procedure of cyt-c release from mitochondria and of caspases activation.

The lack of medical ethics education among young doctors substantially hinders the construction of a harmonious physician-patient relationship under the current condition. This paper addresses the disharmonies and ethical conflicts in current physician-patient relationship, and sheds light on major factors related to the causes of the lack of medical ethics education among young doctors. Furthermore, special considerations and coping strategies to eliminate this dilemma are also provided.