BACKGROUND: Carbon nanotubes (CNTs) is about 1 mm in diameter and about 1-10 μm in length cylinder-like material, and it only contains the spiral of carbon atoms arranged on the surface. Because of its unique tubular structure, lower density than that of graphite and with a high enough intensity, CNTs are expected to substitute bone.OBJECTIVE: To primarily study the influence of the content of polycarbosilane (PCS) and the sintering pressure on CNTs, look for the most optimum condition for the preparation of chunk CNTs, analyze the physical properties and biocompatibility of the material, and provide a choice for candidate implant denture material.DESIGN: The content of cement and the sintering pressure are adjusted in the experiment to make sure the most optimum condition for the preparation, and the capabilities of the material are observed and analyzed to make sure if that the material is suitable for implant denture.SETTING: Department of Stomatology, Xiangya Hospital, Central South University; Prosthodontics Staff Room, Oral Medical College of Central South University. MATERIALS: 80% pure molecules of CNT (Nano Lab Company USA), 20-40 nm in diameter, 5-20 mm in length, was provided by Nacheng Technology Development Corporation of Beijing. PCS was compounded by 502 Development Room of Defense Technology University, and the molecular weight is 1 300; Ten male white Wistar rats with 8 weeks old were provided by Animal Experiment Center of Guangxi Medical University. The treatments with the animals accorded to animal ethical standard in the experiment.METHODS: The experiment was carried out in the Experimental Center of Material College, Central South University from January to August 2005. By using the spark plasma sintering (SPS), at the sintering temperature of 1 200 ℃, the pressure from 20 MPa to 60 MPa, PCS was used as the cement to produce the new chunk multi-wall CNTs.MAIN OUTCOME MEASURES: By using Archimedes method and adsorption of gases method, Japanese MitutoyoHM-101 little burden Vickers hardness meter was used to test the apparent bulk density, specific surface area, Vickers hardness at the different contents of PCS and sintering pressures. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to observe the microstructure of the material.RESULTS: ① Microstructure: SEM and TEM indicated that the nanotube structure of the material was retained after sintered. ② Conforming phase of material: X-ray diffractometer indicated that carbon nanotubes were felt by PCS pyrolysis product of SiC; along with the PCS content and sintering pressure increased, the specific surface area was reduced, and Vickers hardness and density increased. Specific surface area decreased. ③ Histological compatibility: The inflammatory reactions of the CNTs/PCS were little more serious along with the increase of the content of PCS. The physical property of carbon nanotubes was prepared in this way, it was closed to bone tissues, it had the better biocompatibility, and it was the suitable candidate implant denture material.CONCLUSION: Appropriate to PCS for the bonding agent, through SPS, at 1 200 ℃, 20-60 MPa sintering pressure, CNTs/PCS which the material property is closed to bone tissues can be prepared, and CNTs/PCS subcutaneous implantation in rats does not show significant rejection; therefore, it is suitable candidate for dental implants material.

BACKGROUND: Titanium cage of cervical vertebral fusion is often used during a surgical operation for cervical syndrome; however, it has a bad impact on the operative effect because of submerging.OBJECTIVE: To observe the biocompatibility and stability of cervical fusion cage of high molecular polyethylene in animals.DESIGN: A randomized grouping and observational control experiment.SETTING: The Animal Experimental Center of Zhengzhou University.MATERIALS: Twenty female goats without pregnancy at 1.1-1.6 years of age.METHODS: The experiment was conducted at the Animal Experimental Center of Zhengzhou University between June and November 2001. Twenty goats were equally randomized into experimental group and control group.Self-made cervical fusion cage filled with autogenous spongy bone was implanted into the goats in the experimental group, only autogenous iliac bone was implanted in the control group. X-ray for observing the changes in the height of intervertebral space was performed in two groups 6 weeks later. All the animals were killed under anesthesia to extract cervical vertebra samples, which were placed on YJ-14 Biomechanical Tester to measure anti-compression ability and height of intervertebral space and to observe pathological changes.space: Compression loading in the experimental group was significantly higher than that in the control group [(358.64±15.63),(268.82±11.36)N,P ＜ 0.05]; however, there was no difference in the height of interverteA great amount of osteoblasts were found in the tissues around the cage in the experimental group, but there was no difference between the two groups.CONCLUSION: The self-designed cervical vertebral fusion cage possesses high upholding strength, good biocompatibility and stability and can play a role in stabilizing the height of intervertebral space.

Objective To investigate the changes of the serum high sensitive C-reactive protein (hs-CRP)level in patients with acute cerebral infarction (ACI) and study the relationship between hs-CRP level and ischemic stroke subtypes according to the trail of org10172 in acute stroke treatment (TOAST) criteria.Methods The serum hs-CRP was measured in 152 ACI patients by immunonephelometrical method. All ACI patients were classified into 5 major ischemic stroke subtypes based on TOAST criteria. And then the relationship between hs-CRP level and their TOAST subtypes were analysed.Results The percentage of each ischemic stroke TOAST subtypes of 152 patients was as following: stroke of undetermined etiology 41.45%, small-vessel occlusion 34.87%, cardioembolism 5.26%, large-artery atherosclerosis 15.79%, and stroke of other determined etiology 2.6%. Among 5 ischemic stroke subtypes, cardioembolism patients were related to the highest positive rate of hs-CRP(87.50%) and the highest hs-CRP level [(11.60?7.85)mg/L]. The hs-CRP level in large-artery atherosclerosis or stroke of other determined etiology were (10.77?4.27) mg/L or (6.45?3.25) mg/L respectively, Stroke of undetermined etiology and small-vessel occlusion subtypes were associated with the lowest positive rate of hs-CRP(38.10%, 37.74%) and the lowest hs-CRP level [(4.09?5.65)mg/L,(3.99?0.56)mg/L]. Apparently, other factors, such as age, systolic blood pressure, cholesterol, triglyeride, fasting blood sugar and fibrinogen, could also affect the hs-CRP level in serum(r=0.1640、0.2489、0.2066、0.1866、0.3029、0.2224,all P

95%) was performed in 62 cases, a subtotal resection (76%~95%) was performed in 6 cases, and a partial resection (≤75%), 2 cases. No peri-operative deaths occurred. Transient diabetes insipidus was noted in 24 cases and was cured within 3 weeks after operation. Nasal cerebrospinal fluid leakage was observed in 8 cases, 5 of which spontaneously recovered after 2 weeks of bed rest, and 3 of which were cured by lumbar cistern drainage. Follow-up observations for 3 months ~ 2 years (mean, 7 months) in 48 cases found 2 cases of recurrence. Conclusions Transnasal transseptal transsphenoidal approach adenomectomy is an effective and minimally invasive procedure, with simplicity to performance, short operative time and fewer complications.

0.05). But there were statistic difference in the those indexes and pathological changes of bile duct and liver between A and ligation groups on the 30th and 90th day after operation (P

Objective To study the correlation of NF-?B expression with the grade, the stage, the recurrence, the metastasis and PKC expression of bladder transitional cell carcinoma. Methods The expression of NF-?B and PKC was examined with SP immunohistochemical method in 54 cases of paraffin-embedded bladder transitional cell carcinomas tissues and 13 cases of normal bladder tissues. Results The positive expression rate of NF-?B P65 and PKC in bladder transitional cell carcinomas was 88 9% and 81 5% respectively. The expression rate of NF-?B decreased along with pathological grade and clinical stage increased, while its expression increased along with the rate of recurrence and metastasis elevated. There was a positive relationship between NF-?B and PKC expressions. Conclussion NF-?B may play a role at early stage of bladder transitional cell carcinoma. It probably serves as an index to evaluate the malignant extent and progression of bladder transitional cell carcinoma. PKC probably takes part in the activation process of NF-?B.

Objective To investigate the association between CYP2C19 polymorphisms and efficacy of clopidogrel in Chinese Han patients with coronary atherosclerotic heart disease.Methods A total of 176 Chinese Han patients who underwent percutaneous coronary intervention and were treated with dual antiplatelet therapy with aspirin and clopidogrel were enrolled.Polymorphisms of CYP2C19 * 2,* 3 were measured by PCR-restriction fragment length polymorphism (PCR RFLP).The correlation between the genetic variants and cardiovascular events was analyzed.Results In the 176 patients,the allele frequencies of CYP2C19 * 2 and * 3 were 34.38％ and 5.97％ respectively,the percent of patients with poor metabolizer genotypes (* 2/* 2,* 2/* 3,* 3/* 3) was 14.20％.Among the 176 patients,11 patients reoccured acute coronary syndrome,1 patient suffered from stroke,and 4 patients had stent thrombosis.The incidence of cardiovascular events was 9.09 ％.Thecumulative incidence of cardiovascular events had no significant differences between poor metabolizer genotype carriers and extensive and intermediate metabolizer genotype carriers (16.00％ vs.7.95％,x2 =1.683,P=0.195).Conclusions The frequencies of CYP2C19 poor metabolizer genotypes are higher in Chinese Han population than in Caucasians,but the incidence of cardiovascular events in Chinese Han population is not increased.

Purpose:To study the clinic characteristic, diagnosis and therapy of hereditary nonpolypoid colorectal cancer.Methods:We analysed the diagnosis, therapy and follow up of hereditary nonpolypoid colorectal cancer in 32 cases from 11 families by studying the tumour site, pathologic results. Results:There were 43 cancer patients having 61 tumours in 11 families, and 32 cases were intestinal cancer with 39 tumours. In these 32 cases, there were 12 hereditary nonpolypoid colorectal cancer (37.5), and 5 cases were intestinal cancer (15.6). We examined the patients and their direct relatives and found 28 people had various cancer, of which 20 cases without any complaint. Conclusions:Hereditary nonpolypoid colorectal cancer is a dominant hereditary disease, with the characteristic of early flare up,prone to upper colon. They are always non contemporary polygeneous cancer or contemporary polygeneous cancer, and prone to take place outside of colon. So it is important not only for patients to be treated and followed up but also for their relatives to be instructed and followed up. We must study the disease history in details. [

Objective To investigate the expressions of CD133 and CD44 and their prognostic significance in gastrointestinal stromal tumors (GIST).Methods Streptavidin perosidase (SP) method of immunohistochemistry was used to detect expressions of CD133 and CD44 proteins in 42 cases of GIST, and the relationship between their expressions and tumor size, mitotic count were analyzed by univariate and multivariate factor analyses.Results The expressions of CD133 and CD44 proteins in GIST were 21.4％ (9/42) and 78.6％ (33/42), respectively.The expressions of CD133 and CD44 proteins were significantly correlated with tumor size and mitotic count (P ＜ 0.05).Univariate factor analysis showed that the overall survival of GIST patients with positive CD133 protein (23.2 months) was shorter than that of patients with negative CD133 protein(63.1 months) (P ＜ 0.05).The overall survival of GIST patients with negative CD44 protein (23.2 months) was shorter than that of patients with positive CD44 protein (63.3 months) (P ＜ 0.05).Multivariate factor analysis showed that tumor size, mitotic count and CD44 protein were independent prognostic indicators for survival time after operation.Conclusions The positive expressions of CD133 and CD44 proteins might be the prognostic factors of GIST patients.

Objective To investigate the effects of shRNA targeting a disintegrin and metalloproteinases 17(ADAM17)on the proliferation of human breast cancer MCF-7 cells in hypoxia environment.Methods The four specific ADAM17-shRNA se-quences aiming at ADAM17 were designed,transfected into MCF-7 cells by electroporation,and cultured in hypoxia environment. The experiment was divided into the control group (blank phosphate buffer solution,PBS),nonsense sequence group (transfected with ADAM17-shNC)and shRNA transfection group (transfected with ADAM17-shRNA,the highest silencing efficiency of shR-NA was selected for following experiments).Real-time PCR was used to detect the expression of ADAM17 mRNA.The prolifera-tion ability and cell cycle change of MCF-7 cells were detected by iCELLigence and flow cytometry (FCM),respectively.Results Compared with control group and nonsense sequence group,the four ADAM17-shRNA transfection groups all had the silence effect on ADAM17 gene expression (P <0.05 ),the difference was statistically significant(P <0.05 ),particularly shRNA1219 had the highest inhibitory rate (F =5.11,P <0.01 ).The cellular proliferation ability and cell growth speed in the shRNA transfection group were significantly decreased compared with the control group and nonsense sequence group (P <0.05).Most cells of shRNA transfection group remained in the G0/G1 phase (73.35 ± 2.45 ),which in the control group and nonsense sequence group was (62.56±2.35)and (62.68 ±1.20)respectively,the difference was statistically significant(P <0.05).The cell cycle progression was significantly delayed.Conclusion ADAM17-shRNA inhibits the proliferation of MCF-7 cells under hypoxic environment.