Patients with asymptomatic carotid stenosis (ACS) are the potentially high-risk population of stroke.Screening for high-risk patients with ACS and giving them appropriate interventions may have great significance for the prevention of the occurrence of stroke.This article reviews the advances in research of ACS screening in recent years.

AIM:To observe the expression and tissue localization of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta 1 ( TGF-β1 ) in the rat acute cerebral ischemia model.METHODS:Male Wistar rats were used to establish acute cerebral ischemia model by a suturing method.The rats were divided into normal control group, sham group and ischemia 6 h, 12 h, 1 d, 2 d, 6 d and 14 d groups.The rat cerebral cortex and hippocampus of the brain were collected at different time points.The mRNA and protein levels of MMP-9 and TGF-β1 in the brain tissues were detec-ted by real-time PCR and in situ histochemistry staining, respectively.The levels of MMP-9 and TGF-β1 in the plasma were also measured by ELISA.RESULTS:The results of real-time PCR showed that the mRNA levels of MMP-9 began to in-crease 6 h after acute ischemia and reached to a peak 2 d after acute ischemia.Similarly, the mRNA level of TGF-β1 began to rise 12 h after acute ischemia and reached to the highest level 6 d after acute ischemia.Compared with the sham rats, the mRNA levels of MMP-9 and TGF-β1 in the rat brains that collected at ischemic time of 12 h, 1 d, 2 d, 6 d and 14 d were significantly increased.Moreover, results of in situ histochemical staining showed that the expression of MMP-9 was detected at cerebral cortex and hippocampus 1 d after acute cerebral ischemia.Further studies showed that MMP-9 dyeing of the rat cerebral cortex was most obvious 2 d after the acute cerebral ischemia.Similarly, the rat cortex and hippocampus began to express TGF-β1 2 d after acute ischemia and TGF-β1 staining at rat cerebral cortex was most obvious 6 d after the acute cerebral ischemia.In addition, ELISA showed that the increase in MMP-9 and TGF-β1 was detected in the plasma 12 h after ischemia.Compared with the sham rats, the level of these 2 factors significantly upregulated since 1 d after ischemia. CONCLUSION:The brain tissue itself contributes to the upregulation of MMP-9 and TGF-β1 post acute cerebral ischemia, which shed light on the related research in the field.

BACKGROUND:Surface modification of titanium surface to improve its biological activity is the research hotspot. Strontium-doped coating is considered to be an effective approach to promote the implant osseointegration. OBJECTIVE:To introduce the research progress of strontium-modified biomedical titanium al oys.METHODS:Articles related to the medical titanium al oys modified with strontium published from January 2000 to April 2016 were retrieved from CNKI and PubMed databases. The keywords were“titanium (Ti), strontium (Sr), bone, osteogenic”in Chinese and English, respectively. RESULTS AND CONCLUSION:Titanium al oys have been widely used in bone implantation because of their good biocompatibility and similar elasticity modulus with human bones. However, pure titanium al oys have poor bioactivity which leads to weak bone-implant contact. Surface modification is a good approach to enhance implant osseointegration. Sr-doped surface treatment can promote new bone formation and osseointegration. Most of the studies about Sr-doped modification are ongoing at the extracorporeal and animal experiment stage;therefore, further investigation is required to seek rapid, stable, available, safe and effective methods.

BACKGROUND: Porosity has been proven to improve the stability of orthopedic implants, and the architecture of pores is considered as a significant factor to improve the osseointegration of implants. OBJECTIVE: To introduce the research advance in porous architecture. METHODS: WOS database was searched for the articles addressing the porous structure of the implants published from January 2000 to April 2016 using the keywords of scaffold, pore size, porosity, osteogenesis. The literatures were screened according to the inclusion and exclusion criteria.RESULTS AND CONCLUSION: (1) The stability of traditional implants cannot meet the requirements in some specific circumstances, while the implants with porosity can improve the stability due to its osteogenesis ability. (2) Porous structure is a hotspot, and the osseointegration of porous implants in vivo is explored through series of in vitro and in vivo experiments. (3) It has been shown that higher porosity, proper pore size, microporous morphology and microstructure of the pore wall may contribute to the growth and differentiation of bone tissue under enough mechanical support. (4) However, most studies on the porous implants are still on the in vivo and animal experimental stage, and its promoting effects on the osteogenesis and bone in-growth are needed to be investigated in depth.

BACKGROUND:Titanium alloy, a commonly used bone biomaterial, holds good biocompatibility and proper mechanical properties, but without osteointegration ability. Surface bioactive coating of titanium alloy can overcome such problems. OBJECTIVE:To review the application progress of surface bioactive coating on titanium alloys, and to explore the mechanism underlying its osteogenic induction. METHODS:PubMed and CNKI databases were searched for literatures concerning surface bioactive coating on titanium alloys published from January 2000 to March 2016, using the keywords oftitanium, titanium alloys, coating, surface modification, bonein English and Chinese, respectively. Through preliminary analysis, 42 eligible articles were selected. RESULTS AND CONCLUSION:The surface modification method has undergone the transition from surface roughening, oxidation, acidification treatment to the most widely used biomimetic coating technology. The surface biomimetic coatings of titanium alloys mainly include hydroxyapatite, bioactive glass, zeolite, which have been developed from a single coating to the composite coatings and gradient coatings. What's more, the bioactive factor or/and metal ions in the coating can improve the osteointegration of surface coating. Surface modification for titanium alloys is a complex process, during which, both the osteogenesis ability and the bonding strength between the coating and its substrate cannot be ignored. Improving the fabrication method of existing coatings and exploring new materials of biomimetic coatings are critical to achieve a high-quality surface coating modification.

Objective To observe the efficacy of endoscopic resection with thyroid benign tumor. Methods 60 cases of thyroid benign tumor were randomly divided into the endoscopic group and the traditional group, 30 cases in each group. The operation time, blood loss ,drainage volume, postoperative hospital stay, postoperative complications and hospitalization expenses in two groups were compared. Results There was no significant difference ( P >0. 05) between the two groups of postoperative hospital stay; endoscopic group blood loss (25.3 ± 15.6) ml significantly less than the traditional group (57. 2 ± 33. 8) ml, the difference was statistically significant ( P < 0. 05); endoscopic postoperative drainage volume ( 85.6 ± 53.2) ml significantly more than the traditional group ( 23. 5 ±37.2) ml (P < 0. 05); endoscopic operative time of ( 105.3 ± 23. 5) min, while the traditional group ( 80. 4 ±25. 3 ) min, the difference was significant ( P < 0. 05 ); hospitalization costs were significantly higher than conventional endoscopy group ( P < 0. 05). Both groups were not have obvious complications postoperation. Conclusion Compared with traditional open surgery, endoscopic surgery for benign thyroid tumors has advantages of superior cosmetic results and less bleeding,it is a good choice for the treatment of the disease.

Objective: To study the acute toxicity of Xiaobai capsules in mice after intragastric administration .Methods: The mice were randomly divided into two groups , the treatment group and the control group .The treatment group was given Xiaobai cap-sules by gavage, 3 times daily.The acute toxicity was recorded, and the median lethal dose (LD50) and the maximum dose were deter-mined.Results:The maximum daily dose of Xiaobai capsules was 141.6 g· kg-1(equivalent to 211.3 times of the clinical dose).At the dose, the mice showed no toxicity without death in 14 days or changes in organs after the dissection .Conclusion:Xiaobai capsules have very low acute toxicity in mice after intragastric administration with high security .

Objective To design and testify a novel strategy for acquiring mimetic epitope mapping by screening for a phage random peptide library using polyclonal anti keratin autoantibodies (AK auto Ab). Methods AK auto Ab were isolated and purified from pooled human sera by keratin affinity column in which keratin had been linked with CNBr Sepharose 4B,then biotinylated by the biotin ester. A 15 mer phage random peptide library was biopanned for 3 cycles and positive clones were identified by ELISA,competition assay and DNA sequencing. ResultsBy sequence comparison 23 positive clones were selected randomly and three epitopes were confirmed. Among the three epitopes SLSPMPTTNRR was the dominant epitope. The phages carrying positive clones reacted with AK auto Ab specifically and keratin could prevent interaction between AK auto Ab and positive phages. Conclusion The designed strategy is successfully applied in acquiring epitopes of polyclonal autoantibodies to keratin, which could provide a new approach for the discovery of epitope mapping which binds to natural autoantibodies.

Objective We set up an uncertainty assessment method for determination of iodides in water by As3+-Ce4+ catalytic spectrophotometry, in order to assess the accuracy of the method and the major influencing factors, and to build up an equation to assess the uncertainty in the mobility of working curve and an uncertainty assessment method for pipettors.Methods According to Methods for Water Iodine Detection Suitable for Iodine Deficiency and Iodine Excess Areas, the uncertainty items of the two standard materials (GBW09114c and GBW09113c) in different concentrations, such as repeatability of measurement, the mobility of working curve, the uncertainty of standard solution and sample solution, etc, were analyzed.Results The contents of iodide in GBW09114c and GBW09113c were (61.3 ± 1.4) and (8.1 ± 0.3)μg/L;relative expanded uncertainty RU1 and RU2 were 2.25％ and 3.46％, both of them were in the range of acceptable deviation in the standard material certification (10.0％ and 14.8％).Major influencing factors were repeatability of measurement, the uncertainty of standard solution (including the uncertainty of potassium iodide reference reagent and glass equipment), and the uncertainty of sample solution (including the uncertainty of pipettors).A more adaptable equation for the mobility of working curve had been proposed;the factors involved in environment temperature and operation repeatability were used as the items of the pipettors' uncertainty.Conclusion This method can be used to assess the uncertainty in determination of water iodides by As3+-Ce4+ catalytic spectrophotometry.

Objective Analyze the clinical feature of patients failed for diagnosis through endobronchial ultrasound transbronchial needle aspiration(EBUS-TBNA).Optimize the indication and increase diagnosis rate of EBUS-TBNA.Methods A total of 669 patients failed for diagnosis of EBUS-TBNA were included.Fifty-three of them(7.92％) were not exactly diagnosed.Perioperation clinical data and clinical feature were collected and evaluated based on specific disease,lesion location,size and operator' s experience.Results The undiagnosis rate was higher in lymphoma (77.78％),tuberculosis (23.08％) and sarcoidosis(9.09％) when analyzed from specific diseases.If the lesion location was taken into consideration,15.38％ upper paratracheal lymph nodes(R2) could not be diagnosed exactly by EBUS-TBNA,and the bilateral hilar lymph nodes(15.00％ for right,11.54 for left) were followed.Size of the lesion was not associated with the diagnosis rate.The operator's experience could also affect the results.The undiagnosis rate was highest in the first 10 cases among all operators.After at least 10 EBUS-TBNA processes,the undiagonsis rate stayed near 7.50％,which was close to the average.Conclusion It is necessary to select suitable indications for EBUS-TBNA based on the disease,lesion location and operatior experience,and cooperate with mediastinoscopy to rise diagnosis rate.