Difficult-to-treat asthma is a complex disease with poor response to high-dose inhaled corticosteroids plus a second controller or need high levels of treatment to maintain control.Difficult-to-treat asthma represents a significant clinical challenge and a heavy medical burden due to its heterogeneity.Identification of the phenotypes and endotypes in difficult-to-treat asthma is very helpful for individualized therapy.This review summarizes the latest studies on the classification of difficult-to-treat asthma in order to provide evidence for the diagnosis and treatment of difficult-to-treat asthma in children.

Objective To study the method based on gradient vector flow (GVF) and particle swarm optimization (PSO) for realizing multimodal medical image registration and improving its accuracy. Methods In view of three major components of image registration, i.e. the feature space, the similarity metric and the search strategy, a novel method was proposed with three improvements. Firstly, the GVF field was employed as the feature space. Then three similarity metrics were proposed based on GVF field. Finally, an improved PSO combined with crossover mechanism of genetic algorithm was utilized to search for the optimal transformation of two images. Results With 54 times of experiments on both simulated and real medical images, it was demonstrated that this method accurately registered the multimodal medical images to be superior to the method based on PSO of pixels, and the Walsh transform method. Conclusion The method based on GVF and PSO is effective for multimodal medical image registration.

Objective To evaluate the diagnostic value of DCE-MRI and breast MR reporting and data system(BI-RADS-MR)in differentiation of breast lesions. Methods Seventy-five patients with 75 pathological-confirmed breast lesions underwent DCE-MRI before treatment and DCE-MRI quantitative analysis. Two senior doc-tors assessed the imaging features blindly by BI-RADS-MR. The pathology results were set as a gold standard. The receiver operating characteristic curve(ROC)interpretation of two physician′s curve analysis was used to evaluate the sensitivity,specificity of BI-RADS classification. Results According to the BI-RADS MR score,38 breast cancer patients were rated as 1 case in grade Ⅰ,0 case in grade Ⅱ,4 cases in gradeⅢ,13 cases in gradeⅣ,20 cases in grade V;37 breast benign tumors were rated as 17 cases in grade Ⅰ,5 cases in grade Ⅱ,12 cases in gradeⅢ,3 cases in gradeⅣandⅤ0 cases. The statistical difference of Tpeak,S max,K1 between benign and malig-nant breast tumors were significant(P<0.05). On ROC,the area under the curve was 0.940,95%confidence in-terval was from 0.887 to 0.994. The sensitivity of BI-RADS in the diagnosis of breast cancer was 94.59%and speci-ficity was 92.11%. Conclusion DCE-MRI combined with BI-RADS-MR classification in diagnosis of benign and malignant breast tumors has an important value and can improve diagnosis and differential diagnosis level.

Objective To compare the clinical effects of proximal femoral nail antirotation (PFNA) and dynamic hip screw (DHS) in the treatment of intertrochanteric fractures in elderly patients.And provide a reasonable basis for clinical treatment of elderly patients with intertrochanteric fractures.Methods The clinical and follow-up records of 58 elderly patients with intertrochanteric fractures treated by PFNA and DHS were retrospectively reviewed.For times of operation,blood loss in operation,length of incision,incidents of complication and Harris's hip functional standard score were compared and analyzed.Results PFNA group operation time[(59.61 ± 8.27)min],amount of bleeding[(234.51 ± 38.80)ml] were both better than the DHS group of[(83.54 ± 11.12)min and (446.57 ±54.01) ml] respectively.There were significant differences (t =9.80,18.10,all P ＜ 0.05).The satisfactory rate was 92.8％ in PFNA group,higher than the DHS group's 83.3 ％ (x2 =6.18,P ＜ 0.05).There was significant difference between two groups in the incident of complication,DHS group was higher.Conclusion PFNA internal fixation with a minimally invasive,fixed solid and recovery fast,is the better internal fixation in the treatment of elderly intertrochanteric fracture patients.

BACKGROUND:Polyvinyl alcohol is a biocompatible and biodegradable polymer. It is widely used in clinical areas because of its water-soluble, film forming, emulsification, adhesiveness, tasteless, and nontoxic.
OBJECTIVE:To review the applications of polyvinyl alcohol and its composite materials in bone, cartilage, skin, vessels and other tissue engineering scaffolds.
METHODS:A computer-based online search of CNKI database from January 2000 to December 2011, PubMed database and Elsevier (ScienceDirect) database from January 1980 to December 2012, was performed by the first author with key words of“poly(vinyl alcohol), composite material, tissue engineering scaffold”both in Chinese and English. Literatures concerning polyvinyl alcohol and its composite materials in bone, cartilage, skin, vessels and other tissue engineering scaffolds were included, and repetitive research was excluded.
RESULTS AND CONCLUSION:Although there are not enough strength, complications and other shortcomings in vivo, due to its good biocompatibility and biodegradable properties, polyvinyl alcohol and its composite
materials have made great progress in tissue engineering applications from the laboratory to the pre-clinical
research. But its long-term effects need further research. It wil be a main research aim of scaffold materials in the future to improve the interaction of cel s with the scaffold materials by surface modification, to prepare biomimetic materials by cel microenvironment simulation, to improve the hydrophilicity, the adhesion of cel s, and cel
differentiation and proliferation, to bionic the structure and function of the natural extracel ular matrix by building three-dimensional porous structure and control ing the release of cel growth factors, to meet the need of tissue regeneration by congruity or harmony of degradation and mechanical strength.

Objective To research clinical significance of electrocardiogram(ECG) measuring in diagnosis of hyperkalemia. Methods ECG changes and serum potassium concentration from 72 cases have been analyzed and contrasted. Results Forty-one cases with hyperkalemia are detected by ECG changes. Coincidence rate is up to 56.9% with serum potassium test. When the serum potassium concentration exceeds 5.5mmol/L, the accuracy of ECG in diagnosis of hyperkalemia was 22.2%. The main features arc peaked T wave with tabernacle shape ;when the serum potassium concentration exceeds 6.7mmol/L, the accuracy of ECG in diagnosis of hyperkalemia was 74.3%. The main features are ST debased,P wave with low amplitude and time limit increased. Some patients appeared sinus node-ventride conduction. One or two appeared malignant ventricular arrbythmia; when the serum potassium concentration exceeds 10.0mmol/L,the accuracy of ECG was 100% ,most patients appeared malignant ventricular. Conclusion The electrocardiogram measurement has the better consistency with serum potassium test, and abnormal electrocardio-gram will be eccurred,when mixed other electrolyte unbalance. Pseudo-hyperkalemia can be distinguished accurately and conveniently by using this method.

Objective To observe the relationship between liver steatosis in rats with long-term high-caloric and high-fat diet and the expression of angiotensinogen(AGT)、uncoupling protein 2(UCP-2)and transforming growth factorβ1(TGFβ1).Then angiotensin-converting enzyme inhibitor(ACEI)and angiotensin Ⅱ receptor blocker(ARB)drugs were given to investigate whether rennin-angiotensin system (RAS)blockade can mitigate the liver steatosis and to probe its mechanisms.Methotis Forty male Wistar rats were divided into normal control group(NC group,n=10),high-calorie and high-fat fed group(HF group,n=10),ARB treated group(AR group,n=10)and ACEI treated group(AE group,n=10).Rats were fed with high-calorie and high-fat diet and given RAS inhibitor drugs(valsartan 40mg/kg to the AR group and perindopril 4 mg/kg to the AE group)for eight weeks.Serum TG,free fatty acids(FFAs) lever and the fat content in liver were then measured with biochemical tests;insulin resistance was evaluated with euglycemic hyperinsulinemia clamp technique,the expression of UCP-2 and TGFβI in liver tissue were examind with immunohistochemical staining and AGT mRNA,UCP-2 mRNA and TGFβ1 mRNA were tested with RT-PCR.Results With the administration of RAS inhibitor drugs,following changes were observed.The levels of TG and FFAs and the fat content in liver decreased(P＜0.01 or P＜0.05),insulin resistance in high-fat fed rats was improved(P＜0.05),liver steatosis,inflammation and fibrosis were mitigated.The levels of UCP-2 decreased by 36.5%(P＜0.05)in AE group and 42.5%(P＜0.05)in AR group and TGFβ1 decreased by 37%(P＜0.05)in AE group and 41.6%(P＜0.05)in AR group as compared with the HF group with immunohistochemical staining.The expression of AGTmRNA decreased by 14.9%(P＜0.05)in AE group and 21%(P＜0.05)in AR group,UCP-2 mRNA decreased by 9%(P＜0.05)in AE group and 11%(P＜0.05)in AR group and TGFβ1 mRNA decreased by 17%(P＜0.05)in AE group and 19%(P＜0.05)in AR group as compared with the HF group with RT-PCR.Conclusions RAS blockade could improve insulin resistance,mitigate the liver injury of long term high-fat fed rats and have a protective effect on liver.The mechanism may be associated with the effects of improved insulin resistance,the interaction within RAS and the down-regulation of UCP-2 and TGFβ1 in liver tissue.

[ABSTRACT]OBJECTIVETo investigate the species distribution of the common inhaled allergens among the primary and middle school students in Beijing.METHODSA total of 1280 students who were randomly selected underwent 20 kinds of common allergen skin prick test. Skin prick test were positive in 495 students.RESULTS49.3% of the Beijing primary and secondary school students were positive for more than four kinds of allergens. The dust mites and fall pollen allergens were positive at the same time in 37.4% of the allergen positive students. The commonest three allergens were D. farina, D. pteronginus and Large seed fleabane pollen in urban area, and were dermatophagoides farinae, willow tree pollen and Large seed fleabane pollen in suburban area. The positive rate of skin prick test decreased with age.CONCLUSIONThe dust mites and fall pollen are the most important allergens in primary and middle school students in Beijing.

Objective To establish a simple and rapid method for the determination of 1,3-dideoxygalactonojirimycin in Bombycis Faeces, a potent glucosidase inihibitor, by HPLC. Methods A RP-HPLC method with fluorescence detection has been developed. Results The HPLC method developed in this research has a good reliability including accuracy and precision. The detection limit was less than 72 ng. Conclusion This method is sufficiently sensitive for determining 1,3-dideoxygalactonojirimycin in Bombycis Faeces and other related products.

Objective To optimize the extraction process for the effective fraction of Bushen Yizhi ( BSYZ) formula. Methods Yield of the effective fraction and contents of two marker compounds 2,3,5,4 -tetrahydroxystilbene-2-O-β-D-glucoside and osthole assayed by high performance liquid chromatography (HPLC) were used as the optimizing indexes, and weighted coefficient of the indexes was analyzed by analytic hierarchy process ( AHP). Ratio of liquid-to-solid, extraction time, and extraction times were used to screen the optimal conditions by orthogonal test. Results The optimized extraction process of the effective fraction of BSYZ formula was as follows: extracting with 8-fold water for three times, and boiling for 1.5 hours each time. The verification test showed that the comprehensive scores of the optimized extractive process were higher than those obtained in the orthogonal test. Conclusion The optimized extraction process and conditions are practical in the manufacture of the effective fraction of BSYZ formula.