Objective To screen and identify the aptamers of the recombinant transpeptidase domain of PBP2a(penicillin binding protein 2a ,PBP2a) .Methods By using the recombinant transpeptidase domain of PBP2a as the screening target ,oligonucle-otides which were capable of specifically binding to the protein were screened by a random oligonucleotide library through the stem -atic evolution of ligand by exponential enrichment (SELEX )technique .The ssDNA was cloned and sequenced ,and the secondary structure of aptamer clones was predicted with mfold program .Results After 11 cycles of the selection ,the aptamers which were capable of binding to PBP2a with high affinity have been selected .40 clones from the 8 and 10 cycles were selected randomly and se-quenced .The aptamers obtained had no obvious homology according to their sequences by the sequence alignments ,and the 40 aptamers were classified to three groups according to their secondary structures .The aptamer 13 was found to be specific for the target protein with the highest affinity .Conclusion Aptamers for the recombinant transpeptidase domain of PBP2a with high affili-ty and specificity were successfully screened by SELEX ,which lays a foundation for exploring new ways of diagnosis and treatment of MRSA infection .

Objective To investigate the change and clinical value of serum cystain C(CysC)level in the patients with HBeAg-negative chronic hepatitis B(CHB).Methods 212 cases of CHB in our hospital were selected and divided into the HBeAg-negative group and the HBeAg-positive group according to the HBeAg status.105 healthy individuals at the same time were enrolled as the control group.The levels of serum CysC,ALT,AST,Cr,BUN and HBV DNA in 3 groups were detected and compared.The corre-lations between serum CysC with AST,AST,Cr,Bun,HBV DNA were analyzed by the Pearson correlation analysis.Results The mean CysC level in the HBeAg-negative group was (1 .40±0.36)mg/L,which was higher than (0.93±0.12)mg/L in the control group and (0.96±0.18)mg/L in the HBeAg-positive group,the differences between them was statistically significant(P <0.05). The CysC was significantly positively correlated with serum Cr level in the HBeAg-negative group(r=0.840,P <0.01).Conclusion The CysC level might be used as an effective index for monitoring the early kidney injury in the patients with HBeAg-negative CHB,which has important significance in the prevention and treatment of HBeAg-negative CHB.

Drug-resistant tuberculosis (DR-TB) has been a serious global public health problem. There is an urgent need in new drug development for drug-resistant Mycobacterium tuberculosis (MTB). Bedaquiline (Bdq) is a new antituberculous drug belonging to the diarylquinoline class that efficiently inhibits the adenosine triphosphate synthase enzyme of MTB, now is one of the core drugs for the treatment of DR-TB. Bdq can significantly improve the negative rate of sputum culture and reduce the mortality with good safety and tolerance, and it can also shorten the course of treatment for patients with tuberculosis and save costs. This article reviews the efficacy, safety, tolerability and treatment-related issues of Bdq-containing regimens for DR-TB.

Hypertension is the leading risk factor for global mortality and morbidity and those with hypertension are more likely to develop severe symptoms in cardiovascular and cerebrovascular system, which is closely related to abnormal renin-angiotensin system and elabela/apelin-apelin receptor (APJ) axis. The elabela/apelin-APJ axis exerts essential roles in regulating blood pressure levels, vascular tone, and cardiovascular dysfunction in hypertension by counterbalancing the action of the angiotensin II/angiotensin II type 1 receptor axis and enhancing the endothelial nitric oxide (NO) synthase/NO signaling. Furthermore, the elabela/apelin-APJ axis demonstrates beneficial effects in cardiovascular physiology and pathophysiology, including angiogenesis, cellular proliferation, fibrosis, apoptosis, oxidative stress, and cardiovascular remodeling and dysfunction during hypertension. More importantly, effects of the elabela/apelin-APJ axis on vascular tone may depend upon blood vessel type or various pathological conditions. Intriguingly, the broad distribution of elabela/apelin and alternative isoforms implicates its distinct functions in diverse cardiac and vascular cells and tissue types. Finally, both loss-of-function and gain-of-function approaches have defined critical roles of the elabela/apelin-APJ axis in reducing the development and severity of hypertensive diseases. Thus, targeting the elabela/apelin-APJ axis has emerged as a pre-warning biomarker and a novel therapeutic approach against progression of hypertension, and an increased understanding of cardiovascular actions of the elabela/apelin-APJ axis will help to develop effective interventions for hypertension. In this review, we focus on the physiology and biochemistry, diverse actions, and underlying mechanisms of the elabela/apelin-APJ axis, highlighting its role in hypertension and hypertensive cardiovascular injury and dysfunction, with a view to provide a prospective strategy for hypertensive disease therapy.

Tuberculous meningitis is the most common and serious type of central nervous system tuberculosis, with high mortality and disability rate, which has attracted extensive attention of global public health. The high mortality rate and disability rate of tuberculosis meningitis may be related to its lack of specific clinical and imaging characteristics, insufficient attention from clinicians, lack of early sensitive and specific diagnostic testing techniques, delay in treatment, and restricted penetration of anti-TB drugs into the blood-brain barrier or/and MDR-TB, etc. This article reviews the disease burden of TBM, chemotherapy drugs and regimens, anti-inflammatory agents, aspirin, interventional and surgical treatment to provide reference for clinical management of this disease.

The global trends of nontuberculous mycobacteria (NTM) infection and disease are both rising. Nontuberculous mycobacterial disease(NTMD) is a worldwide health burden associated with increasing morbidity, mortality, and economic costs. Antibiotic therapy is the mainstay of treatment for NTMD.Mycobacterial pathogens are intrinsically resistant to many available antibiotics, making treatment extremely challenging, especially in immunocompromised individuals and patients with underlying chronic lung conditions. Even with lengthy therapy and the use of a combination of antibiotics, only less than half NTMD patients can achieve clinical treatment success, so it is urgent to develop novel anti-NTM antibiotics. This article reviews the research progress on the medication of nontuberculous mycobacterial diseases.

Objective To evaluate the diagnostic efficacy of Kwak and ACR( 2017 ) thyroid imaging reporting and data systems ( T I‐RADS ) for thyroid nodules . Methods Cases of thyroid nodule who underwent surgery from January 2015 to M arch 2018 in 15 hospitals in Sichuan province were collected and the ultrasonographic features of thyroid nodules were retrospectively analyzed by trained senior ultrasound physicians using Kwak and ACR T I‐RADS classification methods . Totally ,12 712 thyroid nodules were observed ,7 023 thyroid nodules in 7 023 cases with complete ultrasound and surgical and pathological data were eventually enrolled in the study . T hyroid nodules with solid ,hypoechoic or very hypoechoic ,tall/wide ratio ≥ 1 , margin ill‐defined and microcalcification were classified as malignant signs of ultrasound . M alignant percentage was calculated and diagnostic tests were performed . Results ① T here was a statistical difference between the benign and malignant nodules in the two types of T I‐RADS classification ( P＜0 .01) . ② T he area under ROC curve of Kwak and ACR in the diagnosis of malignant nodules were 0 .89 and 0 .84 ,respectively . T he Youden index of Kwak and ACR were 0 .66 and 0 .57 ,respectively . ③Taking Kwak T I4B and ACR T R4 as critical points for malignancy ,the sensitivity ,specificity ,positive predictive value and negative predictive value of Kwak T I 4B were 75 .0% ,90 .9% ,83 .2% ,and 85 .9% , respectively . T he accuracy of Kwak T I4B was 84 .9% ; T he sensitivity ,specificity ,positive predictive value and negative predictive value of ACR T R4 were 88 .2% ,68 .9% ,62 .9% ,and 90 .8% ,respectively . T he accuracy of ACR T R4 was 76 .2% . T he Kappa value of Kwak TI4B and ACR T R4 was 0 .52 . T he χ2 value of Kwak T I4B and ACR T R4 was 2 174 .6 ( P ＜ 0 .01 ) . Conclusions T he diagnostic values of two T I‐RADS classification methods for thyroid malignant nodules are high . T he overall efficiency of Kwak T I‐RADS classification method is better than that of ACR TI‐RADS classification method .