Objective To study the rapid detection of mycobacterium tuberculosis resistance to streptomycin by reverse dot blot hybridization technique. Methods The oligonucleotide probes of streptomycin-resistant genes (rpsL and rrs) were prepared and dropped on nitrocellulose membrane. The target DNA fragments of M. tuberculosis clinical isolates were labeled with biotin by PCR amplification, and then hybridized with the oligonucleotide probes on the membranes. PCR-SSCP and PCR-direct sequencing (PCR-DS) techniques were used to detect the target fragment of M.tuberculosis as control. Results In 53 M. tuberculosis clinical isolates, the consistent rate of three detection methods was 100%. Both the SSCP mapping of rpsL and rrs genes and the results of membrane hybridization in 9 drug-sensitive strains were identical to those in M. tuberculosis standard strain H37Rv. Of 44 streptomycin-resistant strains, 33 strains had AAG→AGG mutation at the codon 43 of rpsL gene, 6 strains had A→C mutation at the 513 site of rrs gene, 1 strain had A→T mutation at the 513 site of rrs gene, and the detection rate of the target genes mutation was 90 9%. In 53 M.tuberculosis clinical isolates, 40 resistant strains and 9 sensitive strains to streptomycin could be detected using dot blot hybridization and the consistent rate with the in vitro susceptibility test was 92 6%(49/53). Conclusion The reverse dot blot hybridization technique showed high sensitivity and specificity to detect Mycobacterium tuberculosis resistance to streptomycin. It possessed the simple and rapid characteristics, and could be used to detecte streptomycin-resistant M.tuberculosis clinical strains.

Objective To express mouse IFN-λ2 stably and study its biological activity. Methods Full-length of mIFN-λ2 cDNA was obtained by using RT-PCR from cells of mouse spleen stimulated by ve-sicular stomatitis virus(VSV) and then subcloned to eukaryotic expressing vector PCAGG-EGFP. The recom-binant was transfected into CHO cells. VSV * GFP-B16 system was used to measure the antivirus activity. The constructed cell line MDBK-Mxp-Luc was used to study the character of Mx1 protein induced by the mIFN-λ2. Results The recombinant pMD18-T-mIFN-λ2 was digested by two kinds of enzyme, Sac I and Xho I, to produce the fragment was of 582 bp, and of which the sequence analysis of sequence shows it was entirely consistent with the nucleotide sequences reported in GenBank. PCAGG-EGFP-mIFN-λ2 eukaryotic expressing vector was constructed successfully and expressed stably in CHO cells, and the mRNA of mIFN-λ2 was verified expressing in CHO-PCAGG-EGFP-mIFN-λ2 cell line by RT-PCR. The antivirus activity of in the supernatant secreted by the CHO-PCAGG-EGFP-mIFN-λ2 cell line was 10~4 AU/ml. The mIFN-λ2 pro-tein can could induce the expression of the antivirus protein Mx1, and the expression of Mx1 protein induced by mIFN-λ2 enhanced with time going, 9 to 12 hours achieved the peak, 24 hours vanished. Conclusion Gene cloning of mIFN-λ2 was successful. The eukaryotic expressing vector of mIFN-λ2 was constructed suc-cessfully and expressed stably in CHO cells, and its product has obvious antivirus activity in vitro. And the antivirus activity of the product was closely correlated with inducing expression of antivirus protein Mx1.

Objective:To evaluate the effect of lung recruitment maneuvers combined with individualized positive end-expiratory pressure(PEEP) on the degree of postoperative atelectasis in elderly patients undergoing laparoscopic surgery.Methods:One hundred and forty-three elderly patients, aged ≥65 yr, with body mass index of 18.5-30.0 kg/m 2, scheduled for elective laparoscopic surgery, were assigned to either individualized PEEP combined with recruitment maneuvers (group Ⅱ) or fixed PEEP (group Ⅰ) using a random number table method. PEEP was maintained at 6 cmH 2O starting from the beginning of procedure until the end of the procedure in group I. Individualized PEEP titration was performed after induction of anesthesia in group Ⅱ. The primary outcome measure was the 12-zone lung ultrasound score at 15 min after tracheal extubation. Other outcome measures were the occurrence of postoperative pulmonary complications within 7 days after surgery, Quality of Recovery-15 scale score on 3rd day after surgery, rate of unplanned admission to intensive care units, length of hospital stay, incidence of intraoperative hypoxemia, usage rate of intraoperative vasoactive drugs, and incidence of postoperative hypotension. Results:Compared with group Ⅰ, the lung ultrasound score, driving pressure and postoperative pulmonary complications were significantly decreased, the dynamic lung compliance was increased ( P<0.05 or 0.01), and no significant changes were found in the other parameters in group Ⅱ ( P>0.05). Conclusions:Individualized PEEP combined with recruitment maneuvers can reduce the degree of postoperative atelectasis in elderly patients undergoing laparoscopic surgery.

Purpose This study aims to observe the hemodynamic state of the carotid artery in healthy volunteers and diabetes patients via ultrasound vector flow imaging(V-Flow),and to quantitatively analyze the characterization of wall shear stress(WSS)in different degrees of atherosclerosis carotid artery.Materials and Methods This was a cross-sectional study.Forty four diabetic patients diagnosed in Sichuan Provincial People's Hospital from April 2019 to June 2019 were retrospectively analyzed.Routine carotid ultrasound examination and V-Flow imaging were performed on 44 diabetic patients(88 vessels)and 15 controls(30 vessels).According to the results of carotid ultrasound examination,diabetic patients were divided into normal intima-media thickness(IMT)group,IMT thickening group and plaque group.The differences of WSS in different parts of carotid artery between diabetic patients and controls were observed,and the changes of WSS in different groups of diabetic patients were further compared and analyzed.Results In this study,the WSS(including WSSmax and WSSmean)of the bifurcation and middle segment of the common carotid artery in diabetic patients were significantly lower than those in the normal control group(P=0.001,P=0.003).WSS at the bifurcation of common carotid artery was significantly smaller than that at the middle segment of common carotid artery in both normal control group and diabetic group(P=0.001).WSS at the bifurcation of common carotid artery in diabetic patients was changed with the severity of atherosclerosis(P=0.018 and P=0.043),and was highest in the plaque group[WSSmax(2.58±0.69)Pa;WSSmean(0.86±0.25)Pa],followed by IMT thickening group[(2.37±0.69)Pa;(0.77±0.35)Pa].The WSS was lowest in the normal IMT group[(2.13±0.52)Pa;(0.69±0.20)Pa].There was no significant difference in WSS of the middle segment of common carotid artery among the three groups(P>0.05).Conclusion The WSS in the bifurcation and middle section of common carotid artery in diabetic patients is lower than that in controls,and it changed with the increase of atherosclerosis degree.Therefore,the V-Flow technique of ultrasonic vector flow imaging has a certain value in evaluating the progression of carotid atherosclerosis in diabetic patients.

Humans ; Computed Tomography Angiography ; Deep Learning ; Coronary Angiography ; Coronary Artery Disease ; Tomography, X-Ray Computed ; Coronary Stenosis/diagnosis* ; Retrospective Studies ; Fractional Flow Reserve, Myocardial ; Predictive Value of Tests