Search

A new polythiophene-based optical probe, namely PTS, was designed and prepared for detection and quantification of the water present in organic solvents. PTS exhibited sensitive and fast absorption and fluorescence signaling response to the changes of water content in tetrahydrofuran (THF), N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc) due to the water-induced interpolymer-stacking aggregation as demonstrated by dynamic light scattering (DLS) analysis. The fluorescence intensity of PTS at 550 nm linearly reduced as a function of the water content in detection ranges of 0–30% (v/v) in THF, 0–10% in DMF and 0–10% in DMAc with the limit of detection (LOD) for water being 0.034% (v/v) in THF, 0.013% (v/v) in DMF, and 0.014% (v/v) in DMAc, respectively. Additionally, PTS-incorporated test paper was fabricated to successfully achieve naked-eye detection of water in DMF and DMAc. PTS was further applied to estimate the water content in real samples, convincingly demonstrating that our method was comparable with the standard Karl Fischer titration.

For a long time, the serious mismatch between negative pressure and drainage parameters of underground gas drainage has been the main reason for the standing engineering problems in coal mines, such as low gas drainage concentration, fast decay, and low-utilization rate. Aiming at these problems, an innovative method by adding micro-frequency conversion drainage pumps and electronically controlled valves at the key nodes of the conventional pipe network system of gas drainage and the joint quantitative regulation of underground regulation facilities and surface drainage pumps based on the intrinsic correlation between the drainage parameters and negative pressure is proposed in this paper to solve the difficulty of how to regulate increasing pressure or resistance in the on-site gas-drainage system and to realize energy matching in the whole drainage system on demand. For this method, the study further defines the safety and efficiency criteria of gas drainage, proposes the adaptive control strategy of gas-drainage parameters, and establishes the adaptive control model based on particle swarm optimization. The model took the safety and efficiency criteria of gas drainage as the constraint conditions and the maximum gas-drainage flow or concentration as the objective function to adaptively adjust the operating conditions of drainage pumps, micro-frequency conversion drainage pumps, and electric control valves to realize the adaptive regulation of gas-drainage parameters. Finally, based on the adaptive control strategy and model of gas-drainage parameters, the numerical simulation research was carried out through Comsol with Matlab. The results show that the gas-drainage concentration and high-concentration drainage period can be increased many times, and the adaptive drainage parameters of valves and micro pumps can be adjusted intelligently, which provides a theoretical basis for the intelligent field implementation of gas.

To study the floor deformation and failure characteristics in fully mechanized caving of extra-thick coal seam of 8209 working face in Tongxin Coal Mine was selected as the background, and the strain induction method was used to perform the field measurement. According to the variation trend of different strain sensors of coal seam floor, the deformation and failure depth of coal seam floor was determined to be between 19.8 m and 21.9 m. The distribution characteristics of mining ground pressure in the horizontal direction of floor were explored, and it was found that the periodic weighting step distance of floor was far less than that of roof. At the same time, based on the engineering geological model and similarity theory of 8209 working face, a physical model test of similar materials in mining floor was tested. Through the macroscopic model of mining floor crack expansion and the change in stress increment of four monitoring sections, it was found that the closer the coal seam, the greater the vertical stress increment, and the smaller the change towards the deep. The vertical stress increment of floor rock mass 22 m away from the coal seam is no longer affected. Therefore, it was inferred that the failure depth of mining floor in this working face is no more than 22 m, consistent with the field measurement results. The results show that the extra-thick coal seam in fully mechanized caving has an important cushioning effect on the propagation of floor mining pressure.

The aim of this study is to remedy the existing problems in the prediction methods of water inrush from the mining coal seam floor. This paper analyzes a large number of water inrush cases and proposes that there are four main factors, namely water pressure and water abundance of the confined karst aquifer in the mine floor, the lithological thickness and characteristics of different structures of aquiclude in the mine floor, the geotectonic characteristics of the aquifer and aquiclude, and mining ground pressure, which affect water inrush from the mining coal seam floor. Based on structural and damage mechanics, a mechanical model of homogeneously fractured weak rock stratum is established for the water-impermeable layer of the floor, 354 points of water inrush are used to investigate and analyze, critical curve equation of P vs. M of mine floor is determined and the primary factor that affects water inrush from the mine floor is obtained. Combined with the geological structure characteristics, the three-grade evaluation and prediction model is established for water inrush from mining coal seam floor. The results can be used toward a new evaluation and prediction method of water inrush from the mine floor.

BACKGROUND: Tuberculous pleural effusion (TPE) is the most common extrapulmonary manifestation which still has lasting effect on lung function, however conventional diagnostic tests for TPE register multiple limitations. OBJECTIVES: This study aims to investigate diagnostic efficacy of the interferon gamma release assay (IGRA: T-SPOT.TB) in TPE patients of different characteristics comparing to adenosine deaminase (ADA), in order to clarify its appropriate setting in clinical diagnosis.METHODS: We performed a prospective, single-centre study including all suspected pleural effusion patients consecutively from June 2015 to October 2018. By using receiver operating characteristic (ROC) curves, technical cut-offs for all enrolled participants were determined, and the utility of IGRA for pleural fluid (PF) was analysed. We obtained the independent risk factors using logistic regression analysis for TPE and evaluated the performance of the T-SPOT assay stratified by risk factors in comparison to ADA.RESULTS: A total of 601 individuals was consecutively recruited. The maximum of early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) in the PF T-SPOT assay had the best diagnostic efficiency in our study, with a sensitivity of 83.0% and a specificity of 83.1%. The corresponding cut-off value was 466 SFCs/106 mononuclear cells, which was equal to ADA (0.885 vs 0.887, P=0.957) and superior to PB. Among the TPE patients with low ADA (PPP=0.001) were independently associated with the risk of TB by multivariate logistic regression analysis. Notably, when stratified by risk factor, the sensitivity of PF T-SPOT was superior to the sensitivity (76.5% vs. 23.5%, P=0.016) for ADA and had noninferior specificity (84.4% vs. 96.9%, P=0.370).CONCLUSIONS: In conclusion, the overall potency of the PF T-SPOT assay is equal to that of ADA for diagnosing TPE. In addition, the PF T-SPOT assay can effectively discriminate TPE patients whose ADA is lower than 40 IU/L and is extremely superior to ADA in unconventional TPE patients (age≥45 yrs, female or BMI≥22). The PF T-SPOT assay is an excellent choice to supplement ADA to diagnose TPE.

BACKGROUND: Interferon Gamma Release Assay (IGRA) is still controversial in differentiating tuberculous pleural effusion (TPE), through recommended by World Health Organization (WHO) for identification of latent tuberculosis infection. OBJECTIVES: Aim to in comparison to Adenosine deaminase (ADA), evaluate the IGRA (T-SPOT.TB) diagnostic efficacy for TPE patients of different characteristics, to clarify its appropriate scene in clinical diagnosis. METHODS: A prospective, single-centre study including all suspected pleural effusion patients consecutively from June 2015 to October 2018. Through receiver operating characteristic (ROC) curves, all enrolled participants were determined technical cut-off and the utility of IGRA for pleural fluid (PF). Obtain the independent risk factors by logistic regression analysis for TPE, and evaluate the performance of T-SPOT stratified by risk factors, in comparison to ADA. RESULTS: A total of 601 individuals were consecutively recruited. The maximum of early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) in PF T-SPOT had the best diagnostic efficiency in our study, with a sensitivity of 83.0% and a specificity of 83.1%, corresponding cut-off value is 466 SFCs/10 6 mononuclear cells, which was equal to ADA (0.885 vs 0.887, P=0.957) and superior than in PB; Among the TPE patients with low ADA(45yrs, female or BMI≧22). PF T-SPOT assay is an extremely good choice to supplement ADA to diagnose TPE.

Background Tuberculous pleural effusion (TPE) is the most common extrapulmonary manifestation and may have lasting effect on lung function. However conventional diagnostic tests for TPE register multiple limitations. This study estimates diagnostic efficacy of the interferon gamma release assay (IGRA: T-SPOT.TB) in TPE patients of different characteristics. Methods We performed a prospective, single-centre study including all suspected pleural effusion patients consecutively enrolled from June 2015 to October 2018. Through receiver operating characteristic (ROC) curves, technical cut-offs and the utility of T-SPOT on pleural fluid (PF) were determined and analysed. Logistic regression analysis was performed to obtain the independent risk factors for TPE, and evaluated the performance of the T-SPOT assay stratified by risk factors in comparison to ADA. Results A total of 601 individuals were consecutively recruited. The maximum spot-forming cells (SFCs) of early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) in the PF T-SPOT assay had the best diagnostic efficiency in our study, which was equal to ADA (0.885 vs 0.887, P = 0.957) and superior to peripheral blood (PB), with a sensitivity of 83.0% and a specificity of 83.1% (The cut-off value was 466 SFCs/106 mononuclear cells). Among the TPE patients with low ADA (P P P = 0.001) were independently associated with the risk of TB by multivariate logistic regression analysis. Notably, when stratified by risk factor, the sensitivity of PF T-SPOT was superior to the sensitivity for ADA (76.5% vs. 23.5%, P = 0.016) and had noninferior specificity (84.4% vs. 96.9%, P = 0.370). Conclusions In conclusion, the PF T-SPOT assay can effectively discriminate TPE patients whose ADA is lower than 40 IU/L and is superior to ADA in unconventional TPE patients (age ≥ 45 yrs., female or BMI ≥ 22). The PF T-SPOT assay is an excellent choice to supplement ADA to diagnose TPE.

Room- and elevated-temperature wear tests were conducted using a pin-on-disk testing machine to study wear behavior of Mg97Zn1Y2 alloy and role of long-period-stacking-ordered (LPSO) structure phase in mild–severe wear transition (SWT). Variation of wear rate exhibited a three-stage characteristic with load at various test temperatures, i.e., a gradual increasing stage, a slightly higher plateau stage, and a rapid rising stage. The wear mechanisms in the three stages were identified using scanning electron microscope (SEM), from which the first stage was confirmed as mild wear, and the other two stages were verified as severe wear. The interdendritic LPSO structure phase was elongated into strips along the sliding direction with Mg matrix deformation in the subsurface, plate-like LPSO structure phase precipitated at elevated temperatures of 150 and 200 °C. The fiber enhancement effect and precipitation effect of LPSO structure phase resulted in a little difference in wear rate between the first and second stages, i.e., a masking effect on SWT. Microstructure and microhardness were examined in the subsurfaces, from which the mechanism for SWT was confirmed to be dynamic recrystallization (DRX) softening. There is an apparently linear correlation between the critical load for SWT and test temperature, indicating that SWT is governed by a common critical DRX temperature.

Background. Treatment response for the Mycobacterium abscessus (M. abscessus) lung disease remains far from satisfying. An effective regimen is needed to solve the problem. Methods. We retrospectively reviewed the medical records of all patients with M. abscessus lung disease who received antibiotics regimen at Beijing Chest Hospital Affiliated to Capital Medical University between July 1, 2010, and February 1, 2018. Patients were administered a conventional antibiotics regimen (including macrolide and moxifloxacin, along with an initial 12-week course of low-dose cefoxitin and amikacin) or intensified regimen (including a higher dosage of cefoxitin and linezolid besides conventional drugs), respectively. The time to sputum-culture conversion and proportion of sputum-culture conversion in liquid broth were investigated to evaluate the efficacy and evaluation of safety by performing the classification of adverse events according to the Division of AIDS, National Institute of Allergy and Infectious Disease. Patients were followed for 18 months from baseline. Results. In the conventional regimen group, the sputum conversion rate at 18 months was 29.4% (10/34), and the median time until sputum conversion was 2 months (IQR, 1-2 mo). Furthermore, in the intensified regimen group, the sputum conversion rate was 81.3% (13/16), and the median time until sputum conversion was 1 month (IQR, 1-1 mo). Leukopenia and drug-induced hepatotoxicity occurred more frequently in the intensified regimen group in contrast with the conventional regimen group patients. However, only 1 adverse event in the intensified regimen group was classified as severe adverse event. Conclusions. The intensified regimen could improve sputum conversion of M. abscessus lung disease compared with conventional regimen, but close safety surveillance is necessary to monitor adverse events.

Background Interferon-gamma release assay (T-SPOT.TB) has the theoretical possibility of discriminating TB from most non-tuberculous mycobacteria (NTM) infections, but there are limited reports on the use of T-SPOT.TB for diseases due to NTM in high TB burden country. The aim of the present study was to assess the utility of T-SPOT.TB in patients with NTM pulmonary disease. Methods Clinical parameters and laboratory characteristics of patients with NTM pulmonary disease between July 2011 and Jan 2017 were investigated retrospectively and comprehensively reviewed. Results A total of 127 patients with NTM pulmonary disease were retrospectively reviewed. Seven NTM species were isolated from 115 patients, and the most common species were M. intracellulare (48.7%, 56/115) and M. abscessus (34.8%, 40/115). NTM isolates were mainly prevalent in people aged 50 years or older (73.0%). The overall positive rate of T-SPOT.TB test was 29.6% (24/81). In patients infected with NTM sharing the RD1 region of Mycobacterium tuberculosis (M. TB), 50% (3/6) were positive in the T-SPOT.TB test, whereas 28.0% (21/75) was positive in the group with NTM not sharing the RD1 region of M. TB. No significant difference was detected in the positive rate of T-SPOT.TB between definite (28.3%, 15/53) and probable disease (32.1%, 9/28). Conclusions Our data indicated a relatively high positive rate of T-SPOT.TB test in patients infected with NTM not sharing the RD1 region of M. TB. Thus, T-SPOT.TB test displays a limited ability in differentiating TB infection from NTM disease in a high TB burden country.

Magmatic intrusions in coal-bearing strata can significantly change the physical and chemical properties of the intruded coal. Lamprophyre intrusions are extensive in coal seams 3–5 and 8 of the Carboniferous-Permian coal-bearing strata in the southeastern and southwestern regions of the Tongxin Minefield, Datong Coalfield, China. They appear primarily as sills of varying magnitudes, with thicknesses ranging from 0.15 to 23.51 m. In this area, coals can be classified as unaffected (normal geothermal gradient) and intrusion-affected. Unaffected coals are of high-volatile bituminous rank, with values of maximum vitrinite reflectance ranging from 0.7 to 0.9%, whereas intrusion-affected coals have values of maximum vitrinite reflectance ranging from 0.9 to 7.2%. A marked decrease in the degree of coalification can be observed with increasing distance from the lamprophyre intrusions. Near the intrusion-coal contacts, high-volatile bituminous coals have been thermally altered to form natural coke. The carbonate contents in intrusion-affected coals (0.2–46.1%) are significantly higher than those of the unaffected coal (0–2.0%). The coalbed gases of coal seams 3–5 and 8 are highly variable in both their molecular compositions and overall gas contents. Their CO2 volumes vary from 0.01 to 6.55 m3/t (daf); higher CO2 values are found in the coals affected by intrusions, and roughly decrease with increasing distance from the lamprophyre igneous intrusions toward the central region of the minefield. These variations in gas compositions are mainly related to magmatic activity. The coalbed gas contents in coal seams 3–5 and 8 range from 1.48 to 16.43 m3/t (on a dry, ash-free basis). The positive correlation observed between gas content and the ratio of CO2/CH4 + CO2 occurs only in intrusion-affected coals. Lamprophyre intrusions have negative effects on CH4 content in the study area. Since CO2 has a higher adsorption capacity than CH4, C2H6, and N2, the injection of gaseous CO2 derived from magmatic intrusions can effectively displace CH4-rich reservoir gas. In addition, there is a positive correlation between ash content and gas content on a dry, ash-free basis. Ash content is positively correlated with the ratio of CO2/CH4 + CO2 occurring only in intrusion-affected coals. Massive secondary carbonates that filled in the cleats act as small-scale impermeable seals, which provide a sealing effect both on gas contents and gas compositions during uplift.

Drug resistance to tuberculosis remains a major public health threat. Here, we report two cases of extended-spectrum extensively drug-resistant (XXDR) tuberculosis showing resistance to most first- and second-line agents. The results of a correlation of whole-genome sequencing (WGS) and phenotypic testing were discordant, suggesting that overreliance on WGS may miss clinically relevant resistance in extensively drug-resistant disease.

Purpose of this paper is to analyze different species’ proportion of nontuberculosis mycobacteria (NTM) and susceptibility to clarithromycin of different species. 278 clinical NTM isolates were identified into species by using 16S rRNA,rpoBandhsp65. Then clarithromycin susceptibility testing against different species was done separately, using microplate Alamar Blue assay. Finally, resistance isolates’erm(41)ofM. abscessuswere sequenced in order to analyze mechanisms for clarithromycin resistant. In this test, 131 isolates (47%) belonged toM. aviumcomplex (MAC), and 70 isolates (25%) belonged toM. abscessus. Nearly all theM. abscessussubsp.abscessusresistant to clarithromycin had T28 inerm(41). However, all theM. abscessussubsp.abscessussusceptible to clarithromycin had C28 inerm(41). In this study, we find that MAC was the most common pathogens of NTM, and the second one wasM. abscessus. However,M. chelonei, M. fuerth, andM. gordonwere rare. Clarithromycin had a good inhibition activity against all the NTM species exceptM. abscessussubsp.abscessus. Theerm(41)genotype is of high relevance to clarithromycin resistance.

Aiming to reduce the high mining stress observed in large-space roof structures during mechanized mining of thick coal seams, a control technique based on protective-seam mining is proposed. This technique was used to investigate the 8108 working face of the No. 3–5 thick coal seam of the Tashan mine located in the Datong area of Shanxi, China, by means of simulations and field measurements. The numerical simulation revealed that the No. 3–5 coal seam undergoes expansion and deformation, accompanied by stress relief due to the mining of the overlying No. 4 coal seam. The physical simulation demonstrated that mining the protective seam changes the structural characteristics of the overlying strata in advance and reduces the integrity of the roof in the No. 3–5 coal seam. Field measurements showed that the support loads in the 8108 working face are significantly weaker than those in the adjacent 8107 working face, where protective-seam mining was not performed. In the absence of high resistance on the support and distinct periodic weighting characteristics, the rock masses around the 8108 working face and roadway could be easily supported.

Summary Objectives To separate Mycobacterium abscessus subsp. bolletii from Mycobacterium abscessus subsp. abscessus using species identification, and to investigate the in vitro activity of amikacin, cefoxitin, imipenem, levofloxacin, moxifloxacin, clarithromycin, azithromycin, and linezolid against Mycobacterium abscessus . Methods Seventy M. abscessus isolates, previously identified by 16S rRNA sequencing, were further identified by comparative sequence analysis of rpoB and hsp65 . Drug susceptibility testing was conducted using the microplate Alamar Blue assay in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines and interpreted using CLSI breakpoints. Results Of the 70 strains, 45 (64%) were M. abscessus subsp. abscessus and 25 (36%) were M. abscessus subsp. bolletii . The majority of M. abscessus isolates were susceptible to azithromycin, amikacin, linezolid, and imipenem ( M. abscessus subsp. abscessus : 93%, 98%, 93%, and 73%, respectively; M. abscessus subsp. bolletii : 96%, 96%, 80%, and 68%, respectively). Approximately half of the M. abscessus isolates were moderately susceptible to cefoxitin and moxifloxacin ( M. abscessus subsp. abscessus 53% and 49%; M. abscessus subsp. bolletii 72% and 68%). Nearly all the M. abscessus isolates were resistant to levofloxacin ( M. abscessus subsp. abscessus 96%, M. abscessus subsp. bolletii 100%). Inducible clarithromycin resistance was found in M. abscessus . After 14 days of incubation, 83% M. abscessus subsp. abscessus and 36% M. abscessus subsp. bolletii were resistant to clarithromycin. Conclusions Using rpoB and hsp65 , M. abscessus subsp. bolletii could be distinguished from M. abscessus subsp. abscessus. Amikacin and azithromycin showed excellent activity against M. abscessus in vitro. Imipenem, linezolid, cefoxitin, and moxifloxacin also showed good activity. Levofloxacin was inactive against M. abscessus. Although clarithromycin showed excellent activity against M. abscessus on day 3, inducible resistance occurred, and after 14 days clarithromycin showed little activity against M. abscessus subsp. abscessus , but still had good activity against M. abscessus subsp. bolletii .

The clinical relevance of non-tuberculous mycobacteria (NTM) has been reported to be different dramatically by species or by regions, however, no such evaluation has been performed in China.A retrospective study was performed in Beijing Chest Hospital. All the NTM strains isolated from respiratory specimens in the past 5 years, and patients’ clinical records (symptoms and radiographic information etc.) were investigated. The clinical relevance was evaluated according to the criteria recommended by the American Thoracic society. Totally 232 NTM strains were recruited, among them, M. intracellulare was the dominant species (40.5%), followed by M. abscessus (28.4%). 109 patients, with 185 total isolates, had full clinical records available for review. 84.4% (38/45), 85.7% (24/28%) and 63.6% (7/11) of patients with isolation of M. intracellulare, M. abscessus and M. kansasii, respectively, were categorized as definite NTM disease. Whereas all the 10 patients with isolation of M. gordonae were defined as unlikely NTM disease. The majority of NTMs isolates yielded from respiratory specimens in Beijing Chest Hospital were clinically significant, and M. intracellulare and M. abscessus was the dominated species of NTM lung disease. NTM lung infections demonstrated some specific chest radiograph characteristics.

This study aimed to assess the performance of the GenoType MTBDRsl Line Probe Assay (LPA) for the detection of resistance to levofloxacin, amikacin, capreomycin and ethambutol on sputum specimens. Sputum samples from patients with smear positive multidrug-resistant tuberculosis, identified with GenoType MTBDRplus LPA, were further evaluated using the MTBDRsl LPA, while phenotypic drug susceptibility testing was used as control. Sputa with discordant outcomes were assessed by gene sequencing. 189 cases were included. The interpretability of the MTBDRsl LPA was 96.8%. The sensitivity and specificity of the MTBDRsl test were 82.5% and 91.5% for levofloxacin, 52.6% and 99.2% for amikacin, 58.1% and 97.7% for capreomycin, and 70.8% and 93.3% for ethambutol respectively. For the diagnosis of extensively drug-resistant tuberculosis, the sensitivity and specificity were 56.1% and 100%. The MTBDRsl LPA presents a specific screening tool to detect resistance to several key second-line anti-tuberculosis drugs and ethambutol in smear positive specimens.

A new composite two component grout comprised of modified urea–formaldehyde resin and cement was formulated to take account of the advantages and disadvantages of both the cement grout and the chemical grout. The new grout is designed for water blocking by reinforcing as well as seepage control by bore grouting. The A component consists of a modified urea–formaldehyde resin A component, some cement, and some water. The B component is an alkaline coagulant. An orthogonal test of four factors at three levels showed that gel time increased with increased water content and with urea–formaldehyde resin content. Gel time decreased at increased levels of alkaline coagulant. The A component of this new composite grout is stable over time. A mixed cross-over test showed that as the volume ratio of A to B increases the gel time falls at first but then increases. The solid strength decreases with increasing levels of the B component. The solid strength increases over time and becomes stable by the 28th day after mixing. The viscosity increases with increasing levels of resin A component. The increase is exponential and may be fit to: μ = 8.162e0.0286x. Keywords: Modified urea–formaldehyde resin A liquid, Grouting materials, Orthogonal test, Gel time, Solidification strength

The aim of this study was to explore the molecular mechanism of apoptosis in esophageal cancer cells induced by Isodon rubescens.The DNA-damage effect of Jaridonin was detected by single cell gel electrophoresis (SCGE). The p53 protein was determined by Western blot. GSH assay kit was employed to determine the GSH content in human esophageal cancer EC-1 cells. Intracellular levels of hydrogen peroxide (H2O2) or superoxide (O(2).-) were determined using the redox-sensitive probes 2', 7'-dichlorodihydrofluorescein diacetate (DCF) or dihydroethidium (DHE), and the fluorescence signal was assayed by fluorescence microscopy and by flow cytometry.Jaridonin induced DNA damage in EC-1 cells remarkably. The olive tail moments (OTM) of control and 20, 40 µmol/L Jaridonin were 3.2, 45.2 and 89.0, respectively. Compared with the control, the differences were significant (P0.01 for both). Jaridonin resulted in extensive p53 up-regulation in the EC-1 cells. More importantly, the p53 up-regulation occurred as early as 2 h after Jaridonin incubation, and in a time-dependent manner (P0.05). p53 siRNA transfection inhibited apoptosis in the EC-1 cells, and the Jaridonin-induced apoptosis rate was reduced from 38.5% to 8.8%. Intracellular level of H2O2 was increased by Jaridonin, whereas the level of O(2).- was barely changed. The GSH content in EC-1 cells was reduced from (10.3 ± 1.6) nmol/mg protein to (4.6 ± 2.1) nmol/mg protein after 20 µmol/L Jaridonin incubation for 8 h, and it was further reduced with the increase of Jaridonin concentration. Jaridonin induced DNA damage, H2O2 accumulation and apoptosis were significantly attenuated in the presence of GSH, but Jaridonin showed little effect on normal human liver L-02 cells.Jaridonin selectively induces apoptosis in esophageal cancer EC-1 cells through H2O2-mediated DNA damage by depleting GSH.

To evaluate the method of differentiating Mycobacterium abscessus subsp. abscessus (subsp. M. abscessus) from Mycobacterium abscessus subsp. massiliense (subsp. M. massiliense), and to investigate the activity of different antibiotics in vitro.Sixty Mycobacterium abscessus (M. abscessus) isolates previously identified by using 16S rRNA sequence, were identified by comparative sequence analysis of rpoB and hsp65, and were divided into subsp. M. abscessus and subsp. M. massiliense. Two subspecies' resistant proportions were compared by chi-square test. Finally the relationship between clarithromycin resistance and erm(41) was analyzed.Of all the 60 M. abscessus isolates, 65% (39/60) belonged to subsp. M. abscessus, 35% (21/60) belonged to subsp. M. massiliense. 97% (38/39) subsp. M. abscessus and 95% (20/21) subsp. M. massiliense were susceptible to amikacin. 92% (36/39) subsp. M. abscessus and 95% (20/21) subsp. M. massiliense were susceptible to azithromycin. 74% (29/39) subsp. M. abscessus and 67% (14/21) subsp. M. massiliense were susceptible to imipenem. 46% (18/39) subsp. M. abscessus and 76% (16/21) subsp. M. massiliense were moderately susceptible to cefoxitin. 82% (32/39) subsp. M. abscessus were resistant to clarithromycin, and 95% (20/21) subsp. M. massiliense were susceptible to clarithromycin. Of all the 28 subsp. M. abscessus isolates which were sequenced suscessfully, 23 isolates were resistant to clarithromycin, and 22 isolates in them had T28 in erm(41), and the rest one had C28 in erm(41). However, all the 5 subsp. M. abscessus isolates which were susceptible to clarithromycin had C28 in erm(41).M. abscessus can be divided into subsp. M. abscessus and subsp. M. massiliense by using rpoB and hsp65. Amikacin, azithromycin and imipenem showed excellent inhibition activity against M. abscessus in vitro. Cefoxitin also showed a good inhibition activity. Clarithromycin had a poor inhibition activity against subsp. M. abscessus, but a good inhibition activity against subsp. M. massiliense. Erm(41) was related to clarithromycin resistance.

To investigate the susceptibility of Mycobacterium intracellulare isolates to clarithromycin, azithromycin and linezolid, and therefore to explore the possibility of using these drugs to treat Mycobacterium intracellulare diseases.The minimal inhibitory concentrations (MICs) of the 3 antibiotics against 76 Mycobacterium intracellulare isolates were determined by using microplate alamar blue assay (MABA).The MIC90 of clarithromycin against Mycobacterium intracellulare isolates was 2 mg/L. The proportion of susceptible, intermediate and resistant isolates to clarithromycin was 93.4% (71/76), 0.0% (0/76) and 6.6% (5/76), respectively. The MIC90 of azithromycin against the isolates was 32 mg/L. The proportion of susceptible, intermediate and resistant isolates to azithromycin was 94.7% (72/76), 0.0% (0/76) and 5.3% (4/76), respectively. The MIC90 of linezolid was 64 mg/L. The proportion of susceptible, intermediate and resistant isolates to linezolid was 32.9% (25/76), 22.4% (17/76) and 44.7% (34/76), respectively. Among the 5 isolates resistant to clarithromycin, 4 were resistant to azithromycin, and 2 were resistant to linezolid.Most of the Mycobacterium intracellulare isolates were sensitive to clarithromycin. High cross-resistance between clarithromycin and azithromycin was present, but some clarithromycin-resistant isolates were sensitive to linezolid.