An investigation of the risk factors of chronic obstructive pulmonary disease in natural population-based cohorts in China - a nested case-control study.

Background: Chronic obstructive pulmonary disease (COPD) has become one of the most significant chronic diseases in China. According to conventional wisdom, smoking is the pathogenic factor. However, current research indicates that the pathophysiology of COPD may be associated with prior respiratory system events (e.g., childhood hospitalization for pneumonia, chronic bronchitis) and environmental exposure (e.g., dust from workplace, indoor combustion particles). Dyspnea, persistent wheezing, and other respiratory symptoms further point to the need for pulmonary function tests in this population. Reducing the burden of chronic diseases in China requires a thorough understanding of the various factors that influence the occurrence of COPD. Methods: Using a cohort from the natural population, this study used nested case-control analysis. We carried out a number of researches, including questionnaire surveys and pulmonary function testing, in the Northwest and Southeast cohorts of China between 2014 and 2021. After removing any variations in the baseline data between patients and control subjects using propensity score matching analysis, the risk factors were examined using univariate or multivariate regression. Result: It was discovered that prior history of chronic bronchitis, long-term wheezing symptoms, and environmental exposure-including smoking and biofuel combustion-were risk factors for COPD. Dyspnea, symptoms of mobility limitation, organic matter, and a history of hospitalization for pneumonia at an early age were not significant in the clinical model but their incidence in COPD group is higher than that in healthy population. Discussion: COPD screening effectiveness can be increased by looking for individuals with chronic respiratory symptoms. Smokers should give up as soon as they can, and families that have been exposed to biofuels for a long time should convert to clean energy or upgrade their ventilation. Individuals who have previously been diagnosed with emphysema and chronic bronchitis ought to be extra mindful of the prevention or advancement of COPD.

Analysis of Drug-Resistance Characteristics and Genetic Diversity of Multidrug-Resistant Tuberculosis Based on Whole-Genome Sequencing on the Hainan Island, China.

Purpose: Given the high burden of Tuberculosis (TB) in China, the prevalence of multidrug-resistant tuberculosis (MDR-TB) is significant. Whole-genome sequencing (WGS) of Mycobacterium tuberculosis (MTB) enables the identification of lineages, drug-resistant mutations, and transmission patterns, offering valuable insights for TB control, clinical diagnosis, and treatment. Methods: We collected 202 MDR-MTB strains from 3519 suspected pulmonary TB patients treated at The Second Affiliated Hospital of Hainan Medical University between July 2019 and June 2021. Proportional drug-susceptibility testing was performed using 8 common anti-tuberculosis drugs. Subsequently, the genotypic drug resistance and genetic characteristics were analyzed by the WGS. Results: Lineages are identified by TB-profiler revealed 202 MDR-MTB strains, showcasing three predominant lineages, with lineage 2 being the most prevalent. Close genomic relatedness analysis and evidence of MTB transmission led to the formation of 15 clusters comprising 42 isolates, resulting in a clustering rate of 20.8%. Novelty, lineage 2.1 (non-Beijing) accounted for 27.2% of the MDR-MTB strains, which is rare in China and Neighboring countries. Regarding first-line anti-TB drugs, genes associated with rifampicin resistance, primarily the rpoB gene, were detected in 200 strains (99.0%). Genes conferring resistance to isoniazid, ethambutol, and streptomycin were identified in 191 (94.5%), 125 (61.9%), and 100 (49.5%) strains, respectively. Among the second-line drugs, 97 (48.0%) strains exhibited genes encoding resistance to fluoroquinolones. Comparing the results to phenotypic drug susceptibility-based testing, the sensitivity of WGS for detecting resistance to each of the six drugs (rifampicin, isoniazid, ethambutol, ofloxacin, kanamycin, capreomycin) was 90% or higher. With the exception of ethambutol, the specificity of WGS prediction for the remaining drugs exceeded 88%. Conclusion: Our study provides crucial insights into genetic mutation types, genetic diversity, and transmission of MDR-MTB on Hainan Island, serving as a significant reference for MDR-MTB surveillance and clinical decision-making.

Isolation, identification and drug sensitivity analysis of Mycobacteroides abscessus in a hospital in Hainan Province from 2014 to 2021 / 中国热带医学

@#Abstract: Objective　To identify the species of Mycobacteroides abscessus complex (MABC) in patients with pulmonary infection from the Second Affiliated Hospital of Hainan Medical University, and to investigate the species types, drug sensitivity and population distribution of MABC in pulmonary infection in Hainan. Methods　Respiratory tract specimens were collected from suspected tuberculosis patients who visited the Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2021 and cultured for Mycobacterium isolation. Non-tuberculous mycobacteria (NTM) strains were preliminarily identified by p-nitrobenzoic acid/thiophen-2-carbohydrazide (PNB/TCH) medium and DNA microarray chip, and then MABC and its subspecies were identified by hsp65 and rpoB gene sequencing. In vitro antimicrobial susceptibility test was performed by broth microdilution method. Results　A total of 3 025 respiratory specimens from suspected pulmonary tuberculosis patients were collected during the study period. Among the 123 patients with identified MABC isolates, 124 MABC strains were isolated and identified, including 74 strains of Mycobacteroides abscessus subsp. abscessus, 38 strains of Mycobacteroides abscessus subsp. massiliense and 12 strains of Mycobacteroides abscessus subsp. bolletii. Among them, 118 patients had single MABC subspecies infection, one patient had mixed infection with two MABC subspecies, two patients had mixed infection with MABC and other NTM, and two cases had mixed infection with MABC and M.tuberculosis. There were more female patients than male patients with a ratio of 1:0.64, and those aged 50 and above amounted to 76.42% (94/123, 95%CI: 67.93%-83.61%). There was no significant difference in age distribution between male and female patients (Z=-0.944, P=0.347). The drug susceptibility results showed that all MABC strains were sensitive to Tigecycline (TGC), with a resistance rate of 0.81% (1/124) to Amikacin (AK), and resistance rates of 6.45% (8/124), 32.26% (40/124), and 74.19% (92/124) to Cefoxitin (FOX), Linezolid (LZD), and Imipenem (IPM), respectively. For Clarithromycin (CLR), MABC showed induced resistance , and there was a statistically significant difference in the CLR (14D) resistance rates among the three subspecies (χ2=66.335, P<0.001). The resistance rates to Tobramycin (TOB), Doxycycline (DOX), Moxifloxacin (MFX), Ciprofoxacin (CIP), Trimethoprim/Sulfamethoxazole (TMP-SMX), and Amoxicillin/Clavulanic acid (AMC) were high, all >80%. Conclusion　 In Hainan Province, pulmonary infections with MABC are mainly caused by Mycobacteroides abscessus subsp. Abscessus, which show high rates of inducible resistance to CLR. Timely and accurate identification of MABC to subspecies and drug susceptibility testing are of significant important for clinical decision-making.

Construction of Molecular Transporter Based on DNA Structure Regulation.

This study aims to build a molecular transporter machine that is based on the microstructure regulation of DNA triplets, which can automatically search, load, target delivery, and unload target protein molecules. The design of the molecular transporter includes: (1) a DNA triplet, which can recognize and load of the target protein; (2) a similar DNA triplet realizing the target transport; and (3) the signal-indicating DNA, which is connected at the target destination to achieve fixation of the target protein at the target destination. The molecular transporter machine would provide research practice and theoretical guidance for the development of DNA-based molecular machines.