Effect of noninvasive, positive pressure ventilation on patients with severe, stable chronic obstructive pulmonary disease: a meta-analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This meta-analysis evaluated the effect of noninvasive, positive pressure ventilation on severe, stable chronic obstructive pulmonary disease (COPD).</p><p><b>METHODS</b>PUBMED, CNKI, Wanfang, EMBASE and the Cochrane trials databases were searched. Randomized controlled trials of patients with severe, stable COPD and receiving noninvasive positive pressure ventilation, compared with sham ventilation or no ventilation, were reviewed. The mortality, physiological and health related parameters were pooled to yield odds ratio (OR), weighted mean differences or standardized mean differences (SMD), with 95% confidence interval (CI).</p><p><b>RESULTS</b>Eight parallel and three crossover randomized controlled trials met the inclusion criteria. Pooled analysis for parallel, randomized controlled trials showed noninvasive positive pressure ventilation: (1) Did not affect the 12- or 24-month mortality (OR 0.82, 95%CI: 0.48 to 1.41); (2) Improved the arterial carbon dioxide tension (SMD -0.88, 95%CI: -1.43 to -0.34); (3) Did not improve forced expiratory volume in one second (SMD 0.20, 95%CI: -0.06 to 0.46), maximal inspiratory pressure (SMD 0.01, 95%CI: -0.28 to 0.29) or 6-minute walk distance (SMD 0.17, 95%CI: -0.16 to 0.50); (4) Subgroup analysis showed noninvasive positive pressure ventilation improved the arterial carbon dioxide tension in hypercapnic patients. Pooled analysis for crossover randomized controlled trials did not show improvement in arterial blood gas or forced expiratory volume in one second with noninvasive positive pressure ventilation.</p><p><b>CONCLUSIONS</b>Noninvasive positive pressure ventilation improves the arterial carbon dioxide tension but does not improve the mortality, pulmonary function, or exercise tolerance and should be cautiously used in severe stable chronic obstructive pulmonary disease.</p>

Study of molecular subtypes of biotype 1A Yersinia enterocolitica in Shandong province from 2008 to 2009 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the molecular subtypes of 73 strains of Yersinia enterocolitica biotype 1A isolated in Shandong province by PFGE, and thereby to analyze the relationship between PFGE typing and biological characteristics.</p><p><b>METHODS</b>Seventy-three strains of Yersinia enterocolitica biotype 1A were isolated from animal feces and meat products in Gaomi city and Wulian county in Shandong province from 2008 to 2009. Motility test, serum agglutination and virulent genes detection by PCR were used to learn the biological characteristics of the isolated strains. The molecular subtypes were determined by PFGE, whose relationships with motility, serotypes and virulent genotypes were also analyzed.</p><p><b>RESULTS</b>Out of the 73 strains of Yersinia enterocolitica, 5 showed medium-active motility while the other 68 showed well-active motility. The dominated serotypes were O:5(17/73) and O:8(14/73), followed by O:9(5/73) and O:7, 8(1/73), and there was no O:3 serotype found. Meanwhile, 36 strains couldn't be serotyped. All the strains were negative with the gene ail, ystA, yadA and virF, yet the positive rate of ystB gene was 72.6% (53/73). The 73 strains of Yersinia enterocolitica isolated could be subtyped into 54 PFGE patterns (K6GN11SD0001-K6GN11SD0054), most of which only had 1 or 2 isolated strains, and no pattern was dominant. The strains in the same or similar cluster were from different hosts; each serotype and toxic genotype scattered in the clustering trees, without specific correlation with PFGE subtypes. 4 out of 5 strains, which showed medium-active motility, belonged to one branch, with the similarity coefficient at 80.9% - 100.0%; while all the toxic genotype belonged to type B.</p><p><b>CONCLUSION</b>Biotype 1A Yersinia enterocolitica has many clones, whose PFGE types had relations with motility, but no relations with virulent genotype and host.</p>