Effect of smoking cessation on airway inflammation of rats with chronic bronchitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Smoking is the major cause of airway inflammation in chronic obstructive pulmonary disease (COPD), and smoking cessation is regarded as one of the important strategies for prevention and treatment of the inflammation. The inflammation of the chronic airway may be present and deteriorated even if the COPD patients stop smoking. Whether and how early smoking cessation affects the progress of inflammation is still obscure. This study was conducted to find the appropriate time for smoking cessation to terminate the airway inflammation in rats with smoke-induced chronic bronchitis.</p><p><b>METHODS</b>A rat model of COPD was established by passively inhaling smoke mixture. Fifty-four young male Sprague-Dawley rats were randomly divided into 9 groups with different periods of smoke exposure and different time points of cessation. The inflammation markers to be detected included inflammatory cells in the bronchoalveolar lavage fluid (BALF), the myeloperoxidose (MPO) activity, the morphologic changes and the expression of ICAM-1 on the airway epithelium.</p><p><b>RESULTS</b>When smoking was terminated at early stage, the inflammatory markers and related indexes were different from those of the typical chronic bronchitis group (group M7) (P < 0.01). The pathologic score of group SC7 (2 weeks of smoking cessation after occurrence of typical chronic bronchitis) was not different from that of group M7, and the level of ICAM-1 was still up-regulated (compared to group M7, P > 0.05). Meanwhile, most of inflammatory cells in BALF were neutrophils compared to other groups (P < 0.01). When smoking was terminated, the MPO activity was significantly lower than that of group M7 (P < 0.01).</p><p><b>CONCLUSIONS</b>Smoking cessation at early stage can effectively inhibit the inflammatory reaction of COPD. Once chronic bronchitis occurs, little could be improved by smoking cessation.</p>

Mitochondrial DNA mutation analysis in patients with mitochondrial myopathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To examine mitochondrial DNA mutations in mitochondrial myopathy.</p><p><b>METHODS</b>Three suspected cases of mitochondrial myopathy were examined by HE staining, histochemical staining methods and electron microscopy. The mutations in all 22 tRNA genes of mitochondrial genome were screened by polymerase chain reaction-single strand conformation polymorphism and DNA sequencing.</p><p><b>RESULTS</b>The three cases were diagnosed as mitochondrial myopathy. The examinations revealed that patient 1 had a homoplasmic A1627G mutation in tRNA-Val gene, and patient 2 had a heteroplasmic A1627G/A mutation in tRNA-Val gene, and patient 3 had two mutationsuone was homoplasmic T5554C mutation in tRNA-Trp gene, the other was heteroplasmic A10412C/A mutation in tRNA-Arg gene.</p><p><b>CONCLUSION</b>tRNA genes mutations of mtDNA might be one of the etiologies of mitochondrial myopathy.</p>

Polymorphism of the D4Z4 locus associated with facioscapulohumeral muscular dystrophy 1A in Shanghai population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the D4Z4 repeats on chromosome 4q35 in normal individuals in Shanghai and analysis the polymorphism of the D4Z4 locus.</p><p><b>METHODS</b>The length of D4Z4 repeats on chromosome 4q35 in 191 normal individuals in Shanghai was determined by pulsed-field gel electrophoresis and Southern blotting after double digestion with Eco RI and Bln I. The number of short D4Z4 repeats was counted after partial digestion with Kpn I.</p><p><b>RESULTS</b>Among 191 normal individuals in Shanghai, seventeen showed the size of D4Z4 fragments ranged from 22 to 34 kb, i.e. 8.9% of individuals had fewer numbers of D4Z4 repeats. Of these 17 individuals, sixteen showed the short D4Z4 fragment on chromosome 4q35, and one low D4Z4 fragment was correlated to 4q35--> 10q26 translocation.</p><p><b>CONCLUSION</b>The frequency of individuals having fewer numbers of D4Z4 repeats on chromosome 4q35 in Shanghai population is higher than that in Caucasian population although the short D4Z4 fragment on chromosome 4q35 is associated with facioscapulohumeral muscular dystrophy. These findings suggest that other factors may also contribute to facioscapulohumeral muscular dystrophy.</p>