Mycobacterium abscessus has been identified as an emerging pulmonary pathogen in humans. Previously, it was documented that a spontaneously formed rough variant of M. abscessus causes persistent and invasive infection in mice, while a smooth isogenic variant does not. However, little is known for immune responses elicited by M. abscessus variants artificially induced by culture conditions and their culture filtrate antigens. Thus, morphological variants of M. abscessus type strain (ATCC19977T) were generated by an acidic and low oxygen culture conditions. Overall comparison between the variant and its original smooth strain showed that the rough variant was less virulent than original smooth strain in murine bone-marrow derived macrophage. To understand the basis for the difference, the protein expression pattern in the culture filtrates of each strain was analyzed by 1-dimensional electrophoresis. Generally, the protein expressions were more influenced by pH conditions than oxygen pressures. Interestingly, several proteins, mainly lower than 30 kDa molecular weight, were uniquely expressed in normal culture conditions. In contrast, several high molecular weight proteins (>55 kDa) were induced by acidic and low oxygen culture conditions. These findings not only provide new insights of association between morphological change and the virulence, but may also be useful in the design of immunological diagnosis and vaccines for M. abscessus infection.
Animals ; Electrophoresis ; Humans ; Hydrogen-Ion Concentration ; Immunologic Tests ; Macrophages ; Mice ; Molecular Weight ; Mycobacterium ; Oxygen ; Proteins ; Sprains and Strains ; Vaccines

BACKGROUND: In spite of the improvement in the quality of artificial heart valves and surgical techniques, the incidence of the complications following valve replacement is still high. We reviewed the clinical results of the valve replacements performed in Korean University Anam Hospital during the last 26 years. MATERIAL AND METHOD: The data of 571 patients who received valve replacement between December 1976 and December 2003 were reviewed. RESULT: There were 304 cases of MVR which was the most common procedure performed. There were 122 cases of AVR, and 111 cases of AVR with MVR. Among the 47 patients who received redo operation 38 cases were redo cases including 31 cases of MVR. 32.5% of the patients who had tissue valve replacement had second valve replacement with 10.2+/-3.9 years interval. 24.3% (139/571) of the patients developed valve related complications and cerebral infarction was the highest in frequency. Atrial fibrillation was related with increased complication rates and the mechanical valve replaced group had higher hemorrhagic complication rate than tissue valve replaced group. The operative mortality was 3.68% and the most common cause of the failure was low output syndrome. The operative mortality was higher in the patient group who had valve replacement before the year 1990. The patient group who had mechanical valve replacement had higher operative mortality rate than the tissue valve group. The 5-year survival rate was 92.2% and 10 year survival rate was 85.7%. CONCLUSION: The operative mortality of valve replacement has been improved. The mechnical valve replaced patients had higher hemorrhagic complication rate than the tissue valve replaced patients and more tissue valve replaced patients received redo valve replacement.
Atrial Fibrillation ; Cerebral Infarction ; Heart Valve Diseases ; Heart Valves* ; Heart* ; Heart, Artificial ; Humans ; Incidence ; Mortality ; Survival Rate