Increasing Incidence of Nontuberculous Mycobacteria, Taiwan, 2000–2008

To assess the species distribution and epidemiologic trends of nontuberculous mycobacteria, we examined isolates from patients in Taiwan. During 2000–2008, the proportion increased significantly from 32.3% to 49.8%. Associated disease incidence increased from 2.7 to 10.2 cases per 100,000 patients. Mycobacterium avium complex and M. abscessus were most frequently isolated

Diagnosis of Tuberculosis by an Enzyme-Linked Immunospot Assay for Interferon-γ

*National Taiwan University Hospital, Taipei, Taiwan

Performance Assessment of the DR. MTBC Screen Assay and the BD ProbeTec ET System for Direct Detection of Mycobacterium tuberculosis in Respiratory Specimens

The performance of the DR. MTBC PCR-based assay and the BD ProbeTec ET Mycobacterium tuberculosis Complex Direct Detection (DTB) assay for the direct detection of Mycobacterium tuberculosis was evaluated using 1,066 consecutive clinical respiratory samples collected from 494 patients who did not have old cases of pulmonary tuberculosis and were not receiving antituberculosis treatment at National Taiwan University Hospital from January to February 2005. The results of both assays were compared to the “gold standard” of combined culture results and clinical diagnosis. The overall sensitivity and specificity of the DR. MTBC Screen assay were 56.6% and 98.9%, respectively, and of the DTB assay were 63.2% and 98.4%, respectively. The positive and negative predictive values for the DR. MTBC Screen assay were 84.5% and 95.4%, respectively, and for the DTB assay were 81.7% and 96.0%, respectively. The DR. MTBC Screen assay produced 11 false-positive results for 11 patients, including three samples yielding non-M. tuberculosis mycobacteria (one each for M. abscessus, a mixture of M. abscessus and M. chelonae, and unidentified non-tuberculosis mycobacteria). The DTB assay produced 15 false-positive results for 13 patients, including five samples from four patients yielding non-tuberculosis mycobacteria (two for M. abscessus, one for a mixture of M. abscessus and M. chelonae, and two for unidentified non-tuberculosis mycobacteria). This study demonstrated that the DR. MTBC Screen assay has a similar diagnostic value but fewer false-positive results than the DTB assay for respiratory specimens

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells

Regulation of the homeostatic concentrations of specific sets of transcription factors is essential for correct programming of cell proliferation and differentiation. We have characterized the signal transduction pathways regulating the catabolisis of p45/NF-E2, a bZIP factor activating the erythroid and megakaryocytic gene transcription. Through use of different approaches including nano-scale proteomics, we show that activated-JNK, or Phospho-JNK (P-JNK), physically interacts with p45/NF-E2 and phosphorylates its Ser157 residue. This reaction leads to the poly-ubiquitination of p45/NF-E2 at one or more of six Lys residues, one of which being also a sumoylation site, and its degradation through the proteasome pathway. Significantly, this regulatory pathway of p45/NF-E2 by P-JNK exists only in uninduced murine erythroleukemia (MEL) cells but not in differentiated MEL cells in which JNK is inactivated on DMSO induction. Based on the above data and analysis of the chromatin-binding kinetics of p45/NF-E2 and the erythroid gene repressor Bach1 during the early phase of MEL differentiation, we suggest a model for the regulation of erythroid maturation. In the model, the posttranslational modifications and turnover of p45/NF-E2, as mediated by P-JNK, contribute to the control of its homeostatic concentration and consequently, its regulatory functions in the progression of erythroid differentiation and erythroid gene expression