Secondary spontaneous pneumothorax in a patient with resistant Mycobacterium abscessus infection and systemic sclerosis-associated interstitial lung disease: A case report.

Mycobacterium abscessus subsp. abscessus (MABA) is refractory and sometimes fatal especially in an immunocompromised patient. Also, MABA-associated pneumothorax is an extremely rare complication. We report a case of MABA pulmonary infection complicated pneumothorax treated successfully. A 69-year-old Japanese female with immunosuppressed systemic sclerosis-associated interstitial lung disease experienced left-sided secondary spontaneous pneumothorax. MABA was detected in the pleural effusion and blood culture. Microbial sensitivity test showed the MABA was sensitive to only amikacin, sitafloxacin, and clofazimine. Combination therapy with these antibiotics including azithromycin achieved remission within three weeks. In the treatment of MABA infection, compliance with microbial sensitivity test is crucial.

The Neo-X Does Not Form a Barr Body but Shows a Slightly Condensed Structure in the Okinawa Spiny Rat (Tokudaia muenninki).

X chromosome inactivation (XCI) is an essential mechanism for gene dosage compensation between male and female cells in mammals. The Okinawa spiny rat (Tokudaia muenninki) is a native rodent in Japan with XX/XY sex chromosomes, like most mammals; however, the X chromosome has acquired a neo-X region (Xp) by fusion with an autosome. We previously reported that dosage compensation has not yet evolved in the neo-X region; however, X-inactive-specific transcript (Xist) RNA (long non-coding RNA required for the initiation of XCI) is partially localized in the region. Here, we show that the neo-X region represents an early chromosomal state in the acquisition of XCI by analyses of heterochromatin and Barr body formation. We found no evidence for heterochromatin formation in the neo-X region by R-banding by acridine orange (RBA) assays and immunostaining of H3K27me3. Double-immunostaining of H3K27me3 and HP1, a component of the Barr body, revealed that the entire ancestral X chromosome region (Xq) showed a bipartite folded structure. By contrast, HP1 was not localized to the neo-X region. However, BAC-FISH revealed that the signals of genes on the neo-X region of the inactive X chromosome were concentrated in a narrow region. These findings indicated that although the neo-X region of the inactive X chromosome does not form a complete Barr body structure (e.g., it lacks HP1), it forms a slightly condensed structure. These findings combined with the previously reported partial binding of Xist RNA suggest that the neo-X region exhibits incomplete inactivation. This may represent an early chromosomal state in the acquisition of the XCI mechanism.