A right paratracheal air cyst caused by tracheal diverticula.

A 65-year-old woman presented with pain in her throat and neck. Thin-section computed tomography (CT) revealed an air-filled lesion at the right paratracheal region and two narrow connections to the trachea. Flexible bronchoscopy showed four diverticula 4-5 cm below the vocal cords in the right lateral part of the trachea. Consistent with the CT findings, two of the diverticula were deep. A radiological barium swallow study and an esopagogastroduodenal endoscopic examination revealed no abnormalities. We therefore believe that her right paratracheal air cyst is an extension of a tracheal diverticulum. Right-sided paratracheal air cysts at the level of the thoracic inlet are a common finding on CT and should not be confused with pneumomediastinum in order to avoid unnecessary examinations or treatments.

[A case of lung adenocarcinoma with gradual enlargement of thin-walled cavity causing pneumothorax].

A 71-year-old man presented with a thin-walled cavity in his left lung in November 2006. A previous chest CT in 2003 showed a small thin-walled cavity in his left lingula. Although no obvious change was observed in 2004, the cavity increased its size from 11mm to 14mm in diameter and the wall became thicker in June 2006. On the first visit to our hospital in November 2006, the diameter of the cavity was 30mm and some part of the wall was thinner than on the previous CT. The patient developed pneumothorax one month later and underwent segmentectomy of the left lingula after unsuccessful thoracic drainage. Poorly differentiated adenocarcinoma was identified in both the pleura and the inner wall around the cavity. Lung adenocarcinoma with gradual enlargement of a thin-walled cavity causing pneumothorax has never been reported before. We report here the natural course of lung adenocarcinoma with a thin-walled cavity.

[Case of pneumothorax associated with pulmonary Mycobacterium fortuitum infection].

A 39-year-old man with dyspnea was revealed to have severe pneumothorax and received partial resection of the left upper lobe after unsuccessful drainage. Necrotizing epitheloid granuloma was found in the resected lung and Mycobacterium fortuitum was detected from the lesion. Chemotherapy with levofloxacin and clarithromycin was started one year after surgery because of the newly found nodular shadow near the lesion. The case experienced pyothorax due to pulmonary tuberculosis three years before and Mycobacterium avium pleuritis one year before this episode. Three-time mycobacterial pleural infection in three years seems to be uncommon. Furthermore this is the first report of pneumothorax associated with pulmonary Mycobacterium fortuitum infection.

Facilitated angiogenesis induced by heme oxygenase-1 gene transfer in a rat model of hindlimb ischemia.

Heme oxygenase-1 (HO-1) is an inducible form of heme oxygenase that catabolizes heme to carbon monoxide, biliverdin, and ferrous iron. We have investigated whether HO-1 can induce angiogenic effects in vivo. Rats were subjected to a bolus injection of either wild type adenovirus (ad-wt) or adenovirus encoding HO-1 (ad-HO-1) through the right femoral artery, which was then removed immediately. HO-1 gene transfer resulted in about a sixfold increase in HO-1 protein levels as compared to the non-treated animals. The increase in both blood flow and capillary density was significantly greater in the ischemic hindlimbs that had been injected with ad-HO-1 than in those injected with ad-wt. These angiogenic effects of ad-HO-1 infection could be completely abolished by treating the animals with the HO inhibitor, zinc protoporphyrin, indicating that they were specifically due to the expression of HO-1. Thus, HO-1 gene transfer improves the blood flow in ischemic hindlimb, at least in part, via angiogenesis facilitated by the induction of this molecule.