Recipient iNOS but Not eNOS Deficiency Reduces Luminal Narrowing in Tracheal Allografts

Chronic airway rejection is characterized by prolonged inflammation, epithelial damage, and eventual luminal obliterative bronchiolitis (OB). In cardiac allografts, the inducible nitric oxide synthase (iNOS) promotes acute rejection but paradoxically reduces neointimal formation, the hallmark of chronic rejection. The specific roles of NOS isoforms in modulating lymphocyte traffic and airway rejection are not known. Using a double lumen mouse tracheal transplant model, tracheal grafts from B10.A (allo) or C57BL/6J (iso) mice were transplanted into cyclosporine-treated wild-type (WT) iNOS−/− or endothelial NOS (eNOS)−/− recipients. OB was observed in WT tracheal allografts at 3 weeks (53 ± 2% luminal occlusion vs. 17 ± 1% for isografts, P < 0.05) with sites of obstructive lesion formation coinciding with areas of CD3+ CD8+ T cell–rich lymphocytic bronchitis. In contrast, allografts in iNOS−/− recipients exhibited reductions in local expression of proinflammatory chemokines and cytokines, graft T cell recruitment and apoptosis, and luminal obliteration (29 ± 2%, P < 0.05 vs. WT allografts). Recipient eNOS deficiency, however, suppressed neither chemokine expression, lymphocyte infiltration, nor airway occlusion (54 ± 2%). These data demonstrate that iNOS exacerbates luminal obliteration of airway allografts in contrast with the known suppression by iNOS of cardiac allograft vasculopathy. Because iNOS−/− airways transplanted into WT allograft hosts are not protected from rejection, these data suggest that iNOS expressed by graft-infiltrating leukocytes exerts the dominant influence on airway rejection

Successful thoracoscopic lobectomy for lung cancer in a patient with anatomic variation of the left inferior pulmonary vein

We present a case of primary lung cancer with a rare distribution pattern of left inferior pulmonary vein (PV), encountered in the thoracoscopic left lower lobectomy. Thoracoscopic observation revealed 2 trunks of inferior PV (ventral and dorsal branch) at the stem level. The ventral trunk consisted of a branch of vein (V(5)) from the lingular segment and venous ramifications (V(8)a, V(9) and V(10)a) from the basal segment. On the other hand, a branch of vein (V(6)) from the superior segment in the lower lobe and other veins (V(8)b and V(10)b + c) from the basal segment emptied together into the dorsal trunk. We successfully carried out a thoracoscopic left lower lobectomy without excision of the aberrant vein (V(5)). Retrospective review of the preoperative chest CT demonstrates the double trunk inferior PV and the aberrant lingular branch emptying with V(8)a into the ventral trunk. Knowledge of the branching variations of PV from preoperative evaluations leads to appropriate thoracoscopic procedures for lung cancer

A thoracoscopically resected case of mediastinal parathyroid cyst.

A 67-year-old male visited his physician because of a 2-month history of cough and sputum. An abnormal shadow at the left upper mediastinum on chest x-ray film was detected, and the patient was referred to our department for further examination. Chest x-ray film revealed a round shadow at the left upper posterior mediastinum. Computed tomography(CT)revealed a uniform iso density mass about 4 cm in diameter, with a well-defined border. After the intravenous contrast administration, a slight peripheral enhancement was seen around the mass. On magnetic resonance imaging, the mass was hypointense in T1-weighting and hyperintense in T2-weighting. The contrast pattern was the same as that observed in the CT scan. On sagittal and coronal sections, the mass was adjacent to the aortic arch. Although a benign tumor was mostly suspected based on imaging findings, a malignant tumor was also possible. Accordingly, we resected this mass with video-assisted thoracoscopy. Findings at operation were a cystic mass. The pathological findings were compatible with benign parathyroid cyst, which was suspected to be the cystic degeneration of a parathyroid adenoma.</p

Reciprocal regulation of airway rejection by the inducible gas-forming enzymes heme oxygenase and nitric oxide synthase

Obliterative bronchiolitis (OB) develops insidiously in nearly half of all lung transplant recipients. Although typically preceded by a CD8+ T cell–rich lymphocytic bronchitis, it remains unresponsive to conventional immunosuppression. Using an airflow permissive model to study the role of gases flowing over the transplanted airway, it is shown that prolonged inhalation of sublethal doses of carbon monoxide (CO), but not nitric oxide (NO), obliterate the appearance of the obstructive airway lesion. Induction of the enzyme responsible for the synthesis of CO, heme oxygenase (Hmox) 1, increased carboxyhemoglobin levels and suppressed lymphocytic bronchitis and airway luminal occlusion after transplantation. In contrast, zinc protoporphyrin IX, a competitive inhibitor of Hmox, increased airway luminal occlusion. Compared with wild-type allografts, expression of inducible NO synthase (iNOS), which promotes the influx of cytoeffector leukocytes and airway graft rejection, was strikingly reduced by either enhanced expression of Hmox-1 or exogenous CO. Hmox-1/CO decreased nuclear factor (NF)-κB binding activity to the iNOS promoter region and iNOS expression. Inhibition of soluble guanylate cyclase did not interfere with the ability of CO to suppress OB, implicating a cyclic guanosine 3′,5′-monophosphate–independent mechanism through which CO suppresses NF-κB, iNOS transcription, and OB. Prolonged CO inhalation represents a new immunosuppresive strategy to prevent OB

Computerized Tomography of Two Patients with Morning Glory Syndrome

Morning glory syndrome (MGS), an uncommon optic disc anomaly, is characterized by a funnel-shaped, excavated optic disc surrounded by chorioretinal pigmentary disturbance. Generally, it is an isolated ocular abnormality. The authors describe two patients in whom MGS developed in association with brain abnormalities. In both cases, there was enlargement of the optic nerve that showed increased radiodensity similar to that of sclera and cavum vergae in the brain cavity present in computerized tomography (CT). To our knowledge, the coexistence of MGS, cavum vergae and an enlarged retrobulbar optic nerve showing increased radiodensity have not been previously reported. The findings suggest that MGS may be based on a developmental anomaly involving the brain, and the enlarged optic nerve may be associated with sclera because of the isodensity in CT