Kazuyoshi Shimada

Reduction of recipient macrophages by gadolinium chloride prevents development of obliterative airway disease in a rat model of heterotopic tracheal transplantation.

Background. Recent studies have shown the possible role of growth factors and the involvement of macrophages as a source of them in the pathogenesis of bronchiolitis obliterans (BO) after lung transplantation. Objective. The authors intended to determine whether depletion of recipient macrophages by gadolinium chloride (GdCl3) resulted in decreased obliterative airway disease (OAD) in a rat model of heterotopic tracheal transplantation. Methods. A tracheal segment of donor rats (Brown Norway) was transplanted into a subcutaneous pouch of fully major histocompatibility complex-incompatible recipient rats (Lewis). Recipients were injected intravenously with 80 mg/kg of GdCl3·6H2O or saline on days 0, 7, and 14 posttransplant. Allografts were harvested on days 7, 14, 17, and 21 and the degree of OAD resulting from fibroproliferative tissue was pathologically scored on a scale of 0 to 4. A portion of allografts was submitted to reverse-transcriptase polymerase chain reaction analysis to examine mRNA expression for platelet-derived growth factor (PDGF), basic fibroblast growth factor, and transforming growth factor-&bgr;1. Results. Immunohistochemical studies confirmed reduction in the number of ED2+ macrophages in tracheal allografts by GdCl3 injection. GdCl3 treatment significantly decreased OAD of allografts, with the histologic score of 1.4±0.3 in the treated animals compared with 3.0±0.5 in the controls (mean±SE, P =0.02) at day 21 posttransplant, and this was accompanied by decreased PDGF-A and PDGF-B gene expression in the GdCl3 group at day 17 posttransplant. Conclusions. Macrophage reduction by GdCl3 resulted in significantly decreased OAD development and reduced PDGF mRNA expression in allografts. This suggests a potential effectiveness of therapies targeting recipient macrophages in preventing BO after lung transplantation.

Recurrent thymoma : radiological (CT and FDG-PET) and histological (WHO criteria) features

A 66-year-old man, who had undergone surgical resection of a primary noninvasive thymoma (type B1) in the right anterolateral mediastinum 6 years before, underwent follow-up computed tomography (CT) scanning. The CT scan revealed a few nodules located at the posterior portion of the right thoracic base and just behind the right upper anterior chest wall. Subsequent fluorodeoxyglucose positron emission tomography (FDG-PET) scans showed multiple foci with high [standard uptake value (SUV) 4.3] and low (SUV 2.6) FDG uptake in the right lower posterior area and right upper anterior area of the chest, respectively. The fusion image of the CT and FDG-PET scans demonstrated that the areas of the increased FDG uptake corresponded to those of the nodules on the CT scan. All of the nodules were successfully removed surgically, and the histological features of the nodules indicated that they were type B1 or types B1 plus B2. We regarded the nodule located just behind the right upper anterior chest wall as a type B1 thymoma, whereas those in the posterior area of the right thoracic base as combined thymomas of types B1 plus B2. Our limited experience suggests that the degree of FDG uptake is a reflection of the subtype according to the World Health Organization (WHO) criteria. Furthermore, we showed the role of FDG-PET in the accurate assessment of recurrent thymoma and its therapeutic strategy.

Chest wall abscess due to Mycobacterium bovis BCG after intravesical BCG therapy

ABSTRACT We report a case of chest wall abscess caused by Mycobacterium bovis BCG that arose as a complication 1 year after intravesical BCG instillation. We identified M. bovis BCG Tokyo 172 in the abscess by PCR-based typing of Mycobacterium tuberculosis complex and analysis of variable number of tandem repeats data.

Roentgenographically occult bronchogenic squamous cell carcinoma involving mediastinal lymph nodes after removal of initial lesion by the diagnostic examination

A 69-year-old male was suspected of having lung cancer by sputum cytology and diagnosed as roentgenographically occult squamous cell carcinoma (ROSCC) at the spur of left B(1+2)/B(3). However, after the first bronchoscopy, no suspicious lesion was detected by any examinations. Therefore, we considered that cancer cells had been removed completely by the initial examination, and the patient was followed up by sputum cytology, chest roentgenogram, and bronchoscopy. Sixteen months later from the initial examination, bronchoscopy was performed for follow-up. The bronchoscopic findings showed the elevation of the surface of left B(1+2) a+b, but the cytologic specimen by brushing toward B(1+2) a+b showed negative findings. However, the lesion had developed to polypoid-shaped tumor and obstructed B(1+2) a+b after the next 6 months. The tumor was diagnosed as squamous cell carcinoma, and hilar and mediastinal nodal involvement was suspected on chest computed tomography. The standard thoracotomy was performed and the pathological results showed positive for nodal involvement on hilus and mediastinum. The tumor is considered to arise from the residual cancer cells of initially detected ROSCC. In conclusion, although some ROSCCs regress by the diagnostic examinations, it is important to detect the recurrence of residual cancer cells as early as possible by intensive follow-up.