Yoshihiko Kageyama

Apoptosis Is Involved in Acute Cardiac Allograft Rejection in Rats

BACKGROUND Allograft rejection remains a major obstacle to long-term survival in heart transplantation. Recent studies have demonstrated that apoptotic cell death may occur in acute allograft rejection. The purpose of this study was to determine whether apoptotic cell death is involved in rat cardiac allograft rejection through both the perforin/granzyme pathway and the Fas/Fas ligand (Fas-L) pathway. METHODS Groups of Lewis (RT1(1)) rats underwent heterotopic heart transplantation from disparate DA (RT1a) or syngeneic Lewis rats. The cardiac grafts were harvested 1, 3, or 5 days after transplantation and analyzed for apoptotic cell death using DNA nick-end labeling, immunocytochemistry, and electron microscopy. In addition, the expression of granzyme B, perforin, Fas, and Fas-L messenger RNA were analyzed by reverse transcriptase-polymerase chain reaction. RESULTS Apoptotic cell death of cardiac myocytes was prominent in allografts on day 5 after transplantation. Fas gene transcripts were constitutively expressed in both syngeneic and allogeneic grafts, whereas expression of Fas-L was only upregulated in allografts with ongoing rejection. Granzyme B and perforin gene expression were also upregulated in allografts with ongoing rejection. CONCLUSIONS These results suggest that myocyte apoptosis through both the perforin-granzyme pathway and the Fas-Fas-L pathway may be involved in cardiac allograft rejection in rats.

Pericardial closure using fascia lata in patients undergoing pneumonectomy with pericardiectomy

In patients undergoing pneumonectomy with concomitant pericardiectomy, patch closure of the defect in the pericardium is required to prevent postoperative cardiac herniation. We used harvested autologous fascia lata as a pericardial patch in such operations on 6 patients with progressive lung cancer after induction chemoradiotherapy.

Response of Soft Tissue Against Hydroxyapatite Coated on Polymers

ABSTRACT The reaction of soft tissue against experimentally implanted polyethersulfone (PES) coated with hydroxyapatite (HA) was examined. PES, silicon-coated PES, and HA-coated PES were implanted subcutaneously in the abdomen of rats. Tissue reaction was examined weekly after implantation. The surrounding tissue firmly adhered to the HA-coated PES, and showed no sign of strong inflammatory reaction. Proliferations of fibroblasts were observed in contact with the surface of the HA-coated PES. Because of its good histocompatibility and the adhesiveness to soft tissues, this HA-coating technique may be very useful in the production of biomaterials.

Utilization of the Walking Oximetry Test to Allow Safe Ambulation After Pulmonary Resection

Abstract Supplemental oxygen therapy after pulmonary resection can generally be tapered according to arterial blood gases at rest or pulse oximetry (SpO2). However, detecting exercise-induced oxygen desaturation can be difficult. We developed the walking oximetry test (WOT) so that thoracotomy patients could be rehabilitated without the risk of undetected ambulatory hypoxemia. The subjects were 58 patients who had undergone pulmonary resection and could walk at the bedside, with oxygen at 3 l/min via a nasal cannula. Patients with a value of more than 100 torr were allowed to walk with assistance for 6 min in the corridor. The oxygen flow rate was kept at 3 l/min and the walking pace was less than 50 m/min. SpO2 was determined using a wristwatch pulse oximeter. The test was stopped if the SpO2 fell below 90% or there was a score of 5 or more on the Borg scale (range 1–10). Oxygen desaturation occurred in six patients (10%) during the WOT. These patients underwent ambulatory training with sufficient oxygen supplementation and were then tested again. Patients whose SpO2 values remained higher than 90% and who showed no more than 5% desaturation were permitted to walk in the corridor with oxygen at 3 l/min via a nasal cannula. All these patients had a Borg score of 4 or lower. The WOT is a reliable, nonvasive method for detecting exercise-induced oxygen desaturation during ambulation after pulmonary resection.

Structural Change of Hydroxyapatite Coated on Polymers Implanted in Soft Tissue

ABSTRACT Structural changes of two types of hydroxyapatite (HA) which were coated on polymers and implanted in soft tissue were studied. In amorphous type of HA-coating, crystallization occurred rapidly and Ca/P ratio increased within 2~3 weeks. The surface of HA-coated layer became to fine granular crystallization. In highly crystalline type of HA-coating, only a little change was observed. These results suggest that it is possible to chose an ideal type of HA-coating for a specific clinical purpose.

Intrathoracic Suture Abscess After Lobectomy for Early Lung Cancer

Intrathoracic suture abscess may occur around sutures on the pleura or in the lung parenchyma, although it is rare to encounter such cases clinically. We report on a 68-year-old woman with an intrathoracic (extrapulmonary) suture abscess, which was discovered on a chest X-ray film one year after right-middle lobectomy for early lung cancer. The abscess was removed surgically, and the postoperative course was uneventful. Pathological examination showed that it was caused by braided polyester sutures.