Hirofumi Tomori

Analysis Of Fas System In Pulmonary Injury Of Graft-versus-host Disease After Rat Intestinal Transplantation

The lung is one of the primary targets of acute graft-versus-host disease (GVHD), which is the principal complication that occurs after allogeneic intestinal transplantation. The purpose of this study is to investigate the involvement of Fas/Fas ligand system in pulmonary injury after rat semi-allogeneic intestinal transplantation. The lungs were serially harvested from LEW x BN F1(LBNF1) recipients of either LEW heterotopic intestinal allografts or LBNF1 isografts, on days 1, 3, 5, 9, and 13 posttransplant. In light microscopy, pulmonary injury became apparent on day 13 in the allogeneic combination, showing a thickening of the alveolar septa. The incidence of apoptosis, examined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) biotin nick end-labeling, was observed to increase steadily in the alveolar cells accompanied by a progression of GVHD. In an immunohistochemical study, Fas was constitutively expressed in the lung, although Fas ligand was expressed most extensively on day 9. The immunoreactivity of both Fas and Fas ligand were observed in alveolar cells, in addition to leukocytes. An analysis by reverse transcription polymerase chain reaction also revealed that the expression of Fas mRNA was constitutive without any significant change, although that of Fas ligand mRNA increased substantially and peaked on day 9, which was significant compared to the isogeneic combination. In conclusion, transcriptionally up-regulated Fas ligand and increased number of apoptosis suggests that the Fas system may play a role in the pathophysiology of GVHD-induced pulmonary injury.

Radiation-associated ischemic coloproctitis: report of two cases.

Radiation-associated ischemic coloproctitis is a rare clinical entity caused by vascular insufficiency to the rectosigmoid colon. It most commonly occurs after radiotherapy for gynecological cancer. We present herein the cases of two patients who developed radiation-associated coloproctitis with transmural necrosis and eventual perforation. Perforation of the rectosigmoid colon occurred 3.5 years after radiotherapy in case 1, a 46-year-old woman, and presented as a well-defined small area of transmural necrosis. Conversely, in case 2, a 55-year-old woman, it occurred 1.5 years after radiotherapy, and presented as segmental, diffuse transmural necrosis. The lesion in case 1 had been caused by intramural vascular obliteration due to marked fibrosis of the bowel wall, while that in case 2 had been caused by occlusion of the mesenteric artery with thrombosis. Both patients underwent Hartmann’s resection without rectal excision, and survived the perforative event.

In situ perfusion of the liver enhances the efficiency of retrovirus-mediated gene transfer to hepatocytes

To increase the efficiency of retrovirus-mediated gene transfer targeting an individual’s liver in vivo, the liver was perfused in situ with the retrovirus vector during hepatic cold ischemia. Four weeks prior to gene transfer, the spleen was transpositioned to the left subcutaneous position to develop a portosplenic shunt, which was performed in order to prevent intestinal congestion during hepatic ischemia. Traditional retrovirus vectors (1 × 105 CFU/ml) which encode genes for the Escherichia coli β-galactosidase (LacZ) were used in this study. Twenty-four hours after partial hepatectomy (70%), the remnant liver was surgically isolated, perfused with 1 ml of vector solution through the portal vein, and kept in contact with the vector for 30 min under cold ischemia (group 1). Hepatic ischemia could thus be performed without any intestinal congestion, due to the preestablished portosystemic shunt. In group 2, the liver was perfused with 1 ml of vector solution through the portal vein without in situ perfusion of the liver. Animals were sacrificed 1, 3, 7 and 28 days after gene transfer. In X-gal staining, the transferred LacZ was detected positive in 10–15% of the hepatocytes only in group 1, 3 days after gene transfer. Graft histology and a liver function test showed no difference between both groups 24 h after gene transfer. In conclusion, in situ perfusion of the liver greatly enhanced the efficacy of retrovirus-mediated gene transfer, targeting an individual’s liver in vivo.