K Nakamura

Expression of Cyclooxygenase-1 and -2 in Human Breast Cancer

AbstractPurpose. We investigated the expression of cyclooxygenase (Cox-1 and Cox-2) in mammary tissues from patients with breast cancer. Methods. We used reverse transcriptase–polymerase chain reaction (RT-PCR) and immunohistochemistry. Results. The cancer cells showed very weak expression of Cox-1, but strong expression of immunoreactive Cox-2. In contrast, immunoreactive Cox-2 was very weak in all of the benign mammary tumors examined, including fibroadenoma (FA) and mastopathy (MP). Immunoreactive Cox-1 was also very weak in these benign tumors. The extent and intensity of immunoreactive Cox-2 polypeptides was significantly greater in the cancer cells than in the FA cells or MP cells. RT-PCR analysis showed enhanced expression of Cox-2, but not Cox-1 in breast cancer tissue, and faint expression of Cox-2 in benign tissue. Conclusions. These results demonstrated that human breast cancer cells generated Cox-2, indicating that Cox-2 might play an important role in the proliferation of breast cancer cells.

EXPRESSION OF TISSUE FACTOR IN HEPATIC ISCHEMIC- REPERFUSION INJURY OF THE RAT

BACKGROUND Tissue factor (TF) is a membranous protein normally present on the surface of the fibroblasts and smooth muscle cells of vessels. TF is an initiation factor for blood coagulation, and its expression is induced on macrophages and endothelial cells during the inflammatory or immune response. We studied the significance of TF expression in warm ischemic-reperfusion injury of the liver using a rat model. METHODS Following laparotomy of Lewis rats, the branches of the hepatic artery and portal vein leading to the median, left, and caudate lobes of the liver were clamped for 2 hr. The liver was reperfused after 120 min of ischemia. Rats were killed at 0, 1, 3, 5, 8, and 12 hr after reperfusion, and liver tissues were harvested. TF activity was measured by the chromophilic substrate S-2222. TF expression was studied by immunohistochemical staining with the monoclonal antibody HTF-K108. RESULTS TF activity in the blood showed a peak at 3 hr after reperfusion (8.9+/-0.5 U/L), then decreased and returned to the normal level by 12 hr (0.9+/-0.3 U/L). TF activity in ischemic liver tissue increased gradually over 12 hr after reperfusion (1223+/-275 U/g dry weight before ischemia and 2545+/-284 U/g weight at 12 hr after reperfusion). Histologically spotty necroses were observed in the liver tissue 5 hr after reperfusion. The necrotic area extended and encompassed almost all of the ischemic liver by 12 hr after reperfusion. Histochemically, TF staining was negative on the hepatocytes and slightly positive on sinusoid cells of the normal liver. On the other hand, TF was strongly stained, especially on the hypertrophic monocytic cells accumulating at the site of the necrosis, but staining was not evident on the necrotic hepatocytes. A slight degree of TF staining was observed on the alveolar epithelium of the lung, irrespective of liver ischemia and reperfusion. CONCLUSION These results demonstrate that TF plays an important role in the development of the hepatic ischemic-reperfusion injury, and the subsequent microcirculatory incompetence might cause the formation of microthrombus and the development of necrosis.

The Effect Of Tissue Factor Pathway Inhibitor On Hepatic Ischemic Reperfusion Injury Of The Rat

BACKGROUND Tissue factor (TF) is an initiation factor for blood coagulation, and its expression is induced on macrophages and endothelial cells during the inflammatory or immune responses. In a previous study, we reported the significance of TF expression in hepatic ischemic reperfusion injury using a rat model. Recently, tissue factor pathway inhibitor (TFPI) has been discovered, and the effect of TFPI has been assessed in vivo. In this study, therefore, we studied the effect of TFPI on hepatic ischemic reperfusion injury of the rat. METHODS After laparotomy of Lewis rats, the branches of the hepatic artery and portal vein leading to the median, left, and caudate lobes of the liver were clamped. The liver was reperfused after 120 or 180 min of ischemia. Simultaneously, recombinant human TFPI (4 mg/kg) was injected via a superiomesenteric vein. Rats were sacrificed at 5, 12, and 24 hr after reperfusion, and liver tissues were harvested. TF expression was studied by immunohistochemical staining with the monoclonal antibody (HTF-K108). RESULTS Survival rates over a 5-day period were examined after the ischemic time of 120 and 180 min. Seven of 10 rats in the 120-min ischemia group (n=10), and only 1 (10%) rat of 10 in the 180-min ischemia group (n=10) survived. However, by the treatment with TFPI, all of the rats in the 120-min ischemia group (n=10), and six rats in the 180-min ischemia group (n=10) survived (P<0.05). The serum concentrations of alanine aminotransferase (ALT) and thrombin-antithrombin complex (TAT) before ischemia were 30.0+/-2.3 IU/L and 4.7+/-1.4 ng/ml, respectively (n=5). These levels showed a peak at 3-5 hr after reperfusion (ALT: 13909+/-1900 IU/L, TAT: 30.4+/-7.0 ng/ml) (P<0.01). However, both peak levels were decreased by the treatment with TFPI (ALT: 6017+/-1290 IU/L, TAT: 5.4+/-2.1 ng/ml) (P<0.01). Although TF was strongly stained on endothelial cells and Kupffer cells accumulating to the site of the necrosis in the control group, the area of the necrosis and the grade of TF staining were significantly reduced in the TFPI-treated group. CONCLUSIONS These results indicated that TFPI strongly inhibited the injury of the ischemic reperfusion, and confirmed that TF played a pivotal role in the development of ischemic reperfusion injury.

Antisense oligonucleotide for tissue factor inhibits hepatic ischemic reperfusion injury

Tissue factor (TF) is an initiation factor for blood coagulation and its expression is induced on endothelial cells during inflammatory or immune responses. We designed an antisense oligodeoxynucleotide (AS-1/TF) for rat TF and studied its effect on hepatic ischemic reperfusion injury. AS-1/TF was delivered intravenously to Lewis rats. After 10 h, hepatic artery and portal vein were partially clamped. Livers were reperfused after 180 min and harvested. TF expression was studied using immunohistochemical staining. One of 10 rats survived in a 5-day survival rate and TF was strongly stained on endothelial cells in non-treatment group. However, by treatment with AS-1/TF, six of seven survived and TF staining was significantly reduced. Furthermore, we observed that fluorescein-labeled AS-1/TF was absorbed into endothelial cells. These results suggest that AS-1/TF can strongly suppress the expression of TF and thereby inhibit ischemic reperfusion injury to the rat liver.

Pulmonary Embolism in a Living-Related Kidney Transplantation Donor

Abstract.Living-related renal transplantation is the optimal therapy for patients with end-stage renal disease (ESRD). Normally, complications are rare in living-related donor nephrectomy. However, we experienced a case of pulmonary embolism (PE). The incidence of PE in living donor nephrectomy is rare, but the total incidence of PE in surgical operations has recently increased. The patient in the case reported here was diagnosed relatively early and recovered with appropriate treatment. It is very important for surgeons to realize that serious complications such as PE can develop in any case of living donor nephrectomy.

Clinicopathological evaluation of renal allografts of four patients by 20‐year protocol biopsies

Abstract:  Twenty‐year protocol biopsies were performed in four cases of renal transplant recipients with grafts that had survived 20 years or more. All four recipients received transplants from their parents, and never had episodes of acute rejection. They were maintained with the conventional immunosuppressive protocol including azathioprine, mizoribine, and prednisolone. Three of them had past history of malignant diseases such as breast cancer and tongue cancer. In spite of fair graft function, the microscopic findings of 20‐year protocol biopsy showed various degrees of histological damage; e.g. obsolescence of the glomeruli, glomerulosclerosis, arteriole wall thickening, interstitial fibrosis and tubular atrophy. Although two of the four grafts were functioning with low serum creatinine levels (1.3–1.4 mg dL−1) at 24 years and 26 years following transplantation, respectively, the function of the other two grafts had decreased more than 20 years after transplantation. In the two grafts with decreased function, glomerulosclerosis and arteriole wall thickening tended to be more severe (Banff classification of chronic allograft nephropathy [CAN] grade II and III) at the 20‐year protocol biopsy compared with the two well‐functioning grafts (CAN grade I and II). We conclude that the protocol biopsies even at 20 years can contribute to predict the fate of renal allografts.