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M Negita

Publications and source records attributed to M Negita.

At least 19 recordsLinked to original sources
PubMed2001

[A case of renal oncocytoma with synchronous contralateral renal cell carcinoma].

A case of bilateral, synchronous renal cell carcinoma and oncocytoma is reported. The patient was a 70-year-old woman. Computed tomographic scan revealed bilateral low density masses, which had a diameter of approximately 4 cm (right kidney), and 2.5 cm (left kidney). We suspected bilateral renal cell carcinomas, and performed, right nephrectomy and left enucleation of the tumor. Pathological diagnosis was right renal cell carcinoma and left oncocytoma. To our knowledge only 5 previous cases of renal cell carcinoma associated with oncocytoma have been reported in Japan. Two cases were metachronous and three cases were unilateral and synchronous. This is the first reported case of bilateral, synchronous renal cell carcinoma and oncocytoma.

Adenoma, Oxyphilic↗
PubMed1998

[Bellini duct carcinoma of the kidney: a case report].

A case of Bellini duct carcinoma is reported. A 71-year-old woman visited our hospital with a chief complaint of lower abdominal pain. Computerized tomography, ultrasonography showed a mass lesion measuring about 5 cm in the right kidney. Angiography showed an avascular mass lesion in the right kidney. Right radical nephrectomy was performed under the diagnosis of renal cell carcinoma. Histological examinations showed Bellini duct carcinoma of the papillary type. We performed M-VAC (methotrexate, vinblastine, doxorubicin, icisplatin) therapy as is used for transitional cell carcinoma. She is alive with no evidence of disease 5 months after her surgical treatment. To our knowledge, only 32 cases of Bellini duct carcinoma have been reported in the Japanese literature.

Aged↗
PubMed1997

Measurement of portal venous flow velocity with an implantable miniature Doppler probe in pig liver transplantation.

Portal venous flow (PVF) was serially monitored after pig liver transplantation (LTX) with the use of an implantable, miniature Doppler probe developed in our laboratory. Throughout the study period, the mean PVF in pigs that underwent LTX was significantly greater than that in pigs that were sham operated. For three animals with early graft failure secondary to primary nonfunction and for six that survived longer than 7 days, the mean PVF on postoperative day (POD) 1 was 18.7 +/- 3.8 cm/s and 41.7 +/- 11.2 cm/s, respectively (P < 0.05). For animals with acute cellular rejection (ACR), the mean PVF was 61.3 +/- 9.9 cm/s on POD 7 and 54.3 +/- 6.38 cm/s on POD 14. These values were significantly higher than those for animals without ACR (P < 0.05). Moreover, the increase in PVF correlated well with the degree of ACR. The actual PVF volume was measured by ex vivo perfusion, which showed a clear correlation with the PVF velocity obtained with the implanted, miniature Doppler probe. We feel that the liver graft requires increased PVF volume after transplantation to facilitate functional recovery from damage to hepatocytes due to preservation-reperfusion injury, and that ACR is also associated with an increased PVF. We conclude that monitoring the PVF in the early postoperative period after LTX is useful in the evaluation of graft function, particularly for predicting primary nonfunction and severity of ACR.

Animals↗
PubMed1997

Fas antigen expression of hepatocytes and its modification by immunosuppressants.

Active cell death induced by ligation of the Fas antigen (Fas-Ag) with its antibody, Fas ligand (Fas-L), has been known to play a major role in cell killing via apoptosis by cytotoxic T lymphocytes (CTL). Thus, in liver transplantation, Fas-Ag expression of hepatocytes and its modification by immunosuppressive agents such as FK 506 or CsA can theoretically influence allograft survival. Mouse hepatocytes (BALB/c) were isolated and cultured with or without FK 506 or CsA, and Fas-Ag expression was determined by flow cytometry. Fas-Ag expression in the control was 17.2 +/- 2.5% after 24 hr of culture. When FK 506 or CsA was added, Fas-Ag expression with FK 506 at a concentration of 0.01-0.1 microg/ml was significantly lower than that with CsA (P < 0.05). When the cells were incubated with apoptosis-inducing anti-Fas-Ag monoclonal antibody, agarose gel electrophoresis of the control cells yielded a typical pattern of DNA fragmentations. The cells with FK 506 at 0.01 microg/ml yielded the least DNA fragmentation. These findings suggested that in the in vivo setting, the hepatocytes of the allograft would have a lower chance of being attacked by CTL in the host treated with FK 506.

Animals↗
PubMed1997

Living related liver transplantation in Oklahoma.

Living related liver transplantation (LRLT) presents several advantages as compared to cadaveric liver transplantation, and it has become an increasingly popular option for children with end-stage liver diseases. Since 1995, five LRLT procedures have been performed at the authors' facility. Recipients were three boys and two girls, whose mean age was 2.6 years. Recipients' primary diagnoses were primary hyperoxaluria (PH) (n = 3), Alagille's syndrome (n = 1), and Byler's disease (n = 1). Left lateral segments harvested from their parents were used as the liver grafts on all patients. The donors included three mothers and two fathers, with a mean age of 29 years. Tacrolimus with steroids was used as immunosuppressive therapy. In all cases (mean follow-up time of 11 months), graft function was excellent and four children are doing very well. One boy died of post-transplant lymphoproliferative disorder (PTLD) 7 months after LRLT. All donors are doing very well with no postoperative complications. The authors believe that LRLT is a safe procedure for both the donor and the recipient, and provides, in children, an excellent alternative to cadaveric liver transplantation.

Adult↗
PubMed1996

Human superoxide dismutase cDNA transfection and its in vitro effect on cold preservation.

In order to elucidate the role of superoxide dismutase (SOD on ischemia-reperfusion injury, bovine and porcine aortic endothelial cells were transfected with retroviral vector LSODRNL containing human Cu,Zn-SOD cDNA and their SOD activities were evaluated by measuring superoxide scavenging capability. Successful augmentation of Cu,Zn-SOD up to 2.7-fold in bovine and 1.9-fold in porcine cells was obtained. After 24 h cold preservation followed by 4 h rewarming, cell viability compared with that of pre-preservation was significantly increased in both types of cells (P < 0.01). Moreover, after exposure to superoxide, viability of the porcine cells with high SOD activity was significantly improved compared to control cells. We consider that transfection of human Cu,Zn-SOD cDNA to arterial endothelial cells is useful for preventing from cold preservation-rewarming or ischemia-reperfusion injury.

Animals↗
PubMed1996

Beneficial effect of donor pretreatment with thromboxane A2 synthase inhibitor on the graft survival in pig liver transplantation.

With a known evidence that thromboxane A2 (TxA2) is elevated in the perfusate of the liver transplant (LTx) recipient, TxA2 is likely to play a role in the pathogenesis of preservation reperfusion injury. In this study, effectiveness of donor pretreatment with TxA2 synthase inhibitor, sodium ozagrel (SO), in the prevention of primary nonfunction (PNF) was investigated. LTx was performed for eight pigs which received the grafts treated with SO during harvest surgery (treatment group). Eight other animals were the control group. All of the animals in the treatment group survived longer than 7 days, whereas 37.5% (three of eight) of the control group died from PNF within 3 days postoperative. Significantly lower serum LDH levels were noted in the treatment group than control. Serum thromboxane B2 (TxB2) and 6-keto-PGF1 alpha were both elevated in the control group. However, a significant decrease in TxB2 was noted in the treatment group after reperfusion of the liver graft. Polymorphonuclear leukocyte (PMN) infiltration in the graft after reperfusion was significantly greater in the control group than in the treatment group. Hepatocyte microsteatosis was prominent in the control group after reperfusion. Donor pretreatment with SO was effective in the prevention of PNF after LTx. The beneficial effects of this drug are improvement in microcirculation allowing better perfusion of cold preservative and the blocking effect of platelet-PMN-endothelial interaction which is thought to be a primary etiology in reperfusion injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Liberation of vasoactive substances and its prevention with thromboxane A2 synthase inhibitor in pig liver transplantation.

There are multiple causes of liver graft nonfunction in the early post-transplant period. Since a severe microcirculatory disturbance based on ischemia-reperfusion liver injury is considered to be the main underlying pathophysiology, it is suspected that various vasoactive substances are liberated after reperfusion of the graft. In order to investigate this matter, we conducted an experimental study with pig liver allotransplantation. Two groups of animals received donor grafts with or without thromboxane synthase inhibitor (sodium ozagrel), 1.25 mg/ kg body weight intravenously, given at the time of liver harvesting. All of the recipient animals in the treatment group (n = 10) survived longer than 7 days whereas three of ten animals in the control group died within 7 days. Serum lactate dehydrogenase (LDH) in the recipient serum at 1 h after reperfusion was significantly lower in the treatment group (915.1 +/- 167.3 U/l) than in the control group (1264.4 +/- 134.7 U/l). Serum thromboxane B2 (2261.7 +/- 1055.7 pg/ml) and endothelin-1 (6.3 +/- 2.2 pg/ml) after reperfusion in the treatment group were significantly lower than those in the control group (4220.0 +/- 1711.0 pg/ml and 11.2 +/- 3.1 pg/ml, respectively). Although serum angiotensin II after reperfusion tended to be lower in the treatment group than in the controls serum renin activity was less than 3 ng/ml in both groups of animals. There were no differences in the plasma endotoxin levels between the two groups. We conclude that the administration of sodium ozagrel to the donor animals provided better graft function in recipients than no such treatment. We speculate that the inhibition of thromboxane A2 production suppresses the liberation of other vasoconstrictive substances, preventing microcirculatory disturbance and, thereby, contributing to improved graft function after liver transplantation.

Angiotensin II↗