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Biomedical subjects

I Nakai

Publications and source records attributed to I Nakai.

At least 19 recordsLinked to original sources
PubMed1995

The role of pancreatic islets in experimental pancreatic carcinogenicity.

Our previous studies have suggested that the presence of intact islets is essential for the induction of pancreatic exocrine tumors in the Syrian hamster model. To validate this, we investigated the effect of the carcinogen, N-nitrosobis(2-oxo-propyl)amine (BOP) in hamsters, in which homologous isolated intact islets were transplanted into the submandibular gland (SMG). Freshly isolated pure islets from hamster donors were transplanted into the left SMG of 20 female host hamsters. Ten of these hamsters (group 1) received BOP (40 mg/kg) weekly for 3 weeks. Another 10 hamsters (group 2) were kept untreated. In groups 3 and 4 (10 hamsters each) the salt solution or isolated pancreatic ductal cells, respectively, was injected into the gland. In other groups (10 hamsters each) islets were transplanted into the peri-SMG connective tissue (group 5) or into the renal subcapsular space (group 6). Hamsters of group 1 (40 mg/kg, weekly for 3 weeks) as were group 7 hamsters, which served as BOP-treated controls. All BOP-treated hamsters developed pancreatic lesions. Similar hyperplastic and atypical ductal/ductular proliferation and in situ carcinoma were found in the SMG of many group 1 hamsters. No such lesions were found in the SMG, peri-SMG, or renal subcapsular space of the other groups. Islets appear to be involved in carcinogenicity of BOP. The mechanism is obscure.

Animals↗
PubMed1995

[Renal autotransplantation for dissecting aneurysm].

Out of twenty-five patients operated on for dissecting aneurysm in our institution since January 1991, four patients had autotransplantation of the kidney. The renal autotransplantation and the segmental replacement of the descending aorta with the prosthesis were done at the same time in three of them, and segmental replacement of the distal aortic arch was followed by autotransplantation because of the postoperative acute renal failure in the other one. Postoperative renal function of simultaneously operated patients was good whereas the patient who had been treated by two-staged operation needed hemodialysis for two weeks after the autotransplantation. Postoperative scintigraphy showed fully recovered function of the autotransplanted kidneys with enlargement. CT scan showed that the false lumen of the dissecting aorta was reduced in size with increased intraluminal clot formation. Renal autotransplantation with entry closure is easy and safe technique and assures successful operative results for the dissecting aneurysm, restoring impaired renal blood flow.

Acute Kidney Injury↗
PubMed1994

[De novo malignancy following renal transplantation].

The characteristics and incidence of de novo malignancy was analyzed in 376 renal transplant recipients transplanted between April 1970 and December 1992. Malignancies developed in 21 recipients of living related donor renal allografts. The total number of malignancies was 23, with 2 patients developing 2 malignancies. The mean age at the time of diagnosis was 42 years. The average interval from transplantation to the time of diagnosis was 129 months. Malignancy developed in 12 of 21 patients who survived 10 years with a functioning graft. Nine patients died of their malignancy. The risk of developing malignancy is increased following renal transplantation. Compared with sex- and age-matched Japanese control, the incidence is 6.1 times greater for male, 10.5 times greater for female, and 7.3 times greater overall. The risk was increased at all sites except the stomach. The risk rate of acquiring malignancies at 5-year intervals following transplantation was 6.5 times greater from 0 to 5 years, 10.0 times greater from 5 to 10 years, and 9.3 times greater from 10 to 15 years. These results suggest that annual medical examinations should be performed as part of the routine log-term follow-up of renal transplant recipients to detect malignancies in the early stage.

Adult↗
PubMed1993

En bloc kidney and whole pancreaticoduodenal transplantation with bladder drainage in the rat: microsurgical technique and outcome.

A microsurgical technique for en bloc kidney and whole pancreaticoduodenal transplantation with bladder drainage employing triple vascular anastomoses without the need for a vascular cuff is described. Nineteen combined isografts were performed using this technique in inbred male Lewis (RT1:I) rats with streptozotocin-induced diabetes. Six recipients died within 1 month from early complications (two from uremia, two from pancreatitis, one from bleeding, one from peritonitis); the other 13 survived more than 1 month after transplantation with both the pancreas and kidney grafts functioning. Four of the 13 rats died after 1 month (one from uremia secondary to an obstructed ureter, one from unexplained uremia, one from peritonitis after a biopsy, and one of unknown causes). The pancreas isografts of two animals were excised at 1 and 3 months to confirm dependence on the graft; both animals became hyperglycemic after graft pancreatectomy and had immediate declines of urine amylase activity to normal. One animal was sacrificed at 3 months to determine the insulin content of its native and transplanted pancreas; insulin was very low in the former and normal in the latter. The remaining rats survived with both grafts functioning for at least 6 months (normoglycemic, high urinary amylase levels, normal or near-normal plasma creatinine concentrations), before being sacrificed within the context of other experiments and for histological observations. Both the kidney and pancreas isografts were well preserved microscopically.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1993

[Renal autotransplantation and graft replacement for DeBakey IIIb dissecting aneurysm--a case report].

A successfully repaired case, a 53-years old man, who suffered DeBakey IIIb type dissecting aneurysm and renal dysfunction was reported. The right kidney, of which artery was originated from the false lumen, was autotransplanted to the right iliac system to improve the renal blood circulation. Then the descending aorta was segmentally replaced with the prosthesis under profound hypothermia, circulatory arrest and retrograde cerebral perfusion without cross-clamping the aortic arch. Three months later, aortography and catheterization study suggested that the reperfused left kidney resulted in renin-dependent hypertension. Kidney, therefore, was resected to improve blood pressure control. Patient recovered successfully, with no evidence of neurological complication.

Aortic Dissection↗