Naotake Shimoda

Increased serum levels of vascular endothelial growth factor in patients with renal cell carcinoma

Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. One such factor, vascular endothelial growth factor (VEGF), is considered to exert a potent angiogenic activity, as indicated by immunohistochemical and molecular evidence. In this study we investigated the serum VEGF level (s‐VEGF) in patients with renal cell carcinoma (RCC). s‐VEGF in peripheral blood samples was analyzed in 40 RCC patients and 40 patients without cancer (controls) using a sandwich enzyme‐linked immunoassay. In 20 RCC patients, serum samples were obtained separately from the bilateral renal veins. s‐VEGF was also measured before, 4 and 8 weeks after nephrectomy in 11 patients. There were significant differences in s‐VEGF between the RCC patients and the controls (207.3 ± 32.9 vs. 71.5 ± 9.1 pg/ml, mean ± SE) (P < 0.005), between the tumor‐bearing renal veins and the contralateral ones (P < 0.01), between the pre‐ and post‐nephrectomy situations (P < 0.01) and among the various parameters of tumor status such as tumor extent (P < 0.001) and existence of metastasis (P < 0.001). s‐VEGF significantly correlated with the tumor volume obtained by a three‐dimensional measurement (r= 0.802, P < 0.0001). The sensitivity and specificity of s‐VEGF at the cut‐off level of 100 pg/ml, as determined by the receiver‐operating‐characteristics curve, were 80.0% and 72.5%, respectively. The results indicate that tumor tissue of RCC liberates VEGF into the systemic blood flow and that s‐VEGF is a possible marker for RCC.

Chronopharmacokinetics of Tacrolimus in Kidney Transplant Recipients: Occurrence of Acute Rejection

The circadian variation of clinical pharmacokinetics of tacrolimus was studied using 16 adult renal transplant recipients 1 month after the operation. The recipients were administered tacrolimus twice a day (9 a.m. and 9 p.m.), and whole‐blood samples were obtained just prior to and 1, 2, 3, 6, 9, and 12 hours after oral administration. Histological specimens of transplant kidney were collected by an allograft core biopsy on day 28 after the transplantation. There were no circadian changes in the area under the concentration‐time curve (AUC0–12) (214 ng•h/mL during daytime vs. 223 ng•h/mL during nighttime) resulting from morning and night doses. A slight delay in mean residence time (MRT0–12) and time to the peak concentration (tmax) was found after night doses, but there was no statistical significance. Three patients (18.8%) had a clinical acute rejection (AR) episode 4 to 6 weeks after transplantation, and AUC0–12 at nighttime was significantly lower (18.4% on average) in patients with AR in comparison to those without AR. There was no statistical significance in maximum concentration (Cmax) or morning/night trough levels between patients with and without AR. In regard to the correlation between tacrolimus concentrations in each sampling time and AUC0–12, the morning trough concentrations were less predictable for daytime AUC0–12 (r2 = 0.125), but there was a weak correlation to nighttime AUC0–12 (r2 = 0.424). Tacrolimus concentrations at 2, 3, and 6 hours after the morning dose (C2, C3, and C6) had a good correlation against daytime AUC. The results of this study indicate that the variance on the clinical pharmacokinetics of tacrolimus between daytime and nighttime in renal transplant patients is not significant, while the lower nighttime AUC corresponded to the occurrence of AR.

An Accessory Spleen Mimicking a Nonfunctional Adrenal Tumor: A Potential Pitfall in the Diagnosis of a Left Adrenal Tumor

We describe a case of accessory spleen mimicking a left adrenal tumor. A 66-year-old woman was referred to our hospital because of a suspected left adrenal mass detected by US. A laparoscopic adrenalectomy was performed, and examination of the surgical specimen revealed that the resected adrenal gland contained no tumorous lesion. A further investigation of the intraperitoneal space revealed an accessory spleen. This indicates that urologists should be aware of the possible existence of accessory spleens when left adrenal tumors are suspected on CT and MRI.

Chrono and clinical pharmacokinetic study of tacrolimus in continuous intravenous administration

Abstract Background: The circadian variation of clinical pharmacokinetics of tacrolimus in kidney transplant recipients receiving continuous intravenous administration has not been clarified. The aim of this study was to evaluate the circadian variation of this drug in continuous intravenous administration, with regard to the dosing scheme for conversion from intravenous to oral therapy.

A novel antireflux technique using an intussuscepted ileal segment.

A novel surgical technique of antireflux with an ileal conduit for urinary diversion is presented with our early results. The mid 8-cm portion of an isolated terminal ileum is intussuscepted. After skeletonization of the mesenterial vasculature, 3 rows of 4 mattress seromuscular silk sutures are placed on the ileum. By tying the sutures successively, the ileum is intussuscepted and the resultant nipple is secured simultaneously between its outer and inner layers. The outer nipple layer and the recipient ileal layer are further fixed as a whole by placing 3 rows of metal staples. The nipple base is secured by interrupted silk sutures and the mesenterial defect is closed. This technique was applied to 30 patients undergoing rectosigmoidal bladder procedure, a modified ileocecal rectal bladder, in which the antireflux conduit was interposed between the ureters and the rectosigmoidal pouch. Ureteral reflux was observed in none of the patients during a mean follow-up period of 29.9 months. Of the 60 renal units, 53 (88.3%) had normal pyelography and 7 (12.7%) showed mild hydronephrosis at 3–6 months postoperatively. This antireflux technique is simple and reliable, and can be applied to other urinary diversion/reconstruction surgeries, such as the continent reservoir, orthotopic neobladder, and/or bladder augmentation.

Rectosigmoidal bladder utilizing intussuscepted ileal segment: A surgical technique for urinary diversion and experiences in 30 patients

Background: We previously reported that the ileocecal rectal bladder consists of interposition of an intussuscepted ileocecal segment between the ureters and the rectum for those in whom the urethra is not available. Although the ileocecal rectal bladder has been well accepted by most patients, it requires an extensive preparation along the ascending colon. We present a modified operation technique (rectosigmoidal bladder) by using the ileal segment alone as an interposing antireflux component and by using the sigmoidal segment to augment the rectal capacity.

Successful renal transplantation in the right iliac fossa 2 years after serious deep venous thrombosis in a patient with systemic lupus erythematosus

Abstract  Deep venous thrombosis (DVT) possibly occurs in the perioperative period, and induces serious complications such as a pulmonary embolism. On the other hand, allograft renal vein thrombosis leads to a high incidence of graft loss. We experienced a case in which a serious DVT occurred prior to renal transplantation; however, a successful renal transplantation in the right iliac fossa was performed after 2 years of anticoagulant therapy. It is suggested that the external iliac vein even after suffering from DVT can be anastomosed to an allograft vein successfully, when enough blood flow or a lower venous pressure is confirmed. However, one should be aware of the risk factors and the adequate management of thrombosis in renal transplantation because of the serious complications of DVT and the poor prognosis of allograft vein thrombosis.