Takehiro Nishiki

Effect of Milrinone on Ischemia-Reperfusion Injury in the Rat Kidney

BACKGROUND Milrinone (MIL), a phosphodiesterase (PDE) 3 inhibitor, exhibits cardiotonic and angioectatic effects. Various PDE inhibitors have been shown to suppress inflammatory cytokines. In this study, we evaluated the angioectatic and anti-inflammatory cytokine effects of MIL on renal function after warm ischemia in a rat ischemia-reperfusion (I-R) injury model. MATERIALS AND METHODS MIL or control solution was perfused from the left renal artery to the right kidney, and the left kidney was excised. The right renal artery, vein, and ureter were clamped and then released after 50 minutes to produce warm ischemia. We evaluated control (n = 7), MIL (n = 7), and sham operation (n = 7) groups for serum creatinine, blood urea nitrogen (BUN), blood flow, expression of tumor necrosis factor (TNF)-α mRNA, apoptosis index, and histological evidence of acute tubular necrosis. RESULTS Serum creatinine and BUN concentrations peaked at 24 hours after reperfusion. MIL treatment significantly reduced serum creatinine (control group 1.27 ± 0.45 mg/dL vs MIL group 0.77 ± 0.19 mg/dL, P < .05; sham 0.35 ± 0.2 mg/dL) and BUN (control 67.6 ± 13.6 mg/dL vs MIL 51.0 ± 8.8 mg/dL, P < .05; sham 23.0 ± 4.2 mg/dL) levels at 24 hours. Thereafter, serum creatinine and BUN concentrations in the MIL group remained significantly lower compared with the control group for 120 hours (P < .05). MIL group exhibited significantly higher tissue blood flow, less acute tubular necrosis, lower expression of TNF-α mRNA in renal tissue, and lower apoptotic index (P < .05). CONCLUSIONS MIL maintained renal tissue blood flow by its vasodilatory effect, suppressed expression of TNF-α mRNA by increasing intracellular cyclic adenosine monophosphate, and ultimately decreased tubular cell apoptosis, thus protecting renal function after warm I-R injury.

One-year follow-up of treatment with once-daily tacrolimus in de novo renal transplant

OBJECTIVES The once-daily prolonged-release formulation of tacrolimus (tacrolimus QD) is expected to demonstrate equivalent efficacy and safety to the twice-daily formulation (tacrolimus BID). We reviewed the 1-year outcomes of tacrolimus QD in de novo renal transplant. MATERIALS AND METHODS We reviewed 50 de novo renal transplant patients assigned in a nonrandomized fashion to either tacrolimus QD (n=23, historic control group) or tacrolimus BID (n=27). Other immunosuppressive drugs used in both groups included mycophenolate mofetil, basiliximab, and steroids. We evaluated trough levels, required dosages, renal function, rejection rates, and episodes of infection within 1 year after transplant. RESULTS Trough levels of both drugs varied during the perioperative periods, but subsequently stabilized in both groups. There was a tendency toward a slow elevation and a higher dosage requirement in the tacrolimus QD group, compared with the tacrolimus BID group in the early stages, though the required dosages decreased steadily. The rejection rate in the tacrolimus QD group was low, and only 1 patient experienced subclinical rejection. No severe infectious adverse events were observed. CONCLUSIONS Patients taking tacrolimus QD tended to have lower trough levels and require higher dosages than those taking tacrolimus BID during the early posttransplant period, though the differences decreased with increasing time after transplant. Tacrolimus QD can be administered with excellent efficacy and safety in de novo renal transplant recipients.

Availability of Pancreatic Allograft Biopsies Via a Laparotomy

OBJECTIVE The aim of this study was to evaluate the availability of a pancreatic allograft biopsy via a laparotpmy. PATIENTS AND METHODS From September 2004 to November 2007, 17 pancreas transplantations were performed: 15 simultaneous pancreas and kidney transplantations (SPK), 1 pancreas transplant alone (PTA), and one pancreas after kidney transplantation (PAK). Thirteen pancreatic allograft biopsies were obtained via an open laparotomy. This study evaluated the complications associated with this procedure, the rate of obtaining an adequate sample, and the relationship between biopsy-proven rejections and laboratory markers. In SPK cases we evaluated the synchronization between pancreas and kidney rejection. The pancreatic samples were diagnosed according to the Drachenberg classification. RESULTS No complications resulted from the procedure. The rate of obtaining adequate samples was 84.6%. Pancreas rejection correlated with elevation of the laboratory markers in 71.4%. Simultaneous pancreas and kidney rejection occurred in 62.5%, only kidney in 25%, and only pancreas in 12.5%. CONCLUSION A pancreas graft biopsy was absolutely imperative to improve the outcome in PTA, and even in SPK cases. A pancreatic allograft biopsy via a laparotomy was a safe, necessary and easy procedure to obtain an accurate diagnosis of rejection among pancreas transplantation patients.

Temporal serum creatinine increase and exacerbation of tubulointerstitial inflammation during the first two months in resolving polyomavirus BK nephropathy

Polyomavirus BK nephropathy (BKVN) is an important complication in kidney transplantation. After immunosuppressive agents are reduced, some patients experience a temporal increase in serum creatinine (sCr) before viral clearance. The histological characteristics of re‐biopsies were therefore investigated to evaluate the time course of remission.

Effect of Cell Permeable Peptide of c-Jun NH2-Terminal Kinase Inhibitor on the Attenuation of Renal Ischemia-Reperfusion Injury in Pigs

The outcomes of organ transplantation have improved due to better immunosuppressive drugs, surgical techniques, and management of complications. However, ischemia-reperfusion injury remains a challenge affecting graft survival. In this study, we employed injection of a protein transduction domain (PTD) to inhibit the c-Jun NH2-terminal kinase (JNK) pathway thereby attenuating ischemia-reperfusion injury in a porcine model. The PTD-JNK inhibitor (JNKI) was administered into the renal artery, allowing it to be taken into various elements including vascular endothelial cells by endocytosis via the PTD. Serum creatinine and blood urea nitrogen concentrations were lower among PTD-JNKI than controls. In addition, renal tissue blood flow was maintained in the PTD-JNKI group, resulting in less tissue injury and fewer apoptotic cells. These results suggested that the PTD technique improved renal transplantation outcomes.

Living Donor Renal Transplantation Using Grafts With Multiple Arteries Procured by Laparoscopic Nephrectomy

OBJECTIVE Kidney grafts with multiple renal arteries (MRAs) are not uncommon, but they do make transplantation more difficult. Laparoscopic graft nephrectomy has become the standard; however, the safety and reliability must be maintained for both a donor and a recipient even in case of MRAs. This study evaluated the short-term outcomes of living donor renal transplant using grafts with MRAs procured by laparoscopic nephrectomy. PATIENTS AND METHODS This study reviewed all living donor kidney transplantations performed from January 2008 to June 2009, which were divided into 3 groups according to the number of renal graft arteries. The serum creatinine level, warm ischemic time (WIT), rewarming time, total ischemic time (TIT), operative time, acute rejection episodes, and complications in each group were evaluated. RESULTS The serum creatinine level showed no difference among the groups. Longer TIT was observed in the MRAs group, but WIT and rewarming time did not differ. The acute rejection rate was not different. There were no vessel complications in any donors and recipients. CONCLUSION Harvesting kidney grafts with MRAs by laparoscopic nephrectomy requires a longer TIT; however, transplantation can be performed safely and reliably for both donors and recipients.

Treatment of arteriovenous shunts after renal transplantation

PurposeImmunosuppressive drugs have improved the results of renal transplantation dramatically in recent years; however, there is still no consensus on the treatment of arteriovenous (A-V) shunts after successful transplantation. We evaluated the treatment of A-V shunts after transplantation.MethodsWe reviewed all patients who underwent shunt closure at our hospital between 2005 and 2007 assessing surgical methods, operative time, blood loss, and complications.ResultsFifty-two patients underwent shunt closure, as a simple transection in 5 patients, resection of the anastomotic site in 16, resection and reconstruction of the artery in 26, and graftectomy in 5. Graftectomy was associated with copious blood loss and a long operative time. The most frequent complication was phlebitis, but there were no nerve complications.ConclusionsAn A-V shunt after renal transplantation may result in an aneurysm, severe venous dilatation, pain, bloating of the arm, infection, and cardiac problems. Thus, after successful transplantation, shunt closure should be performed to prevent these complications and to improve quality of life.