Naotake Akutsu

Sentinel lymph node mapping for gastric cancer using a dual procedure with dye- and gamma probe-guided techniques

BACKGROUND Increasing evidence supports the sentinel lymph node (SN) concept for melanoma and breast cancers. SN biopsy may replace routine lymph node dissection in the treatment of these cancers. But there are little data evaluating this concept in patients with gastric cancer. The objective of this study was to test the feasibility of SN mapping in gastric cancers by using the dual-mapping procedure with dye and radioactive colloid. STUDY DESIGN Thirty-one consecutive patients preoperatively diagnosed as T1-2 and N0 underwent SN biopsy using the dual-mapping procedure. Distributions of SNs identified by the dye-guided technique (blue nodes; BNs) were compared with those identified by the gamma probe guided technique (hot nodes; HNs). RESULTS Among the 31 patients, 7 were found to have lymph node metastases. All positive nodes were detected by SN biopsy using the dual method. So, an accuracy rate of 100% was achieved in predicting the status of regional lymph nodes. Both BNs and HNs were identified in 28 of 31 patients (90%), but significant discrepancy of distribution was noted between BNs and HNs. Among the 28 patients with identified BNs, there was one metastasis in a non-BN. So the accuracy rate was 96% for the dye-guided technique. In contrast, among the 28 patients with identified HNs, 2 patients had metastasis in non-HNs, making the accuracy rate 93% for the gamma probe-guided technique. CONCLUSIONS SN mapping is feasible in gastric cancer, but the dye-guided and gamma probe-guided techniques are complementary. So we recommend the dual-mapping procedure.

Living donor pancreas transplantation in Japan

Background/purposeLiving-donor pancreas transplants (LDPs) were introduced at Chiba-East National Hospital in 2004, and 12 LDPs have been performed at this institution to date. Based on the outcome of these 12 LDPs, the efficacy and safety of LDPs are herein discussed.MethodsTwelve diabetic patients underwent LDPs; ten had simultaneous pancreas and kidney transplants from living donors, one had pancreas transplant after a kidney transplant from a living donor, and one had a pancreas transplant alone from a living donor. The donors were parents or brothers and the ABO blood types were incompatible in three LDPs. The procedures for the donor and recipient operations were performed according to the technique established by the University of Minnesota. Bladder drainage was used in 11 recipients and enteric drainage was used in one patient. Tacrolimus, basiliximab, mycophenolate mofetil, and prednisone were used for induction and immunosuppressive treatment. A splenectomy, double-filtered plasmapheresis, and plasma exchange were added in the ABO-incompatible LDPs.ResultsNo complications were observed in the donors during hospitalization. The 1-year survivals of the patients, kidney grafts, and pancreas grafts were 100, 100, and 100%, respectively. The 3-year survivals were 91.7, 90, and 91.7%, respectively. Three patients developed leakage of pancreatic juice and one patient required a surgical procedure. Cytomegalovirus antigenemia was detected in five patients (42%).ConclusionsBased on the excellent outcome of the LDPs at this institution, LDPs is therefore expected to become a promising option for the treatment of patients with severe diabetes.

Cryopreservation of human pancreatic islets from non-heart-beating donors using hydroxyethyl starch and dimethyl sulfoxide as cryoprotectants.

Although widely used, DMSO is toxic for pancreatic islets. We combined hydroxyethyl starch (HES) with DMSO to simplify the procedure of freezing and thawing, and to decrease the toxicity of DMSO. A preclinical study was performed using islets from beagle dogs. After storage for 4 weeks, the islets were thawed and examined. The islet structure was well maintained after thawing. Although the number of the islets decreased to 71.2 ± 20.1%, the function of the islets was evaluated by static incubation after thawing and showed a 1.80 ± 0.78 stimulation index. We have introduced this technique for the cryopreservation of human islets from non-heart-beating donors. Twelve cases of human islet cryopreservation were performed. The sample tube of each human cryopreservation was thawed to evaluate the morphology, contamination, and endocrine function. Although fragmentation was observed in five samples (41.6%), the other seven (58.4%) showed a normal structure when evaluated by microscopic and electron microscopic study. The stimulation index (SI) of static incubation deteriorated from 3.37 ± 3.02 to 1.34 ± 0.28 after thawing. We divided the thawed islets into two groups: group 1 (n = 8), SI >1.2; group 2 (n = 4), SI <1.2. The group 1 islets showed a higher rate of normal structure (87%) than did group 2 (25%). Moreover, the SI before cryopreservation was 4.01 ± 3.57 in group 1, which was higher than the SI of 2.11 ± 0.72 in group 2. Based on the good results from the preclinical study using a large-animal model, this method was introduced for clinical application. Even from the pancreata of non-heart-beating donors, a successful islet cryopreservation was achieved. However, the isolated islets with poor function should not be cryopreserved for transplantation.

Two Cases of Calcineurin Inhibitor-Associated Reversible Posterior Leukoencephalopathy Syndrome in Renal Transplant Recipients

Reversible posterior leukoencephalopathy syndrome (RPLS) is one of the important side effects of calcineurin inhibitors (CNIs). Magnetic resonance imaging (MRI) of the brain is useful for the diagnosis of RPLS, showing the edema primarily in the cortex and subcortical white matter of the posterior brain regions. Interruption of CNIs is essential for the treatment of patients with RPLS. Herein we have described 2 cases (1.7%) of RPLS induced by CNIs after kidney transplantation. The first case was a 56-year-old man with chronic renal failure due to diabetic nephropathy who received a living-related kidney transplantation in 2006. Initial immunosuppressive therapy consisted of cyclosporine, mycophenolate mofetil (MMF), prednisolone, and basiliximab. Four months after transplantation, he developed unconsciousness and paralysis. The second case was a 24-year-old woman with end-stage renal disease due to Alport syndrome who received an ABO-incompatible living-related kidney transplantation. Initial immunosuppressive therapy consisted of tacrolimus, MMF, prednisolone, and basiliximab. On postoperative day 3, she developed convulsions and unconsciousness. In both patients, RPLS was diagnosed with neurological symptoms and MRI findings at early stage of the disease, and they recovered rapidly from the disease by the interruption of CNIs. Our data demonstrated that early diagnosis and immediate interruption of CNIs were essential for the treatment of RPLS after kidney transplantation.

Clinical islet transplantation in Japan.

INTRODUCTION The results of clinical islet transplantation in Japan are, here in, reported and discussed its efficacy and problems. METHODS Since the first islet transplantation was performed in 2004, 65 islet isolations and 34 islet transplantations to 18 type 1 diabetic patients have been performed in Japan. RESULTS Following islet transplantation, patients experienced decreased insulin requirements and lower hemoglobin A1C levels, and positive serum C-peptide levels. All patients achieved stabilized blood glucose levels and the disappearance of hypoglycemic unawareness. Although three patients achieved insulin independency for a limited period, persistent islet graft function was difficult to maintain. Overall islet graft survival was 86.5% at 6 months, 78.7% at 1 year, and 62.9% at 2 years after the first islet transplantation. In our institution, we carried out 23 islet isolations and six islet transplantations to four patients. Although insulin independency was not achieved, all patients showed a disappearance of hypoglycemic unawareness. CONCLUSIONS Using data from the Japanese Trial of Islet Transplantation, the effectiveness of islet transplantation was shown even when using the pancreata from non-heart-beating donors. Although there are a number of problems to be solved and further improvement is needed, we can state that the introduction of clinical islet transplantation offers hope for type 1 diabetic patients.

Laparoscopic‐assisted distal pancreatectomy and nephrectomy from a live donor

BackgroundThe simultaneous transplantation of pancreas and kidney from live donors is performed in select countries. One of the reasons for this reduced applicability is the invasiveness of the donor operation. We propose the method of laparoscopic-assisted operation to be performed on live donors with minimal invasion.MethodThe donor was placed in the right lateral decubitus position. A 7-cm upper midline incision was made, and a handport was installed in addition to two or three 12-mm ports. After the removal of the left kidney graft, the spleen and the distal part of the pancreas were completely mobilized. The splenic vein and artery were identified and mobilized. The donor was then rotated to a supine position. Dissection of the pancreatic parenchyma using ultrasound shears and ligation of the splenic vessels were performed through midline incision under direct vision. The distal part of the pancreas and the spleen were extracted.ResultsSince December 2007, 3 donors have undergone this operation. In all 3 cases, the postoperative course was uneventful, and both the renal and pancreatic grafts functioned well.ConclusionThis technique is minimally invasive and safe, and may become the standard method of live donor operation for simultaneous pancreas–kidney transplantation.

Evaluation of Segmental Pancreatic Function Using 11C-Methionine Positron Emission Tomography for Safe Operation of Living Donor Pancreas Transplantation

For the safe operation of living donor pancreas transplantation, we investigated the utility of 11C-methionine positron emission tomography (PET) to examine the function of the residual pancreatic head in patients with pancreatic disease undergoing distal pancreatectomy and in living donors of pancreas transplantation. After 6 hours of fasting, we intravenously injected 370 to 740 MBq 11C-methionine. PET was scanned 30 minutes after injection. 11C-methionine PET uptake by the pancreatic head versus body/tail was expressed as a standardized uptake value (SUV). The SUVs of the pancreatic head were compared before versus after surgery. The SUVs of the pancreatic head in patients before and after distal pancreatectomy were 15.3 +/- 6.0 and 18.2 +/- 2.4, respectively. The SUVs of the pancreatic head in donors before and after distal pancreatectomy were 16.1 +/- 1.0 and 14.7 +/- 1.4, respectively. Both patients and donors showed no significant difference in SUVs of the pancreatic head before and after surgery. However, the SUVs of the residual pancreatic head were elevated after distal pancreatectomy in 80% of patients and 50% of donors. These data indicated that the function of the pancreatic head may be maintained or improved after distal pancreatectomy. 11C-methionine PET may become a potent modality to evaluate segmental pancreatic function for a safe living donor operation.

Successful Islet Transplantation From the Pancreata of Non-Heart-Beating Donors

We performed 6 islet transplantations in 4 type 1 diabetes mellitus patients. From September 2003 to April 2007, 23 islet isolations were performed from pancreata of non-heart-beating donors. The pancreata preserved using a 2-layer method or simple cold storage in University of Wisconsin solution were transferred to our cell processing center. The islet isolation was performed according to the Edmonton protocol with some modifications. The immunosuppressive protocol was achieved using sirolimus, tacrolimus, and anti-CD25 antibody (basiliximab). Islet yield was 400 to 491,040 IEQ and purity was 1% to 70%. Stimulation indices upon static incubation were 1.38 to 11.69. All patients who underwent islet transplantation showed positive serum C-peptide levels immediately after transplantation. Although insulin independence was not achieved, they displayed stabilized blood glucose levels, reduced insulin doses, and disappearance of hypoglycemic unawareness. Although stomatitis and diarrhea due to the side effects of sirolimus were observed in 2 patients, there were no severe complications. In patient 1, serum C-peptide levels decreased gradually from 1 year after transplantation. In conclusion, successful islet transplantation was possible using islets isolated from the pancreata of non-heart-beating donors. Further improvements are needed to achieve prolonged graft survival.

p53-Dependent and -independent transactivation by the E6 protein of human papillomavirus type 16.

The mechanism by which the E6 protein of human papillomavirus type 16 (HPV-16) transactivates heterologous virus promoters has not been established. In this study, the involvement of p53-mediated transcriptional repression in transactivation by the HPV-16 E6 protein was examined using several virus promoters. HPV-16 E6 transactivated the TATA box-containing simian virus 40 early promoter and the Rous sarcoma virus long terminal repeat in p53-containing cells but not in p53-deficient cells. In contrast, the adenovirus E2 promoter was transactivated both in p53-containing and p53-deficient cells. These results indicate that the transactivation activity of the HPV-16 E6 protein is mediated by p53-dependent and promoter-specific p53-independent pathways.

Effectiveness of Hydroxyethyl Starch (HES) on Purification of Pancreatic Islets

BACKGROUND The isolation of large-scale and high-quality islets from the pancreas is essential for a successful islet transplantation. We developed a hydroxyethyl starch (HES)-Collins solution as the purification medium and evaluated its usefulness on islet isolation from the pancreas of beagle dogs. MATERIALS AND METHODS The pancreas of beagle dog was digested using our original 2-step automated technique. Islets were purified by discontinuous purification method on HES-Collins solution (group 1, n = 10) or Euro-Ficoll solution (group 2, n = 16) with a COBE2991 cell processor. Islet yield and purity, changes in islet number during 3-day cultures, static incubation, perifusion study, and insulin content were examined. In addition, the islets were autotransplanted into the liver via the portal vein. RESULTS Although no significant differences were detected, yield and purity were higher in group 1. After 3 days of culture, the islet number decreased less in group 1. Both under static incubation and in the perifusion study, stimulation indices were 4.50 +/- 1.82 and 6.02 +/- 1.05, which were significantly higher than the 2.18 +/- 0.67 and 3.32 +/- 1.46 observed in group 2. Also, insulin content of the islets was significantly higher in group 1 than in group 2. Fasting blood glucose levels were maintained at values below 100 mg/dl for 100 days in group 1 and around 200 mg/dl in group 2. CONCLUSIONS The use of HES-Collins solution was associated with an improvement of islet yield and purity. Also, islet viability and function were preserved longer during culture. Accordingly, islet purification using HES-Collins solution might be recommended for clinical islet transplantation.