Yoji Yamazaki

Infrared ray electronic endoscopy combined with indocyanine green injection for detection of sentinel nodes of patients with gastric cancer.

To avoid unnecessary lymphadenectomy in patients with cancer accurate diagnosis of the sentinel lymph node (SLN) is important.

Tenascin-C regulates angiogenesis in tumor through the regulation of vascular endothelial growth factor expression

In order to verify whether tenascin‐C (TN‐C) is involved in angiogenesis as an extracellular signal molecule during tumorigenesis, cancerous cell transplantation experiments and coculture experiments were carried out, focusing on the regulation of vascular endothelial growth factor (VEGF). The A375 human melanoma cells introduced the GFP gene (A375‐GFP), implanted subcutaneously into BALB/cA nude (WT) and TN‐C knockout BALB/cA nude (TNKO) congenic mice. Furthermore, coculture experiments between A375‐GFP and embryonic mesenchyme, which was prepared from both genotypes, were carried out to investigate the molecular mechanism in the cell‐cell interactions. Both the content of TN‐C and that of VEGF in the tumor and the conditioned medium were analyzed by the sandwich ELISA method. Seven days after transplantation of the A375‐GFP, capillary nets became far more abundant in the tumors grown in WT mice than those in TNKO mice. Interestingly, VEGF and TN‐C expressions showed antithetical expression patterns between the tumors in WT mice and those in TNKO mice. This peculiar phenomenon seems to be caused by a time lag prior to the onset of the mesenchymal regulation for the TN‐C expression of A375‐GFP. The coculture experiments revealed that WT mesenchyme had a much stronger effect than TNKO mesenchyme on both TN‐C and VEGF expression. However, the defects of TNKO mesenchyme were restored in all cases by additional TN‐C. These results clearly indicated that the expressions of both TN‐C and VEGF depend on the surrounding mesenchyme, and that the function of mesenchyme is regulated by its own mesenchymal TN‐C. In conclusion, the present data suggest that the matrix microenvironment organized by the host mesenchyme is very important for angiogenesis in tumor development.

Adeno-Associated Viral Vector-Mediated Expression of Endostatin Inhibits Tumor Growth and Metastasis in an Orthotropic Pancreatic Cancer Model in Hamsters

We examined the feasibility of using adeno-associated virus (AAV)-mediated systemic delivery of endostatin in gene therapy to treat metastasis of pancreatic cancer. We established an animal model of orthotopic metastatic pancreatic cancer in which the pancreatic cancer cell line PGHAM-1 was inoculated into the pancreas of Syrian golden hamsters. Transplanted cells proliferated rapidly and metastasized to the liver. An AAV vector expressing endostatin (5 × 1010 particles) was injected intramuscularly into the left quadriceps or intravenously into the portal vein. These routes of vector administration were evaluated by comparing various parameters of tumor development. Intramuscular injection of the vector modestly increased the serum endostatin level. The numbers of metastases and the incidence of hemorrhagic ascites were decreased in the treated animals. In contrast, the serum concentration of endostatin was significantly increased after intraportal injection of the vector. The antitumor effects on all parameters (including the size and microvessel density of primary pancreatic tumors, the sizes and number of liver metastases, and the incidence of hemorrhagic ascites) were significant. These results suggest that systemic delivery of endostatin represents a potentially effective treatment for pancreatic cancer and liver metastases. The route of vector administration influences the efficacy of AAV-mediated endostatin expression. Intraportal injection of the AAV vector appears to be more effective as an antiangiogenic gene therapy for pancreatic cancer.

Experimental analysis of the Ill effect of anomalous pancreaticobiliary ductual union

An ideal canine model of anomalous pancreaticobiliary ductal union, similar to a human anomaly, was devised. Direct anastomosis of the dorsal pancreatic duct and the choledochus was employed (dorsal pancreaticocholedochostomy). The ventral pancreatic duct was not manipulated. Cylindrical choledochal dilatation results in 13 out of 20 adult dogs and in 4 out of 6 puppies. Dilatation of the intrahepatic biliary tree and thickening of the choledochal wall in a hepatic direction were observed in high ratio among adult dogs. Puppies had less dilatation. The activation of pancreatic enzymes was studied in bile containing pancreatic juice. The proteolytic enzymes, trypsin and elastase were proven to be activated in the bile without the presence of enterokinase in the pancreaticocholedochostomy model. This would be the cause of the ill effects of refluxed pancreatic juice into bile in anomalous pancreaticobiliary ductal union.

Spontaneous rupture of splenic hamartoma: A case report

Splenic hamartomas are rare. The authors report a case of spontaneously ruptured splenic hamartoma in a 5-month-old boy. This rupture led to the death of the child. If abdominal pain is present and a mass is palpated, the splenic hamartoma should be managed surgically in an expeditious manner. There have been only two known previous reports of spontaneous rupture of splenic hamartoma in adults, but none in children.

Implantation of Rectal Cancer in an Anal Fistula: Report of a Case

A 53-year-old man who had had an anal fistula for 20 years was admitted to our hospital with a large intestinal obstruction. Barium enema and colonoscopy confirmed advanced rectal cancer and we palpated a soft tumor, 3 cm in diameter, with inflammatory induration on the right side of the rectum. After draining a perianal abscess caused by the anal fistula, we performed low anterior resection. Histological examination of the perianal necrotic tissue obtained during resection of the perianal tumor encompassing the anal fistula revealed adenocarcinoma. Since the histology of the perianal lesion was identical to that of the rectal cancer, a diagnosis of cancer implantation rather than carcinoma originating in the anal fistula was entertained. Although the recurrence of rectal cancer by mucosal implantation is not uncommon, the coincidental implantation of rectal cancer in an anal fistula is extremely rare.

Usefulness of radio-guided surgery using Technetium-99m. Methoxyisobutylisonitrile for primary and secondary hyperparathyroidism

The efficacy of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI)-guided surgery for detecting abnormal parathyroid glands in patients with secondary hyperparathyroidism (2-HPT) was evaluated and compared with the results from the same examination in patients with primary hyperparathyroidism (1-HPT). The results were also compared with those found by ultrasonography (US) and preoperative 99mTc-MIBI scintigraphy was also made. At operation 99mTc-MIBI accumulated in 64 nodules of 15 cases of 2-HPT, and all of 60 parathyroid swellings were detected (true-positives 60, sensitivity 100%, accuracy 94%). In the cases of 1-HPT, 99mTc-MIBI revealed 11 hot nodules in 10 cases, and the evaluation was true-positive 10, sensitivity 100%, and accuracy 91%. US and preoperative 99mTc-MIBI scintigraphy in patients with 2-HPT had a sensitivity of 75% and 67% and an accuracy of 70% and 66%, respectively. The usefulness of 99mTc-MIBI-guided surgery for detecting abnormal parathyroid tissue in 2-HPT patients was similar to that in 1-HPT patients but was superior to US and preoperative 99mTc-MIBI scintigraphy. Intraoperative 9mTc-MIBI for patients with 2-HPT is effective and makes the surgery easier, especially when the parathyroid glands are ectopic or when a few glands are markedly enlarged but the other glands are atrophied.

An extremely large solitary primary paraganglioma of the lung: report of a case.

We present herein the case of a 38-year-old woman found to have an extremely large solitary primary paraganglioma of the lung. The patient presented with chest pain on exertion and a mass was discovered in the left lower lobe of the lung by chest X-rays and computed tomography (CT). As no other neoplasms were detected elsewhere, a left lower lobectomy was performed. The patient has remained well without any evidence of recurrence for 5 years since her operation. The tumor, measuring 13×12×7 cm, was composed of ovoid cells (Zellballen), which were positive for Fontana-Masson and Grimelius stains, and sustentacular cells. Immunohistochemically, the ovoid cells were positive for neuron-specific enolase, S-100, CAM5.2, Leu7, and chromogranin A, and negative for carcinoembryonic antigen and epithelial membrane antigen. The sustentacular cells were positive for S-100 protein and CAM5.2, and negative for glial fibrillary acid protein. Therefore, the tumor was diagnosed as a paraganglioma. The tumor from our patient is the largest of the 17 solitary primary pulmonary paragangliomas reported thus far in the English-language literature.

Laparoscopic splenectomy in children

To determine the safety and efficiacy of laparoscopic splenectomy (LS) in children, a retrospective review of our preliminary experience using LS was compared to results in patients who previously underwent open splenectomy (OS). From July 1993 to January 1995, we performed eight LS procedures in six children with hereditary spherocytosis (HS) and two with immune thrombocytopenic purpura (ITP). Laparoscopic cholecystectomy was simultaneously done in one case with HS. There were 4 males and 4 females who ranged in age from 5 to 15 years—an average age of 8.8 years. Two cases in the early series required a counterincision because of bleeding. Eleven patients who previously underwent OS in our department were used to compare demographics, operative courses, and surgical outcomes. The ages, genders, diseases, body weights, and spleen weights were comparable between LS group and OS groups. The operative time for the LS group was statistically longer than for the OS group (226±24 min vs 101±8 min, P<0.001). The estimated blood loss in the LS group was similar to that of the OS group (100±39 ml vs 73±11 ml, P=0.97). There were no peri- or postoperative complications in two groups. The postoperative hospital stay of LS group was statistically shorter than that of the OS (6.8±0.6 days vs 10.4±0.5 days, P<0.001). LS provided better cosmesis and minimized trauma in children over OS. LS appears to be a safe and effective procedure in children, and is useful in the management of pediatric patients with HS or ITP.

Kugel herniorrhaphy: clinical results of 124 consecutive operations.

PurposeDue to its recent clinical application, the results of Kugel herniorrhaphy have not yet been well documented. We analyzed our experience in performing 124 consecutive Kugel herniorrhaphies at a single institute.MethodsSince the first introduction of Kugel herniorrhaphy in Japan in September 2001, a total of 117 patients (124 hernias) have undergone this procedure at our institute. The operative technique of Kugel herniorrhaphy was directly obtained through two hands-on training courses that were given by Dr. Kugel. The clinical results of the 124 hernias were analyzed, and to understand the feasibility of performing Kugel herniorrhaphy for various types of hernias, the operation time and the necessity for dividing the hernia sac were compared among each type based on the Nyhus classification.ResultsThe operation times in types 2, 3A, 3B, 3C, and 4 were 48.5 ± 19.5, 45.9 ± 19.9, 54.2 ± 24.8, 52.5 ± 10.6, and 64.4 ± 56.7 min, respectively, and the differences between each group were not statistically significant. In type 3A, no patient required a division of the hernia sac (0%), in contrast to 43% in type 3B. Peritoneal injury during operation and local hematoma/seroma were the most common complications (8.1% and 8.9%, respectively). Postoperatively the patients’ quality of life factors, such as the analgesics needed, number of days before a return to normal activity, number of days before a return to work, and the recurrence rate of 0.9%, were comparable with other tension-free herniorrhaphy findings reported in the past.ConclusionOur results suggest that Kugel herniorrhaphy is equally feasible for all types of Nyhus classifications, including femoral and recurrent hernias.