Yutaka Sanada

Novel NF1 gene mutation in a Japanese patient with neurofibromatosis type 1 and a gastrointestinal stromal tumor

Many mutations of the NF1 gene have been reported in patients with neurofibromatosis type 1 (NF1); however, there have been no documented NF1 gene mutations in Japanese NF1 patients. In the present study, we used the polymerase chain reaction (PCR) and DNA sequencing analysis to characterize the NF1 gene in a 53-year-old Japanese patient with NF1 who suffered from neurofibroma, pheochromocytoma, and gastrointestinal stromal tumor (GIST). Direct sequence analyses revealed a single base substitution in the splicing donor site of intron 6 (IVS6 888+1, G → A) in one NF1 allele, resulting in an altered splice site (ss) in the mutated allele. Splicing at the cryptic 5′ ss in the mutated allele generated mRNA with an insertion of 60 nucleotides. In addition, we screened for mutations in exons 9, 11, 13, and 17 of the c-kit gene in GIST and the succinate dehydrogenase subunit D (SDHD) gene in the pheochromocytoma, but we did not detect any somatic mutations. We report here the first case of an NF1 patient with four neoplasms: neurofibroma, pheochromocytoma, astrocytoma and GIST. Our results suggest that the molecular pathogenesis of GISTs in NF1 patients is different from that in non-NF1 patients.

Aberrant Methylation of the Netrin-1 Receptor Genes UNC5C and DCC Detected in Advanced Colorectal Cancer

BackgroundUNC5C and DCC, the netrin-1 receptors, belong to the functional dependence receptors family, which shares the ability to induce apoptosis in the absence of their ligands. Recently, two reports indicated that UNC5C and DCC methylation was closely associated with loss of gene expression in colorectal cancer. These results prompted us to examine the methylation status of the UNC5C and DCC genes in the colorectal carcinomas we surgically removed.MethodsThe methylation status of the UNC5C and DCC genes were examined in primary carcinomas and the corresponding normal tissues derived from 50 patients with colorectal cancer using quantitative methylation-specific polymerase chain reaction (qMSP). The correlation between the methylation status and the clinicopathologic findings was then evaluated.ResultsAberrant methylation of the netrin-1 receptor genes were detected in 41 of the 50 (82%) primary colon cancers, suggesting that the aberrant methylation of netrin-1 receptors was frequently observed in colorectal cancer. The clinicopathologic data were then correlated with this result.ConclusionsA significant difference was observed in the Dukes stage (p = 0.0438). Netrin-1 receptors might act as a tumor suppressor in colorectal cancers, and thus methylation might present a malignant potential in colorectal cancer.

Specific detection of Epstein-Barr virus in inflammatory pseudotumor of the spleen in a patient with a high serum level of soluble IL-2 receptor

Abstract: A case of inflammatory pseudotumor of the spleen is described in a 63-year-old woman who presented with an intrasplenic tumor and an elevated serum level of soluble interleukin 2 receptor (sIL-2R). Microscopic examination after removal of the spleen revealed that the tumor was composed of mixed cellular infiltrates, mainly lymphocytes and plasma cells, and spindle-cell proliferation. Epstein-Barr virus (EBV) was specifically detected in the tumor by in situ hybridization for EBV RNA. The serum level of sIL-2R level was normalized after splenectomy. EBV infection may play a role in the development of splenic inflammatory pseudotumor and the elevation of sIL-2R level.

Downregulation of Mus81 as a novel prognostic biomarker for patients with colorectal carcinoma

The Mus81 gene encodes a critical endonuclease involved in DNA repair and tumor suppression. Our previous study has shown reduced expression of Mus81 in hepatocellular carcinoma and its association with the metastastic potential and prognosis of hepatocellular carcinoma. However, the role of Mus81 in colorectal carcinoma is currently unknown. We therefore carried out the present study to explore the correlation between Mus81 expression and the progression of colorectal carcinoma. Mus81 expression in 92 cases of colorectal carcinoma and matched normal tissues was determined by quantitative real‐time polymerase chain reaction. Our results showed that Mus81 expression in colorectal carcinoma tissues was significantly reduced compared with the corresponding normal tissues (P < 0.001) and the downregulation of Mus81 (decreased by more than 50%) was found in 60.9% (56/92) of colorectal carcinoma. Moreover, Mus81 downregulation correlated significantly to hepatic metastasis (P = 0.019) and a high TNM stage (P = 0.025) of colorectal carcinoma. In addition, the decrease of Mus81 was also detected in 10 cases of hepatic metastasis tissues compared with the corresponding primary colorectal carcinoma tissues (P = 0.016). More importantly, colorectal carcinoma patients with apparent Mus81 downregulation have shown significantly poorer overall survival than those with little Mus81 downregulation (P = 0.0374). Also, multivariable Cox regression analysis identified Mus81 downregulation as an independent prognostic factor for colorectal carcinoma (hazard ratio, 1.678; P = 0.040). In conclusion, the reduced expression of Mus81 is closely related to hepatic metastasis and poor prognosis of colorectal carcinoma, indicating Mus81 as a novel prognostic marker for colorectal carcinoma. (Cancer Sci 2011; 102: 472–477)

Comparison of endorectal ileal pullthrough following colectomy with and without ileal reservoir

In an experimental study, 18 dogs underwent total colectomy, mucosal proctectomy, and endorectal ileal pullthrough with ileoanal anastomosis. In 6 dogs, no internal reservoir was constructed (NR). In 6 additional dogs, an S-shaped ileal reservoir (SR) was constructed immediately above the peritoneal reflection. In 6 other dogs, a side-to-side ileal reservoir (SS) of 15-cm length was constructed above the peritoneal reflection. At 12 wk postoperatively, there was a 231% increase in volume of the SS reservoir, whereas the SR increased 85% and the NR increased 78%. Dogs with NR experienced high stool frequency with low water absorption and minimal dilatation. Dogs with SR experienced dilatation rapidly, reducing stool frequency but causing stasis and moderate to severe inflammation of the ileal mucosa. Dogs with SS of at least 15-cm length enlarged sufficiently to reduce stool frequency and increase water absorption slightly without causing stasis or appreciable inflammation.

Meningoencephalocele Associated with Tripterygium wilfordii Treatment

We treated a male infant with occipital meningoencephalocele associated with the taking of Tripterygium wilfordii. The infant was delivered normally at 38 weeks of gestation with a huge cystic mass protruding from the occiput. He was diagnosed with occipital meningoencephalocele and cerebellar agenesis. His mother had taken T. wilfordii for rheumatoid arthritis early in her pregnancy. T. wilfordii is a herbal medicine used for rheumatoid arthritis and male contraception. Since its toxicity is high and its use during pregnancy is restricted, it is the most likely cause of this infants anomalies.

Specific mutation in exon 11 of c-kit proto-oncogene in a malignant gastrointestinal stromal tumor of the rectum.

Abstract: Gastrointestinal stromal tumor (GIST) in the distal third of the rectum was detected in a 57-year-old man who underwent an abdominoperineal resection of the rectum. Because the tumor expressed CD34 and c-kit gene product, but did not express smooth muscle actin or S-100 protein, it was diagnosed as an uncommitted type of GIST. Moreover, a specific mutation in the sequence coding the juxtamembrane domain in exon 11 of the c-kit proto-oncogene was revealed by a polymerase chain reaction-single-strand conformation polymorphism method. One year after resection, the patient developed multiple liver metastases. It is suggested that a specific mutation in exon 11 of the c-kit proto-oncogene may have played an essential role in the development of the liver metastases.

Prevention of reactive oxygen-induced endothelial cell injury by blocking its process.

Endothelial cell (EC) injury induced by reactive oxygen species (ROS) was investigated and effects of Ca²⁺ channel blockers, agents which elevate intracellular cAMP levels ([cAMP]_i), and protein kinase inhibitors on H₂O₂-induced EC injury were analyzed using human umbilical vein EC cultures. Exposure to H₂O₂ increased intracellular Ca²⁺ levels and decreased [cAMP]_i. Ca²⁺ channel blockers, [cAMP]_i-elevating agents, and protein kinase inhibitors significantly inhibited H₂O₂-induced EC injury. Data suggest that H₂O₂-induced EC injury is mediated by extracellular Ca²⁺ influx, intracellular cAMP efflux, and intracellular signaling, each of which is blocked by Ca²⁺ channel blockers, [cAMP]_i-elevating agents, or protein kinase inhibitors. It is suggested that ischemia/reperfusion injury induced by ROS may be prevented by Ca²⁺ channel blockers, [cAMP]_i-elevating agents, and protein kinase inhibitors.

High Calorie Infusion-induced Hepatic Impairments in Infants

Hepatic impairments have been reported sporadically in infants receiving long-term high calorie infusion. Some characteristic hepatic impairments induced with high calorie infusion at the Juntendo University Hospital, Tokyo, are studied in 18 surgical infants, with discussion of the possible etiology of this complication in the context of high calorie infusion. The hepatic dysfunctions were classified into 3 types by sequential liver function determinations: Type I with a transient and slightly elevated serum transaminase without elevation of alkaline phosphatase; Type II, an elevation of alkaline phosphatase and total and direct bilirubin without elevation of serum transaminase; Type III, a marked and prolonged elevation of aklaline phosphatase, total and direct bilirubin, and serum transaminase. The etiology of these hepatic impairments during high calorie infusion is unknown.

A technique using a rectus abdominis muscle flap in the treatment of adult congenital tracheoesophageal fistulas

The authors successfully treated an adult with congenital tracheoesophageal fistula (TEF) Gross-C type by the addition of an effective pedicled muscle flap. This patient had undergone 2 thoracotomies when he was an infant at another hospital; however, the fistula recurred. After transection and closure of the fistula, a right rectus abdominis muscle flap between the 2 stumps was interposed. The current case followed a favorable postoperative course; neither fistula nor abdominal hernia occurred.