Biomedical subjects

Keiji Tsuji

Publications and source records attributed to Keiji Tsuji.

6 recordsLinked to original sources

PubMed2006

Differential gene expression and functional analysis implicate novel mechanisms in enteric nervous system precursor migration and neuritogenesis.

Enteric nervous system (ENS) development requires complex interactions between migrating neural-crest-derived cells and the intestinal microenvironment. Although some molecules influencing ENS development are known, many aspects remain poorly understood. To identify additional molecules critical for ENS development, we used DNA microarray, quantitative real-time PCR and in situ hybridization to compare gene expression in E14 and P0 aganglionic or wild type mouse intestine. Eighty-three genes were identified with at least two-fold higher expression in wild type than aganglionic bowel. ENS expression was verified for 39 of 42 selected genes by in situ hybridization. Additionally, nine identified genes had higher levels in aganglionic bowel than in WT animals suggesting that intestinal innervation may influence gene expression in adjacent cells. Strikingly, many synaptic function genes were expressed at E14, a time when the ENS is not needed for survival. To test for developmental roles for these genes, we used pharmacologic inhibitors of Snap25 or vesicle-associated membrane protein (VAMP)/synaptobrevin and found reduced neural-crest-derived cell migration and decreased neurite extension from ENS precursors. These results provide an extensive set of ENS biomarkers, demonstrate a role for SNARE proteins in ENS development and highlight additional candidate genes that could modify Hirschsprung's disease penetrance.

Animals↗

PubMed2006

A case of multiple hepatic peribiliary cysts which contributed to the obstructive jaundice and led to liver failure at the young man with von Recklinghausen's disease.

We treated a young man with obstructive jaundice, in whom multiple hepatic peribiliary cysts were detected at autopsy. He had been diagnosed with von Recklinghausen's disease in early childhood and had undergone surgery for a ventricular septal defect with massive blood transfusion at the age of 4 years. Examination at the age of 21 revealed prominent splenomegaly and a low platelet count. He underwent splenectomy and liver cirrhosis was confirmed by open biopsy of the liver. He was followed up at a local hospital and was admitted several times. When he was 41 years old, he was transferred to our hospital with severe jaundice and hepatic encephalopathy. Computed tomography showed marked dilation of the intrahepatic bile ducts and liver function tests showed that jaundice was mainly due to an increase of direct bilirubin. Despite endoscopic nasobiliary drainage, plasma exchange, and continuous hemodiafiltration, he died of hepatic failure after 5 days. At autopsy, multiple hepatic peribiliary cysts were found. Although peribiliary cysts have generally been considered to cause no symptoms, this report describes a patient with multiple hepatic peribiliary cysts which appear to have been responsible for the progression of obstructive jaundice.

Journal Article↗

PubMed2006

[A case of H. pylori and API2-MALT1 gene-negative gastric mucosa-associated lymphoid tissue lymphoma with a carcinoma-like signet-ring cell lymphoepithelial lesion].

A 60-year-old woman presented in February 2003 with an ulcer on the lesser curvature of the anglus. The endoscopic biopsy specimens showed epithelial signet-ring cell associated with lymphoid infiltration, suggesting a diagnosis of gastric cancer. Histopathological examination confirmed the diagnosis of low-grade B-cell lymphoma of MALT with epithelial signet-ring cell lymphoepithelial lesion, which was negative for H. pylori and t (11;18) (q21;q21) translocation (API2-MALT1 gene). This case was treated with H. pylori eradication and additional radiation therapy, and the tumor was disappeared.

Carcinoma, Signet Ring Cell↗

PubMed2005

A case of congenital absence of the portal vein.

We experienced a girl with congenital absence of the portal vein. She was examined by computed tomography (CT), three-dimensional computed tomographic angiography (3DCTA), digital subtraction angiography and liver biopsy. Nodular regenerative hyperplasia of the liver was detected, presumably due to an abnormal hepatocellular response to absent portal flow. 3DCTA showed that the splenic vein and superior mesenteric vein joined to form a common trunk, which directly entered the right atrium. 3DCTA may be a valuable noninvasive tool for identifying portal malformations.

Journal Article↗

PubMed2005

Use of rituximab to treat refractory Diamond-Blackfan anemia.

We report here the first case with Diamond-Blackfan anemia (DBA) who responded to rituximab. The patient is an 8-yr-old Japanese girl with refractory DBA accompanied by complex congenital heart disease. She received two doses of rituximab, 375 mg/m(2)/wk. She became transfusion independent 6 months after the treatment without any serious side effect. However, after 8 months of transfusion-free period, her condition returned to the pretreatment level with recovery of peripheral B cells. Rituximab may be a successful therapy for refractory DBA where B cells play a crucial role in the pathogenesis of the severe anemia.

Anemia, Diamond-Blackfan↗

PubMed2004

A case of latent primary biliary cirrhosis.

A 53-year-old housewife was the donor when living-related donor liver transplantation (LRLT) was performed in her younger sister (49-year-old) with terminal primary biliary cirrhosis (PBC). The donor's liver histology was diagnostic and compatible with PBC, although she was negative for antimitochondrial antibody (AMA: a specific marker of PBC) by immunofluorescence and had normal liver function tests as well as no symptoms of liver disease. In this patient with latent PBC, AMA was eventually detected by immunoblotting, although it was not detected by ELISA. These findings indicate that a family history of PBC is a risk factor for the development of this disease. Our patient was diagnosed before the advent of any clinical or biochemical indicators and before or at the onset of AMA positivity, so her liver histology revealed the earliest stage of PBC.

Journal Article↗