川平 洋

バーチャル内視鏡とは,2DのMRIやCT等のデータをもとにして,コンピュータ画像処理により内視鏡で観察しているようなシミュレーション画像を作成する新しい技術である.膵癌における特徴的なバーチャル膵管鏡イメージは主膵管の狭窄と尾側主膵管の拡張である.膵癌の一部では主膵管狭窄部が内に凸の多角形状に描出された.膵管像(ERCP,MRCP,バーチャル内視鏡)が膵癌の診断にとくに有用なのは,1)TS1膵癌,2)TS2以上だがCT/MRIで描出不良の膵癌,3)主膵管内又は主膵管周囲進展傾向の強い膵癌である

症例は腹部不快感を主訴とする72歳の男性でアルコール性肝炎,口腔底癌,肺癌手術の既往歴がある.腹部超音波で肝S8に直径32mmの辺縁不整,内部不均一な呈エコー腫瘍を認めた.造影CTでは内部隔壁のみが造影され,血管造影では腫瘍はhigh-vascularで腫瘍内部に太い動脈枝を認めた.画像診断上肝細胞癌を第一にあげたが限局性結節性過形成も否定できず肝生検を施行した.しかし病理診断は正常肝組織であった.8ヵ月後腫瘍の増大を認め悪性腫瘍と診断してS8亜区域切除術を行った.腫瘍は径32×30×25mmの多結節癒合腫瘍で病理組織学診断は索状の高分化型肝細胞癌であった.術後経過は良好で再発なく外来通院中である

Background/Aims: Intraductal papillary mucinous tumors, as a cystic disease in the pancreas, clinically has a more indolent and favorable course than invasive ductal pancreas carcinoma. However, some cases of intraductal papillary mucinous tumors show invasive and rapid progression like ductal pancreas carcinoma and the prognosis of such patients is sometimes poor. In the current study, we carried out immunohistochemical staining of intraductal papillary mucinous tumor tissues for p53 and investigated whether positive staining indicates tumor malignancies and has a prognostic value for intraductal papillary mucinous tumors. Methodology: Nineteen (19) patients who underwent pancreatic resection under the diagnosis of intraductal papillary mucinous tumors at the Chiba University Hospital between April 1992 and December 1996 were studied. We performed immunohistochemical staining of p53 as well as of PCNA, Ki-67 and Bcl-2 using their respective antibodies. Pathological findings revealed that 9 cases were intraductal papillary adenoma, 9 were intraductal papillary adenocarcinoma, and one was invasive ductal papillary adenocarcinoma. Results: p53 expression could only be detected in the 1 case with invasive ductal papillary adenocarcinoma. Significant association could not be found between histological features and immunohistochemical staining of PCNA, Ki-67 and Bcl-2. Conclusions: p53 protein expression could be detected after progression to invasive type of intraductal papillary mucinous tumors. The present results demonstrate that p53 expression might be an indicator of invasive progression in intraductal papillary mucinous tumors, and might represent a surgical indicator of intraductal papillary mucinous tumors.

The prognoses of pancreatic cancer patients have been miserable even after radical surgery, and adjuvant therapy is necessary to improve the surgical results, p16(INK4a) (p16) is tight-binding and inhibitory protein for cyclin-dependent kinase 4 to induce G(1) arrest of the cell cycle. p16 gene deletion is frequently identified in human pancreas cancer. The impaired gene function of p16 might be a major factor of the uncontrolled proliferation and malignancy of pancreas cancer cells. In this study, we investigated the effect of adenovirus p16 expression vector for pancreas cancer cell proliferation to clarify whether the vector might be a promising mode to assist the surgical therapy for pancreas cancer. We constructed the adenovirus p16 expression vector AdexCACSp16 by inserting p16 cDNA to a cassette cosmid containing a nearly full-length adenovirus type 5 genome with El and E3 deletions. Thereafter, we assessed the activity of AdexCACSp16 to induce p16 gene mRNA expression in pancreas cancer cell line MIAPaCa-2 and to control cell proliferation. AdexCACSp16 induced a high level of p16 gene mRNA expression in MIAPaCa-2 cells with 1 h contact to the cells. The cell proliferation was significantly suppressed by AdexCACSp16 compared with the control adenovirus group. These data indicate that AdexCACSp16 has the potential to induce p16 gene expression and control pancreas cancer cell proliferation and that the adenovirus p16 expression vector AdexCACSp16 might be a possible method of gene therapy to improve the surgical therapeutic results for pancreas cancer.

1)nel-18欠損マウスの特に生後4週齢マウスにおける胸腺では胸腺細胞数は野生型の1/100以下に減少し,欠損型では99%以上がCD4/CD8二重陰性胸腺細胞に留まっていた. 2)欠損型と野生型の胸腺細胞と胸腺上皮の入れ換え実験を行った.欠損型胸腺細胞は野生型胸腺上皮内の環境では増殖,分化とも正常であったが,野生型胸腺細胞は欠損型胸腺上皮内では増殖,分化共にみられなかった. 3)ヌードマウスの腎被膜下に胎仔胸腺を移植,ヌードマウス由来の再構築した胸腺細胞を解析した.欠損型胸腺上皮内では胸腺細胞のCD4/CD8の分化は正常にみられたが,細胞数はコントロールに比べ1/10以下であった

粘液産生膵腫瘍10例中7例にテロメラーゼ活性を認めた.うち,組織学的にdysplasiaとされた4例中2例にも活性が検出された

mel-18 is a mammalian homolog of Drosophila melanogaster Polycomb group genes. Mice lacking the mel-18 gene show a posterior transformation of the axial skeleton, severe combined immunodeficiency, and a food-passing disturbance in the lower intestine due to hypertrophy of the smooth muscle layer. In this study, the severe combined immunodeficiency observed in mel- 18 mutant mice is correlated with the impaired mitotic response of lymphocyte precursors upon interleukin-7 stimulation. Strikingly, the axial skeleton and lymphoid phenotypes are identical in both mel-18 and bmi-1 mutants, indicating that the Mel-18 and Bmi-1 gene products might act in the same genetic cascade. These results suggest that mammalian Polycomb group gene products are involved in cell cycle progression in the immune system.