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Biomedical subjects

A Ooi

Publications and source records attributed to A Ooi.

52 records · Page 3Linked to original sources
PubMed1988

Expression of glial fibrillary acidic protein (GFAP) in peripheral nerve sheath tumors. A comparative study of immunoreactivity of GFAP, vimentin, S-100 protein, and neurofilament in 38 schwannomas and 18 neurofibromas.

Immunoreactivity of glial fibrillary acidic protein (GFAP) in 38 schwannomas and 18 neurofibromas was evaluated and compared with the reactivity of vimentin, S-100 protein, and neurofilament protein. All cases were positive for vimentin and S-100 protein. GFAP was positively stained in the neoplastic cells of 15 of 38 schwannomas (38%) and in two of 18 neurofibromas (11%). The extensively stained GFAP-positive tumors tended to be deeply situated in the body. The GFAP-positive cells were usually spindle-shaped and appeared preferentially in the perivascular region of hyalinized, thick blood vessels.

Adolescent↗
PubMed1988

Hepatocellular carcinoma arising in the abdominal cavity. An autopsy case of ectopic liver origin.

An unusual case of extrahepatic disseminating hepatocellular carcinoma in a 64-year-old man is reported. The initial symptom was abdominal fullness and progressive ascites. Alpha-fetoprotein in the serum was 117,000 ng/ml. Exploratory laparotomy disclosed dissemination of tumor nodules throughout the abdominal cavity without any other possible primary tumor. CT scan, ultrasonography and hepatic angiography were unable to detect any tumor lesion in the liver. The final histologic diagnosis was hepatocellular carcinoma, although at first epithelioid mesothelioma was suspected. The present case of hepatocellular carcinoma was thought to have possibly developed from ectopic liver on the peritoneum.

Abdominal Neoplasms↗
PubMed1987

Pleomorphic adenoma with a predominantly myoepithelial proliferation of the vagina.

A case of pleomorphic adenoma of the vagina in a 44-year-old woman was described. The tumor was a submucosal mass measuring 3.5 X 2 X 2 cm and located in the left lateral wall 1.5 cm inside the introitus. Histologically, it was predominantly composed of sheets and strands of spindle-shaped or polygonal cells focally dispersed in the myxoid tissue to form pseudomicrocysts. Ultrastructure demonstrated the basal lamina, desmosomes, variable amounts of filaments of both intermediate and microfilament, and occasionally microvilli in these tumor cells indicating that dominant cells were myoepithelial in nature. With immunohistochemical studies, keratin and cytokeratin were positive, whereas, S-100 protein, glial fibrillary acidic protein, vimentin, secretory component, and lysozyme were negative. The previously published cases were reviewed and compared with the present case.

Adult↗
PubMed1987

Primary T-cell lymphoma of the thyroid.

A rare case of non-Hodgkin's malignant T-cell lymphoma of the thyroid in a 79-year-old woman is reported. Light microscopically, the tumor showed diffuse proliferation of lymphoid cells, revealing prominent nuclear irregularity and occasional multilobulated nuclei, and was diagnosed as a diffuse lymphoma of medium-sized cell type. Electron microscopically, the tumor cells were seen to possess irregularly indented nuclei. Immunologic surface marker studies showed that the lymphoma cells were positive for T-lymphocyte-lineage antigens, OKT4 and OKT11, and did not react with B-lymphocyte-associated antigens. These findings indicated that the lymphoma had a T-cell phenotype.

Aged↗
PubMed1987

Hepatocellular carcinoma with chondrosarcomatous variation. A case report and review of the literature.

An autopsy case of hepatocellular carcinoma with a sarcomatous component in a 63-year-old woman was described. A massive tumor measuring 15 X 15 X 10 cm almost replaced the left lobe of the liver and extended to the right atrium of the heart. Histologically the tumor was a typical hepatocellular carcinoma of adult type, except in the central portion where there was gradual replacement of the carcinoma by spindle-shaped atypical cells with areas of chondrosarcomatous tissue. Some of the spindle cells were immunohistochemically positive for keratin, and the sarcomatous component was not found in the metastatic foci of liver and lungs. Reported cases of mixed hepatic tumor of adults in the literature were reviewed, and discussion was made concerning the nosology of the present tumor.

Carcinoma, Hepatocellular↗
PubMed1987

Gastric plasmacytoma: an early lesion diagnosed with the aid of immunoperoxidase and immunogold techniques.

A case of gastric plasmacytoma in a 34-yr-old woman has been presented. The demonstration of monotypic intracytoplasmic immunoglobulin of IgM-kappa type in biopsy specimens by immunoperoxidase technique contributed the confident histological diagnosis. In the resected stomach, IgM-kappa monoclonal proliferation of plasmacytic tumor cell was also demonstrated in the lamina propria and in the perivascular space of the submucosa, which was distinct from plasma cells of polyclonal nature diffusely infiltrating in the adjacent mucosa. The double immunogold staining confirmed the presence of immunoglobulin IgM-kappa type in the distended rough endoplasmic reticulum of the tumor cell.

Adult↗
PubMed1986

Carcinosarcoma of the esophagus. An immunohistochemical and electron microscopic study.

Immunohistochemical and electron microscopic examinations were made of a carcinosarcoma of the esophagus in an 80-year-old man. An immunohistochemical examination showed that sarcomatous spindle cells were vimentin-positive, whereas squamous carcinoma cells were keratin-positive. No coexistence of vimentin and keratin in a single tumor cell was found. Electron microscopically, the sarcomatous spindle cells were characterized by well-developed rough endoplasmic reticulum, abundant intermediate filaments, and the occasional presence of peripheral aggregates of microfilaments. No definite desmosomes were identified among these cells. These results appear to indicate that most of the spindle-shaped tumor cells assume fibroblastic cellular features and synthesize the intermediate filament protein usually expressed in mesenchymal cells, even though such tumor cells could be epithelial in origin.

Aged↗
PubMed1986

Calcitonin-producing insulinoma. An immunohistochemical and electron microscopic study.

A pancreatic endocrine tumor measuring 1.5 X 1.0 X 1.0 cm in a 67-year-old man with recurrent hypoglycemic attacks was examined by immunohistochemistry and electron microscopy. The tumor cells were relatively uniform, and almost all of them were immunoreactive to insulin. A few calcitonin-positive cells could be identified scattering in tumor cell strands, and the content of calcitonin in the tumor was 85 ng/g wet tissue. Coexistence of insulin and calcitonin in tumor cells was demonstrated by using adjacent semithin sections of the Epon-embedded material. Electron microscopically, the tumor consisted of a single type of cells with secretory granules identical to B-cell granules in the normal counterpart.

Adenoma, Islet Cell↗
PubMed1986

Papillary carcinoma of the thyroid gland with anaplastic transformation in the metastatic foci. An immunohistochemical study.

An immunohistochemical study was made on an autopsy case of papillary carcinoma of the thyroid with anaplastic transformation in the metastatic foci occurring in a 72-year-old woman. The anaplastic carcinoma cells were sarcomatous in appearance, and they were vimentin-positive and cytokeratin-negative. Whereas, papillary tumor cells which were intermingled in the anaplastic carcinoma contained both cytokeratin and vimentin. The close correlation between tumor cell anaplasia and the expression of the different intermediate filament proteins in thyroid carcinoma was briefly discussed.

Aged↗
PubMed1985

Pancreatic endocrine tumours associated with WDHA syndrome. An immunohistochemical and electron microscopic study.

Nine pancreatic endocrine tumours of patients with watery diarrhoea hypokalaemia achlorhydria (WDHA) syndrome were examined by immunohistochemistry and electron microscopy. All cases revealed neoplastic proliferation of VIP (vasoactive intestinal peptide)-immunoreactive (IR) cells. Immunoreactivity to a novel peptide hormone PHM-27, which is processed from a common big precursor peptide of VIP (prepro VIP/PHM-27), was identified in VIP-IR cells of 8 tumours. VIP-PHM-IR cells had secretory granules measuring about 130 to 220 nm in diameter. Radioimmunoassay of tumour tissue extracts showed high VIP and PHM contents in proportional amounts in most cases. According to the results of immunostaining, the 8 tumours fell into two large groups; 5 with PP (pancreatic polypeptide)-IR cells and 3 with CT (calcitonin)-IR cells. The former group demonstrated VIP cells and PP cells intermingled in various proportions, including one tumour in which coexistence of PP-IR and VIP-IR in the same cells was demonstrated. Cell heterogeneity of the tumours and possible relationships of VIP, PP and CT cells were discussed.

Adenoma, Islet Cell↗
PubMed1985

[A case of alpha-fetoprotein-producing gastric carcinoma with histologic features of embryonal carcinoma].

A case of advanced gastric carcinoma in a 75-year-old female with highly elevated serum alpha-fetoprotein (AFP) (9050 ng/ml) is presented. A Borrmann 3 type tumor measuring 7 X 7 cm was located in the gastric antrum and directly invaded up to the radix of the superior mesenteric artery. Neither the preoperative CT scan nor close examination at surgery revealed any evidence of hepatic metastasis. The histological examination showed largely embryonal (atypical-cell) carcinoma. By immunoperoxidase staining, AFP and alpha-1-antitrypsin (AAT) immunoreactivities were identified in some carcinoma cells. Sixteen cases of AFP-producing gastric carcinoma reported in Japan were reviewed.

Aged↗
PubMed1983

Myosin and actin from ascidian smooth muscle and their interaction.

Myosin and actin were purified from ascidian smooth muscle. Ascidian myosin contained two classes of light chains and the pH dependence of Ca2+-activated ATPase and the KCl dependence of actin-activated ATPase of ascidian myosin differed from those of vertebrate skeletal myosin. Troponin-tropomyosin complex from ascidian increased the ATPase activity of ascidian reconstituted actomyosin in a Ca2+-dependent manner. Ascidian myosin provided the reconstituted actomyosin with the responsiveness to calcium ions. Two actin isoforms were present in ascidian, which were distinguished by isoelectric points.

Actins↗
PubMed1983

Diagnostic aspect of spindle-cell sarcomas by electron microscopy.

Spindle-cell sarcomas in the somatic soft tissue and soft parts, including fibrosarcoma, leiomyosarcoma, malignant fibrous histiocytoma (MFH), and malignant schwannoma were examined by electron microscopy in order to delineate the most reliable cellular features for their diagnosis. Fibrosarcoma consisted largely of fibroblastic cells and leiomyosarcoma cells were packed in forming small cell groups with constant junctional complexes of nexus and zonula adherens types. MFH showed variable cellular features containing the cells with myofibroblastic and histiocytic differentiation. Malignant schwannoma was characterized by tumor cells having slender cytoplasmic processes with overlapping or interdigitation and thick basement membrane. These ultrastructural features were contributory to the differential diagnosis of the sarcomas examined.

Adult↗
PubMed1983

An ultrastructural study on periductal elastosis in human breast tumors.

An ultrastructural study on elastosis of human breast tumors was made with special attention to the periductal elastosis and the cell responsible for elastic fiber formation. The elastosis was found prominently in scirrhous type of duct carcinoma. In the area of mild periductal elastosis, the elastic fibers with many microfibrils and a tiny central elastin were seen around the periductal fibroblasts which were characterized by attenuated cytoplasms with aggregates of microfilaments and slightly developed rough endoplasmic reticulum. With the thickening of the periductal wall, such an area was replaced by abundant mature elastic fibers with peripheral microfibrils and a few intervening ordinary fibroblasts. Therefore, it was suggested that the periductal fibroblasts which transformed into ordinary fibroblasts during the development of elastosis were primarily concerned with the elastic fiber formation. In the interlobular tissue in which both fibroblasts and myofibroblasts were present, the elastic fibers were larger than those of the periductal area and had less microfibrils in their periphery. The relationship between microfibrils and elastin during the early elastosis, maturation process of the elastic fibers, and cell modulation of the fibroblasts in the breast elastosis were discussed.

Adenofibroma↗
PubMedDate not supplied

Electron microscopic and immunoelectron microscopic demonstration of pancreatic polypeptide cells in glucagonoma: colocalization of pancreatic peptide and glucagon in single secretory granules.

We describe a case of pancreatic tumor in a 65-year-old woman with typical glucagonoma syndrome. Plasma glucagon (GL) and pancreatic polypeptide (PP) were markedly elevated up to 1404 and 1200 pg/ml, respectively. Histologic examination of the metastatic tumors in liver and lymph nodes showed endocrine-type tumors composed of GL-positive cells some of which coexpressed PP immunoreactivity. Electron microscopy revealed the tumor cells with single-type secretory granules similar to normal A cell granules. Double immunogold staining demonstrated both GL and PP immunoreactivities in the same secretory granules. Biologic and diagnostic significance of coexpression of PP and GL in a single secretory granules of pancreatic endocrine tumors is discussed briefly.

Adenoma, Islet Cell↗