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Biomedical subjects

T Saku

Publications and source records attributed to T Saku.

At least 55 records · Page 3Linked to original sources
PubMed1993

Immunocytochemical localization of basic fibroblast growth factor in carcinomas and inflammatory lesions of the human digestive tract.

BACKGROUND: Basic fibroblast growth factor (bFGF) is one of the important angiogenic peptides. Clarification of its localization in human cancer and inflammatory diseases is important for the study of angiogenesis. EXPERIMENTAL DESIGN: Sliced human gastrointestinal carcinomas and inflammatory lesions were frozen after fixation. Immunocytochemical localization of bFGF was studied at the light and electron microscopic levels. RESULTS: In gastric carcinoma of the diffuse type, bFGF was mainly observed in some of the endothelial cells of the microvasculature and in fibroblasts. Gastric carcinoma of the intestinal type and colonic carcinoma showed the immunoreactivity in fibroblasts, vascular endothelial cells, and in the extracellular matrix (ECM). Carcinoma cells were occasionally positive. In inflammatory lesions, bFGF was most prominent in the ECM. Areas of deposition of bFGF in the ECM partly corresponded to areas of increased immunoreactivity for heparan sulphate proteoglycan. Immunoelectron microscopically, bFGF was localized in the cytosol of fibroblasts and cancer cells but no localization was observed in the lumen of rough endoplasmic reticulum or perinuclear space in any of the cells observed. bFGF was also localized along the luminal surface of vascular endothelial cells, in nuclei of fibroblasts, vascular endothelial cells, smooth muscle cells, and some cancer cells, and in the ECM. CONCLUSIONS: Extensive localization of bFGF in the ECM was related to the areas of increased vascular permeability and active angiogenesis. In cancer tissues, the distribution pattern of bFGF supports a paracrine mechanism among mesenchymal cells rather than a direct paracrine mechanism on vascular cells from carcinoma cells. Nuclear localization of bFGF may support its activity as a transcriptional factor.

Colon↗
PubMed1992

Basement membranes in adenoid cystic carcinoma. An immunohistochemical study.

Tissue samples from 30 patients with adenoid cystic carcinoma and 20 with adenocarcinoma of salivary gland origin were studied by immunohistochemical staining with specific antibodies to the four macromolecules that are present in normal basement membranes: type IV collagen, laminin, heparan sulfate proteoglycan, and entactin. In the adenoid cystic carcinoma samples, the four proteins were localized in different types of extracellular matrices in the tumor, namely pseudocystic spaces, hyaline stroma, and around tumor cell nests. The staining intensity was enhanced by pretreatment with hyaluronidase. The tumor cells of adenoid cystic carcinoma showed a tendency to proliferate with individual cells in contact with the basement membrane and to infiltrate through basement membrane-rich tissues, such as peripheral nerves, blood vessels, and skeletal muscles. In contrast, only circumferential staining of tumor cell nests was obtained in adenocarcinoma samples. The results suggest that adenoid cystic carcinoma is a tumor with affinity for basement membranes, and this basic feature is reflected in its histology and presumably in its biologic behavior. Immunostaining with antibodies to basement membrane proteins appears to be useful for differential diagnosis of some types of these two carcinomas.

Adenocarcinoma↗
PubMed1992

Histopathologic and ultrastructural studies of oral mucosa with Candida infection.

Eighteen oral mucosal biopsies with Candida infection were studied with light and electron microscopy. Under light microscopy, candidal infected oral mucosa was classified with epithelial hyperplasia, 15 cases and epithelial dysplasia, three cases. Four of 15 epithelial hyperplasias showed marked parakeratosis, and high grade acanthosis with many eosinophilic cells in the spinous cell layers. Epithelial dysplasia was characterized by atrophy of the spinous cell layers and increased nucleocytoplasmic ratio in the basal cell layers. Ultrastructurally, candidal infected oral mucosa showed numerous small desmosomes and the interdigitation of cytoplasmic membranes between spinous cells in both epithelial hyperplasia and epithelial dysplasia. Moreover, eosinophilic spinous cells, observed predominantly in epithelial hyperplasia showed intricate arrangement of dense tonofibrils. These ultrastructural findings seemed to give rise to mechanical strength between spinous cells in oral mucous epithelium with Candida infection. Results in this study suggest that excessive hyperplasia of candidal infected oral mucosa might be a protective reaction to the invasion of candidal pseudohyphae, but not associated with precancerous conditions.

Aged↗
PubMed1992

Immunohistochemical demonstration of enamel proteins in odontogenic tumors.

Immunohistochemical localization of two enamel proteins, amelogenin and enamelin, in comparison with that of keratin, was determined in odontogenic tumors and the allied lesions in order to verify functional differentiation of the tumor cells as ameloblasts. Amelogenin and enamelin were demonstrated in small mineralized foci and in the tumor cells surrounding them in adenomatoid odontogenic tumor (AOT), calcifying epithelial odontogenic tumor (CEOT), and calcifying odontogenic cyst (COC). Hyaline droplets in AOT showed positive staining for both enamel proteins. These mineralized and hyaline materials were not positive for keratin, although tumor cells were positive. On the other hand, no immunoreaction for enamel proteins was obtained in ameloblastoima and odontogenic epithelial cell nests within myxoma and epulis. The results suggest that tumor cells of AOT and CEOT and lining epithelial cells of COC show ameloblastic differentiation in part, but that ameloblastoma cells do not attain functional matauration as secretory phase ameloblasts.

Ameloblastoma↗
PubMed1991

An immunocytochemical study on distinct intracellular localization of cathepsin E and cathepsin D in human gastric cells and various rat cells.

Immunocytochemical localization of two distinct intracellular aspartic proteinases, cathepsins E and D, in human gastric mucosal cells and various rat cells was investigated by immunogold technique using discriminative antibodies specific for each enzyme. Cathepsin D was exclusively confined to primary or secondary lysosomes in almost all the cell types tested, whereas cathepsin E was not detected in the lysosomal system. The localization of cathepsin E varied with different cell types. Microvillous localization of cathepsin E was found in the intracellular canaliculi of human and rat gastric parietal cells, rat renal proximal tubule cells, and the bile canaliculi of rat hepatic cells. The immunolocalization of each enzyme in gastric cells were essentially the same in humans and rats. In the gastric feveolar epithelial cells and parietal cells, definite immunolabeling for cathepsin E was observed in the cytoplasmic matrix, the cisternae of the rough endoplasmic reticulum, and the dilated perinuclear envelope. In rat kidney, cathepsin E was detected only in the proximal tubule cells, while cathepsin D was found mainly in the lysosomes of the distal tubule cells but not in those of the proximal tubule cells. These results clearly indicate the distinct intracytoplasmic localization of cathepsins E and D and suggest the possible involvement of cathepsin E in extralysosomal proteolysis that is related to specialized functions of each cell type.

Animals↗
PubMed1991

Lectin histochemistry of cystic jaw lesions: an aid for differential diagnosis between cystic ameloblastoma and odontogenic cysts.

The binding sites for Ulex europaeus agglutinin I (UEA-I), Bandeirea simplicifolia agglutinin I (BSA-I), and peanut agglutinin (PNA) were comparatively examined in the surgical materials from 41 cases of cystic and solid ameloblastomas and 42 cases of non-neoplastic odontogenic cysts including dentigerous cyst, odontogenic keratocyst, and radicular cyst. In non-neoplastic cysts, most of epithelial lining layers gave positive binding with UEA-I and BSA-I. However, no positive reactions were obtained for these two lectins in the epithelial components of ameloblastoma, except for limited UEA-I binding to markedly keratinized tumor cells in four cases. PNA binding was irregular and did not make any clear distinction between ameloblastomas and cysts. The results suggest that the lectin staining for UEA-I and BSA-I is a useful histologic aid for differential diagnosis between cystic ameloblastoma and non-neoplastic jaw cysts.

Ameloblastoma↗
PubMed1990

Characterization of hemoglobin-hydrolyzing acidic proteinases in human and rat neutrophils.

The nature and levels of hemoglobin (Hb)-hydrolyzing acidic proteinases including cathepsin D and cathepsin E, which were most active at pH 3.5-4.0, were enzymatically and immunochemically compared between human and rat neutrophils. By subcellular fractionation and immunoprecipitation with discriminative antibodies specific for each enzyme, cathepsin D was shown to be present in the granular content fraction of both human and rat neutrophils and to account for about 35% of the total Hb-hydrolyzing activity. Cathepsin E was observed mainly in the cytoplasmic fraction of rat neutrophils from peripheral blood and peritoneal exudates and accounted for about 65% of the total activity, but it was not detected in human blood neutrophils. Immunoelectron microscopy on rat neutrophils revealed that cathepsin D was exclusively confined to lysosomes, whereas cathepsin E was localized mainly in the cytoplasmic matrix and often in the perinuclear spaces and the rough endoplasmic reticulum. The non-cathepsin D activity in human neutrophils, which represented about 65% of the total activity, appeared to be due to a serine proteinase, since it was inhibited by diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride and was not inhibited by agents specific for aspartic-, cysteine-, or metallo proteinases. The enzyme(s) responsible for this activity was largely associated with the granular membranes, and a half of it could be described as an integral membrane protein on the basis of phase separation with Triton X-114 at 35 degrees C. The levels of these Hb-hydrolases in gingival crevicular fluid from human chronic inflammatory periodontitis patients were examined in order to clarify their participation in the periodontal tissue breakdown.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Autoantibodies to keratin in Sjögren's syndrome.

In order to determine which components of the salivary duct cells are recognized by the antisalivary duct antibodies, sera of patients with Sjögren's syndrome were screened for immunoreactivity to keratin by using an ELISA test and a Western blot analysis. The autoantibodies which reacted with keratin were demonstrated in 8 of 9 definite cases of Sjögren's syndrome and in 3 of 6 probable cases, and they reacted with different keratin peptides in each case. The results suggest that the antisalivary duct antibodies include antibodies against keratin, which exists ubiquitously as a cytoskeleton in the salivary gland epithelial cells. Detection of antikeratin antibody might be a useful aid for diagnosis of Sjögren's syndrome.

Adult↗
PubMed1990

Immunolocalization of basement membrane molecules in the stroma of salivary gland pleomorphic adenoma.

In order to determine the participation of basement membrane molecules in formation of its characteristic stroma, 30 cases of salivary gland pleomorphic adenoma were examined by immunohistochemical staining for type IV collagen, laminin, heparan sulfate proteoglycan, and entactin. The stroma was histopathologically classified into four types: hyaline, fibrous, myxoid, and chondroid. Immunohistochemically, type IV collagen and laminin were more intensively localized in hyaline, fibrous and chondroid types of stroma, whereas heparan sulfate proteoglycan was more prominent in myxoid areas. The results suggest that the stroma contains these basement membrane components, which are possibly biosynthesized by epithelial tumor cells, and that histological variety of the stroma depends on proportion of local contents of each basement membrane molecule.

Adenoma, Pleomorphic↗
PubMed1990

Cathepsins D and E in normal, metaplastic, dysplastic, and carcinomatous gastric tissue: an immunohistochemical study.

Immunohistochemical distributions of cathepsins D and E were determined in normal mucosa, metaplastic, dysplastic, and cancerous lesions of the human stomach. Cathepsins D and E were localised in the foveolar epithelium and parietal cells of the normal gastric mucosa, but their intracytoplasmic distributions were different - cathepsin E distribution was even and diffuse in the cytoplasm while cathepsin D was found in coarse intracytoplasmic granules. Chronic inflammation and ulcer did not influence the distribution of these enzymes. No positive staining was obtained in the incomplete type of intestinal metaplasia, dysplasia, and well differentiated adenocarcinoma. Tumour cells of signet ring cell carcinoma and poorly differentiated adenocarcinoma cells, however, gave strong and diffuse stainings for cathepsins D and E in the cytoplasm. The results suggest that the distribution of cathepsins D and E is related to each specialised function of the foveolar epithelium and the parietal cells, and that their disappearance is associated with development of well differentiated adenocarcinoma from intestinal metaplasia.

Adenocarcinoma↗