Biomedical subjects

G Asano

Publications and source records attributed to G Asano.

At least 109 records · Page 6Linked to original sources

PubMed1995

[Roles of myofibroblasts in the stroma of human gastric carcinoma].

The stromal reaction of human gastric carcinoma was studied about myofibroblast proliferation and collagen type I, III synthesis in 28 surgical materials (15 cases of well differentiated type, 13 cases of poorly differentiated type), using immunohistochemical and immunoelectron microscopical techniques. Immunohistochemically, myofibroblasts showed marked reactivity to both anti-alpha smooth muscle actin (alpha SM-1) MAb and anti-vimentin MAb, and they were broadly distributed in the stroma of gastric carcinomas. Moreover, myofibroblasts revealed their own characteristics surrounding collagenous fibers under electron microscope. The myofibroblast proliferation was more prominent in poorly differentiated carcinoma and invasive carcinomas. On the other hand, much more myofibroblasts were observed in the marginal portion of cancer nests than the central area. The distribution of collagen type III was very similar to that of myofibroblast. These findings suggest that the proliferation of myofibroblast and collagen synthesis in tumor stroma were obvious host response against carcinomas, and this phenomenon may reveal an important biological status in gastric carcinoma.

Adenocarcinoma↗

PubMed1995

Role of vascular endothelial growth factor in angiogenesis of rheumatoid arthritis.

OBJECTIVE: To examine the localization and role of vascular endothelial growth factor (VEGF), an endothelial cell specific mitogen, in rheumatoid arthritis (RA). METHODS: Immunohistochemical staining, reverse transcription polymerase chain reaction (RT-PCR) analysis and in situ hybridization for VEGF were performed on synovial tissues from 10 patients with RA, 5 patients with osteoarthritis (OA) and 3 autopsy cases. RESULTS: In RA, the proliferative ratio of synovial lining cells and vascular endothelial cells was significantly higher than that in OA and normal synovial tissues. Immunohistochemical staining demonstrated that VEGF polypeptide was strongly expressed in subsynovial macrophages, fibroblasts surrounding microvessels, vascular smooth muscle cells, and synovial lining cells, but not in vascular endothelial cells of patients with RA. On the other hand, in patients with OA and normal cases, VEGF polypeptide was slightly expressed in synovial lining cells and fibroblasts. RT-PCR showed a positive reaction for VEGF messenger RNA in RA, OA, and normal synovial tissues. A large number of subsynovial macrophages, fibroblasts, vascular smooth muscle cells, and synovial lining cells from patients with RA expressed VEGF mRNA using in situ hybridization. CONCLUSION: In RA, VEGF is synthesized and released by a large number of subsynovial macrophages, fibroblasts surrounding microvessels, vascular smooth muscle cells, and synovial lining cells and may stimulate endothelial proliferation in a paracrine manner via VEGF receptors.

Arthritis, Rheumatoid↗

PubMed1994

Production of interleukin-1 by primary cultured parenchymal liver cells (hepatocytes).

The production of interleukin-1 (IL-1) by cultured parenchymal liver cells was revealed by a biological assay with an IL-1-dependent cell line, Northern blot analysis, and in situ hybridization. Inhibition experiments on the IL-1 activity with anti IL-1 alpha antibody also support the presence of IL-1 alpha in the supernatant of cultured parenchymal liver cells. Based on these results, we discuss the possibility of IL-1 production by parenchymal liver cells in vivo.

Animals↗

PubMed1994

Fibronectin biosynthesis in endothelial regeneration after intimal injury.

In this experiment, we sought to identify the major fibronectin (FN) synthesizing cells, the source of FN production, and the role of FN in intimal regeneration. In rats in which vascular endothelial denudation had been induced, serial morphologic changes after intimal injury were studied by light and electron microscopic examination using immunohistochemical techniques and in situ hybridization. At 2 weeks after intimal injury, regenerated endothelial cells had pleomorphic cytoplasm and loose cellular junctions. Immunohistochemically, factor VIII-related antigen was localized in the regenerated endothelial cells, and immunoreaction products of FN were increased in the thickened neointima. Ultrastructurally, FN was localized in the proliferated endoplasmic reticulum of regenerated endothelial cells in the intima, while the alpha 5 subunit of alpha 5 beta 1 integrin, one of the fibronectin receptors, was localized in the plasma membrane and increased endoplasmic reticulum of regenerated endothelial cells. FN mRNA was localized in a large number of regenerated endothelial cells (87.2 and 89.8%) by in situ hybridization at 2 and 4 weeks after intimal injury. These findings indicate that FN may mainly contribute to endothelial cell functions such as spreading and adhesion in the regenerative stage.

Animals↗

PubMed1994

The efficacy of aldose reductase inhibitor, antioxidant butylated hydroxytoluene and cysteine protease inhibitor E64 on hyperglycemia-induced metabolic changes in the organ-cultured bovine lens.

It is well known that polyol related sugar cataract formation is preventable with aldose reductase inhibitor (ARI) and newly developed different kinds of ARIs have been extensively studied for potential clinical use. The potency of AD-5467 ARI (Takeda) on hyperglycemic lenses was evaluated by measuring of phosphate metabolites in phosphorus-31, (31P) nuclear magnetic resonance (NMR) spectra. Moreover, the effects of antioxidant butylated hydroxytoluene (BHT) and cysteine protease inhibitor E64 on hyperglycemic lenses were evaluated for comparative study, since some studies showed that these agents also possess the delay or preventive effects in sugar cataractogenesis. The lenses were dissected out from bovine eyes and incubated in Dulbeco's modified Eagles (DME) media containing 5.6 mM and 40 mM glucose with or without the ARI, BHT, E64 for 24 hours. These were assessed by MNR spectrometer operating at 109.25 MHz for 31P. The morphologic changes of the lenses were revealed by histologic and ultrastructural examinations. The lenses incubated in high glucose medium showed significant decreased levels of adenosine triphosphate (ATP), associated with increased inorganic phosphates and sugar phosphates levels. The lenses treated with ARI or E64 showed 70% to 80% protection of ATP levels and those with BHT showed 100% protection of ATP levels. These results indicated that sugar catractogenesis is multifactorial process in which the other mechanisms are also involved besides the polyol pathway mechanism.

Aldehyde Reductase↗

PubMed1994

Melanotic neuroectodermal tumor of infancy in the skull associated with high serum levels of catecholamine. Case report.

The case of a 5-month-old boy with a left retromastoid melanotic neuroectodermal tumor of infancy is presented. The tumor extended from the subcutaneous tissue of the occiput to the cerebellar hemisphere. Histologically, the epidural part of the tumor was composed of undifferentiated neuroblasts, dense connective tissue, and glandular structures lined by melanin-containing cuboidal cells, whereas the subdural part contained differentiated neuroblasts and melanin-containing cells. The preoperative high serum levels of adrenaline, noradrenaline, vanillylmandelic acid, and neuron-specific enolase returned to normal after two operations and two cycles of chemotherapy; however, the dopamine level was mildly elevated. These data and immunohistochemical and ultrastructural findings strongly suggest that melanotic neuroectodermal tumor of infancy is derived from the neural crest.

Catecholamines↗

PubMed1994

Process of basement membrane re-formation after intimal denudation.

During re-endothelialization after intimal denudation induced by balloon catheter in the rat aorta, re-formation of the basement membrane (BM) was examined in samples taken 15 min, 3, 7, 14, 21 and 28 days after the balloon-induced injury. Although the luminal surface of the aortic wall was covered by round-shaped regenerating endothelial cells (ECs) by 7 days after intimal denudation, no continuous BM structure was detectable until 21 days. Periodic acid-thiosemicarbazide gelatin-methenamine silver (PATSC-GMS) staining for electron microscopy and immunostaining of type IV collagen and laminin demonstrated the accumulation of BM components underneath the regenerating ECs after 14 days. The expression of type IV collagen mRNA was revealed in regenerating ECs by in situ hybridization. A continuous BM structure first appeared 21 days after intimal denudation and was almost complete by 28 days. Simultaneously, the regenerating ECs flattened and attached more closely to the BM than in earlier phases. In conclusion, we consider that the regenerating ECs produce the BM components and suggest that reorganization of the newly formed BM is important in the process of differentiation of regenerating ECs.

Animals↗

PubMed1994

[Morphological atypism and clinicopathological factors in colorectal adenoma and cancer using nuclear DNA content, p53 and PCNA].

Cytofluorometric analysis of DNA content and immunohistochemical examination of p53 and PCNA were performed in colorectal adenomas, mainly borderline lesions, and cancers. Nuclear DNA content revealed aneuploidy and polyploid cells in severely atypical adenomas and cancers. Mutated p53 protein was also observed in severely atypical adenomas, especially tortuous and villous lesions and cancers. PCNA labeling index (P-I) was significantly increased in proportion to cell atypism and P-I over 50% was noted in half of severely atypical adenomas. Among infiltrating cancers, poorly differentiated adenocarcinoma showed high P-I. However, well differentiated adenocarcinoma infiltrating beyond the tunica muscularis propria showed various P-I values depending on the presence of metastasis to lymph node or blood vessel invasion. Furthermore, P-I in the metastatic lesion was significantly higher than that of primary lesion. These results suggest that severely atypical adenomas showing morphological features such as an increased N/C ratio, loss of polarity, roundish nucleus, tortuous and villous change of gland have malignant potentiality. So severely atypical adenomas have the clinical indication for polypectomy. In addition, poorly differentiated adenocarcinoma shows high proliferative ability and metastatic lesions or poorly differentiated components existing in infiltrating cancers may affect cancer development as productive clones.

Adenocarcinoma↗

PubMed1993

Serum and tissue measurements of CA72-4 in ovarian cancer patients.

Serum levels of cancer-associated antigen 72-4 (CA72-4) (tumor-associated glycoprotein 72; TAG-72) from 106 patients with primary ovarian cancer were measured by an immunoradiometric assay employing the monoclonal antibodies (MAbs) B72.3 and CC49. Immunohistochemical localization of TAG-72 was also investigated using immunoperoxidase methodology in conjunction with both light and electron microscopy. In using a cutoff value of 4.0 U/ml for the serum assay, sensitivity of all primary ovarian carcinomas was 63.2% (67.6% of mucinous cystadenocarcinomas and 66.7% of serous cystadenocarcinomas), while specificity of benign ovarian tumors was 91.1%. Diagnostic characteristics of CA125 and CA72-4 have been demonstrated by receiver-operating-characteristics analysis. Although CA125 expressed a remarkable diagnostic efficiency with serous cystadenocarcinoma, it was less efficient with mucinous cystadenocarcinoma. CA72-4, however, was highly detectable for any histological type of ovarian cancer. Immunohistochemical staining with MAbs B72.3 and CC49 in the cytoplasm was stronger than that in the cell membrane in tissues from mucinous cystadenocarcinomas. Also, histological localization of TAG-72 in the microvilli and apical cytoplasmic membrane was demonstrated by electron microscopy using MAb B72.3 and samples of seromucinous cystadenocarcinoma (mixed type). Consequently, TAG-72 was useful for the detection of ovarian carcinoma, especially for monitoring mucinous cystadenocarcinoma, and it is localized in the microvilli and apical cytoplasmic membrane of cystadenocarcinoma cells.

Adenocarcinoma↗

PubMed1993

Effect of mixing ratio in lecithin/bile acid mixed micelles on Na(+)-K+ ATPase.

Lecithin and bile acid form mixed micelles in the bile. We found that the mixing ratio in lecithin/bile acid mixed micelles directly changes the activity of Na(+)-K+ ATPase. Na(+)-K+ ATPase activity was suppressed to 13.3% of that in the buffer alone at a lecithin/bile acid mixing ratio of 0.1 in the presence of 10(-2) M bile acid (that is, a concentration level close to that of the hepatic bile). With increase in the mixing ratio in the presence of 10(-2) M bile acid, the activity of the enzyme was found to be augmented accordingly. Thus addition of lecithin to an extent such that the mixing ratio reached 0.6 led to an enhancement of enzymatic activity to 193.8%. If lecithin addition is made in the presence of bile acid at the near gallbladder concentration of 10(-1) M, however, the Na(+)-K+ ATPase activity can be observed to increase with the increase in the lecithin/bile acid ratio. Yet, at the same mixing ratio of 0.6, the enzyme activity was arrested at only 25.7%. However, this change in mixing ratio had no effect on ouabain-insensitive ATPase. The state of mixed micelles may exert the same effect on Na(+)-K+ ATPase activity in vivo.

Animals↗

PubMed1993

Ethanol-elicited structural and biochemical alterations in mitochondrial ATPase in cultured myocardial cells.

The effects of ethanol (12.5-500 mM for up to 24 h) on mitochondrial structure including that of ATPase particles in cultured ventricular myocardial cells were studied using negative-stain electron microscopy. The activity of mitochondrial ATPase after ethanol treatment was also examined cytochemically and biochemically. At 5 min after the addition of all the concentrations of ethanol examined, some mitochondrial cristae were expanded and the arrangement of mitochondrial ATPase particles on these cristae was disordered. At and after 30 min the cristae decreased in number and some were expanded, vesiculated or fragmented. ATPase particles also decreased in number, particularly after the application of ethanol in concentrations of more than 50 mM. All the mitochondria had broadened and translucent cristae, and lacked ATPase particles with 200 and 500 mM ethanol at 24 h, although with 12.5 and 50 mM ethanol some mitochondria had similar negatively stained images but others had ATPase particles on broadened cristae. The enzymatic activity of the mitochondrial ATPase was unchanged with 200 and 500 mM ethanol at 24 h, compared with controls. The cytochemical technique also detected enzyme activity with all the concentrations of ethanol examined at 24 h. The discrepancy between the structural and biochemical alterations in mitochondrial ATPase induced by ethanol is discussed.

Adenosine Triphosphatases↗

PubMed1993

Effect of vitamin E on vascular integrity in cholesterol-fed guinea pigs.

This study was designed to clarify the effects of vitamin E on the alterations in proteoglycan distribution and vascular permeability, which were examined by immunohistochemical and ultrastructural techniques in the aortas of cholesterol-fed guinea pigs. The animals were divided into three groups: a control group, a cholesterol group, and a vitamin E group. Serum levels of cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, and thiobarbituric acid-reactive substances were measured. An increase in thiobarbituric acid-reactive substances was observed in the cholesterol group compared with control and vitamin E groups. Intimal atheromatous lesions of the aorta were significantly decreased in the vitamin E group compared with the cholesterol group. Histochemically, an increased distribution of proteoglycans such as chondroitin, dermatan, and heparan sulfates and ruthenium red reaction products in the intima; decreased glycocalyx on the endothelial surface; and increased permeability to horseradish peroxidase were revealed in the cholesterol group compared with the vitamin E group. Hypercholesterolemia, resulting in superoxide production, may have contributed to the endothelial damage and increased permeability to plasma proteins and lipids in the vascular wall of the cholesterol group. However, vitamin E administration inhibited lipid deposition and development of this abnormal permeability associated with an irregular distribution of proteoglycan. These results suggest that vitamin E preserves the morphological and functional integrity of the vascular wall and may contribute to the inhibition of atherogenesis in cholesterol-fed guinea pigs.

Animals↗

PubMed1993

[Correlation between adherence ability and construction of basement membrane-like scaffold of HeLa-S3 cells in nude mouse tumor].

We selected a subclone of HeLa-S3 cells to depict the relationship between cellular adherence to the extracellular matrix and pathological features of tumors derived from these cells. The selected subclone (PA cells) adheres poorly to type-IV collagen as compared to the wild type cells (EA cells) which attach easily to type-IV collagen. In vitro, it was confirmed that PA cells adhered poorly to type-IV collagen even after a long term of culture and showed weaker chemotactic activity toward this BM component. Injected into nude mice, PA cells formed smaller tumors than EA cells. Histologically, both derived tumors showed construction of basement membrane-like scaffolds that stained positively for type-IV collagen and laminin. EA cell tumors demonstrated frequent absence of and thinning and gaps in their basement membrane, which shows the invasive activity of the tumors. PA cell tumors showed a more regular basement membrane with predominant desmoplasia.

Animals↗

PubMed1993

[Immunohistochemical study of borderline thyroid lesions with special reference to relationships among nuclear features, type IV collagen and malignancy of follicular lesions].

It is very difficult to differentiate follicular adenoma from follicular carcinoma in thyroid follicular lesions. The authors investigated the biological behavior of these thyroid follicular lesions using immunohistochemical techniques. Specimens taken from normal thyroid, 2 cases; follicular adenoma, 9; atypical adenoma, 7; and follicular carcinoma, 8; were observed. Proliferating cell nuclear antigen (PCNA) is a marker of cellular proliferation. Nucleoli are also increased in number and move to the nuclear margin in cases of cellular proliferation. The PCNA labeling index was calculated by counting the number of PCNA-positive cells per 2,000 tumor cells. PCNA labeling indices were 0.025% in the normal thyroid, 1.41% in follicular adenoma, 5.73% in atypical adenoma, and 6.16% in follicular carcinoma, respectively. Nucleoli retaining rate of the tumor cells were 40.0% in follicular adenoma, 63.7% in atypical adenoma, and 71.8% in follicular carcinoma. Rates of nucleolus margination were 20.9% in follicular adenoma, 34.4% in atypical adenoma, and 36.0% in follicular carcinoma. Changes in the basement membrane were morphologically classified into three groups as follows; membrane structure almost preserved (group I), partial discontinuity (breaks) (group II), and widespread absence of membrane structure (group III), based on immunohistochemical investigation of Type IV collagen. Group I was demonstrated in 8 cases of follicular adenoma and one case of atypical adenoma. Group II was observed in one case of follicular adenoma, 3 cases of atypical adenoma and 3 cases of follicular carcinoma. In addition, group III was noted in 3 cases of atypical adenoma and 5 cases of follicular carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma, Follicular↗

PubMed1993

[Immunohistopathological properties of cytoskeletal proteins and extracellular matrix components in pleomorphic adenomas of salivary glands].

Twenty-five pleomorphic adenomas and 10 normal salivary glands were immunohistochemically studied with respect to cytoskeletal proteins and extracellular matrix components to observe the relationship between these components and the differentiation of tumor cells in pleomorphic adenomas. For immunohistochemical observation, keratin (AE1), vimentin (V9), alpha-smooth muscle actin (1A4) and type IV collagen (JK-199) were studied by means of monoclonal antibodies, and laminin (LM) and fibronectin (FN) were analysed with polyclonal antibodies. AE1 was localized in inner tubular cells, and 1A4 was identified in spindle and leiomyomatous cells. These observations may provide evidence of differentiation into ductal epithelia and myoepithelial cells, respectively. Positive staining for V9 in cuboidal cells suggests dedifferentiation. The extracellular matrix components, JK-199, LM and FN, were localized in surrounding areas of cells stained by V9 and/or 1A4. This suggests that expression of these cytoskeletal proteins and extracellular matrix components may affect each other, and ther by contribute to cellular differentiation and production of extracellular matrix.

Adenoma, Pleomorphic↗

PubMed1993

[The role of Ca(2+)-ATPase and oxygen radical in reperfusion injury of rat liver].

The effects of ischemia and reperfusion with and without oxygen radical scavengers and xanthine oxidase inhibitors on Ca(2+)-ATPase activity were examined in the rat liver of 5 min ischemia followed by 5 and 10 min reperfusion. Ischemia was produced by the ligation of right hepatic artery and right portal vein. Superoxide dismutase, catalase and allopurinol were administered by subcutaneous injection of 60,000U/kg, 90,000U/kg and 200mg/kg, respectively before ligation. Reaction products of Ca(2+)-ATPase were morphometrically analyzed by RUZEX IIIU. Histochemically, Ca(2+)-ATPase activities were demonstrated on plasma membrane of liver cells, bile canaliculi and Kupffer cells involving mitochondria in liver cells of control rats. Ca(2+)-ATPase activities were depressed in the central lobes of liver after 5 min ischemia followed by 5 and 10min reperfusion. However, the activities of Ca(2+)-ATPase were not depressed by addition of oxygen radical scavengers and xanthine oxidase inhibitor before ischemia. These results suggest that oxygen free radicals may influence Ca(2+)-ATPase activity and contribute to liver cell damage due to ischemia-reperfusion.

Animals↗

PubMed1993

[Expression of type III and IV procollagen, prolyl 4-hydroxylase mRNAs in fibrotic human liver].

In situ localization of type III, IV procollagen and prolyl 4-hydroxylase mRNAs were examined to clarify the collagen production in fibrotic human liver. These mRNAs were localized in hepatocytes and mesenchymal cells in the areas of liver fibrosis. In alcoholic liver disease, the expression was promoted, and positive cells were diffusely observed in nodules. These results suggest that hepatocytes along with mesenchymal cells produce collagens, and correlate with pericellular fibrosis and sinusoidal capillarization in alcoholic liver disease.

Gene Expression↗

PubMed1993

[Study on proliferating potential by Ag-NORs staining in human pancreatic carcinoma].

NORs (Nucleolar Organizer Regions) are loops of DNA encoding ribosomal RNA, which reflect cellular activity. The Ag-NORs staining was applied to paraffin sections of 10 normal pancreas, 10 chronic pancreatitis and 23 pancreatic cancer, with 17 gastric and 18 colonic cancers. We calculated the mean Ag-NORs number and Ag-NORs index, and defined T/N ratio. The mean Ag-NORs number was compared with the data obtained by Flow cytometry (FCM) in pancreatic carcinoma. A significant difference in Ag-NORs index was found between benign (normal: 1.86 +/- 0.38, pancreatitis: 2.14 +/- 0.53) and malignant tissues (4.02 +/- 1.19) of the pancreas (p < 0.01). Compared with the data by FCM, there was a significant correlation between the mean Ag-NORs number and the percentage of S-phase cells in pancreatic carcinoma (r = 0.59, p < 0.01). Ag-NORs index in pancreatic carcinoma showed significantly lower value than that in cancer of stomach (6.35 +/- 1.32) and colon (7.66 +/- 1.35), but there was no difference in T/N ratio among them. In conclusion, the Ag-NORs staining is useful for analyzing proliferating activity in pancreatic carcinoma. The proliferating potential in pancreatic carcinoma is lower than that in gastric and colonic ones. This may be due to the low proliferating potential of the background mucosa from which pancreatic carcinoma will arise.

Cell Division↗