Biomedical subjects

S Katsuda

Publications and source records attributed to S Katsuda.

At least 73 records · Page 4Linked to original sources

PubMed1990

Localization of PDGF-B protein in macrophages in all phases of atherogenesis.

Lesions of atherosclerosis occur in the innermost layer of the artery wall and consist primarily of proliferated smooth muscle cells surrounded by large amounts of connective tissue, numerous lipid-laden macrophages, and varying numbers of lymphocytes. Growth-regulatory molecules may be involved in intimal accumulation and proliferation of smooth muscle cells responsible for the occlusive lesions of atherosclerosis. Platelet-derived growth factor (PDGF) B-chain protein was found within macrophages in all stages of lesion development in both human and nonhuman primate atherosclerosis. Thus macrophages may play a critical role in the disease by providing PDGF, a potent chemotactic and growth-stimulatory molecule, to the intimal smooth muscle cells.

Animals↗

PubMed1990

Mechanism of gallium 67 accumulation in inflammatory tissue.

The present study was undertaken to elucidate the accumulation mechanism of gallium 67 in inflammatory tissue. 67Ga accumulation in inflammatory tissue was observed by macro- and microautoradiogram. Permeability indices were calculated for serum albumin from blood vessels into inflammatory and normal tissue. Neutrophils and macrophages did not play a major role in 67Ga accumulation in the inflammatory tissue because 67Ga could hardly be detected in the sites in which neutrophils were crowded; the accumulation was concentrated in the intercellular space around these cells in the tissue. Permeability indices for inflammatory tissue were much greater than those for normal tissues. It is thought from the present study and previously reported results that 67Ga, together with plasma from permeable blood vessels, readily penetrates the inflammatory tissue and stays there by binding to the acid mucopolysaccharide present in the tissue.

Animals↗

PubMed1990

Abnormal accumulation of elastin-associated microfibrils during elastolysis in the arterial wall.

We examined the correlation between elastolysis and abnormal accumulation of microfibrils in the arteries of rabbits using light and electron microscopic and tissue culture techniques. Partial constriction of the common carotid arteries of rabbits gave rise to gradual atrophy of the media with elastolysis and an unusual accumulation of microfibrils. With advancing experimental atherosclerosis in cholesterol-fed rabbits, the elastofibrotic intima generally became thick and hyalinized and was replaced by bundles of microfibrils lacking elastin or associated with only tiny elastin aggregates and disrupted elastic fibers. Organ cultures of aortic explants from rabbits with or without pancreatic elastase supplementation for 5 days disclosed that there was complete loss of medial elastic fibers and increasing deposition of microfibrils, morphologically identical to elastin-associated microfibrils, around viable smooth muscle cells only in the elastase supplemented group. These observations suggest that abnormal accumulation of microfibrils in the elastic tissue is closely associated with excessive elastolysis of preformed or newly formed elastic fibers during elastic tissue remodeling. Enhanced synthesis of microfibrils may occur in response to elastolysis as a reparative phenomenon.

Actin Cytoskeleton↗

PubMed1990

Human neutrophil elastase: degradation of basement membrane components and immunolocalization in the tissue.

Human neutrophil elastase was purified to homogeneity as two isozymes named E1 and E2. The isozymes degraded Type IV collagen, laminin, fibronectin, and heparan sulfate proteoglycan similarly to each other. The degradation of such basement membrane components by elastase may assist the extravasation of neutrophils in the process of inflammation. Among the substrates tested, only type V collagen, which is susceptible to neutrophil gelatinase, was resistant to elastase. This broad substrate specificity of the enzyme may also contribute to tissue destruction at the sites of inflammation. We produced a monoclonal antibody against the purified enzyme and applied it to immunohistochemical studies. In bronchopneumonia and polyarteritis nodosa, elastase was associated with the cleaved elastic fibers, indicating that the enzyme really destroys tissue in vivo. In the exudates of rheumatoid joint, elastase was stained as diffuse fine granules. Immunohistochemical studies with the monoclonal antibody will provide a complementary way to disclose the mechanism of diseases related to neutrophil infiltration.

Antibodies, Monoclonal↗

PubMed1990

Primary lymphoma of the thyroid: a clinical, histological and immunohistochemical study of 20 cases.

Twenty cases of malignant lymphoma arising in the thyroid gland were studied clinically, histologically and immunohistochemically. Nineteen cases were non-Hodgkin's lymphoma (15 diffuse and four follicular lymphoma) and one was a plasmacytoma. Immunohistochemical analysis of the lymphomas using paraffin-embedded sections disclosed that 17 lymphomas were B-cell type and two were T-cell type. The plasmacytoma was of IgG kappa type. The large majority of the lymphomas were associated with an underlying chronic thyroiditis. The 5-year survival rate of the patients was 70%. An unfavourable diagnosis was more likely when the tumour was diffuse rather than follicular, when it was of diffuse large cell type or of immunoblastic type and when there was cervical lymph node involvement.

Adult↗

PubMed1990

Collagen synthesis by cultured arterial smooth muscle cells during spontaneous phenotypic modulation.

Quantitative and qualitative changes in collagen synthetic activity by rabbit arterial smooth muscle cells were monitored during spontaneous phenotypic modulation from days 2-15 of culture. The cultured smooth muscle cells transformed into a synthetic phenotype, reaching a maximum of 94.6% on day 4, and then gradually returned to a contractile phenotype accounting for 59.3% on day 15 of culture. The maximum collagen synthesis was found on day 7 when the cells were in early quiescent phase and showed a 91.7% synthetic phenotype. With an increasing proportion of cells in a contractile state, total collagen synthesis per cell decreased in parallel with the reduction in total protein synthesis. Synthesis of type I collagen was predominant, and the proportion of type I + III collagen was over 85% during the entire period of culture. Synthetic activity of type IV collagen, however, was relatively increased, and reached 3.8 +/- 0.4% at day 15 in comparison with 0.8 +/- 0.1% in the late logarithmic growth phase on day 4. This significant increment of type IV collagen in vitro seems to be correlated with the phenotypic modulation of cultured smooth muscle cells into a contractile phenotype.

Animals↗

PubMed1990

Arterial pressure and its variability in conscious rabbits at different ages.

Mean level and its variability of mean arterial pressure (MAP) were studied in 25 unanesthetized rabbits aged 6, 12, 18, 24 and 30 months. They were selected from the same large colony and bred with an ordinary rabbit food under a given environmental conditions. MAP in the aortic arch was continuously monitored with a catheter-transducer system for 3 hrs. Mean (M) and variance (V) of MAP for 3 hrs were not significantly altered with aging (p greater than 0.05, Kruskal-Wallis' multi-sample test). Intra-animal variations of the M and SD were small. Most of histograms of MAP for 3 hrs shows an exaggerated mode at any age. Distribution pattern of the histogram was not specific to age. These suggest that responsiveness of the baroreflex system should not be affected by aging from 6 to 30 months.

Aging↗

PubMed1989

A simple method for the Schwann cell preparation from newborn rat sciatic nerves.

We have developed a simple and relatively rapid method for obtaining a sufficient number of Schwann cells with a favorable purification ratio from newborn rat sciatic nerves. Perineurium-free nerves were torn into small fascicles of approximately 150-200 microns in diameter and explanted twice on type I collagen gel every 2 days of the culture period in order to reduce the number of contaminant fibroblasts. The last explanted tissues were fed with Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum and 100 micrograms/ml bovine pituitary extract for 10 days. More than 10 X 10(4) Schwann cells (greater than 95% purity) were obtained from newborn rat sciatic nerves.

Animals↗

PubMed1989

Altered synthesis of collagen types in cultured arterial smooth muscle cells during phenotypic modulation by dimethyl sulfoxide.

Synthetic activity of collagen types was examined in cultured arterial smooth muscle cells during modulation from synthetic to contractile phenotype by treatment with dimethyl sulfoxide (DMSO). Smooth muscle cells of rabbit thoracic aorta cultured with a 1% supplement of DMSO for 8 days (DMSO group) predominantly exhibited cellular features of the contractile type with abundant microfilaments and a distinct basement membrane. Cultured cells in the DMSO group or in controls during stationary or subconfluent phase were labeled with [3H]proline for 24 h, and the samples including the cell layer and medium were analyzed. The incorporation of proline into bacterial collagenase-digestible fractions was increased slightly in the DMSO group. Type analysis of the collagenous protein by SDS-PAGE and subsequent fluorography disclosed a markedly increased ratio of type IV/I collagen and a slightly increased type V/I collagen ratio, as compared with those of controls. A decrease of type III collagen production in DMSO-treated cells probably due to their lower cell density was also recognized. From these biochemical and morphological observations, it is suggested that increased synthesis of minor collagen types, particularly type IV collagen, is closely associated with smooth muscle phenotypic expression following DMSO treatment. Similar cellular events may occur in smooth muscle cells migrating into the intima during the process of arteriosclerosis in vivo.

Animals↗

PubMed1988

Inhibitory effect of dimethyl sulfoxide on the proliferation of cultured arterial smooth muscle cells: relationship to the cytoplasmic microtubules.

Our preliminary study has shown that dimethyl sulfoxide (DMSO) has an inhibitory effect on the proliferation of cultured arterial smooth muscle cells and promotes phenotypic modulation from the synthetic state to the contractile state. In the present study we have examined the effect of DMSO with special attention to relationship between cell growth and cytoplasmic microtubules. DMSO inhibited DNA synthesis and cell division, and concomitantly promoted microtubule assembly. Initiation of DNA synthesis and cell division of nonproliferating cells by platelet-derived growth factor (PDGF) was also inhibited in the presence of 1% DMSO. A 12-hr incubation with 10(-6) M colchicine caused disruption of microtubules; however, pretreatment with 1% DMSO for 24 hr prevented the disruption, indicating that DMSO has a stabilizing action on microtubules. A 24-hr exposure to PDGF resulted in microtubule depolymerization, while the addition of 1% DMSO prevented the depolymerization. These results suggest that DMSO inhibits DNA synthesis of cultured smooth muscle cells by stabilizing cytoplasmic microtubules.

Animals↗

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

Malignant fibrous histiocytoma of the liver: a case report and review of the literature.

A case of primary sarcomatous tumor of the liver in a 61-yr-old man is reported. The tumor, which measured 8.5 X 8 X 8 cm, was located in the right lobe of the liver and consisted of spindle cells in a storiform pattern intermingled with bizarre giant cells. Immunohistochemically, most tumor cells expressed vimentin. Cytoplasmic immunoreactivity with alpha 1-antitrypsin and lysozyme was documented in the giant cells. Ultrastructurally, cells with fibroblastic and histiocytic features were present. The morphological and immunohistochemical findings justify the conclusion that the tumor should be classified as a malignant fibrous histiocytoma. Reported cases of hepatic malignant fibrous histiocytoma were reviewed and compared with similar tumors observed in other body sites.

Histiocytoma, Benign Fibrous↗

PubMed1987

67Ga accumulation in inflammatory lesion and its mechanism: comparison with malignant tumor.

The accumulation of 67Ga in inflammatory lesions increased with time after injection of turpentine oil and reached a plateau 5 days later. At that time the uptake in the lesions was larger than any other tissue, after ten days the lesion uptake decreased. In experiments using rats which had been kept for 5 days after subcutaneous injection of turpentine oil, the accumulation of 67Ga in inflammatory lesions increased with time until six days after administration of 67Ga-citrate. It is clear from this study that 67Ga is avidly accumulated in areas where the subcutaneous tissue is infiltrated with neutrophils and macrophages, that it is not accumulated at the sites in which neutrophils are crowded, that nuclear material, mitochondria, lysosomes and microsomes do not play a major role in 67Ga accumulation in the lesion and that the main binding acid mucopolysaccharide in the lesion is a acid mucopolysaccharide which is none of the following: keratan sulfate, heparan sulfate, heparin, or chondroitin sulfate A, B or C. It is presumed that the main 67Ga binding acid mucopolysaccharide is keratan polysulfate (or other oversulfated acid mucopolysaccharides).

Animals↗

PubMed1987

Dimethyl sulfoxide induces microtubule formation in cultured arterial smooth muscle cells.

Prolonged exposure of cultured arterial smooth muscle cells to 1% dimethyl sulfoxide (DMSO) resulted in a remarkable increase in cytoplasmic microtubules and an appearance of bundle-like aggregates of microtubules associated with ribosomes (microtubule-ribosome-complex). In this complex, fine filaments of 8 to 16 nm diameter were interspersed, some of which displayed continuity with the microtubules and were studded with a single array of ribosomes. The microtubule-ribosome-complex may represent an unusual aggregate of microtubules containing incompletely polymerized forms of newly synthesized tubulin induced by prolonged effect of DMSO.

Animals↗

PubMed1987

Enhanced synthesis of type IV collagen in cultured arterial smooth muscle cells associated with phenotypic modulation by dimethyl sulfoxide.

The effect of dimethyl sulfoxide (DMSO) on synthesis of basement membrane collagen in cultured smooth muscle cells was evaluated. DMSO promoted phenotypic modulation of cells from the synthetic state to the contractile state accompanied by formation of basement membranes. By immunofluorescence using monospecific antibody against type IV collagen, type IV collagen was identified not only in the cell cytoplasms but intensely along the cell surfaces in the cultures treated with DMSO for 7 days, as compared with untreated cultures. Electron microscopic immunohistochemistry revealed the presence of type IV collagen both in the basement membrane region and in the rough endoplasmic reticulum of DMSO-treated cells. Such an enhancement of type IV collagen synthesis appears to be expressed as a result of the phenotypic changes of smooth muscle cells to the contractile state modulated by DMSO.

Animals↗

PubMed1987

Response of ligated rabbit ileal loop to Clostridium perfringens type C strains and their toxic filtrates.

The vegetative cells and toxic filtrates of Clostridium perfringens type C strains were injected into ligated rabbit ileal loops and the responses were observed. Out of 12 strains examined, 2 strains showed positive reaction in this test, when the vegetative cells were injected. One of these 2 strains was an enterotoxigenic and beta-toxigenic and the other was beta- and delta-toxigenic but not enterotoxigenic. Culture filtrates containing beta or delta toxin also showed fluid accumulation in the rabbit ileal loop. Histological findings of loops injected with culture filtrates containing beta toxin showed separated and effaced villi, hemorrhage in the mucosa, engorged vessels, inflammatory cell infiltration, and hyperplasia of the lymphoid tissue.

Animals↗

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

Systemic mastocytosis without cutaneous involvement.

An autopsy case of systemic mastocytosis without cutaneous involvement in a 76-year-old woman was described. The patient presented with general malaise, chest and epigastric discomfort, flushing of the face and progressive hepatosplenomegaly, and she terminated in hemorrhagic complications of DIC within 2 months. There was neither rash nor urticaria pigmentosa recognizable in the entire course. The diagnosis was made by the histologic identification of abnormal aggregates of mast cells in a bone marrow aspirate. These mast cell granules were chloroacetate esterase-positive, peroxidase-negative, and electronmicroscopically they were composed of fine granular materials containing variable numbers of lamellar structures. At autopsy, diffuse infiltration of the mast cells was found in the liver, spleen, bone marrow, lymph nodes, lungs, kidneys, stomach, and adrenal glands.

Aged↗