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Biomedical subjects

M Asahi

Publications and source records attributed to M Asahi.

At least 19 recordsLinked to original sources
PubMed1992

Thrombin-induced human platelet aggregation is inhibited by protein-tyrosine kinase inhibitors, ST638 and genistein.

We have investigated the involvement of protein-tyrosine kinases in thrombin-induced aggregation of human platelets, using ST638 and genistein which are known inhibitors of protein-tyrosine kinase. Preincubation of platelets with 50 microM of ST638 or 25 micrograms/ml of genistein completely blocked the platelet aggregation induced with 0.05 unit/ml of thrombin. The increase of protein-tyrosine phosphorylation bands (135-, 124-, 76-, 64-, and 60-kDa) induced with thrombin was also inhibited by these inhibitors in a dose-dependent manner. These inhibitors also blocked the platelet aggregation and protein-tyrosine phosphorylation induced with thrombin in aspirin-treated platelets. Increase of the intracellular Ca2+ concentration induced by thrombin was also inhibited by higher concentrations of genistein. These results suggest that the protein-tyrosine phosphorylation plays a certain role in platelet activation having some relation to the intracellular Ca2+ concentration.

Amino Acid Sequence↗
PubMed1992

Protein-tyrosine kinase p72syk is activated by wheat germ agglutinin in platelets.

We previously reported a molecular cloning of porcine gene syk encoding a non-receptor type 72-kDa protein-tyrosine kinase (Taniguchi et al. (1991) J. Biol. Chem. 266, 15790-15796). In this study, we have demonstrated that p72syk is expressed in porcine platelets at 0.1-0.2% of total protein and that the lectin wheat germ agglutinin induces an activation of p72syk against both auto- and exogenous-substrate-phosphorylation in porcine platelets. The activation of p72syk was abrogated by the coexistence of N-acetyl-D-glucosamine with wheat germ agglutinin. These data suggest that p72syk is a candidate of responsible protein-tyrosine kinase for platelet activation and that cell surface glycoprotein is involved in the activation of p72syk in platelets.

Acetylglucosamine↗
PubMed1992

A histopathological and ultrastructural study of eccrine porocarcinoma with special reference to its subtypes.

Five cases of eccrine porocarcinoma were studied by light and electron microscopy. Histopathologically, these could be classified into two types; the common and the giant cell type. The common type was characterized by almost uniform medium-sized cuboidal tumour cells and a formation of well-developed intracytoplasmic lumina. A broad diversity of histopathological and ultrastructural features was seen in these tumours. The tumours of the giant cell type consisted of mononuclear polygonal cells and bizarre giant cells. This type was considered to be an undifferentiated form of porocarcinoma.

Adenoma, Sweat Gland↗
PubMed1992

Glial cyst of the pineal gland with characteristic computed tomography, magnetic resonance imaging, and pathological findings: report of two cases.

Two cases of glial cyst of the pineal gland are documented. Preoperative computed tomography and magnetic resonance imaging revealed cystic lesions of the pineal region with contrast enhancement of the walls, suggesting neoplastic lesions rather than true cysts. However, the histopathological examination of the resected specimens revealed the presence of glial tissue and normal structure of pineal gland and capsule, characteristics that were consistent with those of glial cysts of the pineal gland. Headache and visual disturbance were resolved after total removal of the cysts.

Adolescent↗
PubMed1992

Sweat gland carcinoma with mucinous and infiltrating duct-like patterns.

We report a rare case of mucinous carcinoma of the skin with mammary infiltrating carcinoma-like patterns. An 82-year-old Japanese male had a gourd-shaped tumor on his scalp. Histopathologically, the posterior portion of the tumor showed small lobules of cuboidal tumor cells with no atypia floating in mucinous lakes. In the anterior portion, there were solid lobules, cords, and strands of anaplastic tumor cells infiltrating into the surrounding stroma. Enzyme- and immunohistochemistry and electron microscopy confirmed the eccrine origin of this tumor. It is suggested that mucinous carcinoma of the skin can occur in association with diverse histological patterns, analogous to mucinous carcinoma of the breast.

Acid Phosphatase↗
PubMed1991

Identification of the phosphorylation sites of H2B histone by a catalytic fragment of p72syk from porcine spleen.

Phosphorylated sites of calf thymus H2B histone were investigated with a catalytic fragment of 72 kDa protein-tyrosine kinase (p72syk). Three of five tyrosine residues in H2B histone can be phosphorylated by this kinase. In this analysis, H2B histone was thoroughly phosphorylated in vitro with [gamma-32P]ATP and the kinase, and then digested with a lysylendopeptidase. The resulting radioactive phosphopeptides were separated by a reverse-phase column on high performance liquid chromatography. Subsequent sequential Edman degradation of the purified phosphopeptides revealed that 40Y, 83Y and 121Y were phosphorylated. 121Y is the major phosphorylated residue in H2B histone. No phosphorylation was detected in 37Y and 42Y. Although the consensus sequence was not defined from these analyses, our data suggest that higher-order structure(s) in addition to primary one may participate in recognition of H2B histone by this protein kinase.

Amino Acid Sequence↗
PubMed1991

Possible endogenous substrate proteins for cytosolic protein-tyrosine kinase from porcine spleen.

1. Endogenous phosphate acceptor proteins by cytosolic protein-tyrosine kinase from porcine spleen (CPTK-40) were studied using subcellular fractions of porcine spleen and supernatant fraction of rat various tissues. 2. At least 13 phosphate acceptor proteins ranging from 94 to 26 kDa were observed in all but mitochondrial subcellular fractions. 3. Among the supernatant fraction of rat tissues, brain, testis and spleen contained many phosphate acceptor proteins. 4. The most heavily phosphorylated band of around 55 kDa which was commonly recognized among various tissues was confirmed as tubulin by the immunoreactivity with anti-tubulin antibody. 5. The results obtained in this paper indicate that CPTK-40 has the potential to catalyze the phosphorylation of numerous endogenous proteins including tubulin.

Animals↗
PubMed1991

Medusa head-like granules in squamous cell carcinoma with differentiation toward a hair follicle structure.

A case of squamous cell carcinoma (SCC) with regional lymph node metastasis in a 69-year-old Japanese man is reported. The tumor was characterized by the proliferation of peripheral basaloid, inner squamoid, and glycogen-rich cells, the presence of trichilemmal keratinization, and the presence of ladder-like, membrane-coating granules. These findings suggested that this tumor differentiates toward a hair-follicle structure. The most interesting feature of this tumor was the presence of medusa head-like granules in the cytoplasm of the clear squamoid cells adjacent to the keratinized cells. We have been unable to find any other studies of these granules in squamous cell carcinoma.

Aged↗
PubMed1991

Invasion and survival of Fusarium solani in the dexamethasone-treated cornea of rabbits.

Electron microscopic observations, as well as in vitro experiments, on experimental Fusarium solani keratitis of rabbits were performed to study the mode of fungal invasion into the corneal stroma, the interactions between F. solani and inflammatory cells under the influence of topical dexamethasone (DXM) treatment, and the survival mechanism of the fungi in the DXM-treated cornea. Electron microscopy showed that, while the fungus invaded into the corneal stroma, digestion of collagen fibrils occurred around the hyphae, where amorphous material was often noted. In DXM-nontreated cornea, the fungal hyphae were entrapped by pseudopodia of the neutrophils and destruction of the hyphae was noted on day 3 of infection, most hyphae having disappeared by day 7. In the DXM-treated cornea, however, neutrophils could not ingest and destroy the hyphae. In qualitative nitroblue tetrazolium (NBT)-reduction tests using rabbit peripheral blood neutrophils, DXM significantly suppressed the rate of NBT-reduction and the rate of adherence to the fungal microconidia. In the DXM-treated corneal lesions, a considerable increase in both number and size of fungal peroxisomes was noted. Furthermore, the hyphae, surrounded by neutrophils, showed double or triple cell wall formation or sometimes a hypha-in-hypha structure. Similar hypha-in-hypha structures were also observed when the organisms were treated in vitro with a fungistatic concentration of H2O2. We suggest that this special structure is a protective device produced for the survival of F. solani when subject to neutrophil attack in the DXM-treated cornea.

Animals↗
PubMed1991

[Dermatological findings in the annual examination of the patients with Yusho in 1989-1990].

We reported the skin symptoms of the patients with Yusho in the 1989 and 1990 annual examinations. We also studied the alteration of the skin symptoms in 33 patients followed up for 14 years (1977-1990). Most of these patients showed obvious improvement in their skin symptoms during 12 years (1977-1988). However, a remarkable improvement was not observed in recent 3 years and approximately 40% of the patients still had comedones and/or acneiform eruptions.

Female↗
PubMed1979

[Clinical application of NK 631, a new derivative of bleomycin (author's transl)].

It is impossible to accurately evaluate NK 631 as an anticancer agent from the findings only in the 7 cases; hence, the following is no more than the author's impression about the drug. However, NK 631 appeared to exert a similar anticancer effect to the currently available bleomycin. In other words, the drug will completely cure or greatly improve the early cases of squamous cell carcinoma, and bring about a transient regression in the advanced cases. The response of malignant lymphoma to this drug varied from case to case; in any event, it is impossible to anticipate a complete cure in this malignancy by single NK 631 therapy but by multiple combination chemotherapy, e.g., BEMP therapy. The adverse reactions to NK 631 that were observed included pulmonary fibrosis, though only in 1 case; hence, no conclusive opinion should be given herein about it pulmonary toxicity in comparison with the pulmonary toxicity of bleomycin. It remains a theme of the future statistic studies in a large number of cases. The other adverse reactions were anorexia and mild alopecia in some of the cases, which were similar to those to bleomycin. Pigmentation also occurred in one of the cases, but the author was impressed that this reaction was less likely to occur with NK 631.

Aged↗
PubMed1978

[Giant basilar aneurysm--a case report (author's transl)].

A case of a giant aneurysm arising from the basilar artery is presented. The patient a 41--year-old female, had recent memory disturbance, miscalculations and hemiparesis on admission. Vertebral angiograms displayed a giant aneurysm measuring approximately 66 mm in diameter arising from the basilar artery, a tortuous vertebral artery, an extremely dilated basilar artery and an agenesis of the left carotid artery. Due to the enormous size of the aneurysm and its location in the deep intracranial portion, radical surgery was abandoned. Six months following her discharge, she died. At autopsy, the giant aneurysm arising from the top of the basilar artery was found, existing just beneath the third ventricle and extending to the left basal ganglia. The lateral ventricle, the third ventricle and the Sylvian fissure were filled by hematoma resulting from the rupture of the aneurysm. It is possible that this giant aneurysm could be considered a vascular anomaly, and hence be distinguished from saccular aneurysms.

Adult↗
PubMed1978

Essential IgG cryoglobulinemia with purpura and cold urticaria.

An 80-year-old woman with essential cryoglobulinemia developed recurrent, widespread, purpuric lesions with superficial skin ulcers and cold urticaria. No disorders of other organ systems were recognized. Attempts to transfer the cold sensitivity passively by serum and isolated cryoprecipitate of the patient were successful. Immunochemical studies showed that the cryoglobulin was composed of IgG only. It was suggested that the cryoprecipitate might not be due to immune complex formation in this case.

Adrenal Cortex Hormones↗