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S Kurata

Publications and source records attributed to S Kurata.

At least 19 recordsLinked to original sources
PubMed1992

Purification and characterization of a hemocyte proteinase of Sarcophaga, possibly participating in elimination of foreign substances.

We have reported that foreign protein injected into the abdominal cavity of Sarcophaga peregrina (flesh fly) larvae is degraded in the hemolymph by a proteinase secreted by hemocytes [Suzuki, T. and Natori, S. (1985) Comp. Biochem. Physiol. 81A, 191-193]. Here we report the purification and characterization of a proteinase from larval hemocytes. This enzyme is a cysteine proteinase consisting of 26-kDa and 29-kDa subunits with similar substrate specificity to mammalian cathepsin B. This enzyme was shown to be released from hemocytes into the hemolymph of larvae following injection of sheep red blood cells into the larvae, suggesting that it participates, at least in part, in elimination of foreign substances introduced into the body cavity.

Amanitins↗
PubMed1992

Expression of heme oxygenase and its RNA in mouse liver after injection of heme and splenectomy.

Heme is known to activate the HO (heme oxygenase) gene in cultured cells, but little is known about the effect of heme on the HO gene in intact organisms. The expressions of HO and its RNA in mouse liver were measured using mouse HO cDNA and HO antibody after injection of heme or splenectomy. The antibody was prepared against a beta-galactosidase-HO hybrid protein made in Escherichia coli. The HO mRNA level increased to a maximum 15 h after heme injection. In contrast, expression of HO was maximal about 45 h after heme injection. Essentially the same results were obtained in mice after splenectomy. These results suggest that the HO gene in mouse liver was activated by the injection of heme and splenectomy.

Animals↗
PubMed1992

Purification of a 29-kDa hemocyte proteinase of Sarcophaga peregrina.

Previously, we suggested the participation of a hemocyte proteinase in the dissociation of fat body of Sarcophaga peregrina (flesh fly) at metamorphosis. We have now purified this proteinase to near homogeneity from pupal hemocytes. It is a cysteine proteinase with a molecular mass of 29 kDa and has a unique substrate specificity hydrolyzing both Suc-Leu-Leu-Val-Tyr-MCA and Z-Phe-Arg-MCA (Suc, succinyl; MCA, methylcoumaryl-7-amide; Z, carbobenzoxy), which are substrates for chymotrypsin and cathepsin B, respectively. Partial similarity was found between the amino-terminal sequence of this proteinase and that of cathepsin B, including Pro, Glu and Arg residues conserved in the papain superfamily of enzymes.

Amino Acid Sequence↗
PubMed1992

Simultaneous expression of type I procollagen mRNA and albumin in cirrhotic human liver.

The gene expression of human type I procollagen was investigated in cirrhotic human liver by using in situ hybridization with nonradioactive DNA probes. Using in situ hybridization can provide direct evidence for the cell type capable for type I collagen synthesis in tissues. T-T dimerized DNA probes were used and DNAs hybridized in situ were detected immunohistochemically using specific antibodies against T-T dimer. The data demonstrated that type I collagen is synthesized in hepatocytes and stellate cells in pseudolobules and in fibroblasts in Glissons capsules in cirrhotic human livers. We indicated hepatocytes morphologically and functionally by using immunohistochemical localization of albumin, which was used as a marker of hepatocyte, since albumin is synthesized exclusively by hepatocytes.

Adult↗
PubMed1992

The 29-kDa hemocyte proteinase dissociates fat body at metamorphosis of Sarcophaga.

Previously, we reported the purification of a 29-kDa proteinase from the pupal hemocytes of Sarcophaga peregrina (flesh fly). Antibody against this proteinase was found to inhibit dissociation of the fat body by pupal hemocytes in vitro. Moreover, the purified enzyme alone was shown to dissociate the fat body. This enzyme was found to be localized in granules of heterogeneous size in the hemocytes and to be released on their interaction with the fat body. From these results, we conclude that this 29-kDa proteinase participates in dissociation of the fat body at metamorphosis.

Animals↗
PubMed1992

Meningeal malignant melanoma in a child: immunocytological diagnosis.

A 10 year old boy, who was thought to have had a traumatic intracranial hemorrhage, was transferred to our Children's Medical Center. In spite of conservative treatment, he developed dysarthria, systemic convulsions, unconsciousness, quadriplegia, and consecutive paralysis of the cranial nerves. Magnetic resonance imaging scans demonstrated areas of increased signal intensity around the brain stem. The cerebrospinal fluid (CSF) contained a few large cells with abundant melanin-like granules, and numerous bizarre cells. The latter were considered to be malignant melanoma cells on immunocytological examination. Chemotherapy with dimethyltriazenoimidazole carboxamide (DTIC) and interferon beta (IFN-beta) was ineffective and he expired. Autopsy revealed diffuse infiltration of malignant melanoma cells into the meninges. We think that immunocytological examination of CSF is advisable for correct and rapid diagnosis.

Antibodies, Monoclonal↗
PubMed1992

[O serogroup and virulence factors of motile Aeromonas].

A total of 182 isolates of motile Aeromonas from patients with diarrhea and environmental sources was investigated for hemolytic activity to rabbit erythrocyte and cytotoxicity to HeLa 229 cell. Furthermore, the relation between O serogroup and virulence factors, which were lethal to mouse and autoagglutination, were investigated. There were many strains possessing both the hemolytic and cytotoxic activities in A. hydrophila from overseas traveller's diarrhea, suggesting that these activities were associated with intestinal pathogenecity. Although there was a clear correlation between hemolytic and cytotoxic activities in A. hydrophila from overseas traveller's diarrhea, the correlation was not found in A. hydrophila from domestic cases of diarrhea and A. sobria from overseas traveller's diarrhea. Especially, some A. hydrophila isolates from domestic case of diarrhea produced only hemolysin. These results indicated that there was a difference in specificity between the toxins accounted for hemolytic and cytotoxic activities, and more than two different toxins were developed. O serogroups 11, 34, 14, 16, and 35 in that order were the most frequent serogroups. About half of O11 and O34 strains possessed lethal activity to mouse. Autoagglutination phenomenon did not seem to be associated with the lethal activity. In O11 strains, high cytotoxic titer was more frequently found in lethal activity positive-strains than in the activity negative-strains, suggesting that cytotoxicity contributed preferentially to lethal activity to mouse. But such a correlation was not found in O34 strains, so other virulence factors than hemolysin and cytotoxin may be associated with the lethal activity.

Aeromonas↗
PubMed1992

Association between chlamydial infections and pelvic lesions.

Chlamydia trachomatis usually causes asymptomatic cervicitis, but it sometimes ascends into the uterine cavity, fallopian tubes, or peritoneal cavity, causing pelvic inflammatory disease and infertility. In this study, we examined endocervical chlamydial antigens and serum chlamydial antibodies in infertile women and laparoscopically evaluated pelvic lesions according to our pelvic scoring system. In patients testing positive for a chlamydial infection, the total pelvic score was significantly higher than in patients testing negative. When each area examined was assessed separately, however, only the tubal score was significantly higher in the chlamydia infected patients. These findings may indicate that tubal lesions are the major cause of infertility in women with chlamydial infections.

Adult↗
PubMed1991

Epidermal growth factor inhibits transcription of type I collagen genes and production of type I collagen in cultured human skin fibroblasts in the presence and absence of L-ascorbic acid 2-phosphate, a long-acting vitamin C derivative.

Recombinant human epidermal growth factor (EGF, 2-10 ng/ml) stimulated growth and production of non-collagenous proteins, but inhibited production of collagen by 60% in cultured human skin fibroblasts. Type analysis of the collagen produced indicated that inhibition of the collagen production observed was mainly a reflection of a reduction in type I collagen. The accumulation of pro alpha 1(I) and pro alpha 2(I) mRNAs and the transcriptional activity of these genes were determined in human skin fibroblasts in order to investigate site(s) of regulation of type I collagen production by human EGF in the absence and presence of L-ascorbic acid 2-phosphate (Asc 2-P), a long-acting vitamin C derivative. Human EGF (10 ng/ml) used alone reduced the steady state levels of mRNAs for pro alpha 1(I) and pro alpha 2(I) chains and transcriptional activity of these genes in vitro by 45%. Asc 2-P (0.2 mM) alone, on the other hand, raised production of type I collagen and the steady state levels of mRNAs for pro alpha 1(I) and pro alpha 2(I) collagen chains as well as stimulated transcriptional activity of these genes. Human EGF attenuated these stimulative effects of Asc 2-P. These results indicate that human EGF regulates type I collagen synthesis at the transcriptional level in cultured fibroblasts in the presence and absence of Asc 2-P. The possibility that human EGF plays a role as a regulator of type I collagen genes in vivo was discussed.

Ascorbic Acid↗
PubMed1991

Participation of a 200-kDa hemocyte membrane protein in the dissociation of the fat body at the metamorphosis of Sarcophaga.

Three monoclonal antibodies were raised against a 200-kDa protein specifically expressed on the surface of hemocytes when Sarcophaga larvae pupated. One of these antibodies significantly inhibited dissociation of the fat body in the presence of pupal hemocytes, indicating that the 200-kDa protein is essential for dissociation of the fat body by the hemocytes. When the hemocytes were treated with a mixture of the monoclonal antibodies, they were found to secrete a significant amount of chymotrypsin-like proteinase. Moreover, the number of hemocytes expressing the 200-kDa protein increased significantly after puparium formation. These results suggested that some signal is transferred to the hemocytes via the 200-kDa protein when they interact with the basement membrane of the fat body and that this induces their secretion of a chymotrypsin-like proteinase essential for decomposition of the fat body.

Animals↗
PubMed1991

Intranuclear androgen concentrations in facial skin.

The concentrations of 5 alpha-dihydrotestosterone (DHT) and testosterone were measured by radioimmunoassay (RIA) in the crude nuclear and cytoplasmic fractions of facial skin containing large sebaceous glands. The data obtained were compared with those obtained with specimens from non-target areas. The intranuclear levels of DHT and testosterone in facial skin were 0.03 +/- 0.3 pg/micrograms DNA and 0.35 +/- 0.03 pg/micrograms DNA, respectively levels in genital skin. By contrast, both androgens were below detection by RIA in non-target skin. There was no significant difference between men and women with respect to the intranuclear androgen levels in facial skin. These findings support the view that the sebaceous gland is a typical androgen target organ irrespective of sex.

Axilla↗
PubMed1991

Characterization of 5 alpha-reductase in cultured human dermal papilla cells from beard and occipital scalp hair.

In order to gain a deeper insight into the role of 5 alpha-reductase in the growth of beards in men, we studied some kinetic properties of the enzyme in cell homogenates of cultured human dermal papilla cells from beard and occipital scalp hair. When cell homogenates were incubated with [3H]-testosterone, the 5 alpha-reductase of beard dermal papilla cells exhibited an optimum activity at pH 5.5, whereas the enzyme of dermal papilla cells from occipital scalp hair showed a broad and low plateau between pH 6.0 and 9.0, without a sharp peak. The apparent Michaelis constant of 5 alpha-reductase was 3.3 x 10(-7) M in dermal papilla cells from beard and 2.4 x 10(-5) M in those cells from occipital scalp hair. The apparent Km of 5 alpha-reductase for NADPH was 2.8 x 10(-5) M and 7.6 x 10(-4) M in beard and occipital scalp hair dermal papilla cells, respectively. There were no significant differences in the substrate specificity between these two types of cells. The 5 alpha-reductase activity was recovered mainly in the nuclear fraction of beard dermal papilla cells. By contrast, it was widely distributed among the individual subcellular fractions of dermal papilla cells from occipital scalp hair. These results strongly suggest that these two kinds of dermal papilla cells have different types of 5 alpha-reductase, and that the enzyme in beard dermal papilla cells is similar in characteristics to that in the androgen target organs such as prostate.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1991

Spindle cell hemangioendothelioma: report of three cases.

Three cases of spindle cell hemangioendothelioma were studied. Two had multiple nodules and the third had a single, recurrent lesion in the dermis or subcutis of the distal extremities. The tumor initiated at the age of 3 months in one patient and at the ages of 11 or 12 years in the remaining two. Local recurrence after surgical excision was observed in all cases. Microscopically the tumors were composed of two components; cavernous blood spaces and a proliferation of spindle cells. Among these spindle cells, there were occasional epithelioid endothelial cells with intracytoplasmic lumina. Phleboliths were observed in two cases. Most of the endothelial cells lining the cavernous spaces were positive for factor VIII-associated antigen in all cases; the intracytoplasmic lumina were also positive in two cases. The spindle cells were negative for that antigen in all cases. However, they were positive for desmin in one case. Electronmicroscopically, the spindle cells resembled primitive mesenchymal cells.

Adolescent↗
PubMed1991

Recurrent malignant fibrous histiocytoma with expression of cytokeratin.

A case of locally recurrent malignant fibrous histiocytoma was documented in a 70-year-old man. He first noticed a subcutaneous nodule forty years previously. The tumor was surgically removed four times during the last four years with local recurrence on every occasion. In the recurrent tumors, the tumor cells almost completely replaced the whole dermis and invaded skeletal muscles. They were composed of pleomorphic spindle cells arranged in a storiform pattern and bizarre histiocytic cells, which were present principally in the deeper portions of the tumor. Both types of tumor cells showed marked nuclear atypicality. In the primary tumor, surrounding a large necrotic area, spindle-shaped cells were arranged in a storiform pattern. These tumor cells exhibited only mild nuclear atypia. The recurrent tumor was strongly positive for vimentin and alpha-1-antichymotrypsin. Most tumor cells were also weakly positive for KL1, a monoclonal antibody for keratin. A Western-blot analysis revealed the presence of two bands (62 and 69 Kd) reacting with KL1 in the fractions which were obtained from the tumor according to the method for keratin extraction.

Aged↗