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Biomedical subjects

S Kurata

Publications and source records attributed to S Kurata.

At least 109 records · Page 6Linked to original sources

Chemical agents and peptides affect hair growth.

During the past decade we have examined both the therapeutic and the prophylactic effects of several agents on the macaque model of androgenetic alopecia. Minoxidil and diazoxide, potent hypotensive agents acting as peripheral vasodilators, are known to have a hypertrichotic side effect. Topical use of both agents induced significant hair regrowth in the bald scalps of macaques. The application of a steroid 5 alpha-reductase inhibitor (4MA) in non-bald preadolescent macaques has prevented baldness, whereas controls developed it during 2 years of treatment. The effects of hair growth were determined by 1) phototrichogram, 2) folliculogram (micro-morphometric analysis), and 3) the rate of DNA synthesis in the follicular cells. These effects were essentially a stimulation of the follicular cell proliferation, resulting in an enlargement of the anagen follicles from vellus to terminal type (therapy) or a maintenance of the prebald terminal follicles (prevention). A copper binding peptide (PC1031) had the effect of follicular enlargement on the back skin of fuzzy rats, covering the vellus follicles; the effect was similar to that of topical minoxidil. Analyzing the quantitative sequences of follicular size and cyclic phases, we speculate on the effect of agents on follicular growth. We also discuss the triggering mechanism of androgen in the follicular epithelial-mesenchymal (dermal papilla) interaction.

Animals↗

Relationship between the prognosis of conception and the location of pelvic involvement in endometriosis: significance of the TOP (tube, ovary, peritoneum) classification.

To determine the main factors that affect the prognosis for conception in endometriosis-associated infertility, 99 infertile patients with laparoscopically confirmed endometriosis were classified according to the new TOP classification, which we have developed to evaluate the severity of endometriosis by site, i.e., fallopian tubes (T), ovaries (O) and the peritoneum (P). According to the TOP classification, a negative correlation between the pregnancy rate after treatment and the severity of lesions was noted in case of tubal and peritoneal involvement, but not when the ovaries were involved. If there was no tubal involvement or only unilateral tubal involvement, high pregnancy rates were achieved for patients with ovarian endometrioma (87%) and for those with partial or complete posterior cul-de-sac obliteration (83%). The results suggest that for endometriosis-associated infertility, the treatment modality should be selected according to the severity of tubal involvement, which is considered to contribute to infertility more than ovarian or peritoneal lesions.

Adult↗

[Subcutaneous abscess formation in the mice inoculated intragastrically with Bacteroides fragilis].

Bacteroides fragilis when inoculated intragastrically induced abscess formation in the mice of which the intestinal microbial flora had been disturbed by the prior intake of streptomycin and erythromycin in their drinking water. The lesion usually developed at the left axillary lymph node one week after inoculation and persisted for at least two months. Without the antibiotic treatment, B. fragilis did not induce such abscess formation. Although B. fragilis was isolated from blood after inoculation, intravenous administration of B. fragilis into mice did not induce the abscess formation. Therefore, B. fragilis inoculated did not appear to spread from the intestine to the distant locus via the bloodstream. The number of B. fragilis in the mesenteric lymph nodes reached 10(5) colony-forming units per lymph node 6 h after oral administration and remained unchanged over a 24-h period of infection. These results suggest that the lymphatic dissemination of B. fragilis accounts for the abscess formation at the left axillary lymph node.

Abscess↗

Effect of silane coupling agents with a bisfunctional hydrolyzable group.

Improvement of the siloxane layer on minerals by using a bisfunctional silane, such as 1,6-bis(trichlorosilyl) hexane and 1,8 bis(trichlorosilyl)octane, and the effects on adhesion of methacrylic resin to glass plates treated with the silanes were studied. The tensile bond strength of the resin to the glass plate treated with bisfunctional silane alone was high (about 20MPa) in spite of the fact that the molecule contains no double bonds. Furthermore, a mixture of bisfunctional silane and 3-methacryloxypropyltrichlorosilane showed an excellent effect for tensile bond strength and water-resistance. Based on the results, it is suggested that the better water resistant adhesion of the mixed silane depends on the higher degree of crosslinking in the siloxane phase and on the formation of an interpenetrating polymer network between the siloxane layer and the matrix resin.

Adhesiveness↗

A basic study of a new adhesive lining cement applied emulsion of hydrophobic polymer.

To diminish the effect of water on the adhesive durability of lining cement, an experimental lining cement using a hydrophobic polymer as the cement liquid was studied. The polymers were styrene-butadien-alkyl acrylate copolymer (SBA copolymer) and carboxylated styrene-butadien-alkyl acrylate copolymer (CSBA copolymer) and were used as aqueous emulsions. The cement powder consisted of alkaline silicate and calcium disilicate. The pH values of the immersion water of the cement prepared from emulsion of SBA copolymer (SBA cement) was almost the same as that of calcium hydroxide cement. The compressive and diametral tensile strengths of SBA cement gradually increased over time in water. The bond strengths of cement prepared from the CSBA copolymer emulsion containing five percent carboxyl groups by weight were superior to those of calcium hydroxide cement.

Acrylic Resins↗

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↗

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↗

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↗

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↗

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↗

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↗

[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↗

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↗