Biomedical subjects

K Shinkai

Publications and source records attributed to K Shinkai.

At least 73 records · Page 4Linked to original sources

PubMed1992

[Immunogenicity studies in experimental animals immunized with a low-molecular antigen alone and the antigen plus adjuvants].

The present studies were undertaken to clarify the immunogenicity evoked in four species, the guinea pig, rabbit, F344 rat and A/J mouse, immunized with a low-molecular antigen (TNBS) alone, TNBS plus Alum and TNBS plus FCA. Each species was divided into three groups: TNBS alone sc group, TNBS plus Alum ip groups (one and 3 times sensitization) and TNBS plus FCA sc groups (one and 3 times sensitization), and immune responses to TNBS were estimated by the assay systems of humoral immunoreactions (HA.PCA.SANA.Arthus) and cellular immunoreaction (DTH by the intracutaneous method & application method). All of the species showed significantly positive humoral immune responses in the TNBS alone sc group, the TNBS plus Alum ip groups and in the TNBS plus FCA sc groups. Nearly all of the guinea pigs and rabbits displayed positive cellular immune response (DTH by the intracutaneous method), while such immune response was never recognized in the rat groups. These results suggest that TNBS is a useful model compound as a positive control for the antigenicity tests of novel drugs.

Adjuvants, Immunologic↗

PubMed1991

Effects of methylthiodeoxyadenosine and its analogs on in vitro invasion of rat ascites hepatoma cells and methylation of their phospholipids.

The relationship between tumor invasiveness in vitro and methylation of plasma membrane phospholipids was investigated. For this purpose, two hepatoma cell lines, C1-30 and LC-AH, were used which show specific penetration to below cultured monolayers of mesothelial cells from rat mesentery and endothelial cells from calf pulmonary artery, respectively. Methylthiodeoxyadenosine (MTA) and five of its analogs, difluoro-MTA, deoxyadenosine, sinefungin, phenylthiodeoxyadenosine and fluorophenylthiodeoxyadenosine, inhibited the invasion of the tumor cells without affecting their proliferation. This inhibition was associated with reduction in the incorporation of radioactivity of [methyl-3H]methionine into cellular phosphatidylethanolamine derivatives without changes in the labelings of RNA and DNA and carboxylmethylation of protein. These compounds also decreased the membrane fluidity of the tumor cells, measured by a steady-state fluorescence polarization method. Three other MTA analogs (fluorodideoxyadenosine, fluoroazidodideoxyadenosine and fluoroaminodideoxyuridine) did not affect the invasiveness of the tumor cells or alter their phospholipid methylation or membrane fluidity at concentrations that did not inhibit proliferation. These results suggest that the decrease in invasiveness of tumor cells by MTA and its analogs is due to alterations in the phospholipid composition and fluidity of the tumor cell membranes.

Animals↗

PubMed1991

Serum requirement for in vitro invasion by tumor cells.

The effect of fetal calf serum (FCS) on in vitro invasion by rat ascites hepatoma cells (AH130) was studied by using the in vitro invasion assay. Although the coculture of the highly invasive clone (MM1) of AH130 cells and the mesothelial cell layer or endothelial cell layer in modified minimum essential medium supplemented with 10% FCS resulted in extensive penetration of the layer by the tumor cells, the omission of FCS resulted in an almost complete elimination of the in vitro invasion. The in vitro invasiveness by human small cell lung cancer cells (OC10) was also remarkably reduced by the omission of FCS from the assay medium, suggesting a requirement of serum for the in vitro tumor cell invasion. When 10% FCS was added to the medium 2 h after the tumor cell seeding in FCS-free invasion assay system, penetration by MM1 cells was observed within an hour. This rate of penetration was almost the same as that when 10% FCS was added at the time of tumor cell seeding. FCS was also required for the penetration of a mesothelial cell monolayer by MM1 cells in a defined growth medium (SFM-101), in which MM1 cells were well maintained. The invasion-inducing activity appears to be independent of the growth-stimulating activity in serum.

Animals↗

PubMed1991

[Comparison of immunological activities of guinea pig IgG1 and IgG2 antibodies to low-molecular antigen].

The present study was carried out using a low-molecular antigen to clarify which of the two IgG subclasses (IgG1 and IgG2) of guinea pigs is responsible for the immunological assay systems in ordinary antigenicity tests for the development of a novel drug, and to what extent such IgG subclass antibodies contribute to the assay systems in addition to IgM antibody. Guinea pigs were immunized with TNBS plus FCA (3 mg/body), at intervals of 10 days, 3 times in total. The anti-TNBS serum was fractionated into peak I (IgG2), peak II (IgG1) and peak IV (IgM) by DEAE-cellulose column chromatography, and the immunological activities as well as the functions of the above three peaks were estimated by HA, homologous PCA reaction, PSANA and P-Arthus. The IgM and two IgG peaks possessed immunological activities on HA and P-Arthus, and the following degree of activities was shown in both assay systems: peak II (IgG1) greater than peak IV (IgM) greater than peak I (IgG2). In the homologous PCA reaction and PSANA, immunological activities were seen only in peak II (IgG1). It is confirmed that the IgG1 subclass is a homocytotropic antibody involved in the PCA and PSANA assay systems in the case of low-molecular immunogens such as TNBS.

Anaphylaxis↗

PubMed1991

[Differences in IgG and IgE antibody responses to a low-molecular compound in inbred strains of mice].

It appears to be significant for the analytical studies of drug allergy that a comparison is made among inbred strains of mice, with different H-2 haplotypes with respect to the antibody response to low-molecular compounds. Such studies have been demonstrated by several investigators using high-molecular antigens, such as the synthetic polypeptides and natural proteins. The present experiments were undertaken, therefore, to clarify the differences in antibody responses to a low-molecular compound, TNBS in inbred strains of mice. Mice of four different strains, A/J (H-2a), C57BL/6 (H-2b), DBA/2 (H-2d) and C3H/He (H-2k) were immunized with TNBS (30 & 300 micrograms/body) plus FCA by the routes of ip or sc. Responses of IgG and IgE antibody productions were estimated by HA in serum samples treated with 2-ME and rat PCA reaction in untreated serum samples, respectively. As the results, DBA/2 (H-2d) mice showed high responses on IgE antibody production whereas C3H/He (H-2k) mice on IgG antibody production. A/J (H-2a) mice displayed high responses both on IgG and IgE antibody productions. C57BL/6 (H-2b) mice denoted low to intermediate responses both on IgG and IgE antibody productions. The above phenomenon may be interpreted by the fact that H-2a haplotype of A/J mice has a crossover on K region-E alpha subregion of H-2k and S.D regions of H-2d.

Animals↗

PubMed1990

Potentiation of invasive capacity of rat ascites hepatoma cells by adriamycin.

The effect of Adriamycin on the invasive capacity of rat ascites hepatoma cells, W1, was studied. The invasive capacity of W1 cells was estimated in vitro by counting the number of penetrated single tumor cells and tumor cell colonies formed from the penetrated cells underneath a cultured mesothelial cell monolayer (H. Akedo et al., Cancer Res., 46: 2416-2422, 1986). A considerable increment of the invasive capacity was observed when the tumor cells had been treated with 1.0 to 20.0 microM Adriamycin. This augmentation of invasive capacity of tumor cells was partially inhibited by 60 microM N-acetylcysteine, a scavenger of free radicals. On the other hand, 60 microM N-acetylcysteine did not impair the cytotoxicity of Adriamycin for W1 cells measured by an in vitro tetrazolium-based colorimetric assay for cytotoxicity.

Acetylcysteine↗

PubMed1990

Purification and characterization of tumor invasion-inhibiting factors.

Tumor invasion-inhibiting factors were purified from bovine liver using an in vitro system for estimating the tumor invasion ability. The acid-ethanol extract of liver was subjected to ultrafiltration (Amicon PM10 membrane), and the fraction corresponding to the molecular weight range below 10,000 was further fractionated by ion-exchange (DEAE-Toyopearl), gel filtration (Bio-Gel P6), and reverse-phase (C18) chromatographies. Two types of active polypeptides with molecular weights of about 5,000 and 2,000 were purified and named IIF-1 and IIF-2, respectively. Both peptides inhibited tumor invasion with half-maximum concentrations of 2-6 ng/ml in vitro. The amino acid compositions of both peptides were determined.

Amino Acids↗

PubMed1990

Anaplastic ependymoma of the spinal cord in childhood. A case report.

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cerebrospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.

Child↗

PubMed1990

[Comparative studies on delayed type hypersensitivity of low-molecular compounds and compound-protein conjugates in rabbits].

Comparative studies on immunogenicity for compounds (TNBS, CET and 4-AAP) and compound-protein conjugates (TNBS-OA, CET-OA and 4-AAP-OA) were undertaken by the assay systems of humoral reaction (HA) and cellular reaction (DTH) in rabbits. The immunogenicity of TNBS-OA was substantially different from either that of CET-OA or 4-AAP-OA in the assay system of DTH. That is, rabbits immunized with TNBS-OA plus FCA displayed positive DTH reactions to the eliciting antigen (TNBS), while such reactions were never recognized in the rabbits immunized with CET-OA plus FCA or 4-AAP-OA plus FCA to the eliciting antigen of CET or 4-AAP, respectively. The above negative reactions observed in both groups, CET-OA and 4-AAP-OA, can be explained by the ordinary interpretation that the specificity of cellular immunoreaction (DTH) is directed toward the binding part of hapten-protein conjugate. By contrast, TNBS, spread on the skin to evoke DTH, may react with epidermal proteins in vivo to form 2,4,6-trinitrophenyl (TNP)-coupled protein. Consequently, it was suggested that this TNP-coupled protein evoked the positive DTH reaction in the TNBS-OA group.

Ampyrone↗

PubMed1990

[Alternating non-cross resistant multi-drug chemotherapy against malignant lymphoma (CAMBO-VIP)--consideration of the dose intensity].

Dose intensity defined as the amount of drug used per unit time, expressed as mg/m2/week, was reported to be a significant determinant of antitumor activity of single or combined drugs in cancer chemotherapy. We formulated a 12 week high dose intensity chemotherapy (CAMBO-VIP) for the treatment of advanced non Hodgkin's lymphoma with aggressive histology. The treatment consists of weekly alternate administration of myelosuppressive and non-myelosuppressive agents. Doxorubicin was administered every other week in combination with either cyclophosphamide, etoposide or ifosfamide. On the weeks in between, non-myelosuppressive vincristine was given with either methotrexate with leucovorin rescue or bleomycin. Prednisolone was given for the first and the last 4 weeks. Dose reduction and treatment delay were kept minimal for the purpose not lowering dose intensity. As of February 1990, 32 patients (pts), median age 52, entered the study, 29 of whom completed the treatment. There were 3 incomplete cases, in which 2 were due to interruption of the treatment at 5 and 6 weeks, respectively and 1 due to a half dose given because of the old age. CR was obtained in 29 pts (90.6%). Relapse occurred in 3 (10.4%) with the median follow-up of 12 months. Two year disease-free survival (DFS) was estimated to be 76.0% for all the patients and 83.9% for CR patients. Toxicity of CAMBO-VIP was moderate with no chemotherapeutic death. Myelosuppression was severe but of short duration, requiring virtually no dose reduction. Treatment delay was 3 days, median, and maximally 28 days. The average actual dose intensity calculated from given amount of drugs and treatment duration was as high as 90% of the protocol dose intensity. Dose intensity of CAMBO-VIP protocol is highest, equaling to that of MACOP-B, among representative series of reported lymphoma protocols. A highly significant correlation was observed between 9 drug relative dose intensity and DFS of the patients treated with each protocol. Significance of dose intensity as an independent prognostic factor, however, should be determined, by a prospective carefully designed stratified randomized studies.

Aged↗

PubMed1989

Secretion of transforming growth factor-beta by human myelogenous leukemic cells and its possible role in proliferation of the leukemic cells.

Transforming growth factor (TGF)-beta activity was found in the neutral extracts of human myelogenous leukemic cells or K562 cells and the conditioned medium from K562 cell culture. BALB/c 3T3 cells grown in soft agar in the presence of TGF-beta 1 produced an activity that stimulated the growth of K562 cells. This activity was non-dialyzable, acid-stable, heat-sensitive and partially inactivated by pronase treatment. These results suggest a mutual growth reliance between the leukemic cells and fibroblasts mediated by paracrine growth factors produced by these cells.

Animals↗

PubMed1989

Inhibition of in vitro tumor cell invasion by transmethylation inhibitors.

Three inhibitors of S-adenosylmethionine-mediated transmethylation, 5'-methylthioadenosine (MTA), 2'-deoxyadenosine and sinefungin, inhibited in vitro invasion by a highly invasive clone (Cl-30) of rat ascites hepatoma cells, AH 130 (AH cells). Difluoromethylthioadenosine (DFMTA), a non-metabolizable derivative of MTA, also caused strong inhibition of invasion at concentrations that did not suppress the growth of the tumor cells. Cl-30 cells precultured in methionine-depleted medium showed decreased invasiveness. DFMTA was also effective on the invasion by fibrosarcoma, B16 melanoma and human lung carcinoma cell lines.

Adenosine↗

PubMed1989

In vitro invasion of endothelial cell monolayer by rat ascites hepatoma cells.

To study the tissue preference of invasion, we developed an assay system for the invasion of endothelial cells as a modification of the previously established assay of tumor cell invasion of mesothelial cells. Rat ascites hepatoma cells (AH 130) that had been seeded on a monolayer of cultured endothelial cells penetrated and formed tumor cell colonies under the monolayer. The penetration was time-dependent and the number of penetrated tumor cells and colonies was proportional to the number of tumor cells seeded. Comparison of the in vitro tumor cell invasion of endothelial cell monolayer with that of cultured mesothelial cell layer showed that a clone from the tumor cells (Cl-30) which was highly penetrative into the mesothelial cell layer had only limited ability to penetrate the endothelial cell layer.

Animals↗

PubMed1989

Potentiation of invasive capacity of rat ascites hepatoma cells by transforming growth factor-beta.

The in vitro invasive capacity of poorly invasive cells (W1), which were cloned from rat ascites hepatoma cells (AH 130), was potentiated dose- and time-dependently by pretreating the cells with transforming growth factor-beta (TGF-beta). This potentiation of invasive capacity was completely abolished by anti-TGF-beta antibody. When the treated cells were ip inoculated into rats, the cells extensively invaded the peritoneum, and formed penetrating tumor nodules. The effect of TGF-beta was reversed by subculturing the treated cells without TGF-beta. The potentiation of invasive capacity by TGF-beta might participate in platelet-associated enhancement of tumor cell metastasis.

Animals↗

PubMed1989

Ionophoretic activities of oligopeptide lactones and resin-glycosides in human erythrocytes.

Oligopeptide lactones (theonellapeptolides) isolated from the Okinawan marine sponge Theonella swinhoei and resin-glycosides (merremosides) from the tuber of an Indonesian medicinal plant Merremia mammosa were examined regarding their activities in transporting Na+, K+, and Ca++ ions into human erythrocytes. Each of these lactones, which had been shown, using a supported liquid membrane, to have an ionophoretic effect on the alkali metal ions, transported the ions to a different extent. The ion transporting activities of these compounds were completely lost when the macrocyclic lactone structures were cleaved by sodium methylate. Resin-glycosides with an additional branched glycosyl residue showed much greater ion transporting activities than those without it.

Erythrocytes↗

PubMed1989

Study on microleakage and gap observation of composite resin restoration.

The degree of marginal leakage in the cervical cavity restored with Clearfil Bond System F was determined using an autoradiographic technique with 45Ca isotope solution. The isotope used was 0.1 mci/ml of solution in the form of calcium chloride with pH adjusted to 7.0. In addition, the gaps between tooth and restoration were examined by SEM on replicated specimens to evaluate the degree of adaptability. 1. Although there was some degree of difference concerning the leakage between restorative methods, it was found that the leakage in the gingival margin was greater than that of occlusal margin. 2. It was found that the leakage was effectively reduced by etching on the occlusal enamel wall but no effect was observed on the gingival margin. 3. Total etching of the cavity surface was extremely effective in decreasing microleakage of the cavity. Statistically, there was a highly significant difference between the group totally etched and the groups partially etched or not etched at all. 4. The group restored without etching showed a greater increase in leakage after thermal stress was applied. 5. SEM observation suggested that the total etching was significantly effective in improving the bond between tooth surface and restorative materials. 6. The degree of gaps of each portion of the cavity increased in the following order: gingival cementum wall, cavity floor, and gingival dentine wall. No gaps, however, were observed on the occlusal wall. 7. The gaps observed on the cavity floor gradually increased from the occlusal wall to the gingival wall, and the maximum gap was usually observed near the pulpo-gingival line angle. These results indicate that total etching is far more effective in reducing the microleakage.

Acid Etching, Dental↗

PubMed1989

Gap measurement between composite fillings and cavity walls in three different cavities.

Adaptabilities of 8 kinds of resinous restorations on class 5, cervical, and root surface cavities were compared and examined. Human extracted premolars were used as experimental specimens. Restored specimens were divided into two groups: a short storage group stored for 2 weeks and a long storage group for 6 months. After thermal cycling had been undertaken with each group during storage, replicas on vertical section were made to be observed by SEM, the gaps of which were measured on the photographs. These following conclusions were obtained as a result: 1. The appearance and width of gaps between resin and cavity walls were characterized by kinds of cavities. 2. In the class 5 cavity gaps were observed on cavity floor, while almost no gaps were observed in other areas which shows fine adaptability. 3. In the cervical cavity gaps appeared in only cavity floor and on gingival wall. 4. In the root surface cavity the gaps were observed on all cavity walls, whose width was smaller on occlusal wall and especially wider on cavity floor. 5. Clearfil-F and Clearfil-FII showed fine adaptability on all cavities in general, especially on dentinal cavity wall. 6. Isopast without bonding agent and Pile-A as control showed wider gaps than the other adhesive resin. 7. Almost all the materials showed a tendency to form gaps which increased over the passage of time. The difference of width, however, varies depending on the materials; especially stable in Clearfil-F and Clearfil-FII their adhesive power showed no decrease during the experimental period.

Adhesives↗

PubMed1989

Potentiation and inhibition of tumor cell invasion by host cells and mediators.

A culture model for invasion of rat mesothelial cell layer by rat ascites hepatoma cells has been developed. By using this quantitative model, the preculture with macrophages (0.1 less than macrophage/tumor cell less than 1.0) was found to enhance both the in vitro and in vivo invasive potentials of the tumor cells. This potentiation appears to be mediated partly by oxygen radicals generated by the cocultured macrophages. The in vitro invasive capacity was also augmented by pretreating the tumor cells with TGF-beta or with activated platelets. A factor with anti-invasive potential (IIF) was extracted from rat liver. It inhibited the directed migration but not the growth of the tumor cells and was effective on their in vivo invasion and metastasis, as well.

Animals↗