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Biomedical subjects

H Tsuchiya

Publications and source records attributed to H Tsuchiya.

At least 217 records · Page 12Linked to original sources
PubMed1989

High performance liquid chromatographic analysis of time-dependent changes in urinary excretion of indoleamines following tryptophan administration.

Analytical conditions of prepurification extraction and HPLC separation were optimized for determination of urinary serotonin and tryptamine. Under optimal conditions, serotonin, tryptamine and an internal standard were extracted with 15% v/v n-propanol in diethyl ether from urine samples alkalized with a phosphate buffer (0.75 mol/L, pH 10.0), and then they were re-extracted into an HCl solution (0.1 mol/L). Purified indoleamines were simultaneously separated by reversed-phase ion-pair HPLC with native fluorescence detection. Urinary serotonin and tryptamine were selectively determined within about 45 min per sample for the whole procedure. Analytical recovery, reproducibility and detection sensitivity were satisfactory for pursuing time-dependent changes in indoleamine levels. Urinary excretion profiles of serotonin and tryptamine in subjects dosed with L-tryptophan were successfully analyzed by our method.

Adult↗
PubMed1989

Immunohistochemical analysis of mesocolic lymph node cells in human colorectal cancer.

Localization of lymphocyte subsets and macrophages in the mesocolic lymph node of the colorectal cancer and their distribution among the paracolic, intermediate, and main nodes were studied quantitatively by means of immunohistochemical staining with monoclonal antibodies. In all of the three lymph node groups, in the paracortex, helper/inducer T cells were more numerous than suppressor/cytotoxic T cells. The number of whole T cells in the paracortex diminished with increasing proximity to the primary tumor. In the three lymph node groups, no significant difference was found regarding the ratio of the cell number among suppressor/cytotoxic T cells, natural killer cells, and macrophages. Lymphocytes in the paracortex of lymph node had a positive correlation to lymphocytes in the peritumoral stroma and intratumoral fields. These data neither suggest the presence of a powerful immunological reaction in the mesocolic lymph node nor support the concept of conservation of uninvolved regional lymph nodes in the surgery of the colorectal cancer.

Adenocarcinoma↗
PubMed1989

Intermediate results and functional evaluation of limb-salvage surgery for osteosarcoma: an intergroup study in Japan.

This is a 2-7-year follow-up report by 21 institutes in Japan concerning limb-salvage surgery for osteosarcoma. Between 1980 and 1985, 248 patients with osteosarcoma were treated, and 105 patients had limb-salvage surgery. The percentage of cases treated by limb-salvage surgery increased with each year. The cumulative survival rate was 71% at 5 years in the limb-salvage group, and in the amputation group it was 46%; this indicates that cases for limb-salvage patients, tumor resection was classified this procedure. In limb-salvage patients, tumor resection was classified according to the surgical margin as intralesional excision, marginal excision, wide-with-marginal resection, wide resection, and radical resection. Wide resection was performed in most cases as the method of choice. Local recurrence was seen in 13 cases (12%). The overall functional evaluations by Enneking's system showed that the number of results rated excellent or good was relatively high in the early follow-up period, but this decreased later on, and cases rated fair or poor increased as the years passed. This was mainly due to postsurgical complications (44 cases). We identify a few problems in the functional evaluation system used now and suggest a reform of the system, so that physical and mental factors would be evaluated separately.

Adolescent↗
PubMed1989

Effects of Tween 80 and sodium fluoride on extracellular glucosyltransferase production and membrane lipids of Streptococcus mutans.

1. Both Tween 80 and sodium fluoride significantly enhanced total extracellular glucosyltransferase activities of Streptococcus mutans. 2. Water-insoluble and water-soluble glucan formation were uniformly increased by Tween 80, whereas fluoride stimulated only water-soluble glucan formation. 3. Elevated glucan formation was due to an increase in enzymes secreted from bacterial cells. 4. Fatty acid composition and phospholipid content in bacterial membrane were changed by Tween 80, although sodium fluoride scarcely showed these changes. 5. Comparative results suggest that modulation of membrane lipids participates in mutansucrase production but not in dextransucrase production of S. mutans.

Glucosyltransferases↗
PubMed1989

High-performance liquid chromatographic estimation of eluates from denture base polymers.

A quantitative analytical method using high-performance liquid chromatography is developed to estimate elution profiles of dental acrylic polymers used for denture bases. The method is applied to elution studies in distilled water of resins polymerized by different representative methods. Elution properties or 'leachabilities' vary depending on polymerization conditions. Methyl methacrylate, methacrylic acid and benzoic acid are eluted from autopolymerized resins at the highest eluate concentrations and are followed by heat- and microwave-polymerized resins. These results appear to be comparable to residual amounts of the eluates in resins and their cytotoxic potencies reported.

Acrylic Resins↗
PubMed1989

Pediatric total colonoscopy.

One hundred fifty-one total colonoscopies were performed in 105 children ranging from 1 month to 15 years of age. The cecum was reached successfully in 136 examinations without complications, generally within 30 minutes. Our major indications for total colonoscopy were abnormal findings in a contrast enema, undiagnosed rectal bleeding, and possible organic lesion causing intussusception. All procedures were performed using sedation only. The pediatric gastroscope was employed for total colonoscopy on infants less than 6 years of age; the cecum was reached successfully in 98 of 106 procedures with this instrument. Our total colonoscopy series contributed to the diagnosis of various disorders in 86 children and of normality in the 19 remaining children. The results suggest that, if performed with proper precautions and techniques, total colonoscopy is a safe and useful procedure with which to examine the entire colon of infants and children.

Adolescent↗
PubMed1989

Antimicrobial susceptibilities of Eubacterium, Peptostreptococcus, and Bacteroides isolated from root canals of teeth with periapical pathosis.

Eubacterium, Peptostreptococcus, and Bacteroides were isolated in high frequency from root canals with acute periapical inflammation. The antimicrobial susceptibilities of these strains were studied by determining minimum inhibitory concentrations of different agents. Although all three kinds of isolates were susceptible to penicillins, the isolates other than black-pigmented Bacteroides were less susceptible to cephems, tetracyclines, and macrorides with several resistant strains. All strains were uniformly resistant to aminoglycosides. Some differences in susceptibilities were observed among species of Eubacterium and Peptostreptococcus, while penicillins were effective for both species. Black-pigmented Bacteroides showed good susceptibilities to all agents except for aminoglycosides. The susceptibility of Bacteroides gingivalis was superior to that of Bacteroides intermedius. There were many resistant strains in non-black-pigmented but not in black-pigmented Bacteroides isolates. Penicillins were the most effective for Eubacterium, Peptostreptococcus, and Bacteroides, indicating that penicillins are suitable for treatment of root canals with acute apical periodontitis.

Aminoglycosides↗
PubMed1989

Growth inhibition and differentiation of murine melanoma B16-BL6 cells caused by the combination of cisplatin and caffeine.

We preliminarily investigated the combined effects of cisplatin and caffeine on murine melanoma B16-BL6 cells in vitro. When caffeine was added before or simultaneously with cisplatin, there was little growth inhibition. The addition of 2.0 mM caffeine after 1 h of exposure to cisplatin inhibited growth and induced cell differentiation. This treatment resulted in fewer cells, and the numbers of melanosomes and mitochondria and the amount of Golgi's complex and endoplasmic reticulum were increased. DNA histograms obtained by flow cytometry showed that cells treated with cisplatin alone accumulated in the G2/M phase, with a partial G2 block. The addition of 2.0 mM caffeine after 1 h of treatment with cisplatin reduced this block. Caffeine caused murine melanoma B16-BL6 cells treated with cisplatin to differentiate, and this inhibited growth.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Caffeine enhancement of the effect of anticancer agents on human sarcoma cells.

It is necessary to find modifiers which enhance the effects of known anticancer agents in order to improve both survival rate and local curability of patients with high-grade sarcomas. In this study, the effect of anticancer agents combined with caffeine was examined on cultured sarcoma cells and fresh human sarcoma specimens, utilizing the human tumor clonogenic assay technique. The combination of cisplatin and caffeine showed a synergistic inhibition of the growth of two strains of cultured sarcoma cells tested, and 14 of 18 fresh human sarcoma specimens (77.8%). This synergistic effect of caffeine was also observed with cyclophosphamide (44.8%), mitomycin C (44.8%) and adriamycin (27.8%). The combination of vincristine or methotrexate with caffeine, however, did not exhibit a synergistic effect. Caffeine, therefore, enhanced the effect of four cytotoxic DNA damaging agents. No antagonistic effects were seen in our series. This study suggests that caffeine may be useful in enhancing the tumoricidal effect of anticancer drugs, especially DNA-damaging agents, and possibly may aid in overcoming natural drug resistance.

Antineoplastic Agents↗
PubMed1989

[Angiotensin II-induced hypertension chemotherapy of bone and soft-tissue sarcomas].

We treated 14 patients with high grade sarcomas by angiotensin II-induced hypertension chemotherapy. The chemotherapy protocol described by Rosen was selected according to histological classification of sarcomas (small cell sarcoma, spindle cell sarcoma, pleomorphic sarcoma). The level of angiotensin-induced hypertension was one and half times as high as blood pressure at rest. Induced hypertension was maintained for 30-60 minutes. In three cases of 5 primary osteosarcomas, induced hypertension resulted in the increase of tumor stain and/or vascularity angiographically, and chemotherapeutic effects were CR or PR. The six cases with soft-tissue sarcomas were 2 cases each of CR, PR, and NC. The decrease of relative tumor blood flow under the condition of angiotensin II-induced hypertension was detected in 5 cases of 6 soft-tissue sarcomas by 133Xe clearance method. In the case of rhabdomyosarcoma, the decrease of tumor stain and vascularity by induced hypertension was observed on angiogram. As the side effects accompanying induced hypertension, nausea and chest oppression were noted in 2 cases, respectively. In this study it was suggested that angiotensin II-induced hypertension chemotherapy was effective for osteosarcoma, but that it might be ineffective for soft-tissue sarcomas.

Adolescent↗
PubMed1989

In vivo plaque formation on implant materials.

Plaque formation was studied in vivo by setting different implant materials on gingiva. The number of adhering viable bacteria depended on material surface properties 4 hours after setting, but not 48 hours after setting. The formation of pellicle-like thin layers and subsequent covering by lamellarly formed plaque were observed on the surfaces of all materials. Streptococcus species were predominant at the 4-hour setting time and anaerobes increased at the 48-hour setting time; this was common to all materials. The results indicate that surface properties of the implants influence early bacterial adherence, but do not influence bacterial flora or plaque maturation.

Adult↗
PubMed1989

[Flow cytometric analysis of oncogene products].

Flow cytometry (FCM) of oncogene products which opens new avenues of cell biological investigation of human neoplasia is being reviewed. Using H-ras p21/DNA dual FCM, patients with DNA-aneuploid multiple myeloma (MM) were examined. The patients whose MM cells expressed high level of H-ras p21 had poor prognosis. Specificity of this assay was appraised extensively. It is not likely that H-ras p21 expressed in MM is of oncogenic form since point mutation of H-ras gene was not reported in B cell chronic lymphocytic leukemia which is closely located to MM in B lymphocyte differentiation lineage. High expression of H-ras p21 in MM seems to be related to cell proliferation and/or differentiation. H-ras p21/DNA dual FCM is applicable to analyse the pathophysiology of tumor cells. FCM analyses of other oncogene products and proteins related to cell proliferation, c-myc, p53 and Ki-67, were also described. Multiparameter FCM analysis is quite suited to examine expression of these proteins in situ.

DNA, Neoplasm↗
PubMed1989

[DNA repair and drug resistance: enhancement of the effects of anticancer agents by DNA repair inhibitors].

Recently, it has been revealed that anticancer effects are increased by the inhibition of DNA repair of cancer cells. Methylxanthine is the drug which block DNA repair. In this study we discussed the combined effects of CDDP and caffeine or pentoxifylline using human osteosarcoma cells (OST strain). When 2 mM caffeine was added before 1 hr exposure of CDDP or caffeine and CDDP was added simultaneously for 1 hr, no synergistic effect was shown. On the other hand, marked synergistic growth inhibition was observed when caffeine or pentoxifylline was added continuously after 1 hr exposure of CDDP. The addition of caffeine from 24 hr to 48 hr after 1 hr exposure of CDDP also showed synergistic effects as the doubling time of OST cells was about 30 hrs. Further more we treated three patients with advanced osteosarcomas by the combination of CDDP, ADM, and caffeine (p.o.) or that of CDDP and caffeine. A nine-year-old boy with multicentric osteosarcoma treated by the combination of CDDP, ADM, and caffeine showed partial response, and caffeine did not increase the side effects of anticancer agents. Hence the study on overcoming drug resistance by the inhibition of DNA repair will be promising.

Adolescent↗
PubMed1989

Overall results of adjuvant chemotherapy and a chemosensitivity test for osteosarcoma.

Among 59 patients with long bone osteosarcoma without metastases at first diagnosis, the five-year cumulative survival rate was 51.7% following surgery and chemotherapy, and 14.4% in an historical control group. Preoperative combination chemotherapy with high-dose methotrexate, adriamycin, and vincristine was found to be effective in 60% (9/15) of the patients. Histopathological examination of the resected tumor indicated a necrosis rate of over 90%. Twenty tissue samples from 12 patients were tested for sensitivity to anticancer drugs using the human tumor clonogenic assay. Samples obtained by biopsy from four of five patients were found to be sensitive to methotrexate or cisplatin, as were five of six surgical specimens from primary lesions. Samples from pulmonary metastases, however, were either resistant or showed poor sensitivity to all anticancer agents tested. The predictability for methotrexate was 87.5% (7/8). Results indicate that combination chemotherapy improves patient survival. Further improvement in the overall prognosis may be achieved by using a reliable tumor sensitivity test to prepare an optimal chemotherapy program.

Adolescent↗
PubMed1989

Enhancement of cytocidal and antitumor effect of cisplatin by caffeine in human osteosarcoma.

A nontoxic dose of caffeine enhanced the cytotoxicity of cisplatin in human osteosarcoma cells (OST strain). Synergistic cytotoxicity was seen in vitro in OST cells when 2 mmol caffeine was added to a nontoxic dose of cisplatin (2 micrograms/ml). Caffeine reduced S-phase, G2/M-phase, and S-and-G2/M-phase accumulation by cisplatin on the DNA histogram, and nuclear fragmentation of tumor cells was frequently observed. Flow cytometric analysis appeared to be useful in assessing the efficacy of the combination of cisplatin and caffeine. The antitumor effect of the combination of cisplatin and caffeine was examined in OST transplanted to BALB/C athymic mice. Regression of the tumor was observed when cisplatin was given at a dose of 10 mg/kg. When 4 mg of caffeine was given once a day for three days after the administration of cisplatin, marked regression of the tumor was observed in groups treated with 5 or 10 mg/kg of cisplatin, without significant weight loss. These results indicate that caffeine enhances the antitumor effect of cisplatin on transplanted osteosarcoma in BALB/C athymic mice.

Animals↗
PubMed1989

[Combined effect of cisplatin and caffeine on murine B16-BL6 melanoma cells].

Combined effect of cisplatin and caffeine on murine B16-BL6 melanoma cells was studied. Synergistic inhibition of the cell growth was observed when caffeine (2 mM) was added continuously after one hour exposure of cisplatin. On the other hand, when caffeine was added before one hour exposure of cisplatin or one hour simultaneous exposure with cisplatin, synergistic effect was not shown. In the analysis of DNA histogram obtained from flow cytometry, S and G2/M accumulation was observed by the treatment of cisplatin and that accumulation was reduced by the combination of cisplatin and caffeine. From this findings, it was suggested that caffeine would inhibit DNA repair process. Furthermore, according to morphological studies with hematoxylin-eosin stain and Fontana-Masson stain, the addition of caffeine alone resulted in mild swelling of melanoma cells and the decrease of nuclear-cytoplasmic ratio. The combination of cisplatin and caffeine caused marked swelling of melanoma cells and remarkable increase of dendrite-like processes. Melanogenesis was also enhanced by the addition of these two drugs. Many matured melanosomes, increases of mitochondria, Golgi's apparatus and endoplasmic reticula were observed by the use of electron microscope. These findings implied that the combination of cisplatin and caffeine induced a differentiation of murine melanoma cells.

Animals↗
PubMed1989

Drug resistance and cross-sensitivity in cultured human osteosarcoma cells.

The sensitivity, cross-sensitivity, acquired resistance and restoration of sensitivity to adriamycin (ADR) in cultured human osteosarcoma (OST) cells were studied from the viewpoints of cell proliferation and cell cycle pattern by flow cytometry. OST cells resistant to ADR were produced by a treatment which consists of a 40-hour exposure to high doses of ADR and subsequent cultivation for 6 weeks and was repeated five times. ADR-resistant cells showed cross-resistance to methotrexate (MTX), and vincristine (VCR), and collateral sensitivity to cisplatin (CDDP). Treatment of the ADR-resistant cells with ADR and verapamil, a Ca-antagonist, resulted in an increased inhibition of sarcoma cell growth.

Cisplatin↗