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Biomedical subjects

H Taniguchi

Publications and source records attributed to H Taniguchi.

At least 631 records · Page 35Linked to original sources
PubMed1987

[Antitumor activity of platinum analogs against human ovarian tumors heterotransplanted into nude mice].

The chemotherapeutic effects of CDDP, CBDCA and CHIP on human ovarian cancers heterotransplanted into nude mice (mucinous cystadenocarcinoma OVA-1, poorly differentiated adenocarcinoma OVA-2, endometrioid adenocarcinoma OVA-3, serous cystadenocarcinoma OVA-4, and three yolk sac tumors YST-1, YST-2, YST-3) were examined. OVA-1 did not respond to CDDP, although it responded well to CBDCA and CHIP. OVA-2 responded well to all these platinum analogs. OVA-3 responded well to CDDP, but did not respond to CBDCA or CHIP. OVA-4 responded well to CDDP and CBDCA, but did not respond to CHIP. Tumors YST-2 and YST-3 exhibited broadly comparable sensitivity to CDDP and the two other analogs, and YST-1 was substantially more sensitive to CDDP than to CBDCA or CHIP. The results indicated the necessity of selection of platinum analogs according to the histological types of tumor for the effective treatment of ovarian cancer.

Animals↗
PubMed1987

Cyclosporin A stimulates hair growth in nude mice.

When cyclosporin A (CyA) at doses of 10 and 100 mg/kg body weight/day was given for 14 days to six-week-old female and male nude mice, the length of the hair of CyA-treated mice began to increase from day 7 of the treatment at both doses. There was no hair growth in the control mice, which were given only olive oil. The hair length of CyA-treated mice was 3 to 4 times longer than that of control mice. CyA at both doses induced hair growth to the same extent. There was no difference in the hair growth between the male and female mice. The growth of hair was apparent on the neck, back, and hip. However, no hair growth was observed in the abdominal region. The hair length of the CyA-treated mice decreased after cessation of the treatment, and returned to the level of the control mice on day 14 after the end of the treatment. Microscopic examination revealed that there was no difference in the number of hair follicles between the control and the CyA treated mice.

Animals↗
PubMed1987

[Fundamental studies on the properties of a new adriamycin delivery system involving adsorption to activated carbon particles].

Adriamycin (ADM) was absorbed onto fine particles of activated charcoal. The characteristics of this newly developed drug delivery system were then examined in vitro. Eighty micrograms of ADM was released from the charcoal reversibly, and the biological activity of ADM released from the charcoal was retained perfectly. The ADM was released so slowly and continuously that the concentration of ADM around the charcoal particles remained high for a long time. Such characteristics suggested that ADM-CH may be available for the treatment of peritonitis carcinomatosa and lymph node metastases.

Adsorption↗
PubMed1986

Phosphorylation of microsome-bound cytochrome P-450 LM2.

The phosphorylation of a microsomal protein of rabbit liver by catalytic subunit of cyclic AMP-dependent protein kinase was shown, and the protein was identified as cytochrome P-450 LM2 on basis of comparative peptide-mapping. Acid hydrolysis of microsome-bound phosphorylated cytochrome P-450 revealed that phosphorylation occurred exclusively on serine residues. This serine residue was identified as the same residue phosphorylated in purified, soluble P-450, that is, serine in position 128.

Animals↗
PubMed1986

Comparison of the nucleotide sequences of the genes for the thermostable direct hemolysin and the thermolabile hemolysin from Vibrio parahaemolyticus.

The nucleotide sequences of genes encoding the thermostable direct (TSD) hemolysin and the thermolabile (TL) hemolysin of Vibrio parahaemolyticus were determined. From the nucleotide sequence of the TSD hemolysin gene, it was revealed that the preprotein and the mature protein consisted of 189 amino acids and 165 amino acids, and that the molecular weights were 21.1 kDa or 18.5 kDa, respectively. Our data regarding TSD hemolysin were in complete agreement with previously published data. From the nucleotide sequence of the TL hemolysin gene, it was revealed that the preprotein and the mature protein consisted of 418 amino acids and 398 amino acids, and that the molecular weights were 47.5 kDa and 45.3 kDa, respectively. The GC content of the TSD hemolysin gene was 35.6%, while that of the TL hemolysin gene was 47.6% which is almost the same as that of V. parahaemolyticus genome. Maxicell analysis revealed that the molecular weights of the proteins encoded by the TSD hemolysin gene were 22.0 and 19.5 kDa, and that of the protein encoded by the TL hemolysin gene was 45.5 kDa, and that the promoters of these two hemolysin genes of V. parahaemolyticus were functional in Escherichia coli.

Amino Acid Sequence↗
PubMed1986

Effect of complement depletion by cobra venom factor on fowlpox virus infection in chickens and chicken embryos.

The course of infection with an attenuated strain of fowlpox virus (FPV), which is known to induce antibody-independent activation of complement via the alternative pathway, was investigated in 1- to 3-day-old chickens and 14-day-old chicken embryos by treatment with cobra venom factor (CVF). CVF was found to inhibit complement activity transiently via the alternative pathway but not via the classical pathway. In chickens treated with CVF, virus growth in the skin was enhanced, and pock lesions tended to disseminate, leading to fatal infection in some birds. Histologically, an acute inflammation at an early stage of infection (within 3 days) was inhibited, and virus content in the pock lesion was increased. In chicken embryos with immature immune capacities, CVF treatment caused changes in pock morphology from clear pocks to diffuse ones, an increase in virus content in the pock, and inhibition of cell infiltration. Thus, FPV infection was aggravated in both CVF-treated chickens and chicken embryos. These results are discussed in relation to roles of complement in the elimination of virus at an early stage of FPV infection.

Animals↗
PubMed1986

[Basic study of anti-cancer agents suspended in lipiodol].

Anti-cancer agents suspended in Lipiodol have been proved to be effective in the targeting of chemotherapy for cancer of the digestive organs. 5-FU, ADM and MMC were suspended both separately and collectively in Lipiodol. These preparations were terned FULIP, ADRLIP, MMCLIP and FAMLIP, respectively. Forty percent 5-FU was released from FULIP within 24 hours. ADM and MMC were released more slowly from ADRLIP and MMCLIP when compared with FULIP. ADM W/O type emulsion (ADM was dissolved in 60% Urographin/Lipiodol) released ADM so rapidly that 37% of the drug was detected in the water phase within 10 hours. However, the ADM W/O emulsion with Arlacel-A was much slower. From these results, it was suggested that the release speed of anti-cancer agents can be controlled by modifying the drug dosage and form. FAMLIP released 5-FU, ADM and MMC independently and the release speeds were equal to FULIP, ADRLIP and MMCLIP. It was also suggested that the biological activities of 5-FU, ADM and MMC in FAMLIP were stable in FULIP, ADRLIP and MMCLIP. It should therefore be possible to use a large amount of anti-cancer agent suspended in Lipiodol, as a combined drug cancer therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

The role of leukotriene B4 in the genesis of oxygen toxicity in the lung.

Leukotriene B4 (LTB4) is a metabolite of arachidonic acid that has potent chemotactic activity for polymorphonuclear leukocytes (PMN). Pulmonary oxygen toxicity is considered to be a good model of an acute inflammatory lung injury, and an increase in the number of PMN is found in the lungs acutely injured by hyperoxia. In order to estimate the role of LTB4 responsible for this influx of PMN, we measured the LTB4 by radioimmunoassay in lung lavages of rats exposed to hyperoxia for 60 h. We found that the level of LTB4 in lung lavages in rats exposed to hyperoxia for 60 h increased significantly compared with that in normoxic control rats. At the same time, the marked increase in the number of PMN in lung lavages and the decrease in the activity of NADPH-cytochrome c reductase in lung microsomes were also observed. The administration of AA861, a 5-lipoxygenase inhibitor, reduced not only the increase in LTB4 but also the increase in the number of PMN in lung lavages of rats exposed to hyperoxia for 60 h. Furthermore, treatment with AA861 also protected the decrease in the activity of NADPH-cytochrome c reductase. The effects of AA861 on these parameters were observed in a dose-dependent fashion. In addition, there is a good correlation between the level of LTB4 and the number of PMN in the lavage of rats exposed to hyperoxia for 60 h with or without AA861 administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Phosphatase affects microsomal monooxygenase mainly via reductase.

Treatment with alkaline phosphatase of hepatic microsomes prepared from rabbit, rat, and mouse caused a marked decrease of their specific monooxygenase activity (7-ethoxycoumarin-deethylation). This decrease occurred without a significant change in the microsomal content of cytochrome P-450, but with an equally marked decrease of NADPH-cytochrome P-450 reductase (cytochrome c reduction). Thus the phosphatase effect on monooxygenase is mainly due to the inactivation of the reductase.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1986

Inhibitory effects of tetragastrin and histamine on carcinogenesis in the small intestines of W rats by N-methyl-N'-nitro-N-nitrosoguanidine.

The effects of tetragastrin and histamine on the incidence and histology of tumors induced in the small intestine by N-methyl-N'-nitro-N-nitrosoguanidine [(MNNG) CAS: 70-25-7] were investigated in male W rats. Animals were given MNNG at 150 micrograms/ml in their drinking water for 25 weeks and then 300 micrograms tetragastrin or 4 mg histamine dihydrochloride sc per day in depot form. Administration of tetragastrin or histamine after MNNG treatment resulted in a significant increase in gastric acid secretion and a significant reduction in the incidence of tumors in the duodenum; however, only histamine decreased the incidence of tumors in the jejunum. Histologically, the tumors induced in the small intestine were mostly adenocarcinomas, and their histologic type was not affected by either tetragastrin or histamine.

Adenocarcinoma↗
PubMed1986

Effect of tetragastrin on the colonic mucosa of rats during intrarectal administration of N-methyl-N'-nitro-N-nitrosoguanidine.

The effects of the C-terminal tetrapeptide of gastrin, tetragastrin, on the colonic mucosa on Days 15 and 25 during intrarectal administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and its effects on the incidences of colonic tumors in experimental Wk 20 and 35 were investigated in Wistar rats. Administration of tetragastrin in depot form during instillation of MNNG resulted in significant decreases in the incidences of mucosal erosions, ulcerations, and atypical regenerative glandular hyperplasias in the colonic mucosa, most of these lesions being greater in the distal half of the colon. Administration of tetragastrin also significantly decreased the incidences and/or numbers of colonic tumors in Wk 20 and 35. The distribution of colonic tumors induced in Wk 20 and 35 corresponded well to those of erosions, ulcerations, and atypical regenerative glandular hyperplasias induced during the administration of MNNG. These findings suggest that the effect of tetragastrin in decreasing the incidences of erosions, ulcerations, and atypical regenerative glandular hyperplasias in the colonic mucosa during instillation of MNNG is related to its effect in reducing the development of colonic tumors.

Animals↗
PubMed1986

Mechanism of rat lung microsomal dysfunction induced by oxygen breathing in relation to the effect of alpha-tocopherol.

The toxic effect of high oxygen concentrations on the lung was investigated together with the effect of alpha-tocopherol (Juvela). Rats were exposed to 80, 60 or 40% oxygen for 2, 4 or 8 days with or without alpha-tocopherol treatment. The composition of fatty acids in microsomal phospholipids was determined by high-performance liquid chromatography. Microsomal electron transport activity and the levels of lipoperoxides in lung microsomes were determined by measuring the specific activity of NADPH (reduced nicotinamide adenine dinucleotide phosphate)-cytochrome c reductase and by spectrophotometry, respectively. Exposure to 80 or 60% oxygen induced significant decreases in the contents of arachidonic and docosahexaenoic acids, and also reduced microsomal electron transport activity. The level of lipoperoxides was elevated on the 2nd day of exposure to 80 or 60% oxygen, however, it returned to normal thereafter. On the other hand, exposure to 40% oxygen affected none of these parameters. Treatment with alpha-tocopherol prevented the changes in those fatty acids and microsomal function up to 2 days with exposure to 80% oxygen and up to 4 days with exposure to 60% oxygen. However, microsomal dysfunction and reductions of arachidonic and docosahexaenoic acids contents were observed after the 4th day of exposure to 80% oxygen or the 8th day of exposure to 60% oxygen irrespective of alpha-tocopherol administration. On the contrary, alpha-tocopherol administration prevented an elevation of the level of lipoperoxides. These results suggest that lung microsomal dysfunction induced by over 60% oxygen breathing is ascribed to the alteration of fatty acids composition in microsomal phospholipids and that alpha-tocopherol has a protective effect in the early phase.

Animals↗
PubMed1985

Major histocompatibility complex restriction fragment length polymorphisms define three diabetogenic haplotypes in BB and BBN rats.

Class I and II major histocompatibility complex (MHC) probes can be used to subdivide diabetes-prone BB rats and their BBN control strain, coderived from the same outbred colony by selection against diabetes. Class II probes (A-alpha in particular) distinguish four restriction fragment length polymorphisms (RFLP), termed 1a, 1b, 2a, and 2b, in the BBN population, only one of which (2a) is found in BB rats. The degree of class II RFLP in the population studied is RT1.B-alpha greater than or equal to RT1.B-beta greater than RT1.D-alpha greater than or equal to RT1.D-beta, suggesting that intra-class II region dynamics may be different in rats compared with mice. A class I probe (S16) absolutely distinguished BB from BBN rats, since all BB rats exhibit an RFLP pattern termed 2a0, while 2a BBN rats can be subdivided into 2a1 and 2a2 forms. Serologic evaluation has shown that 2a0, 2a1, and 2a2 rats express RT1.AuBu, 1a rats express RT1.AaDa, and 1b rats express neither RT1a nor RT1u at the loci tested. A breeding study was carried out to determine the diabetogenicity of the MHC-defined RFLP's. As expected, the BB-derived 2a0 is diabetogenic. The BBN-derived 2a1 and 2a2 RFLPs are also diabetogenic, while 1a and 1b rats do not carry MHC-linked diabetogenic genes. The MHC-linked diabetes gene acts in a functionally recessive manner, since there is a 10-fold higher incidence in homozygotes than in heterozygotes. Analysis of the RFLP patterns leads us to hypothesize that the 2a1 RFLP results from a crossover between 1a and 2a0 MHCs and that the diabetogenic MHC-linked gene is on the class II side of Qa and T1. The availability of three diabetogenic MHC haplotypes should help localize the MHC-linked diabetogenic gene of rats.

Animals↗