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H Taniguchi

Publications and source records attributed to H Taniguchi.

At least 613 records · Page 34Linked to original sources
PubMed1987

Genetic analysis of the cell binding domain region of the chicken fibronectin gene.

We have determined the nucleotide sequence of the cell binding domain region of the chicken fibronectin gene and analyzed it evolutionaly. We present here the complete nucleotide sequence of 4.3 kb HindIII/EcoRI segment from the clone lambda FC23 of the chicken fibronectin gene. There were five exons in this segment. When we lined up the amino acid of exons 28, 29 and 31, three alignments, known as the Type III repeat, appeared. Tetrapeptide, -RGDS-, called the cell binding domain, existed in the second repeat, coding exon 30. It was presumed that the Type III repeats were composed of two exons in the chicken gene, the same as in the rat and humans. We found repeatedly appearing amino-acid sequences such as -TIT- (three arrays in these Type III repeats) but also found one of the amino acids substituted in the tripeptide in these Type III repeats (seven arrays). We analyzed these repeats from the point of view of evolution. We used three of the nucleotide sequences (12-18 bp) coding such -TIT- repeats as a unit length for comparing the various homologies after dividing the coding region into 56 segments. The mutual homology of the divided segments to each one of three showed 53% on average. On the other hand, the mutual nucleotide homology of the Type III repeat was 44%. This suggested that the Type III repeat may have been developed by frequent duplication of small gene units.

Amino Acid Sequence↗
PubMed1987

Protein-protein and lipid-protein interactions in a reconstituted cytochrome P-450 dependent microsomal monooxygenase.

NADPH-cytochrome P-450 reductase and cytochrome P-450, both purified from liver microsomes of phenobarbital-treated rabbits, were incorporated into dimyristoylphosphatidylcholine vesicles. The reduction of cytochrome P-450 by NADPH in the reconstituted vesicles proceeded in a biphasic fashion, and 70-80% of the absorbance change was associated with the fast phase. The Arrhenius plot of the apparent first-order rate constant of the fast-phase reduction showed a marked discontinuity around the phase transition temperature of the synthetic phospholipid; an almost 10-fold change in rate constant was associated with this discontinuity. It was, therefore, suggested that the reduction of cytochrome P-450 by reductase in this system was a diffusion-limited reaction controlled by the viscosity of the phospholipid membrane. The Arrhenius plot of overall drug monooxygenase activity catalyzed by the reconstituted vesicles showed a break but in a different way from that observed for the reduction of cytochrome P-450. This break was accompanied only by a change of the slope of the plot but not by a change in reaction rate. This difference in the two Arrhenius plots was attributed to that in the rate-limiting step of the two reactions. NADPH-cytochrome c reductase activity of the reconstituted vesicles, an activity catalyzed by the reductase alone, and cumene hydroperoxide dependent N-methylaniline demethylation activity catalyzed by cytochrome P-450 alone did not show any break in the Arrhenius plots.

Animals↗
PubMed1987

Enhancement by vasoactive intestinal peptide of experimental carcinogenesis induced by azoxymethane in rat colon.

The effects of vasoactive intestinal peptide (VIP) on the incidence and histology of colonic tumors induced by azoxymethane (AOM) were investigated in Wistar rats. Rats were given 20 micrograms/kg body weight of VIP every other day for 12 weeks and from experimental week 3, were given 10 weekly injections of 7.4 mg/kg body weight of AOM. The administration of VIP before and during AOM treatment resulted in a significant increase in the incidence of colonic tumors in week 40. Furthermore, it caused a significant increase in the labeling index of the colonic mucosa during AOM treatment. These findings indicate that VIP enhanced the development of colonic tumors. This effect may have been related to its effect in increasing proliferation of cells in the colonic mucosa during administration of the carcinogen.

Animals↗
PubMed1987

The effects of phosphatase on the components of the cytochrome P-450-dependent microsomal monooxygenase.

Incubation of rabbit liver microsomes with alkaline phosphatase resulted in a marked decrease of NADPH-dependent monooxygenase activities. This decrease was found to be correlated with the decrease of NADPH-cytochrome c reductase activity catalyzed by NADPH-cytochrome P-450 reductase. Neither the content of cytochrome P-450, as determined from its CO difference spectrum, nor the peroxide-supported demethylase activity catalyzed by cytochrome P-450 alone was affected by the phosphatase treatment. NADH-cytochrome b5 reductase and cytochrome b5 were not affected by the phosphatase either. NADPH-cytochrome P-450 reductase purified from rabbit liver microsomes lost its NADPH-dependent cytochrome c reductase activity upon incubation with phosphatase in a way similar to that of microsome-bound reductase. Flavin analysis showed that the phosphatase treatment caused a decrease of FMN with concomitant appearance of riboflavin. Alkaline phosphatase, therefore, inactivates the reductase by attacking its FMN, and the inactivation of the reductase, in turn, leads to a decrease of the microsomal monooxygenase activities.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1987

Isoenzyme-specific phosphorylation of cytochromes P-450 and other drug metabolizing enzymes.

A series of fourteen cytochrome P-450 isoenzymes was treated with three different protein kinases and found to divide into isoenzymes phosphorylated by both the cyclic AMP-dependent kinase and the calcium-phospholipid-dependent kinase (P-450 PB 3a and PB 2e), by none of these kinases (P-450 PB 1b, MC 1b, UT 1, and thromboxane synthase), and by either the cyclic AMP-dependent kinase (P-450 LM 2, PB 2d, and PB 3b) or the calcium-phospholipid-dependent kinase (P-450 PB 1a, PB 2a, MC 1a, LM 3c, and LM 4). Other components of the monooxygenase system, cytochrome P-450 reductase, cytochrome b5, cytochrome b5 reductase as well as microsomal epoxide hydrolase, were poor substrates for the kinases employed. On the other hand, glutathione transferases 1-2 and 4-4, but not 3-3, were relatively good substrates for the calcium-phospholipid-dependent kinase.

Animals↗
PubMed1987

Enhancement by propranolol of the inhibitory effect of tetragastrin on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of combined administration of propranolol and tetragastrin on gastric acid secretion and the incidence and histological types of gastric adenocarcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in inbred Wistar rats. Prolonged administration of tetragastrin, 1 but not 0.2 mg/kg body weight in depot form after treatment with N-methyl-N'-nitro-N-nitrosoguanidine significantly reduced the incidence of adenocarcinoma of the glandular stomach. The adenocarcinomas that did develop in rats treated with the higher dose of tetragastrin had high mucin-producing activity and showed little or no typical glandular structure. A combination of propranolol (2 mg/kg) and tetragastrin (1 mg/kg) did not influence the inhibitory effect of gastrin on gastric carcinogenesis. However, concomitant administration of propranolol (2 mg/kg) and tetragastrin (0.2 mg/kg) caused a significant increase in gastric acid secretion and a reduction in the incidence of gastric carcinomas. With this treatment, the incidence of adenocarcinoma was similar to that of treatment with tetragastrin (1 mg/kg). Histological examinations showed that like the cancers in control rats, the adenocarcinomas induced in these rats were all highly differentiated.

Adenocarcinoma↗
PubMed1987

Leiomyosarcoma of the kidney: report of a patient with favorable response to doxorubicin and cisplatin suspended in a lipid contrast medium and cyclophosphamide.

A man who had unresectable leiomyosarcoma of the left kidney with skin and lung metastases was treated with intra-arterial infusion chemotherapy consisting of cisplatin and doxorubicin suspended in lipid contrast medium, lipiodol, and oral administration of cyclophosphamide. The tumor responded well to this treatment three times. He is alive and well in remission, the renal tumor decreased in size, and lung metastases became unclear more than 50 weeks after treatment was completed.

Aged↗
PubMed1987

Posttranslational modifications of the cytochrome P-450 monooxygenase system.

Two forms of enzymatic posttranslational modifications of the monooxygenase system are described: modification by phosphatase and modification by protein kinase. Phosphatase treatment of microsomes isolated from phenobarbital-pretreated rabbits and rats caused a marked decrease of monooxygenase activity which was paralleled by a comparable decrease of NADPH-cytochrome P-450 reductase activity while the second essential component of the system, cytochrome P-450, remained unaltered. Thus phosphatase attacks monooxygenase via reductase. Protein kinases showed the opposite preference; while cytochrome P-450 was phosphorylated, NADPH-cytochrome P-450 reductase was not. Thus the kinase affects monooxygenase via cytochrome P-450. The phosphorylation of cytochrome P-450 turned out to be a specific reaction observed only with certain cytochrome P-450 isoenzymes and certain protein kinases.

Animals↗
PubMed1987

Intraarterial injection of anti-tumor drugs dispersed in lipid contrast medium: a choice for initially unresectable hepatoblastoma in infants.

Intraarterial injection of anti-tumor drugs (THP-ADR, CDDP, 5-FU) dispersed in lipid contrast medium (Lipiodol, Laboratorie Guerbert, France) was used in an infant with initially unresectable hepatoblastoma. Lipiodol complex selectively accumulated in the tumor tissue and may keep the chemotherapeutic agents in the tumor tissue for a longer period of time, and a significant reduction of the tumor with a four-day half-life of alpha-fetoprotein (AFP) was followed immediately after the institution of chemotherapy. Successful resection of decreased tumor by extended right hepatectomy under more favorable conditions was performed 2 months after diagnosis. Intraarterial chemotherapy with Lipiodol was particularly useful in potentiating the cytoreduction of anti-tumor drugs and was also useful in reducing the toxicities of anti-tumor drugs to the host.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Development of cartilage-like tissue from androgen-dependent Shionogi carcinoma 115 in androgen-depleted hosts.

Androgen-dependent Shionogi carcinoma 115 (SC115) is an undifferentiated medullary carcinoma showing a compact cell pattern. When SC115 was inoculated into castrated DS mice, slowly growing tumors containing cartilage-like tissue developed. The cartilage-like tissue showed close similarities in electron microscopical and histochemical features to normal cartilage tissue. The origin of the cartilage-like cells was investigated by using the electrophoretic pattern of 3-phosphoglycerate kinase (PGK, EC 2.7.2.3) as a marker. The original DS strain had B-type PGK, but we developed a congenic strain with A-type PGK. The SC115 tumor, which had B-type PGK, was grafted into castrated congenic mice with A-type PGK. The cartilage-like tissue that developed was divided into two parts; one part was used for PGK analysis and the other for histological examination. All histologically confirmed cartilage-like tissues had only B-type PGK, suggesting that SC115 cells may change into cartilage-like cells in androgen-depleted conditions.

Androgens↗
PubMed1987

Inhibitory effect of prolonged oral administration of cetraxate hydrochloride on experimentally-induced intestinal metaplasia in Wistar rats.

The effect of cetraxate hydrochloride (Neuer) on the induction of intestinal metaplasia by intragastric instillation of 5% NaOH solution was investigated in Wistar rats. Oral administration of cetraxate, beginning 2 days after NaOH treatment, resulted in a significant increase in antral mucosal blood flow and a significant reduction in the incidence and amount of intestinal metaplasia in experimental week 25, but no significant changes in basal acid secretion or antral mucosal pH. On histological examination, goblet cell metaplasia were frequently seen. These results show that the increased gastric blood flow produced by cetraxate hydrochloride may be associated with the suppression of induction of intestinal metaplasias.

Administration, Oral↗
PubMed1987

Improvement of autonomic neuropathy after mecobalamin treatment in uremic patients on hemodialysis.

The effect of mecobalamin on autonomic neuropathy was evaluated in 20 hemodialyzed uremic patients; their mean age was 53 years and the duration of hemodialysis was 6.5 years; 14 were women. The cardiac beat-to-beat variation (BBV) was used as the measure of autonomic neuropathy. Twelve patients with normal BBV test results were either given 1,500 micrograms of mecobalamin daily for three months (six patients) or were untreated (six patients). The BBV test results did not change significantly over the three months in either the treated or untreated group, nor were there any significant between-group differences. Eight patients with abnormal results on the BBV test were given 1,500 micrograms of mecobalamin daily for six months. The mean BBV values increased significantly from 3.3 beats/min before treatment to 5.8 beats/min at six months (P less than 0.005); five of these patients (including three of the four patients with diabetes) showed normal BBV values by three months. It is concluded that mecobalamin can be used in the treatment of autonomic and peripheral neuropathy in both diabetic and nondiabetic patients with chronic renal failure.

Adult↗