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Biomedical subjects

K Miyano

Publications and source records attributed to K Miyano.

At least 73 records · Page 4Linked to original sources
PubMed1988

[Bladder irrigation with prostaglandin E2 in cyclophosphamide-induced hemorrhagic cystitis].

A four-year-old boy with stage IV neuroblastoma was treated using the group study protocol of the Tohoku area for advanced neuroblastoma, consisting of DTIC, CPA, VCR, CDDP and VM-26, as a result of which had obtained complete remission. However, he had severe hemorrhagic cystitis after administration of CPA. He was treated with the usual therapy, but symptoms such as hematuria, pollakiuria and miction pain were not improved. We then tried bladder irrigation with prostaglandin E2. Half a milligram of PGE2 in 100 ml of physiological saline solution was instilled into the bladder and left in situ for 3 hours. The patient was free of symptoms on the day following the therapy. Local therapy with PGE2 thus seems very useful for cyclophosphamide-induced cystitis.

Administration, Intravesical↗
PubMed1985

Long-term survival of functional hepatocytes from adult rat in the presence of phenobarbital in primary culture.

In the presence of phenobarbital (PB) at 3 mM, hepatocytes isolated from adult rats by a collagenase-perfusion technique survived well on plastic dishes for at least 49 days after initiation of primary culture. PB at concentrations less than 3 mM was ineffective for the maintenance of hepatocytes, and the maintenance of them was attained only in the continuous presence of 3 mM PB. The hepatocytes surviving in the presence of 3 mM PB were morphologically indistinguishable from the hepatocytes after 1-day attachment period, except for the presence of prominent nucleoli in the former. Although both the albumin secretion and tyrosine aminotransferase (TAT) activities of the cells decreased gradually up to day 7 with time in culture, both were thereafter maintained at relatively high levels at least up to day 35 of primary culture. The addition of 10 microM dexamethasone caused a 3-5-fold induction in TAT activity, and the cells were capable of responding to the hormone in this manner at least up to day 28 of primary culture. Furthermore, the cells also had glucose-6-phosphatase activity, even though the level of this enzyme activity was relatively low as compared with that of TAT activity. Survival of hepatocytes in the presence of 3 mM PB was further enhanced by simultaneous addition of dexamethasone (10 microM) and insulin (10 micrograms/ml). The sensitivity of hepatocytes to 3'-methyl-4-dimethylaminoazobenzene (0.24 mM) was remarkably reduced by treatment with PB at 3 mM. PB treatment decreased efficiently the falling rate of total cytochrome P-450 content, but did not induce P-450PB, which is the specific form of cytochrome P-450 induced by PB, in primary cultured hepatocytes. On the other hand, 3-methylcholanthrene (MC, 10 microM) caused an increase of both contents of total cytochrome P-450 and P-450MC, which is the specific form of cytochrome P-450 induced by MC, in primary cultured hepatocytes. However, MC was ineffective for the maintenance of hepatocytes in primary culture. The possible biological actions of PB on primary cultured hepatocytes are discussed on the basis of the experimental data obtained.

Albumins↗
PubMed1985

Biotransformation of N-methylcyclobarbital in vivo in rabbit and rat.

Metabolism of N-methylcyclobarbital in the rabbit and rat has been studied in vivo for the purpose of comparison with the C5-methylated analogue, hexobarbital. In the rabbit, the main route of the metabolism of N-methylcyclobarbital is glucuronide formation after hydroxylation at the 3'-position of the parent compound. Dehydrogenation of the 3'-hydroxy product, a major pathway in the metabolism of hexobarbital, was a minor route in the case of N-methylcyclobarbital. In addition, a new type of metabolite, thought to be dihydroxylated products from spectral studies, was isolated. In the rat, there were almost no differences in the metabolic fates of N-methylcyclobarbital and hexobarbital. Profiles of metabolism of four analogous barbiturates (N-methylcyclobarbital, hexobarbital, cyclobarbital and norhexobarbital), which have a cyclohexene ring on the 5-carbon, reveal the contribution of alkyl substituents in the barbiturate ring on the bioavailability and metabolism of these compounds.

Animals↗
PubMed1984

Comparison of cytologic and biochemical properties between liver cells isolated from adult rats by trypsin perfusion and those isolated by collagenase perfusion.

Primary cultures of liver cells isolated from adult rats by trypsin and collagenase perfusion techniques were carried out to compare cytologic and biochemical properties between the differently prepared cells. Trypsin-dispersed cells consisted of comparatively smaller cells, whereas collagenase-dispersed cells consisted of larger cells. The cell attachment efficiency on culture day 1 was about twice as high in the liver cells prepared with collagenase than those prepared with trypsin. Mature hepatocytes isolated by collagenase perfusion could be maintained in the primary culture for a longer period than those isolated by trypsin perfusion. Epithelial-like clear cells started to grow much earlier in the primary culture of the trypsin-dispersed liver cells than in that of the collagenase-dispersed liver cells. Earlier proliferation of epithelial-like clear cells could not be induced by in vitro trypsinization of the collagenase-dispersed liver cells. Both kinds of enzymatically prepared liver cells showed albumin production and exhibited glucose 6-phosphatase (D-glucose-6-phosphate phosphohydrolase, EC 3.1.3.9, G6Pase) and tyrosine aminotransferase (L-tyrosine: 2-oxoglutarate amino-transferase, EC 2.6.1.5, TAT) activities for 1 week in the primary culture. Albumin production was higher in the liver cells prepared with collagenase than those prepared with trypsin, whereas G6Pase activity was almost the same between them. TAT activity up to culture day 2 was about 3-fold higher in the liver cells prepared with collagenase than in those prepared with trypsin. Combined supplementation of dexamethasone (1 X 10(-5)M) and insulin (10 micrograms/ml) consistently improved the cell attachment efficiency and was very effective in the maintenance of mature hepatocytes in both types. Furthermore, these hormones enhanced the albumin production and TAT activity in both types.

Albumins↗
PubMed1984

Pharmacological prevention of ocular inflammation induced by lens proteins.

Ocular inflammation was induced by lens protein to mimic the traumatic injury of the eyes. Pretreatment of the eyes with indomethacin resulted in marked reduction of this ocular inflammation in the early phase. Pretreatment of the eyes with phenidone and nordihydroguaiaretic acid (NDGA) on the other hand reduced ocular inflammation during both early and late phases. These results indicate that prostaglandins are involved in early phase of the inflammation which can be reduced with cyclooxygenase inhibitors such as indomethacin and leukotrienes are responsible primarily in the later phase because they are suppressed by lipoxygenase inhibitors such as phenidone and NDGA. Although histamine is implicated in the process of inflammation, the H1-antagonist, pyrilamine, had very little effect on ocular inflammation, whereas the H2-antagonist, cimetidine, exhibited no effect but rather enhanced the ocular inflammatory responses at the peak of inflammation. These results are not in accord with published findings.

Aminopyridines↗