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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 703 records · Page 39Linked to original sources
PubMed1984

[Clinical study on tissue polypeptide antigen (TPA) as a tumor marker].

We evaluated whether assay of tissue polypeptide antigen (TPA) in sera is valuable for the determination of cancer stages compared to other tumor markers such as CEA, AFP, beta2-microglobulin, ferritin, and elastase-1. The study population consisted of cancer patients (33 gastric cancers, 7 colo-rectal cancers and 15 hepatomas), 169 patients with benign gastro-enteric diseases and 72 healthy volunteers. The percentage of positive cases for TPA (higher than 200 u/l) was 61% in gastric cancer, 71% in colo-rectal cancer and 87% in hepatoma. In certain non-cancerous conditions, such as gastric ulcer (active stage), acute hepatitis and chronic hepatitis, the TPA levels were increased over the level of healthy volunteers. There was no significant correlation between TPA and the other tumor markers. Our study suggests that TPA may be useful in the identification and evaluation of cancer patients.

Adolescent↗
PubMed1984

Adrenoceptor blocking effects of arotinolol, a new combined alpha- and beta-adrenoceptor blocking agent.

In isolated tissues and anesthetized animals, beta- and alpha-adrenoceptor blocking properties of arotinolol were studied in comparison with those of other typical adrenoceptor antagonists. The following order of beta-adrenoceptor blocking activities were obtained in isolated tissues: arotinolol = pindolol greater than propranolol = oxprenolol = alprenolol greater than or equal to labetalol for beta 1-adrenoceptors (guinea-pig right atrium) and pindolol = oxprenolol = arotinolol greater than propranolol greater than labetalol for beta 2-adrenoceptors (guinea-pig trachea). In anesthetized cats, arotinolol was about 9 and 25 times more potent than propranolol, about 30 and 100 times more potent than labetalol in blocking beta 1- and beta 2-adrenoceptors, respectively. Furthermore arotinolol showed a competitive antagonistic effect on phenylephrine-induced contraction of isolated rat aortic strips. The relative order of alpha 1-adrenoceptor blocking potencies was as follows: prazosin greater than phentolamine greater than labetalol greater than arotinolol = yohimbine. Presynaptic alpha 2-adrenoceptor blocking action of arotinolol was also assessed in isolated rat vas deferens and arotinolol was revealed to be a much weaker presynaptic alpha 2-adrenoceptor antagonist. In anesthetized rats arotinolol was 4-5 times less potent than labetalol and about 26 times less potent than phentolamine in blocking alpha 1-adrenoceptors. Thus, as for the selectivity for 2 subtypes of alpha-adrenoceptors, arotinolol showed a selectivity for alpha 1-adrenoceptors over presynaptic alpha 2-adrenoceptors.

Adrenergic alpha-Antagonists↗
PubMed1984

[5'-Deoxy-5-fluorouridine enzymatic activation from the masked compound to 5-fluorouracil in human malignant tissues].

It has been reported that 5'-DFUR is converted to 5-FU by uridine phosphorylase in experimental animal tumors. The conversion of thymidine, uridine and 5'-DFUR as substrates was studied in tumor and normal tissues of human and animals. A further series of studies was performed using 1-(2'-deoxy-beta-D-glucopyranosyl) thymine (GPT), a specific inhibitor of uridine phosphorylase. We found that this conversion in human tumors was catalyzed not by uridine phosphorylase but by thymidine phosphorylase. It was also confirmed that the enzyme activities in various human cancers were significantly several times higher than those in adjacent normal tissues. We succeeded in tried and isolating thymidine phosphorylase in a fairly pure form, from which enzyme Km values were calculated. After administration of 5'-DFUR intravenously or orally to patents, tissue and blood samples were collected by biopsy or surgical operation to determine the 5-FU level. The 5-FU levels were always higher in tumor tissues than in the blood or in normal tissues. Finally effective clinical efficacy was demonstrated by oral administration of 5'-DFUR.

Administration, Oral↗
PubMed1984

[Measurement of 5'-deoxy-5-fluorouridine (5'-DFUR) by high-performance liquid chromatography and studies on pharmacokinetics of 5'-DFUR and 5-fluorouracil by oral and intravenous administration].

The authors have made clear that 5'-deoxy-5-fluorouridine (5'-DFUR), a derivative of 5-fluorouracil (5-FU), is activated by thymidine phosphorylase with has a particularly high activity in human malignant tumors. This derivative therefore, has fewer side-effects and can be expected to produce a greater antitumor effect when administered to cancer patients. Blood levels of 5'-DFUR and 5-FU were then observed with time after oral or intravenous 5'-DFUR administration in order to study its clinical effect. First, a method for measurement of 5'-DFUR and 5-FU was devised using high-performance liquid chromatography (HPLC). The results obtained using this method revealed that for intravenous administration both 5'-DFUR and 5-FU showed rapid drops in blood level while for oral administration both showed blood level peaks after one hour which were maintained of the same level for two hours, decreasing gradually thereafter. 5-FU showed a blood level peak after one hour, decreasing gradually thereafter. From the above results it was proved that a relatively high percentage of orally administered 5'-DFUR was absorbed from the intestine.

Administration, Oral↗
PubMed1983

Autoradiographic localizations of [35S]-sulfate and [3H]-glucosamine in the hamster ciliary epithelium.

The localization of [35S]-sulfate and [3H]-glucosamine in the hamster non-pigmented ciliary epithelium was studied by light and electron microscopic autoradiography. The radioactivity was concentrated in the Golgi complex of the non-pigmented ciliary epithelium 10 mins after injections of [35S]-sulfate or [3H]-glucosamine. Silver grains of both isotopes covered the cytoplasm 60 mins after the administration and were then associated with the basal infoldings. Radioactivity of [3H]-glucosamine was observed in the basal lamina of the non-pigmented ciliary epithelium and the ciliary zonule; however, the localization of [35S]-sulfate in the basal lamina and the ciliary zonule was not demonstrated. These data lend support to the idea that the non-pigmented ciliary epithelium may synthesize glycosaminoglycans (GAG) and secrete non-sulfated glycosaminoglycans into the posterior chamber.

Animals↗
PubMed1983

Ontogeny of neurotensin-containing neuron system of the rat: immunohistochemical analysis--II. Lower brain stem.

The ontogeny of the neurotensin neuron system in the lower brain stem of the rat was investigated by means of indirect immunofluorescent method. Neurotensin-like immunoreactivity-containing cells first appear in the primordium of the n. tractus solitarii, n. tractus spinalis nervi trigemini, reticular formation just medial to the latter nucleus, n. reticularis parvocellularis, n. laterodorsalis tegmenti, and midbrain reticular formation of the fetus at gestational day 17. At gestional day 18, neurotensin-immunoreactive cells newly appear in the n. raphe dorsalis. Between gestational day 19 and postnatal day 7, the animals show a remarkable increase in number of immunoreactive cells and fibers in various lower brain stem areas except for n. tractus spinalis nervi trigemini and n. tractus solitarii. Moreover, during this stage, neurotensin-immunoreactive cells located in the n. prepositus hypoglossi and n. vestibularis lateralis appear for the first time at birth and postnatal day 5, respectively. Since postnatal day 7, although the majority of immunoreactive cells located in the lower brain stem decrease in number as the rats grow, immunoreactive cells in the n. tractus spinalis nervi trigemini, on the contrary, increase in number from after birth until postnatal day 10, and maintain more or less their immunoreactivity even in the adult rat. In addition, neurotensin-immunoreactive cells in the nucleus of the solitary tract increase in number during the fetal period, reach the maximum content at postnatal day 7-10, and maintain their immunoreactivity even in the adult rats. Thus, the present study demonstrated that neurotensin-like immunoreactive structures appear at a very early ontogenetical stage, suggesting that neurotensin plays an important role in the development of the lower brain stem of the rat. In addition, the present study further showed that neurotensin-immuno-reactivity shows various fluctuations during the ontogeny, suggesting multiple functions of neurotensin in the central nervous system.

Animals↗
PubMed1983

Effects of the new beta-adrenoceptor blocking agent, S-596 on the peripheral autonomic nervous system and smooth muscles.

The effects of the new beta-adrenoceptor blocking agent, S-596, on the peripheral autonomic nervous system and smooth muscles were studied in comparison with propranolol. In urethane or alpha-chloralose anesthetized cats S-596 (10 micrograms/kg, i.v.) antagonized the cardiovascular responses induced by isoproterenol. S-596, in doses ranging from 100 to 300 micrograms/kg (i.v.) reduced the contractions of the nictitating membrane induced by electrical stimulation of preganglionic and postganglionic fibers to the superior cervical ganglion. Higher doses of S-596 were required to depress the effects of noradrenaline and tyramine. In spinal cats the tyramine and noradrenaline dose-response curve was shifted to the right by S-596. In isolated rat aortic strips S-596 displaced the noradrenaline dose-response curve to the right in a parallel fashion indicating a competitive antagonism. Its potency was about one tenth of that of phentolamine. These results suggest that S-596 possesses both alpha-and beta-adrenoceptor blocking activities.

Adrenergic beta-Antagonists↗