Search PubMed⌕ Search

Biomedical subjects

Y Ohno

Publications and source records attributed to Y Ohno.

At least 523 records · Page 29Linked to original sources
PubMed1988

Prediction of the gastric cancer mortality in 2000 in Japan.

Gastric cancer mortality in Japan in the year 2000 has been predicted from sex- and age-specific incidences and mortality trends and patient cure rates. The difference between the log-linear decrease in incidence and the log-quadratic decrease in mortality was considered to be the result of early diagnosis and treatment. Even on the assumption that 90% of patients could be cured in 2000, the number of deaths was estimated to be about 10,000. The decreasing incidence of cases brought about by birth cohort effects may contribute towards lowering the number of patients. The importance of health education in lowering the incidence of gastric cancer, by teaching people to keep up a sound life style, is discussed.

Age Factors↗
PubMed1988

The regulation of intracellular transport of cholesterol in bovine adrenal cells: purification of a novel protein.

We have purified to homogeneity a protein from bovine adrenal (fasciculata) cells that is capable of: 1) stimulating synthesis of pregnenolone (in a concentration-dependent fashion) by mitochondria when added with exogenous cholesterol; 2) increasing the concentration of cholesterol in outer and inner membrane when added to mitochondria with exogenous cholesterol; 3) increasing the rate of transport of cholesterol from outer membrane to inner membrane when the two membranes are incubated together in an aqueous buffer and subsequently separated by centrifugation; and 4) increasing the proportion of molecules of C27 side-chain cleavage P-450 that are bound to the substrate cholesterol. The protein is homogeneous according to two-dimensional polyacrylamide gels, shows a molecular weight of 8200 and is therefore referred to as 8.2 K. It is proposed that 8.2 K may be involved in the regulation of steroid synthesis in bovine fasciculata cells, possibly by stimulating entry of cholesterol into the outer membrane and by altering the intramitochondrial distribution of this substrate.

Adrenal Cortex↗
PubMed1988

Inhibitory effects of L-threo-DOPS, an L-noradrenaline precursor, on locus coeruleus-originating neurons in the caudate nucleus.

Electrophysiological studies using reserpine-treated cats were carried out to elucidate the effects of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on the noradrenergic pathway from the locus coeruleus (LC) to the caudate nucleus (CN) neurons, which were activated by iontophoretically applied bromocriptine, a dopamine D-2 receptor agonist. In the CN neurons, glutamate-induced firing was inhibited by iontophoretic application of noradrenaline, but not by repetitive stimulation of the LC or iontophoretically applied L-threo-DOPS. After intraventricular administration of L-threo-DOPS, however, LC stimulation inhibited the glutamate-induced firing. These results suggest that L-noradrenaline that was produced from the conversion of L-threo-DOPS inhibited the CN neurons which possess dopamine D-2 receptors.

Animals↗
PubMed1988

Effects of various inducers on the activities of cytochrome P-450-mixed function oxidases and aflatoxin B1 activation in microsomes of hamster livers.

The effects of various inducers on the activities of drug-metabolizing enzymes including aflatoxin B1 activation were studied in Syrian golden hamsters. Activity for aflatoxin B1 was determined by aflatoxin B1-DNA adducts formation. The treatments of hamsters with 3-methylcholanthrene, alpha-naphthoflavone and benzo(a)pyrene elevated markedly the activity for aflatoxin B1 by 2460, 1380 and 450%, respectively. Phenobarbital induced slightly and isosafrole and ethanol did not induce the activity for aflatoxin B1. Pregnenolone-16 alpha-carbonitrile decreased aflatoxin B1 activation to 51% of that of the non-treated animals. These results were in good accordance with the induction rate of a form of cytochrome P-450 (P-450AFB) which has potent activity to aflatoxin B1. Characteristics in the induction of mixed function oxidases of hamsters by these inducers, especially in respect to benzo(a) pyrene metabolizing enzyme, seemed to differ from those of rats. These results suggest that the activity for aflatoxin B1 in hamster is inducible by 3-methylcholanthrene-type inducers and that hamster is a suitable animals model to study the mechanism of aflatoxin B1-hepatocarcinogenesis.

Aflatoxin B1↗
PubMed1988

[Experimental study of orthotopic liver transplantation in dog--with reference to change of hepatic function, serum insulin, glucagon, c-AMP after liver transplantation and the viability of the graft].

The viability of the graft after liver transplantation is considered to be expressed as the sum of the hepatocellular activity by re-flowing of the hepatic blood flow after transplantation and the hepatocellular injury derived from the cold ischemia of the liver which is indispensable for transplantation. In order to elucidate the hepatocellular injury in ischemic liver graft cold ischemic liver model without hepatectomy was prepared and liver functions, serum insulin, glucagon and cyclic AMP after glucagon loading were measured. The following results were obtained. 1) Influence of anoxia due to ischemia of the liver expressed by s-GOT, disappeared 2 days after operation but it lasted for long time by s-GPT. Re-elevation of s-GOT, s-GPT observed after 2 days or more was considered to be derived from the hepatocellular necrosis due to rejection. Incidentally, Al-phosphatase was useful for judging the rejection, but s-total bilirubin, s-total cholesterol and albumin were considered to be not useful as parameters for evaluating the viability of the graft. 2) The rejection and the hepatocellular necrosis had not influence on serum insulin, but serum glucagon corresponded to the hepatocellular necrosis and was useful index for the judgment of the hepatocellular damage in the graft. 3) The level of c-AMP after glucagon loading and the c-AMP response corresponded very well to the hepatocellular activity of the graft, and they were considered to be useful indices for evaluating the viability of the graft.

Animals↗
PubMed1988

On age-related norms of the visual field.

We prospectively studied the influence of age on visual fields obtained from 108 normal subjects (147 eyes) by using the Humphrey Field Analyzer (Program 30-2). Differential light sensitivity remained constant irrespective of age until the age of 35 to 44 years in the vast majority of test locations and then decreased linearly with age. The rate of linear decline differed at different test locations and failed to correlate with the eccentricity from the fixation, although its variance increased with the eccentricity. The mean sensitivity and the volume of the visual field were also constant until the age of 37.4 and 37.6 years, respectively.

Adolescent↗
PubMed1988

[Epidemiology of lymphoid malignancy].

Number of malignant lymphomas and leukemias in Japan from 1955 to 1983 was analyzed. Regional aggregation and trend in lymphoid malignancies from 1973 to 1983 clarified that southern Kyushu and Okinawa were high mortality areas. Autopsied cases (43,044 between 1974-84) showed the similar trend. Risk factors for lymphoid malignancies were reviewed.

Female↗
PubMed1988

[Surgical reconstruction for subclavian arterial obstruction at its origin].

The authors, having experienced 17 cases of subclavian arterial obstruction at its origin in Montpellier, France and in Japan, performed direct anastomosis between the divided end of the proximal subclavian artery and the ipsilateral common carotid artery (transposition technique) in 12 cases. Our series of 17 patients ranging in age from 30 to 73 years who were evaluated for variety of symptoms: 8 had subclavian steal syndrome; 12 had claudication of upper extremity; 1 had visual disturbance; 3 had vertigo; and 1 had ear throbbing. Twelve patients were treated surgically with division of the proximal subclavian artery and its anastomosis to the common carotid artery by means of supraclavicular cervicotomy. One was treated with carotid subclavian bypass grafting, and 4 were placed aorto-carotid-subclavian bypass grafting with median sternotomy because of the proximal occlusive lesions at the origins of common carotid and subclavian artery due to aortitis syndrome. All the patients were relieved from the symptoms which had been existed in pre-operative stage. The transposition technique is simple, effective and few complications.

Adult↗
PubMed1987

Detection of 1-beta-D-arabinofuranosylcytosine incorporation into DNA in vivo.

The incorporation of (1-beta-d-arabinofuranosylcytosine (ara-C) into the DNA of leukemic cells is highly correlated with cytotoxicity in vitro. However, the measurement of ara-C incorporation into leukemic cell DNA in vivo during ara-C therapy has been limited by the lack of a suitably sensitive method. A quantitative assay procedure has therefore been developed to determine incorporation of unlabeled ara-C into DNA. This method involves DNA isolation from patient myeloblasts, enzymatic digestion of the DNA, high pressure liquid chromatography separation of the nucleosides, and determination of ara-C in the eluate fractions by radioimmunoassay. Using this approach, incorporation of unlabeled ara-C into DNA of HL-60 cells is log linear over concentrations of 1 to 100 microM ara-C. Furthermore, the extent of ara-C incorporation into DNA as determined by this method correlates significantly with measurements of [3H]ara-C (DNA) formation under similar conditions. This approach has also been applied to clinical samples. Myeloblasts from 6 patients receiving high-dose continuous-infusion ara-C therapy incorporated 0.00-0.36 pmol ara-C/microgram DNA during 24 h of therapy. These findings thus suggest that this method can be used to monitor the in vivo incorporation of ara-C into leukemic cell DNA.

Adult↗
PubMed1987

Effects of L-threo-DOPS, an L-noradrenaline precursor, on locus coeruleus-originating neurons in spinal trigeminal nucleus.

Electrophysiological studies using reserpinized cats were performed to examine the effects of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on the noradrenergic pathway from the locus coeruleus (LC) to the spinal trigeminal nucleus (STN). The spike generation of STN relay neurons induced by trigeminal nerve stimulation was not affected by LC conditioning stimulation nor iontophoretic application of L-threo-DOPS. After intraventricular administration of L-threo-DOPS, the inhibition of the spike generation was seen with LC conditioning stimulation and blocked by iontophoretically applied sotalol, suggesting that L-noradrenaline converted from L-threo-DOPS inhibits transmission of STN relay neurons.

Action Potentials↗
PubMed1987

Excitatory and inhibitory effects of dopamine on neuronal activity of the caudate nucleus neurons in vitro.

Effects of dopamine on the rat caudate nucleus neurons were examined in a slice preparation using an intracellular recording technique. Perfusion of the bath with a low concentration (1 microM) of dopamine produced a depolarization concomitant with an increase in the spontaneous firing and the number of action potentials evoked by a depolarizing pulse applied into the cells. In contrast, higher concentrations (100-500 microM) of dopamine inhibited the spontaneous and current-induced firings without apparent effects on the resting membrane potential. In addition, during application of a high concentration (100 microM) of dopamine there was a marked elevation of the threshold potential of the action potential elicited by a higher depolarizing current. Simultaneous application of haloperidol (0.5-5 microM) antagonized both excitatory and inhibitory effects induced by the low and high concentrations of dopamine, respectively. In addition, the excitatory effect induced by a low concentration (1 microM) of dopamine was antagonized by domperidone (0.5 microM), a selective D2 receptor antagonist, while the inhibitory effect by a high concentration (100 microM) was blocked by SCH 23390, a selective D1 receptor antagonist. These results strongly suggest that the postsynaptic sites of caudate nucleus neurons have at least two subtypes of dopamine receptors (D1 and D2 receptors) that mediate inhibitory and excitatory responses of the neuron to dopamine, respectively.

Action Potentials↗
PubMed1987

Coexistence of inhibitory dopamine D-1 and excitatory D-2 receptors on the same caudate nucleus neurons.

Microiontophoretic studies using cats anesthetized with alpha-chloralose were performed to determine whether or not dopamine D-1 and D-2 receptors co-exist in the same caudate nucleus (CN) neurons that receive inputs from the substantia nigra (SN), and in which spikes elicited by SN stimulation were blocked by domperidone, a selective D-2 antagonist. Iontophoretic application of dopamine produced a dose-dependent inhibition of spontaneous firing in 2 of 4 spontaneously active CN neurons and an increase in firing in the remaining 2 neurons. However, dopamine inhibited the glutamate-induced firing in 31 of 32 CN neurons that were not spontaneously active. Similar inhibition with iontophoretically applied SKF 38393, a selective D-1 agonist, was observed in 33 of 34 spontaneously inactive neurons tested. When the effects of dopamine, SKF 38393 and bromocriptine (D-2 agonist) were examined on the same CN neurons, the inhibitory effects of both dopamine and SKF 38393 were seen in 14 of 15 neurons, and both an inhibition by SKF 38393 and an excitation by bromocriptine were observed in 15 of 17 neurons. The inhibitory effects of dopamine and SKF 38393 were antagonized by haloperidol and SCH 23390 (D-1 antagonist) without being affected by domperidone. Furthermore, the dopamine-induced inhibition was converted to an excitation during simultaneous application of SCH 23390 in 6 of 10 CN neurons, and this excitation was antagonized by domperidone. These results strongly suggest that the inhibitory D-1 and excitatory D-2 receptors co-exist on the same CN neurons receiving inputs from the SN.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗