Search PubMed⌕ Search

Biomedical subjects

S Noda

Publications and source records attributed to S Noda.

At least 253 records · Page 14Linked to original sources
PubMed1987

Hepatic conversion of 1-(tetrahydro-2-furanyl)-5-fluorouracil into 5-fluorouracil in patients with hepatocellular carcinoma.

The pharmacokinetics of 1-(tetrahydro-2-furanyl)-5-fluorouracil (FT) and its conversion into 5-fluorouracil (FUra) in liver tissue were studied in ten patients with hepatocellular carcinoma (HCC). The plasma concentration of FT after its intravenous injection (dosage: 800 mg) was computerfitted to a bi-exponential function (C = Ae-alpha t + Be-beta t), indicating a two-compartment disposition. The pharmacokinetic parameters did not significantly differ between the five patients with, and the five without cirrhosis of the liver. The plasma concentrations of FUra likewise showed no significant difference between the two groups. The rates of FT degradation in the liver tissue homogenate were similar for four of the patients with cirrhosis (0.10 +/- 0.05 mumol/g liver protein/30 min) and four of those without it (0.13 +/- 0.05). The rates of cytochrome P-450-dependent FUra formation in the microsomal fraction of liver tissue from two patients (1.1 and 1.3 nmol/mg microsomal protein/30 min) were dramatically reduced to less than half of those of two control subjects (2.4 and 2.7). The estimated rates of FUra formation in the soluble fraction (105,000 X g supernatant fraction) from the two patients (0.1 and 0.13 nmol/mg protein/30 min) were almost identical to those from the controls (0.12 and 0.14), suggesting that the rate in the soluble fraction from HCC patients may not be as strongly affected as the rate in the microsomal fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Effects of a new second generation calcium channel blocker, nilvadipine (FR34235), on exercise-induced hemodynamic changes in stable angina pectoris.

The mechanism of the antianginal actions of nilvadipine was investigated in 11 patients with effort angina pectoris. Hemodynamic data were obtained by angina-limited supine multistage bicycle ergometer exercise testing before and after a single 6 mg dose of nilvadipine. Compared with chest pain during control exercise testing, pain at peak exercise disappeared or abated and the ST segment at peak exercise also showed less significant depression after administration of nilvadipine. At rest and at peak exercise, mean blood pressure, pulmonary artery wedge pressure and systemic vascular resistance decreased significantly, whereas heart rate and cardiac index increased significantly after nilvadipine. Rate-pressure product and stroke volume index did not change significantly. Coronary sinus flow at peak exercise increased significantly and total coronary vascular resistance at rest and at peak exercise decreased significantly after nilvadipine. The plasma concentrations of nilvadipine 1.5 hours after administration ranged from 1.15 to 8.23 ng/ml. These data suggest that the principal factors in the antianginal actions of nilvadipine are an increase in myocardial oxygen supply due to increased coronary blood flow and a reduction in myocardial oxygen demand mainly by a decrease in afterload and additionally by a decrease in preload.

Adult↗
PubMed1987

Observations on the transmission of Angiostrongylus cantonensis from snail to rodent.

A survey of Angiostrongylus cantonensis was carried out to investigate the mode of transmission from mollusc to rat in a fixed study area of Yoron Island from 1979 to 1982. Rattus rattus was found to be infected with a small number of worms in spite of heavy infection with third-stage larvae in Achatina fulica and an abundance of this snail in the area. Natural infection and/or susceptibility with A. cantonensis were confirmed in three small snail species. Bradybaena circulus, Fruticicola despecta and Luchuena reticulata. Young A. fulica was found to be infected with fewer third-stage larvae than mature A. fulica. It was concluded that molluscs which were infected with a small number of third-stage larvae of A. cantonensis play an important role in maintaining the life cycle of A. cantonensis. The percentage of rat stomachs containing mollusc tissue was relatively low, and the incidence and infection was low in rats. Infection with A. cantonensis did not occur very often in R. rattus in nature.

Angiostrongylus↗
PubMed1987

Effects of a new vasodilator, nicorandil, on exercise-induced impairment of left ventricular function in patients with old myocardial infarction.

Hemodynamic effects of nicorandil on exercise-induced impairment of left ventricular function were studied in nine patients with old myocardial infarction but without angina pectoris. Hemodynamic data were obtained by symptom-limited supine multistage bicycle ergometer exercise testing before and 1 h after single oral administration of 15 mg of nicorandil. Systolic and diastolic blood pressure at rest decreased significantly after nicorandil administration (p less than 0.01). A most remarkable change in the hemodynamic response to supine dynamic exercise after nicorandil was a decrease in pulmonary artery wedge pressure (both at rest and at peak exercise, p less than 0.001). An index cardiac function, obtained from the relation between pulmonary artery wedge pressure and left ventricular stroke work index, improved significantly after nicorandil. The ration of pressure-rate product to coronary sinus flow, which is an index of the ratio of myocardial oxygen consumption to myocardial oxygen supply, decreased significantly (p less than 0.05) after nicorandil administration. Reproducibility of the testings was also studied in six patients with old myocardial infarction. Invasive hemodynamic variables between two successive symptom-limited supine leg exercise testings, except pulmonary artery wedge pressure, were reproducible in patients with old myocardial infarction but without angina pectoris. Only pulmonary artery wedge pressure at rest in the second exercise testing showed a significantly lower value (p less than 0.05). It is concluded that nicorandil is a useful drug for improvement of exercise-induced impairment of left ventricular function with an increase in myocardial oxygen supply.

Adult↗
PubMed1987

[A case of hepatocellular carcinoma with bone metastasis which responded to oral administration of UFT].

A 61-year-old male was referred to our hospital for evaluation of right upper arm pain. He was diagnosed as having primary hepatocellular carcinoma with bone metastasis by his high titer (111,683 ng/ml) of serum alpha-fetoprotein, computed tomography and abdominal angiography, and so UFT therapy, 400 mg daily, was instituted. After 2 months of this therapy, the titer of serum alpha-fetoprotein gradually decreased. Seven months later, the titer was 3,997 ng/ml and reduction of the hepatic tumor size was shown by computed tomography and ultrasonography. Furthermore, the right upper arm pain diminished and X-ray examination revealed remarkable improvement. During chemotherapy, there was no severe side effect apart from mild anemia and the patient is presently still alive. This case suggests the efficacy of UFT for the treatment of primary hepatocellular carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Demonstration of a heterogeneous distribution of glycolytic enzymes and of pyruvate kinase isoenzymes types M1 and M2 in unfertilized hen eggs.

The intracellular distribution of the glycolytic enzymes hexokinase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase and the pyruvate kinase isoenzymes type M1 and type M2 within unfertilized hen eggs was studied. Most of glycolytic enzyme activities were found in the yolk fraction; 8-24% of total glycolytic enzyme activities were found in the vitelline membrane fraction. However, the specific activities of these enzymes in the vitelline membrane fraction are 19-72-fold higher (U/mg protein) and 45-178-fold more concentrated (U/g wet weight) than in the yolk fraction. The study of intracellular localization of pyruvate kinase isoenzymes shows that the blastodisc, latebra and vitelline membrane contain only pyruvate kinase type M2, whereas pyruvate kinase types M1 and M2 are found in the egg yolk. The exclusive occurrence of pyruvate kinase type M2 in the blastodisc is consistent with the concept that this isoenzyme is involved in the cell proliferation. The heterogeneous distribution of the glycolytic enzymes hexokinase, glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase, and the heterogeneous localization of the pyruvate kinase isoenzymes types M1 and M2 indicate that glycolysis is distributed heterogeneously within the unfertilized hen egg cell.

Animals↗
PubMed1986

Effects of isosorbide-5-mononitrate on exercise-induced hemodynamic changes in angina pectoris.

Hemodynamic effects of isosorbide-5-mononitrate (ISMN) were studied in 14 patients with effort angina pectoris. Hemodynamic and echocardiographic data were obtained by angina-limited supine multistage bicycle ergometer exercise testing before and 120 minutes after single oral administration of 20 mg of ISMN. Compared with control exercise testing, the ST segment at peak exercise showed less depression after administration of ISMN (p less than 0.001). At rest, systolic and diastolic blood pressure decreased significantly after administration of ISMN (p less than 0.001 and p less than 0.01, respectively). At rest and at peak exercise, pulmonary artery wedge pressure (both p less than 0.001), left atrial volume (both p less than 0.001) and left ventricular end-diastolic volume (both p less than 0.05) decreased, whereas cardiac index, pressure-rate product and systemic vascular resistance did not change significantly after administration of ISMN. Average time to peak plasma ISMN concentration was 90 minutes and average peak plasma concentration was 460 ng/ml with an elimination half-life of 7 hours. These data suggest that the main mechanism of the antianginal action of ISMN is a reduction in left ventricular preload followed by diminution of myocardial oxygen requirements.

Adult↗
PubMed1986

Purified pyruvate kinases type M2 from unfertilized hen's egg are substrates of protein kinase C.

To characterize pyruvate kinase isoenzymes from cells with the capability to proliferate, this enzyme was purified from yolk and vitelline membrane of unfertilized hen's egg. Pyruvate kinase type M2 from vitelline membrane was obtained in a homogeneous form after a 1150-fold purification to a specific enzymatic activity of 450 mumol X min-1 X mg-1. It was saturated half-maximally with phosphoenolpyruvate at KPPrv0.5 = 0.36 mM phosphoenolpyruvate and was activity by fructose 1,6-bisphosphate and L-serine at suboptimal substrate concentrations. After 11 000-fold purification to a specific enzymatic activity of 60 mumol X min-1 X mg-1, the pyruvate kinase isoenzymes type M2 (KPPrv0.5 = 0.32 mM) and M1 (KPPrv0.5 = 0.04 mM) were obtained from the yolk substance. Kinetic differences were noted between the pyruvate kinase type-M2 isoenzymes from vitelline membrane and yolk. A comparison of the amino acid composition of the purified pyruvate kinase isoenzymes from hen's egg revealed that all isoenzymes were related to pyruvate kinase type M1 from chicken breast muscle. The M2-type isoenzyme from vitelline membrane was related to the M2-type isoenzyme from chicken tumors, but was not related to the M2-type pyruvate kinase from chicken lung or liver. Protein kinase C from chicken oviduct phosphorylated in vitro both pyruvate kinase M2 isoenzymes from the unfertilized hen's egg preferably at serine and less at threonine residues. Pyruvate kinase type M1 from egg yolk was a weak substrate of protein kinase C. An activation of pyruvate kinase type M2 from vitelline membrane was observed at suboptimal concentrations of phosphoenolpyruvate under the conditions of phosphorylation, in the presence of phosphatidylserine.

Amino Acids↗
PubMed1986

Interaction of famotidine with rat liver microsomes, a study showing less inhibition of drug metabolism than with cimetidine.

Interaction of famotidine with rat liver microsomes and its effect on drug metabolism in vitro were studied. Famotidine interacted with liver microsomes obtained from untreated, phenobarbital-pretreated and 3-methylcholanthrene-pretreated rats to produce characteristic type II spectral changes with peaks at 423-426 nm and troughs at 387-390 nm. The spectral dissociation constants were in the range of 0.84-0.94 mM. Famotidine inhibited aminopyrine N-demethylase activity to a much lesser extent than did cimetidine. The extent of inhibition at a concentration of 5 mM of famotidine was from 12 to 18% for the microsomes from the rats with different pretreatments. In contrast, 5 mM of cimetidine inhibited the activity 80, 59 and 80% in the microsomes from untreated, phenobarbital-pretreated and 3-methylcholanthrene-pretreated rats, respectively. Both famotidine and cimetidine inhibited aminopyrine N-demethylase in a mixed-type manner for the microsomes from phenobarbital-pretreated rats, with inhibition constants of 4.7 and 0.7 mM, respectively. These results demonstrate that famotidine is an in vitro inhibitor of microsomal drug metabolism in rats but is much less inhibitory than cimetidine.

Aminopyrine N-Demethylase↗
PubMed1986

Familial spinocerebellar degeneration as an expression of adrenoleukodystrophy.

A family with adrenoleukodystrophy and clinical manifestations of spinocerebellar degeneration was studied. Two adult male first cousins showed progressive limb and truncal ataxia, slurred speech and spasticity of the extremities. Brain CT scans demonstrated atrophy of the pons and cerebellum, in both cases. Very long chain fatty acids in plasma and erythrocyte membranes were elevated in the affected patients and intermediately increased in an aunt and the mother of one patient, thereby indicating homozygotes and carriers of adrenoleukodystrophy, respectively. This unusual type of adrenoleukodystrophy seems to be transmitted as an X-linked recessive trait.

Adrenoleukodystrophy↗
PubMed1986

Development of the enteric nervous system in chick embryonic duodenum in terms of the distribution of tubulin.

An immunohistochemical method that uses anti-tubulin was utilized to observe the development of the enteric nervous system in chick embryonic duodenum. Neural crest cells, and enteric neuroblasts, or enteric ganglia, which derive from neural crest cells were clearly shown as sharp immunoreactive regions of tubulin. The distributions of enteric neuroblasts and enteric ganglia in chick duodena were in agreement with results of previous reports in which different techniques were used. The initial stage at which cells of neural crest origin were present in the duodenal walls (4-day-old embryos) was earlier than the initial stage (about 6-day-old embryos) reported earlier. This was verified by transmission electron microscopy. Also, the tubulin that is a component of the enteric nervous system was shown to be stable at a low temperature. This tubulin-immunostaining method provides a useful histochemical technique with which to study the development of the enteric ganglion and the function of tubulin as a component of the enteric nervous system.

Animals↗
PubMed1986

Analysis of the exercise-induced orthogonal P wave changes in normal subjects and patients with coronary artery disease.

Near-maximal treadmill exercise testing was performed on 26 normal individuals (NL) and 78 patients with coronary artery disease (CAD) using a modified Bruce's protocol. Exercise-induced changes in orthogonal P wave measurements were made automatically, using an averaging technique, immediately before and 30 sec after treadmill exercise to assess their diagnostic significance in evaluation of left ventricular (LV) function in CAD patients. The maximal inferior and posterior components of the P wave and the maximal P-vector magnitude in the frontal and left sagittal planes showed a statistically significant increase after treadmill exercise both in NL and CAD patients. These changes were considered to be physiological responses of the P wave to dynamic exercise. The percent changes of the maximal horizontal P-vector magnitude (%Hmax) were significantly higher after treadmill exercise in CAD patients than in NL. In patients with effort angina pectoris and without a previous myocardial infarction, the %Hmax showed a highly significant negative correlation with the percent changes of the LV ejection fraction (r = 0.66, p less than 0.01), measured by exercise RI angiography. These results suggest that the exercise-induced increase in %Hmax reflects transient impairment of LV function during exercise. It was concluded that a %Hmax of more than 120% provided a useful, noninvasive index for assessing LV function in treadmill exercise testing.

Adult↗