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K Onodera

Publications and source records attributed to K Onodera.

At least 235 records · Page 13Linked to original sources
PubMed1992

[Three-dimensional radiologic device as a new diagnostic aid in angiocardiography].

Angiography with 180 degrees arc was performed using a rapidly rotating stereoradiographic device and a single injection of contrast medium. Duration of rotation of the X-ray tube through 180 degrees was 2.25 sec. The angiograms displayed in a rotating manner were three-dimensional with depth information. Every adjacent angiograms were obtained by the rapidly rotating X-ray tube at slightly different angles and positions, resulting in paired stereo images. The angiograms can be displayed on side-by-side monitors and viewed stereoscopically with a stereoviewer. Rotating images were displayed at 30 frames/sec (60 fields/sec) and were viewed in a fluorographic manner. To apply the data to angiocardiography the following procedures were required: 1) the start of rotation of the X-ray tube was synchronized with the R wave of the EKG, 2) suspension of respiration, and 3) the subject's upper extremities were immobilized at his head. To obtain left atrial angiograms the following steps were taken: 1) the circulation time from the pulmonary artery to the left atrium was estimated by injecting 15 ml contrast medium into the pulmonary artery under the fixed X-ray tube, then, 2) X-ray exposures of 20 fields/sec were obtained during 15 sec, and 3) left atrial arteriograms were taken by using the rotating X-ray tube referring to the circulation time. With this method, stenotic lesions of the coronary arteries and collateral pathways were easily observed simultaneously with morphological changes in a 180 degrees arc.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiocardiography↗
PubMed1992

[Continuous monitoring of coronary venous oxygen saturation during PTCA and its relation to electrocardiographic ST changes].

The purpose of this study was to investigate change in coronary venous oxygen saturation (CSO2-Sat) during percutaneous transluminal coronary angioplasty (PTCA) and to compare the results with those of standard 12-lead ECGs (s-ECG) and epicardial ECG induced using an intracoronary guidewire (ic-ECG). CSO2-Sat was measured continuously in 10 patients undergoing PTCA; 5 patients with lesions in the left anterior descending coronary artery (LAD), one with lesions in the left circumflex artery (LCX), and 4 with right coronary artery (RCA) lesions. The results were as follows: 1. In all 6 patients with stenotic lesions in the left coronary artery, CSO2-Sat decreased by 5 to 22% immediately after balloon inflation. Significant changes in ic-ECG (ST deviation > or = 0.1 mV) were observed in 5 of the 6 patients, while significant changes in s-ECG (ST deviation > or = 0.1 mV) were observed in only 3 of the 6 patients. The s-ECG did not seem to be sensitive enough to represent myocardial ischemia in the LCX. 2. The interval from the balloon inflation to the significant change was shorter for CSO2-Sat than for the ECGs in 4 of the 5 patients with LAD lesions, except Case 4. The recovery time of CSO2-Sat to the basal level on balloon deflation was longer than the recovery times of ic-ECG and s-ECG. 3. There was no significant change in the CSO2-Sat in 3 of the 4 patients undergoing PTCA for RCA lesions, while significant changes were observed in the ic-ECG and s-ECG in all 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1992

Reactions of copper(II)-N-polycarboxylate complexes with hydrogen peroxide in the presence of biological reductants: ESR evidence for the formation of hydroxyl radical.

The formation of hydroxyl radicals (.OH) by the reaction of CuII(edta) (edta: ethylenediaminetetraacetic acid) with hydrogen peroxide (H2O2) in the presence of biological reductants, such as L-ascorbic acid and L-cysteine, has been demonstrated for the first time by ESR spectroscopy using water-soluble spin-traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO, 1), alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN, 2) and 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS, 3). Ethylenediaminetetraacetic acid (edta) is one of the polyamine-N-polycarboxylate chelating agents and it is commonly used by chemists and biochemists. Edta can chelate several metal ions. It is known that the CuII(edta) complex is usually less active than free copper ions in radical reactions, whereas complexes of edta with Fe(II) or Fe(III) still react with hydrogen peroxide (H2O2) or superoxide ion (O2-) (1). In our previous papers (2-4), we also have shown that copper(II) complexes with polyamine-N-polycarboxylates, such as edta and dtpa (diethylenetriaminepentaacetic acid), do not react with H2O2, whereas CuII(en)2 (en: ethylenediamine) can easily do so to give hydroxyl radical (.OH) as a reactive intermediate. Further, we assumed that the change of redox potential of Cu(II) ions as a result of ligation with different ligands causes the difference in reactivity of Cu(II) complexes towards H2O2. To verify this assumption, the reactions of CuII(edta), which was chosen as a Cu(II)-polyamine-N-polycarboxylate complex, with H2O2 were investigated in the presence of some biological reductants, using an ESR-spin trapping method.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascorbic Acid↗
PubMed1992

[Inverse relationship between coronary flow velocity and myocardial oxygen extraction during intracoronary infusion of papaverine].

The relationship between coronary blood flow velocity (CBFV) and myocardial oxygen extraction (O2-Ext) was investigated during rapid changes of CBFV after intracoronary papaverine infusion. In 6 patients without stenosis of the left anterior descending artery (LAD), one with hypertrophic cardiomyopathy, 2 with syndrome X and 3 with effort angina pectoris, simultaneous measurements of CBFV using the Doppler catheter system and coronary venous oxygen saturation using the fiberoptic catheter system were continuously performed before and during intracoronary infusion of papaverine. When O2-Ext was related to CBFV in every cardiac cycle, there was a good, inverse linear relationship, both in the increase (r = 0.81 +/- 0.24) and decrease (r = 0.93 +/- 0.04) phases of CBFV. The increase in cross-sectional area of segment 6 in the LAD as observed on orthogonal coronary angiograms was 6.0 +/- 2.0%. These results imply that the increase in CBFV during intracoronary papaverine infusion seems parallel to that of coronary blood flow, and that papaverine induces no significant change in myocardial oxygen consumption. Myocardial oxygen extraction in response to changes in coronary flow is regulated readily to meet the myocardial oxygen demand.

Adult↗
PubMed1992

[Gene rearrangement analysis of conjunctival malignant lymphomas].

Specific DNA probes for genes encoding immunoglobulins (Ig) and the T cell receptor (TCR) are useful diagnostic tools in lymphoproliferative disorders. Gene rearrangement analysis was carried out in 2 cases of conjunctival lymphoid lesions. A 36-year-old man (case 1) had a 1-year history of left conjunctival tumor. A biopsy was performed and histopathological findings showed diffuse proliferation of small lymphocytes, but monoclonality was not revealed by immunophenotypic analysis. A right conjunctival lesion developed and five months later a biopsy of the left conjunctiva was performed again. A frozen sample was analyzed and immunoglobulin heavy chain gene rearrangement was found. A 53-year-old woman (case 2) had a 6-month history of bilateral conjunctival tumor. The first biopsy did not reveal monoclonality immunophenotypically. A second biopsy with a frozen specimen was analyzed and immunoglobulin heavy chain gene rearrangement was found. We diagnosed these two cases as B-cell lymphoma. We discuss the clinical value of gene rearrangement analysis as a diagnostic method for lymphoproliferative disorders.

Adult↗
PubMed1992

[Are the first repetitive reentrant VPCs a trigger or an initiation of reentrant circuit for VPCs?: Evaluation by Holter ECG in patients with reentrant sustained ventricular tachycardia].

To evaluate whether the first repetitive reentrant VPCs are a trigger or an initiation of a reentrant circuit for VPCs, we studied Holter ECGs in 13 patients with sustained ventricular tachycardia, the morphology of reentrant VPCs, the relationship between the coupling interval (N-V) and the first ventricular cycle length (V-V), and the relationship of the coupling interval (N-V) between single VPC and repetitive VPCs. In 7 patients who showed episodes of repetitive VPCs more than twice on one recording of Holter ECG, most of VPCs in the first and second beats were the same in shape (1195 out of 1466 episodes, 82%). No obvious relationship between the coupling interval (N-V) and the first ventricular cycle length (V-V) was found in 5 patients, whereas a weak inverse relationship (r = 0.32) was found in one patient, and a weak positive relationship (r = 0.38) was found in another patient. In addition, the coupling interval in repetitive VPCs was longer than that in single VPCs in 4 out of 7 patients. These results imply that, in most cases, the first VPC is the expression of initiation of a reentrant circuit for repetitive reentrant VPCs developing spontaneously.

Adult↗
PubMed1992

[A study of progression in hepatocarcinogenesis using cell transplantation system].

It is important to distinguish a precancerous lesion and hepatocellular carcinoma (HCC) with diploidy or aneuploidy nuclear DNA pattern, not only in clinical cases but also in experimental carcinogenesis models. Using liver perfusion technique, we detected early HCC from persistent hyperplastic nodules (HN) which were induced in Wistar rats by intermittent 5-6 months administration of 2-acetylaminofluorene. This investigation was undertaken to assess both promotive and progressive effects of liver regeneration following partial hepatectomy (PH). Results are as follows: 1) Isolated hepatocytes of precancerous HN, which were transplanted into the spleen, didn't develop to HCC by 2 months after 70% PH of host liver. 2) Diced tissues of HCC, which were transplanted into the liver via portal vein, grew many metastasis in 10/10 by 7 weeks after PH, while 5/19 in control. 3) Nuclear DNA patterns of early HN-late HCC in rat liver were diploidy at the rate of more than 90% each. But it changed to aneuploidy, when inoculation of HCC for one month was repeated 7 times in the spleen.

Animals↗
PubMed1992

[Evaluation of myocardial oxygen extraction dynamics in syndrome X by continuous measurement of coronary sinus oxygen saturation and its relation to clinical features].

We investigated the relation of myocardial oxygen extraction dynamics to pathophysiology and clinical features in syndrome X. In patients with syndrome X who underwent cardiac catheterization, coronary sinus oxygen saturation (n = 21) during rapid atrial pacing loading was continuously measured using a fiberoptic catheter system, and global and regional left ventricular function (n = 14) was evaluated before and immediately after pacing loading. Results were as follows: 1) In 5 of 21 patients with syndrome X, coronary sinus oxygen saturation during pacing loading fell less than 5% below the baseline without any impairments of global and regional left ventricular function. 2) In 16 patients with syndrome X, coronary sinus oxygen saturation during the pacing loading continuously fell over 5% below the baseline accompanied by impairment of both global and regional left ventricular function. The decrease in regional wall motion of the left ventricle was mainly observed in the apical area. These findings imply that changes in myocardial oxygen extraction dynamics in syndrome X during rapid atrial pacing may show the extent of a patchy area where myocardial oxygen demand-supply imbalance occurs due to coronary microcirculatory disturbances.

Adult↗
PubMed1992

Effects of alpha-fluoromethylhistidine on locomotor activity, brain histamine and catecholamine contents in rats.

One hour after the intraperitoneal (i.p.) injection of FMH (200 mg/kg), locomotor activity and rearing were statistically reduced, by 3 hours later, only the locomotor activity was reduced in rats. The i.p. injection of FMH (100 and 200 mg/kg) had no effects on motor incoordination, blood pressure, heart rate and tetrabenazine-induced ptosis in rats. One and 3 hours after FMH injection, the histamine levels significantly decreased in the hypothalamus, cortex and thalamus, slightly in the olfactory bulb, amygdala, pons-medulla oblongata and midbrain, but very little in the striatum, hippocampus, cerebellum and pituitary. On the other hand, noradrenaline and dopamine levels were not affected in most of the regional parts, although in the cortex and midbrain, the dopamine levels were slightly reduced 1 hour after FMH (100 and 200 mg/kg). These data showed that central histamine may play an important role in the locomotor activity of rats.

Animals↗
PubMed1992

[A case of atrial standstill associated with combined valvular disease].

A 62-year-old man was admitted to our hospital because of general malaise. The chest X-ray film showed severe cardiomegaly (CTR = 81%). The electrocardiogram demonstrated absence of P wave in 12-leads and regular junctional rhythm with incomplete right bundle branch block. Echocardiogram and color Doppler led to the diagnosis of mitral stenosis and regurgitation, tricuspid regurgitation with enlarged left and right atrium. Cardiac catheterization study revealed elevation of the pulmonary artery wedge pressure and the right atrial pressure without A wave. In the electrophysiologic study, no atrial electrical activity was recorded in the right atrium and the coronary sinus. However, when atrial pacing was attempted at multiple sites with stimulum strength of 10 V, there was no atrial activity at various sites. We considered that the atrial overload due to combined valvular disease for seventeen years had resulted in total and persistent atrial standstill. In this report, we discussed atrial standstill in 67 cases recorded in the medical literatures in our country.

Echocardiography↗
PubMed1991

Pharmacological characteristics of catalepsy induced by intracerebroventricular administration of histamine in mice: the importance of muscarinic step in central cholinergic neurons.

Histamine-induced catalepsy was antagonized potently by scopolamine, an antimuscarinic drug, and partially blocked by sparteine. Neither methylatropine nor antinicotinic drugs could reverse histamine-induced catalepsy. These results indicate the greater importance of muscarinic receptors rather than their nicotinic counterparts in histamine-induced catalepsy. Various antiparkinson drugs, i.e. biperiden and trihexyphenidyl, which have antimuscarinic activity or dopamine agonists, i.e. L-dopa, amantadine and bromocriptine, could antagonize the histamine-induced catalepsy to various degrees. Thus, catalepsy induced by icv histamine can be evoked not only by an activation of the histamine receptor, but also indirectly due to cholinergic and dopaminergic imbalance.

Amantadine↗
PubMed1991

Somatosensory evoked potentials following stimulation of median and tibial nerves in patients with localized intracerebral hemorrhage: correlations with clinical and CT findings.

Median and tibial somatosensory evoked potentials (SEPs) were performed on 38 patients with localized intracerebral hemorrhage, 23 with thalamic hemorrhage and 15 with putaminal hemorrhage. Of 65 arms and 62 legs examined, cerebral evoked responses of 60 arms and 50 legs were diagnosed as abnormal. The abnormal findings in scalp-recorded SEPs consisted of a reduction in amplitude, loss of waves and delay in peak latencies. The SEP abnormalities were not indicative of location of hemorrhage. Absence of SEPs was more frequently observed in large hemorrhages and at the early stage. Substantial improvement in SEPs was observed over several months after stroke in many limbs. Motor function as evaluated with Brunnstrom staging of the upper limbs whose SEPs were absent was lower than that whose SEPs were evoked, but that was not observed in the lower limbs because in some cases absence of SEPs coexisted with good motor function. Loss of SEP waves had a significant correlation with disturbed deep sensation. The median and tibial SEPs provided an excellent clinical correlation with the patients' improvement over several months.

Adult↗
PubMed1991

Effects of thioperamide, a histamine H3 receptor antagonist, on locomotor activity and brain histamine content in mast cell-deficient W/Wv mice.

The purpose of this study was to examine the effects of thioperamide, a histamine H3 antagonist, on the locomotor activity and the brain histamine content in mast-cell-deficient W/Wv mice. Thioperamide (12.5 and 25 mg/kg) showed significant increase in the locomotor activity of W/Wv mice, measured by a photo-beam system, 1 hr after the intraperitoneal injection. However, more than 75 mg/kg of thioperamide showed not only the reduction of the locomotor activity but also the inhibition of motor coordination measured by the rotarod performance. The increase in the locomotor activity by thioperamide was blocked by i. p. pretreatment with (R)-alpha-methyl-histamine, an H3 agonist, or pyrilamine, an H1 antagonist, or zolantidine, an H2 antagonist. The brain histamine content was decreased by thioperamide (12.5-75.0 mg/kg), 1 hr after administration. Thus, the blockade of histamine H3 receptor by thioperamide showed the activation of locomotor activity of mice, which may be mediated by H1 and/or H2 receptors. The present data support the hypothesis that central histaminergic neurons may be involved in the control of state of wakefulness.

Animals↗
PubMed1991

Crystallization and preliminary X-ray studies of a Bacillus subtilis and Thermus thermophilus HB8 chimeric 3-isopropylmalate dehydrogenase.

A chimeric gene was constructed by fusing the Bacillus subtilis and Thermus thermophilus genes coding for 3-isopropylmalate dehydrogenase, and expressed in Escherichia coli. The chimeric enzyme was crystallized in a size suitable for X-ray structure analysis. The crystal has a space group of P3(1)21 or P3(2)21, a = b = 77.1 A and c = 158.3 A, which is isomorphous with that of the native enzyme from T. thermophilus.

3-Isopropylmalate Dehydrogenase↗