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Biomedical subjects

A Ono

Publications and source records attributed to A Ono.

At least 199 records · Page 11Linked to original sources
PubMed1991

Possible role of sodium-hydrogen antiport in acetylcholine-induced relaxation of rat aorta.

The decreased extracellular Na concentration (25mM) attenuated vasodilator effect of acetylcholine (ACh) in norepinephrine-treated aortic ring. This attenuation was greater in the low Na medium substituted by Li, which can exchange intracellular H through Na-H antiport, as compared with that substituted by choline, which cannot. 10 microM amiloride canceled the difference between the two low Na mediums. Thus the inhibition of Na-H antiport may counteract the suppressive effect of decreased intracellular Na on ACh vasodilation, suggesting a possible role of Na-H antiport in a release of vasoactive substance(s) from endothelial cells.

Acetylcholine↗
PubMed1991

Conformational structure of a monoclonal anti-idiotypic antibody to the monoclonal anti-adenocarcinoma-associated carbohydrate antibody YH206.

The mAb AI206 (IgG1) is an anti-Id antibody of mAb YH206 (IgM) to adenocarcinoma-associated carbohydrate Ag and inhibits the reaction of mAb YH206 to YH206 Ag at low concentrations. By Western blot analysis, mAb AI206 only reacted with unreduced mAb YH206, whereas it did not react with reduced mAb YH206. Furthermore, mAb AI206 reacted with IgM subunit (180 kDa), F(ab')2 (110 kDa), and F(ab) (50 kDa) of pepsin-treated unreduced mAb YH206. Thus, mAb AI206 recognized the structure of F(ab) of mAb YH206. The mAb YH206 reacted with unreduced mAb AI206, F(ab')2 (110 kDa), and F(ab) (50 kDa) of pepsin-treated unreduced mAb AI206. It is presumed that mAb YH206 and mAb AI206 recognize each other in an unreduced condition but not a reduced condition. The recognition of such a conformational Id on F(ab) is important. Because mAb YH206 recognized the carbohydrate on YH206 Ag as well as the peptide on mAb AI206, the conformation on F(ab) of mAb AI206 may mimic the carbohydrate structure on YH206 Ag. In fact, YH206 antibody activity was induced in syngeneic mouse serum immunized with mAb AI206. These observations suggest that the internal image of YH206 carbohydrate Ag is preserved within the conformational Id on F(ab) of mAb AI206.

Adenocarcinoma↗
PubMed1991

Low glucose-1, 6-bisphosphate and high fructose-2, 6-bisphosphate concentrations in muscles of patients with glycogenosis types VII and V.

The level of glucose-1, 6-bisphosphate, a potent allosteric activator of phosphofructokinase, was markedly decreased in muscles of patients with glycogenosis type VII (muscle phosphofructokinase deficiency) and type V (muscle phosphorylase deficiency). Glucose-1-phosphate kinase activity in muscle was virtually absent in a patient with glycogenosis type VII, whereas it was normal in a patient with type V glycogenosis. Glucose-1-phosphate level was increased in type VII glycogenosis, whereas it was decreased in type V glycogenosis. Another activator of phosphofructokinase, fructose-2, 6-bisphosphate was increased in muscles of patients with both types of glycogenosis although it was much higher in type VII than in type V. This finding may be partly related to the difference of fructose-6-phosphate concentrations. The results suggest that phosphofructokinase would contribute to the major glucose-1-phosphate kinase activity in normal human muscle and would also form a kind of self-activating system.

Fructosediphosphates↗
PubMed1991

Animal model of systemic carnitine deficiency: analysis in C3H-H-2 degrees strain of mouse associated with juvenile visceral steatosis.

We analyzed carnitine profiles in C3H-H-2 degrees strain of mouse associated with fatty liver, hyperammonemia and hypoglycemia (Koizumi et al., 1988). Carnitine levels in serum, liver and muscle of mouse with fatty liver were markedly decreased in comparison with those of control mouse (littermates without fatty liver). This is a useful animal model to analyze the role of carnitine in lipid, amino acid and carbohydrate metabolism.

Aging↗
PubMed1991

Evaluation of the electrocardiographic transitional zone by cardiac computed tomography.

The relationship between shift of the transitional zone on the standard 12-lead electrocardiogram (ECG) and anatomical rotation of the heart in one plane was studied by cardiac computed tomography (CT). Based on the position of the transitional zone, 102 subjects were divided into 3 groups: the normal transitional zone (NT) group (31 subjects), clockwise rotation (CWR) group (30 subjects), and counterclockwise rotation (CCWR) group (41 subjects). The left-sided angle between the interventricular septum and horizontal axis of the body (the septal angle) was determined on the cardiac CT and compared among the three groups. The angle was 51.8 degrees +/- 6.8 degrees in the NT group, 38.2 degrees +/- 8.4 degrees in the CWR group, and 64.9 degrees +/- 10.4 degrees in the CCWR group. There were significant differences in the septal angle among the groups (p less than 0.05). The mechanism of CWR and CCWR could be attributed to the septal angle in about two-thirds of the cases (24/30 in CWR and 27/41 in CCWR). However, those not explained by the septal angle amounted to 6 (20%) of the CWR group and 14 (34%) of the CCWR group. Relatively higher positions of the precordial ECG leads, as observed in the vertical heart, appeared to be responsible for CWR in the 6 patients, and left septal fascicular block was suspected to be responsible for CCWR in the 14 patients. These data indicate that about two-thirds of CWR and CCWR can be explained by anatomical rotation of the heart in one plane around the long axis, but other factors appear to be responsible for such electrocardiographic findings in the remaining one-third of cases.

Adult↗
PubMed1991

Antihypertensive effect of dietary calcium loading in angiotensin II-salt rats.

To clarify the hypotensive effect of high dietary Ca intake on salt-sensitive hypertension, 7-wk-old Sprague-Dawley rats, 3.15% Na and/or 4.07% Ca diet loaded, were administered 125 ng/ml of angiotensin II (ANG II) intraperitoneally for 12 days. Compared with control rats (mean blood pressure 108 +/- 2 mmHg), ANG II administration caused hypertension (131 +/- 4 mmHg, P less than 0.05). Na loading enhanced the hypertensive effect of ANG II (161 +/- 4 mmHg, P less than 0.01). Dietary Ca loading did not significantly inhibit the pressor effect of ANG II alone (119 +/- 4 mmHg). However, Ca loading suppressed hypertension in ANG II-salt rats (126 +/- 4 mmHg, P less than 0.01). Plasma total catecholamine (norepinephrine + epinephrine) was increased in ANG II-salt rats (176 +/- 14 vs. 290 +/- 23 pg/ml, P less than 0.05), but Ca loading decreased plasma catecholamine (182 +/- 13 pg/ml, P less than 0.05). In contrast, plasma catecholamine was not significantly different between ANG II-treated rats with and without Ca loading. Ca loading increased serum Ca in ANG II rats (10.9 +/- 0.1 vs. 11.7 +/- 0.1 mg/dl, P less than 0.05) but did not do so significantly in ANG II-salt rats (10.8 +/- 0.2 vs. 10.9 +/- 0.1 mg/dl). Thus Ca loading exclusively ameliorated salt-sensitive hypertension, which was induced with ANG II administration and Na loading in rats, probably through suppression of the increased sympathetic activity. In addition, these effects of Ca loading were not mediated through an increased blood level of Ca.

Angiotensin II↗
PubMed1991

Plasma immunoreactive endothelin-1 concentration in human fetal blood: its relation to asphyxia.

To elucidate the effects of birth stress on immunoreactive endothelin-1 (irET-1) concentrations in fetal blood, we determined irET-1 levels in cord plasma in different modes of delivery associated with or without complications such as asphyxia. The irET-1 concentrations in both the umbilical artery and vein were significantly higher than those found in maternal venous blood at delivery, although there was no significant difference between preterm and full-term infants. When plasma irET-1 concentrations of healthy infants born by vaginal delivery and by cesarean section without labor were compared, the former had significantly (p less than 0.05) higher levels than the latter (15.4 +/- 4.9 pg/mL versus 11.1 +/- 3.1 pg/mL). Furthermore, umbilical venous plasma obtained from vaginally delivered infants complicated by asphyxia showed significantly (p less than 0.001) higher irET-1 levels (28.2 +/- 9.4 pg/mL) than those of nonasphyxiated infants (14.2 +/- 4.5 pg/m). These data suggest that birth stress, especially asphyxia, may contribute to the increase in fetal circulating irET-1 levels.

Asphyxia Neonatorum↗
PubMed1991

Phase image characterization of ventricular contraction in left anterior hemiblock.

We investigated whether or not left anterior hemiblock is present in patients with left axis deviation using first-harmonic Fourier analysis of gated blood-pool images. Gated blood-pool images were taken in 50 patients without contraction abnormality. They included 14 normal subjects, 8 patients with right bundle branch block (RBBB), 20 with left axis deviation (LAD) and 8 with both RBBB and LAD (RBBB + LAD). ECG gated blood-pool scans were acquired in the anterior and "best septal" left anterior oblique projections. First, the phase images were displayed cinematically as a continuous-loop movie. Next, for quantitative analysis of the phase image, the whole left ventricular and left ventricular high lateral regions of interest were drawn. The "regional phase shift" (RPS) was then defined as (RPS = A-a) where "A" is the mean value of the whole left ventricular phase angles and "a" is that of phase angles in the high lateral region. The left ventricular phase changes and the RPSs in the RBBB and LAD groups were similar to those in the normal group. In the RBBB + LAD group, the latest phase changes occurred in the high anterolateral region. The RPSs of this group were significantly lower than those in the other 3 groups (p less than 0.01). These data suggest that left anterior hemiblock might coexist with RBBB in patients with RBBB + LAD, whereas left anterior hemiblock might not exist in the majority of patients with LAD alone.

Bundle-Branch Block↗
PubMed1991

Evaluation with Fourier analysis on radionuclide angiography of viable but stunned myocardium in patients with right ventricular myocardial infarction.

Stunned myocardium of right ventricle was studied by radionuclide angiography (RNA) and Thallium myocardial scintigraphy (TL) in 39 patients with inferior myocardial infarction with and without right ventricular myocardial infarction (RVMI). RNA was performed within 1 week of the onset (acute phase) and after 1 month, when exercise cardiac scintigraphy (EX-TL) was also performed. The ejection fraction (EF) of each ventricle calculated from RNA and the phase and amplitude evaluated visually and quantitatively by Fourier analysis were compared between the acute phase and 1 month after the onset of myocardial infarction. The degree of visualization of right ventricle was examined in EX-TL 1 month after the onset. (1) In RNA obtained in the acute myocardial infarction, abnormalities in the right ventricle (delayed phase or low amplitude image) were observed in 18 (46%) but not in 21 (54%) of the 39 patients (N group). Of those 18 patients, the abnormalities in the right ventricle alleviated in 11 (RVMI-A group) but persisted in 7 (RVMI-B group) in RNA obtained 1 month after the onset. (2) In the acute phase, the right ventricular ejection fraction (RVEF) was 39.4 +/- 10.4% in N group, 30.8 +/- 5.3% in RVMI-A group, and 29.6 +/- 8.9% in RVMI-B group, with significant differences between N group and the other two groups (P less than 0.05) but no significant difference between RVMI-A and RVMI-B groups. (3) After 1 month, RVEF was 40.1 +/- 10.1% in N group, 42.2 +/- 8.4% in RVMI-A group, and 32.2 +/- 9.8% in RVMI-B group, being improved in RVMI-A group and showing a significant difference as compared with RVMI-B group (p less than 0.05). (4) In EX-TL of RVMI-A group, the right ventricle was visible although the uptake of TL was reduced in the entire right ventricle. In RVMI-B group, only part of the right ventricular free wall was visible with defects in the other areas of right ventricle. The sign of RVMI showed improvements in many of the patients after the acute phase, and their condition was considered to have been so-called stunned myocardium, which is a complex of symptoms of reversible myocardial ischemia, rather than RVMI.

Aged↗
PubMed1991

[Assessment of denervated but viable myocardium in patients with myocardial infarction--by myocardial imaging with 201Tl and 123I-MIBG].

The present study assessed sympathetic function in viable infarcted areas of the myocardium following the onset of myocardial infarction. The subjects were 19 patients with myocardial infarction. After exercise on a bicycle ergometer, simultaneous SPECT with Tl-201 and I-123 MIBG was performed. The behavior of MIBG following exercise remains to be clarified, but in the present study MIBG provided images different from those obtained with Tl. While the redistribution of Tl in the infarcted area was observed in 8 of 19 patients, MIBG was absent in the infarcted area in both the initial and delayed scans. In the patient undergoing CABG, the infarcted area showed no MIBG despite the normal perfusion of Tl. The previous proposal that the redistribution of Tl indicates myocardial viability to some extent suggests that the sympathetic function of the area of the myocardium showing the redistribution of Tl decreases even though the area is viable. These findings indicate that after the onset of myocardial infarction, there is a denervated but viable area in the myocardium, despite the viability demonstrated by Tl imaging. They also indicate that concurrent myocardial imaging with MIBG is useful for the detection of such a myocardium.

3-Iodobenzylguanidine↗
PubMed1991

[Medical care system in 21st century].

In a rapidly aging society, the role of medical services to ensure the Japanese people's health has become more and more important. Although it is not easy to forecast precisely 21st century medical services, the existing medical delivery system must be reorganized and improved, recognizing the changes in relative occurrences of diseases, the progress of medical technology, and changes in patient need. It is also necessary to pay adequate attention to the need for medical services in different regions and establish a medical care delivery system based on the need. It is also important to systematize the provision of medical services. The future of the medical care system in the 21st century depends on these approaches.

Adult↗
PubMed1990

[Usefulness of rest-redistribution on thallium myocardial scintigraphy in patients with acute myocardial infarction by SPECT: analysis by bull's eye and unfolded map images].

The purpose of this study was to clarify the clinical significance of rest-redistribution in myocardial scintigraphy (SPECT) in acute myocardial infarction (AMI). Thirty patients with AMI within one week after the onset of attack were studied. SPECT images were obtained 10 min and three hours after injection of 201Tl. Bull's eye images and unfolded map images were prepared. A 201Tl uptake was studied at the infarct and non-infarct sites. Exercise SPECT and radionuclide angiography (RNA) were performed in all patients one month after the onset of AMI, and the findings were compared with clinical and coronary angiographic (CAG) findings. 1. Redistribution of thallium at rest was observed at the infarct sites in nine of the 30 patients. 2. Redistribution at rest was observed at the non-infarct sites in eight patients. 3. Redistribution at rest was observed during exercise SPECT one month after the onset of AMI in patients with redistribution at rest in the acute phase. 4. In patients with redistribution at rest at the infarct site, left ventricular ejection fraction (EF) improved one month after the onset of AMI (delta EF greater than 5%), but it decreased slightly during exercise. 5. Wall motion at the infarct site was not much impaired in patients who showed redistribution at rest at the infarct site. 6. Angina pectoris and recurrence of myocardial infarction were observed more frequently in those with redistribution at rest on SPECT. 7. No characteristic findings were obtained on CAG in those with redistribution at rest.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[An experimental study on change in temporomandibular joint following occlusal changes].

In order to clarify the cause of temporomandibular arthrosis, an experimental study on change in temporomandibular joint resulting from faulty occlusion which is thought to be one of the causes was performed. In this study, macroscopic, radiologic and histopathologic effects of a forced distal positioning of the mandible by occlusal metal splints and loss of posterior teeth in adult Macaca fuscatas were observed. Cephalometric radiograph including posteroanterior and axial projection were taken to determine the individual projection angle for standardized TMJ radiography including lateral oblique transcranial and transpharyngeal projection prior to the experimental procedures. The upper and lower molars of the monkey were extracted and the remaining teeth were prepared and the cast metal splints were adhered in place. They were maintained on their regular diet. Radiographic observation of the joints and macroscopic clinical observation of the occlusion were made individually, immediately after operation, at the 10th, 20th, 40th and 83rd day postoperatively. The monkeys were killed individually at the 10th, 20th, 40th and 83rd day postoperatively, each temporomandibular joints were removed and prepared for contact microradiographic, fluorescent micrographic and histopathologic observations. The results obtained were as follows: 1) Macroscopically, the opening between the upper and lower lateral teeth in full closure was about 2mm, overbite about 2mm in anterior teeth immediately after the splints were adhered in place and molar extraction. The opening between the lateral teeth decreased slowly after the 10th day postoperatively and they were approximating occlusal contact from the distal area of the splints. The whole area of the occlusal surface of the splints came into contact and the mandible positioned posteriorly by the 40th day. 2) Though the cephalometric radiographs in posteroanterior and axial projection did not show the changes of mandible through the whole experimental period, lateral head plates and standardized TMJ radiographs showed posterosuperior positioning of the mandible after 20th day postoperatively, and osseous absorption in the posterior aspect of the condyle at the 83rd day. 3) Contact microradiographic and fluorescent micrographic observations showed osseous remodeling in the neck of condyle at the site of the insertion of the lateral pterygoid muscle, anterior aspect of the retroarticular process and posterior aspect of the condyle.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Periodic leg movements during either epidural or spinal anesthesia in an elderly man without sleep-related (nocturnal) myoclonus.

We report a case of periodic leg movements (PLM) observed in an 86-year-old man during either midthoracic epidural anesthesia or spinal anesthesia. The PLM observed were stereotyped (extension of the big toe in combination with partial flexion of the ankle, knee, and hip lasting 3-5 s) and repetitive (interevent intervals between jerks were 20-40 s) for about 120 and 30 min respectively. The patient was awake but unaware of the PLM unless reminded. The present case was quite similar to sleep-related (noctural) myoclonus (SRM) in every respect except for its occurrence during wakefulness. SRM is more prevalent in the elderly population but its mechanism remains to be elucidated. Previously, we had reported a case of PLM observed in an elderly man with SRM. In our two cases, PLM were seen only while the local anesthetic was acting on the spinal cord; therefore, these anesthesia-related PLM (ARPLM) may suggest that the spinal cord is involved. In particular, we consider that physiological changes seen commonly during non-rapid-eye-movement sleep and a certain phase of anesthesia, such as suppression of the descending inhibitory pathway, and pyramidal tract dysfunction are relevant to ARPLM. In addition, the concomitant alteration of the blood flow in the leg and changes due to aging of the spinal cord may also be involved.

Aged↗