Biomedical subjects

M Yoshimura

Publications and source records attributed to M Yoshimura.

At least 91 records · Page 5Linked to original sources

PubMed1995

[Species difference on binding property of dilazep to erythrocytes and platelets].

The whole blood of human, rabbit and dog spiked with dilazep was fractionated by discontinuous density gradients of Ficoll-Paque, and the species difference of distribution to blood components was elucidated. In order to quantitatively evaluate its blood distribution, the binding property of dilazep to the isolated erythrocytes and platelets was also studied. Dilazep undergoes saturable binding to the erythrocytes. Therefore, the fitting of the data sets to binding models was carried out using the nonlinear least-square method, and binding parameters were calculated. This technique could be also applied to analyze directly the binding parameters for several whole blood components. In human and rabbit, dilazep was bound to the erythrocytes with a high affinity (human, KERY = 0.466 nM; rabbit, KERY = 0.0417 nM), however, the affinity to the erythrocytes in dog was very low. On the other hand, the binding affinity to the platelets decreased in the order of rabbit > dog > human.

Animals↗

PubMed1995

[Study on Alpiniae Fructus. I. Pharmacological evidence of efficacy of Alpiniae Fructus on ancient herbal literature].

Pharmacological effects on anti-diuresis, anti-ulceration, anti-dementia and learning function of 50% ethanolic extract (AO-ext) from Alpiniae Fructus (fruit of Alpinia oxyphylla) removed seed vessel were investigated in order to prove the evidence of the efficacy of Alpiniae Fructus on the ancient herbal literature. AO-ext showed the effects of anti-diuresis, anti-ulceration, anti-dementia and on increase in the learning function in animals. And also, AO-ext exhibited the increasing effect on the serum 11-hydroxycorticosteroid (11-OHCS) level in the above-described experimental animals and in intact and hypophysectomized rats.

11-Hydroxycorticosteroids↗

PubMed1995

Effect of 5,6,7,8-tetrahydroneopterin on the bovine endothelial cell injury induced by cumene hydroperoxide.

Neopterin is an 2-amino-4-hydroxypteridine derivative and a precursor of biopterin, which is derived from guanosine triphosphate. Previously, we have reported that 5,6,7,8-tetrahydroneopterin (NPH4), a reduced form of neopterin, possesses an antioxidant activity in various systems. In this study, we investigated the activity in more detailed manner and discussed the possible applications of this antioxidant. Analysis by electron spin resonance spectrometry indicated that NPH4 scavenged superoxide anion radicals and hydroxyl radicals as well. Moreover, NPH4 protected the rat brain homogenate from autoxidation. Next, we examined the effect of NPH4 on the cell injury induced by cumene hydroperoxide (CHP) in cultured bovine artery endothelial cells. The activity of lactate dehydrogenase, a marker enzyme of cell injury, was elevated by CHP in a dose-dependent manner, and this elevation was dose-dependently suppressed by NPH4. The elevation of lipid peroxide content was also inhibited by NPH4 in the same fashion. These data suggest that NPH4 would be effective against various diseases whose pathogenesis is active oxygen-related.

Animals↗

PubMed1995

Mechanism of hypertension induced by chronic inhibition of nitric oxide in rats.

In order to clarify the mechanism of hypertension induced by a nitric oxide (NO) synthase inhibitor, L-NG-nitro-L-arginine (LNNA), metabolites of NO, catecholamines, and hemodynamic parameters were measured during 7 days of oral administration of LNNA in rats. Control rats received either L-arginine (L-Arg) or the vehicle. systolic blood pressure, measured by the tall-cuff method was elevated throughout the period of LNNA administration, but that in the two control groups was not influenced by treatment. Heart rate decreased on the second day only in LNNA-treated rats. Although L-Arg treatment had no influence, LNNA markedly decreased the plasma level and the urinary excretion of nitrate ions (NO-3). Urinary excretion of noradrenaline was significantly decreased on the second day of LNNA administration and returned to the control level thereafter. When hemodynamic changes were measured by using radioactive microspheres, LNNA was found to increase blood pressure by markedly increasing total peripheral resistance. Cardiac output was decreased by LNNA. L-Arg, again, did not influence the hemodynamic variables as compared with the vehicle control group. The regional vascular resistance index was increased by LNNA in many tissues and organs, except the brain and the heart. Regional blood flow, on the other hand, was significantly decreased only in the liver and skin by LNNA. The marked reduction in NO3- in urine by LNNA-treatments may indicate that the measured NO3- is exclusively of endogenous origin, and that inhibition of NO production causes elevation of blood pressure by constricting peripheral arteries. Sympatholytic responses by the baroreceptor reflex were thereby evident only on the second and the third days, which was indicated by bradycardia and suppression of noradrenaline excretion into urine. These results indicate that the inhibition of NO synthase actually decreases production of endogenous NO, and that the hypertension caused by decreases in NO production is due to elevation of total peripheral vascular resistance.

Animals↗

PubMed1995

Systemic magnesium deficiency disclosed by magnesium loading test in patients with essential hypertension.

The present study was designed to determine whether magnesium (Mg) deficiency is present in patients with essential hypertension. We measured the retention of an intravenously administered Mg load (0.2 mmol/kg MgSO4 over 4 h), and serum and erythrocyte Mg concentrations in 17 inpatients with essential hypertension and in 15 normotensive controls. There was no significant difference between the two groups in erythrocyte Mg concentration (normotensives vs., hypertensives: 2.0 +/- 0.5 vs. 2.1 +/- 0.4 mmol/l cells), serum Mg concentration (normotensives vs. hypertensive: 2.1 +/- 0.2 vs. 2.1 +/- 0.2 mg/dl), or in urinary Mg excretion (normotensives vs. hypertensives: 65.8 +/- 25.5 vs. 73.7 +/- 26.7 mg/day). However, Mg retention was significantly higher in hypertensives than in normotensives (normotensives vs. hypertensives: 31.8 +/- 12.1 vs. 41.9 +/- 13.3%). These results suggest that a systemic Mg deficiency, which is undectectable by serum or erythrocyte Mg determination, may exist in patients with essential hypertension.

Adult↗

PubMed1995

Does dopamine act on myocardial cells?

We examined the electrophysiological effects of dopamine on the single myocardial cells isolated from the rat and rabbit heart. Dopamine at a concentration of 1 or 10 microM did not affect the L-type Ca2+ current (ICa) or the transient outward current (ITO) in rat ventricular, rabbit atrial, ventricular, and sinoatrial node cells. It did not induce any detectable change in the action potential configuration of the rabbit ventricular cells either. We conclude that dopamine does not directly act on myocardial cells at least in terms of the electrophysiological properties.

Action Potentials↗

PubMed1995

Urinary excretion of free dopamine and digoxinlike substances correlates with endogenous secretion of insulin in normotensive adults, but not in hypertensive subjects.

We investigated whether urinary excretion of free dopamine is related with the humoral factors which affect Na+, K+ ATPase activity in the kidneys. Subjects were 51 adults admitted in a hospital without renal insufficiency: they were divided into normotensive (n = 36, 60 +/- 3 years old, 122 +/- 3/73 +/- 2 mmHg) and hypertensive groups (n = 15, 65 +/- 5 years old, 157 +/- 6/91 +/- 2 mmHg). Urinary excretion of free dopamine was significantly and positively correlated with urinary excretion of C-peptide immunoreactivity of insulin (CPR) (r = 0.451, p = 0.014) in normotensive subjects, but not in hypertensive subjects (r = 0.155, p = 0.668). Urinary excretion of endogenous digoxinlike substances (EDLS) was also significantly and positively correlated with urinary CPR (r = 0.500, p = 0.006) in normotensive subjects, but not in hypertensive subjects (r = 0.275, p = 0.363). In normotensive subjects, urinary excretion of free dopamine and EDLS may be regulated at least in part by insulin secreted endogenously. In hypertensive subjects, however, this regulatory mechanism of the diuretic factors, such as insulin, EDLS and dopamine, is thought to be deranged, which might result in decompensation of a diuretic and antidiuretic balance leading to blood pressure elevation.

Adult↗

PubMed1995

Diagnostic significance of dopamine estimation using plasma and urine in patients with adrenal and renal insufficiency, renal transplantation and hypertension.

Although free and conjugated dopamine (DA) constitute most of the plasma and urine catecholamine pool, the diagnostic significance of DA estimation for the evaluation of illness is not clear. We evaluated the clinical utility of DA estimation by measuring free and conjugated DA in patients with various illness. Patients with adrenal insufficiency did not show decreases in DA concentrations but did demonstrate reductions in free and conjugated plasma adrenaline (Ad). Patients with established stage of essential hypertension exhibited decreased plasma concentrations of free and conjugated DA, although they were hyperadrenergic. In patients with chronic renal insufficiency and failure, the free DA concentration in the urine decreased depending on the severity of renal impairment. Conversely, plasma concentrations of conjugated DA are higher in patients with chronic renal failure than in normal subjects. The high plasma concentrations of conjugated DA decreased dramatically following hemodialysis and renal transplantation. Urinary free DA excretion increased markedly following renal transplantation. In conclusion, the estimation of the free and conjugated DA in plasma and urine is clinically useful for the diagnosis of adrenal insufficiency, essential hypertension, and renal insufficiency and failure. It also can be used to monitor the effectiveness of hemodialysis and renal transplantation.

Adrenal Insufficiency↗

PubMed1995

Effectiveness of an inactivated goose parvovirus vaccine in Muscovy ducks.

With goose parvovirus (GPV) strain IH, an inactivated vaccine was prepared from allantoic fluid of embryonating Muscovy duck eggs inoculated with GPV. The response to vaccination was measured by virus neutralizing antibody titer against GPV. Offsprings from the vaccinated flock were introduced in a farm in which GPV infection had been experienced and examined for resistance to exposure to GPV. The results showed that the intramuscular vaccination to Muscovy ducks at any age stimulated significant virus neutralizing antibody levels, and that more than 90% Muscovy ducklings from the vaccinated parent flock survived after the exposure to GPV. Muscovy ducklings that passively possessed high level virus neutralizing antibodies also could respond to the vaccination and the induced antibodies remained for more than 2 months.

Aging↗

PubMed1995

Thyroid stimulating antibody in sera of Graves' ophthalmopathy patients as a possible marker for predicting the efficacy of methylprednisolone pulse therapy.

Nine patients with Graves' ophthalmopathy (GO) were treated with intravenous methylprednisolone pulse therapy and followed up by ophthalmological assessment, magnetic resonance imaging, and thyroid-associated autoantibody (thyroid stimulating antibody (TSAb), TSH binding inhibitor immunoglobulins (TBII), and anti-eye muscle antibody (EMAb)). Ophthalmological assessment was performed by the ophthalmopathy index (OI) which was made on the basis of the system recommended by the American Thyroid Association Committee. EMAb was expressed as the ratio of density of the 64 kDa band of eye muscle membrane to that of 92 kDa non-specific band found with all normal sera when assessed by western blotting. Five patients with mild ophthalmopathy (OI < 4) did not show progressive improvement in OI. Three of 4 patients with severe eye disease (OI > 4) showed a progressive and distinct improvement in OI. These 3 patients had high TSAb levels before methylprednisolone pulse therapy. One patient with severe ophthalmopathy did not respond to this pulse therapy; this patient's TSAb was negative. A significant positive correlation was observed between the activity of TSAb before treatment and the improvement in OI (delta OI) (r = 0.86, P < 0.01, n = 9). The relationship between delta OI and EMAb did not reach significance. These results suggest that TSAb in sera of GO patients can be a useful marker for predicting the efficacy of methylprednisolone pulse therapy.

Adolescent↗

PubMed1995

[Renal arterial disease-induced tubulo-interstitial lesions].

Renal arterial disease-induced tubulo-interstitial lesions described in this chapter include benign arterio- and/or arteriolo-sclerotic and malignant nephrosclerosis, renal infarction and renal cortical necrosis. In these conditions renal glomeruli as well as tubules are always involved, and consequent loss of nephrons, or renal parenchyma results in interstitial fibrotic changes. The parenchymal lesions have a spectrum from slowly progressive atrophy and loss to necrosis of abrupt onset and disappearance of glomeruli and tubules. As for glomerular reactions to the ischemia, the intermediate type consisted of mesangial degeneration and epithelial cell proliferation described as "alterative glomerulitis" is noteworthy. Briefly, in renal arterial diseases, glomeruli are rather variably involved than tubules and loss of the parenchyma results in interstitial fibrosis.

Arteriosclerosis↗

PubMed1995

Estimation of age from image processing of soft X-ray findings in Japanese male thyroid cartilages.

A method was developed for estimating the age at death based on image processing of soft X-ray pictures of thyroid cartilage from Japanese males. Data for 501 individuals were used to derive equations for this determination. Prior to image processing, gross morphological findings were used for estimation. Soft X-ray pictures indicated ossification with age and one index for image processing was introduced. The exponential function was applied to age estimation.

Adult↗

PubMed1995

Estimation of age from soft X-ray findings of Japanese females thyroid cartilages.

A method for estimating the age at death using the image processing of soft X-ray pictures of the thyroid cartilages of Japanese females was examined. The soft X-ray pictures showed increasing ossification with age. One index for image processing was introduced. It is ossification rate (OSFR). Corresponding to this index, one age estimation equation was obtained. This age estimation equation showed accuracies of 60% or more for the age range of +/- 5 years and about 80% for the age range of +/- 8 years.

Adult↗

PubMed1995

Autopsy cases of giant heart during the past ten years in Osaka (1985-1994).

We collected data from 30 autopsied cases, in which the heart weight were 800 g or more (maximum 1,300 g), at the Osaka Medical Examiner's office, for past 10 years. Among these cases, the cause of death was cardiac failure in 17 cases (56.7%), followed by pulmonary diseases (3 cases, 10.0%), cerebral infarction (3 cases, 10.0%), and aortic rupture (2 cases, 6.6%). The mean weight of the giant hearts was 880 g (about 77% of the cases) and 4 cases (13%) had 1,000 g or more. The mean height of the giant heart victims was close to the standard level, and thus the mean level of the ratio of heart weight to height were about 2.5 times higher than the standard levels. The liver weights were also greater by 500-1,000 g than the standard levels.

Adult↗

PubMed1995

[Combination therapy of doxifluridine, pirarubicin and cisplatin for human gastric cancers implanted in nude mice].

In the preclinical study of a new combination therapy for gastric cancer, dFTP, consisting of doxifluridine (5'-DFUR), pirarubicin (THP) and cisplatin (DDP) as a modification of conventional FAP regimen (5-fluorouracil+Adriamycin+DDP), we compared antitumor and toxic effects of two sequential treatment schedules, single injection of DDP before or after 4 daily administrations of 5'-DFUR, on 5 strains of human gastric cancer bearing nude mice. Results indicated that both schedules of the dFTP regimen had potent antitumor effects. There was no significant difference between them. On the other hand, in terms of the host toxicity as observed by body weight loss, the post-DDP schedule was significantly less toxic than pre-DDP. These results suggest that dFTP regimen (post-DDP schedule) may be useful for clinical treatment of gastric cancers.

Adenocarcinoma↗

PubMed1995

[Short somatosensory evoked potentials in patients with Fukuyama type congenital muscular dystrophy--a comparison with CT and MRI findings].

Seven patients with Fukuyama type congenital muscular dystrophy were studied. Low density areas (LDs) in the cerebral white matter on cranial CT were present in all 4 patients younger than 13 years of age and in 1 of 3 adult patients. LDs corresponded to low signals on T1 weighted MRI image and high signals on T2 weighted MRI image. The follow-up MRI showed a decreased tendency of the abnormal signals in 2 patients. Short somatosensory evoked potentials (SSEPs) in two infants, aged 4 months and 8 months, showed absent or depressed N1 amplitudes and delayed interpeak latencies from P3 to N1. N1 amplitudes increased on follow-up studies. SSEPs of five patients, who were older than 2 years of age, showed normal N1-P3 latencies. Amplitude of N1 was low in 2 patients with LD. Since the absent or depressed amplitude and delayed latency of N1 improved with the decrease of abnormal signals on MRI, we considered that N1 abnormalities show delayed myelination.

Adolescent↗

PubMed1995

[Postoperative interstitial pneumonia in primary lung cancer patients--its causes and management].

Eight patients who developed interstitial pneumonia after surgery for primary lung cancer were reviewed to investigate its causes and the key points in treatment. These patients accounted for 1.8% of 633 operated lung cancer patients at our institution over the last 9 years. Risk factors such as bilateral recurrent laryngeal nerve palsy, preoperative chemoradiotherapy, and extensive mediastinal involvement were present in all of them. Pneumonia developed on the nonoperated side in all patients between the 2nd and 45th postoperative day (mean: 18 days). In most of the patients, faint reticular shadows initially appeared in the lower lobe of the nonoperated lung, rapidly spread to the upper lobe, and finally affected the whole lung. Among these eight patients, the initial five patients died because steroids were only administered after the pneumonia had become widespread, whereas the last three patients received early steroid therapy and were saved. The findings that 1) this pneumonia originated from the lower lobe of the nonoperated lung where blood flow is highest postoperatively, 2) the eosinophil count increased just before the onset of pneumonia, and 3) early steroid therapy and immunosuppressive therapy were effective suggest that an allergic or autoimmune mechanism may play some role in its development. When characteristic reticular shadows appear in the lower lobe on the nonoperated side in a lung cancer patient, even if not associated with any symptoms, an early diagnosis of interstitial pneumonia and initiation of steroid therapy is mandatory to ensure survival.

Aged↗

PubMed1995

[Suppression of lung metastasis of B16 mouse melanoma cells by introduction of N-acetylglucosaminyltransferase III gene].

The beta 1-6 structure of N-oligosaccharides, formed by beta 1-6 N-acetylglucosaminyltransferase (GnT-V), is associated with metastatic potential. We established a highly metastatic subclone, B16-hm, from low metastatic B16-F1 murine melanoma cells. Introduction of the gene for beta 1-4 N-acetylglucosaminyltransferase (GnT-III) into B16-hm murine melanoma cells reduced the level of beta 1-6 structure by competing for the substrate, resulting in the suppression of lung metastasis in both syngeneic and nude mice, decreased invasiveness into the matrigel, and inhibition of cell attachment to collagen and laminin without affecting cell growth. The gene transfection altered the N-oligosaccharides of membrane glycoproteins, as measured by L-PHA and E-PHA binding. Our results demonstrated a causative role for beta 1-6 branches in the metastasis by gene transfection.

Animals↗