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Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 703 records · Page 39Linked to original sources
PubMed1993

A case of antirabies inoculation encephalitis with a long clinical course.

In 1950, a 24-year-old man developed gait disturbance, incontinence of urine and increasing lethargy a week after a course of antirabies vaccination. He was diagnosed as having post-rabies vaccination encephalitis and had been in hospital for 37 years before he died in 1987. This is one of the rare cases in which the course of this disease was traced for an exceptionally long period. His personality began to deteriorate at an early stage of the illness, but his intellectual faculties seemed to be maintained rather well until a few years prior to his death. A neuropathological study revealed disseminated, patchy and somewhere perivascularly located demyelinated lesions in the cerebral white matter. Inflammatory lymphocytic infiltration was also remarkable in the CNS regions. But while the superimposed lesions due to convulsive attacks, traumatic contusion and terminal anoxia were remarkable, the whole aspect of neuropathological changes in rabies inoculation encephalitis cannot be observed.

Adult↗
PubMed1993

Assessment of body composition measured by bioelectrical impedance in children.

Bioelectrical impedance methods have been found to be a valid and reliable way of estimating per cent body fat (%BF) in adults. We applied them to healthy children and compared them with conventional anthropometry methods. One thousand two hundred and sixteen children participated in this study. Impedance and skinfold thickness were measured, and %BF was estimated using these values. Bodyweight and height were measured, and per cent obesity (%OB) and body mass index (BMI) were obtained. The values of %BF by the bioelectrical impedance method (%BFi) were 8.6 +/- 4.0% in the junior male group, 14.2 +/- 2.8% in the junior female group, 7.9 +/- 4.7% in the senior male group and 16.1 +/- 2.9% in the senior female group. The %BFi correlated strongly with skinfold thickness, %OB and BMI. Thus %BFi correlated strongly with variables from conventional methods. It was concluded that it is a reliable way of assessing lipid storage in children.

Adolescent↗
PubMed1993

Effects of KRN2391, nicorandil and diltiazem on the changes in the electrocardiogram caused by endothelin-1 in anaesthetized rats.

1. The effect of KRN2391, a novel vasodilator, on the changes of electrocardiogram caused by endothelin-1 (ET-1) was studied in anaesthetized rats and compared with the effects of nicorandil and diltiazem. In addition, the effect of KRN2391 on the action potential of guinea-pig papillary muscle was studied. 2. The intracoronary administration (i.c.) of ET-1 (5 micrograms) induced not only ST segment elevation of the electrocardiogram due to contraction of the coronary artery, but also arrhythmias involving atrioventricular block (A-V block), ventricular premature contraction (VPC) and ventricular fibrillation (VF), and resulted in death in most animals. However, the administration of methacholine (3 micrograms, i.c.) produced ST segment elevation alone without developing arrhythmias. 3. Pretreatment with intravenous administration of KRN2391 (30 micrograms kg-1) inhibited the ST segment elevation and the development of arrhythmias induced by ET-1, and decreased the incidence of death. 4. Nicorandil (1000 micrograms kg-1) prevented the ST segment elevation without suppression of the occurrence of VF. Diltiazem (100 micrograms kg-1) suppressed both the ST segment elevation and the occurrence of VF but not other arrhythmias. Nicorandil at 3000 micrograms kg-1 and diltiazem at 300 micrograms kg-1 produced not only a suppression of ST segment elevation and VF incidence but also a decrease in the occurrence of arrhythmias. These doses of nicorandil and diltiazem produced a decrease in death in a dose-dependent manner. 5. KRN2391 (10 and 30 micrograms kg-1), nicorandil (1000 and 3000 micrograms kg-1) and diltiazem (100 and 300 micrograms kg-1) significantly decreased mean blood pressure in a dose-dependent manner. Heart rate was decreased by nicorandil (3000 microg kg-1) and diltiazem (100 and 300 microg kg-1) but was not affected byKRN2391 (10 and 30 microg kg-1).6. KRN2391 (30 microM) significantly shortened the action potential duration of guinea-pig ventricle at 50% and 90% repolarization (APD50 and APD90). The effect of KRN2391 was inhibited by a K+channel blocker, glibenclamide (30 microM).7. These results suggest that the occurrence of ST segment elevation and arrhythmias induced by ET-1 are due to a dual direct action on both coronary vascular smooth muscle and myocardium. Therefore,the protective effects of KRN2391, nicorandil and diltiazem on ET-l-induced heart disorders appear to be due to their direct actions on coronary vascular smooth muscle and the myocardium.

Action Potentials↗
PubMed1993

Dissimilarity in the mechanisms of action of KRN2391, nicorandil and cromakalim in canine renal artery.

In the present study, we examined the mode of action of KRN2391 (N-cyano-N'-(2-nitroxyethyl)-3-pyridinecarboximidamide monomethanesulphonate) in isolated canine renal artery compared with those of nicorandil and cromakalim. KRN2391 (10(-8)-3 x 10(-5) M), nicorandil (10(-7)-3 x 10(-4) M) and cromakalim (10(-8)-3 x 10(-5) M) relaxed renal arteries contracted by 25 mM KCl in a concentration-dependent manner. KRN2391-induced relaxation was inhibited by methylene blue (10(-5) M) and glibenclamide (10(-6) M). Nicorandil-induced relaxation was inhibited by methylene blue, but not by glibenclamide. The concentration-relaxation curve for cromakalim displayed a rightward parallel shift in the presence of glibenclamide. In the control observation, KRN2391 and nicorandil also produced full relaxation, but cromakalim did not. The present results suggest that KRN2391 acts as both a nitrate and a potassium channel opener, and nicorandil acts only as a nitrate and only in canine renal artery.

Animals↗
PubMed1993

In-vitro permeability to salicylic acid of human, rodent, and shed snake skin.

In-vitro permeability to salicylic acid of human, rodent, and shed snake skin has been examined for the purpose of selecting model membranes for human skin corresponding to different anatomic sites, since a marked regional variation is suggested among the different sites. The greatest permeability to salicylic acid was observed in the scrotum, that of the sole was negligible. The cheek, neck, and inguinal skin seemed more permeable than the breast, back, thigh, lower leg, or foot skin. Shed snake and skin of hairless rat were found to show similar permeability to human breast and thigh skin. Wistar rat and nude mouse skin showed similar permeability to human cheek, neck, and inguinal skin.

Animals↗
PubMed1993

Callosal atrophy with reduced cortical oxygen metabolism in carotid artery disease.

BACKGROUND AND PURPOSE: In cerebrovascular disease, brain atrophy may be a reflection of ischemic changes. Minor changes that are not detectable as infarction on computed tomography may result in atrophy with metabolic depression. We evaluated the relation between size of the corpus callosum and cerebral cortical oxygen metabolism in carotid artery disease. METHODS: We used magnetic resonance imaging and positron emission tomography to evaluate 13 right-handed male patients with transient ischemic attacks or minor strokes and unilateral internal carotid artery occlusive disease, two with stenosis and 11 with occlusion. Computed tomography showed only minor subcortical abnormalities in the affected hemisphere. Midsagittal corpus callosum areas on T1-weighted magnetic resonance images, white matter lesions on T2-weighted images, and the cerebral metabolic rate of oxygen measured by the oxygen-15 steady-state technique were analyzed. RESULTS: Compared with 13 age- and sex-matched control subjects showing the same degree of white matter areas of high intensity, the patients had significantly decreased callosal areas. The degree of corpus callosum atrophy was significantly correlated with the mean cortical oxygen metabolic rate. The same tendency was also found in five patients without infarcts on computed tomography. However, neither the callosal area nor the hemispheric metabolic rate was correlated with the extent of white matter lesions. CONCLUSIONS: These findings indicate that atrophy of the corpus callosum occurs in association with a decrease in cortical oxygen metabolism. Corpus callosum atrophy may be a useful morphological index that reflects the cerebral cortical metabolic state in carotid artery occlusive disease.

Aged↗
PubMed1993

Macrophage colony-stimulating factor regulates both activities of neutral and acidic cholesteryl ester hydrolases in human monocyte-derived macrophages.

Macrophage colony-stimulating factor (M-CSF) regulates cholesterol metabolism in vivo and in vitro. We studied the effects of M-CSF on enzyme activities of acidic cholesteryl ester (CE) hydrolase, neutral CE hydrolase, and acyl-coenzyme A:cholesterol acyltransferase (ACAT), all of which are involved in cellular cholesterol metabolism in macrophages. During the differentiation of monocytes to macrophages, these enzyme activities were induced and further enhanced in response to M-CSF. M-CSF (100 ng/ml) enhanced acidic and neutral CE hydrolase and ACAT activities by 3.2-, 4-, and 2.3-fold, respectively, in the presence of acetyl LDL. The presence of acetyl LDL influenced these enzyme activities. ACAT and acidic CE hydrolase activities were increased and neutral CE hydrolase activity was decreased, indicating that these enzymes are regulated by intracellular cholesterol enrichment. M-CSF increased the ratios of acidic CE hydrolase to ACAT activity and of neutral CE hydrolase to ACAT activity. The results suggest that M-CSF enhances net hydrolysis of CE by stimulating the two CE hydrolases to a greater extent than ACAT, and M-CSF may reduce the rate of atherogenesis.

Base Sequence↗
PubMed1993

Effect of KRN2391, a novel vasodilator, on various experimental anginal models in rats.

The antianginal effect of KRN2391, N-cyano-N'-(2-nitroxyethyl)-3-pyridinecarboximidamide monomethanesulfonate, on various anginal models in rats was compared with those of nifedipine and nicorandil. Angina pectoris was induced by methacholine or isoproterenol, and the change in the ST-segments in the electrocardiogram (ECG) was used as the parameter to indicate angina pectoris. The intracoronary administration of methacholine (3 micrograms) produced an elevation in the ST-segment of the ECG. This ST-elevation was inhibited by the intravenous administration of KRN2391 (30 and 100 micrograms/kg), nifedipine (100 and 300 micrograms/kg) and nicorandil (1000 and 3000 micrograms/kg). The administration of isoproterenol (10 micrograms/kg/min, i.v.) produced a depression of the ST-segment of the ECG. The intravenous administration of KRN2391 (100 micrograms/kg), nifedipine (100 micrograms/kg) and nicorandil (3000 micrograms/kg) inhibited the ECG changes induced by isoproterenol. These results suggest that KRN2391 exerts a potent protective effect on angina pectoris models compared with nifedipine and nicorandil. KRN2391 appears to be useful as an antianginal drug.

Angina Pectoris↗
PubMed1993

Spontaneous mutation rates in null and band-morph mutations of enzyme loci in Drosophila melanogaster.

Spontaneous mutations were accumulated for a total of 1,678,388 allele-generations in several hundred replicate second chromosome lines. These lines were compared of a Cy chromosome and one of three different lethal bearing chromosomes from natural populations. Electrophoretic mobility and/or activity change was screened for seven enzyme loci. Forty-four null mutations were detected, but no band-morph mutations were observed. There is significant variation in null mutation rate among enzyme loci and among lethal chromosomes. This may be attributable to differences in the distribution of transposable elements among the lines. The band-morph mutation rate is pooled with previous results and becomes 7.48 x 10(-7) with a 95% confidence limit of 2.04 x 10(-7) to 1.91 x 10(-6) per locus per generation. Similarly, the pooled null mutation rate becomes 1.30 x 10(-5) with 95% confidence limit of 1.15 x 10(-5) to 1.52 x 10(-5) per locus per generation.

Animals↗
PubMed1993

Sex difference in free erythrocyte protoporphyrin (FEP) level. IV. Sex difference in FEP level in rabbits exposed to lead.

An experimental study on Japanese White (JW) rabbits was conducted to clarify the sex difference in FEP level. Male and female rabbits (n = 14 of each sex) were used. The animals of the same sex were divided into 3 groups; i.e., control group (5% glucose solution only, n = 4), low lead dose group (Pb 0.4 mg/kg.BW, n = 5) and high lead dose group (Pb 2 mg/kg.BW, n = 5). Lead was injected intravenously twice a week for 5 wk. The following parameters were determined once a week for 5 wk: blood lead (Pb-B), FEP, Ht, Hb, erythrocyte ALA-D activity, erythrocyte pyrimidine 5'-nucleotidase (P5N), urinary coproporphyrin (CP-U), urinary delta-aminolevulinic acid (ALA-U), iron in serum (Fe-S), and serum GOT and GTP. Average levels of FEP in female rabbits were higher than those in males between the 1st and 3rd week after the lead injection in the low lead dose groups, and in the final week in the high lead dose groups. In the periods without lead injection, the average levels of FEP in the female groups were not significantly higher than the corresponding levels in the male groups in every week except in the first week in the control. However, the mean of FEP levels in all female rabbits without Pb treatment was higher than that in male rabbits (t-test). By the analysis of variance for the gains of FEP from the initial value, only the low lead dose group showed a significant sex difference (female > male); that is, the female group tended to increase when compared with the male group. Furthermore, the week when FEP began to increase in the female groups was earlier than that in the male groups in the low lead dose group. In the high lead dose group, both sexes reacted to the lead exposure from the same early week. As for the parameters of anemia, the average levels of Ht and Hb tended to be lower in females than in males, but Fe-S levels were not affected by lead in both sexes and no consistent sex difference could be observed. By lead exposure, ALA-D and P5N were inhibited, and ALA-U was increased, but these parameters showed no evident sex difference. The average levels of CP-U tended to be higher in females than in males in the administration of low lead dose and to be inversely higher in males than in females in the administration of high lead dose.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Limited adaptation in chronically hypertrophied hearts from aortic constricted rats: increased inhomogeneity in cross-sectional area of cardiomyocytes and intercapillary distance.

To study the sequential changes of myocardial structure in pressure-overloaded heart, rats were subjected to banding of ascending aorta at 8 weeks of age, and electron-microscopical morphometry was performed at weeks 1, 2, 4, 8, 16, and 24 postoperatively. Not only was the cross-sectional area of cardiomyocyte greater in banded rats but the degree of inhomogeneity increased in correspondence with development of hypertrophy. Intercapillary distance was significantly longer in banded rats than in controls. In banded rats, the distance around larger-than-normal cells (with a cross-sectional area exceeding 600 microns 2) was significantly longer than that around normal-sized cells (with a cross-sectional area under 600 microns 2) at 4, 16, and 24 weeks following surgery. Morphologically, intracellular capillaries were shown to develop; however, single or several necrotic cells were observed in 8- to 16-week banded rats and were attributed to acute ischemia. In 24-week banded rats, advanced interstitial fibrosis as well as collapsed intracellular capillaries were observed.

Acclimatization↗
PubMed1993

Pineocytoma with intratumoral hemorrhage following ventriculoperitoneal shunt--case report.

A 58-year-old female with pineocytoma developed intratumoral hemorrhage after ventriculoperitoneal shunting for hydrocephalus. Neurological examination revealed Parinaud's sign and papilledema. Computed tomography and magnetic resonance (MR) imaging revealed a pineal neoplasm and obstructive hydrocephalus. Serum and cerebrospinal fluid levels of human chorionic gonadotropin, alpha-fetoprotein, carcinoembryonic antigen, and placental alkaline phosphatase were negative or within normal limits. MR images after the ventriculoperitoneal shunting disclosed intratumoral hemorrhage and markedly smaller ventricles. The tumor was totally removed via the occipital transtentorial approach and was diagnosed histologically as a pineocytoma with astrocytic differentiation. The tumor probably shifted away from the surrounding structures following the marked reduction in ventricular size after ventriculoperitoneal shunting, resulting in changed venous circulation in the tumor and the formation of intratumoral hematoma.

Brain↗
PubMed1993

Recovery of the vestibular function after vestibular neuronitis.

We performed steroid therapy on 34 cases with vestibular neuronitis and compared them with 77 patients not subjected to this therapy to examine the role of recovery of their vestibular function. Since no relation was noted between use of steroid and changes in subjective symptom of dizziness, the use of steroid is likely to facilitate the disappearance of spontaneous nystagmus in the early recovery stage. Canal paralysis recovered significantly by steroid and in cases of slight and moderate paralysis at the onset, recovery was more significant. Steroid therapy is argued to be effective for the recovery of vestibular function in cases of vestibular neuronitis.

Administration, Oral↗
PubMed1993

A clinical observation of benign paroxysmal positional vertigo (BPPV) after vestibular neuronitis (VN).

We observed 9 cases of BPPV developed after vestibular neuronitis. The interval between the onset of BPPV and vestibular neuronitis ranged from 2 weeks to 20 years. All cases were examined for critical head position which provoked vertigo, non-gaze nystagmus, positional and positioning nystagmus and caloric nystagmus. No characteristic signs and symptoms could be observed. The function of the posterior canal is thought to be necessary to provoke positional vertigo. Thus in BPPV after vestibular neuronitis the function of the posterior canal would presumably have been preserved to some degree. The first possibility is that the function of the posterior canal was not impaired in spite of the damage of the lateral canal. The fact that each canal differs in involvement in vestibular neuronitis may be explained by the difference in the blood supply or the innervation between lateral and posterior canals. If only the artery or nerve which is related to the lateral canal is damaged and the artery or nerve to the posterior canal is not involved, then the function of the posterior canal is preserved. So BPPV may occur soon after the disappearance of severe vertigo. The second possibility is that if the posterior canal had been damaged together with the lateral canal and the functions are recovering, BPPV may occur some time after the onset of vestibular neuronitis. The locus of vestibular neuronitis is in the peripheral vestibular system and the extent and degree of the lesion vary, which may explain why there can be time difference of the recovery between the two canals.

Adult↗
PubMed1993

[Transcranial Doppler sonography in acute intracranial hypertension model--usefulness of pulsatility index].

The authors studied intracranial hemodynamics in experimental animals (Macaca Fuscatus) with acute intracranial hypertension by use of transcranial Doppler (TCD) ultrasound. The blood mean flow velocity in the middle cerebral artery (MCA-FV) and pulsatility index (PI) was recorded using TCD ultrasound (TC2-64, EME) as in the clinical study. Acute intracranial hypertension was produced to determine the correlation of MCA-FV with intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in 11 monkeys, and the correlation of PI with ICP and CPP in 7 monkeys. ICP was elevated by infusing 0.1-0.2 ml/min of saline into the balloon using infusion pump. ICP was raised until maximum level. Changes of MCA-FV, PI, ICP and CPP were evaluated until the CPP of 0mmHg. There was a significant correlation between MCA-FV and ICP (p < 0.01) as well as between MCA-FV and CPP (p < 0.01) in all 11 monkeys. There was also a significant correlation between PI and ICP (p < 0.01) and between PI and CPP (p < 0.01) in 7 monkeys. PI increased markedly when ICP was 80mmHg or greater or when CPP was 60mmHg or less. ICP was always above 80mmHg when PI was above 1.2. All PI values were above 1.0 when CPP was 40mmHg or less. Thus, we could not estimate the absolute values of ICP or CPP from MCA-FV and PI. It seems possible, however, to follow changes in intracranial hemodynamics at the time of increased ICP if MCA-FV and PI are measured continuously while paying attention to factors influencing MCA-FV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Malignant astrocytoma with extracranial metastases: a case report.

A 41-year-old man was referred to this hospital after being diagnosed as suffering from malignant astrocytoma. In spite of two operations and subsequent chemoradiation therapy, the patient died 20 months after the onset of disease. At autopsy, the authors found skin invasion of tumor at left temporal region, softening of the brain and subarachnoid hemorrhage at the base of the brain. Yellowish-white bulging lesions were found at the bottom of left lung, diaphragm and parietal pleura. Histologically, primary lesion showed features of anaplastic malignant astrocytoma. Subarachnoid dissemination was noted at the base of the brain and in the spinal canal. Invasion into the vessels were observed both at the primary site and at the base of the brain. Glial fibrillary acidic protein positive spindle-shaped tumor cells proliferation was seen in the metastatic lesions. This case was diagnosed as malignant astrocytoma with remote extracranial metastases.

Adult↗
PubMed1993

[Metastatic lung cancer presenting with multiple thin-walled cavity-like shadows in a young adult with gallbladder cancer].

A rare case of metastatic lung cancer presenting with multiple thin-walled cavity-like shadows in a young adult with gallbladder cancer is reported. A 30-year-old man consulted our hospital with fever, cough, and general malaise. His chest X-ray film and computed tomogram showed multiple nodular shadows and thin-walled cavity-like shadows. Cytology of sputum and bronchoalveolar lavage fluid showed class V (adenocarcinoma). Although two cycles of systemic combination chemotherapy (CDDP+VDS+MMC) were performed, his lung cancer progressed. Finally, he died of obstructive jaundice from lymph node metastasis at the pancreatic head. At autopsy, the primary site of adenocarcinoma was found to be the gallbladder. Metastatic lung tumor from gallbladder cancer is common, and thin-walled cavity-like metastasis to the lung in a young adult is a rare occurrence.

Adenocarcinoma↗