M Kojo

Oita University, Ōita, Ōita, Japan

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Publications (19)15.59 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: The central nervous system (CNS) inflammation of Kawasaki disease (KD) has not been sufficiently evaluated in spite of the complications of irritability and CSF pleocytosis. Cerebrospinal fluid (CSF) and serum inflammatory cytokine values were simultaneously examined in 10 patients (2.6 +/- 2.1 year of age) during the acute phase. They were all irritable and demonstrated mild consciousness disturbance. The CSF IL6 was elevated (>3.0 pg/mL) in 6 patients, and 4 of them showed higher CSF than serum values. The CSF sTNFR1 was elevated (>0.5 microg/mL) in 6 patients, and 1 showed higher CSF than serum values. These CSF cytokine (IL6; 81.4 +/- 192.8 pg/mL, sTNFR1; 1.1 +/- 0.8 microg/mL) and CSF/serum ratio (IL6; 2.8 +/- 5.2, sTNFR1 0.4 +/- 0.4) in patients with KD were the same as those of patients with acute encephalitis/acute encephalopathy. The differences in the inflammatory cytokine value between CSF and serum suggest that the degree of systemic vasculitis is different between CSF and the circulating blood, and some patients with KD showed a higher degree of CSF inflammation.
    The Pediatric Infectious Disease Journal 08/2007; 26(8):750-3. · 3.57 Impact Factor
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    ABSTRACT: A 7-year-old female suddenly exhibited high fever and convulsions, and entered a semi-coma. She also had thrombocytopenia, elevated aminotransferase, prolonged prothrombin time and activated partial thromboplastin time, and hemophagocytes in the bone marrow. The brain magnetic resonance imaging revealed multiple low-intensity areas on the T1-weighted images, and high-intensity areas on the T2-weighted images bilaterally in the thalamus, the dorsal part of the pons, and the cerebellar white matter. The patient was diagnosed as having both acute necrotizing encephalopathy and hemophagocytic syndrome. Serum and cerebrospinal fluid interleukin-6 and tumor necrosis factor-alpha were elevated to the same high levels (serum:cerebrospinal fluid interleukin-6, 103:101 pg/mL; tumor necrosis factor-alpha 753:753 pg/mL). The clinical symptoms and the magnetic resonance imaging findings improved immediately after the administration of dexamethasone. These results suggest that the hypercytokinemia and the hyperpermeability of both the blood-brain barrier and the capillary walls of the central nervous system might be essential in the pathogenesis of acute necrotizing encephalopathy, and that early steroid therapy might be effective in these conditions.
    Pediatric Neurology 05/2006; 34(4):315-8. · 1.42 Impact Factor
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    ABSTRACT: We report two male siblings presenting with severe hypotonia, generalized muscle atrophy, multiple joint contractures and respiratory failure. The serum creatine kinase levels were within normal limits, 75 IU/l in the younger boy and 123 IU/l in the older one. Muscle biopsies at the age of 28 days in the younger boy and 48 days in the older one revealed dystrophic pathology with increased interstitial fibrous tissue, scattered basophilic fibers and an increased number of undeveloped type-2C fibers. Although the elder brother died from respiratory failure at 4 months of age, the younger child has been sustained with mechanical ventilation, and has been exhibiting non-progressive muscle symptoms. Upon re-biopsy of the younger sibling at the age of 3 years, neither basophilic regenerating fibers nor degenerating fibers were found. All muscle fibers were found to be extremely atrophic and behaved mostly like type-1 fibers, displaying the features of congenital neuromuscular disease with uniform type-1 fibers. Since early biopsies in congenital myopathies reveal numerous undifferentiated immature muscle fibers, it is difficult to make a definite diagnosis, unless we recognize disease-specific cytoplastic abnormalities of nemaline body formation and abnormalities of core structure.
    Brain and Development 02/2006; 28(1):63-6. · 1.67 Impact Factor
  • Pediatrics International 09/2005; 47(4):459-62. · 0.88 Impact Factor
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    ABSTRACT: Abstract Background: The aim of the present study was to analyze the carotid artery blood flow waveform, using a two-dimensional autoregressive modeling approach and component analysis, and to determine the relation between cardiac contractility, peripheral and cerebral circulation and characteristic values of component activities of carotid artery blood flow waveform in patients with atrial septal defect (ASD), with or without congestive heart failure.Methods and Results: We analyzed the carotid artery blood flow waveform of nine patients with ASD and 35 normal controls using a two-dimensional autoregressive modeling approach. The component of impulse response was divided into six groups according to the damping frequency: (i) group I, 0 Hz; (ii) group II, 1–5 Hz; (iii) group III, 5_8 Hz; (iv) group IV, 8–13 Hz; (v) group V, 13–17 Hz and (vi) group VI, >17 Hz. The decrease of impulse response power-density in patients of groups I, II, III and IV and the prolongation of damping time for patients in groups I and II were particularly noticeable in two ASD patients, whose pulmonary to systemic blood flow ratio was more than 2.7 and whose left ventricular stroke volume was less than 33.1 mL/m2. The power-density of groups I and II varied with cardiac contractility and the power-density of groups III and IV varied with cerebral circulation. In contrast, the damping time of groups I and II changed with the reflection velocity from the position of arterial reflection against blood flow from left ventricle.Conclusions: These results may be influenced by the decrease in left ventricular stroke volume and velocity in arterial reflection.Key words atrial septal defect; carotid artery blood flow waveform; cerebral circulation; congestive heart failure; two-dimensional autoregressive analysis.
    Pediatrics International 02/2002; 41(3):292 - 298. · 0.88 Impact Factor
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    ABSTRACT: We investigated the effect of postural changes on cerebral circulation by measuring carotid artery blood flow (CABF) in the supine position and during head-up tilt (HUT) test using a Doppler flow meter. Subjects included 10 patients with neurally mediated syncope, 10 patients with orthostatic intolerance, 8 with epilepsy, aged between 8 to 24 years (mean +/- SD, 13.9 +/- 4.1 years). The test caused pallor and dizziness in 16 patients (symptomatic), while no symptoms were recognized in the other 12 patients (asymptomatic). Significant reductions in the mean CABF (Fm), maximum CABF (Fs) and minimum CABF (Fd), components of the CABF waveform, were noticed during HUT compared to before HUT (supine), and these reductions in symptomatic patients were more severe than those in asymptomatic patients (Fm: - 2.8 +/- 2.0 SD vs - 0.7 +/- 1.4 SD; Fs: - 2.7 +/- 1.5 SD vs - 0.9 +/- 1.3 SD; Fd: - 4.5 +/- 2.8 SD vs - 2.2 +/- 2.1 SD). Reductions in Fm, Fs and Fd in the symptomatic patients during HUT lasted longer than those of the asymptomatic patients, being statistically significant for Fm and Fs (Fm: p < 0.01; Fs: p < 0.05). The criteria during HUT for distinguishing neurally mediated syncope (NMS) from others was Fs: < - 4 SD and Fd: < - 5 SD. Our data suggest that reduction of CABF should be carefully evaluated for the diagnosis of neurally mediated syncope in pediatric patients. Such a reduction might be an essential mechanism of syncopal attacks.
    Neuropediatrics 08/2001; 32(4):169-75. · 1.19 Impact Factor
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    ABSTRACT: After diagnosing abnormality of cardiac and carotid-cerebral circulation in an infant with isolated ventricular septal defect (VSD) associated with severe congestive heart failure, the authors measured the carotid arterial blood flow volume (CABF). At 3 months, the patient was not thriving and had dyspnea because of severe congestive heart failure. The authors measured the VSD size/body surface area (BSA) ratio relative to the predicted value of the left ventricular end-diastolic dimension (%LVEDd), left-to-right shunt ratio (Qp/Qs), and the small stroke volume (SV)/BSA using echocardiography and cardiac catheterization. The mean, maximum, and minimum CABF (mean CABF, maxCABF, and minCABF) among R-R intervals on electrocardiogram were measured by Doppler flowmetry in this patient and 5 healthy age-matched control children. The patient had a large VSD size/BSA ratio (37.9 mm/m2), %LVEDd (164%), and Qp/Qs (3.8), and a small SV/BSA ratio (18 mL/m2). The mean CABF, maxCABF, and minCABF were significantly lower than those of control children (VSD patient vs. controls; 2.7 +/- 0.4 vs. 4.5 +/- 0.6, 6.1 +/- 0.9 vs. 12.0 +/- 2.1, 1.2 +/- 0.2 vs. 1.7 +/- 0.4 mL/sec (mean +/- S.D.)), respectively (p < 0.01). The authors' results showed abnormal cardiac and carotid-cerebral circulation in an infant with large VSD associated with severe congestive heart failure.
    Journal of Neuroimaging 10/2000; 10(4):241-3. · 1.41 Impact Factor
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    ABSTRACT: The aim of the present study was to analyze the carotid artery blood flow waveform, using a two-dimensional autoregressive modeling approach and component analysis, and to determine the relation between cardiac contractility, peripheral and cerebral circulation and characteristic values of component activities of carotid artery blood flow waveform in patients with atrial septal defect (ASD), with or without congestive heart failure. We analyzed the carotid artery blood flow waveform of nine patients with ASD and 35 normal controls using a two-dimensional autoregressive modeling approach. The component of impulse response was divided into six groups according to the damping frequency: (i) group I, 0 Hz; (ii) group II, 1-5 Hz; (iii) group III, 5-8 Hz; (iv) group IV, 8-13 Hz; (v) group V, 13-17 Hz and (vi) group VI, > 17 Hz. The decrease of impulse response power-density in patients of groups I, II, III and IV and the prolongation of damping time for patients in groups I and II were particularly noticeable in two ASD patients, whose pulmonary to systemic blood flow ratio was more than 2.7 and whose left ventricular stroke volume was less than 33.1 mL/m2. The power-density of groups I and II varied with cardiac contractility and the power-density of groups III and IV varied with cerebral circulation. In contrast, the damping time of groups I and II changed with the reflection velocity from the position of arterial reflection against blood flow from left ventricle. These results may be influenced by the decrease in left ventricular stroke volume and velocity in arterial reflection.
    Pediatrics International 06/1999; 41(3):292-8. · 0.88 Impact Factor
  • M Kojo, K Yamada, T Izumi
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    ABSTRACT: We examined the developmental changes in carotid arterial diameter and its change with pulsatile pressure in infants and children using the phase-locked echo-tracking method. The mean, maximum systolic, and minimum diastolic carotid arterial diameter and pulsating diameter changes were measured in 95 healthy children aged 1 month to 13 years. The mean, maximum, and minimum carotid arterial diameter increase significantly and exponentially with age, body weight, height, and body surface area, and the correlation coefficient was highest with body surface area. The change in carotid arterial diameter with pulse pressure increased gradually until 2 to 3 years of age. Our results suggest that the maturational changes in carotid diameter and the dynamic changes in the diameter reflect changes in the carotid-cerebral circulatory system. The noninvasive measurement of the carotid diameter and pulsating diameter changes by a phase-locked echo-tracking method is useful for examining carotid-cerebral circulatory disorders.
    Pediatric Neurology 04/1998; 18(3):221-6. · 1.42 Impact Factor
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    ABSTRACT: We obtained the cardio-respiratory impulse response and noise contribution ratio to study the central respiratory control system in one case of Ondine's curse, one case of sleep apnea syndrome and 34 cases of preterm infants, using multivariate autoregressive analysis. In Ondine's curse, the noise contribution ratio decreased during sleep. In the sleep apnea syndrome, the noise contribution ratio before apnea and after apnea decreased. In the preterm infants, the noise contribution ratio increased with the conceptional age. From these results, we concluded that the central cardio-respiratory control system was disturbed in Ondine's curse, sleep apnea syndrome and preterm infants. The cardio-respiratory impulse response using a multiple autoregressive analysis was useful for prediction of sudden infant death syndrome.
    No to hattatsu. Brain and development 10/1996; 28(5):379-84.
  • M Kojo, T Ogawa, K Yamada
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    ABSTRACT: We examined the developmental changes in carotid arterial blood flow in a group of neonates, infants, and children using a Doppler flowmeter. The mean, maximum and minimum carotid arterial blood flow (CABF) were measured serially in 35 healthy newborns during the first 5 days of life (total 175 records), and in 62 healthy children aged 1 month to 13 years. In newborns, the mean CABF increased significantly on the second day of life, while the maximum and minimum CABFs increased significantly every day during the first 3 days of life. The mean, maximum, and minimum CABFs increased steadily and significantly in those older than 1 month but reached a plateau after 2 to 4 years of age. Our results indicate that CABF changes with age in early life, reflecting a change in cardiac contraction and carotid-cerebral circulatory system. The measurement of CABF by Doppler flowmetry may be useful for examining cardiac and carotid-cerebral circulatory disorder.
    Pediatric Neurology 06/1996; 14(4):313-6. · 1.42 Impact Factor
  • Journal of the Autonomic Nervous System 12/1995; 56(1):135-135.
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    ABSTRACT: The carotid artery blood flow waveform (CABFW) is regarded as a summation of cardiac impulse responses. These impulse responses are divided into several components through a two-dimensional autoregressive modelling approach. Using this approach, we determined the developmental change in CABFW in 94 normal subjects from the neonatal period to adolescence. Our analysis demonstrated that: (i) the total power of impulse response increased significantly with increasing age. The component of impulse response was divided into six groups according to the damping frequency: group I (0 Hz), group II (1-5 Hz), group III (5-8 Hz), group IV (8-13 Hz), group V (13-17 Hz) and group VI (> 17 Hz); (ii) the power-density and the damping time of group I and II impulse response increased significantly with increasing age; (iii) the power-density and percent power of group III impulse response and power-density of group IV impulse response increased significantly with increasing age. Our results indicated that CABFW contained some regular impulses and that group I, II, III and IV, which were influenced by several factors, including cardiac contraction and the compliance and frictional forces of the carotid artery, appeared to be important to the developmental change of CABFW in children.
    Acta paediatrica Japonica; Overseas edition 12/1995; 37(6):677-86.
  • [show abstract] [hide abstract]
    ABSTRACT: The carotid artery blood flow waveform (CABFW) is regarded as a summation of cardiac impulse responses. These impulse responses are divided into several components through a two-dimensional autoregressive modelling approach. Using this approach, we determined the developmental change in CABFW in 94 normal subjects from the neonatal period to adolescence. Our analysis demonstrated that: (i) the total power of impulse response increased significantly with increasing age. The component of impulse response was divided into six groups according to the damping frequency: group I (0 Hz), group II (1–5 Hz), group III (5–8 Hz), group IV (8–13 Hz), group V (13–17 Hz) and group VI (> 17 Hz); (ii) the power-density and the damping time of group I and II impulse response increased significantly with increasing age; (iii) the power-density and percent power of group III impulse response and power-density of group IV impulse response increased significantly with increasing age. Our results indicated that CABFW contained some regular impulses and that group I, II, III and IV, which were influenced by several factors, including cardiac contraction and the compliance and frictional forces of the carotid artery, appeared to be important to the developmental change of CABFW in children.
    Pediatrics International 11/1995; 37(6):677 - 686. · 0.88 Impact Factor
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    ABSTRACT: We analyzed the carotid artery blood flow waveform (CABFW) of an infant of a non-insulin dependent diabetic mother with hypertrophic cardiomyopathy (IDM cardiomyopathy) through multivariate autoregressive analysis and compared the developmental change of his CABFW with that of normal newborns. The total power was lower than normal newborns on the second and third day of life when his heart dysfunction was severe, and elevated on the fifth day of life when normal-heart function was recovered. The power of component 3 (C3), of which the damping frequency was 7-11 Hz, was slightly high on the second and third day of life and it decreased to the normal range on the fifth day of life by component analysis. In contrast, the power of C3 increased with decreasing resistance index of anterior cerebral artery (RI of ACA) which shows the cerebral vascular resistance of normal newborns. These results suggest that the carotid artery blood flow volume decreased by low cardiac output and the cerebral vascular resistance decreased to maintain the cerebral circulation, when the heart dysfunction was severe.
    Acta paediatrica Japonica; Overseas edition 11/1995; 37(5):588-93.
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    ABSTRACT: We analyzed the carotid artery blood flow waveform (CABFW) through multivariate autoregressive analysis in a case with multicystic encephalomalacia (MCE) after neonatal asphyxia and compared the result with those of 35 healthy newborns. The total power of CABFW was at the -2 SD level of the value for 35 healthy newborns, and the power, % power, bio-informing amounts and damping time of component 3 (damping frequency 11.15 Hz) were less than -2 SD of the values in 35 healthy newborns. The Pulsatility Index (PI) of anterior cerebral artery (ACA) was high (0.76). These results suggest that cerebral blood flow decreases because of cerebral vasoconstriction in MCE after neonatal asphyxia.
    No to hattatsu. Brain and development 06/1995; 27(3):184-90.
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    ABSTRACT: We applied spectral analysis through multivariant autoregressive model fitting [1] to RR interval (RRI) and respiratory (RES) oscillation obtained during quiet sleep in an infant with congenital central hypoventilation syndrome (Ondine's curse), a child with obstructive sleep apnea, and two healthy children. Power spectra, impulse response and noise contribution ratio between RRI and RES oscillation were calculated by using a minicomputer PFU-1200 (FACOM) to determine the structure of the feedback system between RRI and RES within the central nervous system. We found that the respiratory noise contribution ratio to RRI was significantly smaller in Ondine's curse (37 +/- 7.7%, at 0.23 Hz) than in obstructive sleep apnea (90 +/- 6.7%, at 0.39 Hz) and healthy subjects. We postulate that the result shows disturbance of the central autonomic control of breathing and heart rate in Ondine's curse.
    Journal of the Autonomic Nervous System 02/1993; 42(1):41-52.
  • Journal of The Autonomic Nervous System - J AUTONOM NERV SYST. 01/1993; 42(1):41-51.
  • Journal of The Autonomic Nervous System - J AUTONOM NERV SYST. 01/1992; 41(3):233-233.

Publication Stats

47 Citations
15.59 Total Impact Points

Institutions

  • 1995–2007
    • Oita University
      • • Department of Brain and Nerve Science
      • • Department of Pediatrics
      Ōita, Ōita, Japan

Disciplines