Papers by toshiaki takasu
Journal of the Autonomic Nervous System, 1998
We investigated whether microcirculatory responses elicited by excitation of intrinsic neurons in... more We investigated whether microcirculatory responses elicited by excitation of intrinsic neurons in the rostral ventrolateral medulla Ž. Ž. Ž. RVLM are altered in spontaneously hypertensive rats SHR. SHR and Wistar-Kyoto rats WKY were anesthetized with chloralose, Ž. paralyzed with tubocurarine, and artificially ventilated. Cerebral and renal blood flows CBF and RBF were simultaneously measured using laser-Doppler flowmetry. Chemical stimulation of the RVLM neurons by microinjection of L-glutamate increased arterial pressure Ž. AP and heart rate in both SHR and WKY. Stimulation of the RVLM neurons also elicited stimulus-locked increase in CBF and decrease in RBF in both groups. The % changes in CBF and RBF were dose-dependent as stimulus intensity was increased and did not differ Ž. significantly between the SHR and WKY groups. Cerebral and renal vascular resistance CVR and RVR levels were calculated from changes in CBF or RBF and those in mean AP. The percent reduction in CVR and percent elevation in RVR were dose-dependent and did not differ significantly between the two groups. The data indicate that cerebral and systemic microcirculatory responses elicited by excitation of the RVLM neurons do not differ between SHR and WKY.
日本臨床生理学会雑誌 Japanese Journal of Applied Physiology, Feb 1, 1998
Journal of the Autonomic Nervous System, 1995
We investigated the effects of neurons in the rostral and caudal ventrolateral medulla (RVL and C... more We investigated the effects of neurons in the rostral and caudal ventrolateral medulla (RVL and CVL) on cerebral and renal microcirculation in rats. Rats were anesthetized with chloralose, paralyzed with tubocurarine, and artificially ventilated. Cerebral and renal blood flows (CBF and RBF) were measured simultaneously using laser-Doppler flowmetry. Chemical stimulation of the RVL neurons by microinjection of the excitatory amino acid L-glutamate increased arterial pressure (AP), whereas that of the CVL neurons decreased AP. Stimulation of the RVL neurons also elicited a stimulus-locked increase in CBF and a decrease in RBF. The percent change in CBF and RBF was dose-dependent as stimulus intensity was increased. Cerebral and renal vascular resistance (CVR and RVR) levels were calculated from changes in CBF or RBF and changes in mean AP. The percent reduction in CVR and percent elevation in RVR were also dose-dependent. Chemical stimulation of the CVL neurons elicited a stimulus-locked decrease in CBF and an increase in RBF. The percent reduction in CBF and percent elevation in CVR were dose-dependent. The percent reduction in RVR was also dose-dependent, while the percent elevation in RBF was not significant. Blood withdrawal reduced AP by a similar degree to CVL stimulation, but did not significantly decrease CBF. The results suggest that RVL and CVL neurons integrate cerebral and systemic microcirculation.
Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, 1995
International Journal of Neuroscience, 1996
The P300 and regional cerebral blood flow were measured before and after intravenous injection of... more The P300 and regional cerebral blood flow were measured before and after intravenous injection of L-dopa in 10 patients with idiopathic Parkinson's disease and 10 patients with vascular parkinsonism. The P300 was measured with an evoked potential recorder using an oddball paradigm and the regional cerebral blood flow was measured using the stable xenon computed tomography method. The P300 latency was significantly longer and the regional cerebral blood flow in the cerebral cortex and basal ganglia was significantly lower in the Parkinson's disease group and the vascular parkinsonism group than in the age-matched healthy control group. The intravenous injection of L-dopa improved these abnormalities significantly in the Parkinson's disease group but did not improve these abnormalities in the vascular parkinsonism group. Cognitive function is considered to be impaired in Parkinson's disease and vascular parkinsonism and L-dopa is considered to improve it in Parkinson's disease.
Journal of the Autonomic Nervous System, 1990
Case reports in neurology, 2013
Crowned dens syndrome (CDS), related to microcrystalline deposition in the periodontoid process, ... more Crowned dens syndrome (CDS), related to microcrystalline deposition in the periodontoid process, is the main cause of acute or chronic cervical pain. Microcrystal-line deposition most often consists of calcium pyrophosphate dehydrate crystals and/or hydroxyapatite crystals. This report describes the case of an 89-year-old woman who presented with sudden onset, high fever, severe occipital headache, and neck stiffness. A laboratory examination revealed a markedly elevated white blood cell count (11,100/µl) and C-reactive protein level (23.8 mg/dl). These clinical findings suggested severe infection such as meningitis with sepsis. However, the results of blood culture, serum endotoxin, and procalcitonin were all negative, and cerebrospinal fluid studies revealed only a slight abnormality. The patient was first diagnosed with meningitis and treated with antiviral and antibiotic agents as well as non-steroidal anti-inflammatory drugs, but they only had limited effects. A cervical plain ...
Case reports in neurology, 2012
Thalamic lesions give rise to a variety of clinical syndromes such as pure sensory stroke, ataxic... more Thalamic lesions give rise to a variety of clinical syndromes such as pure sensory stroke, ataxic hemiparesis, and rarely involuntary movements including chorea. Generally and classically, lacunar infarction in the subthalamic nucleus has been regarded as the lesion mainly responsible for hemi-chorea and hemi-ballismus, on the basis of previous anatomical studies. This report describes the case of an 81-year-old man who developed sudden-onset pure hemi-chorea in the right limbs resulting from an acute phase of left thalamic lacunar infarction detected on a diffusion-weighted image (DWI) in an MRI study. The patient had no other neurological symptoms such as ataxic hemiparesis and sensory disturbance. A single-photon emission computed tomography (SPECT) study using the (99m)Tc-ECD Patlak plot method demonstrated significant perfusional asymmetry between the right and left thalami (p = 0.0035), consistent with the left thalamic lesion on DWI. It is speculated that this perfusional asy...
Tuberculosis research and treatment, 2012
Central nervous system (CNS) tuberculosis, particularly tuberculous meningitis (TBM), is the seve... more Central nervous system (CNS) tuberculosis, particularly tuberculous meningitis (TBM), is the severest form of Mycobacterium tuberculosis (M.Tb) infection, causing death or severe neurological defects in more than half of those affected, in spite of recent advancements in available anti-tuberculosis treatment. The definitive diagnosis of CNS tuberculosis depends upon the detection of M.Tb bacilli in the cerebrospinal fluid (CSF). At present, the diagnosis of CNS tuberculosis remains a complex issue because the most widely used conventional "gold standard" based on bacteriological detection methods, such as direct smear and culture identification, cannot rapidly detect M.Tb in CSF specimens with sufficient sensitivity in the acute phase of TBM. Recently, instead of the conventional "gold standard", the various molecular-based methods including nucleic acid amplification (NAA) assay technique, particularly polymerase chain reaction (PCR) assay, has emerged as a prom...
Rinshō shinkeigaku = Clinical neurology, 1999
To clarify the pathophysiology of boule musculaire associated with cervical spondylosis, we inves... more To clarify the pathophysiology of boule musculaire associated with cervical spondylosis, we investigated the 13 patients (11 males and 2 females) with cervical radiculopathy caused by cervical spondylosis. None of the patients had any subjective symptoms such as sensory disturbance, weakness in the boule musculaire, and muscle atrophy of the insurround region near the boule musculaire. Among 21 tendon reflexes of the biceps muscle of the arm, 9 were normal, 8 were decreased and 4 were increased. Among the 13 patients there was only 2 clinical cases of cervical myelopathy. MRI obtained from 3 patients demonstrated a compressed cervical cord. Electromyography obtained from 7 patients demonstrated mild neurogenic changes such as polyphasic or prolonged motor unit potential (MUP) in the boule musculaire and in the atrophic regions. However, there was no giant MUP, fasciculation, fibrillation, nor positive sharp waves suggesting denervating lesions below the anterior horn in any patient....
Annals of clinical and laboratory science
Amino acids were measured in nine cases of dementia of the Alzheimer type, 10 cases of multi-infa... more Amino acids were measured in nine cases of dementia of the Alzheimer type, 10 cases of multi-infarct dementia, and 10 healthy controls. The severity of dementia was examined using mini-mental state test (MMST). Amino acid analysis (41 kinds) in the cerebrospinal fluid (CSF) and serum was performed in the Special Reference Laboratories. In the dementia of the Alzheimer type group, methionine and alanine concentrations in the CSF were significantly increased, and the CSF/serum ratios for both the alanine and glycine concentrations were significantly increased, in comparison with the healthy control group. In the multi-infarct dementia group, glycine, methionine, threonine, phenylalanine, and citrulline concentrations in the CSF were all higher than in the healthy control group. Significant negative correlations were found between the MMST score and the alanine, urea, arginine, and alpha-aminobutyric acid concentrations in the CSF. The number of amino acids which exhibited abnormality ...
Functional neurology
We evaluated autonomic function in alcoholic neuropathy by non-invasive hemodynamic studies using... more We evaluated autonomic function in alcoholic neuropathy by non-invasive hemodynamic studies using servo-plethysmo-manometry and laser Doppler flowmetry. In 16 alcoholics compared with 17 age-matched healthy controls, the extent of AP responses to phase IV of the Valsalva maneuver, cold pressor test and isometric exercise decreased significantly, indicating sympathetic hypofunction. Five patients had paradoxical depressor response to cold pressor test, which was reproducible by submersion of the hand in warm water. The data suggest involvement of the higher autonomic center. Reflex bradycardia in phase IV of the Valsalva maneuver and the variation coefficient of R-R intervals in the electrocardiogram were lower, indicating parasympathetic hypofunction. Cutaneous blood flow response in the foot upon local warming and submersion of the hand in cold water was significantly impaired, but that in the contralateral hand was not. Abnormalities in the autonomic function tests may result from...
Virus Genes, 1991
The amino acid sequence of a carboxy terminal domain corresponding to the end of the outer envelo... more The amino acid sequence of a carboxy terminal domain corresponding to the end of the outer envelope projection of the hemagglutinin glycoprotein (HA) of measles and subacute sclerosing panencephalitis viruses has a high degree of homology with the active domain of long neurotoxins, which specifically binds to the nicotinic acetylcholine receptor. The homology in amino acid sequence of HA to this domain of neurotoxin, as well as native alpha-bungarotoxin (BTx), was confirmed by the following evidence: a) rabbit anti-HA monospecific sera reacted with BTx in ELISA, b) HA dose-dependently blocked the binding of radio-labeled BTx in competitive radioimmunoassay, and c) antibody to a synthetic peptide of the active domain of BTx precipitated HA in radioimmunoprecipitation. In addition, SSPE patients had significantly high titers of antibody to BTx than healthy children who had been previously infected with measles. This epitope of HA may play an important role in the transsynaptic spreading of the virus in the brain.
Rinsho Shinkeigaku, 2013
結核性髄膜炎，髄液，polymerase chain reaction(PCR) ，Nested PCR， Wide Range Quantitative Nested Real-time(WR... more 結核性髄膜炎，髄液，polymerase chain reaction(PCR) ，Nested PCR， Wide Range Quantitative Nested Real-time(WR-QNRT)PCR
Neurology, 1990
We used CT to make a quantitative evaluation of the pontine volumes of 55 patients with adult-ons... more We used CT to make a quantitative evaluation of the pontine volumes of 55 patients with adult-onset cerebellar degeneration and compared the results with their clinical records. Patients with pontine atrophy showed significantly more autonomic dysfunction and extrapyramidal signs; their other clinical features did not differ from patients without pontine atrophy. After dividing the patients into 2 groups, those with and without autonomic dysfunction or extrapyramidal signs, we found that those with these manifestations also had pontine atrophy, a later onset and shorter duration of the disease, and impairment of higher brain functions. The group without these manifestations had relatively normal pontine volume, a greater familial tendency for cerebellar degeneration, and longer duration of the disease. Our results suggest that quantitative volume evaluation of the pons by CT is important for the clinical categorization of cerebellar degeneration.
Journal of the Neurological Sciences, 1998
Central motor conduction time (CMCT) and regional cerebral blood flow were investigated in 21 pat... more Central motor conduction time (CMCT) and regional cerebral blood flow were investigated in 21 patients with leuko-araiosis. The severity of dementia was examined using mini-mental state examination. The head magnetic stimulation was performed using an SMN-1100 magnetic stimulator and a round coil with a diameter of 17 cm. The regional cerebral blood flow was measured using the stable xenon computed tomography method. The CMCT was significantly longer in the patients with dementia than in the patients without dementia. The blood flows in the parietal cortex, frontal white matter and thalamus were significantly lower in the patients with dementia than in the patients without dementia. There were significant negative correlations between the CMCT and the blood flows in the frontal cortex, temporal cortex, frontal white matter and thalamus. The significant negative correlations suggest that the prolongation of CMCT in patients with leuko-araiosis is related to the decrease in regional cerebral blood flows.
Journal of Stroke and Cerebrovascular Diseases, 1997
Ten cases of lacunar infarction, 10 cases of nonlacunar cerebral thrombosis, and 8 healthy contro... more Ten cases of lacunar infarction, 10 cases of nonlacunar cerebral thrombosis, and 8 healthy controls who did not have risk factors of cerebrovascular diseases were studied. Subcortical cystic infarctions with a diameter of less than 1.5 cm were classified as lacunar infarction and the other cerebral thrombosis were classified as nonlacunar cerebral thrombosis. Cerebral blood flow examination by Xenon computed tomography (CT) method was performed within 14 days after the onset of stroke. Stable Xenon was inhaled for 3 minutes and CT scan was taken once before the inhalation, 3 times during the inhalation, and 5 times in the washout phase. Regional blood flows in the infarcted area, around the infarcted area, and in the cerebral cortex and the cerebral white matter where the influence of the infarction was considered to be little were measured before and after intravenous injection of 17 mg/kg acetazolamide. In the lacunar infarction, the blood flow in the cerebral cortex where the influence of the infarction was considered to be little was decreased and the cerebrovascular dilatory reserve capacity in the cerebral cortex and the cerebral white matter was decreased. Arteriolosclerosis is considered to be the basic cause of lacunar infarction.
Journal of Neurology, 1997
P300 examination was performed in patients with periventricular leukoaraiosis and in patients wit... more P300 examination was performed in patients with periventricular leukoaraiosis and in patients with leukoaraiosis in the centrum semiovale. Ten patients with periventricular leukoaraiosis, ten patients with leukoaraiosis in centrum semiovale and ten age-matched controls without leukoaraiosis were studied. The P300 was measured with an evoked potential recorder using an oddball paradigm. The mini-mental state examination score was significantly lower and the P300 latency was significantly longer in the leukoaraiosis in the centrum semiovale group than in the periventricular leukoaraiosis group and the control group. Leukoaraiosis in centrum semiovale may be related to dementia and the prolongation of P300 latency.
Journal of Medical Virology, 2002
A very high annual incidence of 56 per million population below the age of 20 years for subacute ... more A very high annual incidence of 56 per million population below the age of 20 years for subacute sclerosing panencephalitis (SSPE) has been reported from Papua New Guinea (PNG). In a more recent study, we have confirmed this unusual high incidence for Eastern Highlands Province (EHP) of PNG. In the study, it was observed that the vaccination rate among SSPE patients registered at Goroka Base General Hospital (GBGH) in EHP was higher than that of other infants in the province in recent years. To identify the measles virus (MV) responsible for SSPE in EHP, sequence analysis of hypervariable region of the N gene was performed from 13 MV genomes: 2 amplified from clinical specimens of SSPE patients and 11 from acute measles patients. In 2 cases among the 11 with acute measles, nucleotide sequence of the entire H gene derived from isolated viruses was determined. Both nucleotide sequence and phylogenetic tree analyses showed that the amplified MV cDNAs were closely related to one another...
Journal of Medical Virology, 1988
The prevalence of West Nile (WN) virus infection in Karachi, Pakistan, was unknown until 1982. It... more The prevalence of West Nile (WN) virus infection in Karachi, Pakistan, was unknown until 1982. It had been noticed that there were more than a few patients with encephalitides in Karachi, and it was supposed that Japanese encephalitis (JE) cases would be found among them. Therefore, a seroepidemiological study was conducted to define the prevalence of WN virus infection and the possible occurrence of JE virus infection in the Karachi area. Prevalences of haemagglutination inhibition (HI) and neutralization (NT) antibodies against WN virus were studied among 81 serum samples (in July, 33 samples; in September, 48) during 1983, and among 156 paired serum samples that were collected twice, in July and October of 1985. Nearly the same antibody‐positive rates were obtained in July of both years (1983: HI 55%; 1985: HI 53%; NT 50%); the rates increased slightly during September/October (1983: HI 65%; 1985: HI 59%, NT 54%). Among 156 paired samples in 1985, 20 (13%) and 12 (8%) showed posi...
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Papers by toshiaki takasu