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Biomedical subjects

T Takasu

Publications and source records attributed to T Takasu.

At least 19 recordsLinked to original sources
PubMed2001

Correlations between P300 components and regional cerebral blood flows.

To evaluate the diagnostic importance of event-related potential P300, the correlation between P300 and regional cerebral blood flow (rCBF) was investigated in various brain regions in patients with multiple cerebral infarction (16 cases), chronic alcoholism (11 cases) and Alzheimer's disease (5 cases) and in seven healthy people. Cognitive function was also evaluated by mini-mental state examination. P300 latency and rCBF was measured by recording of evoked potentials using an oddball paradigm and stable xenon computed tomographic scanning, respectively. A significant (P<0.05) negative correlation between P300 and rCBF was observed in the thalamus in patients with multiple cerebral infarction and chronic alcoholism. In addition, a significant (P<0.01) negative correlation between P300 latency and the mini-mental state examination score and positive correlation between rCBF in the thalamus and the mini-mental state examination score were observed. These findings suggest that P300 latency is associated with rCBF in the thalamus and cognitive function.

Aged↗
PubMed2000

Functional role of cyclin A on induction of fibroblast apoptosis due to ligation of CD44 matrix receptor by anti-CD44 antibody.

Ligation of cell surface matrix adhesion receptors such as integrins can increase expression of specific cell cycle regulatory proteins such as cyclin A, thereby regulating cell cycle progression. Disruption of cell surface matrix receptor interaction with the extracellular matrix can trigger apoptosis. Induction of apoptosis has been linked to unscheduled up-regulation of cyclin A and activation of cyclin-A-associated dependent kinase 2 activity due to cleavage of cyclin-dependent kinase inhibitors by caspases. We have found that ligation of the cell surface matrix adhesion receptor CD44 by anti-CD44 antibody induces cell detachment and triggers apoptosis. In this report we show that ligation of CD44 by anti-CD44 antibody increases the expression of cyclin A protein prior to activation of caspase-3-like activity and morphological changes of apoptosis. Down-regulation of cyclin A protein levels by cyclin A antisense oligonucleotides dramatically decreased fibroblast apoptosis in response to anti-CD44 antibody. These data identify an important functional role of cyclin A in the induction of fibroblast apoptosis due to the ligation of the cell surface adhesion receptor CD44 by anti-CD44 antibody.

3T3 Cells↗
PubMed2000

'Iatrogenic' Wernicke's encephalopathy in Japan.

'Iatrogenic' Wernicke's encephalopathy has appeared to occur more frequently in Japan, probably induced by the change of our Japanese national health insurance policy in 1992. We report 4 nonalcoholic patients with such Wernicke's encephalopathy, which occurred during the early postoperative oral food intake period following intravenous nutrition without vitamin supplements. We analyzed the medical records of 4 patients, 3 men and 1 woman, aged between 55 and 71 years, who were admitted to our hospital between 1992 and 1995. Three patients underwent gastrointestinal surgery and 1 suffered chronic pyothorax. We diagnosed our patients as having Wernicke's encephalopathy based on typical neurological abnormalities, in addition to typical cranial magnetic resonance image findings, low serum vitamin B(1) levels, or both. Although all of the patients were treated with vitamin B(1) and showed some improvement, 1 patient developed Korsakoff syndrome, 2 made incomplete neurological recovery, and 1 died. We speculated that the body vitamin B(1) stores had been decreasing in our patients who did not receive any vitamin supplements during intravenous hyperalimentation or hydration. Subsequent administration of high calorie and high carbohydrate oral diets increased the demand for vitamin B(1), further depleting the vitamin stores, thereby causing 'iatrogenic' Wernicke's encephalopathy. The change of our national health insurance policy in 1992 discouraged the routine administration of vitamins, probably causing Wernicke's encephalopathy in our patients.

Aged↗
PubMed2000

Nationwide survey of the annual prevalence of viral and other neurological infections in Japanese inpatients.

OBJECTIVE: To estimate the annual prevalence of viral and other neurological infections at large hospitals in Japan during the period from 1989 to 1991. METHODS: A nationwide questionnaire survey on the numbers of inpatients with viral and other neurological infections was sent for completion to the chiefs of Departments of Internal Medicine, Neurology and Pediatrics at all hospitals with more than 200 beds. RESULTS: The average annual number of inpatients (and the number per 10(6) population) with encephalitis in large hospitals was estimated to be 2,200+/-400 (17.7+/-3.2), while it was 32,000+/-16,000 (258+/-129) for meningitis, and 650+/-50 (5.2+/-0.4) for myelitis. Among the inpatients with encephalitis, meningitis, and myelitis, an unknown etiology was the most common (51.2% in encephalitis, 73.2% in meningitis, and 36.3% in myelitis), followed by a viral etiology for all three diseases. CONCLUSION: The first estimate was made of the annual prevalence of viral and other neurological infections and their etiology in Japan.

Adult↗
PubMed2000

[A case of multiple cranial neuropathy with positive antinuclear antibody responded to steroid].

A 56-year-old woman was admitted to our hospital because of bilateral ptosis, total ophthalmoplegia, bilateral facial palsy and left hypoglossal nerve palsy. Antinuclear antibody (ANA) showed high titer of 1280 but other data were normal. With oral prednisolone therapy (40 mg/day), the symptoms improved gradually but ANA titer did not show any significant change. We thought multiple cranial neuropathy of the patient was due to autoimmune disease such as collagen disease or cranial nerve type of Guillain-Barré syndrome from her symptoms and positive ANA. In contrast to other reported cases of multiple cranial neuropathy with positive ANA, in our patient ANA titer was high, only motor cranial nerves were impaired, and total ophthalmoplegia was found. Steroid therapy was useful in accordance with other reports. Although our patient has no symptoms related to collagen diseases, a long follow-up of this patient is considered to be necessary.

Antibodies, Antinuclear↗
PubMed2000

Effects of bunazosin hydrochloride sustained-release formulation on cerebral circulation.

BACKGROUND: We investigated the cerebral blood flow in mild to moderately hypertensive patients with chronic cerebral infarction before and after the administration of bunazosin hydrochloride sustained-release formulation, a selective sympathetic alpha1 receptor blocker. METHODS: Eleven mild to moderately hypertensive patients (mean age 65.6 years) with chronic cerebral infarction were studied. INTERVENTIONS: The patients were on enalapril maleate, an angiotensin converting enzyme inhibitor, for one week and then enalapril maleate was switched to bunazosin hydrochloride sustained-release formulation. MEASURES: The cerebral blood flow study was performed before and 8 weeks after starting the administration of bunazosin hydrochloride sustained-release formulation. Cerebral blood flow was measured using the stable xenon CT method. The picture analysis was performed using AZ-7000. The regional cerebral blood flow was measured by placing the region of interest on the CT images. The regional cerebral blood flows were measured before and 20 minutes after intravenous injection of 17 mg/kg acetazolamide. RESULTS: The blood flows in the parietal cortex and caudate nucleus 8 weeks after starting the administration of bunazosin hydrochloride sustained-release formulation were significantly greater than those before. The cerebrovascular acetazolamide reactivity in the occipital cortex and caudate nucleus was significantly lower after switching to bunazosin hydrochloride sustained-release formulation than before. CONCLUSIONS: Considering the reports that angiotensin converting enzyme inhibitors show little influence on cerebral blood flow, the present study suggests that bunazosin hydrochloride sustained-release formulation may show a good influence on cerebral blood flow in mild to moderately hypertensive patients with chronic cerebral infarction.

Acetazolamide↗
PubMed1999

Central motor conduction time in Parkinson's disease.

Central motor conduction time (CMCT) was analysed in 11 patients with Parkinson's disease and 10 age matched healthy controls. CMCT was measured during muscle relaxation, muscle contraction and in patients with Parkinson's disease before and 1 h after intravenous infusion of L-dopa (0.25%, 20 ml). Although the CMCT during muscle contraction did not differ significantly between Parkinson's disease and healthy controls, the CMCT during muscle relaxation was significantly shorter in Parkinson's disease than in healthy controls. The CMCT during muscle relaxation in Parkinson's disease was significantly longer after intravenous infusion of L-dopa than before, but the CMCT during muscle contraction did not differ significantly before and after intravenous infusion of L-dopa. The CMCT during muscle contraction was significantly shorter than the CMCT during muscle relaxation in healthy controls. However, in Parkinson's disease, the CMCT did not differ significantly between muscle relaxation and contraction. We consider that the central motor conduction pathway during muscle relaxation in Parkinson's disease is modified to be similar to that during muscle contraction in healthy subjects. Copyright 1999 Harcourt Publishers Ltd.

Journal Article↗
PubMed1999

Regional differences in cerebrovascular reactivity to acetazolamide in Alzheimer's disease.

The cerebral blood flow and cerebrovascular reactivity to acetazolamide were investigated in Alzheimer's disease using stable xenon computed tomography (CT). Ten patients with Alzheimer's disease and 10 healthy controls were studied. The regional cerebral blood flow was measured using the xenon delivery and analysis system (AZ-7000 model, Anzai Sogyo, Tokyo, Japan) and CT (PreSage, Yokogawa Medical Systems, Tokyo, Japan). The subjects inhaled room air followed by a mixture of 30% xenon and 50% oxygen for 3 min. Serial scanning was performed once before xenon inhalation, three times in the wash-in process and five times in the washout process of 5 min. The xenon concentration in the end-tidal expired gas was recorded continuously by the thermoconductivity method. The regional cerebral blood flow was measured before and 20 min after i.v. injection of 17 mg/kg acetazolamide. The blood flows in the frontal lobe, parietal lobe and temporal lobe were reduced but the blood flows in the caudate nucleus, putamen and thalamus were normal in the Alzheimer's disease group. The cerebrovascular reactivity to acetazolamide was reduced in the frontal, parietal and temporal cortex but was normal in the other areas. There is a regional difference in the cerebral blood flow and the cerebrovascular reactivity to acetazolamide in Alzheimer's disease Copyright 1999 Harcourt Publishers Ltd.

Journal Article↗
PubMed1999

Blinded, prospective, and serial evaluation by quantitative-EEG in interferon-alpha-treated hepatitis-C.

OBJECTIVES: To estimate the effect of brain function due to IFN-alpha in chronic hepatitis C patients by the quantitative EEG. METHODS: 56 chronic hepatitis C patients were administered IFN-alpha intramuscularly at 9x10(6) IU daily for the first 4 weeks and then 3 times/week for the next 20 weeks. Serial EEGs were obtained in each subject before, at 2 and 4 weeks, and after completing the treatment. Resting EEG without artifacts was selected for quantitative EEG analysis, which was performed blindly. The frequency range was divided into delta to beta. The absolute and relative powers of each frequency band in each subject were calculated and the differences of these powers at different stages were analyzed statistically. RESULTS: The absolute powers of slow waves (delta, theta 1, and theta 2) increased while alpha 2 and fast wave (beta) decreased significantly at all locations during IFN-alpha administration. The total power and alpha 1 values revealed no significant alterations. The relative power revealed the same alteration during treatment. These changes disappeared following the treatment. Such diffuse slowing in the EEG was revealed by the total change in the whole subjects. CONCLUSIONS: Diffuse slowing in the EEG was induced by IFN-alpha, was reversible, and was evident as the total change in the subjects. These findings suggested mild IFN-alpha-induced encephalopathy.

Analysis of Variance↗
PubMed1999

Comparative study between chemiluminescence assay and two different sensitive polymerase chain reactions on the diagnosis of serial herpes simplex virus encephalitis.

OBJECTIVE: A prospective study was undertaken on the diagnosis of herpes simplex encephalitis (HSVE) by comparing chemiluminescence assay (CL) and two different sensitive polymerase chain reactions (PCRs). METHODS: The materials comprised 53 serial CSF samples from 31 patients with acute encephalitis with suspected HSVE. Each CSF was distributed to three independent laboratories to perform quantitative measurements by CL, the low sensitive (single) PCR, and high sensitive (nested) PCR. The CL provided a method of detecting HSV itself and the small fragment with HSV antigenicity which was composed of viral component proteins. The serial CSFs were found retrospectively to comprise 24 samples from 11 patients with HSVE due to HSV1 and 29 samples from 20 patients with non-HSVE. RESULTS: the CL showed 50 to 48 000 pfu/ml in all samples of HSVE (except one) taken from the 3rd to the 25th day. The low sensitive PCR demonstrated 50 to 47 000 pfu/ml in only six samples of HSVE. The high sensitive PCR disclosed less than 100 to 120 000 copies/ml in 11 samples of HSVE. At the acute stage from the 1st to 7th day, the sensitivities of CL and the high sensitive PCR were 100%, but that of the low sensitive PCR was 75%. The sensitivity of CL was significantly higher than those of both PCRs after the acute stage on the 15th to 32nd day. The specificities and positive predictive values of the three methods were 100%. However, the negative predictive value of CL was significantly higher than that of the low sensitive PCR. CONCLUSIONS: The sensitivity of CL is equivalent to that of the high sensitive PCR during the acute stage and significantly higher than that of the high sensitive PCR after the acute stage. A clear difference in sensitivity exists between the different PCRs. A combination of the PCR, chemiluminescence assay, and serological antibody diagnosis is currently considered the most effective approach for the clinical diagnosis of HSVE.

Adult↗
PubMed1999

[A case of post-infectious wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) syndrome].

The patient is a 72-year-old man who had tonsillitis and underwent incision on March 6, 1998. He complained headache and nausea from March 10 and double vision from March 12. He was admitted to our hospital on March 14. Neurological examination on March 18 revealed bilateral internuclear ophthalmoplegia with exotropia (WEBINO), bilateral ptosis and disturbance of convergence. Lumbar puncture revealed moderately elevated protein (46 mg/dl) with normal pressure and cells. The T2-weighted images of head MRI showed multiple high intensity lesions in anterior commissure and right pons. After he was treated with methylprednisolone, his headache and ptosis disappeared. The lesion in anterior commissure on MRI disappeared also. But WEBINO remained at the time of discharge. WEBINO syndrome is caused by lesion of pons and midbrain. The most common cause of bilateral internuclear ophthalmoplegia is multiple sclerosis in the European and American countries, but the frequency of vascular origin is higher in Japan than in the European and American countries. All the cases of WEBINO syndrome reported in Japan are vascular origin. This is the first case of WEBINO syndrome not of vascular origin.

Aged↗
PubMed1999

[The clinical features of cervical spondylosis with boule musculaire].

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. It was considered that the boule musculaire observed in cervical spondylosis gradually developed from a relatively mild disturbance of the ventral root. Moreover, the boule musculaire developed more often in the male patients, and predominantly on the right side. Cervical spondylosis accompanying boule musculaire may be a prodromal stage or a mild type of cervical spondylotic amyotrophy.

Aged↗
PubMed1998

Central motor conduction time and regional cerebral blood flow in patients with leuko-araiosis.

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.

Aged↗
PubMed1998

Apoptosis and perturbation of cell cycle progression in an acidic environment after hyperthermia.

The effects of an acidic environment on the induction of apoptosis by 42 degrees C hyperthermia were investigated. An acidic environment (pH 6.6) enhanced the hyperthermia-induced apoptosis in HL-60 human promyelocytic leukemia cells as judged by the DNA fragmentation, flow cytometric analysis of DNA content, and cleavage of poly(ADP-ribose) polymerase. Hyperthermia exerted no effect on the expression of Bcl-2 and Bax, regardless of the environmental acidity during heating. The time of increase in apoptosis after heating coincided with the time of decrease in the G1-phase cell population. It seemed that the increase in heat-induced apoptosis in HL-60 cells in an acidic environment was due to a direct increase in the proteolytic cleavage of poly(ADP-ribose) polymerase by acidic caspases without the involvement of Bcl-2 and Bax, and that heat-induced apoptosis occurred during G1 phase in HL-60 cells.

Apoptosis↗
PubMed1998

Effects of chemical stimulation of the rostral ventrolateral medulla on cerebral and renal microcirculation in spontaneously hypertensive rats.

We investigated whether microcirculatory responses elicited by excitation of intrinsic neurons in the rostral ventrolateral medulla (RVLM) are altered in spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto rats (WKY) were anesthetized with chloralose, 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 (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 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.

Animals↗
PubMed1998

Reactivation of herpes simplex virus type 1 in patients with Bell's palsy.

Reactivation of herpes simplex virus type 1 (HSV-1) has been implicated in the pathogenesis of idiopathic peripheral facial palsy (Bell's palsy). The present study used the polymerase chain reaction (PCR) to analyze the saliva of patients with Bell's palsy for the presence of shed HSV-1. The study involved 47 patients with Bell's palsy, 24 patients with Ramsay Hunt syndrome, and 16 healthy HSV-seropositive volunteers. HSV-1 DNA was not detected in the saliva samples from HSV-seronegative patients. The prevalence of shed HSV-1 in patients with Bell's palsy (50%) was significantly higher than that in healthy volunteers (19%, p<0.05). When saliva samples were tested within 7 days after the onset of palsy, the prevalence of shed HSV-1 in patients with Bell's palsy (40%) was significantly higher than that in patients with Ramsay Hunt syndrome (7%, p<0.05). Furthermore, HSV-1 usually became undetectable by the second week after the onset of Bell's palsy when HSV-1 was detected during the acute phase of the disease. These findings strongly suggest that reactivation of HSV-1 is involved in the pathogenesis Bell's palsy, and indicate that PCR is a useful tool for early diagnosis of HSV-1 reactivation in patients with Bell's palsy.

Antibodies, Viral↗
PubMed1998

Familial parkinsonism and dementia with ballooned neurons, argyrophilic neuronal inclusions, atypical neurofibrillary tangles, tau-negative astrocytic fibrillary tangles, and Lewy bodies.

We report four patients with a new type of familial parkinsonism and dementia consisting of an autosomal dominant inheritance, dopa-responsive parkinsonism, severe dementia, variable myoclonus and autonomic disturbances. Autopsy of two patients revealed symmetrical cerebral atrophy with fronto-temporal dominant distribution, and marked depigmentation in the substantia nigra and locus ceruleus. Neuronal loss and gliosis were observed in the deep cerebral cortex and amygdala as well as in the areas vulnerable to Parkinson's disease. In the cerebral cortex, swollen neurons with frequent granulovacuolar changes were observed, consisting of ballooned neurons and those with argyrophilic intracytoplasmic inclusions, in addition to neuropil threads. Atypical neurofibrillary tangles, which barely stained with tau antibodies, were numerous in the upper cortical layers, consisting of 15-nm straight tubules. In addition, tau-negative astrocytic fibrillary tangles were also frequent. Electron microscopically, the ballooned neurons and argyrophilic neuronal inclusions contained filamentous structures coated with fuzzy electron-dense deposits. The inclusions showed immunohistochemical features different from those of cortical Lewy bodies and Pick bodies. Occasional Lewy bodies were present in the brain stem lesions of both patients. In two of our patients, the pathology in the brain stem was similar to that of Parkinson's disease, whereas their cerebral pathology was unusual and has not been reported previously.

Adult↗