Biomedical subjects

H Tohgi

Publications and source records attributed to H Tohgi.

At least 73 records · Page 4Linked to original sources

PubMed1995

Reduced and oxidized forms of glutathione and alpha-tocopherol in the cerebrospinal fluid of parkinsonian patients: comparison between before and after L-dopa treatment.

In the cerebrospinal fluid of untreated patients with Parkinson's disease (PD) the concentrations of reduced glutathione (GSH) and alpha-tocopherol (alpha-TOH) were unaltered but the concentration of oxidized glutathione (glutathione disulfide, GSSG) (P < 0.001), the GSSG/GSH ratio (P < 0.06), alpha-tocopherol quinone (alpha-TQ) (P < 0.001), and the alpha-TQ/alpha-TOH ratio (P < 0.01) were reduced significantly. In L-dopa-treated patients, the concentrations of GSH, GSSG, and the alpha-TQ concentration and the alpha-TQ/alpha-TOH ratio (P < 0.05) increased compared with untreated PD patients. These results suggest that oxidation of GSH and alpha-TOH is decreased in untreated PD patients, but is activated to a control level or more after L-dopa treatment.

Aged↗

PubMed1995

Effects of citalopram, a synthetic serotonin uptake inhibitor, on indoleamine and catecholamine concentrations in the cerebrospinal fluid of freely moving rats.

We studied changes in the concentrations of 5-hydroxytryptamine (5-HT), other indoleamines, and catecholamines in the cerebrospinal fluid (CSF) of freely-moving rats that had been administered citalopram, +/-1-[3- (Dimethylamino)propyl)-1-(4-fluorophenyl)-1, 3-dihydro-5-isobenzo-furancarbonitrile hydrobromide), a selective inhibitor of 5-HT uptake. In a microdialysis experiment, the intracerebral extracellular free 5-HT increased significantly, peaking 60 to 90 min after citalopram (30 mg/kg p.o.) was administered. The 5-HT concentrations in CSF from the cisterna magna increased significantly, reaching a maximum 6 hours after a single dose of citalopram (30 mg/kg p.o.) was given. Six hours after this dose, the CSF 5-HT concentration in the cisterna magna was significantly increased, and the 5-hydroxyindoleacetic acid (5-HIAA) concentration was significantly decreased. There were non-significant changes in the other indoleamines (tryptophan, 5-hydroxytryptophan, and kynurenine) and in the catecholamines (dopamine, homovanillic acid, normetanephrine, and 3-methoxy-4-hydroxyphenethyleneglycol). The 5-HT/tryptophan ratio was correlated significantly with the kynurenine/tryptophan ratio before treatment with citalopram (r = 0.81, p = 0.051), indicative that there is coordination of the serotonin and kynurenine pathways in normal rats. In the animals posttreatment there was no such correlation, suggesting that the changes in 5-HT are independent of the kynurenine system at least within the 6 hours postreatment. These CSF results appear to reflect selective inhibition of 5-HT uptake in brain tissues by citalopram that is not associated with changes in catecholamines.

Animals↗

PubMed1995

Indoleamine concentrations in cerebrospinal fluid from patients with Alzheimer type and Binswanger type dementias before and after administration of citalopram, a synthetic serotonin uptake inhibitor.

We studied changes in the concentrations of serotonin (5-HT), kynurenine, and other indoleamines in the cerebrospinal fluid of patients with Alzheimer type dementia (ATD) and those with Binswanger type vascular dementia (VDBT), and changes in these indoleamine concentrations 2 weeks after administration of citalopram, a 5-HT uptake inhibitor. The concentrations of total 5-HT (p < 0.005) and kynurenine (p < 0.005) were significantly decreased in ATD patients in comparison to those of the controls. After citalopram administration, there was a remarkable increase in 5-HT concentration (249%, p < 0.0001) and a significant decrease in 5-HIAA concentration (22%, p < 0.02). In the VDBT patients, only 5-HT showed a significant decrease (p < 0.005) in comparison to the control values. It also increased significantly (214%) after citalopram administration. The 5-HT/tryptophan and kynurenine/tryptophan ratios were not correlated for the controls, but did significantly for the ATD and VDBT patients; after citalopram treatment, the increase in 5-HT/tryptophan was correlated significantly with that of kynurenine/tryptophan for ATD, but not for VDBT. These results suggest that both the serotonin and kynurenine pathways are impaired in ATD; whereas, the serotonin pathway alone is in VDBT, and that these impairments are ameliorated by the administration of citalopram.

Aged↗

PubMed1995

Agraphia and acalculia after a left prefrontal (F1, F2) infarction.

A patient presented with agraphia and acalculia associated with a left frontal (F1, F2) infarction. He made mainly phonological but also lexical errors in writing (syllabograms), but his ability to write kanji (morphograms) was relatively preserved. Although he could add and subtract numbers, he could neither multiply nor divide them because of a difficulty in retrieving the multiplication tables and calculation procedures. Positron emission tomography showed decreased cerebral blood flow and metabolism limited to the infarct site. These findings suggest that agraphia and acalculia may occur associated with a left prefrontal lesion, and that the retrieval of arithmetic processes is modality specific.

Agraphia↗

PubMed1995

A randomized trial of E5510 versus aspirin in patients with transient ischemic attacks. The Japanese E5510 TIA study-1 (JETS-1) Group.

In a randomized double-blind trial, the Study Group compared the efficacy of E5510, a novel antiplatelet agent, and aspirin in preventing the recurrence of transient ischemic attacks (TIA). In total, 227 patients who suffered from TIA in the twelve weeks prior to the study were enrolled. They were randomly allocated to three treatment groups, ie, 71 patients in the E5510 4 mg group, 77 patients in the E5510 2 mg group, and 79 patients in the aspirin 324 mg group, and were treated for twelve to twenty-four weeks. The incidence of recurrent TIA or stroke was 21.5% in the aspirin group and was significantly lower in the E5510 groups, being 8.5% in the 4 mg group (P < 0.05) and 11.7% in the 2 mg group (P < 0.05). Adverse events were observed in 5 cases in the 4 mg group, in 8 cases in the 2 mg group, and in 10 cases in the aspirin group, but none of them were serious. Since safety was judged to be comparable among the three groups, E5510 appears to be an antiplatelet agent for the treatment of TIA with a clinical benefit over aspirin.

Aged↗

PubMed1995

[Fas antigen gene in thymuses from patients with myasthenia gravis].

The Fas antigen is a cell surface protein that can mediate apoptosis, and plays a major role in functional maturity in clonal deletion of autoreactive T cells in the thymus. Recently a cDNA encoding the human Fas antigen was isolated. It was suggested that a signal-transducing domain, along with inhibitory one, was presented in the cytoplasmic domain of the Fas antigen. We examined whether any abnormality in Fas antigen gene may breakdown the immunotolerance in patients with myasthenia gravis (MG). We used single-strand conformational polymorphism (SSCP) analysis, generally used to screen for unknown mutation, to examine the cytoplasmic cDNA of Fas antigen obtained by reverse transcription (rt)-PCR from mRNA of MG thymuses. Furthermore, we studied in situ expression of Fas antigen mRNA in thymuses from MG patients. Fragments from all the 12 (3 control subjects, and 9 MG patients) thymuses produced by rt-PCR showed equally stained two bands of the two single strands. In the thymuses from both controls and MG patients, the Fas antigen mRNA was mainly expressed in small thymic cells. These cells were located near clustered cells with relatively large cytoplasms in the cortex and sometimes surrounded them, but were also founded in clusters in the follicules. In situ expressions of Fas antigen mRNA were more remarkable in MG thymuses than in control subjects, and in hyperplastic thymuses than in normoplastic ones. These results suggest that mRNA for the cytoplasmic domain of the Fas antigen have no mutation, and its expression is not reduced in thymuses from patients with MG.

Adolescent↗

PubMed1995

[Dysarthria due to small cerebral infarction--the localization of lesion and clinical characteristics].

We compared locations of infarctions and clinical characteristics for patients with dysarthria and those without dysarthria. Subjects were 40 patients with a small infarction in the corona radiata or junctional zone to the capsule and 13 patients with infarctions in the internal capsule. Left corona radiata/junctional zone infarctions were significantly smaller than right sided lesions. Dysarthria was associated more frequently with the corona/junctional lesions on the left side than the right sided lesions. Asymptomatic infarctions on the contralateral side were seen in 41% of the patients with dysarthria. In these cases, dysarthria continued longer and dysphagia occurred more frequently than the cases without right sided lesions. Corona radiata/junctional zone infarctions with dysarthria were located significantly more anteriorly than those without dysarthria. The corona radiata/junctional zone infarctions presenting with dysarthria alone, upper limb dominant hemiparesis, and lower dominant hemiparesis were located in the anterior, middle, and posterior areas, respectively. In conclusion, dysarthria may occur with unilateral small cerebral infarctions, more frequently with left sided lesions than with right sided lesions. It is assumed that the left corona radiata/junctional zone infarction may interrupt simultaneously the corticobulbar pathway and callosal fibers to the right hemisphere which transmit motor information for speech to the right hemisphere. It is also possible that there are individual variations in the proportion of crossed and uncrossed corticobulbar innervation, which may explain dysarthria with unilateral cerebral lesions in some patients. It was suggested that there is an anterior-posterior somatotopy in the corona radiata/junctional zone as well as in the internal capsule.

Cerebral Infarction↗

PubMed1995

[Vimentin and desmin expression in the type 2 fibers in muscle biopsies from myotonic dystrophy patients].

Immunoreactivity for the intermediate filament proteins vimentin and desmin was assessed in the type 2 fibers of biceps brachii muscle biopsies from 20 adults with myotonic dystrophy (MD). Some type 2C fibers showed strong reactivity with both anti-vimentin and anti-desmin, suggesting that they were regenerating fibers. Some type 2A and 2B fibers of various diameter were weakly reactive with anti-vimentin, but none of the type 1 fibers were reactive with anti-vimentin. Hardly any reactivity with anti-vimentin was demonstrated in patients in the younger age group (10-29 years) with mild illness, but vimentin-positive type 2 fibers increased in the age groups 30 years of age and older. The mean diameters of type 2A and type 2B fibers in vimentin-positive patients were larger than in vimentin-negative patients. In the patients in the 30 years of age and older group, the vimentin-negative patients had more severe muscle weakness than the vimentin-positive patients. These findings suggest a possible relationship between the process of regeneration in type 2 fibers in adult MD patients and the increase in their mean diameter.

Adolescent↗

PubMed1995

[A case of spontaneous cervical carotid artery dissection].

We report a patient with spontaneous cervical internal carotid artery (ICA) dissection. A 46-year-old woman had experienced left neck pain for 10 days. One month later, she was admitted because of the sudden onset of right hemiparesis and left amaurosis, which lasted for 30 minutes. On hospital day 3, the patient experienced the sudden onset of right hemiparesis and total aphasia, which lasted for two weeks. A CT scan failed to reveal any abnormal findings. Cerebral angiograms showed irregular narrowing of the left internal carotid artery distal to the carotid sinus and extending to the base of the skull ("string sign"). Magnetic resonance imaging (MRI) revealed a high signal intensity crescent-shaped mass expanding the wall of the left ICA and narrowing its lumen. SPECT scans showed decreased cerebral blood flow in the left hemisphere. When the symptoms progressed despite-conservative therapy, surgery was performed (STA-MCA anastomosis). Many patients who develop spontaneous ICA dissection show recovery to normal arterial caliber angiographically 1 to 3 months after the onset. Thus, careful monitoring of the clinical course is important and in cases of impending stroke, surgery should be performed immediately.

Aortic Dissection↗

PubMed1995

A desk top computer program for visualized statistical analysis of lesional images in intracerebral hemorrhage.

Statistically identified information on the relationships between the sites of lesions in intracerebral hemorrhage (ICH), risk factors such as a smoking or drinking habit, anamnesis, and biochemical data through blood tests will extend assistance to neuromedical clinicians on their daily clinical duties. It will provide them with a useful guide to determine the method of treatment. Also, it will be a basic research material for their clinical studies on diagnosis, progress, or prognosis in ICH. In order to obtain such statistics with the help of the computer, we need to have a computationally effective image database system. As is generally known, medical image data especially requires a great amount of storage; high-speed processing techniques are therefore also needed to deal with such data effectively. In addition, it is desired that we have outputs from the analysis edited with well-visualized effect, using 3D computer graphics, etc. These are why most existing image processing systems have been designed to work on comparatively large-scale computers. So far as we know, it is hard to find a practical and inexpensive personal computer-based application system for visualized statistical analysis of lesional images in ICH. We have developed a desk top computer-based program for statistical analysis of lesional image data of ICH. With this system, we can organize a medical image database that consists of the personal data of patients with ICH (sex, age, occupation, diagnosis, symptoms, part of physical disorder, etc.), risk factors, anamnesis (cerebral apoplexy, hypertension, hypotension, corpulence, diabetes, hyperlipidemia, atrial fibrillation, valvular endocarditis, etc.), biochemical data of blood, and lesional image data from CT or MRI. This system consists of the following components: 1) database management, 2) information retrieval (IR), 3) lesional image processing, 4) statistical analysis, and 5) prognostic prediction. The images are drawn manually on prescribed data sheets by tracing CT or MRI films and are read through the image scanner; then the compressed data of the digitized images is recorded in the database. Each recorded image data consists of the following two components: the frame image that corresponds to the contour of tissues of interest on the corresponding sliced section, and the actual image that corresponds to the lesion itself. In our system, these two images are separately stored and managed so that we can effectively perform subsequent image analysis. Other variables in the database (risk factors, anamnesis, etc.) are mainly used as search keys for making the aggregate of image data by the IR subsystem. In any aggregate, its elements, namely image data, have common medical background descriptions with the search keys. These aggregates can be used as input for the lesional image processing subsystem. With this subsystem, we can obtain the accumulated distribution of frequencies within a specified range of any sliced section, display planar color maps and profiles associated with the distribution, reconstruct it in 3D form, perform transformations of 3D images (zooming, enhancement, rotation, etc.), and test the significant difference of frequencies between any two different sites. We have been making practical use of this system to find the neurological relationship between the symptom (dysarthria, and paralysis of upper/lower limbs) and the site of lesion with cerebral infarction in pons. This study is quite important since the distributions of pyramidal tract related to the above symptom in pons are not well-known compared to those in cerebral cortex, internal capsule, or cerebral peduncle. With our system, we have obtained several findings expected to be helpful for this study. However, since this study is still in the initial phases, we will only present the outcome as a working example of our system. Our system was originally developed for analyzing lesional images with ICH. However, it could

Cerebral Hemorrhage↗

PubMed1995

[Two cases of superficial siderosis of the central nervous system. Findings of the cerebrospinal fluid, magnetic resonance imaging and positron emission tomography].

Two cases (case 1, a 45-year-old man; case 2, a 68-year-old man) of superficial siderosis of the central nervous system are presented. Main neurological symptoms were anosmia, sensorineural deafness, dysarthria, ataxia, and pyramidal tract signs. Lumbar puncture revealed bloody cerebrospinal fluid (CSF) in both cases. In case 1, the CSF became watery clear after administration of hemostatic medicines. T2-weighted magnetic resonance images showed cerebellar atrophy and marginal hypointensity of the brainstem, cerebellum, and the entire spinal cord. T2-weighted images of the cranial nerves showed hypointensity of the VIII nerves which were clinically impaired as compared with normointensity of the VII nerves which presented no clinical symptom. These findings may reflect difference in the degree of hemosiderin depostion between the VII and VIII nerves. While case 1 had a borderline score of WAIS-R (IQ79), case 2 showed overt dementia (performance IQ65). Positron emission tomography showed that cerebral blood flow and cerebral oxygen metabolism were reduced in the basal temporal lobes in both cases.

Aged↗

PubMed1994

Remarkable reduction in acetylcholine concentration in the cerebrospinal fluid from patients with Alzheimer type dementia.

We determined the concentrations of acetylcholine (ACh) and choline (Ch) in the cerebrospinal fluid (CSF) of patients with Alzheimer type dementia (ATD) in comparison with controls. The ACh concentration was reduced significantly and remarkably (73%, P < 0.0002) in ATD patients and had a significant positive correlation with dementia scale scores (r = 0.82, P < 0.05). The Ch concentration was unaltered in ATD patients. These results suggest that the progressive reduction in ACh in the ATD brain may be reflected in its concentrations in the CSF.

Acetylcholine↗

PubMed1994

Concentrations of alpha-tocopherol and its quinone derivative in cerebrospinal fluid from patients with vascular dementia of the Binswanger type and Alzheimer type dementia.

We determined the concentrations of alpha-tocopherol (alpha-TOH) and alpha-tocopherol quinone(alpha-TQ), an oxidized derivative of alpha-TOH, in cerebrospinal fluid from patients with Alzheimer type dementia (ATD) and those with vascular dementia of the Binswanger type (VDBT). Compared with results for the controls, the VDBT patients had unaltered concentrations of alpha-TOH, but a statistically significant, 3.6-fold increase of alpha-TQ (P < 0.01) which was significantly correlated with decreases in the Mini-Mental State Examination scores (P < 0.05). In contrast, ATD patients had significantly decreased concentrations of alpha-TOH (P < 0.01), but had unaltered concentrations of alpha-TQ. These results suggest that there is greater oxidation of alpha-TOH to alpha-TQ in VDBT brain, but are inconclusive about the occurrence of peroxidation in ATD brains.

Aged↗

PubMed1994

Muscle histopathology in myotonic dystrophy in relation to age and muscular weakness.

We studied histopathological changes in the biceps brachii muscle in relation to age and the degree of muscle weakness in 64 patients (aged 11-59 years) with myotonic dystrophy. The proportion of type 1 fibers was unaltered in the adolescent patients compared with control values, but increased with age. The average diameters of all the fiber types were smaller than control values in the adolescents, suggesting immature development; however, there was an increase in diameter with age that was associated with an increase of hypertrophic type 2 fibers. At all ages, type 1 fibers were smaller than type 2 ones. Small angular fibers and small group atrophy consisted mainly of type 1 fibers, their incidences decreasing with age. The severity of muscular weakness was related to the predominance of type 1 fibers, the reduction in the number of hypertrophic type 2 fibers, and the accumulation of adipose cells, but not to the presence of small angular fibers or to small group atrophy.

Adult↗

PubMed1994

Prosopagnosia without topographagnosia and object agnosia associated with a lesion confined to the right occipitotemporal region.

A patient is presented who developed prosopagnosia with a recent occipitotemporal infarct in the distribution of the right posterior cerebral artery. He did not have topographical agnosia or object agnosia. He regained the ability to recognize faces of familiar persons, whereas he remained unable to identify faces of persons whom he met after the disease onset. This case demonstrates that prosopagnosia may occur as a deficit of matching a perceived face to a memory store of the face, and that the failure to recognize unfamiliar faces may be due to the inability to form memory stores of new faces. These deficits can occur in association with a lesion confined to the right occipitotemporal region.

Agnosia↗

PubMed1994

The anticardiolipin antibody in elderly stroke patients: its effects on stroke types, recurrence, and the coagulation-fibrinolysis system.

Anticardiolipin antibody (aCL) is known as a risk marker for stroke, particularly in subjects younger than 50 years of age. We studied the effects of aCL on stroke types, recurrences, and the coagulation-fibrinolysis system in 257 elderly patients (63.2 +/- 11.4 years). Follow-up was performed for 3.1 years on 184 patients, for whom the rate of symptomatic and asymptomatic reinfarcts on CT was studied. aCL was positive in 30 (12%) of the patients. The incidence of atherosclerotic changes in the cerebral arteries was not significantly different between aCL-positive and aCL-negative patients. The aCL-positive patients had a greater rate of individuals not having any of the known risk factors (p < 0.05), a greater incidence of cortical infarctions (p < 0.05), more frequent symptomatic recurrences (p < 0.05). They had significantly greater changes in molecular markers for the coagulation-fibrinolysis system in the acute phase (p < 0.05), but not in the chronic phase.

Aged↗

PubMed1994

Comparison of symptomatic and asymptomatic reinfarctions after small subcortical stroke.

We compared possible factors leading to symptomatic and asymptomatic reinfarcts in 207 patients an average of 2.1 years after their index atherothrombotic stroke presenting with small subcortical infarcts. Symptomatic reinfarcts were mostly small infarcts in the perforating artery regions associated with angiographic evidence of atherosclerosis of parent arteries (large-artery disease), a high hematocrit, elevated fibrinogen and Lp(a) levels. They occurred with insufficient inhibition of platelet aggregability in patients receiving antiplatelet medication. In contrast, many asymptomatic reinfarcts were small perforator infarcts not associated with large-artery disease or cortical infarcts, and occurred in the absence of hematologic risk markers, and in spite of sufficient inhibition of platelet aggregability.

Aged↗

PubMed1994

Effect of plasma fibrinogen concentration on the inhibition of platelet aggregation after ticlopidine compared with aspirin.

BACKGROUND AND PURPOSE: Elevated levels of plasma fibrinogen are a risk factor for cerebral infarction. Because fibrinogen plays a central role in platelet aggregation and binding of fibrinogen to platelets is inhibited by ticlopidine, we studied the effect of the plasma fibrinogen concentration on the antiaggregatory action of ticlopidine compared with that of aspirin. METHODS: We determined platelet aggregability before and after administration of ticlopidine (200 mg/d) or aspirin (81 mg/d) in 61 stroke patients and correlated the changes with the plasma fibrinogen concentration. RESULTS: In patients receiving ticlopidine, the platelet aggregability induced by 1, 5, and 10 mumol/L adenosine diphosphate significantly decreased compared with aggregability before medication (P < .05), and the reductions had significant negative correlations with the plasma fibrinogen concentration (P < .05). In patients receiving aspirin, the platelet aggregability induced by 2 micrograms/mL collagen and 5 and 10 mumol/L adenosine diphosphate decreased compared with aggregability before medication (P < .005), but the reductions had no significant correlation with the plasma fibrinogen concentration. CONCLUSIONS: The relative antiaggregatory effect of ticlopidine is significantly decreased with higher plasma fibrinogen concentrations. This may explain, at least in part, the individual variation in the response to ticlopidine.

Adenosine Diphosphate↗