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Biomedical subjects

Y Mizuno

Publications and source records attributed to Y Mizuno.

At least 361 records · Page 20Linked to original sources

Clinical trial of piracetam in patients with myoclonus: nationwide multiinstitution study in Japan. The Myoclonus/Piracetam Study Group.

Sixty patients with disabling myoclonus excluding mainly spinal myoclonus were treated by piracetam as an open-labeled study, and myoclonus score, neurological symptoms, functional disability, and intensity of myoclonus were scored before and after treatment, including a blinded video inspection. Electrophysiological correlation also was investigated before and after treatment. Piracetam was effective in myoclonus, especially that of cortical origin, in both monotherapy and polytherapy. Piracetam also had positive benefits on gait ataxia and convulsions but not on dysarthria, and feeding and hand writing improved much more significantly. Psychologically significant improvement was seen in decreased motivation, sleep disturbance, attention deficit, and depression, all of which might be possibly secondary benefits associated with improvement of myoclonus. There was no positive correlation between clinical and electrophysiological improvement. Tolerance was good, and side effects were transient. However, hematological abnormalities observed in at least two patients in the present study should be kept in mind when relatively large doses of piracetam are administered, especially in combination with other antimyoclonic drugs.

Administration, Oral↗

Genetic association between cytochrome P450IA1 gene and susceptibility to Parkinson's disease.

Idiopathic Parkinson's disease (PD) is a multifactorial neuro-degenerative disorder resulting from environmental factors acting on genetically susceptible individuals with normal aging. Cytochrome P450IA1 is a dioxin-inducible enzyme which is responsible for the activation of procarcinogens and environmental pollutants, such as benzo[alpha]pyrene and other aromatic hydrocarbons. The frequencies of polymorphic alleles of cytochrome P450IA1 gene (CYPIA1) were studied in 126 unrelated patients with PD in comparison with 176 healthy Japanese. The frequency of the Msp I polymorphic allele, a variant of CYPIA1 (m2), was significantly higher in patients with PD (0.444) than in controls (0.349). The risk of PD in homozygotes for m2 was 2.34-fold greater than homozygotes for the wild-type, m1. The relative risk for PD in homozygotes for CYPIA1Val was 6.54-fold higher than in homozygotes for the wild type (CYPIA1Ile)(p < 0.001). These results strongly suggest that the CYPIA1 might be one of the susceptibility genes for PD.

Adult↗

Assignment of the gene encoding type 1 gamma protein phosphatase catalytic subunit (PPP1CC) on human, rat, and mouse chromosomes.

Using fluorescent in situ hybridization (FISH) method, a gene encoding the catalytic subunit of protein phosphatase type 1 gamma (PPP1CC) was mapped to human 12q24.1-q24.2, rat 7 q22, and mouse 10C. These results indicate that the PPP1CC is a member of conserved synteny group between rat chromosome 7, mouse chromosome 10 and human chromosome 12. These data and mapping data about other members of PP1 family show that in spite of the high identity of PP1 isoforms, each isoform is encoded by different genes which located on different chromosomes in human, rat, and mouse.

Animals↗

Histochemical detection of apoptosis in Parkinson's disease.

Apoptosis may be an important mechanism of cell death in some experimental disease models as well as in human neurodegenerative disorders. We report evidence to indicate apoptosis in the substantia nigra of Parkinson's disease patients. We studied the midbrains of 7 patients with late onset PD, 4 patients with young onset PD and 6 control subjects using the nick-end labeling method. Intense nuclear staining indicating apoptotic process was observed in 8 out of 11 parkinsonian patients studied. Apoptosis may be a contributor to the nigral neuronal death in Parkinson's disease (PD).

Age of Onset↗

Attenuation of cardiotoxicity of daunomycin using a complex with heparin.

Daunomycin (DM) is one of the most important antitumor agents. However, the cardiotoxicity of DM limits it's clinical use. We have made an ionic complex with heparin to decrease the cardiotoxicity. Cardiotoxicities of DM and DM-heparin complex were compared in hamsters. On the electrocardiogram (ECG), two of the four hamsters given DM showed the serious abnormality, bidirectional ventricular premature contraction, while the hamsters given DM-heparin or saline had no abnormalities. On pathological examination, cardiac tissue in hamsters given DM showed deposition of basophilic materials, mild eosinophilic change of myofibrils and microvascuolization, whereas no change was observed in hamsters given DM-heparin complex or saline. Acute toxic effects on survival rates and body weights were more profound in DM-infused mice than in DM-heparin-infused mice. DM and DM-heparin complex showed similar anticancer activity both in vivo and in vitro. Thus, the present study suggests that the DM-heparin complex may attenuate the cardiotoxicity of DM without affecting it's antitumor effect in humans.

Animals↗

Effect of dopamine, dimethoxyphenylethylamine, papaverine, and related compounds on mitochondrial respiration and complex I activity.

We report the effect of papaverine, tetrahydro-papaverine, laudanosine, dimethoxyphenylethylamine, dopamine, and its metabolites on mitochondrial respiration and activities of the enzymes in the electron transfer complexes, as mitochondrial toxins may be implicated in the etiology and the pathogenesis of Parkinson's disease. Papaverine was the most potent inhibitor of complex I and NADH-linked mitochondrial respiration among the compounds tested next to rotenone. Tetrahydropapaverine, dimethoxyphenylethylamine, and laudanosine also inhibited NADH-linked mitochondrial respiration and complex I activity in this order. Dopamine and its metabolites showed either no inhibition or only very week inhibition. Compounds with dimethoxy residues in the phenyl ring were associated with more potent inhibition of complex I than those without. Our results warrant further studies on these and some related compounds as candidate neurotoxins causing Parkinson's disease.

Animals↗

Expression of glucose transporters in rat brain following transient focal ischemic injury.

We have investigated the serial changes in the transcription and translation of the rat glucose transporter (GLUT) 1 and 3 genes after 3 h of middle cerebral artery (MCA) occlusion followed by reperfusion. Northern blot analysis and in situ hybridization study were performed to determine the chronological change and regional expression. In the ipsilateral anterior cerebral artery (ACA) cortex, GLUT1 mRNA expression was increased at 12 h (11.6-fold) of reperfusion, and its expression was detected not only in vascular endothelial cells but also in neurons. At 48 h of reperfusion, GLUT3 mRNA expression was increased in the ipsilateral ACA (8.6-fold) and in the contralateral MCA cortex (9.1-fold). Immunohistochemical study failed to show GLUT1 protein synthesis in neurons in the ipsilateral ACA cortex. The immunoreactivity of GLUT3 protein was increased in neurons in ipsilateral ACA cortex and contralateral MCA cortex. Our results suggest that the expression of GLUT1 and GLUT3 is controlled differently after transient focal ischemic conditions. Furthermore, the postischemic localizations of both GLUT1 and GLUT3 expressions may be altered from the normal physiological expression pattern, which may be of importance in investigating postischemic cell function.

Animals↗

Neurosensory hearing loss in secondary adhalinopathy.

We report mild-to-moderate neurosensory hearing loss and severe childhood autosomal recessive muscular dystrophy with adhalin-deficiency in two siblings from a Bulgarian sibship of Turkish origin. Microsatellite analysis excluded linkage to the adhalin gene, mutations of which cause limb girdle muscular dystrophy (LGMD) 2D, but was compatible with linkage to the gene locus of LGMD 2C on chromosome 13q12. Compound heterozygosity of the affected siblings was detected in this chromosomal region. A severe autosomal recessive form of neurosensory deafness has been linked to the same region (locus NSRD1) which is now contained in a 7 Mb YAC contig. Using polymorphic markers and STS PCR primers mapping in this contig, we did not find evidence for major rearrangements in the suspected region. These preliminary findings are not in favor of, but do not completely exclude a contiguous gene syndrome in these cases. Therefore, we consider a potential role of the putative 13q12 gene product and/or adhalin in neurosensory hearing.

Alleles↗

Alterations in activity of protein tyrosine phosphatase SH-PTP1 in autoimmune MRL/mpj-lpr/lpr mice.

Activities of protein tyrosine kinase (PTK) and protein tyrosine phosphatase (PTP) in autoimmune MRL/MpJ-lpr/lpr mice (lpr mice) were measured and compared with the activities in the tissues from MRL/MpJ-+/+ mice (+/+ mice) as the control. In the spleen and liver, PTK activities in cytosol and membrane fractions were about 1.7- and 1.3-fold, respectively, higher in lpr mice than +/+ mice. PTP activities in cytosol and membrane fractions from lpr mice were 1.7- and 1.3-fold, respectively, higher in spleen, and 2.5- and 1.3-fold, respectively, higher in liver compared with those of the controls. These results demonstrate that the mutation of lpr gene resulted in elevation of PTK and PTP activities. Then, we measured the amounts and activities of SH-PTP1, a cytosolic PTP playing a crucial role in intracellular signaling from Fas antigen. The amounts of SH-PTP1 were about 4-fold larger in thymus, spleen, and lymphnodes than in liver, but there was no marked difference in the amounts between lpr and +/+ mice. On the other hand, activity of SH-PTP1 was definitely lower in lpr spleen and lymphnodes than +/+ spleen, but several times higher in lpr liver than +/+ liver. Tyrosine phosphorylation levels of SH-PTP1 in spleen of lpr and +/+ mice were similar. However, in liver, it was less phosphorylated in lpr than in +/+ mice. This hypophosphorylation might cause the activation of SH-PTP1 activity in lpr liver.

Animals↗

[Basic and clinical studies of pazufloxacin on infectious enteritis research group of T-3761 on infectious enteritis].

A clinical study was carried out on pazufloxacin (PZFX) in 137 patients including shigellosis, Salmonella enteritis, enteropathogenic Esherichia coli enteritis and cholera, and carriers of these pathogens. Antibacterial activity of PZFX against clinical isolates, fecal concentration of PZFX and effects of PZFX on fecal microflora were also investigated. The overall clinical efficacy rate was 97.2%. The bacteriological efficacy rates were 98.2% against Shigella spp., 81.8% against Salmonella spp., 50% against Vibrio cholerae O1, and 100% against E. coli, V. parahaemolyticus, Aeronomas spp., Plesionomas shigelloides and V. cholerae non-O1, respectively. Side effect (epigastralgia) was observed in 1 of 130 cases (0.8%). The rate of abnormal laboratory findings was 11.2% (11/98). These were mainly elevation of GOT and/or GPT and increased eosinophils. The clinical usefulness rate was 95.2%. The MIC90 values of PZFX against Shigella spp., Salmonella spp. and E. coli were 0.025, 0.025 and 0.025 micrograms/ml, respectively. The results of fecal drug concentration and the effects on fecal microflora in one patient were compatible with those obtained in healthy volunteers.

4-Quinolones↗

Evaluation of the somatosensory evoked blink response in patients with neurological disorders.

BACKGROUND: The somatosensory evoked blink response (SBR) is a characteristic reflex blink elicited by electrical stimulation of peripheral nerves or other anatomical sites. METHODS: 139 patients with neurological disorders were examined for presence of the SBR. Although the SBR was not usually elicitable, it was present in a subset of patients with Parkinson's disease and with hemifacial spasm. It was also present in a patient with Guillain-Barré syndrome before the recovery phase. The latency of the EMG activities responsible for the SBR was significantly shorter than that of the startle blink. CONCLUSIONS: The SBR is not a variant of the startle blink, but is a release phenomenon transmitted via the brainstem reticular formation. This response may be clinically relevant in disorders associated with brainstem lesions and abnormal blinking.

Blinking↗

Eight-year follow-up study of bromocriptine monotherapy for Parkinson's disease.

An 8-year nationwide study of bromocriptine monotherapy and combination therapy with bromocriptine and levodopa in Parkinson's disease is reported. Fifteen patients were on bromocriptine monotherapy, and 44 patients on bromocriptine combined with levodopa for a certain time during an 8-year period. By judging from Hoehn and Yahr's grading, 4 of the 15 patients in the monotherapy group were in a better condition than before treatment, while 7 cases remained in the same grading, and only 4 showed deterioration. On the other hand, 26 of 44 patients on combination therapy showed more advanced grading at the end of 8 years compared to the stage at the onset of the trial. Maintenance doses of bromocriptine in the two groups were 12-13 mg per day, and levodopa doses were kept at a relatively low level (310-370 mg per day) during this study period. Whether dopamine receptor agonists have neuroprotective effect or not is extremely difficult to prove in human subjects, but this type of long-term follow-up study might give some clues as to these important questions.

Aged↗

Thalamic tremor: case reports and implications of the tremor-generating mechanism.

We report two patients with unilateral resting and postural tremor of the upper limb as a delayed manifestation of thalamic stroke. Neuroradiologic examination showed a lesion in the posterolateral thalamic region in both patients, but with no obvious involvement of the brainstem, the cerebellum, or the cerebellar outflow tract to the thalamic ventrolateral nucleus.

Adult↗

Distribution of dystrophin and dystrophin-associated protein 43DAG (beta-dystroglycan) in the central nervous system of normal controls and patients with Duchenne muscular dystrophy.

In skeletal muscles of patients with Duchenne muscular dystrophy (DMD), the absence of dystrophin was thought to lead to the large reduction in all of the dystrophin-associated proteins (DAPs). Of the seven types of DAPs identified in skeletal muscle, only the 43-kDa glycoprotein (beta-dystroglycan) has recently been found in the monkey brain. To clarify the distribution and characterization of dystrophin and beta-dystroglycan in the brain of humans, we carried out immunostaining and immunoblotting studies on tissues from three DMD patients with intellectual disturbances (ages 17,22, and 26 years) and in five controls (age range, 42-74 years). An antidystrophin antibody revealed dystrophin to be localized in neuronal cells and in the vascular wall in control brains, but it was absent from these tissues in DMD patients. In contrast, beta-dystroglycan was distributed throughout neuronal cells and in the vascular wall of control brains, and was well preserved in the brain of patients with DMD.

Adolescent↗

[A long-term clinical effect of selegiline hydrochloride on Parkinson's disease].

A long-term follow-up evaluation on the clinical usefulness of selegiline hydrochloride (selegiline) was performed in 13 patients with Parkinson's disease. All patients, except one case, subjected to the study were symptomatically improved by combination therapy of selegiline with L-DOPA in the preceding short-term evaluation. One patient continued the therapy after an evaluation of no symptomatic improvement in the short-term study, because this patient strongly requested continuation of medication, expecting to stop the progression of the disease. The average daily dose of selegiline at the last evaluation was 7.0 +/- 2.8 mg. The average daily dose of L-DOPA at each evaluation point in the patients who continued the therapy for 12 months remained low compared to that prior to the therapy (before: 450 +/- 138 mg, at the 12th month: 383 +/- 98 mg). In the analysis of individual parkinsonian symptoms, the improvement in the mean score for most of the symptoms, especially the wearing-off phenomenon and frozen gait, persisted for the entire period of study. Global improvement rates (moderately improved) at the 6th and 12th month, and the last evaluation were 60.0%, 50.0% and 50.0%, respectively. Among 10 patients, therapy was discontinued only in one case due to hallucination. Although the global improvement rate declined in the course of the therapy, selegiline seems to be useful for improving L-DOPA responsive symptoms in long-term therapy for Parkinson's disease.

Aged↗

[A 78-year-old man with young onset parkinsonism and sudden death].

We report a right-handed 78-year-old man with early onset parkinsonism. The patient had an onset of micrographia at 23 years of the age in 1939. Seven years later he started to drag his right foot, and at 38 years of age, he walked with small steps with festination. Tremor was also present in his right hand. His daily life was independent as a otorhinolaryngologist. He visited our clinic on March 24, 1977 when he was mentally sound and showed mild parkinsonism consisting of masked face, stooped posture, small step gait, bradykinesia, and right side dominant rigidity and tremor. He showed good response to trihexyphenidyl and amantadine HCl. Two month later, he developed dyskinesia and some worsening of parkinsonism, and was admitted to our hospital for the first time. He was treated with 400 to 600 mg/day of levodopa/ carbidopa. He showed marked improvement, however, dyskinesia remained in his mouth. He was doing well until 77 years of age (June of 1993) when he developed hallucination and motor fluctuations. He was admitted again to our hospital on June 22, 1993. On admission, he was alert and appeared mentally sound. However, Hasegawa dementia scale was 18/30. Upward gaze was slightly restricted (3/5). Voice was somewhat small but no masking was noted. His posture was stooped and the gait was of small step. Dyskinesia was noted during walk. No rigidity nor tremor was noted. Deep tendon reflexes were lost but no sensory loss or motor weakness was noted. Routine laboratory studies were unremarkable. A cranial CT scan revealed only mild to moderate cortical atrophy. Motor and sensory conduction velocities were within normal limits, however, motor action potentials could not be obtained with stimulation to the right common peroneal nerve. He was treated with 600 mg/day of levodopa with carbidopa, 100 mg of amantadine HCl, 300 mg of Dops, and 25 mg of tiapride. He continued to show motor fluctuations, and was discharged on July 23, 1993. Since then his motor functions had become progressively worse with frequent falls, but he was still able to walk without support. On October 3 of 1994, he went to bed as usual. On the next morning, he was found dead in his bed at 9: 30. The patient was discussed in neurological CPC, and the chief discussant arrived at the conclusion that the patient had young-onset Parkinson's disease with Lewy bodies in the substantia nigra. Opinions were divided between Parkinson's disease and Lewy body negative young onset parkinsonism. Postmortem examination revealed obstruction of the trachea by aspirated foods, and the cause of death appeared to have been suffocation by the foods. Macroscopically, the external appearance of the brain was unremarkable except for slight frontal atrophy. The substantia nigra showed depigmentation in the lateral part, but the pigmentation of the medial part was well preserved. Upon histologic examination, the number of pigmented neurons in the dorsomedial part was well preserved. In the lateral part, pigmented neurons were well preserved in the dorsal area, however, in the ventral area, only non-pigmented neurons were seen; they appeared to be neurons in the pars reticulata. No gliosis was seen in any of the nigral areas. No Lewy bodies were seen in the remaining neurons. So-called immature neurons with rounded shape without neuromelanin could not be detected. The locus coeruleus neurons were well preserved. The putamen and the other basal ganglia structures were also intact. Slight myelin pallor was noted in the subcortical white matter, however, otherwise cerebral cortices were normal. The histology of this patient is unique in that only the ventrolateral part of the substantia nigra showed abnormal finding consisting of lack of pigmented neurons without gliosis. It is not clear whether the nigral change represents degeneration or a congenital "hypoplasia'. To our knowledge, such a unique pathology of the substantia nigra has not been reported in the literature. Our patient ma

Age of Onset↗

[The relationship between visual agnosia and visual pathway for perception].

We report a patient with a unique visual agnosia, who was thought to have lost visual functions except for the primary visual function. The patient was a 71-year-old woman with progressive memory loss and cerebro-cortical atrophy in MRI; her clinical diagnosis was senile dementia of Alzheimer's type. A battery of tests to detect higher visual dysfunctions was performed. First of all, we presented small dots and lines in front of the patient; the patient was able to recognize them. When a triangle, a tetragon, a cube, pieces of paper of different colors and lines of different length were presented, she was unable to recognize those objects. When pictures of her family members or filled circles of different size including small dots and lines were presented, the patient could only detect those small dots and any of lines; she could not recognize the members of her family. The cerebral blood flow was severely reduced in the occipital lobe except for the striate cortex. These data suggested that the visual function of striate cortex was preserved in this patient; the disturbance of higher visual functions was thought to be caused by the dysfunction of extra striate cortex.

Aged↗