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Biomedical subjects

F Matsuo

Publications and source records attributed to F Matsuo.

At least 19 recordsLinked to original sources
PubMed2004

Magnetoencephalographic spikes not detected by conventional electroencephalography.

OBJECTIVE: To investigate some of the reasons why magnetoencephalographic (MEG) spikes are at times not apparent in conventional electroencephalograms (EEG) when the data are co-registered, and to explore to what extent modern EEG analysis methods can improve the yield. METHODS: Seventy seconds of MEG-EEG co-registration on a 122 channel Neuromag system were studied in a 10-year-old boy with Landau-Kleffner syndrome. Twenty-six EEG channels were originally recorded with a left ear reference. The EEG data were subsequently reformatted (BESA) to a variety of montages for the 10-20 and 10-10 electrode array. A 10 s data epoch was compared in detail for concordance between MEG and EEG spikes. To detect the characteristics of hidden low voltage EEG spikes, MEG spikes were averaged and compared with the concomitant averaged EEG spike. RESULTS: While there was an abundance of EEG as well as MEG spikes on the left; definite right-sided spikes were not visible in the EEG. Right hemispheric MEG spikes were, however, plentiful with an average strength of 757 fT. When the individual MEG spikes from the right hemisphere were compared with the corresponding EEG events their amplitude ranged between 24 and 31 microV and were, therefore, indistinguishable from background activity. The majority of them became visible, however, with further sophisticated data analysis. CONCLUSIONS: When the relative merits of MEG versus EEG recordings for the detection of epileptogenic spike are investigated the 10-20 system of electrode placement and conventional methods of EEG analysis do not provide optimal data assessment. The use of the 10-10 electrode array combined with modern methods of digital data analysis can provide better concordance with MEG data.

Child↗
PubMed2000

Nuclear localization signals of the BRCA2 protein.

BRCA2 is a tumor suppressor gene whose germline mutations increase the lifetime risk of breast cancer. BRCA2 encodes a large nuclear protein involved in DNA repair, but the location of its functional domain has been unclear. Here, we report nuclear localization signals (NLSs) of the BRCA2 protein. By expressing various portions of the BRCA2 protein tagged with enhanced green fluorescent protein in HeLa cells, we show that the C-terminal domain is necessary for nuclear localization. Two regions in the C-terminal domain were identified with functional NLSs by site-directed mutagenesis analyses. The NLSs locate between the germline mutation found in the most downstream position and the polymorphic stop codon, suggesting that defects in the proper nuclear transport of the BRCA2 protein are causative of carcinogenesis. Our data thus provide a possible explanation for the high frequency of frame-shift and nonsense mutations in BRCA2 of hereditary breast cancer patients.

BRCA2 Protein↗
PubMed2000

Identification of Rad51 alteration in patients with bilateral breast cancer.

The human Rad51 gene, HsRAD51, is a homolog of RecA of Escherichia coli and functions in recombination and DNA repair. BRCA1 and BRCA2 proteins form a complex with Rad51, and these genes are thought to participate in a common DNA damage response pathway associated with the activation of homologous recombination and double-strand break repair. Additionally, we have shown that the pattern of northern blot analysis of the RadS gene is closely similar to those of the BRCA1 and BRCA2 genes. It is therefore possible that alterations of the Rad51 gene may be involved in the development of hereditary breast cancer. To investigate this possibility, we screened Japanese patients with hereditary breast cancer for Rad51 mutations and found a single alteration in exon 6. This was determined to be present in the germline in two patients with bilateral breast cancer, one with synchronous bilateral breast cancer and the other with synchronous bilateral multiple breast cancer. In both patients, blood DNAs showed a G-to-A transition in the second nucleotide of codon 150, which results in the substitution of glutamine for arginine. As this alteration was not present in any patients with breast or colon cancer examined, we assume that this missense alteration is likely to be a disease-causing mutation.

Blotting, Northern↗
PubMed1999

Lamotrigine.

Clinical use of the antiepileptic drug (AED) lamotrigine (LTG) has dramatically increased since its introduction in Europe in 1991 and in the United States in 1994. This article surveys the English-language literature of LTG published before 1998. This literature is concerned with the molecular mechanisms of LTG's antiepileptic action, evaluation of its clinical antiepileptic efficacy, adverse experiences associated with its clinical use, and current guidelines for its initiation. LTG's efficacy has been extensively confirmed in multiple postmarketing studies, and its applications are broad. The most serious adverse experiences have involved skin rash. Valproic acid affects LTG metabolism, and a specific set of guidelines for the concurrent use of valproic acid and LTG has been developed. Unique issues are also associated with its pediatric use. LTG has a significant place in clinical management of a wide range of epilepsy syndromes, and the scope of its use is expanding. Accumulating clinical data enable the clinician to maximize its efficacy and minimize adverse experiences. Guidelines for its pediatric use must be followed diligently.

Adolescent↗
PubMed1999

The fungicide carbendazim induces meiotic micronuclei in the spermatids of the rat testis.

Whether the fungicide carbendazim affects the meiotic spermatocytes and consequently induces chromosome aberrations in the spermatids was determined in the adult rat testis using the micronucleus test. Round spermatids containing micronuclei (MN) were significantly increased in number at stages I and V on days 1 and 4.5 after treatment with carbendazim (100 mg/kg), respectively (p<0.05). Immunocytochemistry indicated that approximately 68% of the carbendazim-induced MN contained kinetochores. These results suggest that carbendazim induces chromosome aberrations in spermatids with a high incidence of aneuploidy.

Animals↗
PubMed1998

A comparison of rectal diazepam gel and placebo for acute repetitive seizures.

BACKGROUND: Acute repetitive seizures are readily recognizable episodes involving increased seizure frequency. Urgent treatment is often required. Rectal diazepam gel is a promising therapy. METHODS: We conducted a randomized, double-blind, parallel-group, placebo-controlled study of home-based treatment for acute repetitive seizures. Patients were randomly assigned to receive either rectal diazepam gel, at a dosage varying from 0.2 to 0.5 mg per kilogram of body weight on the basis of age, or placebo. Children received one dose at the onset of acute repetitive seizures and a second dose four hours later. Adults received three doses -- one dose at onset, and two more doses 4 and 12 hours after onset. Treatment was administered by a care giver, such as a parent, who had received special training. The number of seizures after the first dose was counted for 12 hours in children and for 24 hours in adults. RESULTS: Of 125 study patients (64 assigned to diazepam and 61 to placebo) with a history of acute repetitive seizures, 91 (47 children and 44 adults) were treated for an exacerbation of seizures during the study period. Diazepam treatment was superior to placebo with regard to the outcome variables related to efficacy: reduced seizure frequency (P<0.001) and improved global assessment of treatment outcome by the care giver (frequency and severity of seizures and drug toxicity) (P<0.001). Post hoc analysis showed diazepam to be superior to placebo in reducing seizure frequency in both children (P<0.001) and adults (P=0.02), but only in children was it superior with regard to improvement in global outcome (P<0.001). The time to the first recurrence of seizures after initial treatment was longer for the patients receiving diazepam (P<0.001). Thirty-five patients reported at least one adverse effect of treatment; somnolence was the most frequent. Respiratory depression was not reported. CONCLUSIONS: Rectal diazepam gel, administered at home by trained care givers, is an effective and well-tolerated treatment for acute repetitive seizures.

Acute Disease↗
PubMed1998

Incidence of spikes and paroxysmal rhythmic events in overnight ambulatory computer-assisted EEGs of normal subjects: a multicenter study.

The incidences of spikes and paroxysmal rhythmic events (PREs) in 10-h overnight EEGs of normal adult volunteers (n=135) were studied at 11 sites with a computer-assisted ambulatory EEG monitoring system with automatic spike and PRE detection. Spikes were evident in the overnight EEG of 1 subject (0.7%), and PREs were apparent in the overnight EEG of the same subject (0.7%). The incidences of spikes of 24 other subjects with a history of migraine and/or a family history of epilepsy were 12.5 and 13.3%, respectively. The overnight EEGs of these subjects were significantly more likely to show spikes than the overnight EEGs of subjects without migraine or a family history of epilepsy.

Adolescent↗
PubMed1997

Further observations on carbendazim-induced abnormalities of spermatid morphology in rats.

The effects of a microtubule poison, carbendazim, on rat spermiogenesis were examined for abnormalities of nuclei, acrosome and manchette in round and elongating spermatids in Stages VII-XII on days 7.5, 9.5, 10.0 and 10.5 post-treatment using routine electron microscopy. Spermatid nuclear abnormalities were observed in Stages IX-XI on day 9.5 and at greater post-treatment intervals. Nuclear abnormalities included nuclear distortions, various types of nuclear invaginations and abnormal positioning of the modified nuclear envelope. Acrosomal abnormalities were noted on day 7.5 and at greater intervals. Discontinuous, multiple granular and fragmentary acrosomes were observed in Stages VII-XI. In addition, spermatids with complete absence of acrosome (acrosome-deficient spermatids) were observed in Stages VII-X. Poorly-formed and absent ectoplasmic specializations were seen in the cytoplasm of Sertoli cells next to the acrosome-deficient spermatids. A major abnormality of the manchette was irregular positioning of the manchette microtubules in steps 9-11 spermatids on day 9.5 and at greater intervals, which resulted in nuclear invagination. The results indicate that carbendazim induces abnormalities in spermatid morphology that are common to those reported in testes treated with several chemical compounds and in testes of mutant animals.

Acrosome↗
PubMed1996

Lamotrigine high-dose tolerability and safety in patients with epilepsy: a double-blind, placebo-controlled, eleven-week study.

PURPOSE: This study was undertaken to evaluate the dose tolerability and safety of a chronic ascending twice-daily (b.i.d.) dosage regimen of < or = 700 mg/day lamotrigine (LTG) and to include determination of the LTG pharmacokinetic profile at doses > or = 500 mg/day in patients receiving concomitant enzyme-inducing antiepileptic drugs (AEDs). METHODS: Twelve adult male epileptic patients treated with enzyme-inducing AEDs received < or = 700 mg/day (b.i.d.) oral LTG (n = 8) or placebo (controls, n = 4). For 3 weeks, as outpatients they had their LTG dosage increased from 100 to 400 mg/day. Then, in a clinical research study unit, patients received regimens of 500, 600, and 700 mg/day for 1 week each. Controls received matching placebo in the same sequence. At study end, dosages were tapered in 2 weeks. Follow-up evaluations were made 7 days later. RESULTS: Five LTG patients tolerated 700 mg/day for 1 week. LTG was reduced to 600 mg/day in a patient with mild diplopia and to 500 mg/day in a patient with mild oscillopsia and diplopia. One patient discontinued 300 mg/day therapy with a moderately intense diffuse papular skin rash, attributed to LTG. Headache, drowsiness, faintness, and diplopia, the common adverse events (AEs), were mild to moderate in intensity and occurred in 50-75% of patients in both groups (except for diplopia, occurring only with LTG). Concomitant AED plasma concentrations were not markedly changed by LTG. LTG pharmacokinetics were linear over the range of 500-700 mg/day. CONCLUSIONS: LTG doses < or = 700 mg/day can be tolerated in patients receiving concomitant enzyme-inducing AEDs.

Adolescent↗
PubMed1993

Placebo-controlled study of the efficacy and safety of lamotrigine in patients with partial seizures. U.S. Lamotrigine Protocol 0.5 Clinical Trial Group.

We evaluated the efficacy and safety of lamotrigine (300 and 500 mg/day) as add-on therapy in a multicenter, randomized, double-blind, parallel-group, placebo-controlled study of 216 patients with refractory partial seizures. During 6 months of treatment, median seizure frequency decreased by 8% with placebo, 20% with 300 mg lamotrigine, and 36% with 500 mg lamotrigine. Seizure frequency decreased by > or = 50% in one-third of the 500-mg group and one-fifth of the 300-mg group. Reductions in seizure frequency and seizure days were statistically significant, compared with placebo, for the 500-mg group but not the 300-mg group. Most adverse events were minor and resolved over time. Nine percent of patients on lamotrigine withdrew because of adverse experiences. Lamotrigine plasma concentrations appeared to be a linear function of dose, and the drug did not affect plasma concentrations of concomitant antiepileptic drugs. Lamotrigine was safe, effective, and well tolerated as add-on therapy for refractory partial seizures.

Adolescent↗
PubMed1992

Atypical herpes simplex encephalitis: clinical, virologic, and neuropathologic evaluation.

An atypical form of herpes simplex encephalitis produced by HSV-1 documented in the present article demonstrates that (1) prominent EEG abnormality may correlate with subtle increase in signal intensity on MRI; (2) the disease may start with prominent involvement of the cingulate gyri; and (3) viral infection of the brainstem may cause early onset of severe neurologic dysfunction and coma.

Brain Stem↗
PubMed1991

Expanded head surface EEG electrode array: an application to display the voltage topography of focal epileptiform discharges of mesiotemporal origin.

Aided by computerized voltage topographic display, conventional time-series EEG display methods were expanded. Representations of both negative and positive ends of an equivalent current dipole can be localized in EEG sampled over the head surface. Intuitive EEG analysis can be applied to source localization in three dimensions of scalp focal epileptiform discharges.

Adult↗
PubMed1986

Subarachnoid hemorrhage due to anterior spinal artery aneurysm.

This case report describes a 29-year-old man with subarachnoid hemorrhage due to an anterior spinal artery aneurysm. Surgical obliteration of the aneurysm was successful. This is the sixth reported case of an isolated symptomatic aneurysm of a spinal artery.

Adult↗
PubMed1985

EEG features of the apallic syndrome resulting from cerebral anoxia.

Three victims of severe cerebral anoxia developed the apallic syndrome, and clinical neurophysiological examinations documented slow evolution of a diurnal behavior pattern. Marked EEG attenuation was the primary finding, but all the patients exhibited clustering of quiescent periods at night, during which EEG waves were generated, and two stages suggested REM and non-REM sleep. The results seemed to confirm the notions that brain-stem mechanisms control occurrence of REM and non-REM sleep, and that forebrain mechanisms are required for development of differential EEG features of non-REM sleep stages (I through IV). It is also suggested that an extreme degree of attenuation resulting from EEG desynchronization in certain patients may closely resemble ECS.

Adult↗