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Biomedical subjects

M Fukui

Publications and source records attributed to M Fukui.

At least 145 records · Page 8Linked to original sources
PubMed1999

Serial MRI of cerebral infarcts before and after removal of an atrial myxoma.

We describe a cerebral infarct caused by atrial myxoma. A 30-year-old woman with an atrial myxoma presented with a right hemisensory deficit. MRI carried out before and after removal of the myxoma, showed multiple small bilateral white-matter infarcts which increased in number up to the surgery. A lesion in the left thalamus, which enlarged and showed contrast enhancement 4 months before surgery, resembled an old cerebral infarct by the time the myxoma was removed. The number of lesions stopped increasing after surgery. We suggest that atrial myxomas should be removed even in asymptomatic patients, to prevent cerebral infarcts due to embolism of tumour or thrombus.

Adult↗
PubMed1999

Possible role of an endovascular provocative test in the diagnosis of glossopharyngeal neuralgia as a vascular compression syndrome.

We utilized endovascular provocative techniques to identify the indications for microvascular decompression surgery in a serious case of glossopharyngeal neuralgia. This is the first reported case in which an endovascular provocative test was applied for diagnosis of glossopharyngeal neuralgia as a vascular compression syndrome. A 68-year-old woman presented with severe paroxysmal facial pain which could not be controlled by medical therapy. Partial effectiveness to carbamazepine led us to wonder whether or not the selection of microvascular decompression surgery would be appropriate. Pre-operative angiography was performed. During the examination a microcatheter was inserted into the right posterior inferior cerebellar artery (PICA), and an attack of typical glossopharyngeal neuralgia occurred. The patient thus underwent microvascular decompression surgery. The PICA was verified to compress the glossopharyngeal nerve and therefore was moved to induce decompression. The patient has since experienced no further pain for one year postoperatively. The diagnosis of glossopharyngeal neuralgia is sometimes complex and it is difficult to select the most appropriate surgical modality. In such cases this endovascular provocative technique may thus be useful for making a definitive decision or microvascular decompression surgery.

Aged↗
PubMed1999

Functional imaging in periventricular nodular heterotopia with the use of FDG-PET and HMPAO-SPECT.

We analyzed the interictal [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FGD-PET) and single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime (HMPAO-SPECT) in two epileptic patients with periventricular nodular heterotopia (PNH). In both cases, we found both the glucose metabolism and the perfusion of PNH to be almost identical to those of the normal cerebral cortex. The metabolic activity and perfusion in the heterotopic gray matter in a subependymal white matter area probably represent the glucose metabolism and perfusion of the abnormally located gray matter rather than a subclinical ictal phenomenon. FDG-PET and HMPAO-SPECT were thus found to be a useful complement to magnetic resonance imaging in the evaluation of PNH.

Adult↗
PubMed1999

Fibroxanthoma arising from the cranial dura mater.

A primary xanthomatous tumor is very rare in the central nervous system (CNS). Here we report the case of a fibroxanthoma arising from the dura mater of the cerebrum that demonstrated no systemic disease or metabolic abnormalities. A 19-month-old, otherwise healthy boy was found to have an enlarged head. Magnetic resonance imaging demonstrated a left occipital dural mass lesion and an enlarged left cerebral hemisphere with ipsilateral ventricular enlargement. Subtotal removal of the tumor was performed through the left parieto-occipital craniotomy. The tumor was composed of a central fibrous portion, a peripheral xanthomatous area, and a boundary. The peripheral area of the tumor showed abundant uniform xanthomatous cells with a thin fibrous stroma and the mass was diagnosed as fibroxanthoma involving the dura. This may represent a distinct category of tumor, which is different from the previously reported cases of fibrous xanthoma and fibrous histiocytoma. Intracranial xanthomatous tumors may be heterogeneous in their origin and histological features. However, further studies are needed to elucidate their clinical features, biological behavior, and optimal treatment strategies.

Brain Neoplasms↗
PubMed1999

Functional imaging in schizencephaly using [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime (HMPAO-SPECT).

We analyzed interictal [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FGD-PET) and single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime (HMPAO-SPECT) in a 23-year-old female with schizencephaly. She had epilepsy and mild left hemiparesis, but was otherwise developmentally normal. We found the glucose metabolism and perfusion of the wall of the schizencephalic cleft to be identical to those of normal cerebral cortex. The wall of the transcerebral clefts, which were observed to be lined by abnormally organized gray matter as a result of a migration disorder, demonstrated gray matter metabolic activity and perfusion. FDG-PET and HMPAO-SPECT were thus found to be a useful complement to magnetic resonance imaging for evaluating schizencephaly.

Adult↗
PubMed1999

Combining steady-state constructive interference and diffusion-weighted magnetic resonance imaging in the surgical treatment of epidermoid tumors.

We describe the usefulness of three-dimensional Fourier transformation-constructive interference in steady-state (CISS) imaging and diffusion-weighted imaging (DWI) in the pre- and postoperative magnetic resonance imaging evaluation of intracranial epidermoid tumors. Two surgically proven epidermoid tumors in the cerebellopontine (CP) angle were not identified in conventional T1- and T2-weighted images because of a signal intensity similar to that of cerebrospinal fluid (CSF). CISS images clearly demonstrated displacement of the cranial nerves and a shift caused by a lesion in the cistern, but the signal intensity of the tumor by CISS was not sufficiently different from that of CSF to demonstrate the tumor directly. Using DWI, the tumor in the cistern was shown clearly by its increased signal intensity. Together, CISS and DWI compensated for each other's disadvantages, and this combination was useful in guiding surgical treatment of epidermoid tumors in the CP cistern.

Adult↗
PubMed1999

Influence of TNF microsatellite polymorphisms (TNFa) on age-at-onset of insulin-dependent diabetes mellitus.

The TNF-alpha gene is located in the HLA region and has been implicated in the pathogenesis of Type I (insulin-dependent) diabetes mellitus (IDDM). We investigated the frequency of TNFa microsatellite alleles in 76 young-onset IDDM patients, 65 adult-onset IDDM patients, and 90 control subjects. We also examined the association of these TNFa alleles with HLA-DRB1 alleles, HLA-class I alleles, and TNF-alpha production. The frequency of the TNFa2 and TNFa9 alleles was increased in the young-onset IDDM patients compared to control subjects, but the increased frequency of TNFa2 was not significant after the correction for the number of comparisons was made. We did not find any association of TNFa2 or TNFa9 with any of the HLA-DRB1 alleles. In contrast, the frequency of the TNFa13 allele was decreased in both the young-onset and the adult-onset IDDM patients compared to the control subjects, but the difference lost significance after the correction was made in the adult-onset IDDM. The TNFa13 allele was strongly associated with DRB1*1502. Patients with TNFa2 or TNFa9 had greater TNF-alpha production, while those positive for TNFa13 had lower TNF-alpha production than patients with non-TNFa2, a9, and a13 alleles. These results suggest that TNFa polymorphisms are associated with age-at-onset of IDDM and influence the inflammatory process of pancreatic beta cell destruction in the development of IDDM.

Adolescent↗
PubMed1999

Intrinsic epileptogenicity of focal cortical dysplasia as revealed by magnetoencephalography and electrocorticography.

Focal cortical dysplasia (FCD) is often associated with severe partial epilepsy. In this study, we performed magnetoencephalography (MEG) and electrocorticogrsphy (ECoG) on four patients with FCD-associated epilepsy to confirm the 'intrinsic' epileptogenicity of FCD. In all patients, we determined the three-dimensional locations of the magnetic sources of the interictal paroxysmal activities by a single dipole model, and then the estimated dipole localization was superimposed on the magnetic resonance image. The dipole clusters were located in the T2-prolonged lesions, namely in the FCD lesions themselves. All patients underwent surgery for their medically intractable epilepsy, and the acute and/or chronic ECoG were thereafter recorded. Either frequent or continuous paroxysmal activities were recorded from the ECoG electrodes which were placed over the surface of the FCD lesion, while few paroxysmal activities were observed on the normal appearing adjacent cortex. Intraoperative depth recordings were performed in a patient with the needle electrode inserted into the FCD lesion and they revealed these paroxysmal foci to be located not on the cortical surface but at a depth of 15 mm from the cortical surface where both abnormal giant neurons and bizarre large eosinophilic cells (so-called balloon cells) were also prominently observed on the postoperative histological sections. Following a lesionectomy combined with the removal of the underlying white matter, three patients demonstrated a favorable seizure outcome. Our findings thus suggest the FCD lesions to be highly and intrinsically epileptogenic lesions.

Adult↗
PubMed1999

Distribution of brainstem somatosensory evoked potentials following upper and lower limb stimulation.

OBJECTIVE: Because somatosensory evoked potentials (SEP) to lower limb stimulation have not been recorded from the brainstem to the extent that upper limb SEPs have been studied, we compared brainstem recordings in response to both median nerve (MN) and posterior tibial nerve (PTN)stimulation. METHODS: SEPs were recorded directly from the dorsal surface of the brainstem in four patients with fourth ventricle tumors. RESULTS: Following MN stimulation, medullary SEPs were characterized by a major negativity (N1) preceded by a small positivity (P1) and followed by a large positivity (P2). In the pons, triphasic waves with predominant negativity were obtained. With PTN stimulation, similar medullary SEPs with a P1'-N1'-P2' configuration and pontine SEPs with a triphasic waveform were obtained. CONCLUSIONS: Since the distribution of PTN SEP was identical to that of MN SEP, PTN SEPs are thought to be generated by mechanisms similar to those for MN SEP. Thus, the P1' and N1' of medullary SEP would be generated by the dorsal column fibers that terminate in the nucleus, with P2' possibly arising postsynaptically in the nucleus. The triphasic PTN SEP from the pons reflects an axonal potential generated in the medial lemniscal pathway.

Adult↗
PubMed1999

Selective transvascular delivery of oligodeoxynucleotides to experimental brain tumors.

Optimal therapeutic strategy for malignant brain tumors is controversial. Recent studies of viral or nonviral gene therapy in rats emphasize the need for a selective delivery system. We examined whether phosphorothioate oligodeoxynucleotides (lacZ 2157, 5'-GTGGCGTCTGGCGGAAAACC-3') could be selectively delivered transvascularly into experimental brain tumors following intracarotid infusion of bradykinin, a specific blood-tumor barrier opener. The specificity of 32P-labeled complementary antisense lacZ 2157 and the stability of lacZ 2157 in vivo were confirmed using slot-blotting hybridization method and polyacrylamide gel electrophoresis. Concentrations of lacZ 2157 after intracarotid injection (2 mg/kg, 10 microg/kg/min) with or without bradykinin were determined in the brain, tumor tissue, liver, kidney, and plasma. The transfer ratio of lacZ 2157 from the plasma to the tissues was calculated and expressed as tissue content relative to plasma content of lacZ 2157 per mg tissue (Do, microl/mg). Delivery of lacZ 2157 to tumor tissue increased 3.24 times with bradykinin over delivery in controls (0.0243 +/- 0.0176 vs. 0.00750 +/- 0.00389; p < 0.05). Delivery of lacZ 2157 to ipsilateral and contralateral cerebral cortex to the tumor, and delivery to the contralateral basal ganglia, did not increase significantly with bradykinin. These results indicate that such transvascular delivery with bradykinin can deliver a relatively large amount of oligodeoxynucleotide selectively to brain tumors without affecting normal brain.

Animals↗
PubMed1999

Overproduction of elongation factor 1alpha, an essential translational component, causes aberrant cell morphology by affecting the control of growth polarity in fission yeast.

BACKGROUND: Elongation factor 1alpha (EF1alpha), an essential component of the eukaryotic translational machinery, has been shown to possess various biochemical and biological activities, including F-actin-binding and -bundling, microtubule- severing, and the activity of making fibroblasts highly susceptible to transformation. However, our understanding of the biological significance of EF1alpha with respect to these various biochemical or biological activities remains limited. Here we report the identification of EF1alpha-encoding genes as genes whose over-expression causes aberrant cell morphology in fission yeast. RESULTS: Overproduction of EF1alpha caused aberrant cell morphology-elliptic, curved or branched-and growth defects in yeast cells at high temperatures. EF1alpha-overproducing cells showed a supersensitivity to the actin inhibitor cytochalasin D and to the tubulin inhibitor thiabendazole. Genetic analyses using cdc mutants suggested that excess EF1alpha disturbed the establishment and the maintenance of growth polarity in the G1 phase by pre- venting the localization of F-actin to the polarized growing site and the organization of microtubules. Results from DNase I column chromatography indicated that EF1alpha was bound to G-actin. Indeed, the fission yeast actin was immunoprecipitated along with EF1alpha. Moreover, the temperature sensitivity caused by the overproduction of EF1alpha was restored by co-overproduction of actin. CONCLUSIONS: Fission yeast EF1alpha has the ability to alter the cell morphology of yeast by affecting the control of actin and microtubule cytoskeletons.

Actins↗
PubMed1999

Immunohistochemical expression of trk receptor proteins in focal cortical dysplasia with intractable epilepsy.

Focal cortical dysplasia (FCD), which is often associated with intractable epilepsy, is a form of abnormal structure of the cerebral cortex caused by a disorder of normal neocortical development. In such cerebral lesions obtained from four patients (two male, two female; average age 32.3 years at operation), the immunohistochemical expression of Trk receptors, which interact with neurotrophins and result in both growth and maturational changes in neuronal cells, was investigated in relation to the possible histogenesis of these lesions. In all cases, a derangement of the cortical laminar structure, dysplastic cytomegalic neurones, and large round balloon cells were the characteristic histological features. Immunohistochemically, the TrkA expression was localized in large dysplastic cytomegalic neurones, and TrkB expression was observed in large dysplastic and relatively small neuronal cells within the affected cortex. Although the exact roles of neurotrophins and their receptors in the pathogenesis of FCD remain uncertain, its development might be governed by such neurotrophic influences, and thus possibly prevent the death of abnormal neuronal cells. In addition, Trk receptors in FCDs may also play a role in establishing in the intrinsic epileptogenicity of FCDs.

Adult↗
PubMed1999

Pituitary abscess secondary to isolated sphenoid sinusitis.

Intracranial complications from isolated sphenoid sinusitis are rare but nevertheless demonstrate both a high morbidity and mortality. We herein report a case of a pituitary abscess secondary to sphenoid sinusitis in a 12-year-old boy. This patient presented with an acute onset of moderate fever and headache, followed by progressive right ptosis. An emergency endoscopic endonasal sphenoidotomy with sinus drainage and postoperative antibiotic therapy resulted in a satisfactory recovery.

Brain Abscess↗
PubMed1999

Role of inducible nitric oxide synthase in the cerebral vasospasm after subarachnoid hemorrhage in rats.

The involvement of de novo nitric oxide synthase (NOS) induction in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) was examined using a rat model of SAH. SAH was induced by endovascular perforation with Nylon thread. The rats were killed at different time intervals, from one day to seven days after endovascular perforation. Inducible NOS messenger RNA (mRNA) expression was determined by reverse-transcription polymerase chain reaction (RT-PCR) and the distribution of iNOS positive cells was immunohistochemically examined. In the vascular tissue with a subarachnoid membrane, iNOS mRNA was expressed from one day to seven days after SAH. Inducible NOS positive cells were mainly recognized in the vascular tissue, but not in the brain parenchyma. The distribution of nitrotyrosine, an indicator of peroxynitrite production was also examined immunohistochemically and nitrotyrosine-positive cells were observed almost at the same sites of iNOS induction. To determine the role of iNOS in the development of cerebral vasospasm, we measured the diameter of the middle cerebral artery in animals either treated or not treated with aminoguanidine (AG), a selective inhibitor of iNOS. AG ameliorated the vasoconstrictive change after SAH. These results are thus considered to provide molecular and immunohistochemical evidence showing that iNOS expression following SAH and NO produced by iNOS can develop cerebral vasospasm after SAH.

Animals↗
PubMed1999

Effect of intracarotid bradykinin infusion on cerebral blood flow in dogs.

We examined whether intracarotid infusion of bradykinin altered circulation in the normal canine brain. Twenty-four anesthetized dogs were divided into four groups receiving different doses of bradykinin (1, 2.5, 5, and 10 micrograms kg-1 min-1). Regional cerebral blood flow (rCBF) was measured continuously using laser Doppler flowmetry through a burr hole in the frontal bone. Systemic blood pressure (SBP) and heart rate (HR) were monitored simultaneously. Higher doses of bradykinin significantly but temporarily decreased rCBF and SBP immediately after the start of infusion; these parameters rapidly recovered and then were stable through the rest of the infusion. During this period, percent change in rCBF and SBP was small, and differences between groups were not significant. On the other hand, HR increased during infusion and remained high. SBP, rCBF, and HR returned to pre-infusion levels after bradykinin was stopped. The results suggest that intracarotid infusion of bradykinin for treatment of brain tumors would be safe in terms of circulation to the uninvolved brain.

Animals↗
PubMed1999

Mapping of a familial moyamoya disease gene to chromosome 3p24.2-p26.

Moyamoya disease is characterized by bilateral stenosis and/or occlusion of the terminal portion of the internal carotid artery. Moyamoya disease is prevalent among patients <10 years of age. Although most cases appear to be sporadic, approximately 10% occur as familial cases. The incidence of familial cases has been increasing because noninvasive diagnostic equipment, such as magnetic-resonance imaging and magnetic-resonance angiography, can detect the disease in almost all affected patients, including asymptomatic patients, during screening studies. In this study, we performed a total genome search to identify the location of a familial moyamoya disease gene in 16 families, assuming an unknown mode of inheritance. A linkage was found between the disease and markers located at 3p24.2-26. A maximum NPL score of 3.46 was obtained with marker D3S3050. This is the first genetic locus found to be involved in the molecular pathogenesis of familial moyamoya disease.

Base Sequence↗
PubMed1999

Human chorionic gonadotrophin in CSF, not serum, predicts outcome in germinoma.

OBJECTIVES: Some intracranial germinomas, which may contain syncytiotrophoblastic giant cells (STGCs), are associated with a mildly to moderately increased human chorionic gonadotropin (HCG) concentration in serum, and patients with such germinomas are thus treated more aggressively than those with "pure" germinoma. However, the patients with germinoma and detectable HCG in CSF but not in serum have been classified and treated similarly to those with "pure" germinomas. The outcome of these patients and the relevance of HCG in the CSF were analysed. METHODS: The outcomes of patients with germinoma and increased serum HCG concentration (n=7) were compared with those of patients having detectable HCG titre in the CSF but not in the serum (n=5). RESULTS: Both groups in our series received similar treatments and also showed similar recurrence rates. The 40% recurrence rate in the group with HCG only in CSF did not correspond to the rate typical for "pure" germinoma: these tumours would be expected to have a better outcome. An additional patient whose CSF HCG were raised without increased serum HCG at recurrence is presented. CONCLUSIONS: It is recommended that patients with an increased HCG concentration in CSF should be considered to have "HCG producing germinoma", and they should be treated and followed up accordingly.

Adolescent↗