Search PubMed⌕ Search

Biomedical subjects

H Nakase

Publications and source records attributed to H Nakase.

At least 127 records · Page 7Linked to original sources

Cortical and subcortical cavernous angioma: a comparison of patients with and without hemorrhage as the initial symptom.

Cavernous angioma is a benign vascular hamartoma with an obscure etiology. Clinical, radiological, and histological features of 24 cases of cortical and subcortical cavernous angiomas were analyzed to investigate the etiology. The lesions were classified as hemorrhaging (8 cases) or non-hemorrhaging (16 cases) according to the initial symptom. Age, sex, location, calcification and postcontrast enhancement by computed tomography (CT), tumor staining by angiography, and calcification and hemosiderin by histological examination were analyzed. Multivariate analysis showed that calcification by CT and histological examination correlated with non-hemorrhaging cases. Histological examination showed that calcification occurred inside and outside the blood vessels, within the vessel walls and in the adjacent brain tissue. Hemosiderin was also seen in most cases. These findings suggest that cavernous angiomas without hemorrhage have a poor circulation, resulting in minor recurrent bleeding and thrombosis, as well as calcification.

Adolescent↗

[Changes in seizure-triggering threshold and after discharge duration in seizure susceptibility].

Epilepsy is analysed on terms of two different conditions, seizure susceptibility and seizure induction. Reports on detailed changes of seizure-triggering threshold and after discharge duration in seizure susceptibility are few. We examined staged changes of seizure-triggering threshold and after discharge duration in seizure susceptibility in a cat amygdaloid kindling model. Ten crossed adult cats were used. We investigated after discharge threshold (ADT), partial seizure threshold (PST) in stage 4 group (P) and generalized seizure threshold (GST) in stage 6 group (C). At the same time, we examined after discharge duration on electroencephalograph (EEG) in each stage. Seizure-triggering threshold decreases significantly step by step. After discharge duration increases significantly step by step. It is concluded that staged decrease of seizure-triggering threshold and increase of seizure's grade and duration was seen in seizure susceptibility.

Amygdala↗

[Gene analysis of Japanese patients with familial amyloidotic polyneuropathy type IV].

Familial amyloidotic polyneuropathy type IV (FAP IV) is clinically characterized by slowly progressive cranial neuropathy and corneal lattice dystrophy. More than 300 cases were clustered in the Finnish population. Recent biochemical studies have demonstrated that the amyloid fibril protein in FAP IV is related to Asn-187 variant gelsolin, and the corresponding missense mutation, a G to A substitution at nucleotide 654 of plasma gelsolin cDNA, cosegregates with the disease phenotype in Finnish families. Here we analyzed the gelsolin gene of the Japanese family with FAP IV which we described as the first Japanese case. Direct sequence analysis of PCR-amplified DNA fragments spanning the codon 187 of plasma gelsolin cDNA from the 2 affected family members demonstrated a single base substitution, G to A at nucleotide 654, which is identical to the mutation of Finnish FAP IV. Restriction analysis using a modified PCR revealed that three unaffected family members and three unrelated healthy controls were homozygous for the normal allele, whereas the seven affected family members were heterozygous for the normal and the mutated alleles. This indicates the cosegregation of the mutation with the disease phenotype in this Japanese family, suggesting that the mutation causes the FAP IV phenotype regardless of ethnic background.

Alleles↗

[Wallenberg's syndrome due to vertebral artery dissection following minimal neck injury--report of two cases].

We described two cases of the lateral medullary syndrome (Wallenberg's syndrome) due to vertebral artery dissection following minimal neck injuries. The first case was a 45-year-old man, who hit his head and often rotated his head because of posterior neck discomfort. Two years after the injury, he suffered from sudden sharp neck pain, nausea, and vertigo, which was followed by left hand numbness and difficulty in walking due to the right lateral medullary syndrome. Angiography showed right vertebral artery dissection at the fourth segment. The second case, a 48-year-old man, suffered from neck pain immediately after he hyperextended his neck for painting a wall. Within several hours, he experienced left hand numbness and difficulty in walking due to the lateral medullary syndrome. Angiography showed a saccular aneurysm and dissection of the right vertebral artery at the fourth segment. In both cases, minor traumas were thought to be the causes of vertebral artery dissection. We surveyed previously reported 84 cases (men: 50, women: 34) of the vertebral artery dissection due to minor traumas. Seventy per cent of patients were in their third or fourth decade of life. The main causes of trauma preceding the dissection were neck manipulation especially chiropractics (52%). The third segment was most vulnerable. Delay in onset following neck trauma could be more than a week, but in most cases the delay was less than 24 hours. Cervical rotation and extension were thought to precipitate dissection.

Aortic Dissection↗

[Postoperative intracranial hemorrhage due to vitamin K deficiency: report of two cases].

Vitamin K deficient hemorrhagic diathesis is well known as a cause of infantile intracranial hemorrhage. Its occurrence, however, as a post-surgical complication is rare and has never been reported previously. Two cases are presented here which illustrate the existence of such a hazard. Case 1. A 73-year-old woman admitted with subarachnoid hemorrhage (WFNS IV) underwent microsurgical exploration of a left internal carotid aneurysm, and neck clipping of the aneurysm was performed. She had an uneventful postoperative course, but her neurological condition deteriorated suddenly on the fifth postoperative day. CT scan revealed a large epidural hematoma. Case 2. A 6-year-old boy was admitted due to the dysfunction of a ventriculo-peritoneal shunt system that had previously been placed for hydrocephalus. This dysfunction was thought to be caused by meningitis. Twelve days after ventricular drainage and antibiotic therapy, sudden intraventricular hemorrhage occurred. In both cases, PT and APTT were markedly prolonged, FDP slightly increased and fibrinogen slightly decreased. SFMC was positive in case 2. After the administration of vitamin K, PT and APTT were immediately normalized. Recent reports emphasize the adverse effect of antibiotics that leads to vitamin K deficient hemorrhagic diathesis, especially, in patients in a cachectic state. In these two cases, such a cachectic condition was not observed. We presume that the cause of vitamin K deficiency would be, along with the administration of antibiotics, a preliminary condition of disseminated intravascular coagulation which is encountered in some neurological disorders including subarachnoid hemorrhage. We conclude that attention should be paid for these pitfalls in perioperative neurosurgical care.

Aged↗

Biochemical and molecular analysis of cytochrome c oxidase deficiency in Leigh's syndrome.

We studied three patients with Leigh's syndrome (LS) and cytochrome c oxidase (COX) deficiency. Biochemical studies in brain, muscle, heart, liver, kidney, and fibroblasts disclosed a generalized COX deficiency. Kinetic studies of COX activity in brain mitochondria showed a low Vmax and a normal Km for reduced cytochrome c. Immunologic studies showed decrease of all COX subunits studied, without a specific defect of any one of them. Southern blot analysis excluded large deletions of mitochondrial DNA (mtDNA) but revealed a generalized increase in mtDNA quantity. Although Northern blot analysis showed no alteration in the 12 COX subunit mRNAs studied, two of three patients showed a decreased steady state rate of COX transcription in brain. COX deficiency in LS thus appears to be related to a decreased amount of otherwise normal COX holoenzyme.

Biochemistry↗

Partial corpus callosotomy beneficial for Lennox-Gastaut syndrome--report of two cases.

Seizures in patients with Lennox-Gastaut syndrome are very resistant to drug therapy. Division of the anterior half of the corpus callosum was performed in two patients with Lennox-Gastaut syndrome incapacitated by frequent atonic seizures leading to sudden falls. Postoperatively, the atonic seizures were completely eliminated and their mental reactivities remarkably improved. It is clear that they have benefited from a lower frequency of seizures and reduced dosages of anticonvulsant medication, which outweight the acquired disabilities.

Adult↗

Multiple calcified metastatic brain tumor--case report.

The authors describe an unusual case of pulmonary small cell carcinoma with numerous calcified metastatic nodules of the brain in a 62-year-old female. Computed tomographic scanning and magnetic resonance imaging demonstrated these lesions with ring enhancement. Autopsy revealed about 30 calcified metastatic nodules in the brain, but no calcification in the pulmonary lesion. Histological examination of the brain lesions disclosed necrosis and calcification in the center and small cell carcinoma cells in the periphery.

Brain Diseases↗

Mitochondrial encephalomyopathies: biochemical approach.

Thanks to recent advances in the molecular genetics of mitochondrial encephalomyopathies, we can now begin to correlate genetic lesions with biochemical defects. In the fatal infantile myopathy due to cytochrome c oxidase (COX) deficiency, an autosomal recessive condition, immunocytochemical studies have shown an isolated defect of subunit VIIa, which is 1 of the only 2 tissue-specific subunits of human COX. In muscle biopsies from patients with Kearns-Sayre syndrome, a multisystem disorder characterized by deletions of the mitochondrial DNA (mtDNA), the activities of all mitochondrial enzymes containing mtDNA-encoded subunits are decreased. The results of Northern analysis, in situ hybridization, and immunocytochemistry in muscle, and of mitochondrial protein synthesis in cultured fibroblasts suggest that partially deleted mtDNAs are transcribed but not translated, probably due to lack of indispensable tRNAs.

Brain Diseases↗

[Sequential changes in content of excitatory amino acids in the epileptic focus during seizure].

Recently much attention has been paid to excitatory amino acids in seizure susceptibility and induction. In order to examine the relationship between epilepsy, especially seizure induction, and excitatory amino acids, we examined sequential change in content of excitatory amino acids in the epileptic focus by microdialysis system in a cat amygdaloid kindling model. Fifteen crossbred adult cats divided into three groups: a sham operation group (Sh) as the control, just after stage 4 group (S4), and just after stage 6 seizure group (S6). Under halothane anesthesia, Microdialysis probe was inserted to the kindled focus, the right amygdala, and glutamate and aspartate contents of extracellular fluid were measured from 15 minutes prior to 30 minutes after seizure by high performance liquid chromatography (HPLC). The probe was perfused with artificial cerebrospinal fluid at a flow rate of 2 microliters/min for 5 minutes. Before seizure, glutamate and aspartate concentration showed no significant changes in the S4 and S6 group compared with the Sh group. But after seizure, glutamate concentration was significantly higher in the S4 and S6 group temporally, while aspartate concentration was higher only in the S6 group temporally. Based on the results that the release of glutamate and aspartate do not change in seizure susceptibility, that glutamate is released in partial seizure, and that glutamate and aspartate are released in generalized seizure from the epileptic focus, excitatory amino acids are involved in seizure induction in a cat amygdaloid kindling.

Amino Acids↗

Progressive cytochrome c oxidase deficiency in a case of Leigh's encephalomyelopathy.

We report the morphological, biochemical, immunological, and genetic findings in a patient with the clinical characteristics of Leigh's disease due to multisystemic cytochrome c oxidase (CCO) deficiency. Muscle biopsy at 2 years and 5 months of age showed markedly decreased CCO and cytochrome a + a3, moderately decreased NADH-cytochrome c reductase to 46.3%, and generalized loss of immunologically detectable CCO subunits, but other respiratory chain enzyme proteins were normal. All the tissues examined at autopsy showed decreased activity of all respiratory chain enzymes except complex II. The decrease in cytochromes b and a + a3 were in harmony with decreased enzyme activities in complex III and IV (CCO), respectively. All immunologically detectable subunits of CCO in immunoprecipitation were uniformly decreased in the cardiac and skeletal muscles, but subunits 1 and 4 were selectively decreased in other organs except liver. No large deletion could be detected in the cardiac muscle mtDNA after digestion with restriction enzymes. These results suggest that the respiratory chain enzymes are variable in their activity and the amount of enzyme proteins decreases as the disease progresses.

Brain↗

Cytochrome c oxidase deficiency.

Cytochrome c oxidase (COX) is a complex enzyme composed of 13 subunits, three of which are encoded by the mitochondrial DNA (mtDNA). The other 10 subunits are encoded by the nuclear DNA, synthesized in the cytoplasm, and transported into the mitochondria. The complexity of the enzyme and its dual genetic control explain the heterogeneity of clinical phenotypes associated with COX deficiency. There are two major syndromes, one characterized by muscle involvement (fatal infantile or benign infantile myopathy), the other dominated by brain disease (Leigh syndrome, myoclonic epilepsy with ragged red fibers, Menkes' disease). Partial defects of COX have been shown in muscle of patients with progressive external ophthalmoplegia, either alone (ocular myopathy) or as part of Kearns-Sayre syndrome. Biochemical studies have documented either muscle-specific or generalized defects of COX; COX deficiency is reversible in the benign infantile myopathy. Immunologically detectable protein may be normal (benign myopathy) or variably decreased (fatal myopathy, Leigh syndrome). The subunit pattern of COX is normal by immunoblot in patients with fatal myopathy and Leigh syndrome; a disproportionate decrease of subunit II was seen in a patient with myoclonic epilepsy with ragged red fibers. Availability of the three mtDNA genes and of complementary DNA probes for eight of the 10 nuclear DNA-encoded subunits makes it possible to investigate the different diseases at the molecular level. Large deletions of mtDNA have been found in patients with ocular myopathy and Kearns-Sayre syndrome: the deleted mtDNA appear to be transcribed but not translated, thus explaining the partial COX deficiency.

Brain Diseases↗

Transcription and translation of deleted mitochondrial genomes in Kearns-Sayre syndrome: implications for pathogenesis.

Large-scale deletions of human mitochondrial DNA (mtDNA) have been described in a clinical subgroup of mitochondrial encephalomyopathies associated with progressive external ophthalmoplegia and ragged-red fibers in skeletal muscle, including cases of Kearns-Sayre syndrome (KSS). Since the decrease in the activities of mtDNA-encoded respiratory-chain enzymes did not seem to be correlated to the sites of the deletions, the role played by the mtDNA deletions in the pathogenesis of these disorders has been unclear. To address this issue, we studied transcription and translation of deleted mtDNA in two patients with KSS harboring two different deletions. We found that the deleted genomes were transcriptionally active in both cases. Analysis of translation in one of the patients showed that the "fusion" mRNA derived from the region spanning the deletion did not seem to be translated. Thus, the biochemical defects in KSS can be explained by a lack of translation of mtDNA-encoded respiratory-chain polypeptides in some mitochondria, which, in turn, is probably due to the lack of indispensable mtDNA-encoded tRNAs in these organelles. These results imply that deleted mtDNAs may be segregated from normal genomes in this group of diseases. It seems likely that the absence of translation in proliferating mitochondria containing partially deleted genomes plays a major role in the pathogenesis of these disorders.

Base Sequence↗

[Intraventricular arachnoid cyst appearing with attacks of orbital pain: case report and review of the literature].

While there have been 5 cases of intraventricular arachnoid cyst published in the literature, the occurrence in the anterior horn of the lateral ventricle has not been reported. We report a case of intraventricular arachnoid cyst of the anterior horn causing attacks of orbital pain. A 30-year-old man was admitted with frequent attacks of orbital pain on his right side. Neurological examination revealed no abnormality. Plain CT showed a cystic dilatation of the anterior horn of the right lateral ventricle, and enhanced CT showed a deviation of the septal veins to the left side. T1-weighted MRI demonstrated a low-intensity mass in the anterior horn of the right lateral ventricle, and T2-weighted image demonstrated the mass as having high intensity. PEG in the sitting position showed no filling of air into the right lateral ventricle due to obstruction of the right foramen of Monro. The patient underwent an operation under a diagnosis of intraventricular benign cyst. The cyst wall was subtotally removed and the right foramen of Monro was opened. Histological examination of the specimen showed an arachnoid membrane with prolific collagen fibers. From an embryological point of view, the arachnoid membrane is derived from the arachnoid cell. We think intraventricular arachnoid cysts to originate from the remnants of the arachnoid cell on the tela choroidea or on the choroid plexus like intraventricular meningiomas.

Adult↗

[Changes in content of excitatory amino acids in the brain and cerebrospinal fluid].

Recently epilepsy is analysed on terms of two different conditions, seizure susceptibility and seizure induction. Much attention has been paid to excitatory amino acids in these conditions. An examination was made of changes of glutamate and aspartate in the brain and cerebrospinal fluid (CSF) in a cat amygdaloid kindling model so as to determine whether excitatory amino acids are possibly involved in seizure susceptibility and seizure induction. Twenty crossbred adult cats were divided into four groups: a sham operation group (Sh) as the control, just after stage 4 seizure group (S4), just after stage 6 seizure group (S6), and stage 6 group 2 weeks after the last stimulation (S6-2W). CSF, blood and 13 individual brain regions were taken at 9 + 4 degrees C, and their glutamate and aspartate contents were measured by high performance liquid chromatography (HPLC). Glutamate concentration was significantly higher in the S6 group than in the Sh group in CSF and less in the S6 group than in the Sh group in the left and right amygdala, hippocampus and piriform cortex. No aspartate could be detected in the CSF of any group, nor did it change significantly in the blood or brain. Based on the above results, the content and release of glutamate and aspartate apparently do not change in seizure susceptibility and glutamate is released from kindled tissues in seizure induction, thus showing it to be involved in seizure induction in a cat amygdaloid kindling.

Animals↗