Biomedical subjects

H Yamanouchi

Publications and source records attributed to H Yamanouchi.

At least 37 records · Page 2Linked to original sources

PubMed2000

Cerebellar basket cells of Creutzfeldt-Jakob disease: immunohistochemical and ultrastructural study.

To elucidate possible abnormalities of cerebellar basket cells of Creutzfeldt-Jakob disease (CJD), seven sporadic cases were examined neuropathologically. Recently, parvalbumin-positive, GABAergic cerebral interneurons have been demonstrated to show early, selective loss in CJD, and the phenomenon is postulated as a cause of characteristic neurological symptoms of CJD. In this study, however, we demonstrated that the basket cells, cerebellar counterparts, were resistant even in patients with severe brain atrophy, and their processes showed intense argyrophilia and immunopositivity to phosphorylated neurofilament. They can newly be listed as CJD-resistant neurons similar to those of the hippocampus and brainstem nuclei. The mechanism to escape cell loss is of great interest, and there might be unknown factors modulating susceptibility within parvalbumin-positive neuronal subgroups. Furthermore, one case showed abnormal positivity with hematoxylin, crystal violet and pyronin in the basket cells. The pyronin positivity was reduced after ribonuclease digestion, suggesting that the causative substance was composed of RNA. Ultrastructurally, the fibers contained free ribosomes and amorphous electron-dense deposits. To our knowledge, such a finding has also not been previously reported.

Aged↗

PubMed2000

Novel cerebral lesions in the Eker rat model of tuberous sclerosis: cortical tuber and anaplastic ganglioglioma.

The Eker rat is a model for human tuberous sclerosis (TSC) caused by a mutation in the Tsc2 gene. We describe here histological and immunohistochemical findings of the brain lesions in Eker rats, with emphasis on 2 novel lesions found in this study: a cortical tuber and an anaplastic ganglioglioma. The rat cortical tuber resembled those of humans, and further confirmed the value of this animal model as a tool for investigating the molecular pathology of tuberous sclerosis. On the other hand, the rat anaplastic ganglioglioma had features of a malignant neoplasm that are absent from human subependymal giant cell astrocytomas.

Animals↗

PubMed2000

[A baby with shaken baby syndrome in whom early diagnosis resulted in good prognosis].

We encountered a 5-month-old baby with shaken baby syndrome, which had been caused by being thrown up about 50 cm in the air several times by his father. Intracranial hemorrhage, bleeding in the eye grounds in both eyes, and convulsion were noted on admission. Shaken baby syndrome was diagnosed from the history, and the patient was given necessary treatment, which led to favorable prognosis. Father was not aware of the danger of handling his baby in that way, and no sign of maltreatment was noted on the body surface of the baby. An attention should be payed that the danger leading into syndrome could be hidden among this kind of caring in the everyday life.

Cerebral Hemorrhage↗

PubMed1999

Olfactory bulb dysplasia: a novel subtype of neuronal migration disorder.

We present a novel subtype of neuronal migration disorder found in a case of Pena-Shokeir phenotype, in which the deformation sequence originated from neurogenic fetal akinesia. The autopsied brain showed dysplastic features of dentate and olivary nuclei as well as a bilaterally enlarged olfactory bulb with abnormal laminar structures. The laminar structures comprised four layers: (1) a superficial layer without glomeruli, (2) a neuronal cell layer containing neurons simulating mitral cells, (3) a sparse cell layer enriched with tangential neuronal fibers, and (4) a reticular layer showing a mottled appearance with the accumulation of fine reticular neurites intermingled with granule cells. To our knowledge, these malformed laminar changes have never been reported, and we propose the term olfactory bulb dysplasia.

Autopsy↗

PubMed1999

A case of well-differentiated, fetal-type hepatoblastoma with very low serum alpha-fetoprotein.

Serum alpha-fetoprotein (AFP) is elevated in 96.6% of infants and children with hepatoblastoma and hepatocarcinoma. Serum AFP was of normal level in only one case of immature-type hepatoblastoma, and very low in only one case of fetal-type hepatoblastoma among 43 cases reviewed in 1986. Recently, a case of hepatoblastoma with very low serum AFP was encountered in the authors' surgical department. In October 1998, a 55-month-old girl was admitted. Her birth weight was 717 g. A large space-occupying lesion (SOL) located in the left lobe of the liver was seen by magnetic resonance imaging (MRI), and her serum AFP level was 322 ng/mL with a subfractionation pattern of the "benign liver disease" type based on reactivity with lens culnaris hemagglutinin and concanavalin A. The patient underwent successful left lobectomy, and histological examination showed that the tumor, weighing 268 g, was hepatoblastoma of the well-differentiated, fetal type. Immunohistochemistry findings for AFP were negative. A hepatic mass in infants and children with low serum AFP level indicates the presence of either well-differentiated or immature hepatoblastoma, or fibrolamellar hepatocellular carcinoma. Subfractionation of AFP may contribute to the differential diagnosis of these subtypes.

Child, Preschool↗

PubMed1999

Pigmented squamous cell carcinoma with dendritic melanocyte colonization in the external auditory canal.

A case of pigmented squamous cell carcinoma (SCC) with dendritic melanocyte colonization in the external auditory canal is reported and the previous cases are reviewed. A 65-year-old Japanese female was referred with a 7-year history of otitis. The patient also had a darkly pigmented 9 x 8 mm nodule in the external auditory canal. Microscopically, the tumor was SCC, but in some areas melanin pigments were found in the cytoplasm of the tumor cells. The tumor was thus diagnosed as pigmented SCC. As well as the tumor cells, dendritic-shaped cells colonized the tumor parenchyma and were immunohistochemically defined as melanocytes. The authors believe this is the first case of pigmented SCC with dendritic melanocyte colonization in the external auditory canal.

Aged↗

PubMed1999

Glucocorticoids induce glutamine synthetase in folliculostellate cells of rat pituitary glands in vivo and in vitro.

Glutamine synthetase (GS) is a glucocorticoid-inducible enzyme that has a key role for glutamate metabolism in the central and peripheral nervous system. In this study GS activity was measured and the amount of immunoreactive GS (ir-GS) cells in the rat anterior pituitary gland was quantified as a function of age. In addition, the effects of GS inhibitors, glucocorticoid administration, and adrenalectomy on GS activity were examined. Some of the ir-GS cells were also immunoreactive for S100 protein (ir-S100) which is a known marker for folliculostellate cells (FS) in the anterior pituitary. FS cells expressing GS were first detected in 3-d-old rats, and this cell population, expressed as the immunostained cell area divided by a standard unit area, increased as a function of age. The percentages of FS cells also expressing GS were 0.2, 6.4, 25 and 74% at 3 d, 30 d, 60 d and 2 y of age, respectively. GS enzyme activity also increased in parallel with the increase of ir-GS cell population maturation. The subcutaneous injection of methionine sulphoximine, a GS and gamma-glutamylcysteine synthetase inhibitor, reduced pituitary GS activity by 83%, but increased the population of ir-GS cells 3.5-fold in 30-d-old rats. Buthionine sulphoximine, a specific inhibitor of y-glutamylcysteine synthetase, had little effect on GS activity or the ir-GS cell population. Neither methionine sulphoximine nor buthionine sulphoximine changed the population of ir-S100 protein cells (FS cells). Dexamethasone and hydrocortisone increased the population of ir-GS cells by 3.1 and 4.2-fold, respectively, within 12 h after administration. A significant increase of GS activity due to the injection of glucocorticoids was observed in the anterior pituitary, but not in the brain, retina or liver of immature rats. Adrenalectomy did not cause decrease of pituitary GS activity, and dexamethasone administration increased GS activity in both adrenalectomised and intact rats. In the monolayer culture of anterior pituitary cells, glucocorticoids increased GS activity by x 1.5, and methionine sulphoximine reduced the activity by over 94%. These results demonstrate that GS in folliculostellate cells is a glucocorticoid-inducible enzyme in vivo and in vitro, and that the age-dependent increase of GS activity is independent of endogenous adrenal glucocorticoids.

Adrenalectomy↗

PubMed1999

Polymorphous light eruption. A case report and consideration of the hardening mechanism.

BACKGROUND: Polymorphous light eruption (PLE) is a common form of photodermatosis. The pathogenesis of the disease and the mechanism of the hardening phenomenon, however, have not been clarified. OBSERVATION: We report a 62-year-old Japanese woman with PLE. Provocation and hardening induction testing revealed that hardening was induced at the sites irradiated by a sufficient dose of UV for reproduction of the lesion. Topical steroid could prevent a positive reaction but not the hardening induction. The expression of adhesion molecules and CD1a was decreased at the hardening site. CONCLUSION: From these results, the hardening phenomenon in our case might be due to immunosuppression by UV exposure supported by the down-regulation of cell adhesion molecule expression and partially due to the depletion of endogenous antigens which cause a delayed-type hypersensitivity reaction.

Antigens, CD1↗

PubMed1999

Immunohistochemical study of a patient with diffuse pulmonary corpora amylacea detected by open lung biopsy.

The chest radiographs of an asymptomatic 58-year-old Japanese man with pulmonary corpora amylacea (PCA) revealed bilateral patchy and nodular infiltrates. Lung specimens obtained by open lung biopsy were histochemically and immunohistochemically analyzed. In all sections of dissected lung tissue, hematoxylin and eosin staining revealed homogeneous eosinophilic acellular round bodies (50-100 microm in diameter) containing granular black pigments in the alveolar spaces. Some round bodies were surrounded and phagocytized by alveolar macrophages. The laminated round bodies stained positively with PAS and Congo red. In addition, many of the rounded bodies contained particles which stained positively with Berlin blue. Immunohistochemical staining for epithelial membrane antigen (EMA) as well as PE-10 was distinctively positive. This is a very rare case of diffuse PCA found by open lung biopsy. Immunohistochemical examination suggested that PCA consisted of pulmonary surfactant protein and epithelial membrane antigen.

Biopsy↗

PubMed1999

[A clinicopathologic study of progressive subcortical vascular encephalopathy of the Binswanger type (PSVE)].

From an electron microscopic study I indicated that the number of nerve fibres per unit area in the frontal white matter was significantly less in PSVE than that in controls. The white matter pallor in PSVE is mainly based on the loss of nerve fibres. The dementia in PSVE is probably related to the loss of nerve fibres in the cerebral white matter. The extent of frontal white matter pallor tended to be less broad in vascular parkinsonism (VP) than in PSVE without parkinsonism. The relatively slight damage of the white matter may contribute to VP observed in PSVE. The number of oligodendrocytes and of astrocytes was decreased in PSVE showing half of that in the deep white matter of the controls. This suggests that the loss of oligodendrocytes and astrocytes can play a role to the process of nerve fibres loss in PSVE. Not only the severe hyalinotic changes in the white matter arterioles, but also the diffuse atherosclerotic lesions in the main stem of cerebral arteries were the characteristic arterial lesions in PSVE. On the basis of these arteriosclerotic lesions, we speculated that the repeated hypotension or the greater variability of casual blood pressure could induce PSVE in the elderly hypertensives. However, the retrospective analysis of casual blood pressure did not support our hypothesis.

Brain↗

PubMed1999

[Cortical dysplasia].

Explore the source record for details and available documents.

Cerebral Cortex↗

PubMed1999

[A case report of pure micrographia progressing over 5 years--an early sign of "pure akinesia"?].

We report a 68-year-old man who have had only slowly progressive micrographia in both hands over the past 5 years without rigidity, tremor, bradykinesia, and festination or freezing in walking. The fine finger movements were normal. PET studies suggested the diagnosis of progressive supranuclear palsy or pure akinesia. Administration of L-DOPA and L-threo-DOPS did not improve his micrographia. Festination and freezing in writing may contribute to the genesis of micrographia in this case. We postulate that "pure micrographia" is an early atypical sign of pure akinesia.

Aged↗

PubMed1999

[Orthostatic transient unresponsiveness in an elderly patient with severe cerebral arteriosclerosis under antihypertensive medication].

An 80-year-old man who had was administered antihypertensive medication showed repeated transient unresponsiveness during standing and/or walking. Neurological examination showed no focal neurological signs except mild dementia. Head-up tilting examination induced unresponsiveness and a decrease of systolic blood pressure from 111 mmHg to 86 mmHg. This unresponsiveness disappeared 3 minutes later when the blood pressure recovered to 102/64 mmHg. Cerebral angiography demonstrated occlusion in the right internal carotid artery and the right vertebral artery. Severe stenosis was observed at the left internal carotid artery and the left vertebral artery. Discontinuance of the antihypertensive medication reduced the frequency of orthostatic transient unresponsiveness. Elastic stockings in the lower extremities completely prevented the attack; head-up tilting did not induce hypotension with elastic stockings. The transient unresponsiveness in the present case was probably correlated to hemodynamic failure under the condition of severe cerebral arteriosclerosis.

Aged↗

PubMed1999

[Home hospice care at a clinic].

For the people who want to stay at home until their last day, the primary doctor and clinic where they were diagnosed will be the most reliable supports. We have been operating a 19 bed clinic since 1996. In these three years, we have established what we call a "combination palliative care system." A team composed of two doctors, 13 nurses, 3 care aids, a social worker, and a counselor provides home care services as well as outpatient and inpatient care. From April, 1998 to March, 1999, 59 patients died of cancer. Among them, 25 patients died at home. Their primary cancers were lung (7), colon (3), pancreatic (2), breast (2), ovarian (2), brain (1), stomach (1), hepatoma (1), neck (1) and others. First of all, sufficient consultation with patients and family makes this care successful. Through this, the patient can choose his style of care. The whole staff is involved in this care in turn, so that all of us become acquainted with each patient. Home care includes: 1) medical and nursing service available 24 hours a day, 2) activation of social resources for the support of the patient user, 3) constructive cooperation with relevant institutions, 4) relieving the patient's physical and mental suffering, 5) aroma therapy, oil massage, hair cuts and music therapy, and 6) support by volunteers. In this way, as a neighborhood clinic, the combination palliative care system is valuable.

Female↗

PubMed1999

[Home palliative care of brain tumor patients from our clinic].

This study investigated whether or not home palliative care of brain tumor patients was possible and various ideas for accomplishing this, over the 2 1/2 years since our clinic was opened. There were 22 patients, aged 42-72 years, comprising 7 cases of glioblastoma, 14 cases of metastatic brain tumor, and 1 case of unknown origin. The control of intracranial hypertension and attacks of convulsion was possible with oral medication or suppositories, but not injection. The prognosis of cancer patients which changed home care showed no remarkable changes, and the home care rate was 53%. Malignant brain tumor patients were able to enjoy time with their families at home during the terminal stage, and die with dignity.

Brain Neoplasms↗

PubMed1998

Genomic DNA sequence of a rice gene coding for a pullulanase-type of starch debranching enzyme.

A genomic DNA containing a rice (Oryza sativa L., cv. Norin-8) gene coding for a pullulanase-type starch debranching enzyme (EC 3.2.1. 41) was sequenced (EMBL/GenBank/DDBJ accession number AB012915). Along the 15, 248 bp DNA, the pullulanase gene is split into 26 exons. The four pullulanase consensus regions are positioned in the middle portion of the sequence and are separated by long introns and 1-3 exons. Comparison of the rice cv. Norin-8 pullulanase genomic structure with that of barley pullulanase (limit dextrinase) (F. Lok et al., EMBL/GenBank/DDBJ accession number AF022725) indicates that most of the pullulanase exons are highly conserved. Alignment of the nucleotide bases of rice exon 8 with those of barley exon 8-intron 8-exon 9 fragment suggests that the 85 bp internal sequence of rice exon 8 was originally an intron, a possibility further indicated by the absence in barley and spinach (A. Renz et al., EMBL/GenBank/DDBJ accession number X83969) pullulanases of amino acid residues encoded by the 85 bp fragment.

Base Sequence↗

PubMed1998

Cerebrospinal fluid homovanillic acid levels are not reduced in early corticobasal degeneration.

To investigate the contribution of nigral degeneration to the development of parkinsonism in the early stages of corticobasal degeneration (CBD), we measured the cerebrospinal fluid (CSF) levels of homovanillic acid (HVA) in patients with early CBD (n = 5), and compared the levels with those in patients with early Parkinson's disease (n = 11) and in normal subjects (n = 13). The mean CSF HVA level in the early CBD group (33.1 +/- 6.0 ng/ml) did not differ significantly from that in the control group (37.1 +/- 12.7 ng/ml), whereas that in the early Parkinson's disease group (19.0 +/- 7.6 ng/ml) was reduced significantly (P < 0.001). This result suggests that neuronal cell loss in the substantia nigra and presynaptic nigrostriatal dopaminergic neuron dysfunction are mild in the early stages of CBD.

Aged↗

PubMed1998

Early forms of microtubule-associated protein are strongly expressed in cortical dysplasia.

We report the enhanced expression of early forms of microtubule-associated proteins (MAPs) in cortical dysplasia in surgical resections from 17 children with intractable epilepsy. Large neurons, which represent one of the characteristic cellular features of cortical dysplasia, showed strong immunoreactivity for MAP1B, as well as the low-molecular-weight isoform of MAP2 (MAP2c). In situ hybridization with MAP1B antisense riboprobe showed markedly increased hybridization signal intensities in the large neurons, whereas neurons in the normal-appearing cortex and most of the normal-sized neurons in the dysplastic cortex had faint signals. Because MAP2c and MAP1B are early forms of MAPs, which are abundantly expressed in the developing brain and down-regulated in the adult, and are thought to be involved in neuronal outgrowth and plasticity, our results suggest that the structural remodeling of neuronal processes is activated in cortical dysplasia.

Adolescent↗