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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 253 records · Page 14Linked to original sources
PubMed1997

Pathologic significance of meningeal enhancement ("flare sign") of meningiomas on MRI.

BACKGROUND: The purpose of this study was to clarify the pathologic features and clinical significance of the meningeal enhancement surrounding meningiomas ("flare sign") on contrast-enhanced T1-weighted magnetic resonance images (MRI). METHODS: The marginal dura mater of tumors was resected from nine cases of meningioma exhibiting a flare sign and used for histopathologic evaluation. RESULTS: Connective tissue proliferation was found in the dura mater in all cases, vascular proliferation was found in three, and tumor cell nests were observed in four cases. In one case, tumor cells were found 4.5 mm from the edge of the tumor. In another case, a meningothelial cell cluster was found. CONCLUSIONS: These results suggest that tumor cell nests are present frequently in dura mater that exhibits the flare sign, and that the dura mater near these lesions should be resected as widely as possible.

Aged↗
PubMed1997

Long-term survival of 'damaged' Nippostrongylus brasiliensis adult worms in the testosterone-treated Indian soft-furred rat, Millardia meltada.

When testosterone-treated female Millardia meltada were infected with Nippostrongylus brasiliensis, adult worms persisted for over seven weeks. The kinetics of faecal egg counts showed a biphasic pattern having a transient decline at around two weeks post infection (p.i.). Thus the status of N. brasiliensis adult worms surviving in the small intestines of testosterone-treated M. meltada was examined. The fecundity and maturity of eggs in the uteri of female adult worms were examined at one, two, three and seven weeks p.i. Both the fecundity and maturity of eggs transiently decreased at two and three weeks p.i. and then completely recovered by seven weeks. Adoptive transfer of N. brasiliensis adult worms into naive recipients can discriminate the status of worms. Those obtained from the stable phase of a primary infection ('normal' worm) can establish and survive in the recipients, whereas those obtained at the time of expulsion ('damaged' worm) are rapidly expelled. Therefore, 300 each of N. brasiliensis adult worms collected from the testosterone-treated female M. meltada at one, two and seven weeks p.i. were transferred intraduodenally into normal rats to determine their status. Those collected at one week p.i. persisted for eight days, indicating that they were still 'normal'. In contrast, worms collected at two and seven weeks p.i. were expelled within four days, indicating that they had already been 'damaged'. Moreover, when the 'damaged' worms obtained from rats were intraduodenally transferred into testosterone-treated female M. meltada, they were not expelled, suggesting that testosterone-treatment affected the final expulsive step, but not the damaging process, of the mucosal defence of M. meltada against N. brasiliensis adult worms.

Animals↗
PubMed1997

Induced pupillary hippus following near vision: increased occurrence in visual display unit workers.

Using a quasistatic method, it has been found previously that one-third of normal subjects retained pupillary constriction under empty-field conditions for a substantial period following a near-vision task. This pupil after-effect was dissociated from adaptation of tonic accommodation. In this paper, essentially the same method was used to investigate further the effects of near vision on pupil response in VDU (Visual Display Unit) workers with complaint of general fatigue and/or asthenopia. In some cases, large and slow pupillary oscillation accompanied by miosis was noted after near vision. Pupillary oscillation is a well-established phenomenon that has a broadly spread frequency spectrum with an occasional component 'hippus' at approximately 0.2 Hz. A proportion of subjects (30 out of 100) showed hippus, a consistent oscillation of 0.22 Hz (SD = 0.03 Hz) in VDU workers, while only one out of 24 normal subjects showed this. Occurrence of pupillary hippus following near vision increased in VDU workers. It was suggested that this hippus is concerned with cumulative asthenopia and/or general fatigue although the origin of hippus is still unknown.

Accommodation, Ocular↗
PubMed1997

Balanced translocation 46,XY,t(2;15)(q37.2;q11.2) associated with atypical Prader-Willi syndrome.

The lack of normally active paternal genes in 15q11-q13, as an outcome of either a paternal deletion or maternal disomy, accounts for >95% of all patients with Prader-Willi syndrome. Other mechanisms, including imprinting mutations and unbalanced translocations involving pat 15q11-q13, have been described elsewhere. In this study, we present a patient with a rare balanced, de novo translocation-46,XY,t(2;15)(q37.2;q11.2)-involving breakage within the Prader-Willi/Angelman syndrome region of the paternal homologue, without an apparent deletion. The patient demonstrated several manifestations of the Prader-Willi syndrome but was clinically atypical. Cytogenetic and molecular studies of this case demonstrated the translocation breakpoint to be between SNRPN and IPW, with mRNA expression of SNRPN and PAR-5 but absence of IPW and PAR-1 expression. These results suggest that disruption of either IPW expression or a nearby gene by an upstream break may contribute to the Prader-Willi syndrome phenotype and that expression of SNRPN or other upstream genes is responsible for other aspects of the classical Prader-Willi syndrome phenotype.

Animals↗
PubMed1997

Malignant glomus tumor: a case report and review of the literature.

This report concerns a malignant glomus tumor, a rare soft tissue tumor that was examined immunohistochemically and ultrastructurally. It occurred in a 44-year-old male patient who had suffered from dull pain and stiffness in the right thigh for 10 months. Radiographic examination revealed a well-defined osteolytic lesion in the diaphysis of the right femur. Hypervascularity of the tumor was observed angiographically. Computed tomographic and magnetic resonance examinations showed an intramuscular mass invading the marrow space of the femur. Wide resection was performed after open biopsy. Histologically, round to polygonal tumor cells revealed a uniform appearance of round to ovoid nuclei with single large nucleoli and slightly eosinophilic cytoplasm, forming solid sheets of cells interrupted by vessels of varying size. A few mitotic figures and vascular invasion were observed. Immunohistochemically, vimentin and alpha-smooth muscle actin were stained intensely, and muscle actin was positive for tumor cells of the perivascular area. Tumor cells were negative for desmin, factor VIII-related antigen, S-100 protein, neurofilament, cytokeratin, and epithelial membrane antigen. Ultrastructurally, tumor cells were characterized by many cytoplasmic processes, pinocytotic vesicles, plasmalemmal dense plaques, and scattered microfilaments in the cytoplasm. Few cell junctions and focal basement membrane-like structures were observed. No recurrence or metastasis was noted 57 months after operation. This case was considered to be a malignant glomus tumor, that is, a glomangiosarcoma arising de novo.

Actins↗
PubMed1997

Cloning and expression of an intracellular alkaline protease gene from alkalophilic Thermoactinomyces sp. HS682.

An intracellular alkaline serine protease gene of alkalophilic Thermoactinomyces sp. HS682 was cloned and expressed in Escherichia coli. Sequence analysis showed a putative promoter region, a putative transcriptional termination signal, and an open reading frame of 963 bases, coding for a polypeptide of 321 amino acids. The protease expressed in E. coli was purified by DEAE-Toyopearl 650M and Sephadex G-75 chromatography. The N-terminal sequence (30 amino acids) of the purified protein was coincident with Asp16-Val45 of the deduced amino acid sequence of the ORF. Fifteen amino acids in the N-terminal region were removed during the purification procedures. The deduced amino acid sequence showed high similarity with microbial intracellular serine proteases. The molecular mass of this enzyme was estimated to be 38 kDa by SDS-PAGE. The enzyme was stable at pH 6.0-12.0 and below 60 degrees C in the presence of Ca2+. The temperature and pH optima of the enzyme were 65 degrees C and pH 11.0, respectively. The enzyme was inhibited by DFP and PMSF, but not by MIA and EDTA.

Amino Acid Sequence↗
PubMed1997

Sensitive enzyme-linked immunosorbent assay (ELISA) to measure parasite-specific antibodies of Indian soft-furred rats, Millardia meltada.

Immunoglobulin G (IgG) of Indian soft-furred rat, Millardia meltada, was purified by an immunoaffinity chromatography and antibodies against it was raised in rabbit. Using this rabbit anti-M. meltada IgG antibody, sensitivity of enzyme-linked immunosorbent assay (ELISA) to measure parasite-specific antibodies in the sera of M. meltada was markedly enhanced than the previous method using rabbit anti-mouse IgG and rabbit anti-rat IgG antibodies, which could cross-react to M. meltada IgG. Since M. meltada could effectively produce circulating antibodies against two intestinal helminths, Strongyloides venezuelensis and Nippostrongylus brasiliensis, the high susceptibility of this animal to an array of parasites seems to be not due to general immunological deficiency.

Animals↗
PubMed1997

Phylogenetic position and geographic differentiation of the Japanese dormouse, Glirulus japonicus, revealed by variations among rDNA, mtDNA and the Sry gene.

The Japanese dormouse, Glirulus Japonicus, is the only extant lineage that represents this genus and it has been classified as a single species distributed on the three main islands of Japan, namely Honshu, Shikoku and Kyushu. However, individuals collected from Fukui, Wakayama and Kochi Prefectures (southwestern part of Japan) yielded distinctly different profiles of restriction fragments of the nuclear ribosomal DNA (rDNA) spacer from those collected from Yamanashi and Nagano Prefectures (central Japan). The estimated sequence divergence between the two groups was 2.8% on average, which corresponds to a putative divergence some two million years ago. Representing mitochondrial DNA (mtDNA) sequences, 402 bases of cytochrome b gene were determined by direct sequencing and the estimated extent of the sequence divergence between the two groups was 6.5-7%. Differences between the two geographic groups were also substantial in the sequences of about 300 base-fragments from the Y-linked, sex-determining locus, Sry. To assess the phylogenetic relationships between the Japanese dormouse and members of the family Myoxidae, we compared sequences of mitochondrial 12S rRNA gene of Japanese dormice with those of the forest dormouse (Dryomys nitedula) and the common dormouse (Muscardinus avellanarins), two continental genera thought to be closely related to the genus Glirulus. The results showed that the sequences from Japanese dormice were distinct from any sequences of the two continental species and the extent of the differences were somewhat similar to that between the rat (Rattus norvegicus) and the hamster (mesocricetus auratus).

Animals↗
PubMed1997

An analysis of users' preference on keyboards through ergonomic comparison among four keyboards.

The usability of four kinds of keyboards as regards touch and feel was evaluated by measuring the performance and eliciting the preferences of a total of 24 Japanese participants in a test that consisted of typing English text. It was found that quiet keyboards with an indistinct tactile feedback tend to give higher uncorrected error rates than keyboards with a distinct tactile feedback and clicking sound, while no significant difference in throughput was found among the four keyboards. As regards preference, the test participants were divided into two groups: those who preferred keyboards with a distinct tactile feedback and clicking sound, and those who preferred keyboards with an indistinct tactile feedback and no sound. Analysis revealed that these two groups also showed different sensations and preferences with respect to several aspects of the touch and feel of keyboards. This result suggests that suppliers of computer keyboards should provide two kinds of keyboards, with distinct and indistinct tactile key switches, in order to satisfy as many users as possible.

Computer Peripherals↗
PubMed1997

[An autopsy case of corticobasal degeneration mimicking frontal Pick's disease].

A pathologically proven case of corticobasal degeneration (CBD) with marked psychiatric symptoms was reported. A 59-year-old female was admitted to our hospital in October 1989 because of her "forgetfulness". Her abnormal behavior began in August 1989, and she had no psychiatric signs before that time. On this admission she was diagnosed to have panhypopituitarism due to Sheehan syndrome. Cortisone and levothyroxine were administered, but her mental symptoms deteriorated. Strange behaviors such as buying same materials every day and wandering around all day long fully dressed with all of her jewels were observed. She could not perform her housework after March 1991. She was in a bed ridden state after 1992 and died in March 1993, at the age of 62. The total duration of her illness was 3 years and 7 months. Her clinical course resembled frontal Pick's disease. At autopsy advanced gastric cancer without metastasis and infarct of the pituitary gland were found. The weight of the brain was 987g and atrophy of the bilateral frontal lobes was evident on macroscopical examination. Neuronal loss, proliferation of the glia, and spongy state were observed in the superficial layer of the frontal cerebral cortex. Widespread appearance of ballooned neurones was also observed in the deep layers of the frontal cerebral cortex. Neuronal loss and gliosis were found in the striatum, pallidum, thalamus, and substantia nigra. There was neither senile plaques nor Pick bodies. Numerous argyrophilic threads were found by Gallyas-Braak method and all these pathological findings were compatible with the previously reported cases of CBD. Although CBD is considered as predominantly a motor disorder, there are a few reports of pathologically proven cases of CBD mimicking Pick's disease. These cases suggest clinical diversity of CBD and further investigations are essential to establish the disease entity of CBD and Pick's disease.

Basal Ganglia Diseases↗
PubMed1997

[Reliability of Amplicor Mycobacteria test for detection of Mycobacterium tuberculosis complex. M. avium and M. intracellulare: a cooperative study among 9 laboratories].

The Amplicor Mycobacteria, a PCR-based assay, is a rapid test for the detection of Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium intracellulare in clinical samples. To estimate the reliability and reproducibility of the method, a cooperative blind study was conducted among 9 laboratories. Materials used for testing consisted of 105 sputum and 30 water samples containing known numbers of M. bovis BCG, M. avium, M. intracellulare, and samples without bacteria. Only 2 out of the 9 laboratories correctly identified the presence or absence of mycobacterial DNA in all 135 samples. In sputum samples, 6 out of the 9 laboratories detected mycobacterial DNA in all positive samples, and 4 out of the 9 laboratories correctly reported the absence of DNA in the negative samples, indicating the need for good laboratory practice and development of reference reagents to monitor the performance of the whole study, including pretreatment of clinical samples. The main problem was lack of specificity rather than lack of sensitivity. From about half of the laboratories, false-positive results were reported, however, the ratio was below 6%; 1% (1/106 sputum samples) in 3 laboratories, 1.9% (2/105) in 2 laboratories, and 5.7% (6/105) in one laboratory, respectively. These results indicate that the Amplicor Mycobacteria is quite useful for a rapid diagnosis of tuberculosis.

DNA, Bacterial↗
PubMed1997

Fast fluid-attenuated inversion-recovery MR of intracranial infections.

PURPOSE: To assess the usefulness of fast fluid-attenuated inversion-recovery (FLAIR) MR sequences in the diagnosis of intracranial infectious diseases. METHODS: We compared fast FLAIR images with conventional spin-echo images (T1- and T2-weighted) obtained in 20 patients with infectious diseases (six with encephalitis, five with brain abscesses, three with meningitis, two with meningoencephalitis, two with Creutzfeldt-Jakob disease, one with epidural empyema, and one with cysticercosis). Two neuroradiologists independently reviewed the FLAIR images and compared them with the conventional spin-echo images, obtaining agreement in all patients. RESULTS: FLAIR images of diagnostic quality were obtained in 18 patients. In two patients, FLAIR images were degraded by motion. Lesions in the patients with encephalitis and meningoencephalitis were better delineated on FLAIR images than on spin-echo images. FLAIR images clearly depicted lesions in the basal ganglia in both patients with Creutzfeldt-Jakob disease. In patients with brain abscess, meningitis, cysticercosis, and epidural empyema, FLAIR images provided no more information than conventional spin-echo images, and the lesions were seen better on postcontrast T1-weighted spin-echo images. CONCLUSION: Fast FLAIR images showed pathologic changes in intracranial infectious diseases better than or as well as conventional T2- and proton density-weighted spin-echo sequences. However, postcontrast T1-weighted spin-echo sequences resulted in better visibility of abscess, meningitis, cysticercosis, and epidural empyema than did FLAIR images.

Adolescent↗
PubMed1997

[Effects of topical application of adrenergic agents on refraction and accommodation].

In an attempt to clarify the functional role of adrenergic receptors on accommodation, effects of various adrenergic agents on the state of accommodation were studied. Fifty-two emmetropic normal subjects (age: 19-28 y) participated in this study. We examined the effect of the alpha agonist phenylephrine hydrochloride (5%), the alpha 1 antagonist adrenergic bunazosin hydrochloride (0.1%), the beta antagonist timolol maleate (0.5%), the beta 2 antagonist betaxolal hydrochloride (0.5%), and the beta agonist isoproterenol hydrochloride (3%). Using an infrared optometer, the refraction, far point and near point of accommodation, resting point of accommodation (empty-field accommodation and dark focus of accommodation), and accommodative adaptation were measured before and after topical application of various adrenergic agents. Application of bunazosin slightly but significantly decreased the near point of accommodation. Isoproterenol evoked a hyperopic shift on the far point of accommodation. None of the agents had any effect on the resting point of accommodation. Accommodative adaptation was increased by timolol and betaxolol, and decreased by isoproterenol. We surmised that beta adrenergic agents exerted an indirect influence on the parasympathetic nervous system. The activation of beta receptors produced a hyperopic shift on the far point of accommodation and decreased accommodative adaptation, which suggests that activation of adrenergic receptors may reduce parasympathetic activity, hence affecting the state of accommodation.

Accommodation, Ocular↗
PubMed1997

[An autopsy case of multiple myeloma with pineal body and spinal cord dura mater infiltration].

An autopsy case of multiple myeloma (IgD lambda type) with pineal body and spinal cord dura mater infiltration is reported. The 63-year-old man was diagnosed as multiple myeloma (IgD lambda type). He was treated with melphalan and prednisolone. Extra bone marrow masses developed 1 year after the onset. He died with renal failure. At autopsy there were many extra bone marrow masses including pineal body and dura mater of the thoracic cord. Microscopic examination revealed that those mass lesions consisted of neoplastic plasma cells. Myeloma cells also infiltrated perivascular space near the pineal body, subdural space of the cerebrum and brain stem. The cells were labeled VS 38 c immunohistochemically. We discussed routes of the metastasis to the central nervous system of the multiple myeloma. This case suggests that the way of myeloma cells infiltration to the pineal body is hematogenous metastasis, because pineal body have no blood brain barrier.

Dura Mater↗