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Biomedical subjects

S Shinoda

Publications and source records attributed to S Shinoda.

At least 73 records · Page 4Linked to original sources
PubMed1997

Intracerebral Schwannoma--case report.

A 15-year-old girl presented with a rare intracerebral schwannoma manifesting as epileptic seizure. Computed tomography, magnetic resonance imaging, and cerebral angiography showed a right parietooccipital lobe tumor. The preoperative diagnosis was malignant glioma, but immunohistochemical and ultrastructural examinations showed the tumor was indistinguishable from peripheral schwannoma. Only 29 cases of schwannomas not related to the cranial nerve have been reported, mostly in children and young adults. The origin appears to be ectopic or perivascular elements in the brain. Such intracerebral schwannomas can be classified according to origins into intra-axial, periventricular, dural attachment, and other types.

Adolescent↗
PubMed1996

Elevated expression of DNA polymerase beta gene in glioma cell lines with acquired resistance to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3- nitrosourea.

We investigated the expression of DNA polymerase beta (beta-pol) and O6-methylguanine-DNA methyltransferase (MGMT) in human glioma cells with acquired resistance to 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosoure a (ACNU) and in the parent cells. ACNU-resistant T430 (T430R) and A172 (A172R) glioma cell lines were established following repeated exposure to ACNU. The level of MGMT mRNA expression was elevated in T430R, but not in A172R. In contrast, the level of beta-pol mRNA expression and the level of beta-pol protein were elevated in A172R, compared with the parent cells. While the mechanism of MGMT repair has been considered to be important in the drug resistance of human brain tumors to ACNU, our present results demonstrate that beta-pol may also play an important role in the acquisition of tumor cell resistance to ACNU in human gliomas.

Antineoplastic Agents↗
PubMed1996

Regulation of sulphate assimilation in Saccharomyces cerevisiae.

We examined how the activity of O-acetylserine and O-acetylhomoserine sulphydrylase (OAS/OAH) SHLase of Saccharomyces cerevisiae is affected by sulphur source added to the growth medium and genetic background of the strain. In a wild-type strain, the activity was repressed if methionine, cysteine or glutathione was added to the growth medium. However, in a strain deficient of cystathionine gamma-lyase, cysteine and glutathione were repressive, but methionine was not. In strains deficient of serine O-acetyltransferase (SATase), OAS/OAH SHLase activity was low regardless of sulphur source and was further lowered by cysteine and glutathione, but not by methionine. From these observations, we concluded that S-adenosylmethionine should be excluded from being the effector for regulation of OAS/OAH SHLase. Instead, we suspected that S. cerevisiae would have the same regulatory system as Escherichia coli for sulphate assimilation; i.e. cysteine inhibits SATase to lower the cellular concentration of OAS which is required for induction of the sulphate assimilation enzymes including OAS/OAH SHLase. Subsequently, we obtained data supporting this speculation.

Acetyltransferases↗
PubMed1996

Involvement of vulnibactin and exocellular protease in utilization of transferrin- and lactoferrin-bound iron by Vibrio vulnificus.

In vitro growth experiments were conducted to evaluate the ability of vulnibactin, a siderophore produced by Vibrio vulnificus, to sequester transferrin- or lactoferrin bound iron for growth. Comparative studies with the strain producing vulnibactin and its exocellular protease-deficient mutant revealed the involvement of the protease in addition to vulnibactin in effective utilization of iron ion (Fe3+) bound to transferrin and lactoferrin. It appears that the protease causes cleavage of these proteins, thereby making bound iron more accessible to vulnibactin.

Amides↗
PubMed1996

Expression of virulence-related properties by, and intestinal adhesiveness of, Vibrio mimicus strains isolated from aquatic environments.

A study of the major pathogenic characteristics of Vibrio mimicus was carried out with 77 strains isolated from aquatic environments in Okayama, Japan. Of the strains tested, 96% demonstrated in vitro adherence to the rabbit intestinal mucosa, of which 36, 20, and 43% belonged to the strongly, moderately, and weakly adhesive groups, respectively. Of the 27 strains which appeared to be enterotoxigenic in the experiments using rabbit ileal loops, 74% belonged to the strongly adhesive group. All strains of V. mimicus at early log phase showed cell-mediated hemagglutination, and 70% of strongly hemagglutinative strains belonged to the strongly adhesive group, implying a possible correlation between cell-mediated hemagglutination and bacterial adherence. However, no significant correlation could be detected in the production of putative exocellular pathogenic factors and bacterial adherence or enterotoxigenicity.

Animals↗
PubMed1996

Comparison of a fluorogenic assay with a conventional method for rapid detection of Vibrio parahaemolyticus in seafoods.

A conventional method and a fluorogenic assay for the detection of Vibrio parahaemolyticus were compared. Among 29 seafood samples examined for the presence of V. parahaemolyticus, 17 samples harbored V. parahaemolyticus, and trypsinlike activity was noticed in 19 seafoods. The added fluorogenic substrate was cleaved in single samples of shrimp, turbo, and cuttlefish from which V. parahaemolyticus could not be isolated by the conventional method. Vibrio alginolyticus, in addition to V. parahaemolyticus, was found to exhibit intracellular trypsinlike activity. Trypsinlike activity in seafoods was observed after the most probable number for the initial density of V. parahaemolyticus-like organisms was found to have reached > 10(2) per g. A V. parahaemolyticus inoculum at 10(4) CFU/ml in arabinose-glucuronate medium was required to attain growth to 10(6) CFU/ml, which is the level necessary for the release of detectable amounts of fluorescent compound from the added substrate.

Animals↗
PubMed1996

Purification and characterization of novel hemagglutinins from Vibrio mimicus: a 39-kilodalton major outer membrane protein and lipopolysaccharide.

Two hemagglutinins (HAs) mediating the agglutinability to rabbit erythrocytes were isolated from 32-h culture supernatant of enterotoxigenic strain E-33 of Vibrio mimicus by ultrafiltration followed by gel filtration and anion-exchange column chromatography. The HAs were designated R-HA and C-HA on the basis of specific hemagglutinating activity towards rabbit erythrocytes only (R-HA) and towards chicken and rabbit erythrocytes (C-HA). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subsequent staining with Coomassie brilliant blue revealed no detectable protein band and a single band of Mr 39,000 in the case of R-HA and C-HA, respectively. However, silver staining of the gel containing R-HA revealed the appearance of low-molecular-weight material. These two HAs differed from each other and from previously reported HA/protease in receptor specificity, molecular composition, and biochemical and immunochemical properties. No simple sugar other than glycoproteins, including mucin, inhibited hemagglutinating activities of both C-HA and R-HA. Rabbit antibody against R-HA or C-HA could agglutinate E-33 whole cells, implying a possible cell surface origin of the two HAs. The isolated E-33 lipopolysaccharide (LPS) or its polysaccharide moiety conferred biochemical and immunochemical properties identical to those of R-HA, confirming that the R-HA represents polysaccharide of LPS. The LPS preparations from heterologous strains of Vibrio mimicus and Vibrio cholerae non-O1 confirmed that the hemagglutinating ability is a common function of LPS. On the other hand, the antibody against C-HA specifically recognized a major outer membrane protein (OMP) with an Mr of around 39,000 in both homologous and heterologous strains of V. mimicus, suggesting an OMP origin of C-HA. Furthermore, the antibody recognized a major OMP with an Mr of around 37,000 in V. cholerae. Although the immunogenicity of LPS and OMP is well documented for important intestinal pathogens, the hemagglutinating properties of such attractive cell surface components are hitherto unrecognized and will definitely contribute towards understanding their role in bacterial adherence.

Amino Acids↗
PubMed1996

[A case of alveolar soft-part sarcoma with cerebral metastases].

A case of alveolar soft-part sarcoma with multiple cerebral metastases in addition to multiple lung and bone metastases is reported. This is a rare tumor which thus far has only been recognized as a malignant soft tissue tumor with great uncertainty. A 24-year-old man with a chief complaint of left frontal headache was admitted to our unit on September 26, 1994. A tumor of the right forearm had been surgically removed 9 years previously, and surgery had been followed by two courses of chemotherapy with vincristine, cyclophosphamide and actinomycin-D and subsequent irradiation for bone metastasis. The chemotherapy, however, did not have any clear effect. Neurological examination at the time revealed only bilateral papilledema, but CT and MRI scan of the brain showed a round mass in the left occipital lobe with homogeneous enhancement and another small mass was detected in the right occipital lobe. A cerebral angiogram showed a vascular tumor. The preoperative diagnosis was multiple cerebral metastases of alveolar soft part sarcoma. Left occipital craniotomy was performed on October 12, 1994, and the tumor was completely removed by lobectomy. Specimens of the tumor showed typical histological features of alveolar soft-part sarcoma. Whole-brain radiotherapy was administered postoperatively, and the patient is well neurologically without right homonymous hemianopsia. The clinical features of alveolar soft-part sarcoma are discussed. Only a few cases have been reported in the literature, but the most frequent site of the primary lesion has been the lower extremities, and cerebral metastasis has not been rare. All efforts should be focused on discovering this tumor in the early stage because surgical removal can yield good results, and radiotherapy is thought to be effective in terms of patient "quality of life".

Adult↗
PubMed1996

[Report of a case of intraosseous meningioma: a review of the literature and diagnostic value using MRI study].

A 40-year-old woman with intraosseous meningioma is reported. She was admitted because of a slowly growing, bony hard, fixed mass in the temporal area that was covered by the normal scalp. The neurological examination on admission was negative. Plain skull radiogram demonstrated an area of hyperostotic change in the temporal region. Bone-targeted CT demonstrated irregularity in the structure of the skull bone. Selective external carotid angiogram showed a homogeneous tumor stain in the region of the skull thickening. Macroscopically complete tumor resection (Simpson's grade 1) was carried out. Her postoperative course was uneventful. The skull tumor had the typical feature of meningotheliomatous meningioma. MRI showed a mass lesion of the temporal bone on T1- and T2-weighted images, and a well-enhanced mass lesion of the outer dura and outer table of the skull bone on Gd-DTPA enhanced T1 images. The findings of the preoperative MRI study using Gd-DTPA were identical with the tumor area on histological study. Therefore, MRI with Gd-DTPA enhancement was considered a useful diagnostic modality.

Adult↗
PubMed1995

Utilization of hemin and hemoglobin as iron sources by Vibrio parahaemolyticus and identification of an iron-repressible hemin-binding protein.

Several clinical isolates of Vibrio parahaemolyticus were examined for their ability to utilize either hemin or hemoglobin as a sole source of iron. Both compounds appeared to be equally good iron sources. Maximum growth was obtained at 5 microM hemin or 1.25 microM hemoglobin under the conditions tested. Using a hemin-agarose batch affinity method, the hemin-binding protein was isolated from crude total membranes of a hemin-utilizing strain, WP1, grown under iron-deficient but not under iron-sufficient conditions. This protein was identical to the 83 kDa outer membrane protein which was expressed in response to iron limitation. The protein was susceptible to proteinase K cleavage in whole cells, indicating its exposure at the cell surface. Hemin and hemoglobin, but not protoporphyrin IX, inhibited binding of the protein to hemin-agarose.

Carrier Proteins↗
PubMed1995

Production of antigenically related exocellular elastolytic proteases mediating hemagglutination by vibrios.

Exocellular proteases produced by Vibrio fluvialis, V. furnissii, V. metschnikovii and V. campbellii were characterized and compared to those of V. mimicus protease (VMP) and V. vulnificus protease (VVP). These proteases possessed both elastolytic and hemagglutinating abilities and were identified, except that of V. metschnikovii, as metalloprotease. Conversely, V. metschnikovii protease failed to exhibit some of the salient features for metalloproteases suggesting the existence of protease(s) other than metalloprotease. However, antibodies against VVP cross-reacted to these proteases and to VMP indicating antigenic relatedness amongst vibrio proteases. This study, thus, demonstrated the prevalent distributions of antigenically related proteases both in pathogenic and non-pathogenic vibrios, bringing their status as a virulence determinant into question.

Antigens, Bacterial↗
PubMed1995

Demonstration of a ferric vibrioferrin-binding protein in the outer membrane of Vibrio parahaemolyticus.

Under iron-restricted conditions, Vibrio parahaemolyticus produces a siderophore, vibrioferrin, accompanying expression of two major outer membrane proteins of 78 and 83 kDa. Autoradiographic analysis of nondenaturing polyacrylamide gel electrophoregrams of outer membrane preparations previously incubated with [35Fe]ferric vibrioferrin revealed a single radiolabeled band, in which the 78-kDa protein was detected predominantly by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antiserum against the purified 78-kDa protein partially inhibited Fe-VF binding to isolated OMPs. The 78-kDa protein was cleaved by the treatment of whole cells with proteinase K, indicating that a portion of this protein is exposed on the surface of the outer membrane. The treated cells lost most of their iron uptake activity mediated by vibrioferrin. These results suggest that the ferric vibrioferrin-binding protein of 78 kDa may function as the receptor for ferric vibrioferrin involved in the initial step of vibrioferrin-mediated iron uptake. Immunoblot analysis using the antiserum against the 78-kDa protein demonstrated that the molecular mass and antigenic properties of the protein were highly conserved among V. parahaemolyticus strains examined. The antiserum also recognized an iron-repressible outer membrane protein of 78 kDa from iron-restricted V. alginolyticus strains, some of which appeared to produce vibrioferrin.

Bacterial Outer Membrane Proteins↗
PubMed1995

Actions of Vibrio vulnificus metalloprotease on human plasma proteinase-proteinase inhibitor systems: a comparative study of native protease with its derivative modified by polyethylene glycol.

Vibrio vulnificus, an opportunistic human pathogen causing wound infection and septicemia, produces a metalloprotease (VVP) which is suspected to be a virulent determinant. The interactions of VVP, as well as its derivative (PEG1-VVP) modified with polyethylene glycol, with a variety of human plasma proteins were investigated. We found that native VVP and its derivative were able to act directly on many biologically important human plasma proteins even in the presence of alpha-macroglobulin, the sole plasma inhibitor of native VVP. The activities of both classical and alternative pathways of the complement cascade system were drastically abolished by incubation with either VVP. Furthermore, these proteases rapidly digested the A alpha-chain of human fibrinogen into fragment(s) with no clotting ability. Therefore both VVPs are thought to function as a fibrinogenolytic enzyme, causing delay of the coagulation reaction. VVP and PEG1-VVP were also shown to destroy plasma proteinase inhibitors including alpha 1-proteinase inhibitor, a major inhibitor in human plasma. Because endogenous proteolytic enzymes and their inhibitors are indispensable in maintaining physiological homeostasis, these findings suggest that VVP (and PEG1-VVP) may cause an imbalance of human plasma proteinase-proteinase inhibitor systems, thus eliciting an immunocompromised state in the host and facilitating the development of a systemic V. vulnificus infection such as septicemia.

Amino Acid Sequence↗
PubMed1995

Frequent loss of the cyclin-dependent kinase-4 inhibitor gene in human gliomas.

Studies have shown that homozygous deletion of the cyclin-dependent kinase-4 inhibitor (CDK4I) gene, which is mapped to chromosome 9p21, is frequently observed in various types of human cancers. Here we report that the CDK4I gene was deleted in gliomas. Eight cell lines derived from glioblastomas and samples from 14 patients with various grades of gliomas were examined by Southern blot analysis. We found that the CDK4I gene was deleted in 7 of 8 (87.5%) cell lines and 7 of 9 (78%) samples from high-grade glioma patients, whereas it was deleted in 1 of 5 (20%) low-grade glioma samples. These results suggested that inactivation of the CDK4I gene may play an important role in the progression of human glioma.

Adolescent↗
PubMed1995

Genetic analysis of IgE and the IGHE, IGHEP1 and IGHEP2 genes in atopic families.

The familial occurrence of allergic diseases was studied in 478 individuals and their family members. The results showed that there was pronounced familial clustering. Total serum IgE concentrations of atopic patients and their parents were well correlated. Moreover, the concentration of specific IgE of the patients and their parents was also well correlated, suggesting that IgE production was genetically determined. To determine if major structural abnormalities of IGHE, IGHEP1 and IGHEP2 genes might lead to aberrant control and subsequent increase in IgE concentration, genomic DNAs from 55 individuals, i.e., 31 atopic patients and their family members, were examined. We detected the IGHE, IGHEP1 and IGHEP2 genes in all 55 leukocyte DNAs. We could not find any large deletions or duplications in the IGHE, IGHEP1 and IGHEP2 genes of atopic patients with high serum IgE concentrations.

Adolescent↗
PubMed1995

[A case of painful tic convulsif due to cerebellopontine angle epidermoid tumor which could not be clearly detected by MRI].

A case of painful tic convulsif (trigeminal neuralgia and ipsilateral hemifacial spasm) caused by cerebellopontine angle epidermoid tumor is presented. This tumor was compressed to the trigeminal nerve, and became attached to the facial and auditory nerves. The facial nerve exit-zone of brain stem was also compressed by the tumor along with a branch of the posterior inferior cerebellar artery. Total removal of the tumor was carried out and neuralgia and facial spasm disappeared. Painful tic convulsif caused by brain tumor is rare (eight cases in the literature plus our case), but epidermoid tumor is not rare as a cause of this complaint (seven in eight cases). In preoperative examination of this case, we could not detect this epidermoid in the cerebellopontine angle, because this tumor was the same intensity as CSF liquid on magnetic resonance imaging (T1 and T2 weighted image) and exerting hardly any mass effect on the brainstem. On encountering a case of painful tic convulsif of unknown origin despite the usual preoperative examinations, it may be useful that same kind of brain tumor, especially, epidermoid might be concealed in the cerebellopontine angle lesion.

Adult↗
PubMed1995

Expression of surrogate light chain in common variable immunodeficiency.

VpreB and lambda-like genes encode proteins that can associate to form a light-chain-like structure, the surrogate light chain (SLC). VpreB and lambda-like genes are selectively expressed in human progenitor B and precursor B (pre-B) cells. We analyzed the expression of VpreB and lambda-like genes in seven patients with common variable immunodeficiency (CVI). Gene expression was examined in the peripheral blood mononuclear cells (PBMCs) using the polymerase chain reaction. In four CVI patients, two of whom were brothers, the expression of the VpreB gene was detectable in the PBMCs. In the brothers with CVI, the expression of the VpreB gene was also examined in bone marrow cells, where it was found to be expressed in trace amounts. A number of the brothers' bone marrow cells were stained with mu and kappa antibodies using the avidin-biotin complex method. In lambda 5-gene-deleted mice, B cell development in the bone marrow is blocked at the pre-B stage, but the blockade is leaky. We suggest that expression of the SLC is weak in patients with CVI compared with their normal counterparts, and this may be one of the underlying mechanisms of CVI.

Adult↗