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Biomedical subjects

S Shinoda

Publications and source records attributed to S Shinoda.

At least 109 records · Page 6Linked to original sources
PubMed1993

Chemical modification of Vibrio vulnificus metalloprotease with activated polyethylene glycol.

Vibrio vulnificus, an opportunistic human pathogen causing septicemia, produces a metalloprotease which is suspected to be a virulence determinant, but which is labile in vivo due to inactivation by alpha-macroglobulin. To obtain a derivative which is stable in vivo, the metalloprotease was modified with activated monomethoxy polyethylene glycol. The modified protease retained full activity to a peptide substrate and 10-20% activity to protein substrates, and was resistant to entrapment by alpha-macroglobulin because of the increased molecular size (approx. 90 kDa). These findings suggest that the modified protease is stable in vivo and may be used to investigate the pathological actions of the protease in the bloodstream.

Bacteremia↗
PubMed1993

Cystathionine gamma-lyase of Saccharomyces cerevisiae: structural gene and cystathionine gamma-synthase activity.

Purification of Saccharomyces cerevisiae cystathionine gamma-lyase (gamma-CTLase) was hampered by the presence of a protein migrating very close to it in various types of column chromatography. The enzyme and the contaminant were nevertheless separated by polyacrylamide gel electrophoresis. N-terminal amino acid sequence analysis indicated that they are coded for by CYS3 (CYI1) and MET17 (MET25), respectively, leading to the conclusion that CYS3 is the structural gene for gamma-CTLase and that the contaminant is O-acetylserine/O-acetylhomoserine sulfhydrylase (OAS/OAH SHLase). Based on these findings, we purified gamma-CTLase by the following strategy: (1) extraction of OAS/OAH SHLase from a CYS3-disrupted strain; (2) preparation of antiserum against it; (3) identification of a strain devoid of the OAS/OAH SHLase protein using this antiserum; and (4) extraction of gamma-CTLase from this strain. Purified gamma-CTLase had cystathionine gamma-synthase (gamma-CTSase) activity if O-succinylhomoserine, but not O-acetylhomoserine, was used as substrate. From this notion we discuss the evolutional relationship between S. cerevisiae gamma-CTLase and Escherichia coli gamma-CTSase.

Amino Acid Sequence↗
PubMed1993

Magnetic resonance imaging of ganglion cell tumours.

The MRI and CT studies of four patients with ganglion cell tumours, one with a cerebellar gangliocytoma (Lhermitte-Duclos disease), and three with gangliogliomas are reported. MRI in Lhermitte-Duclos disease clearly demonstrated a mass of low signal intensity in the left cerebellum on T1-weighted spin-echo (SE) images and an area of high signal intensity with a blurred margin on T2-weighted SE images. These MRI studies were useful for delineating the lesion, which was verified at surgery. In the ganglioglioma, MRI demonstrated two isointense solid masses on T1-weighted SE images, which enhanced clearly with Gd-DTPA. The enhancement study was advantageous in planning surgery.

Adolescent↗
PubMed1993

The role of T lymphocytes in patients with food-sensitive atopic dermatitis.

The role of T lymphocytes was assessed in patients with food-sensitive atopic dermatitis (AD). T lymphocytes plus monocytes responded well to ovalbumin or bovine serum albumin (BSA) in children with AD who were sensitive to hen's egg or cow's milk compared with healthy children and children with immediate allergic symptoms who are sensitive to hen's egg or cow's milk. The responding cells were shown to be predominantly CD4+ T lymphocytes. Interleukin-2 activity and interferon-gamma concentrations in culture supernatants of ovalbumin-stimulated peripheral blood mononuclear cells (PBMCs) from patients with AD who were sensitive to hen's egg were significantly higher than those of healthy children and patients sensitive to hen's egg with immediate symptoms. Expression of Fc epsilon R II on B lymphocytes in cultures of ovalbumin-stimulated PBMCs from patients with AD was significantly higher than that of healthy children, but it tended to be lower than that of patients with immediate symptoms. These results suggest that, in patients with AD who are food sensitive, CD4+ T lymphocytes stimulated by food antigens secrete lymphokines such as interleukin-2 and interferon-gamma that are secreted from TH1 clones in mice, and express Fc epsilon R II on B lymphocyte that is induced by interleukin-4 secreted from TH2 clones in mice. Taken together, cell-mediated immunity may also occur in addition to IgE-mediated hypersensitivity in patients with food-sensitive AD.

Antigens↗
PubMed1993

Effect of elimination diets on food-specific IgE antibodies and lymphocyte proliferative responses to food antigens in atopic dermatitis patients exhibiting sensitivity to food allergens.

Peripheral blood mononuclear cells (PBMCs) from patients with atopic dermatitis (AD) selected as being sensitive to hen's egg or cow's milk responded to food antigens, ovalbumin, or bovine serum albumin, with significantly enhanced DNA synthesis compared with the DNA synthesis in PBMCs from nonatopic control subjects and food-sensitive patients with immediate symptoms. Patients were treated with elimination diets. Symptoms of AD had been in remission during elimination diets. The levels of specific IgE antibodies to hen's egg or cow's milk decreased during elimination diets in patients with positive radioallergosorbent test (RAST). In patients with negative RAST, specific IgE antibodies remained negative during elimination diets. The proliferative responses of PBMCs to food antigens also decreased during elimination diets in patients with proliferative responses before elimination diets. Taken together, specific IgE antibodies to food antigens are useful indexes of the effect of elimination diets in food-sensitive patients with AD and positive RAST, and proliferative responses of PBMCs to food antigens are useful indexes of the effect of elimination diets in food-sensitive patients with AD and proliferative responses of PBMCs.

Adolescent↗
PubMed1993

Structures of two polyamine-containing catecholate siderophores from Vibrio fluvialis.

From low-iron cultures of Vibrio fluvialis AQ 0012, two new compounds with siderophore activity were purified by XAD-7 adsorption followed by preparative TLC. Norspermidine and 2,3-dihydroxybenzoic acid were identified as constituents common to both compounds by GC-MS analyses of their acid hydrolytic products. In addition, L-threonine was identified in the hydrolysate of one compound, named fluvibactin. Based on high magnetic NMR analyses, the structure of fluvibactin was established as N4-[2-(2,3-dihydroxy-phenyl)-trans-5-methyl-2-oxazoline-4-yl]carboxy-N1, N7- bis-(2,3-dihydroxybenzoyl)-norspermidine, and that of the other compound as N1,N7-bis-(2,3-dihydroxybenzoyl)-norspermidine. The structures were supported by fast atom bombardment mass spectrometry. Both of the purified compounds restored growth inhibition of the producer strain and V. cholerae Non-O1 induced by ethylenediamine di-(o-hydroxyphenylacetic acid), a potent synthetic chelating agent of ferric iron.

Catechols↗
PubMed1993

Simple purification method for a Vibrio vulnificus hemolysin by a hydrophobic column chromatography in the presence of a detergent.

A Vibrio vulnificus hemolysin (VVH) was purified by two steps of hydrophobic column chromatography on Phenyl-Sepharose HP. The first chromatography was carried out at pH 6.0. In this pH condition, VVH efficiently bound to the column, but the hemolysin fraction eluted was accompanied with colored substance(s). To eliminate this colored substance, the second chromatography was carried out at pH 9.8 in the presence of 1% 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS), a zwitterionic detergent. Homogeneity of the hemolysin thus obtained was shown by polyacrylamide gel electrophoresis. The specific activity increased 33,600 times and the yield was 35%. The method is simple and useful to supply enough VVH for study of the role of the hemolysin in the infection by V. vulnificus or on the mechanism of action of the hemolysin.

Chromatography↗
PubMed1993

Studies on hemolytic action of a hemolysin produced by Vibrio mimicus.

Some properties and mechanism of action of a hemolysin (VMH) produced by an enteropathogenic Vibrio mimicus strain was examined. VMH was heat-labile and inhibited by addition of divalent cations, including Ca2+, Mg2+ and Mn2+. The hemolysis by VMH was inhibited by incubating with gangliosides, suggesting that the ganglioside was the binding site on the erythrocyte membrane for VMH. Existence of a galactose moiety on reducing end of the ganglioside molecule and a sialic acid on the galactose moiety was suggested to be important for the binding of VMH molecule. Colloid osmotic manner of the hemolysis by VMH was demonstrated.

Animals↗
PubMed1993

Suppressive effects of elimination diets on T cell responses to ovalbumin in hen's egg-sensitive atopic dermatitis patients.

We investigated the effect of elimination diets on T cell responses to ovalbumin (OA) in hen's egg-sensitive atopic dermatitis (AD) patients. The proliferative responses of both peripheral blood mononuclear cells (PBMCs) and T cells with monocytes to OA decreased after elimination diets, but those to Candida albicans or phytohemagglutinin (PHA) did not decrease after elimination diets. The proliferative responses of CD4+ T cells with monocytes to OA decreased after elimination diets. In these patients, clinical symptoms of AD improved. These results indicate that T cells, especially CD4+ T cells, respond to food antigens in food-specific lymphocyte responses, and that elimination diets may be able to initiate reduction of the responsiveness of food-sensitive T cells, especially CD4+ T cells. Moreover, the surface marker phenotypes of the T cells responding to OA were analysed. Our results showed that CD4+CD45RA+ T cells tended to increase. The increase in circulating CD4+CD45RA+ T cells might function as systemic suppression against immune responses in the skin.

Adolescent↗
PubMed1993

Improvement of food-sensitive atopic dermatitis accompanied by reduced lymphocyte responses to food antigen following natural measles virus infection.

Five patients with atopic dermatitis (AD) who were sensitive to hen's egg were observed before and after natural measles virus infection. Within 4 weeks of natural measles virus infection, the eczematous lesions clearly improved in four of the five patients in whom neither offending foods were eliminated, nor anti-allergic drugs, systemic steroids and steroid ointment administered. This was accompanied by reduced proliferative responses of peripheral blood mononuclear cells (PBMCs) to ovalbumin (OA). Another patient showed a transient improvement of AD symptoms, from severe to mild, and thereafter returned to severe accompanied by increased proliferative responses of PBMCs to OA. Radioallergosorbent test (RAST) scores for hen's egg in all five patients did not change in each level in each patient, except the transiently decreased RAST scores for hen's egg in one patient, after the infection. Thus, in patients with AD who are sensitive to food, the improvement of AD symptoms that appeared within 4 weeks of natural measles virus infection was related to reduced proliferative responses of PBMCs to the food antigen following the infection.

Antigens↗
PubMed1993

[A case of arteriovenous malformation with cyst formation].

A case of arteriovenous malformation (AVM) with cyst formation is reported. A 14-year-old girl was admitted to our hospital, complaining of headache. On admission, CT scan showed a cystic mass with mural nodule in the right parietal lobe. Contrast enhanced CT scan demonstrated homogeneous enhancement of the nodule. MRI demonstrated the nodule as an area of signal void. Right carotid angiogram showed a typical nidus with feeding artery and draining vein. The nidus was totally removed by the trans-cystic approach. Histological diagnosis was typical AVM with hemosiderin deposits. AVM with cyst formation is very rare, with only six cases having been reported. The mechanism of cyst formation is controversial. Past reports have hypothesized the participation of a massive hemorrhage, or exudative process. Our case showed hemosiderin deposits, but no symptom indicative of hemorrhage. In this case, the etiology of cyst formation was considered to be exudation and thrombosis of the nidus.

Adolescent↗
PubMed1993

[Evaluation of the postoperative regrowth of the acoustic neurinomas].

Although recent advances in microsurgical removal of acoustic neurinomas has made it possible to preserve, morphologically, the cochlear nerve as well as the facial nerve, functional impairment of the facial nerve is often encountered following total removal of the tumor. In order to avoid such functional morbidity, a surgical procedure can be proposed in which the tumoral capsule attached to a functional structure such as the facial nerve is intentionally left. Along with this surgical procedure and postoperative course observation, postoperative regrowth of the tumor should be precisely evaluated. A few recent reports about this problem have been published since CT scan and MRI have become available. The authors reviewed 66 cases in which postoperative evaluation by high resolution CT scan of the acoustic neurinomas has been carried out in their department more than one year after surgery. Multiple factors such as age at onset, sex, preoperative period, tumor size, vascularity, extent of the tumor removal, residual site, and pathological findings on HE stain were studied in relation to the tumor regrowth. Four cases showed regrowth of the tumor, and one of these tumors was reoperated on. The percentage of regrowth was 7.5% among the tumors which were not totally removed. No significant risk factors for tumor regrowth were noticed in these cases, but tumor regrowth tended to be found in younger patients. The residual tumors which showed regrowth were always located in the internal auditory meatus. In this study, it is apparent that, percentagewise, tumor regrowth is not so prevalent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Activation mechanism of human Hageman factor-plasma kallikrein-kinin system by Vibrio vulnificus metalloprotease.

Vivrio vulnificus, an opportunistic human pathogen, secretes a metalloprotease (VVP). The VVP inoculated into a guinea pig is known to generate bradykinin through activation of the Hageman factor-plasma kallikrein-kinin system. VVP was shown to possess the ability to activate the human system through the same mechanism as that clarified in the guinea pig system, namely, VVP converted both human zymogens (Hageman factor and plasma prekallikrein) to active enzymes (activated Hageman factor and plasma kallikrein), and the then generated kallikrein liberated bradykinin from high-molecular-weight kininogen. However, in the presence of plasma alpha 2-macroglobulin (alpha 2M), the VVP action was drastically decreased. This finding suggests that the human system might be activated only at the interstitial-tissue space which contains negligible amounts of alpha 2M or in the bloodstream of the individuals whose plasma alpha 2M level is extremely reduced.

Bacterial Proteins↗
PubMed1992

Isolation and partial characterization of a compound with siderophore activity from Vibrio parahaemolyticus.

A compound with siderophore activity was purified by successive column and thin layer chromatographic procedures from Dowex 1 x 8 extracts of culture supernatants of Vibrio parahaemolyticus AQ 3354. The strain synthesized the compound in culture media containing less than 2 microM added FeCl3. Hydrolysis of the compound yielded alanine, ethanolamine, citric acid and 2-ketoglutaric acid. The 1H-NMR spectrum exhibited the presence of a residue from each of these components in the intact molecule. The fast-atom bombardment mass spectrum of the methyl ester derivative indicated a prominent ion at m/z 477, probably corresponding to [M + 1] ion. Other strains of V. parahaemolyticus were also found to produce this compound when grown in an iron-limited medium.

Cell Fractionation↗
PubMed1992

Accelerated expression of secreted alpha-chain gene in anaphylactoid purpura.

The mechanisms of the elevation of serum IgA levels in anaphylactoid purpura were investigated. Serum IgA levels were significantly elevated within 2 weeks (5 to 14 days for all 12 patients) after onset in patients with anaphylactoid purpura. Serum IgM and IgG were not elevated. Although the percentages of surface IgA-bearing cells were not increased in the patients, the numbers of IgA-secreting cells within 2 weeks after onset in the patients with anaphylactoid purpura were significantly higher than those of controls. In northern blot analysis on lymphocytes, the secreted alpha (alpha s)-chain gene was well expressed compared with the membrane-bound alpha (alpha m)-chain gene, within 2 weeks after the onset of anaphylactoid purpura. Therefore, stimulation by a certain agent or a certain immune response may accelerate expression of the alpha s-chain gene in anaphylactoid purpura.

Blotting, Northern↗
PubMed1992

Bioavailabilities of calcium, phosphorus and magnesium from whey mineral complex in growing male rats.

The bioavailabilities of Ca, P and Mg from whey mineral complex (WMC) were studied from the viewpoint of the mineral balance and bone properties in growing male rats and compared with bovine bone ash (BBA) and CaCO3. Ca source showed no significant effect on feed intake, body weight gain or feed efficiency (p < 0.05). When the dietary Ca level was 0.3%, the dry weight of the femur in rats fed WMC was significantly higher than that in rats fed BBA. The femur P content of rats fed 0.3% Ca as WMC was significantly higher than that of rats fed BBA or CaCo3. The breaking energy of the femur from rats fed WMC was significantly higher than that from rats fed BBA at a Ca level of 0.2% or 0.3%. There was the same tendency in bone densities as was observed in breaking properties. There was no significant difference in quantitative values for Ca balance among three groups of rats, whereas those rats fed WMC had a significantly higher P retention than other groups. Ca bioavailability from WMC and the effect on the utilization of P and Mg were discussed.

Animals↗
PubMed1992

Lymphocyte responses to food antigens in food sensitive patients with allergic tension-fatigue syndrome.

Scores of radioallergosorbent test (RAST) for cow's milk or buckwheat flour and proliferative responses of peripheral blood mononuclear cells (PBMCs) to bovine serum albumin and beta-lactoglobulin or buckwheat flour were measured in cow's milk or buckwheat flour sensitive patients with allergic tension-fatigue syndrome. In all 3 cow's milk sensitive patients with allergic tension-fatigue syndrome, RAST scores for cow's milk were negative or slightly positive, but PBMCs well responded to bovine serum albumin and beta-lactoglobulin, but not to ovalbumin. In a buckwheat flour sensitive patient with allergic tension-fatigue syndrome, RAST scores for buckwheat flour were negative, but PBMCs well responded to buckwheat flour, but not to ovalbumin, bovine serum albumin and beta-lactoglobulin. Conversely, in cow's milk or buckwheat flour sensitive patients with immediate allergic symptoms, RAST scores for offending foods were positive although PBMCs did not respond to offending food antigens. These results suggest that proliferative responses of PBMCs to food antigens are very useful for detection of offending foods in allergic tension-fatigue syndrome.

Adolescent↗