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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 541 records · Page 30Linked to original sources
PubMed1997

Amplification of rfbE and fliC genes by polymerase chain reaction for identification and detection of Salmonella serovar Enteritidis, Dublin and Gallinarum-Pullorum.

Polymerase chain reaction (PCR) primers for O9 antigen (rfbE) and phase 1 flagellin antigen (fliC) were designed for the rapid identification and detection of Salmonella serovar Enteritidis and Dublin. The rfbE primer pairs selectively amplified the rfbE region of group O9 Salmonella serovars. The fliC primer pairs amplified the DNAs of g,m and g,p-type flagellar antigen; Salmonella serovar Enteritidis, Dublin, and Essen. However, DNA from flagellar-negative Salmonella serovar Gallinarum-Pullorum was also amplified. The sensitivity of PCR primer pairs was 10(4) CFU/assay by boiled DNA preparation and 10(2) CFU/assay by proteinase K-treated DNA preparation.

Carbohydrate Epimerases↗
PubMed1997

c-myc, c-erbB-1 and c-erbB-2 expressions in urothelial carcinoma.

The expression of c-myc, c-erbB-1 and c-erbB-2 in 24 cases of urothelial carcinoma by Southern and northern blot analysis, and immunohistochemistry was examined. The results were compared with the pathological grade and stage. We found elevated mRNA expressions of c-myc and c-erbB-1 in 19 and 11 of 21 cases, respectively, but there was no apparent amplification or rearrangement of these oncogenes in any of the cases examined. By immunohistochemistry using anti-epidermal growth factor receptor antibody, most of the cases showed positive immunoreactivity on the cancer cell membranes, and cancers of higher pathological grade and stage showed more intense staining. By contrast, amplification of c-erbB-2 was detected in four of 24 cases, all of which were assigned to a high pathological grade (G3). Elevated c-erbB-2 mRNA levels appeared to correlate with the pathological grade of the cancers. Positive immunohistochemical reactions to c-erbB-2 were found in the cancer cell membranes in three of 24 cases, which were accompanied by amplification and elevated mRNA levels of c-erbB-2. In conclusion, expressions of c-myc, c-erbB-1 and c-erbB-2 were all elevated in the majority of urothelial carcinomas, but the amplification was not universal.

Blotting, Northern↗
PubMed1997

Inhibition of PAH transport by parathyroid hormone in OK cells: involvement of protein kinase C pathway.

We have previously shown that the p-aminohippurate (PAH) transport system in OK kidney epithelial cell line is under the regulatory control of protein kinase C. Parathyroid hormone (PTH) could activate protein kinase C, as well as protein kinase A, in OK cells. In the present study, the effect of PTH on PAH transport was studied in OK cells. PTH inhibited the transcellular transport of PAH from the basal to the apical side, as well as the accumulation of PAH in OK cells. Basolateral PAH uptake was inhibited by PTH in a dose- and time-dependent manner. Protein kinase A activators did not affect the transcellular transport or the accumulation of PAH. The PTH-induced inhibition of the accumulation of PAH was blocked by a protein kinase C inhibitor staurosporine. These results suggest that PTH inhibits the PAH transport in OK cells and that the messenger system mediated by protein kinase C, not protein kinase A, plays an important role in the regulation of PAH transport by PTH.

1-Methyl-3-isobutylxanthine↗
PubMed1997

A case of scurvy rarely encountered in Japan.

We report a case of scurvy, which is rarely encountered in Japan. A 75-year-old male was hospitalized with diffuse subcutaneous hemorrhaging of both feet, pain on walking, and shortness of breath. A remarkably low serum level of vitamin C was confirmed. Administration of ascorbic acid dramatically improved his clinical symptoms. Improvement paralleled the increase of serum vitamin C level. This case underscores the important role of vitamin C on the integrity function of the vessel wall.

Aged↗
PubMed1997

Interaction of arenastatin A with porcine brain tubulin.

Arenastatin A, isolated from the Okinawan marine sponge Dysidea arenaria, is an antimitotic depsipeptide containing a 16-membered ring. Interaction of the compound with tubulin was investigated by the use of [3H]arenastatin A and other microtubule disruptors. Scatchard analysis indicated the presence of one binding site for arenastatin A per tubulin heterodimer with a dissociation constant (Kd) of 1.8 x 10(-6) M. Rhizoxin was a competitive inhibitor of arenastatin A binding, and vinblastine also inhibited arenastatin A binding in a partially competitive manner. Arenastatin A had no inhibitory effect on colchicine binding to tubulin.

Animals↗
PubMed1997

Photoaffinity labeling of tumor promoter-binding protein (CN-TPBP) and preparation of affinity sorbent gels.

Cytosolic-nuclear tumor promoter-specific binding protein (CN-TPBP) was photoaffinity-labeled with a specific ligand, 3beta,5alpha-dihydroxycholestan-6-one (YS-64). Analysis by ODS-HPLC of peptide fragments obtained from the labeled CN-TPBP by trypsinization indicated the existence of a single specifically labeled site. Affinity gels for the purification of CN-TPBP were then prepared. As ligands for the affinity gels, 12-O-tetradecanoylphorbol 13-acetate (TPA), a typical phorbol-type tumor promoter, and benzolactam-V8-310 (BL-V8-310), a structural/biological mimic of teleocidin-class tumor promoters, were adopted. The use of these gels afforded a protein that showed a single band of 58 kDa on SDS-PAGE.

Affinity Labels↗
PubMed1997

Photoaffinity labeling of the ligand-interacting helix of the retinoic acid receptor alpha.

Two photoaffinity-labeling probes for retinoic acid receptor (RAR) alpha, 4-[(3-(3-(trifluoromethyl)-3H-diazirin-3-yl)phenyl)carboxamido]ben zoic acid (3DIAM) and its para-isomer (4DIAM), were designed and synthesized. Both compounds possess high affinity for recombinant RAR alpha (MBP-RAR alpha/E) and bind covalently to its cognate ligand-binding site. The labeled site of MBP-RAR alpha/E with 3DIAM was determined, by the endoproteinase combination method, to be located in helix 11 of the ligand-binding domain of RAR alpha, which is the position at which the ligand is considered to bind, on the basis of the reported crystal structure of the retinoic acid/RAR gamma complex.

Azirines↗
PubMed1997

Polyenylidene thiazolidinedione derivatives with retinoidal activities.

Several polyenylidene thiazolidine or 2-thioxo-4-thiazolidinone derivatives were synthesized and their retinoidal activities were examined in terms of the differentiation-inducing ability towards human promyelocytic leukemia HL-60 cells and inhibitory effect on interleukin (IL)-1 alpha-induced IL-6 production in MC3T3-E1 cells. Compounds containing a trimethylcyclohexenyl ring induced HL-60 cell differentiation with weaker activity than retinoic acid (1a) by one or two orders of magnitude. The thiazolidinedione derivatives (2, 5, 7) showed stronger activity than the corresponding 2-thioxo-4-thiazolidinone derivatives (3, 6, 8). The effects of a retinoid antagonist (LE540) and synergists (retinoid X receptor (RXR) agonists, HX600 or HX630) on the activities of thiazolidine derivatives indicate that these compounds elicit their activities through the nuclear retinoic acid receptors (RARs). All the thiazolidines examined also inhibited IL-1 alpha-induced IL-6 production with IC50 values of 10 nM order. The retinoidal activities of the thiazolidines are significant, considering that replacement of the carboxylic acid in retinoid structures with bioisosteric functional groups is generally ineffective, as seen in the structure-activity relationships of retinoidal benzoic acids.

Cell Differentiation↗
PubMed1997

Structural identification of a major cytokinin in coconut milk as 14-O-(3-O-[beta-D-galactopyranosyl-(1-->2)-alpha-D-galactopyranosyl- (1-->3)-alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabinofuranosyl)- beta-d-galactopyranosyl)-trans-zeatin riboside.

A cytokinin isolated from the fluid endosperm of Cocos mucifera L. (coconut milk), accounting for more than 20% of the total cytokinin activity, was structurally analyzed by NMR techniques, mass spectrometry, and sugar analysis by high performance liquid chromatography (HPLC). The planar structure of the cytokinin was deduced from its NMR and mass spectrometric data. The structure of the sugar moiety, including its absolute structure, was determined by HPLC analysis of alditol acetates and aldononitrile acetates derived from the cytokinin. The configuration of the sugar-sugar bonds was determined by NMR, and the structure was finally identified as 14-O-(3-O-[-beta-D-galactopyranosyl-(1-->2)-alpha-galactopyranosyl-(1--> 3)- alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabino-furanosyl)-beta-D- galactopyranosyl)-trans-zeatin riboside.

Carbohydrate Sequence↗
PubMed1997

[Novel biological response modifiers: phthalimides with TNF-alpha production regulating activity].

Tumor necrosis factor alpha (TNF-alpha), an important cytokine produced mainly by activated macrophages, plays a critical role in certain physiological immune systems. But it causes severe damage to the host when produced in excess. Therefore, TNF-alpha can be regarded to possess both favorable and unfavorable effects. These pleiotropic effects indicated that TNF-alpha production-enhancers in some cases and TNF-alpha production-inhibitors in other cases would be useful as biological response modifiers (BRMs) under various circumstances. A possible lead compound is thalidomide, which had been used as a hypnotic/sedative agents but was withdrawn from the market because of it's teratogenicity. Thalidomide is a specific inhibitor of TNF-alpha production, and this effect has been shown to be useful for the treatment of various immunodiseases. Recently, we found that the regulation of TNF-alpha production by thalidomide and related hthalimides was both inducer-specific and cell-type-specific, i.e., (I) the compounds enhance 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced TNF-alpha production by HL-60 cells, while they inhibit TPA-induced TNF-alpha production by another human leukemia cell line THP-1, and (II) the compounds inhibit TNF-alpha production both by HL-60 and THP-1 cells when the cells are stimulated with okadaic acid. We also found that in a optically active phthalimide analogues of thalidomide the inducer specific bi-directional regulation of TNF-alpha production is separated. This implies that the target molecule(s) of the two systems are different each other.

Depression, Chemical↗
PubMed1997

Inhibitory effects of insulin on intracellular calcium and aggregatory response of platelets are impaired in hypertensive subjects with insulin resistance.

To determine the effects of insulin on intracellular calcium and platelet aggregatory responses in hypertensive subjects with insulin resistance, we measured insulin sensitivity in terms of glucose disposal rate (GDR) by the hyperinsulinemic euglycemic clamp technique (GC) in 14 non-diabetic untreated hypertensive subjects, and determined basal ([Ca2+]i) and thrombin-stimulated (T-[Ca2+]i) platelet-free calcium concentrations and thrombin-stimulated platelet aggregatory response (AG) before (PRE[Ca2+]i, T-PRE[Ca2+]i, and PRE AG, respectively) and during (POST[Ca2+]i, T-POST[Ca2+]i, and POST AG, respectively) GC. As a control for GC, vehicle (normal saline) was infused on another day. No significant difference was observed between PRE[Ca2+]i and POST[Ca2+]i, T-PRE[Ca2+]i and T-POST[Ca2+]i, or PRE AG and POST AG, GDR inversely correlated with delta[Ca2+]i (POST [Ca2+]i-PRE[Ca2+]i, r = -0.75, p < 0.02), delta T-[Ca2+]i, (T-POST[Ca2+]i-T-PRE[Ca2+]i, r = -0.63, p < 0.02) and delta AG (POST AG-PRE AG, r = -0.67, p < 0.01). No significant changes were observed in these variables during vehicle infusion. [Ca2+]i, T-[Ca2+]i, and AG decreased during GC as compared with baseline in hypertensive subjects with normal insulin sensitivity, but were unchanged in those with insulin resistance, suggesting that the vasodilatory and anti-platelet aggregatory effects of insulin are impaired in patients with insulin-resistant hypertension.

Adult↗
PubMed1997

Production of a monoclonal antibody (59.4) against canine lymphocyte surface antigen and its immunohistochemical application.

A monoclonal antibody was produced by immunizing BALB/c mice with freshly prepared canine thymocytes and peripheral blood leukocytes. The antibody, designated 59.4, was of the IgG1 subclass type and mainly reacted with lymphocytes. In single-color flow cytometric analysis, lymphocytes from the peripheral blood, thymus and spleen were graded into three categories according to their fluorescence intensity labeling by antibody 59.4: weakly, moderately and intensely positive cells. Two-color analysis revealed that a major population of CD8-positive cells were intensely labeled by antibody 59.4, but less than 50% of CD4-positive cells were moderately reacted with antibody 59.4. Immunohistochemically, thymocytes in the medulla showed moderately intense immunoreactivity to 59.4, but most lymphocytes in the cortex were negative in reaction. Immunostaining using antibody 59.4 demonstrated characteristic aggregations of 59.4-positive lymphocytes in the reticulum cell-free region of the thymic medulla. In the spleen, scattered lymphocytes in the outer layer of the marginal zone and in the red pulp were intensely labeled by antibody 59.4, while lymphocytes gathering in the mantle zone and periarterial lymphatic sheath (PALS) were moderately stained. Antibody 59.4 appears to recognize an antigen which is expressed by a more-differentiated T cell-lineage but not by immature T cells in the thymic cortex.

Animals↗
PubMed1997

An evaluation of neuromuscular reversal with edrophonium in a patient with malathion intoxication.

We evaluated the neuromuscular reversal with edrophonium using peripheral nerve stimulator and recorder in a patient with malathion intoxication. Edrophonium 10 mg i.v. caused an increase in single twitch tension by 76% of the control during the recovery phase from an acute cholinergic crisis 16 days after ingestion of malathion solution. The present study indicated that edrophonium test seems to be a reliable monitoring in evaluating neuromuscular reversal in the patient with acute malathion insecticide poisoning.

Adult↗
PubMed1997

Neuromuscular blocking actions of the aminoglycoside antibiotics sisomicin and micronomicin in the rabbit.

The neuromuscular blocking actions of sisomicin sulfate (SISO), micronomicin sulfate (MCR) and d-tubocurarine (dTc) were studied in 20 rabbits anesthetized with halothane. The i.v. administration of SISO 20-40 mg/kg, MCR 40-80 mg/kg or dTc 0.1-0.3 mg/kg resulted in dose-dependent decreases in twitch tension. The ED50s for SISO, MCR and dTc were 23.5, 58.2 and 0.2 mg/kg, respectively. SISO- and MCR-induced neuromuscular blockade was partially antagonized by neostigmine or by calcium.

Aminoglycosides↗
PubMed1997

Three-dimensional analysis of multiple wear vectors in retrieved acetabular cups.

The wear of polyethylene acetabular components is an important issue in total hip arthroplasty. The amount of wear has been measured in many studies, but few have addressed other mechanical aspects of wear in vivo. We used the shadowgraph method to measure the wear vectors in 104 retrieved acetabular cups that had been made by a single manufacturer, and we identified more than one wear vector in thirty-one cups (30 per cent). We hypothesized that the most likely explanation of multiple wear vectors was loosening of the acetabular implant with a change in the orientation of the implant in the pelvis. To test this hypothesis, we estimated the extent of motion of the cup in situ on the basis of differences in angles measured from serial radiographs of sixteen hips. We then used linear transformation of the three-dimensional vectors to compare the wear directions measured in the retrieved implants with the wear directions predicted from the radiographs. The change in wear direction predicted on the basis of in vivo motion of the cup never corresponded to the actual difference between wear vectors in the retrieved implants. Our results suggest that multiple wear vectors may be commonly found in retrieved implants, but loosening of the acetabular cup does not account for the multiple vectors. Additional observations suggest that impingement between the edge of the acetabular cup and the femoral component may be associated with multiple wear vectors. These results have implications for the investigation of the general mechanisms of wear in vivo and suggest that clinical or wear-testing scenarios that assume a single direction of wear may underestimate the over-all amount of volumetric wear.

Equipment Failure Analysis↗
PubMed1997

Fatality due to severe Salmonella enteritis associated with acute renal failure and septicemia.

A 66-year-old man was hospitalized for abdominal pain and diarrhea of more than 10 times a day. He had been under regular medication with prednisolone for rheumatoid arthritis. On admission, laboratory data and clinical examination indicated inflammation, dehydration, acute renal failure with a high level of serum musculogenic enzyme (creatine kinase), and ileus. Salmonella enteritidis was isolated from his fecal and blood samples. The patient died within 24 hours after admission, and autopsy showed hemorrhagic necrotic enteritis localized to the ileum. Enterocolitis due to Salmonella enteritidis, which is usually an acute self-limited gastrointestinal illness, may occasionally be a serious and lethal disease.

Acute Kidney Injury↗