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H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 145 records · Page 8Linked to original sources
PubMed2000

KB-R7943 inhibits store-operated Ca(2+) entry in cultured neurons and astrocytes.

We have studied cyclopiazonic acid (CPA)-sensitive store-operated Ca(2+) entry (SOCE) in cultured neurons and astrocytes and examined the effect of 2-[2-[4-(4-nitrobenzyloxy)phenyl]]isothiourea (KB-R7943), which is often used as a selective inhibitor of the Na(+)-Ca(2+) exchanger (NCX), on the SOCE. CPA increased transiently intracellular Ca(2+) concentration ([Ca(2+)](i)) followed by a sustained increase in [Ca(2+)](i) in neurons and astrocytes. The sustained increase in [Ca(2+)](i) depended on the presence of extracellular Ca(2+) and inhibited by SOCE inhibitors, but not by a Ca(2+) channel inhibitor. CPA also caused quenching of fura-2 fluorescence when the cells were incubated in Mn(2+)-containing medium. KB-R7943 at 10 microM inhibited significantly CPA-induced sustained increase in [Ca(2+)](i) in neurons and astrocytes. KB-R7943 also inhibited CPA-induced quenching of fura-2 fluorescence in the presence of extracellular Mn(2+). These results indicate that cultured neurons and astrocytes possess SOCE and that KB-R7943 inhibits not only NCX but also SOCE.

Animals↗
PubMed2000

Desensitization, surface expression, and glycosylation of a functional, epitope-tagged type I PACAP (PAC(1)) receptor.

To study desensitization and glycosylation of the type I pituitary adenylate cyclase-activating polypeptide (PACAP) receptor (PAC(1)R), a hemagglutinin (HA) epitope was inserted within the N-terminal extracellular domain, allowing immunological detection of PAC(1)R both in intact and permeabilized cells. PAC(1)R was tagged without loss of functions in ligand binding and ligand-stimulated cAMP production. In transiently transfected COS-7 cells, PAC(1)R was localized both in the plasma membrane and the cytoplasm around the nucleus. By immunoblot analysis, the immunoreactive bands with relative molecular masses ranging from 45 to 70 kDa were detected in the membrane fractions of PAC(1)R-expressing COS-7 cells. Digestion of the membranes with endoglycosidase F or treatment of the cells with tunicamycin decreased the size of the receptor to major bands of smaller size (approximately 45 and 48 kDa), suggesting that these two forms of PAC(1)R represent core proteins. Flow cytometric analysis indicated that the agonist promoted a disappearance of cell surface receptor. In accordance with this observation, preexposure of cells to PACAP38 induced a desensitization of PAC(1)R to the agonist response, although it did not cause a reduction in PAC(1)R mRNA or protein level and even slightly elevated them. These results suggest that agonist-induced desensitization of PAC(1)R involves the receptor sequestration.

Amino Acid Sequence↗
PubMed2000

Intrathecal methylprednisolone for intractable postherpetic neuralgia.

BACKGROUND: There is no effective treatment for intractable postherpetic neuralgia. Because there is evidence that postherpetic neuralgia has an inflammatory component, we assessed treatment with intrathecally administered methylprednisolone to reduce pain in patients with this disorder. METHODS: We enrolled 277 patients who had had intractable postherpetic neuralgia for at least one year, 270 of whom were followed for two years. The patients were randomly assigned to receive intrathecal methylprednisolone and lidocaine (3 ml of 3 percent lidocaine with 60 mg of methylprednisolone acetate, 89 patients), lidocaine alone (3 ml of 3 percent lidocaine, 91 patients), or no treatment (90 patients) once per week for up to four weeks. Each weekly dose was injected into the lumbar intrathecal space. Pain was evaluated before randomization, at the end of the treatment period, and then four weeks, one year, and two years later. Samples of cerebrospinal fluid were obtained for measurement of interleukin-8 before and at the end of the treatment period. RESULTS: There was minimal change in the degree of pain in the lidocaine-only and control groups during and after the treatment period. In the methylprednisolone-lidocaine group, the intensity and area of pain decreased, and the use of the nonsteroidal antiinflammatory drug diclofenac declined by more than 70 percent four weeks after the end of treatment. No complications related to intrathecal methylprednisolone were observed. Before treatment, the concentrations of interleukin-8 in the cerebrospinal fluid were inversely related to the duration of neuralgia in all the patients (r=-0.49, P<0.001). In the patients who received methylprednisolone, interleukin-8 concentrations decreased by 50 percent, and this decrease correlated with the duration of neuralgia and with the extent of global pain relief (P<0.001 for both comparisons). CONCLUSIONS: The results of this trial indicate that the intrathecal administration of methylprednisolone is an effective treatment for postherpetic neuralgia.

Aged↗
PubMed2000

Na(+)-Ca(2+) exchanger isoforms in rat neuronal preparations: different changes in their expression during postnatal development.

We examined the relative amounts of Na(+)-Ca(2+) exchanger (NCX) isoform mRNAs in cultured neurons, astrocytes and developmental rat brain. NCX1 transcript was predominant in neurons and astrocytes, but NCX2 transcript was about four-fold higher than NCX1 or NCX3 transcript in adult rat cortex. NCX2 transcript in the cortex increased markedly during postnatal development, whereas NCX1 and NCX3 transcripts decreased. Na(+)-dependent 45Ca(2+) uptake in the cortical homogenate increased significantly during postnatal development.

Animals↗
PubMed2000

Non-invasive in vivo magnetic resonance imaging assessment of acute aflatoxin B1 hepatotoxicity in rats.

Acute aflatoxin B1 (AFB1)-induced hepatotoxicity was assessed in vivo in male Sprague-Dawley rats (150-300 g) using magnetic resonance imaging (MRI). MRI results were compared to serum enzyme levels, histology and electron microscopy. Twenty-four hours following intraperitoneal delivery of AFB1 (3 mg/kg body weight in a saline/dimethyl sulfoxide (DMSO; 0.03 ml/kg body weight) solution), regions of damage, characterised by increased proton signal intensities in T2-weighted images, were observed in the vicinity of the hepatic portal vein (HPV) and in the right medial regions of the liver. Image analysis of regions of apparent damage around the HPV and right medial regions, following 24 h of AFB1 exposure, indicated statistically significant (P<0.05) increases in proton image signal intensities, when compared to saline/DMSO-treated rats. No significant difference in proton image signal intensities were observed 1-2 h following AFB1 exposure. Twenty-four hours following AFB1 exposure, histopathological assessment was characterised by portal/central vein/artery congestion, sinusoid congestion, nuclear pyknosis and karyolysis, and hepatocyte vacuolation; electron microscopy (EM) examination indicated nuclear debris, swollen cytoplasmic compartments, vacuolation, and the disappearance of the smooth endoplasmic reticulum, and elevated levels of serum aspartate aminotransferase and alanine aminotransferase were found to be significantly different (P<0.01) than controls.

Aflatoxin B1↗
PubMed2000

CD134L engagement enhances human B cell Ig production: CD154/CD40, CD70/CD27, and CD134/CD134L interactions coordinately regulate T cell-dependent B cell responses.

CD134 is a member of the TNFR family expressed on activated T cells, whose ligand, CD134L, is found preferentially on activated B cells. We have previously reported that the CD70/CD27 interaction may be more important in the induction of plasma cell differentiation after the expansion phase induced by the CD154/CD40 interaction has occurred. When CD134-transfected cells were added to PBMCs stimulated with pokeweed mitogen, IgG production was enhanced in a dose-dependent fashion. Addition of CD134-transfected cells to B cells stimulated with Staphylococcus aureus Cowan I strain/IL-2 resulted in little if any enhancement of B cell IgG production and proliferation. We found that while CD134-transfected cells induced no IgG production by themselves, it greatly enhanced IgG production in the presence of CD40 stimulation or T cell cytokines such as IL-4 and IL-10. The addition of CD134-transfected cells showed only a slight increase in the number of plasma cells compared with that in the culture without them, indicating that an increased Ig production rate per cell is responsible for the observed enhancing effect of CD134L engagement rather than increase in plasma cell generation. These results strongly suggest different and sequential roles of the TNF/TNFR family molecules in human T cell-dependent B cell responses through cell-cell contacts and the cytokine network.

Adjuvants, Immunologic↗
PubMed2000

Laser-hole boring into overdense plasmas measured with soft X-Ray laser probing

A laser self-focused channel formation into overdense plasmas was observed using a soft x-ray laser probe system with a grid image refractometry (GIR) technique. 1.053 &mgr;m laser light with a 100 ps pulse duration was focused onto a preformed plasma at an intensity of 2x10(17) W/cm (2). Cross sections of the channel were obtained which show a 30 &mgr;m diameter in overdense plasmas. The channel width in the overdense region was kept narrow as a result of self-focusing. Conically diverging density ridges were also observed along the channel, indicating a Mach cone created by a shock wave due to the supersonic propagation of the channel front.

Journal Article↗
PubMed2000

L-lactate inhibits L-cystine/L-glutamate exchange transport and decreases glutathione content in rat cultured astrocytes.

In several brain pathologies, the level of brain L-lactate increases. The stimulation of L-lactate production is a detrimental factor in promoting neuronal cell damage and astrocytic dysfunction. Astrocytic glutathione metabolism has an important role to protect brain cells against oxidative stress. In this study, effects of L-lactate on L-cystine uptake and glutathione level in rat-cultured astrocytes were examined. L-Lactate decreased the L-(35)S-cystine and Na(+)-independent L-(3)H-glutamate uptakes into astrocytes at the concentrations more than 2.5 mM. The L-lactate-induced decrease in L-(35)S-cystine uptake was neither affected by modification of extracellular pH nor mimicked by acetate, propionate and butyrate. The apparent Km value of the L-(35)S-cystine uptake was increased by L-lactate, while the Vmax was not changed. Astrocytic glutathione and nonprotein thiol content was decreased by incubation with 20 mM L-lactate for 48 hours (65% and 75% of control values, respectively). The decreases in astrocytic glutathione and nonprotein thiol content were restored to normal levels by withdrawal of L-lactate. These results suggest that L-lactate inhibits astrocytic L-cystine/L-glutamate exchangers and affects the glutathione contents.

Animals↗
PubMed2000

Cooperative roles of Bozozok/Dharma and Nodal-related proteins in the formation of the dorsal organizer in zebrafish.

In vertebrates, specification of the dorso-ventral axis requires Wnt signaling, which leads to formation of the Nieuwkoop center and the Spemann organizer (dorsal organizer), through the nuclear accumulation of beta-catenin. Zebrafish bozozok/dharma (boz) and squint (sqt), which encode a homeodomain protein and a Nodal-related protein, respectively, are required for the formation of the dorsal organizer. The zygotic expression of boz and sqt in the dorsal blastoderm and dorsal yolk syncytial layer (YSL) was dependent on the maternally derived Wnt signal, and their expression at the late blastula and early gastrula stages was dependent on the zygotic expression of their own genes. The dorsal organizer genes, goosecoid (gsc) and chordin (din), were ectopically expressed in wild-type embryos injected with boz or sqt RNA. The expression of gsc strictly depended on both boz and sqt while the expression of din strongly depended on boz but only partially depended on sqt and cyclops (cyc, another nodal-related gene). Overexpression of boz in embryos defective in Nodal signaling elicited the ectopic expression of din but not gsc and resulted in dorsalization, implying that boz could induce part of the organizer, independent of the Nodal proteins. Furthermore, boz; sqt and boz;cyc double mutants displayed a severely ventralized phenotype with anterior truncation, compared with the single mutants, and boz;sqt;cyc triple mutant embryos exhibited an even more severe phenotype, lacking the anterior neuroectoderm and notochord, suggesting that Boz/Dharma and the Nodal-related proteins cooperatively regulate the formation of the dorsal organizer.

Animals↗
PubMed2000

Rapid and sensitive XAFS using a tunable X-ray undulator at BL10XU of SPring-8.

The design and performance of the high-brilliance XAFS facility at BL10XU of SPring-8, aimed at rapid and sensitive measurement of X-ray absorption fine structure (XAFS), is reported. Both undulator gap and double-crystal monochromator have been successfully controlled covering a wide energy range (5-30 keV). A versatile goniometer system, consisting of two independent high-precision goniometers, is capable of polarized XAFS in fluorescence mode and surface-sensitive experiments using a grazing-incidence geometry. By sharing major components, i.e. a monolithic Ge 100-pixel array detector and a closed-cycle He cryostat, both polarized XAFS and X-ray standing wave (XSW) experiments can be performed at low temperature (15-300 K). The performance of the spectrometer has been evaluated by recording XAFS spectra in transmission mode.

Journal Article↗
PubMed2000

Synthesis of ethyl 2-acetamido-6-S-(5-amino-5-deoxy-beta-D- arabinopyranosyl)-2-deoxy-1,6-dithio-beta-D-glucopyranoside: a sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide.

A novel pseudo-disaccharide having an imino sugar residue at the non-reducing end, namely, a sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide, which is a potential specific inhibitor for glycosidases that recognize not only the glycosidic linkage but also the aglycone moiety, was synthesized. Glycosidation of N-Boc-5-amino-5-deoxy-D-arabinose with ethyl 2-acetamido-3,4-di-O-acetyl-2-deoxy-1,6-dithio-beta-D- glucopyranoside in the presence of TsOH gave exclusively the corresponding 1,2-cis-linked thioglycoside. The interglycosidic linkage proved stable enough under conditions for the deprotection of the N-Boc group with TFA. This pseudodisaccharide was unstable at pH > 5, but stable at lower pH. The sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide was shown to be formed from 5-amino-5-deoxy-D-arabinose and ethyl 2-acetamido-2-deoxy-1,6-dithio-beta-D-glucopyranoside in an acidic buffer solution.

Disaccharides↗
PubMed2000

Galactosyl transfer ability of beta-(1-->4)-galactosyltransferase toward 5a-carba-sugars.

Bovine beta-(1-->4)-galactosyltransferase was assayed with a series of 5a-carba-sugars, i.e., sugar analogues in which the ring oxygen of pyranose is replaced by a methylene group. The analogues are 5a-carba-sugar of 2-acetamido-2-deoxy-alpha-DL-galactopyranose, both alpha and beta anomers of 2-acetamido-2-deoxy-DL-glucopyranose (5a-carba-DL-GlcNAc), and 2-acetamido-2-deoxy-DL-mannopyranose. Of these analogues, both alpha and beta anomers of 5a-carba-DL-GlcNAc act as an acceptor. Enzymatic synthesis using the alpha and beta anomers of 5a-carba-DL-GlcNAc afforded the corresponding D-Gal-beta-(1-->4)-5a-carba-alpha-D-GlcNAc and D-Gal-beta-(1-->4)-5a-carba-beta-D-GlcNAc on a practical scale, and these structures were confirmed by NMR spectroscopy. These results indicate that the ring oxygen atom in the 5a-carba-D-GlcNAc is not used for specific recognition by bovine beta-(1-->4)-galactosyltransferase.

Animals↗
PubMed2000

Zebrafish Dkk1 functions in forebrain specification and axial mesendoderm formation.

We identified a zebrafish homologue of Dickkopf-1 (Dkk1), which was previously identified in Xenopus as a Wnt inhibitor with potent head-inducing activity. Zebrafish dkk1 is expressed in the dorsal marginal blastoderm and also in the dorsal yolk syncytial layer after mid-blastula transition. At later blastula stages, the expression expands to the entire blastoderm margin. During gastrulation, dkk1-expressing cells are confined to the embryonic shield and later to the anterior axial mesendoderm, prospective prechordal plate. Embryos, in which dkk1 was ectopically expressed, exhibited enlarged forebrain, eyes, and axial mesendoderm such as prechordal plate and notochord. dkk1 expression in the dorso-anterior mesendoderm during gastrulation was prominently reduced in zebrafish mutants bozozok (boz), squint (sqt), and one-eyed pinhead (oep), which all display abnormalities in the formation and function of the Spemann organizer and axial mesendoderm. dkk1 expression was normal in these embryos during the blastula period, indicating that zygotic functions of these genes are required for maintenance but not establishment of dkk1 expression. Overexpression of dkk1 suppressed defects in the development of forebrain, eyes, and notochord in boz mutants. Overexpression of dkk1 promoted anterior neuroectoderm development in the embryos injected with antivin RNA, which lack most of the mesoderm and endoderm, suggesting that Dkk1 can affect regionalization of neuroectoderm independently of dorso-anterior mesendoderm. These data indicate that Dkk1, expressed in dorsal mesendoderm, functions in the formation of both the anterior nervous system and the axial mesendoderm in zebrafish.

Amino Acid Sequence↗
PubMed2000

Cytomorphometric differentiation of intraductal proliferative breast lesions.

BACKGROUND: Although cytologic examination has been an indispensable procedure for the diagnosis of various breast diseases, it is often difficult to make a precise diagnosis of intraductal proliferative breast lesions preoperatively. The present study attempts to clarify the differentiation of the lesions by the cytologic morphometric approach. METHODS: Cytologic specimens from 21 intraductal lesions, including nine ductal carcinomas in situ (DCIS), seven ductal hyperplasias (DH), and five papillomas were evaluated. Using a microscope connected to a computerized video system, the mean nuclear area, the perimeter, the form factor, the largest to smallest diameter ratio of the nuclei (LS ratio), and the coefficient of variation of the nuclear area (NACV) were measured and analyzed. RESULTS: The mean nuclear area and perimeter were significantly higher in the cases of DCIS than in DH (p < 0.01) and papilloma (p < 0.005). Similarly, DCIS had higher NACV values than the other groups (p < 0.05 and p < 0.005, respectively). There were no significant differences in form factor or LS ratio. CONCLUSIONS: The quantitative estimation of cytologic nuclear features is useful for preoperative differential diagnosis of intraductal proliferative lesions of the breast.

Adult↗
PubMed2000

Quantitative ultrasound as a predictor of node metastases and prognosis in patients with breast cancer.

BACKGROUND: A retrospective study was performed to determine whether preoperative quantitative ultrasound assessment could predict axillary lymph node metastases and prognosis in patients with breast cancer. We focused on the presence of a halo, which is one of the features of breast cancer on ultrasound and represents reflections from the invading margin around infiltrating malignancies. METHODS: We evaluated ultrasonography from 187 infiltrating breast carcinoma patients with tumors 5 cm or less in greatest dimension (T1, T2). Using computer image analysis, the halo area (H) and the sum of the area of halo and internal echo (total tumor area (T)) were measured, and the ratio of halo to entire tumor (H/T, halo ratio) was calculated and compared with lymph node status and prognosis. RESULTS: The mean of the halo ratio was 0.38+/-0.13. Using the value of 0.42 as a cut-off, the high halo ratio group had significantly worse prognoses for both overall and disease-free survival at 49 months in median follow-up (p <0.001 and p <0.0005, respectively). The specificity of a high halo ratio in the T1 classification for predicting axillary node metastasis was 83.1%, with a negative predictive value of 86.8%. In patients with tumors 1.0 cm or smaller, the negative predictive value was 100%. In a multivariate analysis, halo ratio was an independent predictor of disease-free survival of breast carcinoma patients (p =0.0232). CONCLUSIONS: Preoperative quantitative ultrasound may be a useful non-invasive method for predicting the presence of axillary lymph node metastases and prognosis in patients with primary breast cancer.

Adult↗
PubMed2000

Changes of CD4/CD8 ratio and interleukin-16 in systemic lupus erythematosus.

The authors investigated changes in the ratio of CD4+ to CD8+ T cells (CD4/CD8 ratio) and T-cell activation, indicated by human leukocyte antigen (HLA)-DR expression, in patients with systemic lupus erythematosus (SLE) following treatment. An increase was observed in the CD4/CD8 ratio as well as a decrease in the expression of HLA-DR on T cells with the improvement of clinical manifestations on treatment with steroids or cyclosporine (CSA). In addition, steroid treatment suppressed whereas CSA treatment exerted no perceptible influence on the serum interleukin (IL)-16 level, concurrent with changes in T-cell phenotypes. This indicated that the mechanism of the change in the CD4/CD8 ratio differed depending on the drug, and CD8+ T cells could play an important role in reducing this ratio. The CD4/CD8 ratio and HLA-DR expression may be good indicators of therapeutic efficacy in some SLE patients.

Adrenal Cortex Hormones↗