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S Hayashi

Publications and source records attributed to S Hayashi.

At least 325 records · Page 18Linked to original sources
PubMed1999

Modulation of proinflammatory cytokines by nitric oxide in murine acute lung injury.

We tested the hypothesis that NO synthase inhibition alters proinflammatory cytokine expression during acute lung injury in mice. Five-week-old CD-1 mice were pretreated with l-NAME or d-NAME and then received an intratracheal injection of endotoxin (or PBS). TNF-alpha and IL-6 ELISAs and RT-PCR were performed on lung homogenates sampled 6 h later. l-NAME increased TNF-alpha and IL-6 protein and mRNA expression in lungs. Immunostaining demonstrated that TNF-alpha was expressed predominantly by macrophages in the lung. l-NAME did not alter pulmonary macrophage concentration. To better understand the effect of NO synthase inhibition, elicited murine peritoneal macrophages were stimulated in vitro with LPS after addition of l-NAME, d-NAME, nitroprusside, or control. Nuclear proteins were extracted 3 h later and electrophoretic mobility shift and supershift assays were performed using radiolabeled NF-kappaB consensus sequence oligonucleotides. Endotoxin increased NF-kappaB p50/p65 heterodimer binding. Binding was further increased by l-NAME and decreased by nitroprusside. The effect of nitroprusside was not blocked by guanylate cyclase inhibition. We conclude that, in endotoxin-induced acute lung injury, NO synthase inhibition increases proinflammatory cytokine protein and mRNA expression in part because NO decreases the amount of NF-kappaB available for binding to the regulatory region of proinflammatory cytokine genes.

Animals↗
PubMed1999

Altered pharmacokinetics of indinavir by a novel nonnucleoside reverse transcriptase inhibitor (HBY-097): a pharmacokinetic evaluation in HIV-positive patients.

HBY-097 (HBY), an investigational nonnucleoside reverse transcriptase inhibitor (NNRTI), and indinavir (IDV) share a common metabolic pathway, cytochrome P4503A4 (CYP3A4), and may clinically be used together as well as with zidovudine (ZDV). Thus, the potential pharmacokinetic (PK) interaction between these drugs was evaluated. HBY (500 mg Q8H), IDV (800 mg Q8H), and ZDV (200 mg Q8H) were given to 8 HIV-infected subjects. Serial plasma samples were collected at baseline (ZDV and IDV alone) and day 11 (all 3 drugs) to determine PK parameters using noncompartmental analysis. PK parameters for ZDV in the presence and absence of HBY were not appreciably different. However, both the maximum (Cmax) and minimum (Cmin) concentrations of IDV were significantly reduced, from a mean of 7514 +/- 1636 and 146 +/- 81 mcg/L to 4725 +/- 2494 mcg/L and 54 +/- 24 mcg/L (p < .05) after addition of HBY. Furthermore, apparent clearance (CL/F) of IDV before and after 11 days of concomitant HBY administration was significantly higher, from 0.69 +/- 0.14 to 1.94 +/- 0.63 L/h/kg (p < .05) with an associated reduction in area under the curve (AUC0-8) from 16,034 +/- 4903 to 6134 +/- 2701 mg/L/h (p < .05). The increase in IDV CL/F is consistent with the observed metabolic induction effects of other NNRTIs. The results of this trial showed that HBY significantly alters the pharmacokinetic parameters of IDV at the dose studied.

Adult↗
PubMed1999

Proximal to distal cell communication in the Drosophila leg provides a basis for an intercalary mechanism of limb patterning.

Proximodistal patterning in the Drosophila leg is elaborated from the circular arrangement of the proximal domain expressing escargot and homothorax, and the distal domain expressing Distal-less that are allocated during embryogenesis. The distal domain differentiates multiply segmented distal appendages by activating additional genes such as dachshund. Secreted signaling molecules Wingless and Decapentaplegic, expressed along the anterior-posterior compartment boundary, are required for activation of Distal-less and dachshund and repression of homothorax in the distal domain. However, whether Wingless and Decapentaplegic are sufficient for the circular pattern of gene expression is not known. Here we show that a proximal gene escargot and its activator homothorax regulate proximodistal patterning in the distal domain. Clones of cells expressing escargot or homothorax placed in the distal domain induce intercalary expression of dachshund in surrounding cells and reorient planar cell polarity of those cells. Escargot and homothorax-expressing cells also sort out from other cells in the distal domain. We suggest that inductive cell communication between the proximodistal domains, which is maintained in part by a cell-sorting mechanism, is the cellular basis for an intercalary mechanism of the proximodistal axis patterning of the limb.

Animals↗
PubMed1999

Interplay of Notch and FGF signaling restricts cell fate and MAPK activation in the Drosophila trachea.

The patterned branching in the Drosophila tracheal system is triggered by the FGF-like ligand Branchless that activates a receptor tyrosine kinase Breathless and the MAP kinase pathway. A single fusion cell at the tip of each fusion branch expresses the zinc-finger gene escargot, leads branch migration in a stereotypical pattern and contacts with another fusion cell to mediate fusion of the branches. A high level of MAP kinase activation is also limited to the tip of the branches. Restriction of such cell specialization events to the tip is essential for tracheal tubulogenesis. Here we show that Notch signaling plays crucial roles in the singling out process of the fusion cell. We found that Notch is activated in tracheal cells by Branchless signaling through stimulation of &Dgr; expression at the tip of tracheal branches and that activated Notch represses the fate of the fusion cell. In addition, Notch is required to restrict activation of MAP kinase to the tip of the branches, in part through the negative regulation of Branchless expression. Notch-mediated lateral inhibition in sending and receiving cells is thus essential to restrict the inductive influence of Branchless on the tracheal tubulogenesis.

Animals↗
PubMed1999

Repression of the wing vein development in Drosophila by the nuclear matrix protein plexus.

The wing of Drosophila is separated into several sectors by the wing veins. Vein primordia are specified by the positional information provided by hedgehog and decapentaplegic in the wing imaginal disc and express the key regulatory gene rhomboid. One model of this process is that boundaries of gene expression regulated by hedgehog or decapentaplegic provide reference points where rhomboid transcription is activated. We present an analysis of the gene plexus, whose loss of function causes an excess vein phenotype. Molecular cloning revealed that plexus encodes a novel 1990-amino acid protein with cysteine-rich motifs. Plexus protein was ubiquitously expressed and was tightly associated with the nuclear matrix. In plexus mutant wing imaginal discs, an anteroposterior positional coordinate was established normally as revealed by the wild-type pattern of spalt major and knirps expression. However, the expression of several vein-specific and intervein-specific genes was misregulated, as if they had neglected the positional coordinate. These results suggest that Plexus is an essential component of a global repressor of vein differentiation. Although Plexus protein was expressed in vein primordia of the wing disc, it does not appear to interfere with vein differentiation in the normal position. A genetic epistasis test between px and knirps suggests that plexus acts downstream of knirps. We propose that the vein differentiation takes place by inactivation of the plexus-mediated repression by prepattern genes such as knirps. Plexus may regulate transcription of vein-and intervein-specific genes by tethering transcriptional regulators to specific locations in the nucleus.

Amino Acid Sequence↗
PubMed1999

Properties of partially purified beta-N-acetylglucosaminidase from bovine crystalline lens.

This paper reports that beta-N-acetylglucosaminidase from bovine lens has potent enzyme activity compared with other glycosidases in the lens. The partially purified enzyme was used to determine its physiological properties. The optimal pH and optimal temperature of this enzyme was approximately 6.3 and 40 degrees C, respectively. The apparent native molecular weight of this enzyme obtained by gel filtration chromatography was 540 kDa. Furthermore, the enzyme fraction contained 3 polypeptides with molecular weights of 28.8, 28.0 and 26.0 kDa, although it is not certain if they were one of the components of this enzyme in the current study. The Km value of this enzyme was 92.3 microM and it was inhibited strongly by HgCl2 and sodium dodecyl sulfate (SDS).

Acetylglucosaminidase↗
PubMed1999

Isolation and some properties of a novel killer toxin-like protein produced by Streptomyces sp. F-287.

A killer toxin-like protein was found in the culture supernatant of a strain isolated from soil. The strain was classified and designated as Streptomyces sp. F-287. The molecular weight of the purified killer toxin-like protein was estimated to be 9,500 by SDS-PAGE. The purified protein was heat stable (100 degrees C, 5 min), pH stable (pH 6.0-9.0, 60 degrees C, for 30 min), and had a relatively wide action spectra. The SKLP showed a cytocidal effect on both budding yeast, Saccharomyces cerevisiae W303 (IC50 = 15.6 micrograms/ml) and on fission yeast, Schizosaccharomyces pombe SP870 (IC50 = 20.0 micrograms/ml). The SKLP also caused morphological changes on some sensitive yeasts and filamentous fungi. These characteristics are apparently different from known killer toxins. These results suggest that this is a novel killer toxin-like protein from Streptomyces sp. strain F-287.

Amino Acid Sequence↗
PubMed1999

Heterogeneous localizations of Trk B among individual periodontal Ruffini endings in the rat incisor.

The present immunocytochemical study examined the localization of Trk B, a high affinity neurotrophin receptor, in the neural elements of the periodontal ligament of the rat incisor. In light microscopy, the immunoreactivity was demonstrated in dendritic profiles in the alveolar half of the periodontal ligament. Their location and morphological features indicated that they were periodontal Ruffini endings. Occasional rounded cells associated with periodontal Ruffini endings, which had immunonegative kidney-shaped nuclei, were immunoreactive; these were judged to be terminal Schwann cells. Immunoelectron microscopy revealed the heterogeneous localization of Trk B among individual Ruffini endings. Some terminal Schwann cells contained immunoreactive products for Trk B in the cytoplasm, while others did not. Similarly, a part of the Schwann sheaths covering the axon terminals showed Trk B immunoreactivity. Most axon terminals associated with periodontal Ruffini endings were immunopositive for Trk B, though a few of them were immunonegative. The ordinary Schwann cells did not contain Trk B immunoreactive products. These findings imply that Trk B is required for the maintenance of periodontal Ruffini endings. The different expression pattern of Trk B suggests that neuronal and glial elements comprising individual periodontal Ruffini endings are subject to heterogeneous conditions with regard to the requirement of Trk B.

Animals↗
PubMed1999

Labeled carcinoembryonic antigen antibodies excitable by infrared rays: a novel diagnostic method for micro cancers in the digestive tract.

OBJECT: An indocyanine green derivative (ICG-sulfo-OSu) was used as the labeling substance for monoclonal antibody, and a fluorescence imaging system appropriate for ICG-sulfo-OSu excitable by infrared rays (IR) was developed. The goal of this study was to demonstrate antibody labeling at the tissue level using this new imaging system. MATERIALS AND METHODS: ICG-sulfo-OSu labeled mouse anti-human carcinoembryonic antigen (CEA) monoclonal antibody, a newly developed imaging system, and an infrared ray microscope were employed in this experiment. Paraffin sections of human colon cancer previously proven to have cross-reactivity to anti-CEA antibody were examined. RESULTS: Positive staining was seen as a brownish discoloration of oxidized 3,3'-diaminobenzidine tetrahydrochloride (DAB) in sections that reacted with ICG-sulfo-OSu-labeled anti-CEA antibody, and the fluorescence was well-matched with the oxidized DAB-positive sites. CONCLUSION: Specific antibodies labeled with ICG-sulfo-OSu have significant affinity to cancer cells and seem to reflect sufficient amounts of fluorescence by IR to be useful in a system for the endoscopic detection of micro cancers using the immunohistochemical staining method.

Adenocarcinoma↗
PubMed1999

[A case of myelodysplastic syndrome associated with IgA nephropathy].

A 72-year-old man was admitted for examination of dyspnea and pitting edema of the lower legs in July, 1996. His hemoglobin level was 6.9 g/dl, and myelodysplastic syndrome (MDS) was revealed by bone marrow aspiration, and frequent transfusions were needed. His renal function rapidly deteriorated in the middle of August (BUN 45 mg/dl, Cr 4.8 mg/dl) and IgA nephropathy (IgAN) with marked intestinal nephritis was disclosed by renal biopsy. In November, joint manifestations of warmth and pain, which suggested arthritis, appeared at the bilateral wrist and ankle joints. Soon after receiving prednisolone (20 mg/day), the arthritis was relieved. Renal function also improved (BUN 41 mg/dl, Cr 21 mg/dl) and frequent transfusions were no longer necessary. This is a case with various clinical manifestations of MDS, IgAN, and arthritis, and appears to be the first MDS case complicated with IgAN. A number of case reports have identified immune abnormalities in patients with MDS. Immune and bone marrow abnormalities have been reported to be involved in the pathogenesis of IgAN. Thus, MDS could be complicated by IgAN. Their pathogenetic association is discussed in this paper.

Aged↗
PubMed1999

[Acquired stuttering associated with callosal infarction: a case report].

A 66-year-old right-handed man with acquired stuttering was reported. He complained of paresis in his left leg and speech dysfluency. He was not aphasic in terms of comprehension and writing. His speech dysfluency was mainly characterized by initial syllable repetitions. He has apraxia with his left hand, but has neither agraphia with his left hand nor crossed optic ataxia. MRI showed cerebral infarction in the truncus of the corpus callosum, and angiography revealed occlusion of the right anterior cerebral artery. 99mTc HM-PAO SPECT showed decreased blood flow in the right frontal lobe. Within six months of its onset, the patient's speech dysfluency had diminished. As the causative lesion for acquired stuttering, we proposed a hemispheric lesion in addition to a callosal lesion.

Aged↗
PubMed1999

[Two cases of bladder tumor producing granulocyte colony stimulating factor].

Two cases of bladder tumor producing granulocyte colony-stimulating factor (G-CSF) are reported. The first case was in a 79-year-old female patient. A large bladder tumor was diagnosed as right-sided hydronephrosis. The tumor consisted mostly of squamous cell carcinoma with a few transitional cells. Total cystectomy could not be performed because of direct invasion by the tumor into the pelvis. The patient died without aggressive treatment about 7 months after admission. Her leukocyte count consistently increased up to 76,200/mm3. The serum G-CSF levels were not analyzed. However, immunohistochemical examination revealed a high concentration of G-CSF in the tumor specimen. The other case was in an 80-year-old male patient. The patient, who had refused total cystectomy for bladder tumor (transitional cell carcinoma, grade 2, T2N0M0) 2 years earlier, underwent ureterocutaneostomy for obstructive renal insufficiency. Total cystectomy was not performed at this admission because of tumor invasion into the rectum and his advanced age. Radiotherapy was administered. However, he developed ileus caused by direct tumor invasion into the ileum. He died about 10 months after the urinary diversion. Leukocytosis, which improved transiently following radiotherapy, became more severe. The maximum leukocyte count was 49,500/mm3 just before death. The serum G-CSF levels during and after radiotherapy were 54 pg/ml and < 30 pg/ml, respectively. Immunohistochemical examination revealed the presence of G-CSF in the tumor. These findings suggest the production of G-CSF by the bladder tumor.

Aged↗
PubMed1999

[Reticulated platelet determination: methodologies and applications for the evaluation of thrombocytopenic disorders].

Reticulated platelets retain some residual mRNA in their cytoplasm and are thought to be newly produced platelets. In recent years, it has been reported that the reticulated platelet count (RP) correlates well with platelet production. For that reason, the measurement of RP (%) is considered useful for analyses of platelet kinetics and differential diagnoses of thrombocytopenic disorders. However, certain technical difficulties exist because fluorochrome thiazole orange (TO), which is used for staining purposes, stains platelet granules nonspecifically, and so far, only a few reports have documented the study of precision staining techniques. We evaluated staining criteria precisely in an effort to solve the issue of nonspecific staining by TO, and concluded that the important points for effective staining were (1) fixation of platelets, (2) 1:8 dilution of TO (ReticCount), (3) incubation for 1 to 2 hours, and (4) the capture of platelets using anti-CD42b monoclonal antibody. We stained reticulated platelet samples by the above method and achieved intra-assay reproducibility of 3.4-5.1% RP (%) in normal subjects was 8.7 +/- 2.2%. It was significantly higher (23.6 +/- 13.3%) in patients with idiopathic thrombocytopenic purpura (ITP), and elevated in 87% of all evaluated ITP patients. Our method is sensitive, provides reproducible results, and can be effectively utilized for the analysis of platelet kinetics and differential diagnosis of thrombocytopenia.

Adult↗
PubMed1999

Monitoring of human herpesviruses after allogeneic peripheral blood stem cell transplantation and bone marrow transplantation.

Herpesviruses frequently cause serious complications after allogeneic bone marrow transplantation (allo-BMT). Recent studies have shown more rapid immune reconstitution after allogeneic peripheral blood stem cell transplantation (allo-PBSCT) compared with allo-BMT. However, it has not been clarified whether the improved immune reconstitution after allo-PBSCT is associated with a lower incidence of herpesvirus infections. We monitored the emergence of Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and HHV-7 DNA by a nested-double polymerase chain reaction in peripheral blood leucocytes from 22 allo-BMT and 16 allo-PBSCT patients. Each virus had an unique temporal profile of detection. HHV-6 DNA was detected most frequently at 3 weeks after transplantation, whereas CMV and EBV DNA were detected later (2-3 months). Detection rates of HHV-6 DNA at 3 and 4 weeks after allo-BMT were significantly higher than those after allo-PBSCT (9/16 v 2/13 at 3 weeks, P < 0.01; 10/21 v 1/15 at 4 weeks, P < 0.01). Detection rates of the other three herpesviruses after the two types of allogeneic transplantation were not significantly different throughout observation period. Furthermore, detection of HHV-6 DNA within the first 4 weeks was associated with delayed platelet engraftment after both allo-BMT and allo-PBSCT (P < 0.01). These results suggest an advantage for allo-PBSCT over allo-BMT in terms of suppression of HHV-6 reactivation and prevention of subsequent complications.

Adolescent↗