Search PubMed⌕ Search

Biomedical subjects

H Hayashi

Publications and source records attributed to H Hayashi.

At least 613 records · Page 34Linked to original sources
PubMed1997

Pathological characterization of astrocytic hyaline inclusions in familial amyotrophic lateral sclerosis.

To clarify the pathological characteristics of astrocytic hyaline inclusions (Ast-HIs) in patients with familial amyotrophic lateral sclerosis (FALS) with neuronal Lewy-body-like hyaline inclusions (LBHIs), eight autopsies on members of four different families, including two long-term surviving patients with clinical courses of over 10 years, were analyzed. Ast-HIs were found only in the two long-term surviving patients who belonged to different families and to different races. Ast-HIs were ultrastructurally composed of 15- to 25-nm granule-coated fibrils that had immunoreactivities to superoxide dismutase 1 (SOD1) and ubiquitin. Approximately 50% of the Ast-HIs expressed alpha B-crystallin, metallothionein, glutamine synthetase, and tubulin (alpha and beta) at various intensities. Some Ast-HIs reacted with antibodies to tau protein, S-100 protein, and heat shock protein 27. The Ast-HIs were not stained for glial fibrillary acidic protein. Our results suggest a cooperative role of superoxide dismutase 1, ubiquitin, and cytoskeletal proteins in the formation of granule-coated fibrils (namely, Ast-HIs) and provide evidence that Ast-HIs are formed in certain long-surviving familial amyotrophic lateral sclerosis patients with neuronal Lewy-body-like hyaline inclusions.

Adult↗
PubMed1997

[A case of superficial siderosis of the central nervous system with bilateral vestibular dysfunction].

A 58-year-old woman developed slowly progressive hearing loss, anosmia, and unsteady gait. She had neither repeated episode of headache nor a past history of neurosurgical operation or head injury. Neurological examination revealed anosmia, moderate degree of sensorineural hearing loss. She showed loss of caloric response bilaterally. No nystagmus was found. Romberg sign was present. No cerebellar ataxia was noted in the finger-to-nose or the heel-to-knee test. No adiadochokinesis was noted. Deep tendon reflexes were increased in both upper and lower extremities. Sensation was intact. She showed disturbance of the righting reflex in the tilt-table examination. CSF were under normal pressure, xanthochromic with siderophages. CSF total protein and ferritin level were elevated. T2-weighted image (TE4000/TR100) of high field strength magnetic resonance imaging (MRI) showed marginal hypointensity of the brain stem, the Sylvian fissures, the tips of temporal lobes, anterior cerebellar surfaces and the entire spinal cord. Angiography of the cerebral vessels and spinal arteries failed to identify the source of bleeding. It seemed likely that she had lost bilateral vestibular and auditory functions caused by hemosidelin deposition to her eighth nerves which are often affected by this disorder. Her disturbance of gait and station was apparently similar to cerebellar ataxic gait, however, she did not have limb ataxia. The electronystagmogram revealed marked degree of vestibular dysfunction (VOR) and relative sparing of cerebellar function (OKN). Her disturbance of the righting reflex in the tilt-table examination and the characteristic feature of her Romberg sign with directional preponderance also indicate that the bilateral loss of vestibular functions, i.e., vestibular ataxia caused her dysequilibrium syndrome. It is our impression that vestibular ataxia might precede cerebellar ataxia commonly reported so far.

Brain↗
PubMed1997

[Clinical efficacy of post-TUR prophylactic chemotherapy for superficial bladder cancer--the result of co-operative prospective randomized trial].

We have performed a prospective randomized clinical trial of post-operative prophylactic therapy for superficial bladder cancer since October in 1991. The criteria were as follows; age < or = 80 y.o., Ta/T1, TCC G1/G2, without CIS lesion and resectable cancer by TUR. The therapeutic arm was divided into three as follows: arm A intracystic instillation with Epirubicin; arm B: oral administration with 5-FU; arm C: combination of arm A and arm B. The number of registered patients were 20 in arm A, 18 in arm B, and 18 in arm C. The patient characteristics in every group were not significantly different. The prophylactic efficacy of arm A was superior to that in the other two groups.

Administration, Intravesical↗
PubMed1997

The clamp fixation method in cemented total knee arthroplasty. Dynamic experimental and radiographic studies of the tibial baseplate clamper.

The clamp fixation method using the Tibial Baseplate Clamper in total knee arthroplasty (TKA) is a superior procedure compared to conventional cement fixation methods. A dynamic experimental study and a radiographic study were performed to make sure the efficiency of the clamp fixation method was satisfactory. As a result, this procedure showed the large initial pressure force and a lack of variance in the force applied over time, and also it had a large depth of cement penetration compare to the pusher method. The clamp fixation method will help the surgeon achieve excellent cement fixation in TKAs because it has the many advantages of a gentle, yet strong, constant, and, most importantly, simple approach surgeons can use to reduce operating time while cementing all three prostheses simultaneously.

Arthritis, Rheumatoid↗
PubMed1997

BayK 8644 increases resting calcium spark frequency in ferret ventricular myocytes.

BayK 8644, an L-type Ca2+ channel agonist, has been shown to increase sarcoplasmic reticulum (SR) Ca2+ release in dog and ferret ventricular muscle. The visualization of local increase in cytosolic Ca2+ concentration, called the "Ca2+ spark", has enabled us to investigate the elementary events of the BayK-induced Ca2+ release from the SR. In this study, the effects of BayK on twitch Ca2+ transients and Ca2+ sparks were examined in ferret ventricular myocytes with laser scanning confocal microscopy and a fluorescent calcium indicator, fluo 3. BayK converted the post rest potentiation of twitch Ca2+ transients to decay. The Ca2+ spark frequency under control conditions was fairly constant during 20 s of rest after interruption of electrical stimulation. BayK (100 nM) increased the spark frequency by 465.7 +/- 90.3% of control but did not change the spatial and temporal characteristics of the individual sparks. The increase in spark frequency by BayK was not affected by perfusion with Ca(2+)-free solution, but was suppressed by the addition of nifedipine (10 microM), suggesting that the BayK effects on Ca2+ sparks were mediated by the sarcolemmal dihydropyridine (DHP) receptor, but.were independent of Ca2+ influx. These findings suggest that BayK activates SR Ca2+ release at rest through a putative linkage between the sarcolemmal DHP receptor and the SR ryanodine receptor.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1997

The advantage of gastrectomized patients in management of their chronic hepatitis C.

Because the majority of patients with chronic hepatitis C do not respond to interferon, alternative treatments need to be established. Several lines of evidence suggest that iron depletion is beneficial for such patients. Thus, gastrectomized patients with a reduced capacity for iron absorption might have an advantage in treatment of their liver damage over patients with intact gastrointestinal tracts. Four male gastrectomized patients had post-transfusion chronic hepatitis C. The iron load in three patients was adjusted below 10 ng/ml of serum ferritin level by phlebotomy. Subsequent interferon treatment for the four patients without iron load cleared circulating hepatitis C virus RNA in one patient only. However, serum ferritin concentrations were stabilized at low levels without maintenance phlebotomy, and sustained normalization of serum liver enzyme activities was obtained in all four patients. Similar treatments were done for 10 male patients with intact gastrointestinal tracts. The amount of removed iron from these patients was more than that from gastrectomized patients. Interferon also failed to clear circulating hepatitis C virus RNA except in one case. Low ferritin levels and sustained normalization of liver enzymes were seen in three patients. A transient elevation of ferritin levels with low enzyme activities was seen in two patients. Relapsing hepatitis was seen in five of the seven patients who needed maintenance phlebotomy due to a rebound in serum ferritin levels, probably because of active iron absorption from the intestine. Our data suggest that depletion of cytotoxic iron is a key to managing patients with chronic hepatitis C.

Adult↗
PubMed1997

Synthesis and properties of oligonucleotide derivatives containing a hydrophobic fluorescent dye at the 2'-position.

The oligonucleotides containing 2'-(6-dimethylamino-2-naphthamide)uridine [U(DAN)] at the different position were synthesized by the fully automated solid phase phosphoramidite methods. The UV melting profiles for the U(DAN)-modified oligonucleotides with complementary DNA exhibited sigmoidal curves whose shapes were similar to those for the unmodified duplexes.

Automation↗
PubMed1996

Epitope-tagging of a functional thyrotropin receptor: detection of the native receptor on intact cells.

To facilitate immunological detection of thyrotropin receptor (TSHR), we inserted a c-myc epitope within the unique, 50 amino acid segment of the ectodomain (TSHRmyc). When stably expressed in 293 human embryonal kidney (HEK) cells, TSHRmyc demonstrated high affinity TSH binding and the ability to produce cAMP in response to TSH. Binding of the myc monoclonal antibody 9E10 to 293-TSHRmyc cells could be detected with [125I] anti-mouse IgG. No competition was observed between TSH and 9E10 binding to 293-TSHRmyc. Immunoprecipitation by 9E10 of TSHRmyc revealed TSHR forms of approximately 95 and approximately 100 kDa. Endoglycosidase digestion identified the approximately 95 kDa species as the single chain precursor with high mannose carbohydrate. The approximately 100 kDa single chain receptor contained mature, complex carbohydrate. No smaller species of TSHR subunits or proteolytic fragments was observed. Again TSH did not inhibit immunoprecipitation of TSHRmyc by 9E10. These data demonstrate that the normally functioning c-myc epitope-tagged TSHR can be detected directly and in native form with a readily available anti-myc 9E10 and without the need for prior affinity capture. Lack of competition between 9E10 and TSH suggests that at least part of the 50 amino acid segment in TSHR ectodomain is not a TSH binding site. This epitope-tagged TSHR will be valuable for further studies on the synthesis and trafficking of TSHR.

Antibodies, Monoclonal↗
PubMed1996

Gq-coupled receptors transmit the signal for GLUT4 translocation via an insulin-independent pathway.

Guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) induces the translocation of glucose transporter type 4 (GLUT4) from an intracellular pool to the cell surface and increases glucose uptake in adipocytes. The GTP-binding protein(s) responsible for the translocation has remained to be identified. Using a sensitive and quantitative method to assess the translocation of c-MYC epitope-tagged GLUT4, we obtained evidence that the activation of receptor-coupled Gq (neither Gi nor Gs) triggered GLUT4 translocation in cells, independently of insulin signaling pathway(s). Platelet-activating factor (PAF) induced GLUT4 translocation in the cells expressing the Gi- and Gq-coupled PAF receptor, but the translocation was induced even after pretreatment with wortmannin, an islet-activating protein and phorbol 12, 13-dibutyrate. Norepinephrine triggered GLUT4 translocation in cells expressing the Gq-coupled alpha1-adrenergic receptor, but prostaglandin E2 did not cause GLUT4 translocation in cells expressing the Gs-coupled EP4 receptor or the Gi-coupled EP3alpha receptor. The norepinephrine-stimulated GLUT4 translocation and glucose uptake via Gq may possibly contribute to the fuel supply required for thermogenesis in brown adipocytes and for the enhanced contractility in cardiomyocytes, both of which have an abundant endogenous GLUT4.

3T3 Cells↗
PubMed1996

Microsphere embolism-induced changes in presynaptic function of the cerebral cortex in rats.

The present study was undertaken to elucidate pathophysiological changes in the cortical presynaptic function, K(+)-stimulated calcium influx, noradrenaline release and noradrenaline uptake, on the 1st and 3rd days after microsphere embolism in rats. Voltage-dependent calcium channels were characterized pharmacologically using three types of calcium channel blockers, L-type (nifedipine and diltiazem), N-type (omega-conotoxin GVIA), and P-type channel (omega-agatoxin IVA) blockers. K(+)-stimulated calcium influx of the normal rat synaptosome was inhibited by 100 nM omega-agatoxin IVA, but not by 10 microM nifedipine, 10 microM diltiazem and 100 nM omega-conotoxin GVIA. Calcium influx of the cortical nerve terminals of the right hemisphere was decreased on the 1st and 3rd days after the embolism. Noradrenaline release and uptake were also decreased on the 1st and 3rd days after the embolism. However, the percent release of noradrenaline was not altered. The results suggest that P-type channels are predominant in the cerebrocortical nerve terminals in rats and that calcium influx, noradrenaline release and uptake in the cerebrocortical nerve terminals are decreased by microsphere embolism. The decrease in noradrenaline release may be mainly due to a reduction in the activity of noradrenaline uptake in cerebrocortical nerve terminals of the microsphere-embolized rat.

Animals↗
PubMed1996

Atomic force microscopy proposes a novel model for stem-loop structure that binds a heat shock protein in the Staphylococcus aureus HSP70 operon.

The Staphylococcus aureus HSP70 operon produces a polycistronic RNA in response to heat shock, and ORF37 is the first protein to be translated. The promoter of this operon contains a palindromic nucleotide sequence that may form a stem-loop structure. Structural analysis of the promoter regions by atomic force microscopy (AFM) revealed a quadruplet that consists of a pair of stem-loops. A novel "SL2S' (Stem-Loop-Loop-Stem) model was proposed for this structure. AFM also revealed the binding of ORF37 to the quadruplet, establishing a molecular mechanism for this heat shock gene expression; ORF37 acts as a regulator by binding to the SL2S structure in the promoter.

Base Sequence↗
PubMed1996

Cloning and characterization of the tyrB gene from Salmonella typhimurium.

We found a gene homologous to tyrB, which encodes aromatic amino acid aminotransferase (ArAT, EC2.6.1.57) in Escherichia coli, in the genome of Salmonella typhimurium IFO 13245. The S. typhimurium tyrB product consists of 397 amino acid residues. The amino acid sequence shows 87.9% identity with that of E. coli ArAT, but shows lower identity (42.3%) with that of E. coli aspartate aminotransferase (AspAT, EC2.6.1.1). When the S. typhimurium tyrB gene was expressed in an E. coli mutant whose intrinsic tyrB gene had been inactivated, the activity of transaminating tyrosine and phenylalanine could be recovered, indicating that the S. typhimurium tyrB gene product possesses transamination activities similar to those of the E. coli ArAT. Elucidation of the molecular features of a new ArAT may be helpful for structural and functional analyses of ArAT and AspAT with regard to the different but overlapping substrate specificity of the two enzymes.

Amino Acid Sequence↗
PubMed1996

Inhibition of agonist-induced Ca2+ entry in endothelial cells by myosin light-chain kinase inhibitor.

Identification of the signal which links the depletion of Ca2+ stores to a Ca2+ entry pathway in the plasma membrane remains to be determined. In the present study, effects of ML-9 and wortmannin, inhibitors of myosin light-chain kinase (MLCK), on agonist-stimulated Ca2+ response were investigated in porcine aortic endothelial cells loaded with the Ca(2+)-sensitive dye fura-2. Bradykinin (BK) caused a rapid increase in [Ca2+]i, followed by a sustained increase due to the influx of Ca2+ from the extracellular space. ML-9 almost completely abolished the sustained increase in [Ca2+]i in BK-stimulated cells, while it did not affect the mobilization of Ca2+ from intracellular stores. ML-9 also abolished the sustained increase in [Ca2+]i caused by thapsigargin. Wortmannin mimicked the effect of ML-9 on the thapsigargin-stimulated Ca2+ response. These findings document for the first time the involvement of MLCK inhibitor in Ca2+ signaling in endothelial cells.

Androstadienes↗
PubMed1996

Relationship between serum levels of interleukin 6, various disease parameters and malnutrition in patients with esophageal squamous cell carcinoma.

Serum levels of interleukin 6 (IL-6) are correlated with the disease status and prognosis in cancer patients. IL-6 is also an important mediator of experimental cancer cachexia. We investigated the production of IL-6 and IL-6 receptors and expression of IL-6 mRNA by esophageal squamous carcinoma cells using immunohistochemical staining and in situ reverse transcription-PCR. We also measured levels of serum IL-6 using an ELISA in 50 patients with esophageal squamous cell carcinoma (ESCC) to determine the correlation between serum levels of IL-6 and clinicopathological factors IL-6 mRNA was expressed in the primary tumor. Esophageal squamous carcinoma cells produced both IL-6 and IL-6 receptor. IL-6 concentrations were significantly higher in the primary tumor than in the normal epithelium. The incidences of weight loss, tumor invasion to adjacent organs, and noncurative resection were significantly higher in ESCC patients with serum levels of IL-6 > or = 7 pg/ml (n = 13, group C) compared with patients with serum levels <7 pg/ml and > or = 3 pg/ml (n = 14, group B) and <3 pg/ml (n = 23, group A). Tumor size and C-reactive protein levels were significantly higher and albumin levels were significantly lower in group C. Results suggest that IL-6, which is produced by tumor cells, may be related to various disease parameters as well as to the nutritional status in patients with ESCC.

Adult↗