[Establishment of Sendai virus gene manipulation and its applications].
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
A Kato
Publications and source records attributed to A Kato.
An improved method for chromosome counting in maize.
An improved method for counting chromosomes in maize (Zea mays L.) is presented. Application of cold treatment (5C, 24 hr), heat treatment (42 C, 5 min) and a second cold treatment (5C, 24 hr) to root tips before fixation increased the number of condensed and dispersed countable metaphase chromosome figures. Fixed root tips were prepared by the enzymatic maceration-air drying method and preparations were stained with acetic orcein. Under favorable conditions, one preparation with 50-100 countable chromosome figures could be obtained in diploid maize using this method. Conditions affecting the dispersion of the chromosomes are described. This technique is especially useful for determining the somatic chromosome number in triploid and tetraploid maize lines.
Chromosomes↗
[Effect of erythromycin and clarithromycin on ion transport across dissected canine tracheal epithelium].
Since erythromycin was shown to be effective in the treatment of patients with diffuse panbronchiolitits, newly discovered effects of macrolide antibiotics have attracted much attention. It was reported that erythromycin inhibits Cl secretion across cultured canine tracheal epithelial cells. Erythromycin may decrease the movement of water toward the lumen, thus reducing sputum volume. We tested the hypothesis that erythromycin and clarithromycin have a similar effect on the dissected canine tracheal epithelium, by measuring the short circuit current using Ussing chambers. Addition of erythromycin or clarithromycin did not change the short circuit current within 20 minutes when applied on either the mucosal side or the submucosal side. No changes in the short circuit current were observed after pretreatment of the epithelium with amiloride, an Na channel blocker, or bumetanide, a Cl transport inhibitor, and subsequent addition of the macrolide antibiotics. These data indicate that neither erythromycin nor clarithromycin has any short term effect on ion transport in the dissected canine tracheal epithelium.
Animals↗
[Fine needle aspiration cytology under ultrasonographic imaging for diagnosis of thyroid tumor].
During a 66-month period, 2849 patients with thyroid gland tumor were examined by fine needle aspiration cytology (FNA) under ultrasonographic imaging at Yamada Red Cross Hospital. Of these patients, 333 received surgical therapy and histological examinations were performed. FNA yielded an accuracy of 92.4%, a specificity of 100% and a sensitivity of 88.3%. There were 16 false-negative reports which were mainly considered to be due to calcified lesions, cystic lesion, or follicular carcinoma. Among the 188 negative cases, 24 cases (12.8%) proved to be positive by repeated FNA-Preoperative FNA provides cytological information and may assist in the determination of the operative indication. This approach resulted in an increased rate of surgery of thyroid malignancies among all thyroid gland surgeries. This method need to be improved to reduce false-negative results and the combination of FNA diagnosis and other examination is necessary.
Biopsy, Needle↗
[Localization of epileptogenic foci and visualization of propagating process in the seizure discharges using crosscorrelation analysis].
Electrocorticogram (ECoG) of intractable focal epilepsy was analyzed using AR model, wavelet analysis and crosscorrelation analysis. The sequential 3-dimensional visualization technique of phase shift maps was developed to localize the epileptic foci and to study their propagation process. The crosscorrelation of the epileptic discharges was calculated between the electrodes in every unit of time, to get the phase shift. More than two epileptogenic foci were localized and two kinds of propagating process were shown. These findings suggest that two kinds of mechanism might work in development of epileptic discharges, and our newly developed visualization technique is useful to investigate the epileptogenesis etiology.
Brain Mapping↗
Contact inhibition-induced inactivation of the cyclin D-dependent kinase in rat fibroblast cell line, 3Y1.
Inhibitory proteins for Cdks (CKIs) are involved in cell cycle arrest induced by anti-mitotic factors, chemicals, or DNA damage in mammalian cells. High cell density also induces cell cycle arrest with unreplicated genomic DNA even in the presence of mitotic dose of the growth factors, termed contact inhibition. Although rat fibroblast cell line, 3Y1, arrested in quiescence by contact inhibition, Cdk4 bound its regulatory subunit, cyclin D1 or D3. However, these complexes were enzymatically inactive. Phosphorylation of the cyclin D1-bound Cdk4 by Cdk4-activating kinase, composed of cyclin H and MO15 (alias Cdk7), which was reconstituted in Spodoptera frugiperda cells (Sf9) could convert inactive cyclin D1-Cdk4 complex into active form in vitro, suggesting that threonine 172 in the Cdk4, whose phosphorylation is required for its activation, was in part unphosphorylated in the contact-inhibited 3Y1. Although MO15 was active in cell extracts prepared from the contact-inhibited 3Y1, activation of bacterially produced Cdk4 in the cell extracts was inhibited. Removing p27kip1 from the cell extracts allowed MO15 holoenzyme to phosphorylate the Cdk4 and to activate it, indicating that an access of MO15 to Cdk4 was inhibited by p27kip1 in the contact-inhibited 3Y1.
Animals↗
[Preoperative scoring and operative complications of unruptured cerebral aneurysms].
Low risk of mortality and morbidity are necessary pre-conditions for surgical treatment of unruptured cerebral aneurysms. We assessed retrospectively 132 patients with angiographically confirmed cerebral aneurysms using an unruptured aneurysm score. Among them, 84 patients were treated surgically. The score consists of the sum of scores for the following factors: associated disease (none: 0, one: 1, two or more: 2); aneurysm size (below 14 mm: 0, 15-24 mm: 1, 25 mm or more: 2); location (anterior circulation: 0, carotid cave: 1, posterior circulation: 2); and multiplicity (single: 0, two or more: 1). Eleven patients had complications and the morbidity rate including asymptomatic lesions was 13.1%. Five patients had permanent neurologic deficits (final morbidity rate 5.9%). The majority of patients with scores less than 1 underwent operations and the morbidity rate was low, whereas patients with scores between 2 and 4 had a higher morbidity rate. Preoperative scoring is useful for predicting surgical risks associated with unruptured cerebral aneurysm.
Adult↗
Prevention of amyloid-like deposition by a selective prolyl endopeptidase inhibitor, Y-29794, in senescence-accelerated mouse.
Our study was performed to assess the hypothesis that prolyl endopeptidase (PEP) would be functionally involved in the senescence-accelerated amyloid formation and that long-term inhibition of prolyl endopeptidase would suppress the progression of A beta-like deposition in the hippocampus of the senescence-accelerated mouse (SAM). Granular structures of A beta-LI were observed in the hippocampus and around cerebral microvessels of the SAM after immunohistochemical staining with specific anti-A beta antibody. Repeated treatment of the SAM with Y-29794 (1, 10, 20 mg/kg, p.o.), a specific inhibitor of prolyl endopeptidase, significantly reduced the number and density of A beta-positive granular structures in the hippocampus of the SAM, after digital image analysis with NIH Image software. Furthermore, the characteristic biphasic distribution of the digitized density of the granules was significantly modulated after the treatment with Y-29794. These results suggest that chronic treatment of the SAM with Y-29794, a nonpeptide inhibitor of prolyl endopeptidase, prevents the progression of A beta-like deposition in the hippocampus of the SAM.
Aging↗
[Regional difference in the etiology of liver cirrhosis in Iwate].
To assess regional differences in the etiology of liver cirrhosis in Iwate, we analyzed 324 patients with liver cirrhosis treated at various hospitals. The etiology was HCV 44.8%, HBV 11.1%, HBV + HCV 4.6%, alcohol 27.5% (including heavy drinkers 17.9%), PBC 1.5% and non-B non-C 10.5% in Iwate. The incidence of alcoholic cirrhosis was higher than that in other prefectures, while that of HCV was lower. Especially in the northern area of Iwate, the rate of alcoholic cirrhosis was very high (39.1%--including heavy drinkers 21.8%) while viral cirrhosis was relatively low. Although the alcohol consumption volume in Iwate was not very high, marked alcohol consumption, especially shochu, was observed in the northern area of Iwate. The volume and kind of alcohol consumed in each area differed, and the etiology of liver cirrhosis differed regionally in Iwate. Thus, we should consider these districts and levels of alcohol consumption when treating patients with liver cirrhosis.
Female↗
Y-26763 protects the working rat myocardium from ischemia/reperfusion injury through opening of KATP channels.
This investigation was undertaken to determine the possible protection against ischemia afforded by Y-26763, [(-)-(3S,4R)-4-(N- acetyl-N-hydroxyamino)-6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran- 3- ol], which has K+ channel-opening properties, in isolated rat hearts under working conditions. This preparation was subjected to 28 min of global ischemia followed by 30 min of reperfusion. Drugs were injected into the aortic cannula prior to ischemia. Compared to control, Y-26763 (1 microM) resulted in a significant recovery of post-ischemic cardiac functions, significant reduction of cellular enzyme loss, and preserved significantly the stocks of cellular high-energy phosphates and the myocyte ultrastructure. These effects of Y-26763 were completely prevented by glibenclamide (10 microM), a specific K+ channel blocker of KATP channels. In non-ischemic conditions, Y-26763 significantly increased coronary flow without affecting cardiac output and heart rate. The data were analyzed statistically by analysis of variance. The results clearly demonstrate that Y-26763 protects the myocardium from ischemic injury by opening KATP channels.
Adenosine Triphosphate↗
Molecular cloning of Limulus alpha 2-macroglobulin.
The American horseshoe crab Limulus polyphemus contains alpha 2-macroglobulin (alpha 2M) in the hemolymph plasma and hemocytes. alpha 2M from Limulus shows many of the typical characteristics of mammalian alpha 2M, including the presence of an internal thiol-ester, reactivity with a diversity of endopeptidases, a unique proteinase-trapping mechanism, and reactivity with the mammalian alpha 2M receptor. Additionally, Limulus alpha 2M has the unique property that it regulates the limulin-based hemolytic system of the plasma. A cDNA encoding Limulus alpha 2M has been obtained from a hemocyte cDNA library. The open reading frame encodes an N-terminal signal sequence of 25 amino acid residues and a mature protein of 1482 residues. The entire amino acid sequence is similar to those of the mammalian alpha 2Ms (28-29% identity) and contains common features found in mammalian alpha 2Ms. a bait region, an internal thiol-ester site, and a receptor-binding domain. However, the N-terminal portion (positions 24-105) has no sequence similarity with those of mammalian alpha 2Ms, and it is structurally related to that of the human complement factor C8 chain, consistent with a role for Limulus alpha 2M in host defense. The component sugar analysis of Limulus alpha 2M showed the existence of a complex type of oligosaccharide chain similar to those of mammalian alpha 2M. However, unlike mammalian alpha 2M, no sialic acid was detected in Limulus alpha 2M and it contained approximately 3 mol/mol N-acetylgalactosamine, suggesting the presence of O-linked sugar chains, which have not been found in mammalian alpha 2M. Expression of alpha 2M was detected in hemocytes, but not in hepatopancreas, heart, stomach, intestine, coxal gland, brain and skeletal muscle. Furthermore, immunoblotting of large and small granules of the hemocytes with antiserum against alpha 2M indicated the presence of the alpha 2M in large granules. Trypsin-treated Limulus alpha 2M, but not the native alpha 2M, displaced methylamine-treated human 125I-alpha 2M from the human alpha 2M receptor with a Kd of 30 nM, suggesting conservation of the proteinase-clearance mechanisms between mammalian and arthropod evolutionary lineages.
Amino Acid Sequence↗
Interaction of propranolol with S100 proteins of the cardiac muscle.
The cardioprotective activity of propranolol is believed to be independent of its beta-adrenoceptor antagonistic effect. Propranolol exerts this effect through a direct effect on the cardiac muscle, but the precise mechanism remains unclear. In this work, we demonstrated that propranolol binds to S100ao and S100L proteins with ED50 of approximately 1.0 microM without cation dependency and that this binding changes the conformation of these S100 proteins. Propranolol, however, was found to bind to and to change the conformation of S100C protein in the presence of Mg2+ or Zn2+ with ED50 of approximately 1.0 microM. No change was observed in the presence of Ca2+. Moreover, in the presence of Mg2+, the ED50 of L- and D- propranolol were approximately 0.8 and 2.0 microM, respectively. This study demonstrated for the first time, that the S100 proteins of the cardiac muscle are intracellular targets of propranolol, and that Mg2+ is a modulator of the cardioprotective activity of S100C protein.
Animals↗
Calystegine B4, a novel trehalase inhibitor from Scopolia japonica.
GLC-MS analysis has been developed for screening plants of the family Solanaceae for new calystegines. GLC-MS analyses of the extract of Scopolia japonica showed the presence of a new tetrahydroxy-nor-tropane alkaloid in addition to the known calystegines A3, A5, B1, B2, B3, and C1. We gave this new alkaloid the trivial name calystegine B4. The structure of calystegine B4 was determined as 1 alpha, 2 beta, 3 alpha, 4 alpha-tetrahydroxy-nor-tropane from a variety of NMR spectral data. Calystegines B1, B2, and C1 are potent competitive inhibitors with Ki values ranging from 10(-6) to 10(-7) M for almond beta-glucosidase, while calystegine B4 inhibited this enzyme in a competitive manner, with a Ki value of 7.3 microM. Calystegine B2 is also a potent inhibitor of green coffee bean alpha-galactosidase, whereas calystegine B4 exhibited no significant activity for this enzyme. Among rat intestinal glycosidases, only trehalase was potently inhibited by calystegine B4, with an IC50 value of 9.8 microM. Furthermore, calystegine B4 potently inhibited pig kidney trehalase in a competitive manner, with a Ki value of 1.2 microM, but it was almost inactive against yeast and fungal trehalases.
Alkaloids↗
Two subsites on the active center of pig kidney trehalase.
A kinetic analysis of the active site of pig kidney trehalase was made by examining two types of inhibitors that are monosaccharide analogs and cause a competitive inhibition of the trehalase. Trehalase hydrolyzes trehalose (alpha-D-glycopyranosyl alpha-D-glucopyranoside) to give an equimolar mixture of alpha-D-glucose and, by inversion of configuration, beta-D-glucose. 1,4-Dideoxyl-1,4-imino-D-arabinitol is considered to be a transition state (glucosyl cation) analog, while methyl beta-D-glucoside, 1,5-dideoxy-1,5-imino-D-glucitol (1-deoxynojirimycin), fagomine, and 1-epivalidamine are considered to be analogs of the beta-D-glucose that is derived by hydrolysis of trehalose. These glucosyl cation inhibitor and beta-D-glucose analog inhibitors competed with each other at the same site on the active center of pig kidney trehalase and were therefore put together in one group (group A). Methyl alpha-D-mannoside and 1-deoxymannojirimycin were also competitive inhibitors of trehalase and competed with each other for the same site. However, an inhibitor in group A did not compete with the methyl alpha-D-mannoside or 1,5-dideoxy-1,5-imino-D-mannitol (1-deoxymannojirimycin). Thus these latter two inhibitors were placed in group B. These results support the hypothesis that the active center of trehalase may comprise two subsites, one for catalysis and one for recognition, that act separately on each of the glucose of the trehalose. The catalysis site requires the correct D-glucose configuration at carbons 2, 3, 4, and 5 or a good superimposition onto the glucosyl cation intermediate. The C2 equatorial OH group of a glucopyranosyl residue appears to be important for binding at the catalytic site since 1-deoxynojirimycin is more tightly bound by two orders of magnitude over its 2-deoxy derivative, fagomine. The beta-D-glucose and glucosyl cation analogs best fit this site. The recognition site is compatible with D-glucose and its analogs bearing the alpha configuration at the anomeric position. alpha-D-Mannose analogs are much more tightly bound than the corresponding D-gluco compound at this site. The extremely high affinity (Ki = 0.52 nM) of validoxylamine A, a mimic of the substrate in the transition state, derives from the synergistic interactions of two cyclitol units with two subsites. The value obtained by multiplying the Ki (1.2 microM) for 1-epivalidamine times that for 1-deoxymannojirimycin (Ki = 0.39 mM) is very close to that for validoxylamine A. The results described here may be applicable to other trehalase molecules.
Animals↗
A facilitatory effect on the induction of long-term potentiation in vivo by chronic administration of antisense oligodeoxynucleotides against catalytic subunits of calcineurin.
A rise in Ca2+ concentration at postsynaptic sites provides an initial step in inducing both the long-term potentiation (LTP) and long-term depression (LTD) in the CA1 region of the hippocampus. LTP induction requires the activation of Ca(2+)-sensitive protein kinases following the rise in Ca2+. By contrast, the activity of protein phosphatase(s) appears to be critical to induce LTD. Here we demonstrate that inhibition of the synthesis of calcineurin A alpha and A beta, catalytic subunits of Ca2+/calmodulin- (CaM) dependent protein phosphatase, reduces the threshold of induction for commissural-CA1 LTP in anesthetized rats. In rats administered antisense oligodeoxynucleotides (ODNs) against calcineurin A alpha and A beta intraventricularly for 7 days, a brief tetanic stimulation to the CA3 region, which in the control case was below threshold for the induction of LTP, now produced a long-lasting increase in both the EPSP slope and the amplitude of population spike recorded from the commissural-CA1 pathway. Western blot analysis of calcineurin showed that the threshold reduction was accompanied by a selective decrease in the protein levels in the hippocampus. Thus our study provides direct evidence that calcineurin per se has an antagonizing role in LTP induction. Complementary experiments with the selective calcineurin inhibitor, FK506, also showed the reduction of LTP threshold in a dose-dependent manner. These results, together with previous studies, support the hypothesis that the quantitative phosphorylation level of critical intracellular proteins determines whether the synaptic efficacy will increase or decrease after the activity-dependent rise in postsynaptic Ca2+.
Animals↗
Evidence for a 24R,25(OH)2-vitamin D3 receptor/binding protein in a membrane fraction isolated from a chick tibial fracture-healing callus.
Explore the source record for details and available documents.
Animals↗
RpoS-dependent regulation of genes expressed at late stationary phase in Escherichia coli.
We have identified 6 Escherichia coli genomic genes, including 4 new genes, responsive to the stationary phase. One of them was regulated positively by RpoS at the stationary phase, and the remaining 5 negatively at a late stationary phase, all of them responding to multiple environmental stresses. Nucleotide sequences as well as such multiple responses revealed that those genes may have more than one overlapping-promoter recognized by different sigma-factors which regulate gene expressions during their cell growth.
Bacterial Proteins↗
Protective effect of lysozyme-galactomannan or lysozyme-palmitic acid conjugates against Edwardsiella tarda infection in carp, Cyprinus carpio L.
The protective effect of lysozyme-galactomannan or lysozyme-palmitic acid conjugates orally administered to carp, Cyprinus carpio L. was investigated using a virulent strain of Gram-negative Edwardsiella tarda isolated from an infected fish. Lysozyme-galactomannan conjugate was prepared through controlled Maillard reaction. Lysozyme-palmitic acid conjugate was prepared through base-catalyzed ester exchange using N-hydroxysuccinimide ester of palmitic acid. The conjugates provided substantial protection to carp infected with a Gram-negative bacteria fish pathogen E. tarda NG 8104. Lytic activities of lysozyme conjugates with galactomannan and palmitic acid were about 80 and 71% of native lysozyme using Micrococcus lysodeikticus as a substrate. Feeding with lysozyme conjugates, for 8 days, significantly enhanced fish protection against E. tarda infection. The survival rate was 30% for lysozyme-galactomannan conjugate treated fish and 20% for lysozyme-palmitic acid conjugate treated fish after 6 days cultivation while all control fish died within 3 days. On the other hand, a recovery rate of 40% after 6 days was observed in the fish group that were fed lysozyme-palmitic acid conjugate 3 and 2 h before and after E. tarda challenge, respectively, and for 6 consecutive days. The results of this work show the possibility of utilizing lysozyme conjugates with galactomannan or palmitic acid as a therapeutic for infection in fish.
Animals↗