Showing papers by "Hokkaido University published in 1990"
TL;DR: An A-to-G transition mutation at nucleotide pair 3,243 in the dihydrouridine loop of mitochondrial tRNALeu(UUR) that is specific to patients with MELAS is reported, which creates an Apal restriction site and could perform a simple molecular diagnostic test for the disease.
Abstract: MITOCHONDRIAL encephalomyopathies are usually divided into three distinct clinical subgroups: (1) mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS); (2) myoclonus epilepsy associated with ragged-red fibres (MERRF); and (3) chronic progressive external ophthalmoplegia (CPEO) including Kearns-Sayre syndrome1–5. Large deletions of human mitochondrial DNA and a transition mutation at the mitochondrial transfer RNAlys gene give rise to CPEO including Kearns–Sayre syndrome6–8 and MERRF9,10, respectively. Here we report an A-to-G transition mutation at nucleotide pair 3,243 in the dihydrouridine loop of mitochondrial tRNALeu(UUR) that is specific to patients with MELAS. Because this mutation creates an Apal restriction site, we could perform a simple molecular diagnostic test for the disease. The mutation was present in 26 out of 31 independent MELAS patients and 1 out of 29 CPEO patients, but absent in the 5 MERRF and 50 controls tested. Southern blot analysis confirmed that the mutant DNA always coexists with the wild-type DNA (heteroplasmy).
1,896 citations
TL;DR: Findings suggest that lethal midline granuloma is causally associated with Epstein-Barr virus.
533 citations
TL;DR: Pigeon pea was shown to be more efficient at utilizing iron-bound phosphorus than several other crop species, and this finding suggests that cultivation of pigeon pea increases total phosphorus availability in cropping systems with low available phosphorus.
Abstract: Pigeon pea was shown to be more efficient at utilizing iron-bound phosphorus (Fe-P) than several other crop species. This ability is attributed to root exudates, in particular piscidic acid and its p-O-methyl derivative, which release phosphorus from Fe-P by chelating Fe3+. Pigeon pea is normally intercropped with cereals under low-input conditions in the Indian subcontinent. Although pigeon pea can utilize the relatively insoluble Fe-P, intercropped cereals must rely on the more soluble calcium-bound phosphorus. This finding suggests that cultivation of pigeon pea increases total phosphorus availability in cropping systems with low available phosphorus.
519 citations
TL;DR: It is suggested that medial facetectomy does not affect lumbar spinal stability, and conversely, total facetectomy, even created unilaterally, makes the lumbr spine unstable.
Abstract: In an in vitro experiment using fresh human lumbar functional spinal units, the effects of the division of the posterior ligaments (consisting of the supraspinous/ interspinous ligaments) and graded facetectomies were investigated. The graded facetectomies consisted of unilateral and bilateral media
466 citations
TL;DR: The recent literature on solid superacid catalysts is reviewed in this article, where three types of solid super acid have been developed: (i) amounted acid, which was obtained by the fixation of a liquid acid such as SbF 5 on supports of high surface area, (ii) combined acid, obtained by combining of metal halides with metalsalts, and (iii) sulfate-promoted metal oxides.
402 citations
TL;DR: Molecular cloning of human and mouse XPAC complementary DNAs indicates that a defective XPAC gene causes group A XP, and expresses ultraviolet-resistance on several group A cell lines, but not on lines of other XP groups.
Abstract: Xeroderma pigmentosum (XP) is an autosomal recessive disease, characterized by a high incidence of sunlight-induced skin cancer. Cells from people with this condition are hypersensitive to ultraviolet because of a defect in DNA repair. There are nine genetic complementation groups of XP, groups A-H and a variant. We have cloned the mouse DNA repair gene that complements the defect of group A, the XPAC gene. Here we report molecular cloning of human and mouse XPAC complementary DNAs. Expression of XPAC cDNA confers ultraviolet-resistance on several group A cell lines, but not on lines of other XP groups. Almost all group A lines tested showed abnormality or absence of XPAC messenger RNAs. These results indicate that a defective XPAC gene causes group A XP. The human and mouse XPAC genes are located on chromosome 9q34.1 and chromosome 4C2, respectively. Human XPAC cDNA encodes a protein of 273 amino acids with a zinc-finger motif.
364 citations
252 citations
TL;DR: In this paper, the monthly mean chemical composition of aerosol with diameter less than 8 μm was identified in Sapporo in 1982 and nine components were identified: elemental C, organics, SO42−, NO3−, NH4+, Cl−, Na+, soil particles and water.
240 citations
TL;DR: Results indicate that P- 450(HFL33) is expressed specifically in fetal livers and that neither P-450NF nor HLp is expressed in fetalLivers, but one or both are expressed in adult livers.
Abstract: The developmentally regulated expression of forms of cytochrome P-450, namely, those encoded by lambda HFL33 and NF25 or HLp cDNAs, which were isolated from respective fetal and adult human liver cDNA libraries, was investigated. When EcoRI fragments of cDNA clones of lambda HFL33 and NF25 were used as probes, these probes hybridized with RNA from both fetal and adult human livers. However, when oligonucleotides specific to the coding and 3'-noncoding region of lambda HFL33 (oli-HFL and oli-HFL3', respectively) were used as probes, these probes gave hybridizable bands with RNA from fetal but not adult livers. On the other hand, an oligonucleotide probe specific to the coding region of NF25 and HLp (oli-NF) gave positive bands with RNA only from adult livers. These results indicate that P-450(HFL33) is expressed specifically in fetal livers and that neither P-450NF nor HLp is expressed in fetal livers, but one or both are expressed in adult livers.
239 citations
TL;DR: In this article, a review is made of essential subjects on the passivtion process, the passive film, and the film breakdown, which is followed either by repassivation or by pitting corrosion depending on the degree of metal salt enrichment at the break sites.
222 citations
TL;DR: In this article, the formulation of dispersive characteristics associated with an electronic polarization is discussed, which is appropriate for use in the finite-difference-time-domain (FD-TD) method and is based on the equation of polarization.
Abstract: In this article, the formulation of dispersive characteristics associated with an electronic polarization is discussed. The formulation is appropriate for use in the finite-difference-time-domain (FD-TD) method and is based on the equation of polarization. The validity of the formulation is verified by comparing the calculated complex dielectric constant with analytical values.
TL;DR: The hypothesis that ketamine might exert its anesthetic effect by a pharmacologically specific interaction with the NMDA receptor is supported.
Abstract: Synaptic mechanisms underlying ketamine anesthesia were studied using in vitro preparations of the lamprey CNS. Although lampreys are one of the most primitive vertebrates, the synaptic physiology and pharmacology are similar to those in the higher vertebrates. Axonal conduction, transmitter release from the presynaptic terminal, postsynaptic response to the putative neurotransmitters, and resting and activated membrane properties were studied in the absence and the presence of various concentrations of ketamine. Ketamine markedly reduced N-methyl-D-aspartate (NMDA)-activated responses, such as depolarizations to bath-applied NMDA and bursting rhythm during "fictive locomotion." The 50% block of the responses took place in the presence of 10-20 microM ketamine, whereas those induced by kainate and quisqualate (the other two subclasses of L-glutamate/L-aspartate agonists) were spared at concentrations higher than 600-800 microM. None of the other neuronal events tested were suppressed in the presence of still higher concentrations of ketamine. The results support the hypothesis that ketamine might exert its anesthetic effect by a pharmacologically specific interaction with the NMDA receptor.
TL;DR: In this paper, the authors describe a polymerization of chlorophenylacetylene initiated by [Rh(norbornadiene)Cl] 2 -Triethylamine Catalyst Containing Long-Lived Propagation Species.
Abstract: Polymerization of m -Chlorophenylacetylene Initiated by [Rh(norbornadiene)Cl] 2 -Triethylamine Catalyst Containing Long-Lived Propagation Species
TL;DR: The highest lysozyme susceptibility was shown by the DAC of around 70% deacetylation which have already been reported to have the highest immunoadjuvant activity through mouse peritoneal macrophage activation.
TL;DR: In this article, it was concluded that copper-ammine complexes held on the surface of the zirconia support exist in three different states, viz., isolated and clustered copper(II) ions and tetraamminecopper (II) nitrate.
TL;DR: Oligonucleotide probes were synthesized and used to screen a human placenta cDNA library and revealed that GSHPx consisted of a 678-base pair open reading frame coding for a 226-amino acid polypeptide with a Mr of 25,389.
Abstract: Human plasma glutathione peroxidase (GSHPx) has been shown to be a selenium-containing enzyme immunologically distinct from cellular GSHPx. Oligonucleotide probes, based on the partial amino acid sequence of plasma GSHPx, were synthesized and used to screen a human placenta cDNA library. Nucleotide sequence analysis of the obtained clones revealed that GSHPx consisted of a 678-base pair open reading frame coding for a 226-amino acid polypeptide with a Mr of 25,389. About 50% of the deduced amino acid sequence was confirmed by partial amino acid sequencing of the peptides in a lysine endopeptidase-digest of the purified enzyme. The amino acid sequence exhibited only 44% homology with that of human cellular GSHPx. Northern blot analysis revealed a single transcript of 2.2 kilobases in the poly(A)+ RNA fractions of human placenta and HepG2 (a human hepatic cell line), but not that of human liver and endothelial cells.
TL;DR: The results indicate that the antisaccade abnormalities in schizophrenics were not correlated with age, duration of illness, length of education, quantity of medication, or acute symptoms such as delusions and hallucinations.
TL;DR: This case is the first report of meningo‐encephalitis associated with HHV‐6 infection associated with exanthem subitum, and it is reported that human herpesvirus‐6 is the causative agent.
Abstract: . We report a 10-month-old boy with acute meningo-encephalitis associated with exanthem subitum. It has recently been reported that human herpesvirus-6 is the causative agent of exanthem subitum, and to our knowledge our case is the first report of meningo-encephalitis associated with HHV-6 infection.
TL;DR: The results suggest that many schizophrenics have difficulty suppressing reflexive saccades and initiating and executing appropriate volitional saccading when the goal for the movements is known but not visible.
TL;DR: In this article, the effect of ultraviolet radiation on ice was studied using electron diffraction to follow the structural changes that take place, and it was shown that, below 70 K, ultraviolet irradiation transforms cubic ice (ice Ic) into amorphous ice (a-H2O).
Abstract: DESPITE current interest1–8 in the effects of ultraviolet radiation and high-energy particles on interstellar ice and on solid mixtures of H2O and other molecules, most attention has so far been paid to the initiation of chemical reactions, although it has been recognized that electron-beam bombardment will convert ice crystals to the amorphous form7,8. Accordingly, we have studied the effect of ultraviolet radiation on ice, using electron diffraction to follow the structural changes that take place. We find that, below 70 K, ultraviolet irradiation transforms cubic ice (ice Ic) into amorphous ice (a-H2O). This is a novel means of forming a-H2O, supplementing previously known routes8–14. We infer that other high-energy rays or particles will amorphize ice crystals below 70 K. We conclude that crystalline ice in stellar atmospheres and on asteroids and planetary satellites will be rendered amorphous by ultraviolet radiation in times short compared with the rimescale of stellar evolution.
01 Nov 1990
TL;DR: Measurements of dental cast profiles revealed that the difference in movements due to orthodontic treatments can be neutralised, and a feasible a pplication of this apparatus to the measurement of a contacting area of occlusal surface is discussed.
Abstract: A computer-controlled apparatus for measuring dental cast profiles h as b een developed. T his apparatus has been applied to the measurement of three-dimensiona l tooth m ovement during orthodontic treatments. T he 3-D movements, including rotations, have been obtained by computer-aided 3-D registration b etween tooth profiles of casts serially taken at different stages of the t reatment. Measurements o ver periods of 70 to 190 days on patients h ave revealed that w e can q uantify the difference in movements due to orthodontic t herapeutics. A feasible a pplication of this t echnique to the measurement of a contacting area of occlusal surface is discussed as well.
TL;DR: In this article, the authors reviewed and discussed data and information on the thermophysical properties of ice, snow, and sea ice, including thermal conductivity, specific heat, density, thermal diffusivity, latent heat of fusion, thermal expansion, and absorption coefficient.
Abstract: The paper reviews and discusses data and information on the thermophysical properties of ice, snow, and sea ice. These properties include thermal conductivity, specific heat, density, thermal diffusivity, latent heat of fusion, thermal expansion, and absorption coefficient. The available data are shown graphically for convenience in conjunction with the recommended correlation equations.
TL;DR: Inspection of the disulfide bond geometry based on the refined X-ray coordinates of baboon alpha-lactalbumin and comparison of the geometry with those in five other proteins clearly demonstrate that the superreactivity arises from the geometric strain imposed on this disulfides bond by the native structure folding.
Abstract: Kinetics of disulfide reduction in {alpha}-lactalbumin by dithiothreitol are investigated by measuring time-dependent changes in absorption at 310 nm and in CD ellipticity at 270 nm. When the disulfide-inact protein is folded, the kinetics are biphasic. The disulfide bond between the half-cystines-6 and -120 is reduced in the fast phase, and the other three disulfide bonds are reduced in the slow phase. The apparent rate constants of the two phases are both proportional to the concentration of dithiothreitol, indicating that both phases are expressed by bimolecular reactions. However, detailed molecular mechanisms that determine the reaction rates are markedly different between the two phases. The slow phase shows a sigmoidal increase in the reaction rate with increasing concentration of a denaturant, urea, and is also accelerated by destabilization of the native state on removal of the bound Ca{sup 2+} ion in the protein. The fast phase reaction rate is, however, decreased with an increase in the concentration of urea, and the disulfide bond shows extraordinary superreactivity in native conditions. Inspection of the disulfide bond geometry based on the refined X-ray coordinates of baboon {alpha}-lactalbumin and comparison of the geometry with those in five other proteins clearly demonstrate that the superreactivity arisesmore » from the geometric strain imposed on this disulfide bond by the native structure folding. Relationships of the disulfide strain energy to the protein stability and the disulfide reactivity are discussed.« less
TL;DR: The concentrations of Cd and Hg reported here, however, seem to be natural rather than due to environmental pollution.
Abstract: Concentrations of four essential elements (Fe, Mn, Zn, and Cu) and two toxic metals (Cd and Hg) were measured in selected tissues of 19 pelagic seabird species collected in the North Pacific and neighboring waters. Essential metal concentrations were generally highest in the liver and less variable than toxic metals among species and also within each species. Fe concentrations in the muscle were higher in Alcidae than in the other families, whereas the opposite trend was found for Fe and Mn in the liver. Zn concentrations varied among species, depending on the Cd concentrations. On the other hand, toxic metal concentrations were highest in the liver or kidney and varied widely among species, greatly depending on differences in the diet among species. Extraordinarily high Hg concentrations were found in Black-footed Albatrosses,Diomedea nigripes, exceeding 300 μg/g wet weight in some, and seemed to be due to constraints on the elimination of Hg. Also, some geographical differences in Cd and Hg concentrations of the seabirds were observed. The concentrations of Cd and Hg reported here, however, seem to be natural rather than due to environmental pollution.
TL;DR: The occurrence of hepatoid adenocarcinoma in both the stomach and the lung suggests that this neoplasm may also be seen in other organs of endodermal origin, and may be a major histological subtype of AFP-producing endoder mal neoplasms of non-germ cell origin.
Abstract: Seven cases of alpha-fetoprotein (AFP)-producing lung carcinoma were studied histologically to determine whether they fell into any previously described category. The patients were all males from 40 to 73 years of age and their serum AFP levels ranged from 1039 to 320000 ng/ml. Five cases of hepatoid adenocarcinoma, one case of endodermal sinus tumour, and one case of papillary adenocarcinoma were found. The possible origins of the tumours and their differential diagnosis are discussed. Hepatoid adenocarcinoma is a major histological category among AFP-producing lung carcinoma; other types are less frequent. The occurrence of hepatoid adenocarcinoma in both the stomach and the lung suggests that this neoplasm may also be seen in other organs of endodermal origin. It may be a major histological subtype of AFP-producing endodermal neoplasms of non-germ cell origin.
TL;DR: Two novel antimicrobial tetrapeptide-like substances, halocyamine A and B, were isolated from the solitary ascidian Halocynthia roretzi by a procedure including extraction steps, chromatographies on coarse and fine HP-20 columns, and preparative reversed-phase high-performance liquid chromatography.
Abstract: Two novel antimicrobial tetrapeptide-like substances, halocyamine A and B, were isolated from the solitary ascidian Halocynthia roretzi by a procedure including extraction steps, chromatographies on coarse and fine HP-20 columns, and preparative reversed-phase high-performance liquid chromatography. The structures of halocyamine A and B were determined to be L-histidyl-L-6,7-dihydroxyphenylalanylglycyl-6-bromo-8,9-didehy drotryptamine and L-threonyl-L-6,7-dihydroxyphenylalanyl-L-histidyl-6-bromo-8,9- didehydrotryptamine, respectively, by spectral analyses and degradation studies. Besides antimicrobial activities against several kinds of bacteria and yeasts, both of them showed cytotoxic activities against neuronal cells cultured from rat fetal brain, mouse neuroblastoma N-18 cells, and human hepatoma Hep-G2 cells. They were only detected in the "morula"-like cells, which are of the most abundant cell type among the hemocytes of H. roretzi.
TL;DR: Macrolactonization of 3,5- O -(3,4-dimethoxybenzylidene)-9,11-O -(2,4,6-trimethylbenzo-idene)(9 S )-9-dihydroerythronolide A seco-acid (4 ) was reexamined under various conditions and found to proceed rapidly only by treatment of 4 with Yamaguchi's reagent, 2.4, 6-trichlorobenzoyl chloride, in the presence
TL;DR: It appears that GVHR occurring in the thymus at an early stage abrogates thymic stromal functions essential to induction of self-tolerance in the T-cell repertoire.
Abstract: Graft-versus-host reaction (GVHR) following allogeneic bone marrow (BM) transplantation was investigated by analyzing expression of antigen receptors on T cells specific for recipient antigens. GVHR chimeras were prepared by transplanting mixtures of splenic T cells and T-cell-depleted BM cells from B10 (I-E-, Mls-1b) or B10.AQR (I-E+, Mls-1b) mice into lethally irradiated AKR/J (I-E+, Mls-1a) recipients. Increased proportions of V beta 6+ T cells reactive to recipient antigens (I-E and Mls-1a) were observed in thymuses from such chimeras 1 or 5 wk after BM transplantation. V beta 6+ T cells observed 1 wk after BM transplantation were derived from mature T cells that had been inoculated into recipients. These cells responded to recipient antigens expressed in the thymus. After 5 wk, thymocytes brightly positive for V beta 6+ were shown not to descend from mature T cells but to differentiate from precursor cells present in the BM inocula. Since V beta 6+ T cells were eliminated in thymuses from non-GVHR chimeras 5 wk after BM transplantation using T-cell-depleted BM cells alone, it appears that GVHR occurring in the thymus at an early stage abrogates thymic stromal functions essential to induction of self-tolerance in the T-cell repertoire. These findings propose a mechanism (autoimmunity) to explain in part the pathogenesis of chronic GVHR.
TL;DR: In this paper, it was shown that if a weak Navier-Stokes solution is in some Lebesgue space or small in some Lorentz space locally, it does not blowup there.
Abstract: We are concerned with the behavior of weak solutions of the Navier-Stokes equations near possible singularities. We shall show that if a weak solution is in some Lebesgue space or small in some Lorentz space locally, it does not blowup there. Our basic idea is to estimate integral formulas for vorticity which satisfies parabolic equations.