Showing papers by "Hokkaido University published in 1989"
1,357 citations
TL;DR: In axial rotation of the whole lumbar spine, least motion took place at L5-S1 and biggest motion took Place at L2-3, while similar magnitudes of motion were seen at L3-4, L4-5, and L5 -S1.
Abstract: Knowledge of the normal movements of whole lumbar spine and lumbosacral joint is important for evaluating clinical pathologic conditions that may potentially produce unstable situations in these regions. At present there are few studies that report systemic three-dimensional movement analysis of these regions. The purpose of this in vitro study was to quantitatively determine three-dimensional movements of the whole lumbar spine and lumbosacral joint. Ten fresh human cadaveric spine specimens including from L1 to sacrum (six specimens) and ilium (four specimens) were studied. Pure moments of a maximum of 10 N-m were applied incrementally. Parameters of neutral zone, elastic zone, and range of motion for rotations as well as for translations were measured. Neutral zones for flexion-extension, right/left axial torque, and right-left lateral bending were, respectively: 1.6 degrees, 0.9 degrees, and 1.4 degrees (L1-2); 1.0 degrees, 0.8 degrees, and 2.0 degrees (L2-3); 1.4 degrees, 0.7 degrees, and 1.4 degrees (L3-4); 1.8 degrees, 0.4 degrees, and 1.6 degrees (L4-5); 3.0 degrees, 0.4 degrees, and 1.8 degrees (L5-S1). Ranges of motion for flexion, extension, axial torque (one side), and lateral bending (one side) were, respectively: 5.8 degrees, 4.3 degrees, 2.3 degrees, and 4.9 degrees (L1-2); 6.5 degrees, 4.3 degrees, 2.6 degrees, and 7.0 degrees (L2-3); 7.5 degrees, 3.7 degrees, 2.6 degrees, and 5.7 degrees (L3-4); 8.9 degrees, 5.8 degrees, 2.2 degrees, and 5.7 degrees (L4-5); 10.0 degrees, 7.8 degrees, 1.4 degrees, and 5.5 degrees (L5-S1). Neutral zone values were small except for flexion at L5-S1.(ABSTRACT TRUNCATED AT 250 WORDS)
511 citations
TL;DR: Physical characteristics seemingly governed by the topo logical bonding structure, which involves a hierarchy of correlation ranges, from short to medium are discussed.
Abstract: The composition dependence of the structural and electronic properties in chalcogenide glasses suggests that there exists a structural phase transition at the average coordination number of 2.67. Materials having smaller coordination numbers are characterized by molecular structures, and otherwise three-dimensional networks govern the properties. The result is discussed in light of topological and percolative arguments.
493 citations
312 citations
TL;DR: In this article, the authors introduce the notion of Doubly Stochastic Matrices (DSM) and compare its properties with those of other matrices with minimum permanent and double sub-and superstochasticity.
303 citations
TL;DR: It is concluded that the 73-kDa protein in vacuolar membrane functions as an H+-translocating inorganic pyrophosphatase that is strongly inhibited by ATP, GTP, and CTP and reversed by increasing the Mg2+ concentration.
262 citations
TL;DR: The metabolism of glutathione and activities of its related enzymes were studied in erythrocytes from patients with non-insulin-dependent diabetes mellitus to suggest that the impairment ofglutamylcysteine synthetase weakens the defense mechanism against oxidative stress in ERY Throatcytes of diabetics.
Abstract: The metabolism of glutathione and activities of its related enzymes were studied in erythrocytes from patients with non-insulin-dependent diabetes mellitus (NIDDM). A decrease in the levels of the reduced form of glutathione and an increase in the levels of glutathione disulfide were found in erythrocytes of diabetics. To elucidate these changes in the levels of glutathione, synthetic and degradative processes were studied. The activity of gamma-glutamylcysteine synthetase was significantly lower in diabetics than in normal controls. The activity of glutathione synthetase of each group was the same. The rate of outward transport of glutathione disulfide in diabetics decreased to approximately 70% of that of normal controls. The activity of glutathione reductase decreased in diabetics. These data suggest that the decrease in the levels of reduced form of glutathione in erythrocytes of diabetics is brought about by impaired glutathione synthesis and that the increase in the levels of glutathione disulfide is brought about by the decreased transport activity of glutathione disulfide through the erythrocyte membrane together with a decrease in the activity of glutathione reductase. These data also suggest that the impairment of glutathione metabolism weakens the defense mechanism against oxidative stress in erythrocytes of diabetics.
248 citations
TL;DR: For example, this article found that Chinese and American subjects indicated degrees of certainty about their answers to general knowledge questions with discrete alternatives, e.g., whether potatoes grow better in warm or in cool climates.
217 citations
212 citations
TL;DR: In this article, a review is given of some simplified concepts that will contribute to a better understanding of corrosion fundamentals and the corrosion process involves not only electrochemical reactions but also chemical reactions.
Abstract: A review is given of some simplified concepts that will contribute to a better understanding of corrosion fundamentals. The corrosion process involves not only electrochemical reactions bu...
202 citations
TL;DR: In this paper, an insulin receptor complementary DNA has been cloned from an insulin-resistant individual whose receptors have impaired tyrosine protein kinase activity, where valine is substituted for Gly996, the third glycine in the conserved Gly-X-Gly -X-X -Gly motif in the putative binding site fo adenosine triphosphate.
Abstract: Insulin receptor complementary DNA has been cloned from an insulin-resistant individual whose receptors have impaired tyrosine protein kinase activity. One of this individual's alleles has a mutation in which valine is substituted for Gly996, the third glycine in the conserved Gly-X-Gly-X-X-Gly motif in the putative binding site fo adenosine triphosphate. Expression of the mutant receptor by transfection into Chinese hamster ovary cells confirmed that the mutation impairs tyrosine kinase activity.
TL;DR: In this paper, the structure of a Tuber-inducing Stimulus from Potato Leaves (Solanum tuberosum L.) is described. But the structure is not described in detail.
Abstract: (1989). Structure of a Tuber-inducing Stimulus from Potato Leaves (Solanum tuberosum L.) Agricultural and Biological Chemistry: Vol. 53, No. 10, pp. 2835-2837.
TL;DR: The process of sex change from ovary to testis was divided into six stages on the basis of changes in the structure of the germinal and somatic elements, and sex change to male was considered complete with the beginning of active spermatogenesis and spermiation.
Abstract: The process of sex change in the protogynous wrasse, Thalassoma duperrey, was investigated through histological and ultrastructural observations on the gonads of females changing sex to male. Changes in plasma steroid levels concomitant with structural changes were measured by radioimmunoassay. The process of sex change from ovary to testis was divided into six stages on the basis of changes in the structure of the germinal and somatic elements. Ovaries of females were filled with vitellogenic oocytes during the breeding season, but contained no spermatogenic tissue (Stage 1). At the commencement of sex change (Stage 2), vitellogenic oocytes began to degenerate, and were ingested by macrophagous cells. This stage was accompanied by a rapid drop in plasma levels of estradiol-17β. Thereafter, previtellogenic oocytes (Stage 3) also began to degenerate, and aggregations of stromal tissue, and loose connective tissue were observed in the central region of the lamellae. Steroid producing cells (Leydig cells), developed at the border of this loose connective tissue. Presumed spermatogonia proliferated on the periphery of the lamellae, and Leydig cells increased in size and number (Stage 4). Spermatogonia formed cysts, and underwent spermatogenesis (Stage 5). Finally, sex change to male was considered complete, with the beginning of active spermatogenesis and spermiation (Stage 6). Plasma levels of testosterone remained low throughout the sex change, but a second androgen, 11-ketotestosterone increased gradually in parallel to the increased numbers of Leydig cells and spermatogonia. Preliminary in vitro incubation of gonads with salmon gonadotropin, revealed that sex-changed males had higher levels of 11-ketotestosterone production than did females, while females had higher levels of estradiol-17β production than did males. Production of both these steroids increased in a dose-related fashion with increasing doses of gonadotropin.
TL;DR: It was demonstrated that the slope of the plots should be approximately proportional to a change in accessible surface area of the protein during the respective activation process, and that only a third of the difference inaccessible surface area between A and N is buried in the critical activated state of folding.
TL;DR: Nucleotide sequences of the first and second internal transcribed spacers (ITS1 and ITS2) of ribosomal DNA (rDNA) from two dicot plants, carrot and broad bean, were determined and showed a wide range of variation in their G+C content, in contrast to a general trend toward very high G-C content in animals.
Abstract: Nucleotide sequences of the first and second internal transcribed spacers (ITS1 and ITS2, respectively) of ribosomal DNA (rDNA) from two dicot plants, carrot and broad bean, were determined. These sequences were compared with those of rice, a monocot plant, and other eukaryotic organisms. Both types of ITS region in some species of Angiospermae were the shortest among all eukaryotes so far examined and showed a wide range of variation in their G+C content, in contrast to a general trend toward very high G+C content in animals. Phylogenetic relationships of plants with animals and lower eukaryotes were considered using the nucleotide sequences of carrot and broad bean 5.8S rDNA that were determined in the present study, together with that of wheat 5.8S rRNA, which has been reported previously.
TL;DR: The antibiotics produced by Pseudomonas cepacia strain RB425, obtained from a lettuce root and active as a biological control agent against several soilborne plant pathogens, showed high activity against several species of fungal pathogens including Pyricularia oryzae as well as R. solani and V. dahliae.
Abstract: Antibiotics produced by Pseudomonas cepacia strain RB425 obtained from a lettuce root and active as a biological control agent against several soilborne plant pathogens, were studied to determine the mechanism of disease suppression by this strain. Cultures of RB425 were extracted with chloroform or ethyl acetate and the antibiotics isolated in the pure or semi-pure form by silica gel column chromatography, gel filtration and high performance liquid chromatography. The active fractions were detected by bioautography on TLC plates using Rhizoctonia solani and Venicillium dahliae as sensitive indicators of antibiotic activity following each fractionation. On the basis of u.V., i.r., NMR and mass spectra, the antibiotics were shown to be similar or identical to pyrrolnitrin and two kinds of pseudane, 2-(2-heptenyl)-3-methyl-4-quinolinol and 2-(2-nonenyl)-3-methyl-4-quinoIinol. The antibiotics showed high activity against several species of fungal pathogens including Pyricularia oryzae as well as R. solani and V. dahliae, but relatively less antibacterial activity. These substances may be involved in disease suppression by P. cepacia RB425.
TL;DR: The structure and function of transcription factors of higher plants was studied by isolating cDNA clones encoding a wheat sequence-specific DNA binding protein, which indicates that HBP-1 contains the leucine zipper motif, which represents a characteristic property of several eukaryotic transcription factors.
Abstract: The structure and function of transcription factors of higher plants was studied by isolating cDNA clones encoding a wheat sequence-specific DNA binding protein. A hexameric nucleotide motif, ACGTCA, is located upstream from the TATA box of several plant histone genes. It has been suggested that this motif is essential for efficient transcription of the wheat histone H3 gene. A wheat nuclear protein, HBP-1 (histone DNA binding protein-1), which specifically binds to the hexameric motif, has previously been identified as a putative transcription factor. A cDNA clone encoding HBP-1 has been isolated on the basis of specific binding of HBP-1 to the hexameric motif. The deduced amino acid sequence indicates that HBP-1 contains the leucine zipper motif, which represents a characteristic property of several eukaryotic transcription factors.
TL;DR: Since micronuclei were more efficiently induced in these hybrids compared to parental human fibroblasts by colcemid treatment, the transfer of neo‐tagged human chromosomes in the hybrids was performed via microcell fusion.
Abstract: Normal human fibroblasts (MRC-5 or NTI-4) were transfected with pSV2-neo plasmid DNA. Fifty G418-resistant fibroblast clones were isolated and independently fused to mouse A9 cells. The cell hybrids were selected and isolated in the medium containing G418 plus ouabain. Since micronuclei were more efficiently induced in these hybrids compared to parental human fibroblasts by colcemid treatment, the transfer of neo-tagged human chromosomes in the hybrids to mouse A9 cells was performed via microcell fusion. Two hundred A9 microcell hybrids were isolated and karyotyped. Among them, thirteen microcell clones, each containing a single human chromosome 1, 2, 5, 6, 7, 8, 10, 11, 12, 15, 18, 19 or 20 were established. Isozyme analyses conformed the presence of each human chromosome in these A9 microcell clones. The results of Southern blot and chromosomal in situ hybridization analyses indicate that the human chromosomes in these clones were tagged with pSV2-neo plasmid DNA.
TL;DR: P400 protein is a Purkinje cell-characteristic plasma membrane-associated glycoprotein, which is also present at the postsynaptic density and endoplasmic reticulum and that the expression of P400 protein in Purkinja cells is closely associated with the growth of their dendritic arborization.
TL;DR: From the high‐resolution structure of HU, a model for this interaction with DNA is proposed andcial amino acid differences between the proteins can be rationalized in terms of their different specific functions.
Abstract: The prokaryotic protein HU, integration host factor (IHF) from Escherichia coli, and transcription factor 1 (TF1) from bacteriophage SPO1 are closely related molecules. Biochemical results suggest that the role of these proteins is to bind and bend DNA. From the high-resolution structure of HU, we propose a model for this interaction with DNA. Crucial amino acid differences between the proteins can be rationalized in terms of their different specific functions.
TL;DR: With the DNA binding gel-shift assay, the authors could detect protein(s) that specifically binds to the TRE-like sequence of GPEI fragment, which was possibly c-jun.c-fos complex or a similar protein complex.
Journal Article•
TL;DR: It is found that the polymerization (multivalency) of the Arg-Gly-Asp core sequence was able to augment the inhibition of tumor lung metastases in experimental and spontaneous metastasis models as well as the cell-adhesive property more effectively than a monovalent unit of Arg- Gly- asp peptide.
Abstract: We investigated that the antimetastatic and antiadhesive activities of peptides based on Arg-Gly-Asp adhesive signal in fibronectin could be augmented by their polymerization. Poly(Arg-Gly-Asp), which consists of a repetitive sequence of Arg-Gly-Asp, inhibited lung metastases in C57BL/6 mice more effectively than Arg-Gly-Asp tripeptide was able to do, when coinjected or separately injected with B16-BL6 cells. The adhesion of tumor cells to fibronectin was specifically inhibited by adding poly(Arg-Gly-Asp) but not unrelated peptides. In contrast, poly(Arg, Gly, Asp), in which three amino acids are randomly arranged, showed neither inhibition of lung metastases nor any adhesive ability to attach to tumor cells. The inhibitory effect of polymeric peptides containing the Arg-Gly-Asp sequence on lung metastases decreased according to the decreasing repeat units of the Arg-Gly-Asp core sequence. Polymeric peptides with Arg-Gly-Asp entrapped within the liposome membranes also caused a remarkable reduction of metastatic colonies. In a spontaneous metastasis model, multiple i.v. administrations of poly(Arg-Gly-Asp) after tumor inoculation caused the significant reduction of metastatic colonies in the lung but did not affect the growth (size) of primary tumor. We found that the polymerization (multivalency) of the Arg-Gly-Asp core sequence was able to augment the inhibition of tumor lung metastases in experimental and spontaneous metastasis models as well as the cell-adhesive property more effectively than a monovalent unit of Arg-Gly-Asp peptide.
TL;DR: The number of agonistic encounters in a group and the mean distance to the nearest neighbor in agroup were analyzed by a multiple regression on the group size and space allowance in each group of calves and adult cattle.
TL;DR: The ribozyme was shown to distinguish a single base mutation in mRNA's which were prepared by transcription of two synthetic DNA duplexes coding for positions 7-26 of c-Ha-ras protein.
Abstract: RNA enzymes (ribozymes) which can cleave RNA by recognizing sequences of 9-15 bases are described. Substrates must contain UX (X = U, C or A). A ribozyme consisting of two oligoribonucleotides (19 mer and 15 mer) was shown to cleave a ribo 11 mer catalytically with Km and kcat values of 0.53 microM and 0.03 min-1, respectively. A non-cleavable substrate-ribozyme complex containing 2'-O-methylnucleoside was prepared and CD spectra were compared at different temperature. In order to obtain an efficient ribozyme, a one-strand RNA with a chain length of 37 was prepared. The ribozyme was shown to distinguish a single base mutation in mRNA's which were prepared by transcription of two synthetic DNA duplexes coding for positions 7-26 of c-Ha-ras protein. The mutant (Val-12) mRNA which had GUU was cleaved but the wild type mRNA which contained GGU was not changed, when treated by the ribozymes in the presence of Mg2+.
TL;DR: From the analysis of phylogenetic trees constructed from the amino acid sequences and metal-binding properties of various lysozymes c and alpha-lactalbumins, it was found that before the divergence of the lineages of birds and mammals, calcium-binding lysozyme diverged from non-calcium-binding Lysozyme.
Abstract: From the analysis of phylogenetic trees constructed from the amino acid sequences and metal-binding properties of various lysozymes c and α-lactalbumins, it was found that before the divergence of the lineages of birds and mammals, calcium-binding lysozyme diverged from non-calcium-binding lysozyme α-Lactalbumin evolved from the calcium-binding lysozyme along the mammalian lineage after the divergence of birds and mammals Rapid evolution took place, not in the process of acquisition of the activity of α-lactalbumin, but after the loss of lysozyme activity, due to the change in the distribution of selective pressure on each amino acid site
A general process for the change in function of a protein during evolution is suggested to be as follows: after duplication of the gene, one of their protein products acquires a new function, besides that already present; the old function is eventually lost
01 Jan 1989
Abstract: In an abstract framework, we present a class of supersymmetric quantum mechanics whose eigenvalue problem is (in part) exactly solvable. In concrete realizations, the class includes supersymmetric quantum mechanical models associated with one-dimensional or radial Schrodinger operators with potentials of a special type, called “shape-invariant potentials” in the physics literature.
TL;DR: The events of stage 1 suggest the in- volvement of a male- produced pheromone causing the recognition of males by the females, while the events of stages 2 and 3 indicate the utilization of a female-produced phersomone which elicits mating activity in the males.
Abstract: the latter will be aroused and will mount the female laterally. Stage 3: subsequently, the male settles on the female's dorsum in a parallel position for a period of 0.5 - 1.0 min, while the female (with the male on her dorsum) will commence walking. Stage 4: the male turns his body by ~ 180 ~ and transfers his gnathosoma and part of his idiosoma beyond the margin of the female's opisthosoma. The male will then attach himself to the latter by his anal and tarsal suckers. In this position both sexes remain linked for 128- 219 min, during which the aedeagus is in- serted to the bursa copulatrix. Copu- latory movements are usually per- formed for an average period of 30 min. Insemination involves the produc- tion and transfer of spermatophores to the receptaculum seminis of the female; this process has been described in detail [4,5]. The events of stage 1 suggest the in- volvement of a male-produced pher- omone causing the recognition of males by the females, while the events of stages 2 and 3 indicate the utilization of a female-produced pheromone which elicits mating activity in the males. The use of sex pheromones for mate finding appears particularly important for A. siro, as this species lacks the capability of visual perception. The above results were corroborated by the observed attractiveness of an ex- tract of male A. siro for conspecific females as well as the sexual stimula- tion of male flour mites by an extract of female A. siro. Figure la reveals that
Journal Article•
01 Jan 1989-Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering
TL;DR: Three-dimensional movement of teeth, including rotational movement, during orthodontic treatment, has been quantified by means of the superimposition of tooth profiles using a computer.
Abstract: Dental casts are frequently used for measuring the size, shape and position of a tooth. We have developed an optical apparatus for measuring a three-dimensional profile of a dental cast. The measurement is based on the triangular method which detects a laser spot on a cast by an image sensor. The apparatus is computer-controlled and designed to achieve a total measuring depth of 40 mm, a data acquisition time of 25 ms per point and a minimum scanning pitch of 0.1 mm. The depth and lateral resolutions are 0.05 and 0.1 mm, respectively, within a depth range of 25 mm. As a particular application of the apparatus, three-dimensional movement of teeth, including rotational movement, during orthodontic treatment, has been quantified by means of the superimposition of tooth profiles using a computer.
TL;DR: In this article, drastic anomalies have been found below ∼ 60K in a narrow Ba concentration region around x=0.12, where the superconducting transition temperature is reported by Moodenbaugh et al. to have a significant dip as a function of x.