Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0428
    Keywords: Keywords Insulin receptor substrate-1 (IRS-1) ; non-insulin-dependent diabetes mellitus ; genetics ; single-stranded conformation polymorphisms ; insulin resistance ; polymorphism.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Since the insulin receptor substrate-1 (IRS-1) is the major substrate of the insulin receptor tyrosine kinase and has been shown to activate phosphatidylinositol (PI) 3-kinase and promote GLUT4 translocation, the IRS-1 gene is a potential candidate for development of non-insulin-dependent diabetes mellitus (NIDDM). In this study, we have identified IRS-1 gene polymorphisms, evaluated their frequencies in Japanese subjects, and analysed the contribution of these polymorphisms to the development of NIDDM. The entire coding region of the IRS-1 gene of 94 subjects (47 NIDDM and 47 control subjects) was screened by polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) analysis. Seven SSCP polymorphisms were identified. These corresponded to two previously identified polymorphisms [Gly971→Arg (GGG→AGG) and Ala804 (GCA→GCG)] as well as five novel polymorphisms [Pro190→Arg (CCC→CGC), Met209→Thr (ATG→ACG), Ser809→Phe (TCT→TTT), Leu142 (CTT→CTC), and Gly625 (GGC→GGT)]. Although the prevalence of each of these polymorphisms was not statistically different between NIDDM and control subjects, the prevalence of the four IRS-1 polymorphisms with an amino acid substitution together was significantly higher in NIDDM than in control subjects (23.4 vs 8.5 %, p 〈 0.05), and two substitutions (Met209→Thr and Ser809→Phe) were found only in NIDDM patients. Equilibrium glucose infusion rates during a euglycaemic clamp in NIDDM and control subjects with the IRS-1 polymorphisms decreased by 29.5 and 22.0 %, respectively on the average when compared to those in comparable groups without polymorphisms, although they were not statistically significant. Thus, IRS-1 polymorphisms may contribute in part to the insulin resistance and development of NIDDM in Japanese subjects; however, they do not account for the major part of the decrease in insulin-stimulated glucose uptake which is observed in subjects with clinically apparent NIDDM. [Diabetologia (1996) 39: 600–608]
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0428
    Keywords: Keywords MODY ; hepatocyte nuclear factor-1α ; recombinant adenovirus ; MIN6 cells ; dominant negative effect ; arginine.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Aims/hypothesis. To explain the mechanisms whereby mutations in the HNF-1α gene cause insulin secretory defects. Methods. A truncated mutant HNF-1α (HNF-1α288 t) was overexpressed in hepatoma cells (HepG2) and murine insulinoma cells (MIN6) using a recombinant adenovirus system and expression of the HNF-1α target genes and insulin secretion were examined. Results. Expression of phenylalanine hydroxylase and α1-antitrypsin genes, the target genes of HNF-1α, was suppressed in HepG2 cells by overexpression of HNF-1α288 t. In MIN6 cells, overexpression of HNF-1α288 t did not change insulin secretion stimulated by glucose (5 mmol/l and 25 mmol/l) or leucine (20 mmol/l). Potentiation of insulin secretion by arginine (20 mmol/l, in the presence of 5 mmol/l or 25 mmol/l glucose) was, however, reduced (p 〈 0.0001 and p = 0.027, respectively). Similarly reduced responses were observed when stimulated with homoarginine. Expression of the cationic amino acid transporter-2 was not reduced and insulin secretory response to membrane depolarization by 50 mmol/l KCl was intact. Conclusion/interpretation. The HNF-1α288 t, which is structurally similar to the mutant HNF-1α expressed from the common MODY3 allele, P291fsinsC, exerts a dominant negative effect. Suppression of HNF-1α in MIN6 cells severely impaired potentiation of insulin secretion by arginine, whereas glucose-stimulated and leucine-stimulated insulin secretion was intact. Our findings delineate the complex nature of beta-cell failure in patients with MODY3. This cell model will be useful for further investigation of the mechanism of insulin secretory defects in these patients. [Diabetologia (1999) 42: 887–891]
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0428
    Keywords: Insulin receptor substrate-1 (IRS-1) ; non-insulin-dependent diabetes mellitus ; genetics ; single-stranded conformation polymorphisms ; insulin resistance ; polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Since the insulin receptor substrate-1 (IRS-1) is the major substrate of the insulin receptor tyrosine kinase and has been shown to activate phosphatidylinositol (PI) 3-kinase and promote GLUT4 translocation, the IRS-1 gene is a potential candidate for development of non-insulin-dependent diabetes mellitus (NIDDM). In this study, we have identified IRS-1 gene polymorphisms, evaluated their frequencies in Japanese subjects, and analysed the contribution of these polymorphisms to the development of NIDDM. The entire coding region of the IRS-1 gene of 94 subjects (47 NIDDM and 47 control subjects) was screened by polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) analysis. Seven SSCP polymorphisms were identified. These corresponded to two previously identified polymorphisms [Gly971→Arg (GGG→AGG) and Ala804 (GCA→GCG)] as well as five novel polymorphisms [Pro190→Arg (CCC→CGC), Met209→Thr (ATG→ACG), Ser809→Phe (TCT→TTT), Leu142 (CTT→CTC), and Gly625 (GGC→GGT)]. Although the prevalence of each of these polymorphisms was not statistically different between NIDDM and control subjects, the prevalence of the four IRS-1 polymorphisms with an amino acid substitution together was significantly higher in NIDDM than in control subjects (23.4 vs 8.5%, p〈0.05), and two substitutions (Met209→Thr and Ser809→Phe) were found only in NIDDM patients. Equilibrium glucose infusion rates during a euglycaemic clamp in NIDDM and control subjects with the IRS-1 polymorphisms decreased by 29.5 and 22.0%, respectively on the average when compared to those in comparable groups without polymorphisms, although they were not statistically significant. Thus, IRS-1 polymorphisms may contribute in part to the insulin resistance and development of NIDDM in Japanese subjects; however, they do not account for the major part of the decrease in insulin-stimulated glucose uptake which is observed in subjects with clinically apparent NIDDM.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental pharmacology and physiology 22 (1995), S. 0 
    ISSN: 1440-1681
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: 1. Endothelium-dependent relaxation by a-adrenoceptor agonists was examined in the thoracic aorta from normoten-sive Wistar-Kyoto (WKY) rats and stroke-prone spontaneously hypertensive rats (SHRSP).2. In ring preparations from both strains, noradrenaline-induced contraction was increased by L-nitro arginine (L-NNA), a NO synthesis inhibitor.3. L-NNA increased the contraction induced by phenyl-ephrine, an α1-adrenoceptor agonist. UK-14304 and clonidine, α2-adrenoceptor agonists, did not contract the preparations with intact endothelium. However, these agents contracted preparations when NO synthesis was inhibited.4. In a precontracted preparation, clonidine and UK-14304 induced relaxations. The relaxations in SHRSP aorta were smaller than those in WKY aorta.5. These results indicate that a-agonists release NO from endothelium in WKY and SHRSP aorta. The mechanism related to NO release by α2-adrenoceptor agonist is impaired in SHRSP aorta.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 5261-5263 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Exchange-biased magnetic tunnel junctions with a Ta/NiFe/FeMn/NiFe/Al–oxide/NiFe/Ta structure have been fabricated. The tunnel barrier was formed by the in situ natural oxidation of an Al metal layer under controlled oxygen pressure. Photolithography and ion milling were used to pattern the multilayer into junction structures of 2×2 μm2–20×20 μm2 dimensions. Magnetoresistance (MR) curves show spin-valve-like characteristics, in which an antiparallel configuration of magnetizations in both ferromagnetic layers is observed between 50 and 240 Oe, and the hysteresis loops for both the free and pinned layers exhibit sufficient separation. An evaluation of the MR curves shows the exchange-bias field to be 340 Oe and coercivity levels in the free layer to become as low as 13 Oe. At room temperature normalized junction resistance is 2×10−5 Ω cm2, with MR ratios still being maintained at 13%. This resistance value is much lower than previously reported values for junctions produced either with plasma oxidation or thermal oxidation in air. Maximum variation in junction resistance is only ±5% for 10×10 μm2 junctions over a 2 in. wafer. The MR ratio decreases by half when the bias voltage is raised from 0 to 440 mV, approximately the same ratio of decrease as has been previously reported for other successful junctions. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 5807-5809 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The interface structures of magnetic tunnel junctions were studied using x-ray photoelectron spectroscopy (XPS). The structures were correlated with magnetoresistance (MR) characteristics. For MR measurements, Fe(50 nm)/AlOx/CoFe(30 nm) junctions with an in situ naturally oxidized Al tunnel barrier were fabricated. The thickness of the Al layer, an important parameter in MR characteristics, was varied from 0 to 5 nm. MR curves showed that the largest MR ratio occurred when the Al layers were 2–3 nm in thickness. XPS analysis showed that an Al layer greater than 1 nm thick covers the entire surface of the Fe underlayer. However, if the Al layer is more than 1 nm thick, the unoxidized Al remaining after the oxidation process increases as the thickness is increased. For Al layers that are greater than 3 nm thick, the MR ratio is strongly affected by unoxidized Al, probably due to the decrease in spin polarization at the surface of an Fe/Al electrode. On the other hand, the hysteresis loops indicate that the difference in coercive force between Fe and CoFe layers reduces with decreasing Al thickness for Al layers less than 2.5 nm thick. This means that the antiparallel direction of magnetization in the two layers becomes incomplete due to the gradual increase of the ferromagnetic coupling between them. As a result, the MR ratio decreases, although a 1-nm-thick Al layer seems to be enough to cover the Fe surface. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 2773-2775 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The structure of a near-field probe was optimized for illumination-collection hybrid mode (I–C mode) operation. We developed a highly sensitive probe with a sharp-edged aperture and a double-tapered structure fabricated by a chemical etching technique. Through measurement of the photoluminescence (PL, λ=1 μm) image of single quantum dots, the performance of many versions of the probe with different aperture diameters, ranging from 80 to 500 nm, was systematically evaluated. In addition to the throughput and spatial resolution, the absolute value of the PL collection efficiency of the probe in (I–C mode) was also estimated for the first time. A collection efficiency several times greater than that of an objective lens with a numerical aperture of 0.8 was achieved with high spatial resolution in the 130–200 nm (λ/8–λ/5) range. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Archives of orthopaedic and trauma surgery 119 (1999), S. 380-383 
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although various operative procedures have been applied for advanced or terminal osteoarthritis of the hip joints in relatively young patients, the long-term results are controversial. Since 1974, we have performed the triple-cup arthroplasty developed by Aoki in 110 patients who were comparatively young. The triple-cup assembly is composed of stainless-steel outer and inner cups between which a high density polyethylene cup is incorporated, so that there are basically four mobile surfaces, but the major movement is actually taking place between the outer cup and the plastic cup [8]. We have sometimes encountered migration of the cups, which caused hip joint pain and decreased the range of motion. Revision surgery was required for 25 hip joints in 21 patients (23%). The acetabulum was very thin in almost all cases, so that reaming of the cavity had to be restricted to the minimum possible. The femoral head in the cup was often covered with a layer of fibrous tissue. We could utilize the femoral head as a bone graft, even though the residual volume of bone varied in each case. The result of revision surgeries after the triple-cup arthroplasty was good clinically and radiographically at last follow-up.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 20 (1999), S. 1875-1888 
    ISSN: 1572-9559
    Keywords: submillimeter wave ESR ; gyrotron ; pulse magnet ; ruby (Al2O3:Cr3+)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Fine structure constant of ruby has been measured using an ESR spectrometer with a pulse magnetic for high fields and a gyrotron as a radiation source in a millimeter to submillimeter wave range. The measurement was carried out at room temperature. The Zeeman energy in this frequency range is large enough compared with the fine structure constant. The higher order term in the effective spin Hamiltonian can explain the dependence of fine structure constant on the frequency. The observed fine structure constants depend on the field intensity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The effect of casting and homogenizing treatment conditions on the formation of several Al–Fe–Si intermetallic compounds in 6063 aluminum alloy was investigated using X-ray diffraction and transmission electron microscopy (TEM). The four kinds of alloys containing 0.1 to 0.5 mass% Fe were melted and then cooled at three different cooling rates ranging from 0.06 to 50 K/s, following the homogenization at 858 K for 54 ks and 2400 ks. The Al–Fe–Si compound particles were extracted from the alloy ingots using the thermal phenol method. The as-cast 0.1 mass% Fe ingot obtained at the casting cooling rate of 0.06 K/s had a largest amount of the β phase among the ingots investigated. When this ingot was homogenized at 858 K for 54 ks and 2400 ks, the amount of the β phase decreased, while that of the α′ phase increased. On the other hand, the as-cast 0.5 mass% Fe ingot obtained at the casting cooling rate of 50 K/s had the largest amount of the α phase among the ingots investigated. When this ingot was homogenized at 858 K for 54 ks, a large amount of the α phase remained. However, the homogenization at 858 K for 2400 ks resulted in the transformation of the α phase to the α′ phase. The main phase in the as-cast 0.2 mass% Fe ingot obtained at the casting cooling rate of 5 K/s, close to the industrial cooling rates, was the β phase. The β phase gradually decreased, and the relative amounts of the α and α′ phases increased during homogenization at 858 K for 54 ks. Furthermore, almost all of the Al–Fe–Si intermetallic compounds were transformed into the α′ phase in the ingots homogenized at 858 K for 2400 ks.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...