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 Betacellulin ; epidermal growth factor ; epidermal growth factor receptor ; differentiation ; ErbB [Diabetologia (1998) 41: 623 ; 628]
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Betacellulin is a member of the epidermal growth factor family and converts pancreatic AR42J cells into insulin-producing cells. This study was conducted to characterise the receptor for betacellulin in AR42J cells. AR42J cells expressed two classes of binding sites for radioactive iodine labelled betacellulin, with Kd values of 4.6 × 10− 11 mol/l and 3.0 × 10− 10 mol/l. The binding of [125I]betacellulin was inhibited by unlabelled betacellulin in a dose-dependent manner, but epidermal growth factor was 50 fold less effective than betacellulin. Affinity cross-linking showed a [125I]betacellulin-binding protein with a molecular weight of approximately 180 KDa. When this protein was immunoprecipitated with antibody against epidermal growth factor receptors ErbB-1, ErbB-2, ErbB-3 or ErbB-4, it was immunoprecipitated only by the anti-ErbB-1 antibody. When the [125I]betacellulin-labelled proteins were immunoprecipitated with a combination of the four ErbB antibodies, and the unprecipitated proteins were then immunoprecipitated with anti-phosphotyrosine antibody, a 190 KDa protein was observed. Betacellulin induced the tyrosine phosphorylation of ErbB-1, ErbB-2 and ErbB-4. Finally, while 100 pmol/l betacellulin converted all of the AR42J into insulin-producing cells in the presence of activin A, 10 nmol/l epidermal growth factor induced differentiation in only about 30 % of the cells. Higher concentrations of epidermal growth factor were less effective. Neu differentiation factor in the presence or absence of epidermal growth factor was ineffective. These results indicate that betacellulin binds to ErbB-1 and possibly another protein with a molecular weight of 190 KDa. The latter betacellulin-binding protein may be involved in the differentiation-inducing activity of betacellulin.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0630
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-1106
    Keywords: Optical response ; Neostriatal slice ; GABA ; Glutamate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of GABA and glutamate antagonists as well as dopamine agonists and antagonists on the optical responses of neostriatal (Str) slices to local electrical stimulation were examined using a voltage-sensitive dye and a high-speed image sensor. A single local stimulation applied to the Str slices evoked optical responses lasting for 40–80 ms and propagating in every direction up to about 1.5 mm. Bath application of bicuculline methiodide increased the intensity and duration of optical responses, while their spatial response patterns were unchanged. Bath application of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) greatly reduced the late part of responses occurring about 4 ms after stimulation, but the early part of responses was unaffected by CNQX. The early part of the response was eliminated by application of tetrodotoxin. Bath application of N-methyl-D-aspartate antagonists, 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid and 2-amino-5-phosphonovaleric acid resulted in only small changes in the optical responses. Bath application of D1 agonist 6-chloro-7,8-dihydroxy-3-allyl-1-phenyl-2,3,4,5,-tetrahydro-1H-3-benzazepine hydrobromide consistently increased the intensity but decreased the speed of propagation and duration of the optical reponse. Bath application of D2 agonist quinpirole had no effect on the optical response. D1 antagonist SCH 23390 and D2antagonist sulpiride also failed to change optical responses. These results indicate that the early part of the reponse is due to direct activation of the neuronal elements by electrical stimulation, while the late part of the response is due mainly to glutamatergic ex-citatory postsynaptic potentials (EPSPs) mediated by α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptors. This study also suggests that dopamine may modulate AMPA/kainate responses through D1 receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 54 (1998), S. 479-481 
    ISSN: 1432-1041
    Keywords: Key words CYP2D6 ; CYP2C19 ; Elderly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Eighty-three healthy elderly Swedish subjects (age 87 ± 4 years, mean ± SD, range 80–98 years) were genotyped with respect to the two genetic polymorphisms of oxidative drug metabolism, CYP2D6 and CYP2C19, using allele-specific polymerase chain reaction (PCR). A control population consisted of 248 younger unrelated healthy volunteers (age 31 ± 9 years, range 19–63 years) for CYP2D6, and 162 (age 30 ± 8 years, range 19–55 years) for CYP2C19. Results: No significant differences were found between the control groups and the elderly subjects with respect to the frequencies of the defect alleles CYP2D6*3, CYP2D6*4, CYP2C19*2 and CYP2C19*3. Neither were there any differences in the genotype frequencies, or the predicted phenotype frequencies. The study indicates that the CYP2D6 and CYP2C19 genotypes play no major role in the probability of reaching high age. Conclusion: No genetically determined differences in the pharmacokinetics of drugs metabolized by these two polymorphic enzymes are to be expected in the oldest age groups compared with younger adults.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1076
    Keywords: EEG ; Evoked potentials ; Newborn ; Intracranial hemorrhage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The EEG, visual and auditory evoked potentials (VEP, AEP) were evaluated in 16 full-term newborn infants who had intracranial hemorrhage documented by computerized tomography (CT). Three of them had supratentorial, three, supra- and infratentorial hemorrhage, while the other ten had infra- or peri-tentorial bleeding. Three died during the neonatal period. Eight of the 13 surviving infants were neurologically normal and five were abnormal at the time of the follow-up. Those who had normal or mildly abnormal background EEGs all developed normally, while those whose neonatal EEG was severely abnormal subsequently developed neurological sequelae irrespective of the extent of intracranial hemorrhage. The EEG, VEP or AEP is of little value in the diagnosis of intracranial bleeding but the EEG is valuable in assessing the degree of associated parenchymatous damage and is of great prognostic significance.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1041
    Keywords: Phenytoin ; Gingival hyperplasia ; p-HPPH enantiomers ; CYP2C ; fibroblast culture ; adverse effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The purpose of this study was to assess the possible role of the (R)- and (S)- enantiomers of the phenytoin metabolite p-HPPH in the pathogenesis of gingival hyperplasia (GH). About 98% of circulating p-HPPH is in the (S)-form. There were significant differences between patients with and without GH in (R)-p-HPPH level (0.055 vs 0.042 μg·ml−1), both enantiomer/racemate level ratios, and R/S enantiomeric ratio (0.0313 vs 0.0232); an increase in serum (R)-p-HPPH level was observed in patients with GH. In separate experiments, the effect of p-HPPH enantiomers on the proliferation of the normal human dermal fibroblast was studied. The in vitro study showed that (R)-p-HPPH selectively stimulated fibroblast growth. The results suggest that the least abundant metabolite, (R)-p-HPPH, is the most toxic with respect to gingival hyperplasia.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 52 (1980), S. 273-280 
    ISSN: 0942-0940
    Keywords: Cranioplasty ; acrylic resin ; coating method ; skull bone defect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cranioplasty utilizing a resin-coated preserved autogenous skull flap was devised and used in 36 cases, 14 of them being followed up radiologically. It has been confirmed that this method is advantageous in that it repairs the skull defect satisfactorily both from surgical and cosmetic points of view. Furthermore this method causes no anxiety to the patient because of the autogenous origin of the bone flap. We recommend this method for cranioplasty when an autogenous bone flap is preserved.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0942-0940
    Keywords: Brain tumours ; LDH isoenzyme ; cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lactate dehydrogenase (LDH) isoenzyme patterns in benign and malignant brain tumours were determined by means of electrophoresis of the cell extracts and selective cytochemical stain of the smears. The LDH isoenzyme distribution of the cell extracts showed a pronounced cathodal shift in the malignant gliomas and metastatic carcinomas. Normal brain tissues and histologically benign gliomas, however, showed an anodal pattern with a dominance of the H-type LDH. Schwannomas and meningiomas had a midzone isoenzyme pattern with a dominant LDH3 fraction. Pituitary adenomas usually showed the LDH pattern similar to that of the normal cerebrum. The LDH M fraction could be cytochemically verified using an inhibitory effect by 2.6 M urea in staining. Astrocytomas grades 3–4 and metastatic carcinomas were characterized by loss or marked reduction of stainability by urea treatment, while astrocytomas grades 1–2 and oligodendrogliomas were resistant to urea inhibition.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The Advanced Toroidal Facility (ATF) [Fusion Technol. 10, 179 (1986)] is the world's largest stellarator. It was designed and built to demonstrate high beta, steady-state operation in a toroidal confinement system. During its final operating period ATF achieved pulse lengths of over one hour (4667 s). The objectives of these experiments were (1) investigation of plasma performance at times that are long compared to the plasma/wall equilibrium time; (2) determination of plasma control and wall conditioning techniques; and (3) adaptation of plasma diagnostic and data acquisition systems to long-pulse operation. Other experiments have also extended earlier studies of dimensionless-parameter plasma confinement scaling. By employing two discrete electron cyclotron heating (ECH) frequencies (28 and 35 GHz), and by simultaneously modulating the ECH power, magnetic field, and plasma density, it has been possible to maintain fixed plasma beta and collisionality while modulating the normalized gyroradius. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The Large Helical Device (LHD) experiments [O. Motojima, et al., Proceedings, 16th Conference on Fusion Energy, Montreal, 1996 (International Atomic Energy Agency, Vienna, 1997), Vol. 3, p. 437] have started this year after a successful eight-year construction and test period of the fully superconducting facility. LHD investigates a variety of physics issues on large scale heliotron plasmas (R=3.9 m, a=0.6 m), which stimulates efforts to explore currentless and disruption-free steady plasmas under an optimized configuration. A magnetic field mapping has demonstrated the nested and healthy structure of magnetic surfaces, which indicates the successful completion of the physical design and the effectiveness of engineering quality control during the fabrication. Heating by 3 MW of neutral beam injection (NBI) has produced plasmas with a fusion triple product of 8×1018 keV m−3 s at a magnetic field of 1.5 T. An electron temperature of 1.5 keV and an ion temperature of 1.4 keV have been achieved. The maximum stored energy has reached 0.22 MJ, which corresponds to 〈β〉=0.7%, with neither unexpected confinement deterioration nor visible magnetohydrodynamics (MHD) instabilities. Energy confinement times, reaching 0.17 s at the maximum, have shown a trend similar to the present scaling law derived from the existing medium sized helical devices, but enhanced by 50%. The knowledge on transport, MHD, divertor, and long pulse operation, etc., are now rapidly increasing, which implies the successful progress of physics experiments on helical currentless-toroidal plasmas. © 1999 American Institute of Physics.
    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...