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  • 1
    ISSN: 1420-908X
    Keywords: Key words: Macrophage metalloelastase — Activation — Cartilage degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: Identify and characterize the matrix metalloproteinase responsible for cartilage proteoglycan degradation mediated by a macrophage cell line in a cell culture model that resembles some aspects of rheumatoid pannus.¶Materials or Subjects: Supernatants from the transformed mouse macrophage cell line J774A.1 were used to purify the proteoglycan degrading activity.¶Methods: J774A.1 macrophage culture supernatants were purified by sequential column chromatography and proteins were identified by zymography, western blotting and amino acid sequence analysis. Cartilage degradation was measured using 35S labeled bovine nasal cartilage.¶Results: The cartilage degrading proteolytic activity in the mouse macrophage supernatants proved to be due to two major proteins with approximate molecular masses of 48 kDa and 22 kDa that were identified as macrophage metalloelastase (MME). Incubation of purified MME at 37°C for up to 16 h resulted in the processing of the 48 kDa protein to several novel bands including a previously undescribed protein of ∼25 kDa without accumulation of fully processed 22 kDa protein. A number of proteinases increased the rate of this processing. J774A.1 macrophage metalloelastase degraded cartilage proteoglycan with an efficiency approximately equal to human macrophage metalloelastase (MMP-12) and matrilysin (MMP-7) and twice that of stromelysin-1 (MMP-3).¶Conclusions: These data identify the cartilage proteoglycan degrading metalloproteinase secreted by J774A.1 macrophages in this cell culture model as MME, and describes mechanisms of activation and processing of this enzyme that may play an important role in cartilage degradation.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 127 (1996), S. 0 
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: In this paper we study, theoretically and numerically, the influence of 2-D and 3-D random isotropic stationary inhomogeneities on the phase velocities of the transmitted compressional wavefield of an initially plane (or spherical) wave. Due to scattering by the inhomogeneities the wavefield becomes distorted as the wave propagates through the medium. The traveltimes fluctuate when considering different wavefield registrations acquired at the points of surfaces that are parallel to the wavefront of the initial wave. It is usually observed that the slowness obtained from the averaged traveltime differs from the averaged slowness of (he medium. In the geophysical lilerature this effect has been termed the ‘velocity shift’.Using the Rytov approximation we establish formulas for the frequency- and travel-distance-dependent phase velocity of the transmitted wavefield in 2-D and 3-D randomly inhomogeneous media. We also compare our analytical results with finite-difference simulations. Good agreement between numerical simulations and theory is observed. The low-frequency limit of our analytical results coincides with the known effective-medium limit of the phase velocity in statistically isotropic inhomogeneous fluids with constant densities. In the high-frequency limit our results coincide with the results previously obtained by the ray-perturbation theory. However, in contrast to the ray theory, our description is not restricted to media with differentiate correlation functions of fluctuations. Moreover, our results quantify the frequency dependence of the velocity shift in the intermediate-frequency range. This frequency dependence is of major importance for estimating this effect in realistic situations.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Surgical endoscopy and other interventional techniques 10 (1996), S. 816-819 
    ISSN: 1432-2218
    Keywords: Key words: Laparoscopy — Laparoscopic training — Inanimate models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: A reliable method supplying graduated experience and practice is needed to develop and refine laparoscopic skills. The laparoscopic surgeon, like the microvascular surgeon, must have ongoing training to refine and maintain his or her skills. Methods: The authors describe a new modular training unit. The unit consists of a box with a built-in television camera, a light source, and a rotating platform. A videotape recorder with a timing device documents the actual ``operating time'' required for the various exercises. The first phase of training consists of a basic skills board. This initial phase enhances the use of dominant and nondominant hand motor activity. Results: The surgeon then progresses to lifelike models (biliary, suturing, hernia, gynecologic) to simulate the human operative setting. Ten surgeons spent 5 h each working with the module. The specific exercises were recorded and timed. Their progress is described. Conclusions: The modular laparoscopic skills center is an integral part of any laparoscopic educational program. It facilitates the acquisition and maintenance of laparoscopic skills.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Surgical endoscopy and other interventional techniques 10 (1996), S. 816-819 
    ISSN: 1432-2218
    Keywords: Laparoscopy ; Laparoscopic training ; Inanimate models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: A reliable method supplying graduated experience and practice is needed to develop and refine laparoscopic skills. The laparoscopic surgeon, like the microvascular surgeon, must have ongoing training to refine and maintain his or her skills. Methods: The authors describe a new modular training unit. The unit consists of a box with a built-in television camera, a light source, and a rotating platform. A videotape recorder with a timing device documents the actual “operating time” required for the various exercises. The first phase of training consists of a basic skills board. This initial phase enhances the use of dominant and nondominant hand motor activity. Results: The surgeon then progresses to lifelike models (biliary, suturing, hernia, gynecologic) to simulate the human operative setting. Ten surgeons spent 5 h each working with the module. The specific exercises were recorded and timed. Their progress is described. Conclusions: The modular laparoscopic skills center is an integral part of any laparoscopic educational program. It facilitates the acquisition and maintenance of laparoscopic skills.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 93 (1997), S. 450-460 
    ISSN: 1432-0533
    Keywords: Key words Hyperbilirubinemia ; Bilirubin ; encephalopathy ; Kernicterus ; Cerebellum ; Purkinje cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The homozygous (jj) Gunn rat provides a model for hyperbilirubinemia which includes prominent cerebellar hypoplasia. Development of the Gunn rat cerebellum was examined with and without the additional effects of elevating brain bilirubin concentration to still higher levels via sulfadimethoxine (sulfa) administration. Homozygous (jj) Gunn rats and heterozygous (Nj) littermate controls (n = 32 each) were given 100 mg/kg sulfa or saline at postnatal days 3, 7, 17, and 30, and most were sacrificed 24 h later (n = 4 for each genotype at each age). Cerebellar volume, total volume and cell number for each deep cerebellar nucleus, densities for Purkinje and granule cells in the cerebellar cortex of lobules II, VI and IX, and the density of vacuolated Purkinje cells were all measured quantitatively. Cytoplasmic vacuolation provided an indication of bilirubin toxicity and was never observed in the Nj control rats. Vacuolated Purkinje cells were first observed in jj-saline rats at 18 days and were found only in the more anterior lobules of the cerebellum (II and VI). By contrast, vacuolated Purkinje cells were observed in jj-sulfa rats at both 4 and 8 days, but only in the most posterior cerebellar lobule (IX). In all older jj rats, the decline in vacuolation was accompanied by significant necrosis and resorption of the Purkinje cells in the anterior lobules. Since the Purkinje cells in the posterior lobules are the first to differentiate in the cerebellum and are resistant to bilirubin toxicity in jj-saline rats, the results support the presence of a critical period when elevated brain bilirubin may be most toxic to neuronal development. The findings suggest that neurons undergoing differentiation at the time of bilirubin exposure are most susceptible to cell death, while cells that are slightly more or slightly less mature may show only transient changes.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of low temperature physics 105 (1996), S. 467-472 
    ISSN: 1573-7357
    Keywords: 75.25.+z ; 75.10.Jm ; 75.40.Gb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Inelastic neutron scattering measurements have been performed on the S=1/2 quasi-one-dimensional system Sr14Cu24O41, which has both simple chains and two-leg ladders of copper ions. We have observed that both the chain and the ladder exhibit a spin gap, which originate from a dimerized state.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1777
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Proteinase 3 (PR3), is a matrix-degrading serine proteinase expressed in different hematopoietic cell lineages. The PR3 protein appears to regulate the myeloid differentiation and was found to be the autoantigen associated with Wegener granulomatosis. We have isolated and characterized the gene for mouse PR3 (mPR3) and determined its chromosomal location. The gene has been localized to Chromosome (Chr) 10. Comparison of mouse PR3 genomic structure with that of its human counterpart indicates that: 1) the mPR3 gene spans 7 kb organized in 5 exons and 4 introns, 2) the codons of His-Asp-Ser of the catalytic site are conserved and spread out over different exons, similar to the human gene, and 3) the gene product encodes a pre-proform of the protein. Knowledge of the structure and chromosomal location of the mPR3 gene may help better the understanding of the temporal and cell-specific expression of mouse PR3.
    Type of Medium: Electronic Resource
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