Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Chemistry  (3)
  • Batrachotoxin  (2)
  • MIP-1α  (2)
  • Batrachotoxin Na+ channel S6 segments Sea anemone toxin Veratridine  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Overproduction of inhibitory hematopoietic cytokines by lipopolysaccharide-activated peripheral blood mononuclear cells in patients with aplastic anemia (1995)
    Springer
    Annals of hematology 71 (1995), S. 281-286 
    Details
    ISSN: 1432-0584
    Keywords: Aplastic anemia ; MIP-1α ; TNF-α ; TGF-β2 ; IFN-γ
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to measure the level of cytokines produced by peripheral blood mononuclear cells (PBMNC) in patients with aplastic anemia (AA) and to determine their effect on the clonal growth of normal bone marrow (BM) cells. Twenty-one patients with AA and 11 normal controls were enrolled in this study. Medium conditioned by PBMNC of AA patients in the presence of lipopolysaccharide (LPS) was found to be suppressive to the colony growth of normal BM cells. Thus, we further determined the presence in the PBMNC-conditioned medium (CM) of both inhibitory cytokines: macrophage inflammatory protein-1α (MIP-1α), tumor necrosis factor-α (TNF-α), transforming growth factor-β2 (TGF-β2), and interferon-γ (IFN-γ), and stimulatory cytokines: interleukin-3 (IL-3) and stem cell factor (SCF). Spontaneous production of MlP-1α was higher in the AA patients than the normal controls (1887±174 pg/ml vs 1643±93 pg/ml), but the difference was not significant. After LPS stimulation, the production of MIP-1α was markedly increased in the AA patients, and its level was significantly higher than that of the normal controls (2360±149 pg/ml vs 1517±92 pg/ml, p=0.0022). The level of TNFα was also higher in the AA patients. However, IFN-γ, TGF-β2, SCF, and IL-3 were not detectable in the PBMNC-CM of either AA patients or normals. The myelopoietic suppressing effect of AA-PBMNC-CM from each AA patient was significantly blocked by pretreatment with anti-TNF-α, resulting in a colony-forming enhancement of 174%±12%. A similar effect was noted in six of 11 AA patients by pretreatment with anti-MIP-1α. We conclude that TNFα and MIP-1α can be overproduced by the PBMNC of some AA patients, which may play a role in the progression of AA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01697980
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Overproduction of inhibitory hematopoietic cytokines by lipopolysaccharide-activated peripheral blood mononuclear cells in patients with aplastic anemia (1995)
    Springer
    Annals of hematology 71 (1995), S. 281-286 
    Details
    ISSN: 1432-0584
    Keywords: Key words Aplastic anemia ; MIP-1α ; TNF-α ; TGF-β 2 ; IFN-γ
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The aim of this study was to measure the level of cytokines produced by peripheral blood mononuclear cells (PBMNC) in patients with aplastic anemia (AA) and to determine their effect on the clonal growth of normal bone marrow (BM) cells. Twenty-one patients with AA and 11 normal controls were enrolled in this study. Medium conditioned by PBMNC of AA patients in the presence of lipopolysaccharide (LPS) was found to be suppressive to the colony growth of normal BM cells. Thus, we further determined the presence in the PBMNC-conditioned medium (CM) of both inhibitory cytokines: macrophage inflammatory protein-1α (MIP-1α), tumor necrosis factor-α (TNF-α), transforming growth factor-β 2 (TGF-β 2), and interferon-γ (IFN-γ), and stimulatory cytokines: interleukin-3 (IL-3) and stem cell factor (SCF). Spontaneous production of MIP-1α was higher in the AA patients than the normal controls (1887±174 pg/ml vs 1643±93 pg/ml), but the difference was not significant. After LPS stimulation, the production of MIP-1α was markedly increased in the AA patients, and its level was significantly higher than that of the normal controls (2360±149 pg/ml vs 1517±92 pg/ml, p=0.0022). The level of TNFα was also higher in the AA patients. However, IFN-γ, TGF-β 2, SCF, and IL-3 were not detectable in the PBMNC-CM of either AA patients or normals. The myelopoietic suppressing effect of AA-PBMNC-CM from each AA patient was significantly blocked by pretreatment with anti-TNF-α, resulting in a colony-forming enhancement of 174%±12%. A similar effect was noted in six of 11 AA patients by pretreatment with anti-MIP-1α. We conclude that TNFα and MIP-1α can be overproduced by the PBMNC of some AA patients, which may play a role in the progression of AA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01697980
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Modification of cloned brain Na+ channels by batrachotoxin (1994)
    Springer
    Pflügers Archiv 427 (1994), S. 309-316 
    Details
    ISSN: 1432-2013
    Keywords: Na+ channel ; Batrachotoxin ; Tetrodotoxin ; Benzocaine ; NaIIA channel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of batrachotoxin (BTX) on cloned α-subunit Na+ channels were examined in CHO-K1 cells (a chinese hamster ovary cell line) transfected with rat brain NaIIA cDNA. Under whole-cell patch clamp conditions, BTX shifted the voltage dependence of the activation process by about 45 mV towards the hyperpolarizing direction and eliminated the inactivating phase of Na+ currents. Repetitive depolarizations greatly facilitated the binding of BTX with NaIIA channels while the membrane was held at −100 mV. In chloramine-T-pretreated cells, the association rate of BTX binding with the NaIIA channel was 6.5-fold faster than that in untreated cells. The estimated association rate constant for BTX binding with the open form of NaIIA channel was 1.11×106 mol−1·s−1 at room temperature. BTX-modified NaIIA channels were blocked by tetrodotoxin (TTX) in a complicated manner. First, the TTX binding to the closed state of BTX-modified NaIIA channels was not voltage dependent. The K D value of TTX was measured at 8.9 nM, which was similar to that of unmodified channels (K D=14.2 nM). Second, the block of the open state of BTX-modified NaIIA channels by TTX was voltage dependent; depolarization reduced the potency of TTX block between −20 mV to +50 mV. Below −30 mV, the TTX affinity began to level off, probably because of the increased presence of the closed state. Unexpectedly, steady-state inactivation of BTX-modified NaIIA channels was minimal as measured by the two-pulse protocol, a phenomenon distinctly different from that found in GH3 cells. Neutral local anesthetic benzocaine, however, drastically enhanced the steady-state inactivation of BTX-modified NaIIA channels, with its maximal effect around −60 mV. We conclude that BTX can bind and modify the NaIIA α-subunit. However, a specific subtype of α-subunits and/or an unidentified modulating process may be required for the optimal steady-state inactivation of BTX-modified Na+ channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374539
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Modification of wild-type and batrachotoxin-resistant muscle µ1 Na+ channels by veratridine (2000)
    Springer
    Pflügers Archiv 439 (2000), S. 705-713 
    Details
    ISSN: 1432-2013
    Keywords: Batrachotoxin Na+ channel S6 segments Sea anemone toxin Veratridine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Biochemical evidence indicates that veratridine (VTD) and batrachotoxin (BTX) share a common binding site in Na+ channels. Under whole-cell voltage-clamp conditions, we examined this single receptor hypothesis by studying the VTD phenotype in BTX-resistant muscle Na+ channels, µ1-I433K, N434K, L437K, F1579K, and N1584K. Derived from point mutations at segments D1–S6 and D4–S6, these mutant Na+ channels are resistant to 5 µM BTX when expressed in human embryonic kidney cells. In contrast to the wild-type phenotype, VTD at 200 µM elicits little or no maintained current during a test pulse at +50 mV, and little or no "tail" current after the test pulse in all BTX-resistant mutant channels. Paradoxically, VTD retains its ability to inhibit the peak Na+ current in BTX-resistant mutant Na+ channels. To explain these mutant phenotypes, we propose a two-step binding reaction scheme. An initial VTD-binding interaction with the Na+ channel results in the inhibition of peak current amplitude, and a second binding reaction results in the trapping of VTD within the D1–S6 and D4–S6 domain interface. The failure of BTX-resistant mutant Na+ channels to trap VTD suggests that segments of D1–S6 and D4–S6 form a common receptor for VTD and BTX.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004249900229
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Slow inactivation of muscle μ1 Na+ channels in permanently transfected mammalian cells (1996)
    Springer
    Pflügers Archiv 432 (1996), S. 692-699 
    Details
    ISSN: 1432-2013
    Keywords: Key words Na+ channel ; Slow inactivation ; μ1 channel ; Chloramine-T ; Batrachotoxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The slow inactivation of cloned muscle α-subunit Na+ channels was investigated using a Chinese hamster ovary cell line permanently transfected with rat muscle μ1 cDNA. Expression of μ1 Na+ channels was found in cells maintained for more than 6 months after transfection; 〉 70% of cells expressed ≥ 3 nA of Na+ current at +30 mV under whole-cell patch-clamp conditions. As expected, Na+ currents in these cells were blocked by tetrodotoxin as well as by μ-conotoxin. After prolonged depolarization (10 s at +30 mV) to inactivate voltage-gated Na+ channels, Na+ currents slowly reappeared over a time course of several minutes, during which time the cell was repolarized to the holding potential of −100 mV. This recovery from slow inactivation was best fitted by a double exponential function with τ1 = 2.5 s (amplitude = 53%) and τ2 = 83.4 s (amplitude = 38%). In contrast, the development of slow inactivation at +30 mV was best fitted by a single exponential function, with τ = 3.0 s. Steady-state slow inactivation (s ∞) had a midpoint potential (s 0.5) of −52 mV and a slope factor (k) of 7.8 mV. Elimination of fast inactivation by treatment with chloramine-T accelerated the development of slow inactivation significantly (by ≈four fold) but had little effect on recovery or on steady-state slow inactivation. Finally, as in cloned brain NaIIA Na+ channels, batrachotoxin abolished both fast and slow inactivation of μ1 Na+ channels. These results together suggest that slow inactivation takes place in the α-subunit of μ1 muscle Na+ channels and is governed by a μl protein region different from that governing fast inactivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050187
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Reconstruction of oil saturation distribution histories during immiscible liquid-liquid displacement by computer-assisted tomography (1984)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 30 (1984), S. 642-646 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690300418
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Raman study of temperature-induced phase transitions in lead hafnate (PbHfO3) (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 25 (1994), S. 331-334 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Results of a high-temperature Raman spectroscopic investigation up to 522 K carried out at ambient pressure on an antiferroelectric PbHfO3 multi-domain single crystal are reported. The changes in the Raman spectral features show that temperature-induced phase transitions occur at 435 ± 1 and at 484 ± 1 K. The first transition is possibly to a tetragonal structure and the second is to the cubic perovskite phase. The behavior is consistent with the earlier x-ray study of PbHfO3. No soft mode behavior associated with the transitions was detected in the Raman spectra of PbHfO3. The changes observed in the high-temperature Raman spectra of PbHfO3 are similar to those found in the spectra of isostructural PbZrO3.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250250508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    High-pressure Raman study of SrMoO4 up to 37 GPa and pressure-induced phase transitions (1995)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 26 (1995), S. 451-455 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Pressure-induced phase changes in SrMoO4 were investigated by high-pressure Raman spectroscopy in a diamond anvil cell. The scheelite-type SrMoO4 transforms in to a monoclinic lattice near 13 GPa and retains this structure up to 37 GPa, the limit of pressure tested. There is no pressure-induced amorphization in this simple molybdate up to this pressure, as in the case of structurally complex molybdate systems. The optical absorption characteristics of SrMoO4 change considerably with pressure, the sample turning progressively deep orange-brown with increase in pressure. This change is connected with the lowering of the d-state of molybdenum in the MoO4 ion with increase in pressure.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250260609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...