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  • 1
    Electronic Resource
    Electronic Resource
    On the Alkali Metal Salts Derived from the Diammoniate of Diborane1 (1956)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 78 (1956), S. 725-728 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01585a010
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  • 2
    Electronic Resource
    Electronic Resource
    Molecular dynamics of water in oriented DPPC multilayers studied by quasielastic neutron scattering and deuterium-nuclear magnetic resonance relaxation (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 100 (1994), S. 3307-3316 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The dynamics of water between highly oriented multilayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) has been studied in two time domains at different hydration levels. Incoherent quasielastic neutron scattering (QENS) and deuterium-nuclear magnetic resonance (NMR) longitudinal (T1) relaxation were employed to investigate both the high-frequency motions of water (10−9–10−11 s time scale) and their anisotropy, while 2H-NMR transverse (T2) relaxation was used for obtaining information on low frequency dynamical processes (microsecond time scale). Our results show that high frequency dynamics (picosecond-time scale) at low hydration (three to four water molecules per lipid) can be understood solely as a uniaxial rotation of the water molecules tightly bound to DPPC head groups with a correlation time τrot≈62 ps at 55 °C and a rotational radius of 1±0.1 A(ring), but with no detectable translational degrees of freedom. The 2H-NMR T1 data (nanosecond-time scale) can be explained satisfactorily on the basis of fast rotations with the correlation time above and a slower reorientation of the rotational axis (correlation time τ1≈6 ns).Both QENS and 2H-NMR T1 measurements provide an apparent activation energy of Ea=32±1.0 kJ/mol for this process. Increasing the hydration level of the multilayers leaves the rotational motion essentially unchanged, but enables additional translational motion which can be considered as a jump diffusion process (diffusion coefficient D=16±1×10−10 m2/s at 44 °C and a mean residence time of τ0=2.0±0.5 ps) of nonbound water. It is interesting to note that this diffusion is completely isotropic on the characteristic length scale of this QENS experiment (≤10 A(ring)). Temperature variation shows that the phase state of the lipids has no significant effect on the high frequency dynamics of the water molecules. Measurements of the 2H-NMR quadrupolar splitting of water (D2O) at temperatures around the phase transition temperature Tm of the oriented DPPC multilayers clearly show a coexistence of the crystalline Lβ' phase and of the fluid Lα phase over a range of up to 4 °C at both sides of Tm. The intermediate Pβ' ("ripple'') phase is suppressed as we worked at hydration levels below saturation. In the coexistence range, exchange of water takes place between crystalline and fluid lipid domains due to water diffusion. This exchange causes a pronounced minimum of the 2H-NMR transverse relaxation time T2 at Tm since this low frequency process satisfies approximately a critical damping condition for a two-site chemical exchange process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.466422
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  • 3
    Electronic Resource
    Electronic Resource
    Processing of POMC peptides by dermal microvascular endo-thelial cells: implication for EC biologic functions and skin inflammation (2004)
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc.
    Experimental dermatology 13 (2004), S. 0 
    Details
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Dermal microvascular endothelial cells (ECs) are both source and target of the pro-opiomelanocortin (POMC) peptides ACTH and α-melanocyte-stimulating hormone (α-MSH). The availability of neuropeptides as important modulators of innate and adaptive immune responses is controlled by neuropeptide-specific peptidases such as neutral endopeptidase (NEP) or angiotensin-converting enzyme (ACE). In this study, we have tested the possibility that NEP or ACE expressed by ECs may influence the local bioavailability of POMC peptides. Incubation of ACTH1−39 with cell membranes prepared from the high NEP-/low ACE-expressing microvascular EC line 1 (HMEC-1) or from low NEP-/high ACE-expressing primary human dermal ECs (HDMECs) for 30–480 min resulted in a decrease in ACTH immunoreactivity (IR) over time in membrane supernatants that could be partially blocked with NEP inhibitors as detected by radioimmunoassay. In parallel, α-MSH IR increased peaking after 60 min. Fragments generated by incubation of HMEC-1 or HDMEC membranes with ACTH1−39, ACHT1−24 or α-MSH for 1–120 min were further analysed by mass spectroscopy. HMEC-1 membranes generated peptide products which could be altered by inhibition of NEP, but not ACE. Likewise, HDMEC membranes fragmented ACTH similar to HMEC-1 membranes in the presence of NEP inhibitors. Some of the proteins can be assigned to regular proteolytic cleavage, while others seem to be modified. Importantly, HMEC-1 and HDMEC membranes also slowly degraded α-MSH, suggesting that EC proteolytic peptidases locally control ACTH/α-MSH bioavailability, which may be important in controlling cutaneous inflammation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.0906-6705.2004.0212cc.x
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  • 4
    Electronic Resource
    Electronic Resource
    Molecular analysis of different phases in human wound healing (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Experimental dermatology 6 (1997), S. 0 
    Details
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract Cultured granulation fibroblasts grown from punch biopsies of the same lower arm area, obtained 3, 6, 9 and 14 days after wounding, were used as a human wound healing model in comparison to quiescent fibroblasts. We investigated the expression of key extracellular matrix components at the protein level by flow cytometry and mRNA steady state levels by Northern blotting of the different fibroblasts and compared these data to the ability to migrate towards a chemotactic signal. Procollagen α1 (I), fibronectin and matrix metalloprotease-1 synthesis was strongly upregulated at the mRNA steady state level on days 3 and 14. Tissue inhibitor of metalloprotease-1 mRNA is only 20% down-regulated between day 3 and 14. Chemotaxis towards conditioned medium reflects a net effect of several factors and is distinctly different from chemotaxis towards platelet-derived growth factor, which peaks at day 3. Compared to the protein level, the enhanced expression of the corresponding PDGF receptor β chain mRNA is delayed by 3 to 6 days. PDGF receptor α shows no regulatory changes during the observation period. This data further supports the idea that functionally divergent subpopulations of fibroblasts exist during wound healing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0625.1997.tb00160.x
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  • 5
    Electronic Resource
    Electronic Resource
    Production and processing of POMC peptides by dermal microvascular endothelial cells (EC): modulation of EC biologic functions and implication for skin inflammation. (2005)
    Oxford, UK; Malden, USA : Munksgaard International Publishers
    Experimental dermatology 14 (2005), S. 0 
    Details
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The availability of neuropeptides or neuroendocrine hormones as important modulators of innate and adaptive immune responses is effectively controlled by neuropeptide-specific peptidases. In previous studies, drug inhibition or genomic deletion of neutral endopeptidase (NEP, CD10) or of angiotensin-converting enzyme (ACE, CD143) resulted in a profound augmentation of murine allergic contact dermatitis responses. Likewise, we have identified dermal microvascular endothelial cells (EC) as both source and target of the proopiomelanocortin (POMC) peptides ACTH and α-melanocyte-stimulating hormone (α-MSH), in particular. EC express melanocortin receptor (MC-) 1 and α-MSH is capable of profoundly downregulating LPS- or cytokine-induced expression of adhesion molecules in vitro and of endotoxin-induced cutaneous vasculitis in vivo. In this study, we have tested the hypothesis that NEP or ACE expressed by EC may influence the local bioavailability of POMC peptides. Cell membranes prepared from the high NEP/low ACE expressing human microvascular endothelial cell line 1 (HMEC-1) or from low NEP/high ACE expressing primary human dermal EC (HDMEC) were incubated for 30–480 min with ACTH1–39 in the presence or absence of NEP or ACE inhibitors, respectively. Analysis of membrane supernatants for ACTH and α-MSH by radioimmunoassay revealed a decrease in ACTH immunoreactivity (IR) over time that could be partially blocked with NEP inhibitors. In parallel, α-MSH IR increased peaking after 60 min. Fragments generated by incubation of HMEC-1 or HDMEC membranes with ACTH1–39, ACHT1–24 or α-MSH for 1–120 min were further analyzed by Matrix-assisted-LASER desorption time-of-flight (MALDI-TOF) spectroscopy. HMEC-1 membranes generated main peptide products with molecular masses of 2007, 1057 and 945, respectively, from ACTH1–39, and 1057 from ACTH1–24. Inhibition with NEP, but not ACE inhibitors altered the fragmentation profile indicating that NEP is involved in degradation of both ACTH1–39 and ACTH1–24. Likewise, HDMEC membranes fragmented ACTH similar to HMEC-1 membranes in the presence of NEP inhibitors. Both HMEC-1 and HDMEC membranes were also capable of slowly degrading α-MSH suggesting that EC proteolytic peptidases are important for the local control of ACTH/α-MSH bioavailability, which may play a significant role in controlling local cutaneous inflammatory responses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.0906-6705.2005.0266r.x
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  • 6
    Electronic Resource
    Electronic Resource
    GM-2 gangliosidosis (Sandhoff's disease): two year follow-up by MRI (1994)
    Springer
    Neuroradiology 36 (1994), S. 152-154 
    Details
    ISSN: 1432-1920
    Keywords: GM-2 gangliodoses-Sandhoff's disease ; MRI
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two children with GM-2 gangliosidosis type 0 (Sandhoff's disease) followed up by MRI at 1.5 Tesla for 1.8 years are reported. One was presymptomatic at the first MRI examination. As her neurological status deteriorated, MRI showed low signal in bilaterally, on T2-weighted images the white matter with involvement of the optic radiations. In the second, MRI correlated well with the clinical progression of the disease, showing in the different stages involvement of thalamus and basal ganglia. There was no contrast enhancement and the grey matter remained normal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00588086
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  • 7
    Electronic Resource
    Electronic Resource
    Die Erythrocytenaggregation bei Menschen mit Risikofaktoren eines Herzinfarkts (1975)
    Springer
    Journal of molecular medicine 53 (1975), S. 385-389 
    Details
    ISSN: 1432-1440
    Keywords: Coronary heart disease ; myocardial infarction ; risk factors ; erythrocyte aggregation ; cell volume distribution ; Koronare Herzkrankheit ; Herzinfarkt ; Risikofaktoren ; Erythrocytenaggregation ; Erythrocytenvolumenverteilung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die in-vitro-Messung der Erythrocytenaggregation wurde so verbessert, daß der Variationskoeffizient auf ±14,2% herabgedrückt wurde. 2. Mit der verbesserten Methode konnten die früheren Befunde statistisch hochsignifikant gesichert werden, daß sonst gesunde starke Raucher einen wesentlichen höheren Erythrocytenaggregationswert aufweisen als Nichtraucher. 3. Es wurde auch bei anderen Risikofaktoren koronarer Herzerkrankungen nachgewiesen, daß sie zu einer Erhöhung des Aggregationswerts der Erythrocyten führen. Insbesondere konnte dies bei Hypercholesterinämie nachgewiesen werden. 4. Mehrere Risikofaktoren beim gleichen Patienten bewirken einen überadditiv hohen Aggregationswert der Erythrocyten.
    Notes: Summary 1. The vitro test for red blood cell aggregation has been improved, the coefficient of variation was decreased to 14.2. 2. By the improved method the earlier findings were confirmed with high statistical significance that heavy smokers have a significantly higher red blood cell aggregation value in comparison with nonsmokers. 3. It could be shown that other coronary risk factors, especially hypercholesterolaemia, increase the aggregation value too. 4. The aggregation of red blood cells increases in the presence of several coronary risk factors in the same patient to higher values than expected from the addition of the aggregations caused by single risk factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01468677
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  • 8
    Electronic Resource
    Electronic Resource
    Endogenous gonadal, LH and molt rhythms in tropical stonechats: effect of pair bond on period, amplitude, and pattern of circannual cycles (1995)
    Springer
    Journal of comparative physiology 177 (1995), S. 73-79 
    Details
    ISSN: 1432-1351
    Keywords: Circannual rhythms ; Saxicola torquata ; Tropical birds ; Reproductive cycles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To investigate the effects of reproduction and associated stimuli on the circannual cycles of African stonechats Saxicola torquata axillaris birds were held for 29 months in aviaries under a constant equatorial (12.25 h) photoperiod, either singly (10 females and 10 males) or in 10 male/female pairs. The birds of all 3 groups went through circannual cycles in gonadal size, plasma LH and molt, but groups differed with regard to actual reproductive performance. During the second cycle, only one of the singly-held females laid eggs and incubated. In constrast, in the paired females egg-laying and incubation occurred in all but one bird. About 50% of the clutches from paired females contained fertilized eggs confirming the expectation of behavioral differences between the paired and unpaired birds. However, despite differences in reproductive performance there were no differences in either circannual period or duration of reproductive phases. Moreover, there was no correlation between number of broods produced per season and circannual parameters of the paired females. Therefore, the temporal course and, particularly, the period during which reproduction is possible is rigidly determined by an endogenous program that is not influenced by reproductive performance. A rigid program of this kind may be advantageous in the tropics because it prevents prolongation of the breeding season in years with favourable conditions which in turn could jeopardize optimal timing of breeding in the following year and thus reduce lifetime reproductive success.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00243399
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  • 9
    Electronic Resource
    Electronic Resource
    Allgemeines (1979)
    Springer
    Archives of gynecology and obstetrics 228 (1979), S. 42-48 
    Details
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02427486
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  • 10
    Electronic Resource
    Electronic Resource
    A comparison of DMPC membranes mixed with melittin or C12E5 (1994)
    Springer
    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1585-1594 
    Details
    ISSN: 0392-6737
    Keywords: Molecular biophysics ; Defects in liquid crystals ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The effect of adding the defect-forming molecules melittin and C12E5 to DMPC membranes has been studied and the corresponding phase diagrams established. Light, X-ray and neutron small-angle scattering have been used to characterize the mixed membranes. Both systems show a melting of the lamellar Lα into an isotropic phase upon addition of the second membrane constituent. The molar ratio, where the melting occurs is the same in concentrated and dilute samples. For the DMPC/C12E5 system not only membrane composition, but also temperature can be used to induce a transition from an isotropic to a lamellar phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02462046
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