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  • Cell & Developmental Biology  (5)
  • crystal structure  (5)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 447-461 
    ISSN: 0886-1544
    Keywords: chemokinesis ; orthokinesis ; klinokinesis ; polymorphonuclear leucocytes ; locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Evidence is presented to show that klinokinesis, which was previously demonstrated in bacteria and amoeba only, may also occur in metazoan cells. The chemotactic peptide formyl-Met-Leu-Phe (fMLP) elicited orthokinetic and klinokinetic responses of human blood-borne polymorphonuclear leucocytes (PMNs) under the test conditions used. Increased speed (orthokinesis) was due to an increase in the proportion of migrating cells as well as in the speed of the locomoting subset. The klinokinetic effect was manifested by a decrease in the klinolocomotion index, the mean angle of changes in direction ≥ 90°, and the frequency of turns ≥ 90°. The klinolocomotion index was inversely related to speed. This explains the synergistic effect of klinokinesis and orthokinesis in this system. Colchicine alone had and orthokinetic effect which was exclusively due to alterations in the proportion of migrating cells and it altered the turning behaviour without exerting a klinokinetic effect. However, colchicine had marginal orthokinetic and klinokinetic effects on fMLP-stimulated cells resulting in reduced translocation. The relationship between klinokinesis and mean angle or frequency of turns has been analysed. Klinokinesis was a substantial though not the major element of the chemokinetic response to fMLP under the conditions used. No other metazoan cells have been shown to possess such a complete pattern of responses, including orthokinesis, klinokinesis, and chemotaxis, which regulate locomotion.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 25 (1993), S. 10-18 
    ISSN: 0886-1544
    Keywords: microtubules ; blebs ; locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Colchicine-induced stimulation of polymorphonuclear leukocyte (PMN) locomotion is an interesting model because extension of blebs at the front occurs at a rate (about 2.4 μm/s) which is far above that reported for growth of actin filaments. The following cytoskeletal changes were observed in colchicine-treated PMNs: (1)a small increase in cytoskeleton-associated actin was noted, as well as a somewhate more pronounced increase in cytoskeleton-associated α-actinin, as compared with untreated or DMSO-treated controls. There was, however, no measurable increase in F-actin as determined by NBD-phallacidin blinding; (2)the values for the ratio (α-actinin/actin) are lower in PMNs treated with colchicine for 30 min, as compared with PMNs stimulated with fNLPNTL for 1 minute (non-polar ruffling cells) or 30 min (polarized locomoting cells); thus, this ratio may depend on the type of PMN motility; (3) in polarized PMNs F-actin was mainly located linearly all along the cell membrane; there was more intense staining at the front of the cells; (4) α-actining appeared to colocalize with F-actin at the leading front, but not with F-actin at the tail of polarized cells; (5) myosin was preferentially found at the rear part of polarized cells but not or only to a small extent at the front. Our data indicate a close functional correlation between microtubules and microfilaments. We speculate that F-actin in combination with α-actinin promotes expansion of pseudopods, whereas myosin combined with F-actin promotes contraction. In more general terms we suggest that different forms of PMN motility are generated by differential selective interaction of cytoskeletal compnents and variations in the composition of the cytoskeleton in different sites of the same cells. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 3 (1983), S. 47-60 
    ISSN: 0886-1544
    Keywords: neutrophil granulocytes ; motility ; locomotion ; cell-shape ; cell-substratum adhesion ; f-Met-Leu-Phe ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Activation of the motile apparatus by chemokinetic factors cannot be reliably assessed in cells that are attached to a solid substratum because motility can be totally abolished by excessive adhesion. It is however, necesary to quantify the activation of the motile apparatus in order to analyze and understand chemokinetic responses.It was the purpose of the present work to establish morphological criteria that can be used to quantify motility in nonadherent (floating) neutrophils and to predict the locomotor response under conditions of limited adhesion. The proportion of neutrophils performing crawling-like movements (polarized cells) in suspension correlates very closely with stimulated locomotion at low to optimal concentration of f-Met-Leu-Phe, ie, under conditions of limited adhesion. Reduced locomotion at supraoptimal concentrations of f-Met-Leu-Phe has also morphological correlates. The major feature is the decrease in the proportion of neutrophils performing crawling-like movements and the corresponding appearance of cells that are motile but not polarized in suspension and that do not locomote on the substratum. Concentration-dependent changes in neutrophil length and in the proportion of polarized neutrophils with and without tail were also observed. The locomotor potential of neutrophils under conditions of limited contact with the substratum can be predicted on the basis of their motile behavior, in particular the proportion of cells showing crawling-like movements, in suspension. In combination with measurements of adhesion the procedure should permit a more complete analysis of the regulation of chemokinetic responses.
    Additional Material: 8 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 161 (1994), S. 526-536 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using two newly synthesized inhibitors, Ro 31-8220 and CGP 41 251, of protein kinase C (PKC), we analyzed: (1) how distinct PMN functions (shape changes, locomotion, pinocytosis) are regulated, and (2) the role of protein phosphorylation and PKC in this process. We were able to transform: (1) resting PMNs into locomoting cells using fNLPNTL, (2) locomoting cells into non-locomoting highly pinocytic cells using PMA, and (3) PMA-stimulated cells showing marked pinocytosis into locomoting or into resting cells using Ro 31-8220. It is thus possible to selectively manipulate PMN function (resting state, locomotion, marked pinocytosis), indicating that there are different regulatory pathways. It was not possible to induce locomotion and marked pinocytosis simultaneously, indicating crosstalk between pathways. Ro 31-8220 inhibited PMA-induced shape changes (nonpolar cells) and pinocytosis, but not fNLPNTL-induced shape changes (polarity) and pinocytosis. At higher concentrations, Ro 31-8220 alone elicited cell polarity and chemokinesis, indicating that a constitutively active protein kinase is involved in maintaining the spherical shape of resting PMNs. Functional effects of another PKC inhibitor, CGP 41 251, on neutrophil function were strikingly different. CGP 41 251 selectively inhibited fNLPNTL-induced polarity and locomotion (but not colchicine or Ro 31-8220-induced polarity), and it failed to inhibit PMA-induced, stimulated pinocytosis and shape changes. Although the effects of Ro 31-8220 vs. CGP 41 251 on PMN function were strikingly different, the inhibition of profiles for constitutive and for fNLPNTL- or PMA-induced protein phosphorylation in intact PMNs showed only small differences, which could not yet be conclusively related to cell function. © 1994 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 663-669 
    ISSN: 0044-2313
    Keywords: Dicopper(I)-octa-μ3-halogeno-hexahalogeno-octahedro-hexamolybdate(II) ; crystal structure ; Mo6X14-group ; trigonal planar CuX3-group ; ionic conduction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trigonal Planar CuX3-Groups in Cu2Mo6X14, X = Cl, Br, ICu2Mo6Cl14 (I), Cu2Mo6Br14 (II) and Cu2Mo6I14 (III) were synthesized by thermal treatment of corresponding mixtures of copper(I) and molybdenum(II) halides. The crystal structures were determined by single crystal X-ray analyses. I and II show isotypism, cubic, Pn3 (no. 201, sec. setting), Z = 4, I: a = 12.772(3) Å, II: a = 13.350(2) Å. III shows a new structural type, orthorhombic, Pbca (No. 61), Z = 4, a = 16.058(3) Å, b = 10.643(2) Å, c = 16.963(3) Å. Trigonal planar CuX3 units were found in I—III. Structural behaviour relations are discussed, especially with regard to ionic conductivity.
    Notes: Cu2Mo6Cl14 (I), Cu2Mo6Br14 (II) und Cu2Mo6I14 (III) wurden durch thermische Behandlung der Gemenge der binären Halogenide CuX und Mo6X12 im molaren Verhältnis 2:1 in einkristalliner Form erhalten. Röntgenographische Strukturbestimmung wurde an Einkristallen durchgeführt. I und II zeigen Isotypie, Pn3 (Nr. 201, sec. setting) Z = 4, I: a = 12,772(3) Å, II: a = 13,350(2) Å. III weist eigenen Strukturtyp auf: Pbca (Nr. 61), Z = 4, a = 16,058(3) Å, b = 10,643(2) Å, c = 16,963(3) Å. In I—III liegen trigonal planare CuX3-Gruppen vor. Bindungsverhältnisse und Meßergebnisse der Ionenleitfähigkeit werden diskutiert.
    Additional Material: 6 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 597 (1991), S. 151-161 
    ISSN: 0044-2313
    Keywords: Silver lead oxybromide ; crystal structure ; layer structure ; crystal chemistry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: AgPbOBr  -  a New Sillén Type? Preparation and Crystal StructureAgPbOBr was prepared for the first time. Its crystal structure was explored by single crystal X-ray diffraction. AgPbOBr crystallizes with tetragonal symmetry in space group P 4/nmm - No. 129 with a = 3.891(1) Å, c = 11.07(1) Å and two formulas per unit cell. Least squares refinement yields an weighted R-value of 0.065. AgPbOBr shows a layered structure with components of the crystal structure of red PbO as well as AgBr. Emphasized differences between the crystal structures of AgPbOBr and the X2-types after Sillén's notation [1] are characteristic. AgPbOBr is the first member of a new structure type, arranged between Sillén- and Aurivilliusphases [2].
    Notes: AgPbOBr wurde erstmalig dargestellt und die Kristallstruktur an Einkristallen aufgeklärt. Es kristallisiert tetragonal (Raumgruppe P4/nmm  -  No. 129) mit a = 3,891(1) Å, c = 11,07(1) Å und z = 2. Die Verfeinerung (LSQ) der Einkristallmessung liefert Rw = 0,065. AgPbOBr ist schichtförmig aufgebaut mit aus PbO und AgBr bestehenden Bereichen, die nahezu unverändert dem Bau von PbO und AgBr gleichen. Die Unterschiede zur Kristallstruktur der Sillén-Phasen vom X2-Typ [1] sind charakteristisch. AgPbOBr nimmt kristallchemisch eine Stellung zwischen den Sillén- und den Aurivillius-Phasen [2] (z. B. BiOCl und γ-Bi2 WO6) ein.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 977-980 
    ISSN: 0044-2313
    Keywords: Mercury(II) lead(II) oxide chloride ; synthesis ; crystal structure ; structural comparison ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: HgPb2O2Cl2, a “Perforated” Lead(II) OxideSingle crystals of HgPb2O2Cl2 were grown in a HgCl2 flux by reaction of PbO with HgCl2. Crystal structure analysis by single crystal X-ray methods were carried out. HgPb2O2Cl2 crystallizes monoclinic with a = 11.788(2) Å, b = 3.910(1) Å, c = 7.749(2) Å, β = 122.64(3)°, space group C2/m (No. 12) and Z = 2. HgPb2O2Cl2 is the first member of a new structure type, closely related to the structure of PbO.
    Notes: Einkristalle von HgPb2O2Cl2 wurden durch Umsetzung von PbO und HgCl2 in HgCl2-Schmelzen gezüchtet. An ihnen wurde der Aufbau mittels Einkristallröntgenstrukturanalyse bestimmt. HgPb2O2Cl2 kristallisiert monoklin mit a = 11,788(2) Å, b = 3,910(1) Å, c = 7,749(2) Å, β = 122,64(3)°, Raumgruppe C2/m (Nr. 12) und Z = 2. HgPb2O2Cl2 ist der erste Vertreter eines neuen Strukturtyps, der kristallchemisch von der Struktur von PbO ableitbar ist.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 145 (1990), S. 465-471 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Diacylglycerols (OAG, diC8) and PMA were found to stimulate fluid pinocytosis (net uptake of FITC-dextran) to a far greater extent than other neutrophil activators, such as the chemotactic agents fNLPNTL and LTB4, the microtubule disassembling agents colchicine and nocodazole, the kinase inhibitor H-7, or D2O. OAG and diC8 produce a dose-dependent increase in the uptake of FITC-dextran, which is up to about 25- to 30-fold the control value of unstimulated neutrophils. The protein kinase inhibitor H-7 alone had a small stimulating effect on the net uptake, and it failed to inhibit stimulation of fluid pinocytosis by PMA, OAG, and diC8. Also, the protein kinase inhibitor staurosporine failed to inhibit fluid pinocytosis stimulated by OAG, diC8, and PMA. Stimulated fluid pinocytosis and vacuolization in response to PMA or diacylglycerols is associated with surface ruffling of neutrophils. Pinocytosis as well as surface ruffling stimulated by PMA, OAG, diC8, or diC10 are suppressed in the presence of cytochalasin D. The results suggest that diacylglycerols may be instrumental in transducing the signal for stimulated pinocytosis and that the surface movements induced by diacylglycerols, and PMA may be instrumental in fluid pinocytosis.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 603 (1991), S. 69-76 
    ISSN: 0044-2313
    Keywords: Dicesium mercury(II) palladium(II) hexachloride ; preparation ; crystal structure ; group-subgroup relation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of Cs2HgPdCl6, a Distorted Variant of ChloroperovskitsCs2HgPdCl6 single crystals show tetragonal symmetry with the space group I 4/m m m (No. 139) with 2 formular units per unit cell. The lattice parameters are a = 7.432(4) Å, c = 10.874(7) Å. The atomic arrangement of Cs2HgPdCl6 is explored by X-ray crystal structure analysis. The important polyhedrons are square-planar PdCl4 groups and HgCl2 dumbbells. The PdCl4 group is completed by two further chlorine atoms to a elongated octahedron and four further chlorine atoms form with the HgCl2 dumbbell a compressed octahedron. The crystal structure of Cs2HgPdCl6 is compared with the arrangement in halogenoperovskits and in Rb2PdCl4 [3].
    Notes: Die Verbindung Cs2HgIIPdIICl6 läßt sich durch Festkörperreaktion phasenrein darstellen. Sie kristallisiert in der Raumgruppe I 4/m m m (No. 139) mit a = 7,432(4) Å, c = 10,874(7) Å, Z = 2. Die Kristallstruktur wurde mit röntgenographischen Methoden an Einkristallen ermittelt. Pd2+ ist quadratisch-planar und Hg2+ hantelförmig von Cl-umgeben. In zweiter Nachbarschaft ergänzen weitere Cl- zu gestreckten bzw. gestauchten Oktaedern. Dieses Bauprinzip entspricht dem Aufbau von Cs2AuIAuIIICl6 [1, 2]. Es besteht direkte kristallchemische Beziehung zur Kristallstruktur der Halogenoperowskite bzw. des K2PdCl4-Typs.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 1231-1235 
    ISSN: 0044-2313
    Keywords: Dilead(II)-hexahalogenopalladate(II) ; crystal structure ; strongly elongated PdX6 octahedra ; DTA, IR/RAMAN, 207Pb MAS NMR ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pb2PdX6 (X = Cl, Br) - Compounds with Elongated [PdX6] OctahedraIn contradiction to published data new compounds in the systems PbX2 - PdX2 (X = Cl, Br) with the formula Pb2PdCl6 (I) and Pb2PdBr6 (II) were found. These were synthesized by thermal treatment of the corresponding mixtures of PbX2 and PdX2 (X = Cl, Br). X-ray single crystal structure analysis shows isotypism of I and II, monoclinic, P21/c (No. 14), Z = 2, I: a = 9.037(2) Å, b = 6.224(1) Å, c = 8.162(1) Å, β = 90.31(7)β, II: a = 9.512(7) Å, b = 6.584(8) Å, c = 8.383(3) Å, β = 90.07(5)º. Strongly elongated PdX6 octahedra are found in the crystal structure. Additional characterisation of the compounds was done by DTA, IR/RAMAN spectra and 207Pb MAS NMR investigations. Remarcable low field shifts were found for 207Pb.
    Notes: Entgegen Literaturangaben wurden in den Systemen PbX2 - PdX2 (X = Cl, Br) die neuen Verbindungen Pb2PdCl6(I) und Pb2PdBr6(II) aufgefunden. Sie wurden durch thermische Behandlung der binären Halogenide PbX2 und PdX2 im molaren Verhältnis 2:1 dargestellt (Einkristalle). Die Kristallstrukturen wurden mit Einkristallröntgenuntersuchungen ermittelt. I und II sind isotyp, monoklin, P21/c (Nr. 14), Z = 2, I: a = 9,037(2) Å, b = 6,224(1) Å, c = 8,162(1) Å, β = 90,31(7)º, II: a = 9,512(7) Å, b = 6,584(8) Å, c = 8,383(3) Å, β = 90,07(5)º. In Pb2PdX6 werden stark gestreckte PdX6-Oktaeder beobachtet. Die Verbindungen wurden außerdem mittels DTA, IR/RAMAN-Spektren und 207Pb-MAS-NMR-Untersuchungen charakterisiert. Für 207Pb wurde eine bemerkenswerte Tieffeldverschiebung beobachtet.
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