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  • 1
    Electronic Resource
    Electronic Resource
    Cell degeneration and elimination in the imaginal wing disc, caused by the mutationsvestigial andUltravestigial ofDrosophila melanogaster (1983)
    Springer
    Development genes and evolution 192 (1983), S. 285-294 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Cell degeneration ; Imaginal disc ; Basal lamina ; Blood cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mutationsvestigial (vg; recessive) andUltravestigial (vg U; dominant) ofDrosophila melanogaster give rise to identical mutant adult phenotypes in which much of the cases this results from cell death in the presumptive wing margin of the wing disc in the third larval instar, but the process of cell degeneration is quite different in the two mutants. Invg cell death occurs continuously throughout the third larval instar, while invg U it occurs only in the early third instar. Cells fragment and some of the fragments condense, becoming electron dense (“apoptosis”). Both condensed and ultrastructurally normal cell fragments are extruded to the basal side of thevg disc epithelium. They accumulate under the basal lamina in the wing pouch area until they are phagocytosed by blood cells entering the wing pouch during the six hours following pupariation. Fragments are not extruded from thevg U epithelium but are apparently phagocytosed by neighboring epithelial cells. The basal lamina undergoes mophological changes following pupariation and is phagocytosed by blood cells in both wild-type andvestigial, but investigial the degenerated cell fragments are also engulfed by the same blood cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848662
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  • 2
    Electronic Resource
    Electronic Resource
    The effects of X-rays on the proliferation dynamics of cells in the imaginal wing disc ofDrosophila melanogaster (1977)
    Springer
    Development genes and evolution 183 (1977), S. 85-100 
    Details
    ISSN: 1432-041X
    Keywords: Pattern regulation ; Cell death ; Drosophila ; Imaginal discs ; Clonal analysis ; Mitotic recombination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We report on the size distribution of clones marked by mitotic recombination induced by several different doses of X-rays applied to 72 h oldDrosophila larvae. The results indicate that the radiation significantly reduces the number of cells which undergo normal proliferation in the imaginal wing disc. We estimate that 1000 r reduces by 40–60% the number of cells capable of making a normal contribution to the development of the adult wing. Part of this reduction is due to severe curtailment in the proliferative ability of cells which nevertheless remain capable of adult differentiation; this effect is possibly due to radiation-induced aneuploidy. Cytological evidence suggests that immediate cell death also occurs as a result of radiation doses as low as 100 r. The surviving cells are stimulated to undergo additional proliferation in response to the X-ray damage so that the result is the differentiation of a normal wing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848779
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  • 3
    Electronic Resource
    Electronic Resource
    Uptake and retention of3H-estradiol by gonadotrophs and lactotrophs in the pituitary glands of the guinea pig, hamster and gerbil (1987)
    Springer
    Cell & tissue research 248 (1987), S. 75-78 
    Details
    ISSN: 1432-0878
    Keywords: LH-cells ; Prolactin cells ; Immunocytochemistry ; Estrogen ; Autoradiography ; Guinea pig ; Hamster ; Gerbil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nuclear uptake and retention of3H-estradiol by luteinizing hormone (LH) and prolactin (PRL) cells was examined in three species of rodents (guinea pigs, hamsters and gerbils) using the combined techniques of immunocyto-chemistry and autoradiography. Castrated animals were injected with3H-estradiol and decapitated 1.5 h later. The pituitary glands were processed for thaw-mount autoradiography followed by conventional immunocytochemical staining for LH and PRL.3H-estradiol accumulated in more than 80% of the anterior pituitary cells in the gerbils, while only 33 and 22% of the cells accumulated3H-estradiol in the hamsters and guinea pigs, respectively. A varying percentage of immunoreactive LH and PRL cells in all three species were found also to contain binding sites for estradiol. Some LH and PRL cells in hamsters and guinea pigs and only some in PRL cells of gerbils were found to be devoid of grains. Quantitative analysis revealed that the number of grains per nucleus differed considerably from cell to cell. LH cells of guinea pigs accumulated much larger amounts of3H-estradiol than did the PRL cells, while the LH cells in the hamsters and gerbils accumulated only slightly more3H-estradiol than the PRL cells. These results confirm the previous observations in rats and baboons that demonstrated tremendous species differences in percentage of cells in the anterior pituitary gland that accumulated3H-estradiol. Also, these data suggest that there are functionally heterogeneous cell types among the LH and PRL cells in hamsters, guinea pigs and gerbils as has been previously demonstrated in rats and baboons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01239965
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  • 4
    Electronic Resource
    Electronic Resource
    What is Drosophila Telling Us About Cancer? (1999)
    Springer
    Cancer and metastasis reviews 18 (1999), S. 295-311 
    Details
    ISSN: 1573-7233
    Keywords: Cancer ; Drosophila ; tumour suppressor gene ; lgl ; dlg ; cytoskeleton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In Drosophila, genetic loss of the tumour suppressor protein Dlg (in dlg mutants) or p127 (in lgl mutants) leads to loss of epithelial structure and excess proliferation in the imaginal discs and brain of the developing larva. These phenotypes show most of the characteristic features of human neoplasia, so study of the gene products may contribute to our understanding of cancer. Both proteins occur in high molecular-mass complexes in the membrane-associated cytoskeleton, and they both appear to play dual roles as structural proteins and active partners in signal transduction. Dlg is a membrane-associated guanylate kinase homolog (MAGUK) found at septate junctions between epithelial cells, as well as at neuromuscular junctions. Specific domains of the protein are required for membrane targeting and for localisation in junctions, and for epithelial cell proliferation control; all of these functions are probably mediated through binding to other proteins. Loss of Dlg results in the absence of septate junctions, delocalisation of several proteins including Fasciclin III, Coracle, actin and tubulin, and loss of cell polarity. p127, although mostly associated with the plasma membrane, is in most cell types also present in the cytoplasm. It shows a dynamic subcellular distribution, and its cytosolic and membrane-associated forms play distinctive roles by interacting with different binding partners, in particular the non-muscle myosin II heavy chain. Defects associated with the lgl temperature-sensitive allele include loss of the columnar organisation of epithelial cells, indicating that p127 contributes to cell structure, presumably by stabilising the plasma membrane. In addition to their organising functions, both Dlg and p127 appear to be involved in signal transduction pathways. Study of these genes shows that some proteins play both structural and functional roles, and that cancer can involve changes in the organisation of signalling pathways in addition to changes in individual pathway components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006381526008
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  • 5
    Electronic Resource
    Electronic Resource
    Spectrophotometric and Nuclear Magnetic Resonance Study of Temperature- and Pressure-induced Changes in the Intimate Solvation of Neodymium (III) in N, N-Dimethylformamide and Trimethylphosphate (1982)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 65 (1982), S. 1025-1028 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The temperature- and pressure-dependent equilibria for the addition of an extra N, N-dimethylforrnamide (DMF) or trimethylphosphate (TMP) ligand onto [Nd (DMF)8]3+- and [Nd(TMP)6]3+-species respectively have been measured by visible spectrophotometry. Complementary NMR. studies on other lanthanide ions show a gradual shift in preference for the lower coordination number across the lanthanide series.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19820650333
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis of Linear Oligomers of (R)-3-Hydroxybutyrate and Solid-State Structural Investigations by electron microscopy and X-ray scatteringDedicated to Prof. Dr. H. Ringsdorf on the occasion of his 65th birthday (1994)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 77 (1994), S. 1099-1123 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Repetitive treatment of the biopolymer P(3-HB) (molecular weight 〉 105 Dalton, storage or s-P(3-HB)), with lithium hexamethyl disilazanid (LHMDS) at -70° in THF leads to a mixture of oligomers with increasingly sharp distribution around a 15-, 30-, and 45mer. Discrete fragments are also isolated when P(3-HB) is heated under reflux (89°) in neat Et3N. Linear oligo(3-HB) derivatives (3-7) containing up to 96 3-HB units are synthesized using an exponential segment-coupling strategy. These oligomers are used to calibrate size-exclusion chromatography columns for the analysis of oligo(3-HB) samples from the different sources. The linear oligo-(3-HB) derivatives also served as a model with respect to the physical properties of high molecular weight P(3-HB) and were investigated as such by transmission electron microscopy (TEM) and by small- and wide-angle X-ray scattering (SAXS and WAXS). The thicknesses of the lamellar crystallites (long periods) formed by the 8mer, 16mer, and 32mer, are ca. 26, 52, and 53 Å, respectively, indicating that the 32mer molecules are folded once, very tightly, into a ‘hair-pin’-type conformation. High-molecular-weight P(3-HB), which was crystallized in a similar way, also has a lamellar crystallite thickness of ca. 50-65 Å. Thus, the treatment of P(3-HB) with LHMDS at low temperature causes etching of the amorphous regions, an effect well known in polymer science for studying the regularity of chain folding. The ca. 50-Å packing within the tight folds of P(3-HB) is discussed in view of its possible function in ion transport through cell membranes.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19940770423
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  • 7
    Electronic Resource
    Electronic Resource
    High-Pressure Stopped-Flow Study of the Kinetics of Base Hydrolysis of the Dichromate Ion by Hydroxide Ion, Ammonia, Water, and 2,6-Lutidine in Aqueous Solution (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 2445-2448 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Volumes of activation for the base hydrolysis of the dichromate anion have been measured at 298.2 K, using high-pressure stopped-flow spectrophotometry. The values of ΔV* (cm3 · mol-1), - 17.9 ± 0.6, - 19.2 ± 0.9, - 24.9 ± 0.9 and - 26.0 ± 0.7 for OH-, NH3, H2O and 2,6-lutidine, respectively, are consistent with an interchange mechanism with associative activation mode (Ia).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660809
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  • 8
    Electronic Resource
    Electronic Resource
    Dendrimers with Porphyrin Cores: Synthetic models for globular heme proteins (1997)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 80 (1997), S. 1773-1801 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dendritic iron porphyrins were synthesized as functional mimics of globular electron-transfer heme proteins. The cascade molecules 1 · Zn-3 Zn of first to third generation were obtained starting from the (meso-diarylporphyrin) zinc 6 · Zn which contains four carboxylate arms for attachment of the poly(ether-amide) dendritic branches by peptide-coupling methodology (Scheme 1). Generation 3 compound 3 · Zn with 108 methyl-carboxylate end groups has a molecular weight of 19054. D, and computer modeling suggests that its structure is globular and densely-packed, measuring ca. 4 nm in diameter and, therefore, similar in dimensions to the electron-transfer protein cytochrome-c. Starting from the generation 1 poly(carboxylic acid) 11 · Zn and the generation 2 analog 12 · Zn the dendritic ZnII porphyrins 4 · Zn and 5 · Zn, respectively, were obtained by esterification with triethyleneglycol monomethyl ether (Schemes 3 and 4). Demetallation followed by insertion of FeII and in situ oxidation afforded the water-soluble dendritic iron porphyrins 4 FeCl and 5 FeCl. The electrochemical behavior of esters 1 · Zn-3 · Zn in organic solvents changed smoothly with increasing dendritic generation (Table 1). Progressing from 1 · Zn to 3 · Zn in THF, the first porphyrin-centered oxidation and reduction potentials become more negative by 320 and 210mV, respectively. These changes were attributed to strong microenvironmental effects imposed on the electroactive core by the densely packed dendritic surroundings. The electrochemical properties of 4 · FeCl and 5 · FeCl were investigated by cyclic voltammetry in both CH2Cl2 and H2O (Tables 2 and 3). Progressing from 4 · FeCl to 5 · FeCl in CH2Cl2, the redox potential of the biologically relevant FeIII/FeII couple remained virtually unchanged, whereas in aqueous solution, 5 FeCl exhibited a potential 420 mV more positive than did 4 FeCl. The large difference between these potentials in H2O was attributed to differences in solvation of the core electrophore. Whereas the relatively open dendritic branches in 4 · Fecl do not impede access of bulk solvent to the central core, the densely packed dendritic superstructure of 5 · FeCl significantly reduces contact between the heme and external solvent. As a result, the more charged FeIII state is destabilized relative to FeII, and the redox potential is strongly shifted to a more positive value.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19970800603
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  • 9
    Electronic Resource
    Electronic Resource
    Enantioselective pharmacodynamics of the nonsteroidal antiinflammatory drug ketoprofen: In vitro inhibition of human platelet cyclooxygenase activity (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 4 (1992), S. 484-487 
    Details
    ISSN: 0899-0042
    Keywords: ketoprofen enantiomers ; thromboxane ; in vitro activity ; 2-arylpropanoic acids ; sigmoidal Emax modelling ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pharmacological activity of ketoprofen enantiomers was investigated in humans by an in vitro method. The antiplatelet effect of ketoprofen was assessed by measuring the inhibition of platelet thromboxane B2 (TXB2) generation during the controlled clotting of whole blood obtained from each of four healthy volunteers. Ketoprofen was added separately to whole blood as a range of concentrations of (1) predominantly (S)-ketoprofen, (2) racemic ketoprofen, and (3) predominantly (R)-ketoprofen. (S)-Ketoprofen was found to be solely active at inhibiting human platelet TXB2 production; (R)-ketoprofen was devoid of such activity and did not modify the potency of its optical antipode. A relationship between the percentage inhibition of TXB2 generation and the unbound concentration of (S)-ketoprofen in serum was modelled according to a sigmoidal Emax equation. The mean (±SD) serum unbound concentration of (S)-ketoprofen required to inhibit platelet TXB2 generation by 50% (EC50) was 0.320 (±0.062) ng/ml. This value for ketoprofen is considerably lower than previously reported values for (S)-ibuprofen and (S)-naproxen. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chir.530040805
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  • 10
    Electronic Resource
    Electronic Resource
    Stereoselective analysis of ketorolac in human plasma by high-performance liquid chromatography (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 5 (1993), S. 31-35 
    Details
    ISSN: 0899-0042
    Keywords: ketorolac enantiomers ; HPLC ; plasma concentrations ; nonnarcotic analgesic ; nonopiate analgesic ; diastereomers ; nonsteroidal antiinflammatory drugs (NSAIDs) ; stereoselective pharmacokinetics ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A high-performance liquid chromatographic (HPLC) analytical method is described for the quantification of the (R)- and (S)-enantiomers of ketorolac when present together in human plasma. The method involves derivatization with thionyl chloride/(S)-1-phenylethylamine and subsequent reversed-phase chromatography of the diastereomeric (S)-1-phenylethylamides of (R)- and (S)-ketorolac. The method is suitable for the analysis of large numbers of plasma samples and has been applied in this report to a pharmacokinetic study of ketorolac enantiomers upon intramuscular administration of racemic drug to a human subject. The limit of quantification for each enantiomer of ketorolac is 50 ng/ml (signal-to-noise ratio 〉 10). © 1993 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chir.530050107
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