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  • 1
    Electronic Resource
    Electronic Resource
    Calcium regulating activity of 26,27-dialkyl analogs of 1α,25-dihydroxyvitamin D3 (1992)
    Springer
    Calcified tissue international 51 (1992), S. 218-222 
    Details
    ISSN: 1432-0827
    Keywords: Bone resorption ; Osteoclast formation ; Bone Ca mobilization ; 26,27-Dialkyl-1α,25-dihydroxyvitamin ; D3-Osteopenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A series of analogs of 1α,25-dihydroxyvitamin D3[1,25(OH)2D3] with alkyl substitutions in 26- and 27-positions were tested for calcium (Ca) regulating activity. The potencies of dialkyl analogs in stimulating bone resorption in neonatal mouse calvaria cultures were the highest in 1α,25-dihydroxy-26,27-dimethylvitamin D3[1,25(OH)2-(Me)2D3], followed by 1,25(OH)2D3, 1α,25-dihydroxy-26,27-diethylvitamin D3[1,25(OH)2(Et)2D3], and 1α,25-dihydroxy-26,27-dipropylvitamin D3[1,25(OH)2(Pr)2D3] in that order. A similar order of potential regarding formation of osteoclast-like cells in mouse bone marrow cell cultures and on bone Ca mobilization with long-term vitamin D-deficient rats was observed in the same series. The relative potencies of 1,25(OH)2D3, 1,25(OH)2(Me)2D3, 1,25(OH)2(Et)2D3, and 1,25(OH)2(Pr)2D3 in competing with 1,25(OH)2D3 for binding to chick intestinal cytosol receptors were 1:1:0.16:0.036. A similar order of potential in case of intestinal Ca transport in situ was observed in the same series. The potencies of dialkyl analogs in competing with 25-hydroxy-vitamin D3 for binding to rat serum vitamin D binding protein were much lower than that of 1,25(OH)2D3. Effect of 1,25(OH)2(Me)2D3 on osteopenia in rats induced by ovariectomy and right sciatic neurotomy was higher than that of 1,25(OH)2D3. From these results, the lengthening by one carbon at 26- and 27-positions was shown to maintain the Ca regulatory activity of 1,25(OH)2D3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334550
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  • 2
    Electronic Resource
    Electronic Resource
    Calcium regulating activity of 24a-homo-24,24-difluoro-1α,25-dihydroxyvitamin D3 and 26,27-dimethyl-24,24-difluoro-1α,25-dihydroxyvitamin D3 (1993)
    Springer
    Calcified tissue international 53 (1993), S. 318-323 
    Details
    ISSN: 1432-0827
    Keywords: Bone resorption ; Osteoclast formation ; Bone Ca mobilization ; Fluoro analogs of 1,25(OH)2D3 ; Osteopenia prevention
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Two fluoro analogs of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3], 24a-homo-24,24-difluoro-1α,25-dihydroxyvitamin D3 [24aF2-homo-1,25(OH)2D3], and 26,27-dimethyl-24,24-difluoro-1α,25-dihydroxyvitamin D3 [24F2-1,25(OH)2(Me)2D3] were examined for calcium (Ca)-regulating activity. The objective of the present study was to determine whether or not fluoro substitution at 24-position would alter activities of the original compounds, that is, 26,27-dimethyl 1α, 25-dihydroxyvitamin. D3[1,25(OH)2 (Me)2D3] and 24-homo-1α,25-dihydroxyvitaminD3[24homo-1,25(OH)2D3], respectively. The relative activities of 24aF2-homo-1,25(OH)2D3, 24F2-1,25(OH)2(Me)2D3, and 1,25(OH)2D3 in competing with 1,25(OH)2D3 for binding to chick intestinal cytosol receptor were 0.28:0.5:1.0. The relative potencies of the same series of compounds in competition for the vitamin D-deficient rat serum binding sites were 0.04:0.15:1. Bone-resorbing activities of two fluoro analogs in cultures of neonatal mouse parietal bones were more potent than that of 1,25(OH)2D3. Similar results were recognized in stimulating activities of osteoclast-like cell formation. Responses of two fluoro analogs to intestinal Ca absorption were similar to that of 1,25(OH)2D3. The potencies of 1,25(OH)2D3. and its fluoro analogs in bone Ca mobilization were the highest with 1,25(OH)2D3. followed by 24F2 1,25(OH)2(Me)2D3 and 24aF2-homo-1,25(OH)2D3, in that order. From these results and the data of Paulson et al. [24], fluoro substitution in 24-position of 1,25(OH)2D3. apparently does not alter their activities, hence, the fluoro substitution at 24-position of 1,25(OH)2D3. and the elongation of side chain of 1,25(OH)2D3. may not intensify Ca-regulating activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01351836
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  • 3
    Electronic Resource
    Electronic Resource
    Binding of methyl orange and its homologs by polyion complexes consisting of a piperidinium cationic polymer and various polyanions in aqueous solution (1983)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 447-455 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A study was made of the formation of polyion complexes between a piperidinium cationic polymer and polyanions and of the binding of azo-dye anions (methyl, ethyl, propyl, and butyl orange) by these complexes. Sodium poly(acrylate), poly(styrenesulfonate), dextran sulfate, and carboxy-methylcellulose were used as polyanions. The resultant polyion complexes (insoluble in aqueous solutions) were compared for their ability to bind the small organic molecules in aqueous solutions, for example, of urea and an inorganic electrolyte (KCI), and exhibited a strong binding affinity toward these small anions. Polyion complexes that consisted of sodium poly(acrylate), dextran sulfate, and carboxymethylcellulose as polyanions cooperated in the binding, whereas the polyion complex of sodium poly(styrenesulfonate) did not. It was suggested that small organic anions interact with the polyion complexes primarily through electrostatic and hydrophobic forces.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1983.170210214
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  • 4
    Electronic Resource
    Electronic Resource
    Interaction of phenolic cosolutes with polyethylenimine (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 2073-2076 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230721
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  • 5
    Electronic Resource
    Electronic Resource
    Binding of methyl orange and its homologs by polyion complexes in aqueous solution (1981)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 3237-3246 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyion complexes of sodium poly(methacrylate) and piperidinium cationic polymers [I], which are insoluble in water and have an equal number of positive and negative charges, bind organic anions (methyl orange, ethyl orange, propyl orange, butyl orange, and pentyl orange) in aqueous solution. The strength of the binding is enhanced by an increase in the hydrophobicity of the polyion complex and the small cosolute. Moreover, strong cooperative interactions appear with increased uptake of the small molecule. Urea and an inorganic electrolyte (KCl) were examined for their effect on the binding, the amount of which is strongly suppressed by these additives. The significance of hydrophobic and electrostatic interactions which accompany the binding is described.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1981.170191217
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  • 6
    Electronic Resource
    Electronic Resource
    Effects of metal ions on the interaction between polyethylenimine and azo dyes carrying hydroxyl groups (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 255-259 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230124
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  • 7
    Electronic Resource
    Electronic Resource
    Binding of methyl orange and its homologs by polyion complex in ethylene glycol (1982)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 2231-2238 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The extent of binding of methyl orange, ethyl orange, propyl orange, and butyl orange by a polyion complex, which consists of equimolar sodium polymethacrylate and a piperidinium cationic polymer, was measured in ethylene glycol at 25, 30, and 35°C. The effects of aqueous and nonaqueous media on the binding of the dye by the polymer matrix were compared. In ethylene glycol only noncooperative binding (Langmuir type) was observed, whereas two modes of binding, noncooperative and cooperative, were involved in the aqueous environment. The first binding constants and the thermodynamic parameters associated with the binding in ethylene glycol were evaluated. The polymer matrix exhibited a higher affinity toward the dye in ethylene glycol than in water at low concentrations of free dye and bound these anionic cosolutes with different hydrophobicities but the same affinity as in ethylene glycol. These interactions are highly exothermic and characterized by relatively large negative entropy changes. Electrostatic forces are the principal contributors to the dye-polymer complex formation. The binding behavior observed in the nonaqueous solvent is reasonably accounted for in terms of disappearance of hydrophobic interactions between the dye and the polymer and an increase in electrostatic attraction between the anionic small molecule and the positively charged sites on the polyion complex.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1982.170200825
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  • 8
    Electronic Resource
    Electronic Resource
    The binding of organic anions by polyvinylpyrrolidone: Determination of intrinsic binding constant and number of binding sites by competitive binding (1984)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 185-194 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The binding of 4′-dibutylaminoazobenzene-4-sulfonate (butyl orange, BO) and 1-amino-4-methylaminoanthraquinone-2-sulfonate (AQ) by crosslinked polyvinylpyrrolidone and the competition between BO and AQ for binding sites of the polymer were examined. The equilibrium data showed competitive binding. Thus the intrinsic binding constants and the number of binding sites can be evaluated easily and precisely by competitive binding. The thermodynamic parameters that accompained the binding were calculated from the intrinsic binding constant and its temperature-dependence. The thermodynamic data for BO showed that the binding process is athermal and stabilized entirely by the entropy term. The binding of BO to the polymer is entropically favorable as a result of the operation of the hydrophobic effect. In contrast, with AQ a favorable free energy for a dye-polymer complex formation is associated with a large negative enthalpy and a small entropy. Therefore it is likely that the binding of AQ occurs by energetic forces and that the large aromatic ring of the dye contributes to the binding energy. On the average, BO and AQ can bind to the crosslinked polymer to the extent of 1 dye/ca 73 basemol in 0.1M tris-acetate buffer, pH 7.0.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1984.170220118
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  • 9
    Electronic Resource
    Electronic Resource
    Thermodynamics of binding of methyl orange by crosslinked vinylpyrrolidone-divinylbenzene copolymers: Template effect (1984)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 4035-4039 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1984.170221237
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  • 10
    Electronic Resource
    Electronic Resource
    Specific interaction between polyethylenimine and azo dyes carrying hydroxyl groups (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 37-47 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The binding of acid azo dyes having phenolic hydroxyl groups such as orange I (I), orange II (II), chrome violet (III), 4-hydroxyazobenzene-4′-sulfonate (IV), and 2,4-dihydroxyazobenzene-4′-sulfonate (V) by polyethylenimine was studied by equilibrium dialysis and spectroscopic methods. The results obtained indicate that dyes (III) and (V) with two OH groups are bound much more strongly than dyes (I), (II), and (IV) with one OH group. Also polyethylenimine is far superior to any other polymers which have been examined, including bovine serum albumin, polyvinylpyrrolidone, and poly-L-lysine, in its ability to form complexes with these dyes (III) and (V). The OH groups involved participate preferentially in complex formation with polyethylenimine. The unusual affinity of polyethylenimine for the dyes carrying OH groups is discussed.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230105
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