bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of infant irritability on maternal sensitivity in a sample of very premature infants
Authors: Meier Petra , Wolke Dieter , Gutbrod Tina , Rust Libi
Published: April 2003

The relationship between maternal sensitivity and infant irritability was investigated in a short‐term longitudinal study of 29 very preterm infants. Infant irritability was assessed at term with the Brazelton NBAS, the Mother and Baby Scales (MABS) and the Crying Pattern Questionnaire (CPQ). Maternal sensitivity was assessed by nurses' ratings in the neonatal care unit and at three months during mother–infant interaction observation. Cross‐lagged panel analysis indicated that neonatal irritability did not influence sensitivity at 3 months nor did maternal sensitivity in the newborn period lead to reduced irritability at 3 months. Both irritability and maternal sensitivity showed moderate stability over time (r = 0.55 and r = 0.60, respectively). It is concluded that in early infancy maternal sensitivity shows little influence on infant irritability in very preterm infants. Copyright © 2003 John Wiley & Sons, Ltd.
Placental transfer of naturally acquired, maternal cytomegalovirus antibodies in term and preterm neonates
Authors: Mussi‐Pinhata Marisa Márcia , Gomes Pinto Patrícia Cristina , Yamamoto Aparecida Yulie , Berencsi Klara , de Souza Cleonice Barbosa Sandoval , Andrea Mauro , Duarte Geraldo , Jorge Salim Moyses
Published: April 2003

Maternal antibodies may protect the fetus and neonate against severe forms of CMV‐caused disease, therefore this study investigated the efficiency of the placental transfer of naturally acquired, maternal total anti‐cytomegalovirus (CMV) IgG and neutralizing antibodies at different gestational ages. The study was conducted on 182 healthy CMV‐seropositive Brazilian mothers and their 196 infants who were not infected congenitally with CMV, as determined by CMV detection in urine. The study groups were composed of 44 infants aged 28–30 weeks; 51 infants aged 31–33 weeks; 62 infants aged 34–36 weeks, and 39 infants of gestational age ≥37 weeks. Quantitative detection of total CMV IgG was carried out using EIA and virus neutralizing titers were determined by a microneutralization assay in sera from mothers and infants. CMV IgG levels and neutralizing titers of the infants correlated with maternal levels (r = 0.873 and r = 0.841, respectively). The efficiency of placental transfer of these antibodies was enhanced significantly as gestation progressed until 34–36 weeks, when values similar to those of full‐term infants (90–100%) were found. Transfer ratios were significantly higher for neutralizing compared to total CMV IgG antibodies at gestational age 31–33 weeks (100% vs. 84%, respectively) and at gestational age 28–30 weeks (75% vs. 60%, respectively). We conclude that placental transfer of naturally acquired maternal CMV neutralizing and total CMV IgG antibodies are similarly efficient above 34 weeks of gestational age. At less than 34 weeks of gestational age, transfer of neutralizing antibodies may be favored and these antibodies reach the neonatal serum of 99% of these premature infants. J. Med. Virol. 69:232–239, 2003. © 2003 Wiley‐Liss, Inc.
Reaction Mechanism of Enzymatic Degradation of Poly(butylene succinate‐co‐terephthalate) (PBST) with a Lipase Originated from Pseudomonas cepacia
Authors: Honda Nozomi , Taniguchi Ikuo , Miyamoto Matsatoshi , Kimura Yoshiharu
Published: April 2003

An aliphatic/aromatic copolyester, poly(butylene succinate‐co‐terephthalate) (PBST), was prepared to investigate the effect of the aromatic units on the enzymatic degradation of the poly(butylene succinate) (PBS) derivatives in the presence of a lipase originated from Pseudomonas cepacia (Lipase PS®). The degradability of PBST was found to increase with increasing BS content. The degradation products were analyzed in detail by liquid chromatograph mass spectrometry (LC‐MS). A hexamer containing one terephthalate unit was the largest fragment among the diverse fragments detected, while a pentamer was the largest one consisting only of succinate units. The oligomeric fragments cut out from the polymer chain were involved in the secondary hydrolysis into 4‐hydroxybutyl succinate (BSH) and terephthalate (BTH). The trimeric fragments tetramethyl disuccinate (SBSH) and succinate terephthalate (SBTH), having both carboxyl end groups, were slowly hydrolyzed by a nonspecific mechanism. Based on these data, the overall mechanism of the enzymatic hydrolysis of this aliphatic/aromatic copolyester is proposed, in which PBST undergoes endo hydrolysis.

A plausible mechanism of enzymatic hydrolysis of PBST with Lipase PS®.

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A plausible mechanism of enzymatic hydrolysis of PBST with Lipase PS®.
UV/Visible Study of the Reaction of Oxidoreductases and Model Compounds with H2O2
Authors: Ferreira María Luján
Published: April 2003

Oxidative dehydrogenation/polymerization of aromatic compounds such as phenol or aniline and derivatives has been reported using a peroxidase‐H2O2 system. In the search for alternatives for expensive peroxidase, it is important to provide similar advantages to those of HRP while decreasing the catalyst cost. Knowledge of the mechanism details is important for achieving this objective. UV/Visible studies are useful to study mechanistic details and electronic changes in the compounds. These data are reported for the reaction of Catalase from Aspergillus Niger (CAP), Peroxidase from Horseradish (HRPC), Hematin and 2,6‐bis[1‐2,6‐diisopropylphenyliminoethyl]pyridine iron(II) chloride (FeB) with H2O2. Detailed spectral analysis reveals differences for Catalase, Peroxidase, and model compounds in the presence of H2O2. The possibility of hematin or FeB‐H2O2 as models for the peroxidase‐H2O2 reaction is discussed. The published mechanisms for the peroxidase‐H2O2 and Catalase‐H2O2 reactions are analyzed. The results are discussed taking into account theoretical studies on some key aspects of the mechanism.

UV/Visible spectra of CAP (Catalase concentration 72.4 U/mL).

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UV/Visible spectra of CAP (Catalase concentration 72.4 U/mL).
Preparation and investigation of optically active polyesters from α‐ethyl‐α‐phenyl‐β‐propiolactone, 1
Authors: Carrière François J. , Eisenbach Claus D.
Published: April 2003

α‐Ethyl‐α‐phenyl‐β‐propiolactone (7) of an optical purity up to 95% was prepared; the resolution of the two optical antipodes was carried out with the optical active precursor ethyl 2‐aminomethyl‐2‐phenylbutyrate (5), and the optical purity was determined by 1H NMR analysis using europium salt shift reagents. The solution and thermal properties of the corresponding polyesters 8, as obtained by anionic ring opening polymerization, were investigated. It was found that the inherent viscosity increased with the optical purity of the lactone. Distinct differences in the melting behaviour were found between the racemic and the optically active polymers; the ideal melting temperature TM0 for the pure enantiomeric polymer was estimated to about 535 K.
Polymères à propriétés pharmacologiques potentiels: greffage par liaison amide et (ou) ester d'un hypoglycémiant
Authors: Friedmann Gilbert , Aichaoui Hocine , Brini Mathilde
Published: April 2003

N‐(4‐aminobenzenesulfonyl)‐N′‐butylurea (8) (glibutamide®) and several amino compounds were grafted on water soluble and non‐toxic polymeric backbones, with the intention to study the influence of such a carrier on the hypoglycemic effects of the drug, covalently linked by ester and (or) amide bonds. The spacer by which the drug was fixed to the polymeric carrier contained 1 to 10 atoms. So far, the hypoglycemic effect of only one polymer (13d) was tested. It showed, however, negative results probably due to the amide bond of the drug which is difficult to split off.
Exchange equilibria on anion resins, 2. Effect of chemical structure of functional groups in macroporous polystyrene resins
Authors: Góźdź Antoni S. , Kolarz Bożena N.
Published: April 2003

Anion exchange equilibria were studied by the batch technique on macroporous polystyrene resins with the following functional groups: \documentclass{article}\pagestyle{empty}\begin{document}$ - \mathop {\rm N}\limits^ + {\rm H}_{\rm 2} {\rm CH}_{\rm 3} ({\rm M),} - \mathop {\rm N}\limits^ + {\rm H(CH}_{\rm 3} )_2 ({\rm DE),} - \mathop {\rm N}\limits^ + {\rm (CH}_{\rm 3} )_3 ({\rm TM),} - \mathop {\rm N}\limits^ + {\rm H}_{\rm 2} {\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm OH (E),} - \mathop {\rm N}\limits^ + {\rm H}_{\rm 2} {\rm (CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm OH)}_{\rm 2} ({\rm DE),} - \mathop {\rm N}\limits^ + {\rm (CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm OH)}_{\rm 3} ({\rm TE),} - \mathop {\rm N}\limits^ + {\rm CH}_{\rm 3} {\rm (CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm OH)}_{\rm 2} ({\rm MDE), and} - \mathop {\rm N}\limits^ + {\rm (CH}_{\rm 3} {\rm )}_{\rm 2} {\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm OH (DME)}$\end{document}. The selectivity order for these groups in slightly acidic, dilute solutions for the following anion systems: Br−/Cl−, I−/Cl−, and ClO4−/Cl− was found to be TM > DME > MDE > TE > DM > M > DE > E, but it was entirely reversed in the case of F−/Cl− system. These results are discussed in view of some known theories of ion exchange selectivity. It seems that the experimental data can be best explained in terms of the Chu‐Diamond‐Whitney theory which takes into consideration mainly changes of the water structure caused by counter‐ions, co‐ions, and functional groups of the ion exchanger.
Quaternization of poly(acrylonitrile‐co‐2‐methyl‐5‐vinylpyridine) and properties of the products in N,N‐dimethylformamide solution
Authors: Rinaudo Marguerite , Desbrieres Jacques
Published: April 2003

The kinetics of quaternization of poly(acrylonitrile‐co‐2‐methyl‐5‐vinylpyridine) (1) by methyl iodide was investigated. The rate constant k was shown to be independent of the degree of quaternization τ and the second order is valid for the reaction, independent of τ. From the dependence of k on the temperature, the thermodynamic parameters of the reaction were deduced and compared with literature data. Under the conditions to obtain τ = 1 in N‐methylpyrrolidone as solvent, a low charge polyelectrolyte was produced, soluble in DMF without decrease of the average molecular weight. The viscosimetric behaviour of the copolymer in DMF as solvent (in presence or absence of external KI salt) was studied, dependent on the charge density controlled by τ, and the ageing depends on the presence of oxygen, on the basicity of the solvent, on the degree of quaternization, and on the nature and concentration of the external salt. A mechanism is proposed, which implies the oxidation of the I− counterions to IO3−, initiating an intramolecular cyclisation of the nitrile groups.
Polymerisation via macrozwitterions, 2. Ethyl and butyl cyanoacrylates polymerised by pyridine and polyvinylpyridine
Authors: Johnston David Samuel , Pepper David Charles
Published: April 2003

Anionic polymerisations of ethyl and butyl cyanoacrylates in THF initiated by pyridine and polyvinylpyridine were studied between 42 and −95°C. The polymers showed the UV absorption of quaternised pyridine, indicating that they had grown as macrozwitterions. Pyridine consumption was very low (few %) and the polymer molecular weights high (3 · 105 – 106) irrespective of reaction conditions. Overall rates increased as reaction temperature was reduced, approaching those found in phosphine‐initiated polymerisations by −78°C. At 20°C the kinetics were complex, e.g. sigmoid conversion curves which reached an internal first order, yet showing apparent 2nd order external order. A qualitative kinetic interpretation is given, postulating absence of intrinsic termination processes, and a complex initiation process involving (exothermic) equilibrium formation of a precursor betaine. Polyvinylpyridine initiates graft copolymers; but only in presence of chain‐terminating agents, e.g. acids, lactones or sultones, can the grafted side chains be kept short, and their number raised towards the potentially complete grafting of all pyridine groups.
On the molecular weight determination by vapour pressure osmometry, 3. Relationship between diffusion coefficient of the solute and non‐colligative behaviour
Authors: Figini R. V. , Marx‐Figini M.
Published: April 2003

A recent suggestion by Bersted which takes into account the influence of the diffusion coefficient of the solute on the non‐colligative behaviour in vapour pressure osmometry is studied. Its involvement on the kind of the resulting molecular weight average is derived.
Messungen zum Aggregationsverhalten perfluorierter Alkansäuren
Authors: Hoffmann Heinz , Platz Gerhard , Rehage Heinz , Reizlein Karl , Ulbricht Werner
Published: April 2003

With the use of various techniques an attempt was made to characterize the aggregates that exist in micellar surfactant solutions of salts of the perfluornonanoic acid. The cmc values of the investigated systems were determined by conductivity and surface tension measurements. Conclusions about the shape of the micellar aggregates were drawn from rheologic and electric birefringence measurements. For the lithium, the ammonium and the tetramethylammonium surfactants the existence of normal micelles with spherical shape and with all surfactant ions lying at the micellar surface was found. The perfluornonanoate surfactants with the ammonium counterions that are partially substituted by alkyl groups showed in all investigations a behaviour that was different from the normal case. It was postulated that these solutions contain emulsion‐droplet‐like giant micelles with the surfactant ions and counterions solubilized as ion pairs in the interior of the micelles. Some of these giant micelles do not have spherical shape; these solutions showed electric birefringence. In most cases the giant micelles disappeared at higher temperatures. Only normal small micelles with spherical symmetry could then be detected and the measured values were again in the range for values of normal C8‐perfluordetergents. On the basis of the investigated systems reasons and models for the formation of giant micelles are discussed.
Intrinsic viscosity of polyelectrolytes having hydrophobic side‐residues
Authors: Miyamoto Shigeaki , Ishii Yoshiharu , Ohnuma Hiroshi
Published: April 2003

The intrinsic viscosities [η] of the alternating copolymers from isobutyl vinyl ether and maleic anhydride {p(isoBVE‐co‐MA)}, butyl vinyl ether and maleic anhydride {p(nBVE‐co‐MA)}, ethyl vinyl ether and maleic anhydride {p(EVE‐co‐MA)}, styrene and maleic anhydride {p(St‐co‐MA)}, and indene and maleic anhydride {p(indene‐co‐MA)} were determined and analysed as a function of the molecular weight M and the degree of neutralization β at various NaCl concentrations Cs. The following results were obtained: (1) [η] of the polyelectrolytes having hydrophobic side‐residues and divalent‐like carboxyl residues is very small at low charge density β = ≦ 0,2, increasing steeply with ionization until its maximum in the vicinity of β = 0,5. (2) The longrange interaction parameter Be due to the electrostatic repulsive force and the electrostatic part of the expansion factor α (which is defined by the ratio of [η] to its value at infinite ionic strength) exhibits the same behavior as [η] · (3) α can be expressed in terms of (M/Cs)1/2 in the same manner as for poly(acrylic acid), being different from the results predicted by many authors. The applicability of Fixman's theory in which Be is a linear function of \documentclass{article}\pagestyle{empty}\begin{document}$ 1/\sqrt {C_{\rm s} } $\end{document} was confirmed under consideration of the charge fraction and the bond length.
Synthesis and conformational study of poly(L‐valyl‐L‐valyl‐ϵ‐N‐benzyloxycarbonyl‐L‐lysine) in the solid state and in solution
Authors: D'Alagni Maria , Mignucci Gianfranco
Published: April 2003

High molecular weight poly(L‐valyl‐L‐valyl‐ϵ‐N‐benzyloxycarbonyl‐L‐lysine) (PVVZL) (7) was obtained by condensation in dimethyl sulfoxide of the L‐valyl‐L‐valyl‐ϵ‐N‐benzyloxycarbonyl‐L‐lysine p‐nitrophenyl ester, synthesized by the DCC

Standard abbreviations for amino acid derivatives and peptides are used according to the I.U.P.A.C.‐I.U.B. Commission on Biochemical Nomenclature, Biochemistry 11, 1726 (1972). The abbreviations used are: Boc = tert‐butyloxycarbonyl; Z = benzyloxycarbonyl; OBzl = benzyl ester; H‐Val‐OH = valine; H‐Lys‐OH = lysine; HONp = para‐nitrophenol; DDC = dicyclohexylcarbodiimide; DMSO = dimethyl sulfoxide; TFA = trifluoroacetic acid; TFE = 2,2,2‐trifluoroethanol; CD = circular dichroism; IR = infrared spectra.

method. The conformation of 7 was studied in the solid state and in solution of 2,2,2‐trifluoroethanol, acetonitrile‐trifluoroethanol and dioxane‐trifluoroethanol mixtures by X‐ray diffraction method, CD and IR spectroscopy. The results obtained in the solid state suggest the presence of β‐structure, whereas in trifluoroethanol solution, at least, a mixture of random coil and β conformation, probably occurs. The aging of the solution seems to give rise to a higher content of β‐structure. The addition of acetonitrile and dioxane favours the formation of an increasing amount of β‐structure. Therefore, the conformational behaviour of 7 is similar to that of other sequential polypeptides containing valyl residues, which seem to promote the β‐structure.
Influence of Catalyst and Polymerization Conditions on the Properties of 1,3‐Trimethylene Carbonate and ε‐Caprolactone Copolymers
Authors: Pêgo Ana Paula , Zhong Zhiyuan , Dijkstra Pieter J. , Grijpma Dirk W. , Feijen Jan
Published: April 2003

The influence of the catalyst/initiator system and polymerization conditions on the microstructure and physical properties of copolymers of equimolar amounts of 1,3‐trimethylene carbonate (TMC) and ε‐caprolactone (CL) was studied. Statistical copolymers were prepared in the presence of stannous octoate (SnOct2) in the bulk at 80 °C (14 and 28 d) and 130 °C (1 and 3 d). The copolymerization of TMC and CL initiated by yttrium isopropoxide (Y5(μ‐O)(OiPr)13) was performed in solution at room temperature (5 min) and in the bulk at 80 °C (2 min). Block copolymers, used as reference materials, were also prepared by sequential polymerization of the monomers in solution at room temperature with yttrium isopropoxide. Both SnOct2 and yttrium isopropoxide yielded polymers with shorter average monomer sequence lengths at higher reaction temperatures. For the polymerizations with SnOct2 a similar effect was observed when the reactions were allowed to proceed for longer periods of time. Independent of the catalyst/initiator system, the statistical copolymers prepared in the bulk at 80 or 130 °C were amorphous, with average monomer sequence lengths shorter than 3. The copolymer prepared in solution at room temperature with yttrium isopropoxide was more blocky, with CL sequences long enough to crystallize ($\overline {\rm L} _{{\rm CL}} = 3.93$). The former copolymers are highly flexible but show low tensile strengths, in agreement with their amorphous structure and low glass transition temperature. The latter copolymer is also flexible but much tougher and stiffer, as it is semi‐crystalline. Its properties are characteristic of phase‐separated block copolymers.

Expanded regions of carbonyl carbon atoms in 13C NMR (75.5 MHz) spectra of TMC–CL copolymer prepared at 80 °C in the bulk in the presence of yttrium isopropoxide.

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Expanded regions of carbonyl carbon atoms in 13C NMR (75.5 MHz) spectra of TMC–CL copolymer prepared at 80 °C in the bulk in the presence of yttrium isopropoxide.
Emulsion Polymerization of a Sugar Derivative–Kinetic Studies and Properties of the Sugar Latexes
Authors: Koch Ulrich , Yaacoub Emile‐Joseph
Published: April 2003

Free‐radical batch‐emulsion polymerization of 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranose (3‐MDG) initiated by a water‐soluble initiator (potassium peroxodisulfate, KPS), in the presence of an ionic emulsifier (sodium dodecyl sulfate, SDS), was investigated at 60 °C. The effect of the emulsifier and initiator concentration on the reaction kinetics and on the colloidal and molecular properties of the sugar latexes was studied. It was found that the rate of polymerization over interval II is proportional to the concentration of the initiator and the emulsifier raised to the power of 0.40 and 0.68, respectively. The particle size decreased and the number of particles increased with increasing either SDS or KPS concentration. The average value of the propagation rate constants of polymerization (kp) for 3‐MDG was found to be 257 L · mol−1 · s−1. The weight‐average molecular weights also increased with increasing the emulsifier concentration. The sugar latexes exhibit a high glass transition temperature (Tg) of 167 °C.

Effect of SDS concentration on the average number of particles (Np) and the weight‐average molecular weight (Mw).

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Effect of SDS concentration on the average number of particles (Np) and the weight‐average molecular weight (Mw).
Fluorescence of Copoly(ester‐imide)s Containing 2,6‐Naphthoate Units
Authors: Spies Cathrin , Lorenc Aleksandra , Gehrke Rainer , Kricheldorf Hans R.
Published: April 2003

The intrinsic fluorescence of copoly(ester‐imide)s is used to obtain information about the existence of sandwich like arrangement of aromatic units. The copoly(ester‐imide) investigated herein contains tert‐butylhydroquinone, N‐(4‐carboxyphenyl)trimellitimide and 2,6‐naphthoate moieties. Depending on the excitation wavelength, different sandwich like arrangements are observed by the change of the fluorescence. Identification of the different interacting units was performed by comparing the copoly(ester‐imide) fluorescence with the fluorescence of different low molecular weight model substances representing different parts of the polymer chain. Ground‐state stable dimer formation between the imide parts and the naphthoate moieties, as well as mixed ground‐state stable complex formation between these parts was observed. All measurements were performed in 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) solutions.

Comparison of copoly(ester‐imide) fluorescence with constituent model substances.

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Comparison of copoly(ester‐imide) fluorescence with constituent model substances.
Anionic Polymerization of Cyclohexa‐1,3‐diene in Cyclohexane with High Stereoregularity and the Formation of Crystalline Poly(cyclohexa‐1,3‐diene)
Authors: Quirk Roderic P. , You Fengxiang , Zhu Lei , Cheng Stephen Z. D.
Published: April 2003

Polymerization of cyclohexa‐1,3‐diene using sec‐BuLi as initiator in cyclohexane produces both soluble (70–90 wt.‐%) and insoluble (10–30 wt.‐%) fractions depending on the temperature. The insoluble poly(cyclohexa‐1,3‐diene) was crystalline as determined by X‐ray diffraction and differential scanning calorimetry analysis (Tm = 178 °C). Both fractions were characterized by size exclusion chromatography and by 1H NMR and 13C NMR spectroscopy. The microstructures of both fractions were determined by high‐resolution 1H NMR and quantitative 13C NMR spectroscopy and compared to those poly(cyclohexa‐1,3‐diene)s prepared in benzene and in cyclohexane with 1,4‐diazobicyclo[2.2.2]octane (DABCO) as additive. The amount of 1,4‐addition of the insoluble fraction in cyclohexane was ≥ 97% and the cis planomer content was higher in cyclohexane than in benzene or in cyclohexane with DABCO as additive.

DSC traces for the insoluble PCHD recrystallized from dichloroethane.

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DSC traces for the insoluble PCHD recrystallized from dichloroethane.
Alcoholysis of Methyl Aluminium Biphenoxides: Excellent Initiators for the Ring Opening Polymerisation of ε‐Caprolactone
Authors: Liao Tien‐Chi , Huang Yi‐Lun , Huang Bor‐Hunn , Lin Chu‐Chieh
Published: April 2003

Several aluminium alkoxides are prepared, and their catalytic activities toward ring‐opening polymerisation of ε‐caprolactone have been investigated. The reaction of [(μ‐EDBP)AlMe]2 (EDBP‐H2: 2,2′‐ethylidenebis(4,6‐di‐tert‐butylphenol)) with 2 molar equiv. of monomethylethylene glycol yields a five‐coordinated dimeric aluminium complex, (1). [(μ‐EDBP)AlMe]2 reacts with 2 molar equiv. of alcohol in toluene at ambient temperature to give a four‐coordinated dimeric aluminium complex, [(EDBP)Al(μ‐OR)]2 (2: R = Me; 3: R = Et; 4: R = 4‐MeOC6H4). However, the reaction of [(μ‐EDBP)AlMe]2 with 2 molar equiv. of benzhydrol in tetrahydrofuran (THF) gives a four‐coordinated monomeric complex, [(EDBP)Al(OCHPh2)(THF)] (5).

Molecular structure of 1 as 20% ellipsoids, hydrogen atoms are omitted for clarity.

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Molecular structure of 1 as 20% ellipsoids, hydrogen atoms are omitted for clarity.
Radiation‐induced crosslinking of polypotassium acrylate
Authors: Bashaw R. N. , Harper B. G.
Published: April 2003

The effects of radiation on potassium acrylate and polypotassium acrylate and their aqueous solutions have been studied. In the presence of air and at high and low water concentrations, degradation is the predominant radiation‐induced reaction. Cross‐linking occurs at intermediate concentrations. The degree of crosslinking for a given dose reaches a maximum at a polymer concentration of about 60%. An explanation of these results is presented.
Action des rayons γ du radiocobalt sur les solutions aqueuses de polyoxyethyleneglycol
Authors: Crouzet C. , Marchal J.
Published: April 2003

Nous avons etudié l'irradiation de solutions aqueuses de polyoxyèthyléneglycol à l'aide des rayons γ issus du radiocobalt. Dans une première série d'expériences les solutions ont été irradiées en présence d'air. Ces resultats montrent l'existence de deux mécanismes opposés dont l'un conduit au pontage du polymere et l'autre à la dégradation.
The infrared spectra of crystalline polysaccharides. VIII. Xylans
Authors: Marchessault R. H. , Liang C. Y.
Published: April 2003

Oriented films of 4‐O‐methylglucuronoxylan from several sources were prepared by hot stretching acetyl derivatives. The resulting oriented samples could be converted to crystalline xylans without destroying the orientation. Infrared spectra of the oriented samples were recorded using polarized radiation. Band assignments were made on the basis of empirically known group frequencies, the spectra of the deuterated analogs (OH → OD), and comparison with the spectra of small molecule model compounds. The dichroic ratios observed for the carbon hydrogen modes in the polarized spectrum along with the observed 15 A. fiber repeat of crystalline xylan “hydrate” are interpreted in terms of a threefold screw polymer conformation. Finally, by comparison of the polarized spectrum of an oriented hardwood xylan with that derived from a radial section of hardwood it was deduced that the xylan is oriented in the fiber direction in the tree.
Infrared absorption spectra and structure of polyethylene terephthalate
Authors: Tadokoro Hiroyuki , Tatsuka Kiyoaki , Murahashi Shunsuke
Published: April 2003

Highly doubly oriented specimens of polyethylene terephthalate were studied by the methods of x‐ray diffraction and of infrared microspectroscopy. The sample for the microspectroscopy was embeded in n‐butyl methacrylate resin and cut perpendicularly to the stretching direction by a microtome. The spectra by the tilting method were also taken for the measurements of the pleochroism of the intense bands. Spectral measurements at various temperatures have been also made to obtain some additional information. It was confirmed that the molecular plane of the polymer (the plane of the benzene ring) is nearly parallel to the rolled plane. The assignments of the main bands are discussed.
Auto‐Organization in Sol‐Gel Type Polycondensation: A Door to the Nanosciences
Authors: Boury Bruno , Corriu Robert
Published: April 2003

Silica‐based hybrid organic‐inorganic materials prepared by sol‐gel chemistry exhibit chemical and physical
properties revealing their anisotropic organization. Besides the opportunities that these phenomena open for the preparation of new materials,
they also provide arguments for the chemist looking for better comprehension and control of the solid's organization. © 2003 The
Japan Chemical Journal Forum and Wiley Periodicals, Inc., Chem Rec 3: 120–132; 2003: Published online in Wiley InterScience
(www.interscience.wiley.com) DOI 10.1002/tcr.10056
Nuclear factors specifically favor thyroid hormone binding to c‐ErbAα1 protein (thyroid hormone receptor α) over‐expressed in E. coli
Authors: Daadi Malika , Lenoir Christelle , Dace Alexandra , Bonne Jeannine , Teboul Michèle , Planells Richard , Torresani Janine
Published: April 2003

A recombinant rat thyroid hormone receptor α (TRα or c‐ErbAα1) was produced in E. coli as a non‐mutated,non‐fusioned protein and obtained as an efficient DNA and T3 binding protein that could be easily handled in a buffer‐soluble state (rec‐TRα). It was found that nuclear extracts (NE) added to rec‐TRα markedly amplified not only DNA binding, which has been well documented, but also T3 binding (increased binding site concentration), which has not yet been reported. This T3 binding amplifying effect on rec‐TRα occurs at low NE protein concentrations that produce no or minimal endogenous TR with respect to rec‐TR, while similar concentrations of other proteins (e.g. ovalbumin or cytosol) only moderately enhanced T3 binding. The T3 binding amplifying nuclear factors, which are partly heat‐labile, appeared as necessary auxiliaries in the analyses of partially purified rec‐TRα. A protective effect of NE against a loss of affinity for T3 under the action of antibodies directed to certain sequences in the TRα D domain suggests that nuclear factors help rec‐TRα to acquire and/or stabilize a conformation that allows the high affinity T3 binding. The nature of this nuclear amplifying factor is still unknown: RXRα which, produced in vitro, could amplify binding of the rec‐TRα to a DNA thyroid response element, was unable to display such a rescue of high affinity binding sites.
Demonstration of non‐linear detection in ELISA resulting in up to 1000‐fold too high affinities of fibronogen binding to integrin αIIbβ3
Authors: Tangemann Kirsten , Engel Jürgen
Published: April 2003

To clarify the question as to why different solid‐phase assays yield different results in terms of interaction strength, we used fibrinogen binding to immobilized αIIbβ3 integrin as a test system. A classical ‘three step’ enzyme‐linked (ELISA), a ‘two step’ biotin enzyme‐linked streptavidin and a ‘one step’ radioligand assay were compared under otherwise identical conditions. Only the last assay yielded binding constants comparable to earlier data by total internal reflection fluorescence microscopy while the other assays yielded apparent binding constants 5‐ to 1000‐fold too high. These effects are explained by non‐linearity of detection signals.
The rsp5‐domain is shared by proteins of diverse functions
Authors: Hofmann Kay , Bucher Philipp
Published: April 2003

A novel, unusually small, and highly conserved domain of modular intracellular proteins is described. The domain was first recognized as three repeats in the yeast rsp5 gene product and named thereafter. The rsp5 protein is thought to interact with nuclear proteins but also contains a C2 domain typical for cytoplasmic proteins. Further analyses revealed several additional occurrences of this domain in diverse protein classes, including cytoplasmic signal transduction proteins, gene products interacting with the transcription machinery, structural proteins like dystrophin, and a putative RNA helicase.
Two genes that encode ribosomal‐protein S6 kinase homologs are induced by cold or salinity stress in Arabidopsis thaliana
Authors: Mizoguchi Tsuyoshi , Hayashida Nobuaki , Yamaguchi-Shinozaki Kazuko , Kamada Hiroshi , Shinozaki Kazuo
Published: April 2003

We have isolated two closely related cDNA clones (cATPK19 and cATPK6) with homology to protein‐serine/threonine kinases from Arabidopsis thaliana using the polymerase chain reaction (PCR). The deduced amino acid sequences of the ATPK19 and ATPK6 contain all 11 conserved regions of the catalytic domain of protein kinases, and have homology to p70 ribosomal S6 kinases (52%). ATPK19 and ATPK6 have putative PEST regions in their N‐ and C‐terminal regions, and these regions also contain putative phosphorylation sites that are recognized by casein kinases or proline‐directed protein kinases such as cdc2, MAP kinase, and p54 MAP‐2 kinase (SAPK). The transcription levels of the ATPK19 and ATPK6 genes rapidly and markedly increased when plants were subjected to cold or high‐salt stresses. These observations suggest that ATPK19 and ATPK6 may function in the adaptation of plant cells to cold or high‐salt conditions, providing an understanding of the role of protein phosphorylation in plant responses to environmental stresses.
Induction of apoptotic DNA fragmentation and cell death by natural ceramide
Authors: Ji Li , Zhang Gu , Uematsu Shogo , Akahori Yukio , Hirabayashi Yoshio
Published: April 2003

We have found that a solvent mixture of ethanol and dodecane was able to disperse natural ceramide (Cer) into aqueous solution. In U937 cells, addition of natural Cer to medium caused a characteristic pattern of DNA fragmentation, which is indistinguishable from that caused by TNFα. The effective concentration of Cer is as low as 25 nM. The present study provides direct evidence that natural Cer functions as a second messenger mediating TNFα‐induced DNA fragmentation. The use of this solvent to deliver hydrophobic natural Cer to cells will contribute to the elucidation of the biological function of Cer.
Stoichiometry of K+/H+ antiport helps to explain extracellular pH 11 in a model epithelium
Authors: Azuma Masaaki , Harvey William R. , Wieczorek Helmut
Published: April 2003

The stoichiometry of K+/H+ antiport was measured fluorometrically by the static head method in highly purified vesicles from goblet cell apical membranes of larval lepidopteran midgut. The measured stoichiometry of 1 K+/2 H+ explains how the antiport results in electrophoretic exchange of extracellular H+ for intracellular K+, driven by the voltage component of the proton‐motive force of an H+ translocating V‐ATPase that is located in the same membrane. In turn, the exchange of K+ for H+ helps to explain how the midgut contents are alkalinized to a pH of 11.
Structural analysis of the interaction of the tRNA modifying enzymes Tgt and QueA with a substrate tRNA
Authors: Mueller Stefan O. , Slany Robert K.
Published: April 2003

The enzymes tRNA guanine‐transglycosylase (Tgt) and S‐adenosylmethionine : tRNA ribosyltransferase‐isomerase (QueA) participate in the biosynthesis of the hypermodified tRNA nucleoside queuosine (Q) in Escherichia coli. Here we show by HPLC analysis and gel retardation that both enzymes interact with an in vitro transcribed tRNAAsp from yeast, specifically modified with a Q precursor molecule. RNase I footprinting experiments showed strong protein tRNA contacts in the anticodon stem‐loop and a minor interaction with the dihydrouridine loop. This suggests that all identity elements for the recognition of Q‐specific tRNAs are clustered in the anticodon region and explains earlier results that both enzymes accept a RNA microhelix with the sequence of an anticodon stem‐loop as substrate.
The nitric oxide donors, azide and hydroxylamine, inhibit the programmed cell death of cytokine‐deprived human eosinophils
Authors: Beauvais Francis , Michel Laurence , Dubertret Louis
Published: April 2003

Azide and hydroxylamine release nitric oxide (NO) enzymatically in biological conditions. We observed that both compounds were able to inhibit in vitro the programmed cell death of human eosinophils from peripheral blood. This protective effect could be mimicked by permeable cGMP analogs and by the phosphodiesterase inhibitor 3‐isobutyl‐1‐methylxanthine. Moreover, the soluble guanylate cyclase inhibitor LY‐83583 inhibited in a dose‐response manner the effects of the NO donors. Consequently, via the increase of eosinophil survival, NO could contribute to the amplification of inflammatory and allergic processes. This effect appears to be mediated, at least in part, by the soluble guanylate pathway.
Interaction of primer tRNALys3 with the p51 subunit of human immunodeficiency virus type 1 reverse transcriptase: a possible role in enzyme activation
Authors: Zakharova Olga D. , Tarrago-Litvak Laura , Fournier Michel , Andreola Marie Line , Repkova Marina N. , Venyaminova Alija G. , Litvak Simon , Nevinsky Georgyi A.
Published: April 2003

In the interaction between HIV‐1 RT and tRNALys3 each subunit of the heterodimer interacts with tRNA showing a different affinity: K
d (p66) = 23 nM, K
d (p51) = 140 nM. Preincubation of heterodimeric RT with tRNA, at concentrations similar to that of the K
d value for p51, leads to an increase of the catalytic activity on poly(A)‐oligo(dT). These results were compared to those using different tRNA analogs: oxidized tRNA, lacking one, two or three nucleotides from the 3′‐end, or ribo‐ and deoxyribonucleotides mimicking the anticodon loop sequence. In all cases, tRNA analogs were weaker activators of HIV‐1 RT than natural tRNA. A possible mechanism of RT p66/p51 activation by tRNA and its analogs, mediated through the p51 subunit, is discussed.
DNA replication specificity of TYLCV geminivirus is mediated by the amino‐terminal 116 amino acids of the Rep protein
Authors: Jupin Isabelle , Hericourt François , Benz Bianca , Gronenborn Bruno
Published: April 2003

Geminiviruses are plant DNA viruses replicating by a rolling circle mechanism. We have investigated the specificity of replication origin recognition of two different isolates of tomato yellow leaf curl virus (TYLCV). Here, we show that TYLCV‐Sardinian and ‐Israeli replication proteins display a high degree of specificity for their respective origins. The DNA sequences recognized are located on the left part of the intergenic region whereas the amino‐terminal 116 amino acids of the Rep protein determine the specificity of origin recognition.
A primordial dopamine D1‐like adenylyl cyclase‐linked receptor from Drosophila melanogaster displaying poor affinity for benzazepines
Authors: Sugamori Kim S. , Demchyshyn Lidia L. , McConkey Fortunata , Forte Michael A. , Niznik Hyman B.
Published: April 2003

We report here the isolation from Drosophila melanogaster of a 2.0 kb cDNA clone encoding a 385 amino acid protein (dDA1) displaying, within putative transmembrane domains, highest amino acid sequence homology (49–53%) to members of the vertebrate dopamine D1‐like receptor family. When expressed in either Sf9 or COS‐7 cells, dDA1 did not bind the specific D1‐like receptor antagonist [3H]SCH‐23390 or numerous other dopaminergic, adrenergic or serotoninergic ligands with high affinity. However, like vertebrate dopamine D1‐like receptors, dDA1 stimulated the accumulation of cAMP in response to DA (EC50 ∼300 nM) and 6,7‐ADTN (EC50∼500 nM). The dopaminergic rank order of potency (DA > NE⪢5‐HT) and the lack of stimulation by other possible neurotransmitters (octopamine, tyramine, tryptamine) or DA metabolites (e.g. N‐acetyl dopamine) found in Drosophila suggests that this receptor functionally belongs to the dopamine D1‐like subfamily. Benzazepines, which characteristically bind to vertebrate dopamine D1‐like receptors with high affinity, were relatively poor in stimulating (SKF‐38393, SKF‐82526; EC50 > 10 μM) dDA1‐mediated accumulation of cAMP. Of the numerous compounds tested, a few dopaminergic antagonists inhibited DA‐stimulated production of cAMP in a concentration‐dependent manner, albeit with considerably reduced affinity, and with the rank order of potency: (+)‐butaclamol(K
b∼125nM) > SCH‐23390(K
b∼230nM) > α‐flupenthixol (K
b ∼ 400 nM) > chlorpromazine ≥ spiperone (K
b ∼ 680 nM) ≥ clozapine In situ hybridization revealed that dDA1 receptor mRNA is expressed as a maternal transcript, and at later blastoderm stages is restricted to apical regions of the cortical peripheral cytoplasm. The generation of inter‐species D1 receptor chimeras may help to identify those particular sequence‐specific motifs or amino acid residues confering high affinity benzazepine receptor interactions.
SR120819A, an orally‐active and selective neuropeptide Y Y1 receptor antagonist
Authors: Serradeil-Le Gal Claudine , Valette Gérard , Rouby Pierre-Eric , Pellet Alain , Oury-Donat Florence , Brossard Gabrielle , Lespy Liliane , Marty Eléonore , Neliat Gervais , de Cointet Paul , Maffrand Jean-Pierre , Le Fur Gérard
Published: April 2003

An orally‐active antagonist of neuropeptide Y (NPY) Y1 receptors, SR 120819A, has been characterized. This compound displays highly selective and competitive affinity for rat, guinea‐pig and human (K
i = 15 nM) NPY Y1 receptors. In vitro, SR 120819A blocks the inhibitory effect of NPY on adenylyl cyclase activity in human SK‐N‐MC cells and that of the selective Y1 agonist, [Leu31,Pro34]NPY, on rabbit vas deferens contraction (pA2 = 7.20 ± 0.07). In vivo, by intravenous route, this compound acts as an antagonist in anesthetized guinea‐pigs and, notably, after oral administration, SR 120819A counteracts the pressor response of [Leu31,Pro34]NPY (5 μg/kg i.v.) with a long duration of action (>4 h at 5 mg/kg p.o.). Thus, SR 120819A is the first orally‐effective NPY Y1 receptor antagonist yet descrobed. It could be a useful tool for exploring the role of NPY and the therapeutic relevance of an antagonist at NPY Y1 receptors.
Deficiency of ganglioside biosynthesis in metastatic human melanoma cells: relevance of CMP‐NeuAc: LacCer α2‐3 sialyltransferase (GM3 synthase)
Authors: Zebda Noureddine , Pedron Sandrine , Rebbaa Abdelhadi , Portoukalian Jacques , Berthier-Vergnes Odile
Published: April 2003

The glycosphingolipid patterns were analyzed on two clones derived from a human melanoma cell line and selected for their respectively high and low metastatic ability in immunosuppressed newborn rats. Conversely to the weakly metastatic cells which exhibited a pattern similar to that of the parental cell line, highly metastatic human melanoma cells appeared to be deficient in ganglioside biosynthesis. An accumulation of lactosylceramide was found in the latter cells, with low amounts of GM3 as the only ganglioside detected and a fourfold decreased activity of GM3 synthase (EC 2.4.99.9). After subcutaneous injection of metastatic cells in newborn rats, the cells proliferating in the tumor induced at the injection site re‐expressed the four common gangliosides of melanoma: GM3, GM2, GD3 and GD2, whereas the cells growing in the lungs as metastatic nodules were deficient in ganglioside synthesis and showed an accumulation of lactosylceramide. Taken together, our results suggest that the human melanoma cells which are able to escape from the primary tumor and invade the lungs have an impaired ganglioside biosynthesis with a deficient GM3 synthase.
Functional analysis of a newly identified TAAT‐box of the rat insulin‐II gene promoter
Authors: Leibiger Ingo B. , Schwarz Thomas , Leibiger Barbara , Walther Reinhard
Published: April 2003

Transcriptional regulation of insulin gene expression is achieved by an interplay of tissue‐specific and ubiquitous cis‐ and trans‐acting elements. E‐box like motifs and TAAT‐motifs were shown to play a crucial role in initiating insulin gene transcription. Studying the AT‐rich region of the rat insulin‐II promoter betwee nucleotides −212 and −196, we observed a base difference at −211, an adenosine instead of a cytidine, compared to the previously reported sequence (EMBL Accession No. J00748). Sequence analysis of promoter fragments from different rat strains showed that adenosine at position −211 represents the wild type (EMBL Accession No. X82162). This base exchange leads to the formation of an additional TAAT‐motif, i.e. TAAT3, at the complementary DNA strand directly upstream of the previously studied TAAT2 motif, formerly named CT‐2. Here we show that the newly identified motif TAAT3 is involved in (i) transcriptional control in vivo, (ii) in vitro DNA/protein interactions, and that (iii) TAAT1, TAAT2 and TAAT3 are binding sites for the homeodomain‐containing factor IPF‐1.
Destruction of photosystem I iron‐sulfur centers in leaves of Cucumis sativus L. by weak illumination at chilling temperatures
Authors: Sonoike Kintake , Terashima Ichiro , Iwaki Masayo , Itoh Shigeru
Published: April 2003

The activity of photosystem (PS) I in cucumber leaves was selectively inhibited by weak illumination at chilling temperatures with almost no loss of P‐700 content and PSII activity. The sites of inactivation in the reducing side of PSI were determined by EPR and flash photolysis. Measurement by EPR showed the destruction of iron‐sulfur centers, FX, FA and FB,in parallel with the loss of quantum yield of electron transfer from diaminodurene to NADP+. Flash photolysis showed the increases in the triplet states of P‐700 and antenna pigments, along with the decrease in the electron transfer from P‐700 to FA/FB. This indicates the increase in the charge recombination between P‐700+ and A0
−. It is concluded that weak‐light treatment of cucumber leaves at chilling temperature destroys FX, FA and FB and possibly A1. This gives the molecular basis for the mechanism of selective PSI photodamage that was recently reported [Sonoike and Terashima (1994) Planta 194, 287–293].
Site‐directed mutants of the β subunit of protein kinase CK2 demonstrate the important role of Pro‐58
Authors: Hinrichs María Victoria , Gatica Marta , Allende Catherine C. , Allende Jorge E.
Published: April 2003

The following amino acids of the Xenopus laevis β subunit of protein kinase CK2 (casein kinase 2) were changed to alanine: Pro‐58 (β
P→A); Asp‐59 and Glu‐60 and Glu‐61 (β
DEE→AAA); His‐151–153 (β
HHH→AAA). The last 37 amino acids of the carboxyl end were deleted (β

Δ179–215). Stimulation of CK2α catalytic subunit activity was measured with casein as substrate and the following relative activities were observed: β
P→A > β
DEE→AAA ⪢ β
WT > β
HHH→AAA ⪢ β

Δ179–215. The β
DEE→AAA and β
P→A were similar to β
WT in reducing CK2α binding to DNA but β

Δ179–215 was less active. The results indicate that both Pro‐58 and the surrounding acidic cluster play roles in dampening the activation of CK2α and that the carboxyl end of β is involved in the interaction with CK2α.
Localization of cyclic‐AMP receptors with acidosomes in Dictyostelium discoideum
Authors: Padh Harish , Tanjore Shashikala
Published: April 2003

Earlier studies have shown that in Dictyostelium discoideum, a buoyant membrane fraction contained ∼90% of the vacuolar proton pump (V‐H+‐ATPase) activity, leading to its designation acidosomes. It was proposed that acidosomes may be involved in endocytosis, specially in the acidification of endosomes. In this study we further investigated the putative function(s) of acidosomes. The findings suggest that acidosomes contain abundant receptors for cyclic AMP (CAR1) and that it may be the site for recycling of internalized receptors. Acidosomes also contain an abundance of Rab4 (Bush et al. 1994), a marker for early endosomes. By these criteria, we suggest that the acidosomes are analogous to early or recycling endosome present in mammalian cells. These findings suggest that the structure earlier defined biochemically, morphologically and immunologically as acidosomes may represent early and/or recycling endosomes in this protist.
Proton coupling is preserved in membrane‐bound chloroplast ATPase activated by high concentrations of tentoxin
Authors: Sigalat Claude , Pitard Bruno , Haraux Francis
Published: April 2003

The effect of tentoxin at high concentrations was investigated in thylakoids and proteoliposomes containing bacteriorhodopsin and CF0CF1. Venturicidin‐sensitive ATP hydrolysis, ATP‐generated ΔpH and ATP synthesis were practically 100% inhibited at 2 μM tentoxin, and restored to various extents beyond 50 μM. With respect to the native enzyme, tentoxin‐reactivated ATPase had the following properties: (i) a higher ΔpH requirement to synthetise ATP; (ii) a decreased futile proton flow through CF0CF1 (without ADP), which remains 100% blocked by ADP. It is concluded that despite its altered kinetic performances, tentoxin‐modified CF0CF1 preserves its mechanism and remains a tightly coupled proton pump.