bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradable poly(ethylene oxide) hydrogels formed by crosslinking with tert‐butylperoxybenzoate
Authors: Emami Shahriar Hojjati , Salovey Ronald , Hogen‐Esch Thieo E.
Published: January 2003

Poly(ethylene oxide) (PEO, number‐average molecular weight: 2,000,000) was crosslinked by reaction with t‐butylperoxybenzoate in the melt. Upon swelling in water, the resulting hydrogels were acidic and suggested clear evidence of spontaneous hydrolysis that continued over periods of several weeks to give clear and low‐viscosity aqueous solutions of PEO oligomers. In contrast, in neutral media the gels did not show any signs of hydrolysis. As shown by UV, IR, and size exclusion chromatographic analysis, the PEO hydrolysis products consist of benzoic acid and hydroxyl‐ and carboxyl end‐functionalized low‐molecular‐weight PEOs. This is consistent with the acid‐catalyzed hydrolysis of acetal‐, orthoester‐, and similar end‐functionalized PEOs formed by radical coupling of various PEO radicals with benzoate, alkoxy, and other radicals. Titration of the hydrolysis mixtures indicated that the total molar amount of acid exceeds that of the maximum amount of benzoic acid produced during gel formation. However, the amount of benzoic acid equaled this maximum amount. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 520–527, 2003
Novel side‐chain liquid‐crystalline polyimide for film materials
Authors: Fan Haojun , Gu Yi , Xie Meili
Published: January 2003

A novel side‐chain liquid‐crystalline polyimide (SLCPI) was prepared via copolycondensation from 3,5‐diamino‐benzonic‐4′‐biphenyl ester, 4,4′‐diamino‐ biphenyl ether, and 3,3′,4,4′‐oxydiphthalic dianhydride. The energy‐minimized structure and liquid crystallinity of SLCPI were investigated by molecular modeling, differential scanning calorimetry (DSC), wide‐angle X‐ray scattering, and polarized optical microscopy, respectively. The results indicated that this polyimide (PI) with side‐chain mesogenic units exhibited a nematic NI phase. Because of the in situ self‐reinforcement of side‐chain mesogenic units, the improved tensile strength and modulus of PI films reached 270% and 300%, respectively. The coefficient of thermal expansion of films decreased by 40%. DSC and thermogravimetric analyses indicated that the phase‐transition temperature of SLCPI was above 240 °C, and the 5% weight‐loss temperature was above 520 °C. Moreover, copolycondensation of two diamines with dianhydride and incorporation of pendent mesogenic units diminished the regularity and symmetry of main chains; as a result, SLCPI exhibits good film processability. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 554–559, 2003
Synthesis of branched polyethylenes by the tandem catalysis of silica‐supported linked cyclopentadienyl‐amido titanium catalysts and a homogeneous dibromo nickel catalyst having a pyridylimine ligand
Authors: Musikabhumma Kittichote , Spaniol Thomas P. , Okuda Jun
Published: January 2003

The synthesis of branched polyethylenes by ethylene polymerization with new tandem catalyst systems consisting of methylaluminoxane‐preactivated linked cyclopentadienyl‐amido titanium catalysts [Ti(η5:η1‐C5Me4SiMe2NR)Cl2 (R = Me or tBu)] supported on pyridylethylsilane‐modified silica (PySTiNMe and PySTiNtBu) and homogeneous dibromo nickel catalyst having a pyridyl‐2,6‐diisopropylphenylimine ligand (PyminNiBr2) in the presence of modified methylaluminoxane was investigated. Ethylene polymerization with only PyminNiBr2 yielded a mixture of 1‐ and 2‐olefin oligomers with methyl branches [weight‐average molecular weight (Mw) ∼ 460)] with a ratio of about 1:7. By the combination of this nickel catalyst with PySTiNtBu, polyethylenes with long‐chain branches (Mw = 15,000–50,000) were produced. No incorporation of 2‐olefin oligomers was observed in the 13C NMR spectra. Unexpectedly, the combination of the nickel catalyst with PySTiNMe produced lower molecular weight polyethylenes with only methyl branches. The molecular weight distributions of branched polyethylenes obtained with both PySTiNMe and PySTiNtBu combined with the nickel catalyst were broad (weight‐average molecular weight/number‐average molecular weight < 9). Bimodal gel permeation chromatography (GPC) curves were clearly observed in the PySTiNMe system, whereas GPC curves with small shoulders in low molecular weight areas were observed for PySTiNtBu. The synthesis of branched polyethylenes with tandem catalyst systems of corresponding homogeneous titanium catalysts and the nickel catalyst was also investigated for comparison. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 528–544, 2003
Hyperbranched polyethers by ring‐opening polymerization: Contribution of activated monomer mechanism
Authors: Kubisa Przemysław
Published: January 2003

Propagation in the cationic ring‐opening polymerization of cyclic ethers involves nucleophilic attack of oxygen atoms from the monomer molecules on the cationic growing species (oxonium ions). Such a mechanism is known as the active chain‐end mechanism. If hydroxyl groups containing compounds are present in the system, oxygen atoms of HO groups may compete with cyclic ether oxygen atoms of monomer molecules in reaction with oxonium ions. At the proper conditions, this reaction may dominate, and propagation may proceed by the activated monomer mechanism, that is, by subsequent addition of protonated monomer molecules to HO terminated macromolecules. Both mechanisms may contribute to the propagation in the cationic polymerization of monomers containing both functions (i.e., cyclic ether group and hydroxyl groups) within the same molecule. In this article, the mechanism of polymerization of three‐ and four‐membered cyclic ethers containing hydroxymethyl substituents is discussed in terms of competition between two possible mechanisms of propagation that governs the structure of the products—branched polyethers containing multiple terminal hydroxymethyl groups. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 457–468, 2003
Ground‐ and excited‐states reactivity dynamics of hydrogen and helium atoms
Authors: Chattaraj P. K. , Sarkar U.
Published: January 2003

Dynamic profiles of various reactivity parameters like hardness, chemical potential, polarizability, phase volume, and electrophilicity index are studied in gaining insights into the ground‐ (n = 1) and excited‐ (n = 15) states dynamics of hydrogen and helium atoms. Pertinent time‐dependent Schrödinger equations are solved for the ground and excited states of hydrogen atom and the Rydberg state of the helium atom while a generalized nonlinear Schrödinger equation is solved for the ground state of the helium atom, all interacting with external electric fields of different frequencies and intensities. For both the atoms ground states are more stable than the corresponding excited states. Hardness and phase volume can be used as diagnostics for the chaotic ionization from the Rydberg states of those atoms. Other quantities like higher‐order harmonics also lend additional support. Dynamic variants of the maximum hardness and minimum polarizability principles are found to be operative. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Self‐reflective synergetics
Authors: Knyazeva Helena
Published: January 2003

An attempt to critically analyse the claims of the theory of self‐organization of complex systems (synergetics) to the interdisciplinary generalizations and the universal efficacy of its models is made in the paper. The grounds for transfer of synergetic models to different disciplinary fields are under discussion. It is argued that synergetics is a mental scheme or a heuristic approach to exploring the complex behaviour of systems, rather than a universal key to solving concrete scientific problems. The prospects for development and the possible future of synergetics in the coming decades are estimated. Copyright © 2002 John Wiley & Sons, Ltd.
Glucosamine‐induced insulin resistance is coupled to O‐linked glycosylation of Munc18c
Authors: Chen Guoli , Liu Ping , Thurmond Debbie C. , Elmendorf Jeffrey S.
Published: January 2003

Evidence suggests that glucosamine inhibits distal components regulating insulin‐stimulated GLUT4 translocation to the plasma membrane. Here we assessed whether key membrane docking and fusion events were targeted. Consistent with a plasma membrane‐localized effect, 3T3‐L1 adipocytes exposed to glucosamine displayed an increase in cell‐surface O‐linked glycosylation and a simultaneously impaired mobilization of GLUT4 by insulin. Analysis of syntaxin 4 and SNAP23, plasma membrane‐localized target receptor proteins (t‐SNAREs) for the GLUT4 vesicle, showed that they were not cell‐surface targets of O‐linked glycosylation. However, the syntaxin 4 binding protein, Munc18c, was targeted by O‐linked glycosylation. This occurred concomitantly with a block in insulin‐stimulated association of syntaxin 4 with its cognate GLUT4 vesicle receptor protein (v‐SNARE), VAMP2. In conclusion, our data suggest that the mechanism by which glucosamine inhibits insulin‐stimulated GLUT4 translocation involves modification of Munc18c.
Differential phosphorylation activities of CDK‐activating kinases in Arabidopsis thaliana
Authors: Shimotohno Akie , Matsubayashi Satoko , Yamaguchi Masatoshi , Uchimiya Hirofumi , Umeda Masaaki
Published: January 2003

Activation of cyclin‐dependent kinases (CDKs) requires phosphorylation of a threonine residue within the T‐loop by a CDK‐activating kinase (CAK). Here we isolated an Arabidopsis cDNA (CAK4At) whose predicted product shows a high similarity to vertebrate CDK7/p40MO15. Northern blot analysis showed that expressions of the four Arabidopsis CAKs (CAK1At–CAK4At) were not dependent on cell division. CAK2At‐ and CAK4At‐immunoprecipitates of Arabidopsis crude extract phosphorylated CDK and the carboxy‐terminal domain (CTD) of the largest subunit of RNA polymerase II with different preferences. These results suggest the existence of differential mechanisms in Arabidopsis that control CDK and CTD phosphorylation by multiple CAKs.
Involvement of acetylated tubulin in the regulation of Na+,K+‐ATPase activity in cultured astrocytes
Authors: Casale Cesar H , Previtali Gabriela , Barra Héctor S
Published: January 2003

The results presented support the view that the modulation of Na+,K+‐ATPase activity in living cells involves the association/dissociation of acetylated tubulin with the enzyme. We found that the stimulation of Na+,K+‐ATPase activity by L‐glutamate correlates with decreased acetylated tubulin quantity associated with the enzyme. The effect of L‐glutamate was abolished by the glutamate transporter inhibitor DL‐threo‐β‐hydroxyaspartate but was not affected by either specific agonists or antagonists. The effect of L‐glutamate seems to be mediated by Na+ entry resulting from glutamate transport, since the Na+ ionophore monensin produced stimulation of Na+,K+‐ATPase activity with concomitant decrease of acetylated tubulin quantity associated with the enzyme.
A motif rich in charged residues determines product specificity in isomaltulose synthase
Authors: Zhang Daohai , Li Nan , Swaminathan Kunchithapadam , Zhang Lian-Hui
Published: January 2003

Isomaltulose synthase (PalI) catalyzes hydrolysis of sucrose and formation of α‐1,6 and α‐1,1 bonds to produce isomaltulose (α‐D‐glucosylpyranosyl‐1,6‐D‐fructofranose) and small amount of trehalulose (α‐D‐glucosylpyranosyl‐1,1‐D‐fructofranose). A potential isomaltulose synthase‐specific motif (325RLDRD329), that contains a ‘DxD’ motif conserved in many glycosyltransferases, was identified based on sequence comparison with reference to the secondary structural features of PalI and homologs. Site‐directed mutagenesis analysis of the motif showed that the four charged amino acid residues (Arg325, Arg328, Asp327 and Asp329) influence the enzyme kinetics and determine the product specificity. Mutation of these four residues increased trehalulose formation by 17–61% and decreased isomaltulose by 26–67%. We conclude that the ‘RLDRD’ motif controls the product specificity of PalI.
DmsD is required for the biogenesis of DMSO reductase in Escherichia coli but not for the interaction of the DmsA signal peptide with the Tat apparatus
Authors: Ray Nicola , Oates Joanne , Turner Raymond J. , Robinson Colin
Published: January 2003

The DmsD protein is essential for the biogenesis of DMSO reductase in Escherichia coli, and binds the signal peptide of the DmsA subunit, a Tat substrate. This suggests a role as a guidance factor to target pre‐DmsA to the translocase. Here, we have analysed the export of fusion proteins in which the DmsA and TorA signal peptides are fused to green fluorescent protein. Both chimeras are efficiently exported to the periplasm in wild‐type E. coli cells and we show that their export efficiencies are essentially identical in a mutant lacking DmsD. An authentic Tat substrate, TMAO reductase, is also efficiently exported in the dmsD mutant. The data indicate that DmsD carries out a critical role in DMSO reductase biogenesis/assembly but is not required for the functioning of the DmsA signal peptide.
Cell adhesion molecule regulation of nucleocytoplasmic trafficking
Authors: Aplin Andrew E.
Published: January 2003

Cells undergo processes such as proliferation, differentiation, and survival based upon cues that they receive from their microenvironment. Extracellular matrix adhesion molecules, such as integrins and syndecans, and cell–cell adhesion molecules, including cadherins and Ig superfamily members, convey information about the environment to the cell. It is evident that cell adhesion molecules (CAMs) regulate a variety of signaling events. An emerging theme is that one level of CAM signaling control is through regulated nucleocytoplasmic distribution of molecules that either phosphorylate or co‐activate transcription factors. In this manner, CAMs control transcription events that ultimately have a strong impact on cellular processes.
Antibody response to a viral transcriptional regulator
Authors: Cerutti M.Laura , Centeno Juan M. , de Prat-Gay Gonzalo , Goldbaum Fernando A.
Published: January 2003

The E2 transcriptional activator of the human papillomavirus regulates the expression of most viral transcripts. Its binding to specific target DNA sequences involves large conformational changes in the interacting macromolecules. The high stability of the E2:DNA complex prompted us to analyze the role of macromolecular interactions and adjuvant emulsions in the appearance of conformation‐specific antibodies. We demonstrate that immunization with free or DNA‐complexed E2 emulsified in an oil‐in‐water adjuvant elicits a humoral response shifted to the recognition of discontinuous epitopes. Epitope mapping and functional analysis of the generated anti‐E2 mAbs reveals that two separate antibodies populations can be obtained: those able to form a stable ternary complex with protein and DNA, and those which recognize the DNA‐binding surface of the transcription factor, interfering with E2 binding to DNA.
Is tensegrity a unifying concept of protein folds?
Authors: Zanotti Giuseppe , Guerra Concettina
Published: January 2003

We suggest that the three‐dimensional architecture of globular proteins can be described in terms of tensegrets, i.e. structural elements that are held together through attractive and repulsive forces. Hard elements of tensegrets are represented by secondary structure elements, i.e. α‐helices and β‐strands, while the role of elastic elements is played by attractive and repulsive atomic forces. Characteristics of tensegrets is that they can auto‐assemble and that they respond to changes of tension in some part of the entire object through a deformation in another part, thus partially preserving their structure, despite their deformation. This latter property well explains both the folding process and the behavior of globular proteins under mild denaturing conditions, as revealed by the molten globule state.
Estrogen levels and estrogen receptors in patients with stress urinary incontinence and pelvic organ prolapse
Authors: Lang J.H. , Zhu L. , Sun Z.J. , Chen J.
Published: January 2003

Objectives: To investigate the histologic characteristics of tissues presumed to be the cause of urinary stress incontinence and pelvic organ prolapse. Methods: Cardinal ligament and uterosacral ligament samples were obtained from 73 women undergoing hysterectomy. The evaluation of estrogen receptors (ERs) by immunohistochemical staining was semi‐quantitative. Serum estrogen was determined by ELISA. Statistical analyses were performed by the independent‐sample t‐test and one‐way ANOVA. Results: Serum estradiol levels and ER values in the premenopausal women with pelvic organ prolapse were significantly lower than in the control group (P<0.01). A positive correlation was found between ERs and the number of postmenopausal years (P<0.01). ER values were similar in the cardinal and uterosacral ligaments. Conclusions: Serum estrogen levels and ER values are significantly lower in the uterine ligaments of premenopausal women with pelvic organ prolapse, and there was a positive correlation between ER values in the uterine ligaments and the duration of postmenopausal years. Serum estrogen levels and ER values were similar in the cardinal ligament and the uterosacral ligament.
Myocardial hypertrophy of the recipient twins in twin‐to‐twin transfusion syndrome and cerebral palsy
Authors: Hyodo H.M. , Unno N. , Masuda H. , Watanabe T. , Kozuma S. , Taketani Y.
Published: January 2003

Objectives: This study was performed to determine risk factors for cerebral palsy (CP) in monochorionic twins, especially with twin‐to‐twin transfusion syndrome (TTTS). Methods: In 33 pathologically confirmed monochorionic pregnancies, we analyzed the incidence of cardiovascular and neurological complications. Results: Seventeen cases were diagnosed as TTTS. Myocardial hypertrophy was detected in seven recipient twins of TTTS, but not found in the donor twins of TTTS or in non‐TTTS. CP developed in six out of 29 in TTTS and one out of 32 in non‐TTTS. In TTTS, all the cases with CP were seen in the recipient twins. The development of CP was significantly associated with cardiovascular complications such as myocardial hypertrophy and hydropic changes. Conclusions: Myocardial hypertrophy found in the recipient twins in TTTS seems to be a risk for developing CP later on, which may have implications in understanding the pathogenesis of CP.
Intracervical misoprostol and prostaglandin E2 for labor induction
Authors: Chang Y.‐K. , Chen W.‐H. , Yu M.‐H. , Liu H.‐S.
Published: January 2003

Objectives: To compare the safety and efficacy of misoprostol with PGE2 for induction of labor by intracervical administration. Methods: Eighty‐six women with indications for labor induction at term were randomly assigned to two groups. Each woman received either 50 μg of misoprostol or 0.5 mg of prostaglandin E2 intracervically. If labor was not initiated after 4 h, the same dose was repeated every 4 h to a maximum of 200 μg of misoprostol or 1.5 mg of PGE2 until adequate labor was achieved. Results: Forty‐three women were allocated to the misoprostol group and 43 to the prostaglandin E2 group. Misoprostol was more effective than PGE2 in producing cervical changes (P<0.025). Delivery within 12 h after the first administration occurred more often in the misoprostol group than in the PGE2 one (85% vs. 56%, P<0.05). Less patients in the misoprostol group required oxytocin augmentation than in the PGE2 one (16.3% vs. 39.5%, P<0.05). Uterine tachysystole and hyperstimulation occurred more frequently in the misoprostol group (44.1%) than in the PGE2 group (18.7%) (P<0.05). Nevertheless, no statistically significant differences were noted between the two groups including mode of delivery and neonatal or maternal adverse outcome. The interval from induction to vaginal delivery was significantly shorter in the misoprostol group (480±172 min vs. 657±436 min, P<0.01). Conclusions: Compared with prostaglandin E2, intracervical misoprostol is more effective in cervical ripening and labor induction at term. The higher frequency of uterine hypercontractility associated with the use of misoprostol did not increase the risk of adverse intrapartum and neonatal outcomes.
Effect of clomiphene citrate on endometrium thickness and echogenic patterns
Authors: Dehbashi S. , Parsanezhad M.E. , Alborzi S. , Zarei A.
Published: January 2003

Objective: To study the effect of clomiphene citrate (CC) on the thickness and echogenic pattern of the endometrium using vaginal sonography. Method: In this experimental prospective study, CC was given to 31 women with unexplained infertility. Thickness and echo patterns of the endometrium, as well as estradiol (E2) and progesterone (P) levels, were compared in women taking CC and in control patients during both the late proliferative and midsecretory phases of the menstrual cycle. Results: Endometrial thickness was significantly thinner in women taking CC (P<0.03) than in controls during the late proliferative phase but there was no significant difference during the midsecretory phase. The endometrial echogenic patterns of women taking CC who had conceived revealed endometrial thicknesses of grade III and grade IV on midsecretory days, but these findings were not significantly different from those of women who had not conceived (P=0.3). Serum E2 level was higher in women taking CC than in the controls on both late proliferative and midsecretory days (P<0.05). Conclusion: CC affects endometrium thickness on late proliferative days but not on midsecretory days, and does not alter the echogenic pattern of the endometrium.
Chute stationnaire d’un solide dans un fluide visqueux incompressible le long d’un plan incliné
Authors: Hillairet M , Serre D
Published: January 2003

The three-dimensional space is filled by a Newtonian fluid above a fixed ramp. A spherical solid body falls in the fluid under the action of the gravity. We are interested in permanent regimes, in which gravity and the action of the stress tensor of the fluid on the solid compensate. We prove that there exist such regimes, in which some parameters are given (including the gravity, the velocity of the solid and its distance to the ramp), but others, such the mass and the angular velocity, are determined by the motion.

We encounter two main difficulties. First in establishing a (non-explicit)
a priori
estimate. Last, because we are not able to convert the problem into the search of a zero of some outgoing vector field in a ball.

Un demi-espace, dont le bord est un plan incliné, est rempli d’un liquide Newtonien. Un solide spherique tombe dans le liquide, sous l’action de la gravité. Nous considérons ici le régime permanent, dans lequel la gravité et le tenseur des contraintes exercées par le fluide sur le solide se compensent. Le solide est donc en translation uniforme parallèle au bord, avec une rotation propre à vitesse constante.

Nous prouvons qu’il existe un tel régime, dans lequel certains parametres sont donnés (en particulier la gravité, la vitesse du solide et sa distance au bord) tandis que d’autres, tels que la masse du solide et sa vitesse angulaire, font partie des inconnues.

La difficulté essentielle est l’estimation a priori, qui n’est pas explicite. En particulier, nous ne sommes pas capables de ramener le problème, ou un problème approché, à la recherche d’un zéro d’un champ de vecteur sortant sur une boule.
On the convergence of numerical schemes for the Boltzmann equation
Authors: Vasseur A. , Horsin T. , Mischler S.
Published: January 2003

We consider a time and spatial explicit discretisation scheme for the Boltzmannequation. We prove some Maxwellian bounds on the resulting approximated solution anddeduce its convergence using a new time-discrete averaging lemma.

Nous considérons une discrétisation explicite en temps et espace de l’équation de Boltzmann. Nous exhibons des bornes au moyen de Maxwelliennes et en déduisons la convergence en utilisant un nouveau lemme de moyennisation discret en temps.
Sexual dimorphism in rat cerebrum and cerebellum: different patterns of catalytically active creatine kinase isoenzymes during postnatal development and aging
Authors: Ramı́rez Oscar , Jiménez Esperanza
Published: January 2003

During postnatal development, maturation and aging the Wistar rat cerebrum and cerebellum synthesize, in a different sex‐dependent manner, catalytically active dimeric cytosolic (c) muscle‐type (MM) and heart‐type (MB) creatine kinase (CK), besides the supposedly sole type brain‐specific (BB) CK. In both sexes, typical and atypical neuromuscular cCK isoenzymes were present during the study for 26 months. As in rat heart, females showed more cerebral cCK variants (41%) in comparison to males. Female rats exhibited about 93% more cerebellar variants of cCK isoenzymes as compared to males. The male cerebellum showed predominantly BB‐ and MB‐CK during the whole study in comparison to the female one that contained all neuromuscular cCK variants. Only female rats showed decreases and increases of cerebral CK specific activity. In contrast to males, coinciding with the weaning period, cerebral female CK activity decreased 45% from 14 to 21 days and increased about 3‐fold in female rats and only 1.3‐fold in males from 21 to 45 days of age. Contrary to the remarkable 4‐fold increase of chicken brain CK specific activity exhibited at old age, the rat did not show another cerebral CK activity increase during senescence in either sex. However, sex differences of CK specific activity appeared in the cerebellum at all ages. From the sex‐specific plateau phase at 45–60 days until 2.2 years of age, about a 41% independent increase of cerebellar CK specific activity was observed in both sexes. After puberty, the differential cerebellum–cerebrum values of CK specific activity were higher for female rats than males during youth, adulthood and senescence. The present work shows that in rat cerebrum and cerebellum, production of ATP through anaerobic transphosphorylation by the CK/PC system is sex‐and age‐specific, especially in the cerebellum, when glycolysis and the Krebs cycle lose capacity. As in rat heart, under physiological conditions at all ages the several cCK isoenzymes do participate in a gender‐specific manner, in favor of females, in diverse functions of the different cell compartments of glial and neuronal cells with regard to their high and fluctuating energy demands not completely covered by anaerobic and aerobic glycolysis.
A second source of precursor cells for the developing enteric nervous system and interstitial cells of Cajal
Authors: Sohal G.S. , Ali M.M. , Farooqui F.A.
Published: January 2003

The enteric nervous system is believed to be derived solely from the neural crest cells. This is partly based on the belief that the neural crest cells are the sole neural tube‐derived cells colonizing the gastrointestinal tract. However, recent studies have shown that after the emigration of neural crest cells an additional population of cells emigrates from the cranial neural tube. These cells originate in the ventral part of the hindbrain, emigrate through the site of attachment of the cranial nerves, and colonize a variety of developing structures including the gastrointestinal tract. This cell population has been named the ventrally emigrating neural tube (VENT) cells. We followed the fate of these cells in the gastrointestinal tract. Ventral hindbrain neural tube cells of chick embryos were tagged with replication‐deficient retroviral vectors containing the LacZ gene, after the emigration of neural crest from this region. In control embryos, the viral concentrate was dropped on the dorsal part of the neural tube. Embryos were sacrificed from embryonic days 3–12 and processed for the detection of LacZ positive ventrally emigrating neural tube cells. These cells colonized only the foregut, specifically the duodenum and stomach. Immunostaining with the neural crest cell marker HNK‐1 showed that they were HNK‐1 negative, indicating that they were not derived from neural crest. Cells were detected in three locations: (1) the myenteric and submucosal plexus of the enteric nervous system; (2) circular smooth muscle cell layer; and (3) mucosal lining of the lumen. A variety of specific markers were used to identify their fate. Some ventrally emigrating neural tube cells differentiated into neurons and glial cells, indicating that the enteric nervous system in the foregut develops from an additional source of precursor cells. It was also found that some of these cells differentiated into interstitial cells of Cajal, which mediate impulses between the enteric nervous system and smooth muscle cells, whereas others differentiated into epithelium. Altogether, these results indicate that the ventrally emigrating neural tube cells are multipotential. More importantly, they reveal a novel source of precursor cells for the neurons and glial cells of the enteric nervous system. The developmental and functional significance of the heterogeneous origin of the cell types remains to be established.
Axonal localization of delta Ca2+/calmodulin‐dependent protein kinase II in developing P19 neurons
Authors: Omar Faison M. , Perozzi Ed F. , Caran Nicole , Stewart Jennifer K. , Tombes Robert M.
Published: January 2003

Ca2+/calmodulin‐dependent protein kinase, type II (CaMK‐II) is an enzyme encoded by four genes (α, β, γ and δ) and traditionally associated with synaptic function in the adult central nervous system, but also believed to play a role during neuronal development. P19 mouse embryonic cells are a model system for neurogenesis and primarily express isozymes of δ CaMK‐II. It is not yet known whether or where δ CaMK‐II is expressed in P19 neurons. Using an antibody specific for the δ CaMK‐II C‐terminal tail, we detected a 20‐fold increase in levels of δ CaMK‐II along axons after 8 days of development. This coincides with increased mRNA and protein levels of δC CaMK‐II, which contains the alternative tail. This follows the initial stages of neurite outgrowth and β3 tubulin expression, which occur after 4 days. δ CaMK‐II co‐localizes with the axonal protein GAP‐43, but not the dendritic microtubule‐associated protein MAP‐2, a known substrate of α CaMK‐II. Like δ CaMK‐II, GAP‐43 shows increased expression after 8 days. These findings demonstrate developmental regulation of the alternative C‐terminal δ CaMK‐II exon and implicate endogenous δ CaMK‐II in axonal development in embryonic cells.
Suppression of motor evoked potentials in a hand muscle following prolonged painful stimulation
Authors: Svensson Peter , Miles Timothy S. , McKay Darrin , Ridding Michael C.
Published: January 2003

Earlier investigations have shown that stimulation of peripheral afferent nerves induces prolonged changes in the excitability of the human motor cortex. The present study compared the effect of experimental pain and non‐painful conditioning stimulation on motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) in the relaxed first dorsal interosseous (FDI) and flexor carpi ulnaris (FCU) muscles. The MEPs were measured in 10 healthy subjects, and stimulus—response curves were generated before and after each of four stimulation paradigms conducted in random order on separate occasions: (a) control; (b) “dual stimulation” consisting of electrical stimulation of the FDI motor point paired with TMS; (c) painful infusion of hypertonic saline in the FDI muscle; and (d) pain combined with dual stimulation. There were no significant changes in FDI MEPs following the control paradigm, and dual stimulation induced an increase in the FDI MEPs only inconsistently. In contrast, the painful stimulation and the combined pain and dual stimulation paradigms were followed by significant suppression of the FDI MEPs at higher stimulus intensities. No changes were observed in the FCU MEPs following the four paradigms. In two additional subjects, the responses evoked in FDI by direct stimulation of the descending corticospinal tracts were significantly depressed following painful stimulation of the FDI, although the ulnar‐evoked M‐waves remained constant. It is concluded that muscle pain is followed by a period with profound depression of MEPs amplitudes in the resting muscle, but that these changes are at least in part due to a lasting depression of the excitability of the motoneurones in the spinal cord. Hence, painful stimulation differs from non‐painful, repetitive stimulation, which facilitates the corticomotor pathway.
The treatment of complex regional pain syndrome (CRPS) involving upper extremity with continuous sensory analgesia
Authors: Margić Krunoslav , Pirc Jelka
Published: January 2003

Continuous sensory analgesia of brachial plexus (CSA BP) was only occasionally reported to have been used in the treatment of CRPS. In the past four years, we have treated 21 patients with a working diagnosis of CRPS. The treatment was instituted one to six months after inciting injury. All patients were admitted to hospital. In the first two days, the therapy consisted of elevation, cryotherapy, and active exercises. Five patients responded well to this initial physiotherapy (5/21). In 16 cases, no evident improvement was observed and CSA BP was introduced. At follow‐up (3–36 months), the results were: 13/16 (81%) had at least good results (excellent 2, good without any sequelae 5, good with sequelae of initial injury 6, and poor 3).

The results were judged as follows: excellent (completely normal hand); good (only temporary pain up to 2 on a 0–10 numeric rating scale; no signs of dysfunction of sympathetic nervous system; ROM of wrist over 50% of normal hand; ROM of fingers excellent or good; and the strength of hand grasp and key pinch over 50% of normal hand measured with dynamometer) and if any of the former criteria was missing, the result was defined as poor.
ELECTRONIC FETAL MONITORING
Authors: Banta H. David , Thacker Stephen B.
Published: January 2003

Objectives: The assessment of electronic fetal monitoring (EFM) carried out by the authors in the late 1970s provides an early case of a systematic review of evidence in health technology assessment. This paper identifies lessons pertinent for the present day in this field.

Methods: We reviewed our own files for the description of our assessment and reactions to it. We also reviewed recent literature to evaluate our observations in relation to recent evidence.

Results: Our findings of insufficient evidence of efficacy and concerns about safety have been confirmed by subsequent research. Still, despite findings and recommendations of prominent professional and governmental bodies, EFM continues in widespread use in the United States and Europe and is spreading into developing countries around the world. Aggressive attacks on our assessment as well as our skills and integrity have been mirrored in recent years by criticism of other researchers in health technology assessment.

Conclusions: The case of EFM points to the limitations of assessment without other actions to assure the implementation of results. Health technologies that are accepted by the majority of clinicians in a particular field may require extraordinary efforts to assure appropriate use of technology assessments.
IMPACT OF HEALTH TECHNOLOGY ASSESSMENTS
Authors: Britton Mona , Jonsson Egon
Published: January 2003

Objective: A recurring question is whether evidence from systematic reviews has any impact on medical practice. We have studied this question in relation to some conclusions in seven reports, where relatively simple means to monitor trends could be used.

Results: As recommended, in the report preoperative routines the number of preoperative examinations diminished at six hospitals, during around 3,000 operations studied, a savings of SEK 130 million. After the report on moderately elevated blood pressure sales of the preferred drugs, diuretics and beta-blockers, stopped falling while calcium blockers and ACE inhibitors stopped rising. As concluded in the report, general prostate cancer screening has not been introduced, but tests as a sign of opportunistic screening have increased. Bone density measurements were not recommended for screening, and sales of equipment have declined after the report. The use of neuroleptics as unspecific calming therapy for old persons was discouraged due to the serious side effects. The frequency of patients given this medication diminished from 34% to 28% at nursing homes after 1 year. For smoking cessation, the use of nicotine substitution medications has increased, which is in line with suggestions presented in the report. For stomach pain proton pump inhibitors given for functional dyspepsia have diminished in a region of the country after special efforts to disseminate the message.

Conclusions: It appears to be possible to monitor changes in practice corresponding to selected conclusions in systematic reviews. After rather extensive disseminating efforts, some results look encouraging.
4. CORPUS LINGUISTIC APPROACHES FOR DISCOURSE ANALYSIS
Authors: Conrad Susan
Published: January 2003

This chapter provides an overview of approaches within corpus linguistics that address discourse-level phenomena. The shared characteristics of all corpus-based research are first reviewed. Then four major approaches are covered: (1) investigating characteristics associated with the use of a language feature, for example, analyzing the factors that affect the omission or retention of that in complement clauses; (2) examining the realizations of a particular function of language, such as describing all the constructions used in English to express stance; (3) characterizing a variety of language, for example, conducting a multi-dimensional analysis to investigate relationships among the registers used in different settings at universities; and (4) mapping the occurrences of a feature through entire texts, for example, tracing how writers refer to themselves and their audience as they construct authority in memos. For each approach, a variety of studies are reviewed to illustrate the diverse perspectives that corpus linguistics can bring to our understanding of discourse. The chapter concludes with a brief overview of some other foci in corpus linguistics and suggests that two areas require particular attention for the advancement of discourse-oriented corpus studies: the need for more computer tools and computer programmers for corpus linguistics, and the need for further studies about how best to represent language varieties in a corpus.
5. BEYOND SCIENCE AND IDEOLOGY CRITIQUE: DEVELOPMENTS IN CRITICAL DISCOURSE ANALYSIS
Authors: Luke Allan
Published: January 2003

Critical discourse analysis (CDA) is an explicitly normative analysis of how texts and discourses work in ideological interests with powerful political consequences. This chapter provides an historical overview of CDA, placing it in the long lineage of attempts to develop a normative political linguistics beginning with Voloshinov. Recent approaches and procedures are discussed. These attempt to bring together text analysis with contemporary social, political, and cultural theory. The case is made that new conditions of economic and cultural globalization have created theoretical and empirical challenges for CDA and, more generally, for a critical applied linguistics. It is argued that these will require that CDA augment its strong focus on ideology critique with the study of texts that model the productive uses of power and discourse in new conditions.
8. DISCOURSE ISSUES IN CROSS-CULTURAL PRAGMATICS
Authors: Boxer Diana
Published: January 2003

This chapter focuses on recent research in cross-cultural pragmatics (CCP) as distinct from interlanguage pragmatics (IP). The essential difference between the two lies in the perspective from which each views cross-cultural communication. CCP takes the point of view that individuals from different societies or communities interact according to their own pragmatic norms, often resulting in a clash of expectations and, ultimately, misperceptions about the other group. The misperceptions are typically two-way; that is, each group misperceives the other. In an age in which cross-cultural interaction is the norm not only across societies but also within them, different rules of speaking have the potential to cause stereotypes, prejudice, and discrimination against entire groups of people. Research in the area of CCP can greatly aid in ameliorating these consequences. Recent studies that view CCP from this two-way perspective are the focus of this chapter. The overview of this body of research demonstrates the potential contribution of the field of applied linguistics to mutual understanding through the study of discourse issues in cross-cultural pragmatics.
11. TEACHERS' USES OF THE TARGET AND FIRST LANGUAGES IN SECOND AND FOREIGN LANGUAGE CLASSROOMS
Authors: Turnbull Miles , Arnett Katy
Published: January 2003

This chapter reviews recent theoretical and empirical literature regarding teachers' uses of the target (TL) and first (L1) languages in second (SL) and foreign (FL) language classrooms. Theoretically, the article explores several issues related to teachers' use of the L1 and the TL in the classroom: exposure to TL input, student motivation, cognitive considerations, code-switching, and appropriate teacher use of the L1. A review of recent discourse analysis studies examines how much, when, and why FL and SL teachers use the L1 and TL in their pedagogy. The article also presents findings from studies that have considered teachers' self-reports and teachers' and learners' beliefs and attitudes regarding the use of the L1 and the TL in FL and SL classrooms. The paper concludes with recommendations for future research.
13. DISCOURSE APPROACHES TO ORAL LANGUAGE ASSESSMENT
Authors: Young Richard F.
Published: January 2003

This chapter begins with a careful look at a sample conversation and examines the many layers of interpretation that different academic traditions have constructed in order to interpret it. These layers of interpretation include linguistic forms, nonverbal communication, linguistic context, situational context, and the embodied histories that participants bring to interaction. All are incorporated into a rich definition of discourse. The chapter then reviews recent studies that have compared the discourse of oral interaction in assessment with oral discourse in contexts outside assessment to show how different they are. The next section discusses studies that have related ways of speaking to the cultural values of communities of speakers with a view to understanding the cultural miscommunication that occurs in assessment of speaking in a second language community. The review concludes by stressing the wholeness of face-to-face interaction, listing the layers of interpretation of interaction that have not thus far been considered in oral testing, and setting out a potentially fertile area for future research.
The Interlocking Paradigm of Cultural Competence: A Best Practice Approach
Authors: Warren Barbara Jones
Published: January 2003

Cultural competence is a key factor in the delivery of quality psychiatric mental health (PMH) nursing care. The Interlocking Paradigm of Cultural Competence (IPCC) is a best-practice model developed from the work of Peplau, Leininger, Nichols, Campinha-Bacote, and Purnell. The IPCC has five interlocking factors (therapeutic, value, world view, process, and orientation) representing theoretical, philosophical, process, and assessment components. This article presents a discussion of the factors within the paradigm and the applicability and implications of the paradigm for PMH nurses’ use with their clients from diverse racial and ethnic cultural groups.
The emergence of potent forms of methamphetamine in Sydney, Australia: a case study of the IDRS as a strategic early warning system
Authors: TOPP LIBBY , DEGENHARDT LOUISA , KAYE SHARLENE , DARKE SHANE
Published: January 2003

A striking finding of the Illicit Drug Reporting System (IDRS) in recent years has concerned the emergence in Sydney of a number of different forms of potent methamphetamine. This paper demonstrates the operation of the IDRS in detecting and documenting an increase in both the availability and use of these forms of methamphetamine in Sydney, and Australia more widely, since 1998. Data from different components of the IDRS are utilized to propose that there are currently at least three forms of methamphetamine available in Sydney that are considered by the market to be distinct commodities: methamphetamine powder (‘speed’), base methamphetamine (‘base’) and crystalline methamphetamine (‘ice’/‘shabu’/‘crystal meth’). Base and ice are more potent forms of methamphetamine than speed, and international experience, along with preliminary data obtained from the IDRS, suggest that their use is associated with harms in a number of domains.
Perceived and self‐reported licit and illicit drug use among fishing industry workers on the mid‐north coast of Western Australia
Authors: CARRUTHERS SUSAN , BOOTS KEVIN , MIDFORD RICHARD
Published: January 2003

This paper describes the perceptions of boat owners and regional health workers about the use of alcohol and illicit substances within the West Australian mid‐west coast fishing industry. It also reports on a survey conducted among fishing industry workers concerning their consumption of alcohol and illicit drugs while at sea and in port. Boat owners and health workers perceived that cannabis and alcohol were the most commonly used substances, a perception borne out by the results of the survey. While the levels of illicit drug use for this group were lower than those reported in the fishing industry in an eastern Australian state (Queensland), they were nevertheless considerably higher than those recorded for the general population aged up to 35 years in a National Drug Survey. Cannabis was indeed the most frequently used illicit drug and injecting drug use was minimal. Alcohol use was particularly high and binge drinking described frequently. The results are compared with other industry findings and discussed in terms of occupational health and safety. Recommendations are suggested for future prevention programmes.
The effectiveness of cannabis crop eradication operations in New Zealand
Authors: WILKINS CHRIS , BHATTA KRISHNA , CASSWELL SALLY
Published: January 2003

At present the only information available on the effectiveness of the cannabis crop eradication programme in New Zealand is the total number of cannabis plants destroyed each year. These figures can only provide a very crude measure of the effectiveness of these operations. A better measure would be the percentage of total cannabis production destroyed—known as the drug seizure rate. This paper calculates the seizure rate of the cannabis crop eradication programme in New Zealand using the amount of cannabis reported consumed in the Alcohol and Public Health Research Unit's (APHRU) National Drug Survey. The seizure rate for the 1998 programme is calculated to be 26–31%. This compares favourably with drug seizure rates reported in other countries. The effectiveness of the cannabis crop eradication programme, and its apparent modest share of the total cannabis control budget, raises some intriguing questions about the role an expanded crop eradication programme could play in a future cannabis control strategy.
Programmes for the children of illicit drug‐using parents: issues and dilemmas
Authors: BANWELL CATHY , DENTON BARBARA , BAMMER GABRIELE
Published: January 2003

Concern about the health and general well‐being of children whose parents use illicit drugs has contributed to an increased interest in intervention programmes, but the number of such services is still limited. We review published papers about residential, home‐visiting and non‐residential programmes and use these and our experience in studying playgroup‐based clinics to outline issues and dilemmas they face. These include balancing trust and acceptance with intervention when problems are identified, harmonizing accessibility and flexibility with the provision of child‐focused activities and adult education, finding a location that is both suitable and affordable, appropriately supporting staff, collaborating with other services and securing adequate funding, including for ongoing evaluation and monitoring.