bluuebunny/crossref_metadata_2025 huggingface dataset:
Conjugation of arginine–glycine–aspartic acid peptides to thermoreversible N‐isopropylacrylamide polymers
Authors: Smith Erin , Bai Jiang , Oxenford Cassie , Yang Jennifer , Somayaji Ranjani , Uludag Hasan
Published: November 2003

Thermoreversible polymeric biomaterials are finding increased acceptance in tissue engineering applications. One drawback of the polymers is their synthetic nature, which does not allow direct interaction of mammalian cells with the polymers. This limitation may be alleviated by grafting arginine–glycine–aspartic acid (RGD) containing peptides onto the polymer backbone to facilitate interactions with cell‐surface integrins. Toward this goal, N‐isopropylacrylamide (NiPAM)‐based thermoreversible polymers containing amine‐reactive N‐acryloxysuccinimide (NASI) groups were synthesized. Conjugation of RGD‐containing peptides to polymers was demonstrated with 1H NMR spectroscopy and reverse‐phase high‐pressure liquid chromatography. The conjugation reaction was optimal at 4 °C and pH of 8.0, and increased with the increasing NASI content of polymers. With a peptide grafting ratio of 0.25 mol %, there was no significant change in the lower critical solution temperature of the polymers. Finally, the NASI‐containing polymers, cast as films, on tissue culture polystyrene, were shown to conjugate to RGD‐containing peptides and support C2C12 cell attachment. We conclude that NASI‐containing thermoreversible polymers are amenable for grafting biomimetic peptides to impart cell adhesiveness to the polymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3989–4000, 2003
Influence of nitroxide structure on the 2,5‐ and 2,6‐spirodicyclohexyl substituted cyclic nitroxide‐mediated free‐radical polymerization of styrene
Authors: Aldabbagh Fawaz , Dervan Paul , Phelan Marisa , Gilligan Karen , Cunningham Desmond , McArdle Patrick , Zetterlund Per B. , Yamada Bunichiro
Published: November 2003

The 2,6‐spirodicyclohexyl substituted nitroxide, cyclohexane‐1‐spiro‐2′‐(3′,5′‐dioxo‐4′‐benzylpiperazine‐1′‐oxyl)‐6′‐spiro‐1″‐cyclohexane (BODAZ), was investigated as a mediator for controlled/living free‐radical polymerization of styrene. The values of the number‐average molecular weight increased linearly with conversion, but the polydispersities were higher than for the corresponding 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy (TEMPO) and 2,5‐bis(spirocyclohexyl)‐3‐benzylimidazolidin‐4‐one‐1‐oxyl (NO88Bn) mediated systems at approximately 2.2 and 1.6 at 100 and 120 °C, respectively. These results were reflected in the rate coefficients obtained by electron spin resonance spectroscopy; at 120 °C, the values of the rate coefficients for polystyrene‐BODAZ alkoxyamine dissociation (kd), combination of BODAZ and propagating radicals (kc), and the equilibrium constant (K) were 1.60 × 10−5 s−1, 5.19 × 106 M−1 s−1, and 3.08 × 10−12 M, respectively. The value of kd was approximately one and two orders of magnitude lower, and that of K was approximately 20 and 7 times lower than for the NO88Bn and TEMPO adducts. These results are explained in terms of X‐ray crystal structures of BODAZ and NO88Bn; the six‐membered ring of BODAZ deviates significantly from planarity as compared to the planar five‐membered ring of NO88Bn and possesses a benzyl substituent oriented away from the nitroxyl group leading to a seemingly more exposed oxyl group, which resulted in a higher kc and a lower kd than NO88Bn. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3892–3900, 2003
Segmented poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene] via xanthate and dithiocarbamate precursors: A comparative study of thermal eliminations
Authors: Padmanaban G. , Nagesh K. , Ramakrishnan S.
Published: November 2003

Segmented poly[2‐methoxy‐5‐(2‐ethylhexloxy)‐1,4‐phenylene vinylene] (MEH‐PPV)‐x's, which contain conjugated segments of varying lengths that are interspersed by nonconjugated units along the polymer backbone, were synthesized by selective thermal elimination of precursors containing controlled amounts (x) of a thermally labile group, namely, xanthate or dithiocarbamate (DTC). These precursors were in turn synthesized by competitive nucleophilic substitution of the Wessling polyelectrolyte with varying molar fractions of the respective nucleophiles—potassium ethyl xanthate or sodium diethyl dithiocarbamate. Methanol, used as the reaction medium, also served to introduce the second thermally less labile nucleophilic substituent. This approach for the preparation of segmented MEH‐PPV‐x is superior to the previous approach that used acetate as the thermally labile group, because it offers greater control over the composition despite a simpler synthetic procedure. Detailed studies of the thermal‐elimination kinetics of the three precursors, namely, acetate, xanthate, and DTC, both in solution and in thin films, were carried by in situ monitoring of their ultraviolet–visible spectra. These studies revealed that the rates of elimination followed the order, DTC > xanthate > acetate. The activation energies for the elimination were, however, not widely different (ca. 30 kcal/mol), suggesting that the rates primarily reflected differences in the pre‐exponential factor. After elimination, the segmented MEH‐PPV‐x samples exhibited the expected redshift in their absorption and fluorescence spectra with an increasing molar fraction (x) of eliminated segments, which was accompanied by a drastic reduction in the fluorescence quantum yields. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3929–3940, 2003
Synthesis and properties of novel sulfonated polyimides containing 1,5‐naphthylene moieties
Authors: Miyatake Kenji , Asano Naoki , Watanabe Masahiro
Published: November 2003

A series of novel sulfonated polyimides (equivalent weight per sulfonic acid = 310–744 g/equiv) containing 10–70 mol % 1,5‐naphthylene moieties were synthesized as potential electrolyte materials for high‐temperature polymer electrolyte fuel cells. The polycondensation of 1,4,5,8‐naphthalene tetracarboxylic dianhydride, 4,4′‐diamino‐2,2′‐biphenyldisulfonic acid, and 1,5‐diaminonaphthalene gave the title polymer electrolytes. The polyimide electrolytes were high‐molecular‐weight (number‐average molecular weight = 36.0–350.7 × 103 and weight‐average molecular weight = 70.4–598.5 × 103) and formed flexible and tough films. The thermal properties (decomposition temperature > 260 °C, no glass‐transition temperature), stability to oxidation, and water absorption were analyzed and compared with those of perfluorosulfonic acid polymers. The polyimide containing 20 mol % 1,5‐naphthylene moieties showed higher proton conductivity (0.3 S cm−1) at 120 °C and 100% relative humidity than perfluorosulfonic acid polymers. The temperature and humidity dependence of the proton conductivity was examined. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3901–3907, 2003
Global burden of acute respiratory infections in children: Implications for interventions
Authors: Mulholland Kim
Published: November 2003

Despite dramatic advances in human health that have occurred during the 20th century, the end of the century still sees many places in the world with high child mortality rates. This is made worse by increasing inequity, such that there are still many communities in the world in which over 30% of children die before their fifth birthday. Estimates of the global burden of childhood pneumonia are based on the assumption that there is a predictable relationship between the childhood mortality rate and the proportion of that mortality that is attributable to pneumonia. As most child deaths occur at home and can only be investigated by verbal autopsy techniques, these estimates are very crude and provide only a guide to the overall burden of pneumonia. Recent estimates from the World Health Organization suggest that 1.9 million children die as a result of acute respiratory infection (ARI), mainly pneumonia, each year. For a number of reasons, this is likely to be an underestimate. Estimates of the morbidity burden attributable to pneumonia are also very approximate, as studies have used different and nonstandardized definitions of pneumonia. These estimates were originally used to assist with planning of ARI intervention activities and for advocacy to draw attention to the problem of ARI. Recently, the introduction of new vaccines against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (pneumococcus) raised the prospect of prevention of pneumonia by vaccination. For reasons outlined in this paper, great caution must be exercised before using existing pneumonia burden estimates to predict mortality savings that may accompany the introduction of these vaccines into developing countries. Pediatr Pulmonol. 2003; 36:469–474. © 2003 Wiley‐Liss, Inc.
Influence of data filtering on reliability of respiratory impedance and derived parameters in children
Authors: Schweitzer Cyril , Chone Claude , Marchal François
Published: November 2003

Forced oscillation impedance (Zrs) measurements are frequently corrupted by noisy data in children. Our aim was to improve the reliability of respiratory resistance (Rrs) and routine identification of its flow (V′) and volume (V) dependence during tidal breathing, according to ${\rm Rrs} = {\rm K}1 + {\rm K}2 \cdot \left| {{\rm V'}} \right| + {\rm K}3 \cdot {\rm V}$ Zrs was measured at 12 Hz, using a head generator in 23 children aged 4–13 years undergoing methacholine (Mch) challenge. Rrs, K1, K2, K3, and residual mean square error (RMSD), as well as reproducibility of the parameters, were obtained. Calculations were performed separately in inspiration and expiration on the raw data, and after eliminating values lying outside confidence intervals ranging from 99% (F3SD) to 95% (F2SD) of the mean Zrs. Filtering decreased RMSD and Rrs, F3SD improved reproducibility of Rrs in expiration compared to raw data. F2SD increased K1 and decreased the amplitude of K2 and K3 before and after Mch compared to F3SD. Rrs and K2 were significantly larger and K3 significantly more negative in expiration than in inspiration at all levels of filtering, probably because of the upper airways. F3SD appeared efficient in eliminating aberrant data, while allowing the identification of physiological variations of Rrs. Pediatr Pulmonol. 2003; 36:502–508. © 2003 Wiley‐Liss, Inc.
Symptoms of asthma: Comparison of a parent‐completed retrospective questionnaire with a prospective daily symptom diary
Authors: Hensley M.J. , Chalmers A. , Clover K. , Gibson P.G. , Toneguzzi R. , Lewis P.R.
Published: November 2003

In a study of the effects of indoor air pollution on the respiratory health of children in Newcastle, Australia, parental reports of symptoms experienced by children over the previous 12 months were compared with a prospective record of symptoms of cough and wheeze. Parents of 390 children aged 8–11 years completed a questionnaire about child and family respiratory health, which was used to assign children to one of four symptom groups: Wheeze (two or more attacks of wheezing in the last 12 months), Chest‐Colds (two or more chest‐colds in the last 12 months without wheezing), Cough Alone (a dry cough at night, without a cold or chest infection, that lasted for more than 2 weeks), or Control (none). A balanced sample of children (n = 139) was invited to participate further by completing lung function tests, atopy testing, and keeping a daily diary of peak expiratory flow (PEF) and symptoms of cough and wheeze over a 7‐week period. Valid data for the daily diary were provided by 66/85 (77.6%) of participants who commenced this stage (47.5% of the 139 invited to participate). The Wheeze group reported significantly more subsequent wheeze (median 16.8% of days) than the other three groups (median 0% of days). Parent reports of asthma‐like symptoms over the previous 12 months were consistent with the subsequent experience of symptoms recorded in a daily diary. Pediatr Pulmonol. 2003; 36:509–513. © 2003 Wiley‐Liss, Inc.
Immune response to hepatitis B vaccine in asthmatic children
Authors: Masten Barbara , McWilliams Bennie , Lipscomb Mary , Archibeque Teressa , Qualls Clifford , Kelly H. William , Schuyler Mark
Published: November 2003

Asthma is a disease that demonstrates chronic Th2 lymphocyte‐mediated pulmonary inflammation. We hypothesized that cytokines produced by asthmatic lung inflammation bias the immune response to antigens administered systemically toward a Th2 response, as assessed by serum IgE antibody and lymphocyte‐secreted IL‐4 and IL‐5. We also hypothesized that treatment of asthmatic children with local anti‐inflammatory agents reduces this cytokine‐mediated Th2 influence. We systemically immunized groups of asthmatic children (n = 29) who were participating in a long‐term, randomized, placebo‐controlled clinical trial of inhaled anti‐inflammatory therapy (Childhood Asthma Management Program) and nonasthmatic children (n = 12) with hepatitis B (Hep B) antigen, and examined their antigen‐specific antibody and lymphocyte cytokine secretion profiles. The asthmatic population demonstrated an increased amount of Th2‐mediated serum IgE anti‐Hep B antibody, as compared to nonasthmatic children; but comparable amounts of IgG1, IgG2, IgG3, IgA, and IgM anti‐Hep B antibody and lymphocyte IFNγ, IL4, and IL5. There was no significant difference of antibody isotype or cytokine production between asthmatic subjects receiving treatment with budesonide or nedocromil, as compared to placebo. In conclusion, there is a subtle bias in responses to systemic immunization in children with asthma, but anti‐inflammatory therapy does not affect this bias. The findings support the concept that the Th2 bias may be largely genetic. Importantly, we confirmed that children with asthma, including even those on inhaled corticosteroids, responded to Hep B immunization as well as did nonasthmatic children with the major isotypes of anti‐Hep B antibody, suggesting that vaccine protection against hepatitis B is not influenced by inhaled steroid therapy. Pediatr Pulmonol. 2003; 36:522–528. © 2003 Wiley‐Liss, Inc.
Production of TNF‐α by polymorphonuclear leukocytes during mechanical ventilation in the surfactant‐depleted rabbit lung
Authors: Noda Eri , Hoshina Hiroaki , Watanabe Hiroshi , Kawano Toshio
Published: November 2003

Previous studies showed that the production of tumor necrosis factor‐α (TNF‐α) and the number of recovered cells were much higher in the conventional mechanical ventilation (CMV) group than in the high‐frequency oscillation (HFO) group at the end of mechanical ventilation in this model. But the type of cells that generated TNF‐α in the lungs remained unclear. It was shown that the alveolar macrophage was the source of TNF‐α in the early stage, but that in the later stage, the cells in the lung lavage fluid contained almost no macrophages. Thus we hypothesized that in the surfactant‐depleted lung model, one of the sources of TNF‐α after 4 hr of CMV is polymorphonuclear leukocyte (PMN), a type of cell which was numerous at that time. We performed the experiment in the same lung lavage model. The results were as follows. All Pa02 values for the HFO group were significantly greater than the corresponding values for the CMV group throughout the experiment (P < 0.05). More than 96% of the recovered cells of the lung lavage fluid at the end of ventilation were PMN. Cell counts after ventilation of HFO and CMV groups were 183.0 ± 40.8 (mean ± SD, n = 6)/μl and 1,106.0 ± 310.0/μl, respectively (P < 0.05). Levels of rabbit TNF‐α in the lavage fluid before and after 4 hr ventilation were 43.3 ± 103.7 pg/ml and 2,406.0 ± 1,525.1 pg/ml, respectively, in the CMV group. In the HFO group, these levels were 26.6 ± 52.0 pg/ml and 613.3 ± 362.2 pg/ml, respectively. The level of TNF‐α was significantly greater in the CMV group after ventilation (P < 0.05). We performed RT‐PCR analysis, in which we showed the presence of TNF‐α mRNA in the intraalveolar cells (PMN) after 4 hr of CMV, and then demonstrated a positive immunofluorescence reaction to anti‐TNF‐α antibody in PMN separated from the lavage fluid. Our conclusion is that in this surfactant‐depleted lung model, PMN is one of the sources of TNF‐α in the lavage fluid after 4 hr of CMV. Pediatr Pulmonol. 2003; 36:475–481. © 2003 Wiley‐Liss, Inc.
Phosphodiesterase inhibitors for persistent pulmonary hypertension of the newborn: A review
Authors: Travadi J.N. , Patole S.K.
Published: November 2003

Persistent pulmonary hypertension of the newborn (PPHN) is a complex syndrome with multiple causes, with an incidence of 0.43–6.8/1,000 live births and a mortality of 10–20%. Survivors have high morbidity in the forms of neurodevelopmental and audiological impairment, cognitive delays, hearing loss, and a high rate of rehospitalization. The optimal approach to the management of PPHN remains controversial. Inhaled nitric oxide (iNO) is currently regarded as the gold standard therapy, but with as many as 30% of cases failing to respond, has not proven to be the single magic bullet. Given the complex pathophysiology of the disease, any such magic bullet is unlikely. A number of recent studies have suggested a role for specific phosphodiesterase (PDE) inhibitors in the management of PPHN. Sildenafil, a specific PDE5 inhibitor, appears the most promising of such agents. We aim to review the current status and limitations of iNO and the potential of PDE inhibitors in the management of PPHN. The reasons why caution is warranted before specific PDE5 inhibitors like sildenafil are labelled as potential magic bullets for PPHN will be discussed. The need for randomized‐controlled trials to determine the safety, efficacy, and long‐term outcome following treatment with sildenafil in PPHN is emphasized. Pediatr Pulmonol. 2003; 36:529–535. © 2003 Wiley‐Liss, Inc.
The ability of indigenous micro‐organisms to degrade isoproturon, atrazine and mecoprop within aerobic UK aquifer systems
Authors: Johnson Andrew C , White Craig , Lal Bhardwaj C , Dixon Andy
Published: November 2003

The potential for the herbicides isoproturon, atrazine and mecoprop to degrade in the major UK aquifers of chalk, sandstone and limestone was studied using laboratory microcosms spiked at 100 µg litre−1. Significant mecoprop degradation was only observed in sandstone groundwater samples. Atrazine transformation, based on the formation of metabolites, did occur in most groundwater samples, but only at a rate of 1–3% per year. A potential to degrade isoproturon was observed in groundwater samples from each of the aquifer types, with the most rapid and consistent degradation occurring at the sandstone field site. Biodegradation was confirmed by the formation of monodesmethyl‐ and didesmethyl‐isoproturon. Isoproturon degradation potential rates obtained from the groundwater microcosms could not be correlated with either dissolved organic carbon or numbers of bacteria in the groundwater. It was noted that the ability of the groundwater at a field site to degrade a pesticide was not related to performance of the soil above. Crown copyright 2003. Reproduced with the permission of Her Majesty's Stationery Office. Published for SCI by John Wiley & Sons, Ltd.
Effect of plate separation on restrained burst test
Authors: Feliú‐Báez, Rosamari , Lockhart Hugh E.
Published: November 2003

The deformation experienced by a package during an unrestrained burst test is not the same in every case. This deformation will direct the forces resulting from the internal pressure to specific areas depending on the package geometry, the material and the type of seal. It may influence the resulting burst values and the interpretation of the results in general. In recent years, the use of restraining fixtures in the burst test has been suggested by both industry and academic researchers. It is thought that restraining plates can limit the extent and variation of deformation of the package during the burst test.
Restrained burst tests, using different plate separations, were performed for pouches and trays. It was found that for both types of packages; the burst pressure is inversely proportional to plate separation. Copyright © 2003 John Wiley & Sons, Ltd.
On large intersecting subfamilies of uniform setfamilies
Authors: Duke Richard A. , Erdős Paul , Rödl Vojtěch
Published: November 2003

In an earlier work R. A. Duke and V. Rödl, The Erdős–Ko–Rado theorem for small families, J Combin Theory Ser A 65(2) (1994), 246–251 it was shown that for t a fixed positive integer and κ a real constant, 0 < κ < 1/2, if n is sufficiently large each family 𝒜 of ⌊κn⌋‐element subsets of [n] of size N (linear in n) contains a t‐intersecting subfamily of size at least (1 − o(1))κN. Here we consider the case when t, the intersection size, is no longer bounded, specifically t = ⌊τn⌋ for 0 < τ < κ. We show that for sufficiently large n and N each family of this type contains an r‐wise t‐intersecting subfamily of size at least N1−δ, and that, apart for the size of δ, this result is the best possible. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2003
One line and n points
Authors: Gärtner Bernd , Tschirschnitz Falk , Welzl Emo , Solymosi József , Valtr Pavel
Published: November 2003

We analyze a randomized pivoting process involving one line and n points in the plane. The process models the behavior of the RANDOM‐EDGE simplex algorithm on simple polytopes with n facets in dimension n − 2. We obtain a tight O(log2 n) bound for the expected number of pivot steps. This is the first nontrivial bound for RANDOM‐EDGE, which goes beyond bounds for specific polytopes. The process itself can be interpreted as a simple algorithm for certain 2‐variable linear programming problems, and we prove a tight Θ(n) bound for its expected runtime. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2003
On restricted min‐wise independence of permutations
Authors: Matoušek Jiří , Stojaković Miloš
Published: November 2003

A family of permutations ℱ ⊆ Sn with a probability distribution on it is called k‐restricted min‐wise independent if we have Pr[min π(X) = π(x)] = 1/|X| for every subset X ⊆ [n] with |X| ≤ k, every x ∈ X, and π ∈ ℱ chosen at random. We present a simple proof of a result of Norin: every such family has size at least

Some features of our method might be of independent interest. The best available upper bound for the size of such family is 1 + ∑ (j − 1)(). We show that this bound is tight if the goal is to imitate not the uniform distribution on Sn, but a distribution given by assigning suitable priorities to the elements of [n] (the stationary distribution of the Tsetlin library, or self‐organizing lists). This is analogous to a result of Karloff and Mansour for k‐wise independent random variables. We also investigate the cases where the min‐wise independence condition is required only for sets X of size exactly k (where we have only an Ω(log log n + k) lower bound), or for sets of size k and k − 1 (where we already obtain a lower bound of n − k + 2). © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2003
Random suffix search trees
Authors: Devroye Luc , Neininger Ralph
Published: November 2003

A random suffix search tree is a binary search tree constructed for the suffixes Xi = 0 · BiBi+1Bi+2… of a sequence B1, B2, B3, … of independent identically distributed random b‐ary digits Bj. Let Dn denote the depth of the node for Xn in this tree when B1 is uniform on ℤb. We show that for any value of b > 1, 𝔼Dn = 2 log n + O(log2log n), just as for the random binary search tree. We also show that Dn/𝔼Dn → 1 in probability. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2003
5‐HT6 receptor antagonist SB‐271046 enhances extracellular levels of monoamines in the rat medial prefrontal cortex
Authors: Lacroix Laurent P. , Dawson Lee A. , Hagan Jim J. , Heidbreder Christian A.
Published: November 2003

The present study investigated the neurochemical effects of the selective 5‐HT6 receptor antagonist SB‐271046 in the rat medial prefrontal cortex (mPFC). The effect of SB‐271046 on extracellular levels of dopamine (DA), norepinephrine (NE), and serotonin (5‐HT) in the mPFC was examined using in vivo microdialysis in the freely moving rat. SB‐271046 (10 mg/kg, p.o.) produced a significant increase in extracellular levels of both DA and NE without altering 5‐HT neurotransmission. These results further support the rationale for the use of 5‐HT6 receptor antagonists in the treatment of cognitive dysfunction associated with psychiatric diseases. Synapse 51:158–164, 2004. © 2003 Wiley‐Liss, Inc.
Bilateral subthalamic nucleus lesion reverses L‐dopa‐induced motor fluctuations and facilitates dyskinetic movements in hemiparkinsonian rats
Authors: Marin Concepció , Jiménez Anna , Tolosa Eduardo , Bonastre Mercè , Bové Jordi
Published: November 2003

Glutamatergic overactivity might be involved in L‐dopa‐induced motor complications since glutamate antagonists reverse and prevent L‐dopa‐induced shortening in motor response duration in 6‐hydroxydopamine‐lesioned (6‐OHDA) rats and improve L‐dopa‐induced dyskinesias in parkinsonian monkeys and in patients with Parkinson's disease (PD). An increase in the subthalamic nucleus (STN) glutamatergic activity is believed to contribute to the pathophysiology of PD. However, the role of STN activity in L‐dopa‐induced motor complications is not so clear. In this study, the effect of STN lesions on L‐dopa‐induced motor response complications was investigated in rats with a nigrostriatal pathway lesion induced by 6‐OHDA. Animals were injected with 6‐OHDA in the medial forebrain bundle and treated with L‐dopa or saline for 22 days. On day 16, animals were randomly distributed in groups that underwent surgery in the STN ipsilateral or contralateral to 6‐OHDA lesion, or bilateral. Rotational behavior was measured on days 1, 15, and 22. Attenuation of STN activity by contralateral and bilateral, but not ipsilateral, STN lesion reversed the shortening in motor response duration induced by L‐dopa. L‐dopa administration, but not saline, induced prominent dyskinesias in 6‐OHDA‐lesioned rats with additional bilateral STN lesions. The results indicate that bilateral lesions of STN potentiate the duration of L‐dopa‐induced motor response and facilitate chronic L‐dopa‐induced abnormal involuntary movements in 6‐OHDA‐lesioned rats. The characteristics of the abnormal involuntary movements observed in these animals are similar to L‐dopa‐induced dyskinesias in parkinsonian patients and might be useful as an experimental model for the study of L‐dopa‐induced dyskinesia. Synapse 51:140–150, 2004. © 2003 Wiley‐Liss, Inc.
PET quantification of muscarinic cholinergic receptors with [N‐11C‐methyl]‐benztropine and application to studies of propofol‐induced unconsciousness in healthy human volunteers
Authors: Xie Guoming , Gunn Roger N. , Dagher Alain , Daloze Thierry , Plourde Gilles , Backman Steven B. , Diksic Mirko , Fiset Pierre
Published: November 2003

This work evaluated kinetic analysis methods for estimation of the receptor availability of the muscarinic receptor using dynamic positron emission tomography (PET) studies with [N‐11C‐methyl]‐benztropine. The study also investigated the effect of propofol on central muscarinic receptor availability during general anesthesia. Six volunteers were scanned three times, once for baseline while awake, once during unconsciousness, and once after recovery to conscious level. An irreversible two‐tissue compartment model was used to estimate the [N‐11C‐methyl]‐benztropine specific binding rate constant k3, a measure of muscarinic receptor availability. Two different estimation methods were used: 1) optimization with positivity constraints on all the parameters; 2) optimization with additional constraints determined from a one‐tissue compartment fit to the cerebellum. In regions with low to middle muscarinic receptor density, the k3 values from method (2) had lower standard errors than that for method (1) and gave a higher correlation with the density of muscarinic receptors measured in human tissue by in vitro studies (r2 of 0.98 for Method 2 and r2 of 0.72 for Method 1). But the k3 values determined by Method 2 had higher errors for regions with high muscarinic receptor density compared to Method 1. For both methods the mean k3 values during unconsciousness were generally lower than those during awake for most regions evaluated. Therefore, the method with additional constraints derived from the cerebellum (Method 2) was deemed superior for regions with low to middle muscarinic receptor density, while the method with positivity constraint is the better choice in the regions with high muscarinic receptor density. Our results also suggest the existence of propofol‐related reductions in muscarinic receptor availability. Synapse 51:91–101, 2004. © 2003 Wiley‐Liss, Inc.
Uptake of 6‐[18F]fluoro‐L‐dopa and [18F]CFT reflect nigral neuronal loss in a rat model of Parkinson's disease
Authors: Forsback Sarita , Niemi Riitta , Marjamäki Päivi , Eskola Olli , Bergman Jörgen , Grönroos Tove , Haaparanta Merja , Haapalinna Antti , Rinne Juha , Solin Olof
Published: November 2003

In order to characterize the sensitivity of an analog of levodopa and a dopamine transporter ligand to detect defects in nigrostriatal function, the uptake of [18F]FDOPA and [18F]CFT was studied ex vivo in a rat model of Parkinson's disease. The brains of these rats were unilaterally lesioned with an intranigral injection of 6‐hydroxydopamine. The lesioned animals were divided into three groups subject to their behavior after pharmacological challenges. Circling behavior was recorded after amphetamine, apomorphine, and L‐DOPA challenge in order to predict lesion size. The spatial distribution of radioactivity after [18F]FDOPA or [18F]CFT injection in brain sections was determined with digital autoradiography. Regions of interest were left/right striatum, left/right substantia nigra, and cerebellum. The degree of unilateral lesion for each animal was confirmed by counting of nigral tyrosine hydroxylase‐positive cell bodies. With both tracers the uptake in the lesioned side was lower than in the intact side in the striatum and in the substantia nigra. In conclusion, both tracers clearly demonstrated nigrostriatal dopaminergic hypofunction and correlated with the number of nigral dopaminergic neurons. However, [18F]FDOPA showed a much higher unspecific uptake of radioactivity, due to extensive metabolism; therefore, this tracer was less sensitive than the transporter tracer [18F]CFT to detect these defects. Synapse 51:119–127, 2004. © 2003 Wiley‐Liss, Inc.
Is Doppler prediction of anemia effective in the growth‐restricted fetus?
Authors: Makh D. S. , Harman C. R. , Baschat A. A.
Published: November 2003

Objective

To evaluate the utility of middle cerebral artery (MCA) and umbilical artery (UA) Doppler to predict anemia in intrauterine growth restricted (IUGR) fetuses.

Methods

Fetuses with an abdominal circumference < 5th percentile had UA and MCA Doppler prior to delivery. The UA pulsatility index (PI), MCA PI, ratio between the MCA/UA PI (cerebroplacental ratio, CPR) and MCA peak systolic velocity (PSV) were measured. A complete blood count was determined from a peripheral venous sample drawn at delivery. Anemia was defined as a hemoglobin value of < 13 g/dL. MCA PSV Z‐scores (standard deviation from gestational age mean using references ranges by Mari et al. and Kurmanavicius et al.) were related to hemoglobin using linear regression analysis. In addition, UA absent end‐diastolic velocity (AEDV), brain sparing (MCA PI > 2 SDs below gestational age mean), low CPR (> 2 SDs below gestational age mean) and an elevated MCA PSV (> 2 SDs) were evaluated for their predictive accuracy for anemia.

Results

Of 97 IUGR neonates 23 were anemic (23.7%). The MCA PSV was significantly related to hemoglobin using either reference range (Mari et al., F = 22.1577, Kurmanavicius et al., F = 21.8188, P < 0.001, respectively). However, using categorical cut‐offs as well as regression analysis none of the Doppler parameters could be identified to provide clinically useful prediction of anemia.

Conclusion

Parameters of MCA and UA vascular impedance and MCA PSV are significantly related to anemia in IUGR neonates. Despite this relationship the predictive accuracy is unacceptable for the clinical application in the setting of IUGR. Altered cardiovascular dynamics in IUGR fetuses may be responsible for this effect. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Prospective evaluation of renal artery resistance and pulsatility indices in normal pregnant women
Authors: Dib F. R. , Duarte G. , Sala M. M. , Ferriani R. A. , Berezowski A. T.
Published: November 2003

Objectives

To establish normal values for renal artery resistance index (RI) and pulsatility index (PI) during gestation and, by comparison with non‐pregnant controls, to determine if pregnancy affects these indices.

Methods

This was a prospective longitudinal study involving 36 normal pregnant women who underwent a total of 280 examinations at 4‐week intervals from the 6th gestational week to the end of pregnancy. High‐resolution ultrasound equipment with ‘triplex’ Doppler facilities was used. RI and PI were obtained for the main arteries of both kidneys. The same evaluation was performed in 15 non‐pregnant women as controls.

Results

The mean RI in pregnant and non‐pregnant women was the same (0.65 ± 0.03 for controls and 0.65 ± 0.02 for the pregnant women). For PI, the values were 1.25 ± 0.12 for non‐pregnant women and 1.18 ± 0.09 for pregnant women. The only statistical difference (P < 0.05) was found between the PI of the left renal artery in the control group (1.29 ± 0.20) and that in the pregnant group at the 8–12‐week interval of gestational age (1.08 ± 0.14).

Conclusions

No significant alterations in renal artery RI and PI occur during normal pregnancy, except for in a subgroup of patients between 8 and 12 weeks of gestation. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Diminutive fetal left ventricle at mid‐gestation associated with persistent left superior vena cava and coronary sinus dilatation
Authors: Jouannic J.‐M. , Picone O. , Martinovic J. , Fermont L. , Dumez Y. , Bonnet D.
Published: November 2003

In a fetus with a small left ventricle diagnosed at mid‐gestation, a persistent left superior vena cava connected to a dilated coronary sinus was detected. Although the size of the mitral annulus appeared to be normal, opening of the mitral valves was restricted in diastole. Echocardiographic follow‐up showed no significant growth of the left ventricle and termination of pregnancy was carried out at 31 weeks at the parents' request. In addition to the prenatal findings, postmortem examination revealed a small mitral annulus with abnormal insertion of the mitral valve chordae tendineae. We hypothesized that abnormal venous return to a dilated coronary sinus may have led to mitral valve dysfunction and hypoplasia. On the other hand the left ventricular hypoplasia we observed may have involved a global abnormality of the left‐sided cardiac structures. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Patient acceptance of transvaginal sonography in the early pregnancy unit setting
Authors: Dutta R. L. , Economides D. L.
Published: November 2003

Objective

To establish the acceptability of transvaginal scanning in patients attending an early pregnancy unit (EPU) due to problems in early pregnancy such as vaginal bleeding.

Methods

An unselected group of pregnant women who were less than 8 weeks' gestation were invited to complete a questionnaire before the transvaginal scan regarding their views about the pregnancy and about the scan itself. They were asked to complete a second questionnaire after the scan had been performed. Information was collected about the presenting symptoms and the final diagnosis.

Results

Of a total of 107 patients, the most common reason for attending the EPU was vaginal bleeding (51.4%). The primary concern for the majority of these women was their pregnancy, rather than the scan procedure itself. Their concerns about the scan were not altered by a previous history of miscarriages or by maternal age. After the scan, more than 77% of patients scored ≤ 3 out of 10 with regard to discomfort, pain and embarrassment. Only 1.9% experienced marked discomfort, scoring > 8 out of 10. The scores were not altered by the patients' diagnoses. A total of 99% of patients said that they would agree to have a similar procedure in the future.

Conclusion

This questionnaire‐based study confirms that patients attending with problems in early pregnancy find transvaginal sonography acceptable. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Transvaginal ultrasound in pregnancy: its acceptability to women and maternal psychological morbidity
Authors: Clement S. , Candy B. , Heath V. , To M. , Nicolaides K. H.
Published: November 2003

Objectives

To assess the acceptability to women of antenatal transvaginal ultrasound scans; to compare the characteristics of women who accept the offer of a transvaginal scan with those who decline; to establish the prevalence of any psychological morbidity associated with the scan.

Methods

The study was a cross‐sectional questionnaire survey. Women were recruited from two hospitals in South London. The sample consisted of 755 pregnant women who had a transvaginal scan at 23 weeks' gestation to assess the risk of preterm delivery and 167 women who were offered the transvaginal scan but declined. Women completed a questionnaire at home. Those who reported finding the scan a difficult experience were sent a questionnaire 4 weeks post‐scan to assess its longer term impact. The main outcomes were acceptability (assessed by individual questionnaire items); anxiety before and during the scan (Spielberger State‐trait Anxiety Inventory); pain during the scan (Present Pain Intensity Scale of the McGill Pain Questionnaire); psychological trauma (Impact of Event Scale).

Results

Over half (55.2%) of women accepted the offer of a transvaginal scan, according to hospital records. The majority of study participants who had transvaginal ultrasound reported finding the experience acceptable. Women experienced some anxiety before and during the scan and over a third experienced some (usually mild) pain during the procedure. Twelve women (1.6%) reported clinically significant levels of psychological trauma in relation to the scan.

Conclusions

Antenatal transvaginal ultrasound for assessing the risk of preterm delivery is an acceptable procedure for the majority of women. A significant minority decline the scan. The procedure has some psychological sequelae for some women. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal sonographic diagnosis of aortic arch anomalies
Authors: Yoo S.‐J. , Min J.‐Y. , Lee Y.‐H. , Roman K. , Jaeggi E. , Smallhorn J.
Published: November 2003

Aortic arch anomalies refer to congenital abnormalities of the position or branching pattern, or both of the aortic arch. Although aortic arch anomalies are not uncommon, reports on their prenatal diagnosis are scarce. Insight into the hypothetical arch model is crucial to understanding anomalies of the aortic arch in the fetus. Recognition of the trachea, three major vessels, ductus arteriosus and descending aorta in the axial views of the upper mediastinum is necessary for a complete fetal cardiac assessment. Clues to aortic arch anomalies include abnormal position of the descending aorta, absence of the normal ‘V’‐shaped confluence of the ductal and aortic arches, a gap between the ascending aorta and main pulmonary artery in the three‐vessel view, and an abnormal vessel behind the trachea with or without a vascular loop or ring around the trachea. Meticulous attention to anatomic landmarks will lead to successful prenatal diagnosis of important vascular rings making early postnatal management possible. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Jugular vein and carotid artery blood flow in fetuses with increased nuchal translucency at 10–14 weeks' gestation
Authors: Martínez J. M. , Echevarría M. , Gómez O. , Del Río M. , Borrell A. , Puerto B. , Fortuny A.
Published: November 2003

Objective

The aim of our study was to obtain measurements of the jugular vein and carotid artery pulsatility index (PI) at 10–14 weeks' gestation in chromosomally normal and abnormal fetuses with or without increased nuchal translucency (NT), in order to explore whether a relationship exists between increased NT and overperfusion of the head.

Methods

This was a prospective study involving 179 pregnant women at high risk for chromosomal anomalies or structural malformations who were referred for chorionic villus sampling or first‐trimester ultrasound examination at 10–14 weeks' gestation, respectively. Color and pulsed Doppler ultrasound were used to obtain jugular vein and carotid artery blood flow velocity waveforms at the level of the mid‐neck. All Doppler measurements were obtained by a single investigator. The PIs of the jugular vein and carotid artery were correlated with NT measurement and fetal karyotype.

Results

Doppler measurements of the jugular vein and carotid artery were successfully obtained in 90.5% of the fetuses. The fetal karyotype was abnormal in 13 cases, including three trisomies 21 and two trisomies 18, and normal in 149 cases. In the group with normal karyotype the NT was above the 95th percentile in 22 cases (15%). No correlation between the jugular vein or the carotid artery PI and the thickness of the NT was found. There were no significant differences when comparing the values of the jugular vein and carotid artery PI between the group with normal NT and the group with increased NT, or between the group with a normal karyotype and an abnormal karyotype.

Conclusion

Our results suggest that NT is not related to blood flow impedance in either the carotid artery or the jugular vein. Overperfusion and venous congestion of the head do not appear to be a causative pathophysiological mechanism involved in increased NT. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Ear length in trisomy 21 fetuses at 11–14 weeks of gestation
Authors: Sacchini C. , El‐Sheikhah A. , Cicero S. , Rembouskos G. , Nicolaides K. H.
Published: November 2003

Objective

To determine the value of measuring fetal ear length at 11–14 weeks of gestation in screening for chromosomal defects.

Methods

The fetal ear length was measured in 450 fetuses immediately before chorionic villus sampling for karyotyping at 11–14 weeks of gestation.

Results

The median gestational age was 12 (range, 11–14) weeks. The fetal ear was successfully examined in all cases. The fetal karyotype was normal in 409 cases and abnormal in 41, including 32 cases of trisomy 21. In the chromosomally normal group the fetal ear length increased significantly with crown–rump length from a mean of 3.7 mm at 45 mm to 6.9 mm at 84 mm. In the trisomy 21 fetuses the median ear length was significantly below the normal mean for crown–rump length by 0.45 mm (P = 0.013) but it was below the 5th centile of the normal range in only two (6.3%) of the cases. There was no significant association between the delta score of ear length and delta nuchal translucency in either the chromosomally normal (r = − 0.015, P = 0.753) or the trisomy 21 fetuses (r = − 0.014, P = 0.94).

Conclusions

At 11–14 weeks of gestation the ear length in trisomy 21 fetuses is significantly reduced but the degree of deviation from normal is too small for this measurement to be useful in screening for trisomy 21. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Selective feticide in monochorionic twin pregnancies by ultrasound‐guided umbilical cord occlusion
Authors: Gallot D. , Laurichesse H. , Lemery D.
Published: November 2003

Objectives

To evaluate the feasibility and the follow‐up of three different ultrasound‐guided procedures of selective feticide in monochorionic twin pregnancies.

Methods

This was a retrospective observational study of patients who underwent percutaneous umbilical cord occlusion between July 1993 and January 2002 after diagnosis of previable, abnormal, monochorionic twin pregnancy, with imminent cardiac failure of one of the fetuses. Selective feticide was performed under general anesthesia using three different ultrasound‐guided techniques: cord ligation using a suture (four cases), cord coagulation using bipolar forceps (five cases) and cord compression by squeezing the cord against the uterine wall (two cases).

Results

During the study period, 11 patients underwent selective feticide before 28 weeks' gestation in our department (eight recipient twins with twin–twin transfusion syndrome (TTTS), one of which also had a congenital diaphragmatic hernia, and three acardiac twins). One procedure failed due to maternal hemorrhage following insertion of the trocar (both fetuses died after emergency Cesarean section). One cotwin died a few minutes after the procedure and one survivor died within the neonatal period. The mean gestational age at the time of the procedure was 24 weeks of gestation and the mean gestational age at delivery was 31.1 weeks. Premature rupture of membranes occurred in four cases. Eight babies were alive and well at the time of writing.

Conclusions

Ultrasound guidance can enable selective feticide to be performed via a single port. Although bipolar coagulation seemed to be the easiest technique, the choice of procedure depends on local conditions. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Protein A‐tagging for purification of native macromolecular complexes from Candida albicans
Authors: Blackwell Chris , Russell Claire L. , Argimon Silvia , Brown Alistair J. P. , Brown Jeremy D.
Published: November 2003

Protein A‐tagging has become an important tool in characterization of protein–protein interactions in many systems, allowing purification of multicomponent complexes under native conditions. Here we provide a set of vectors that allow protein A‐tagging in Candida albicans, through addition of the tag to open reading frames. These vectors were successfully used to generate stably tagged proteins that were functional, shown to be localized appropriately or assembled into complexes. These new vectors comprise a useful addition to the C. albicans molecular toolbox. Copyright © 2003 John Wiley & Sons, Ltd.
An improved tetO promoter replacement system for regulating the expression of yeast genes
Authors: Yen Kuangyu , Gitsham Paul , Wishart Jill , Oliver Stephen G. , Zhang Nianshu
Published: November 2003

Regulatable promoters are commonly used to control the expression of, especially, essential genes in a conditional manner. Integration of such promoters upstream of an ORF using one‐step PCR‐mediated homologous recombination should be particularly efficient. However, integration of the original KanMX4‐tetO promoter cassette (Belli et al., 1998a) into the relatively short upstream regions of many yeast genes is often problematic, presumably due to the size (3.9 kb) of the replacement cassette. We have created a new, shorter, KanMX4‐tetO cassette by removing the transactivator (tTA) sequence from the original cassette. The transactivator (tTA) has been integrated into the yeast genome to create a new strain for use with the new system, which has a greatly increased efficiency of promoter substitution. With it, we have been able to create strains that could not be made with the original cassette. To increase the throughput of promoter substitutions, we have developed a new assay for testing doxycycline sensitivity, based on liquid culture using microtitre trays. Altogether, the components of this new ‘tool kit’ greatly increase the efficiency of systematic promoter substitutions. Copyright © 2003 John Wiley & Sons, Ltd.