bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo vulnerability to competition by endogenous dopamine: Comparison of the D2 receptor agonist radiotracer (–)‐N‐[11C]propyl‐norapomorphine ([11C]NPA) with the D2 receptor antagonist radiotracer [11C]‐raclopride
Authors: Narendran Rajesh , Hwang Dah‐Ren , Slifstein Mark , Talbot Peter S. , Erritzoe David , Huang Yiyun , Cooper Thomas B. , Martinez Diana , Kegeles Lawrence S. , Abi‐Dargham Anissa , Laruelle Marc 
Published: March 2004

Abstract(–)‐N‐Propyl‐norapomorphine (NPA) is a full dopamine (DA) D2 receptor agonist and [11C]NPA is a suitable radiotracer to image D2 receptors configured in a state of high affinity for agonists with positron emission tomography (PET). In this study the vulnerability of the in vivo binding of [11C]NPA to acute fluctuation in synaptic DA was assessed with PET in baboons and compared to that of the reference D2 receptor antagonist radiotracer [11C]raclopride. Three male baboons were studied with [11C]raclopride and [11C]NPA under baseline conditions and following administration of the potent DA releaser amphetamine (0.3, 0.5, and 1.0 mg kg–1 i.v.). Kinetic modeling with an arterial input function was used to derive the striatal specific‐to‐nonspecific equilibrium partition coefficient (V3″). [11C]Raclopride V3″ was reduced by 24 ± 10%, 32 ± 6%, and 44 ± 9% following amphetamine doses of 0.3, 0.5, and 1.0 mg kg–1, respectively. [11C]NPA V3″ was reduced by 32 ± 2%, 45 ± 3%, and 53 ± 9% following amphetamine doses of 0.3, 0.5, and 1.0 mg kg–1, respectively. Thus, endogenous DA was more effective at competing with [11C]NPA binding compared to [11C]raclopride binding, a finding consistent with the pharmacology of these tracers (agonist vs. antagonist). These results also suggest that 71% of D2 receptors are configured in a state of high affinity for agonists in vivo. In conclusion, [11C]NPA might provide a superior radiotracer to probe presynaptic DA function with PET in health and disease. Synapse 52:188–208, 2004. © 2004 Wiley‐Liss, Inc.
Locomotor sensitization to cocaine in rats with olfactory bulbectomy
Authors: Chambers R. Andrew , Sheehan Teige , Taylor Jane R. 
Published: March 2004

AbstractOlfactory bulbectomy in rats has been suggested as a comprehensive animal model of affective disorders associated with an array of behavioral changes, responsivity to chronic antidepressant treatment, and alterations in limbic structures thought to be critical in the pathophysiology of affective disorders. Recent work showing increased motivational responsivity to amphetamine suggests that olfactory bulbectomy could also be a useful animal model of dual diagnosis disorders. To further investigate this possibility, we studied locomotor activity in olfactory bulbectomized rats 14 days postsurgery in response to novelty and upon acute and repeated injections of cocaine (15/mg/kg) or saline. Consistent with prior studies, lesioned animals showed greater locomotor activity in response to a novel environment and significantly heightened locomotor activation upon initial cocaine exposure. Over 7 days of repeated cocaine injections, lesioned animals also showed a presensitized pattern of activity, with a loss of incremental increases in locomotion observed in control animals. Daily saline injections produced no group differences in pre‐ or postinjection activity, while cocaine‐treated bulbectomized rats demonstrated a decline in their daily preinjection activity. These results suggest that neural alterations caused by olfactory bulbectomy produce altered behavioral response patterns to repeated doses of cocaine, and support the study of olfactory bulbectomy as a useful neurobehavioral model for understanding substance use disorder comorbidity in mental illness. Synapse 52:167–175, 2004. © 2004 Wiley‐Liss, Inc.
Opioid peptide receptor studies. 17. Attenuation of chronic morphine effects after antisense oligodeoxynucleotide knock‐down of RGS9 protein in cells expressing the cloned Mu opioid receptor
Authors: Xu Heng , Wang Xiaoying , Wang Jun , Rothman Richard B. 
Published: March 2004

AbstractRGS proteins are a recently described class of regulators that influence G‐protein‐mediated signaling pathways. We have shown previously that chronic morphine results in functional uncoupling of the μ opioid receptor from its G protein in CHO cells expressing cloned human μ opioid receptors. In the present study, we examined the effects of morphine treatment (1 μM, 20 h) on DAMGO‐stimulated high‐affinity [35S]GTP‐γ‐S binding and DAMGO‐mediated inhibition of forskolin‐stimulated cAMP accumulation in HN9.10 cells stably expressing the cloned rat μ opioid receptor, in the absence and presence of the RGS9 protein knock‐down condition (confirmed by Western blot analysis). RGS9 protein expression was reduced by blocking its mRNA with an antisense oligodeoxynucleotide (AS‐114). Binding surface analysis resolved two [35S]GTP‐γ‐S binding sites (high affinity and low affinity sites). In sense‐treated control cells, DAMGO‐stimulated [35S]GTP‐γ‐S binding by increasing the Bmax of the high‐affinity site. In sense‐treated morphine‐treated cells, DAMGO‐stimulated [35S]GTP‐γ‐S binding by decreasing the high‐affinity Kd without changing the Bmax. AS‐114 significantly inhibited chronic morphine‐induced upregulation of adenylate cyclase activity and partially reversed chronic morphine effects as measured by DAMGO‐stimulated [35S]GTP‐γ‐S binding. Morphine treatment increased the EC50 (6.2‐fold) for DAMGO‐mediated inhibition of forskolin‐stimulated cAMP activity in control cells but not in cells treated with AS‐114 to knock‐down RGS9. These results provide additional evidence for involvement of RGS9 protein in modulating opioid signaling, which may contribute to the development of morphine tolerance and dependence. Synapse 52:209–217, 2004. Published 2004 Wiley‐Liss, Inc.
Intraobserver and interobserver variation in the sonographic grading of placental maturity
Authors: Sau A. , Seed P. , Langford K. 
Published: March 2004

AbstractObjectivesThe appearance of Grannum Grade III changes in the placenta at around 34–36 weeks is a predictor of adverse perinatal outcome, which may be reduced by reporting to the clinician. This has led to the suggestion that the placental grade should be noted during any third‐trimester scan. There are no published data on the reproducibility of sonographic Grannum grading of the placenta; the objective of this study was to evaluate intra‐ and interobserver variation.MethodsFifty‐five placental images from normal and complicated pregnancies of several different gestational ages were collected between April and October 2001. Three fetal medicine consultants and three experienced sonographers graded the images as 0, I, II, III or ungradeable. They then regraded the same images, presented in a different order and with different codes, 4–6 weeks later. Observers were blinded to their previous grading and to each others'. Weighted kappa (κ), with linear weights, was used to look for strength of agreement.ResultsThere was good agreement between the two observations of each placental image for five observers (κ = 0.61 to 0.90), and moderate agreement for one observer (κ = 0.56). However, the κ‐values for comparisons between the 15 pairs of observers ranged from 0.24 to 0.69 with six values below 0.41, indicating only fair agreement. This was confirmed by the overall κ‐value of 0.24 between all six observers. The agreement between the observers for Grade III placenta was poor, with an overall κ‐value of 0.09.ConclusionsAlthough intraobserver agreement was generally good, interobserver agreement was only fair for all grades and poor for Grade III placenta. This may be an indication that Grannum grading is not reproducible or it may reflect a need for training in those performing grading. Such variation may limit the effectiveness of reporting Grannum grades in clinical practice. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Successful intrauterine treatment with radiofrequency ablation in a case of acardiac twin pregnancy complicated with a hydropic pump twin
Authors: Hirose M. , Murata A. , Kita N. , Aotani H. , Takebayashi K. , Noda Y. 
Published: March 2004

AbstractTwin reversed arterial perfusion sequence is a serious complication of monochorionic twin pregnancy, as the pump twin that perfuses blood to the acardiac twin may experience heart failure and fetal hydrops resulting in a poor perinatal outcome. A woman with an acardiac twin pregnancy complicated by a hydropic pump twin underwent intrauterine treatment with radiofrequency ablation (RFA) at 27 weeks of gestation. Obliteration of blood flow to the acardiac twin from the pump twin was successful. Fetal hydrops resolved by the time of delivery at 32 weeks of gestation, in spite of transient deterioration, and a good postnatal outcome was achieved for the pump twin. We found that RFA was an effective intrauterine treatment for acardiac twin pregnancy and suggest that it could be introduced in cases complicated by a hydropic pump twin. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Sonographic detection of fluid collections and postoperative morbidity following Cesarean section and hysterectomy
Authors: Antonelli E. , Morales M. A. , Dumps P. , Boulvain M. , Weil A. 
Published: March 2004

AbstractObjectivesTo evaluate the clinical significance of sonographically detected fluid collections following Cesarean section and hysterectomy, and to identify risk factors associated with their formation.MethodsThis was a prospective study including 280 women, 145 of whom had undergone a Cesarean section and 135 of whom had undergone abdominal or vaginal hysterectomy. Ultrasound examinations were carried out on all women on day 4 after surgery to assess the presence of abdominal wall or pelvic fluid collections. The sonographers were unaware of the clinical course before the examination and were not involved in any clinical decision‐making. Ultrasound findings were correlated with clinical data and postoperative morbidity.ResultsA fluid collection was found in 69 (48%) women after Cesarean section, and in 59 (44%) women who had undergone hysterectomy. No risk factors for the development of fluid collections after Cesarean section or hysterectomy were identified. The risk of developing febrile morbidity was not related to the presence, location or size of fluid collections.ConclusionsPostoperative fluid collections are common after Cesarean section and hysterectomy. As fluid collections detected by sonography were not associated with postoperative morbidity, this finding is unlikely to be useful in the workup for postoperative fever. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Umbilical cord serum vascular endothelial growth factor (VEGF) levels in normal pregnancies and in pregnancies complicated by preterm delivery or pre‐eclampsia
Authors: Galazios G. , Papazoglou D. , Giagloglou K. , Vassaras G. , Koutlaki N. , Maltezos E. 
Published: March 2004

AbstractObjectives: The aim of this study was to determine whether increased levels of vascular endothelial growth factor (VEGF) are implicated in the pathogenesis of pre‐eclampsia and in preterm delivery. Methods: Umbilical cord serum VEGF levels from women with uncomplicated term pregnancies (control group, n=24), with pregnancies complicated by pre‐eclampsia (n=21), or with preterm delivery (n=29) were compared. Statistical analysis was performed using the Mann–Whitney U‐test, the t‐test, and Smirnoff–Kolmogorov test. Results: The mean VEGF concentration was significantly higher in the women with pre‐eclampsia than in women from the control group (P<0.01). There were also increased but not significantly higher VEGF concentrations in the preterm delivery group compared with the control group (P=0.16). Conclusions: Our study results support previous findings that raised umbilical cord serum VEGF levels might be correlated with the clinical development of pre‐eclampsia and, in some circumstances, of preterm delivery.
Balloon mitral valvuloplasty during pregnancy
Authors: Routray S.N. , Mishra T.K. , Swain S. , Patnaik U.K. , Behera M. 
Published: March 2004

AbstractObjectives: Balloon mitral valvuloplasty (BMV) has been performed safely during pregnancy with good results. Reports are few on long‐term effects of BMV on childhood development. Methods: BMV was performed in 40 pregnant women (age 23.4±4.8 years) with severe mitral stenosis at 24.2±4.6 weeks of gestation. Results: Mitral valve area increased from 0.82±0.34 to 1.9±0.4 cm2 (P<0.001). One patient had pericardial tamponade. Mean fluoroscopy time was 5.5±3.8 min. There was no maternal death, no abortion, no intrauterine growth restriction and one stillbirth. All 39 babies were normal at birth. One baby died at 7 months due to pneumonia. On follow up for 36±15 months, all 38 babies maintained normal growth and development without any thyroid disease or malignancy. Conclusions: During pregnancy BMV is feasible, safe and effective. Maternal and fetal outcomes are excellent. Growth and milestone of development are not affected.
The effects of lumbosacral orthoses on spine stability: What changes in EMG can be expected?
Authors: Cholewicki Jacek 
Published: March 2004

AbstractAntagonistic trunk muscle activity is normally required to stabilize the spine. A lumbosacral orthosis (LSO) might reduce the need for this antagonistic activity by providing passive stiffness to the trunk and increasing spine stability. The maximum reduction in trunk muscle EMG and in the resultant spine compression force due to the LSO was estimated using a biomechanical model. The lumbar spine stability was first quantified for the average trunk muscle EMG recorded from 11 male subjects performing various isometric trunk exertion tasks. Subsequently, the spine‐stiffening effects of the LSO were implemented in the model and trunk muscle forces were reduced iteratively until the original level of spine stability without the LSO was achieved. The upper bound estimates of the reduction in trunk muscle EMG due to LSO ranged from 0.6% to 14.1% of the maximum voluntary activation depending on the task and the muscle. The resultant spine compression force averaged across all tasks decreased by only 355 N. A much larger variance of the experimental data precluded the detection of these effects at statistically significant levels. However, the small effects size does not necessarily exclude the possibility of functional benefits of slightly reducing muscle activity in patients with low back pain. © 2004 Orthopaedic Research Society. Published y Elsevier Ltd. All rights reserved.
Interactive journal concept for improved scientific publishing and quality assurance
Authors: Pöschl Ulrich 
Published: March 2004

ABSTRACTMany scientific publications are careless, useless or false, and inhibit scholarly communication and scientific progress. This is caused by the failure of traditional journal publishing and peer review to provide efficient scientific exchange and quality assurance in today's highly diverse world of science. The most promising way to improve matters is a two‐stage (or multi‐stage) publication processes with interactive peer review and public discussion in new and traditional scientific journals. A concept for such interactive scientific journals is outlined, and its applicability is demonstrated by the open access journal Atmospheric Chemistry and Physics.
Book Reviews
Authors: Halsall Janet , Smart Pippa , Watkinson Anthony 
Published: March 2004

Indexing and Abstracting in Theory and Practice, 3rd edn, by F. W. Lancaster Facet Publishing 2003, 464 pp., ISBN 1‐85604‐482‐3, £39.95Science Editors' Handbook European Association of Science Editors 2003, ISBN 0‐905988‐13‐2, £18Digital Preservation: The Record of Science, edited by Barry Mahon and Elliot Siegel IOS Press, 2002, 143 pp., ISBN 1‐58603‐317‐4, paperback £65.00
Synaptic P2X7 and Oxygen/Glucose Deprivation in Organotypic Hippocampal Cultures
Authors: Cavaliere Fabio , Amadio Susanna , Sancesario Giuseppe , Bernardi Giorgio , Volonté Cinzia 
Published: March 2004

The P2X7 receptor for extracellular ATP is the main candidate, among P2 receptors, inducing cell death in the immune system. Here, we demonstrate the direct participation of this receptor to cell damage induced by oxygen/glucose deprivation, in the ex vivo model of organotypic hippocampal cultures. By pharmacological and immunological approaches, we show that P2X7 is rapidly and transiently up regulated in hippocampal areas eliciting metabolism impairment. Moreover, the P2 antagonists 2′,3′,-dialdehyde ATP and reactive blue 2 prevent both up regulation of this receptor and hypoxic/hypoglycemic damage. By confocal laser microscopy, we show that P2X7 is present at the synaptic level of fibers extending from the CA1–2 pyramidal cell layer throughout the strata oriens and radiatum, but absent on oligodendrocytes, astrocytes or neuronal cell bodies. Colocalization of P2X7 is obtained with neurofilament-L protein and with synaptophysin, not with myelin basic protein, glial fibrillary acidic protein or a marker for neuronal nuclei. P2X7 up regulation and diffuse cellular damage are also induced by 3′-O-(4-benzoyl) benzoyl-ATP, an agonist selective but not exclusive for P2X7. In summary, our study demonstrates that P2X7 not only directly participates to the hypoxic/hypoglycemic process, but also owns specific phenotypic localization. We do not exclude that it might serve as a sensor of dysregulated neuronal activity and ATP release, both occurring during oxygen/glucose deprivation.
Intermediates and the folding of proteins L and G
Authors: Brown Scott , Head‐Gordon Teresa 
Published: March 2004

AbstractWe use a minimalist protein model, in combination with a sequence design strategy, to determine differences in primary structure for proteins L and G, which are responsible for the two proteins folding through distinctly different folding mechanisms. We find that the folding of proteins L and G are consistent with a nucleation‐condensation mechanism, each of which is described as helix‐assisted β‐1 and β‐2 hairpin formation, respectively. We determine that the model for protein G exhibits an early intermediate that precedes the rate‐limiting barrier of folding, and which draws together misaligned secondary structure elements that are stabilized by hydrophobic core contacts involving the third β‐strand, and presages the later transition state in which the correct strand alignment of these same secondary structure elements is restored. Finally, the validity of the targeted intermediate ensemble for protein G was analyzed by fitting the kinetic data to a two‐step first‐order reversible reaction, proving that protein G folding involves an on‐pathway early intermediate, and should be populated and therefore observable by experiment.
Alignment of protein sequences by their profiles
Authors: Marti‐Renom Marc A. , Madhusudhan M.S. , Sali Andrej 
Published: March 2004

AbstractThe accuracy of an alignment between two protein sequences can be improved by including other detectably related sequences in the comparison. We optimize and benchmark such an approach that relies on aligning two multiple sequence alignments, each one including one of the two protein sequences. Thirteen different protocols for creating and comparing profiles corresponding to the multiple sequence alignments are implemented in the SALIGN command of MODELLER. A test set of 200 pairwise, structure‐based alignments with sequence identities below 40% is used to benchmark the 13 protocols as well as a number of previously described sequence alignment methods, including heuristic pairwise sequence alignment by BLAST, pairwise sequence alignment by global dynamic programming with an affine gap penalty function by the ALIGN command of MODELLER, sequence‐profile alignment by PSI‐BLAST, Hidden Markov Model methods implemented in SAM and LOBSTER, pairwise sequence alignment relying on predicted local structure by SEA, and multiple sequence alignment by CLUSTALW and COMPASS. The alignment accuracies of the best new protocols were significantly better than those of the other tested methods. For example, the fraction of the correctly aligned residues relative to the structure‐based alignment by the best protocol is 56%, which can be compared with the accuracies of 26%, 42%, 43%, 48%, 50%, 49%, 43%, and 43% for the other methods, respectively. The new method is currently applied to large‐scale comparative protein structure modeling of all known sequences.
Conformational mapping of the N‐terminal peptide of HIV‐1 gp41 in lipid detergent and aqueous environments using 13C‐enhanced Fourier transform infrared spectroscopy
Authors: Gordon Larry M. , Mobley Patrick W. , Lee William , Eskandari Sepehr , Kaznessis Yiannis N. , Sherman Mark A. , Waring Alan J. 
Published: March 2004

AbstractThe N‐terminal domain of HIV‐1 glycoprotein 41,000 (gp41) participates in viral fusion processes. Here, we use physical and computational methodologies to examine the secondary structure of a peptide based on the N terminus (FP; residues 1–23) in aqueous and detergent environments. 12C‐Fourier transform infrared (FTIR) spectroscopy indicated greater α‐helix for FP in lipid‐detergent sodium dodecyl sulfate (SDS) and aqueous phosphate‐buffered saline (PBS) than in only PBS. 12C‐FTIR spectra also showed disordered FP conformations in these two environments, along with substantial β‐structure for FP alone in PBS. In experiments that map conformations to specific residues, isotope‐enhanced FTIR spectroscopy was performed using FP peptides labeled with 13C‐carbonyl. 13C‐FTIR results on FP in SDS at low peptide loading indicated α‐helix (residues 5 to 16) and disordered conformations (residues 1–4). Because earlier 13C‐FTIR analysis of FP in lipid bilayers demonstrated α‐helix for residues 1–16 at low peptide loading, the FP structure in SDS micelles only approximates that found for FP with membranes. Molecular dynamics simulations of FP in an explicit SDS micelle indicate that the fraying of the first three to four residues may be due to the FP helix moving to one end of the micelle. In PBS alone, however, electron microscopy of FP showed large fibrils, while 13C‐FTIR spectra demonstrated antiparallel β‐sheet for FP (residues 1–12), analogous to that reported for amyloid peptides. Because FP and amyloid peptides each exhibit plaque formation, α‐helix to β‐sheet interconversion, and membrane fusion activity, amyloid and N‐terminal gp41 peptides may belong to the same superfamily of proteins.