bluuebunny/crossref_metadata_2025_split huggingface dataset:
HDPE‐Al2O3‐HAp composites for biomedical applications: Processing and characterizations
Authors: Nath Shekhar , Bodhak Subhadip , Basu Bikramjit 
Published: March 2008

AbstractThe objective of this work is to demonstrate how the stiffness, hardness, as well as the biocompatibility property, of bioinert high‐density polyethylene (HDPE) can be significantly improved by the combined addition of both bioinert and bioactive ceramic fillers. For this purpose, different volume fractions of hydroxyapatite and alumina, limited to a total of 40 vol %, have been incorporated in HDPE matrix. All the hybrid composites and monolithic HDPE were developed under optimized hot pressing condition (130°C, 0.5 h, 92MPa pressure). The results of the mechanical property characterization reveal that higher elastic modulus (6.2 GPa) and improved hardness (226.5 MPa) could be obtained in the developed HDPE‐20 vol %‐HAp‐20 vol % Al2O3 composite. Under the selected fretting conditions against various counterbody materials (steel, Al2O3, and ZrO2), an extremely low COF of (0.07–0.11) and higher wear resistance (order of 10−6 mm3/Nm) are obtained with the HDPE/20 vol % HAp/20 vol % Al2O3 composite in both air and simulated body fluid environment. Importantly, in‐vitro cell culture study using L929 fibroblast cells confirms favorable cell adhesion properties in the developed hybrid composite. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Mandibular arch muscle identity is regulated by a conserved molecular process during vertebrate development
Authors: Knight Robert D. , Mebus Katharina , Roehl Henry H. 
Published: March 2008

AbstractVertebrate head muscles exhibit a highly conserved pattern of innervation and skeletal connectivity and yet it is unclear whether the molecular basis of their development is likewise conserved. Using the highly conserved expression of Engrailed 2 (En2) as a marker of identity in the dorsal mandibular muscles of zebrafish, we have investigated the molecular signals and tissues required for patterning these muscles. We show that muscle En2 expression is not dependent on signals from the adjacent neural tube, pharyngeal endoderm or axial mesoderm and that early identity of head muscles does not require bone morphogenetic pathway, Notch or Hedgehog (Hh) signalling. However, constrictor dorsalis En2 expression is completely lost after a loss of fibroblast growth factor (Fgf) signalling and we show that is true throughout head muscle development. These results suggest that head muscle identity is dependent on Fgf signalling. Data from experiments performed in chick suggest a similar regulation of En2 genes by Fgf signalling revealing a conserved mechanism for specifying head muscle identity. We present evidence that another key gene important in the development of mouse head muscles, Tbx1, is also critical for specification of mandibular arch muscle identity and that this is independent of Fgf signalling. These data imply that dorsal mandibular arch muscle identity in fish, chick and mouse is specified by a highly conserved molecular process despite differing functions of these muscles in different lineages. J. Exp. Zool. (Mol. Dev. Evol.) 310B:355–369, 2008. © 2008 Wiley‐Liss, Inc.
Enantiomeric radiochemical synthesis of R and S (1‐(6‐amino‐9H‐purin‐9‐yl)‐3‐fluoropropan‐2‐yloxy)methylphosphonic acid (FPMPA)
Authors: Kiesewetter Dale O. , Knudson Kathleen , Collins Matt , Srinivasula Sharat , Lim Esther , Di Mascio Michele 
Published: March 2008

AbstractTherapy for human immunodeficiency virus (HIV)‐infected patients requires chronic multidrug administration. The eventual failure of therapy in some patients has brought into question the tissue concentration of the drugs. With an appropriately radiolabeled compound, we could utilize positron emission tomography to provide quantitative time–activity curves for various tissues. We have developed a fluorine‐18 labeled analog of Tenofovir, the active metabolite of Tenofovir DF, a commonly prescribed component of multidrug therapy. Because (1‐(6‐amino‐9H‐purin‐9‐yl)‐3‐fluoropropan‐2‐yloxy)methylphosphonic acid (FPMPA) has a chiral center, we prepared both enantiomers and confirmed that the S‐isomer exhibited significantly higher antiviral activity than the R‐isomer. In viral replication inhibition assays in human MT4 cells infected with SHIVDH12R, S‐FPMPA had an IC50 of 1.85 µM (95% CI; 0.8–5.53), while the R‐isomer was inactive. An appropriate chiral precursor was prepared to allow the incorporation of fluorine‐18. The [18F]FPMPA in racemic, R, or S form was prepared in a 50 min synthesis in 38±5% yield (n=23, corrected for decay). The product was of high radiochemical and enantiomeric purity. The specific activity of the final product was 4.0±1.8 Ci/µmol at EOB (end of bombardment). This product may provide information about drug tissue distribution in animal models under chronic drug treatment. Copyright © 2008 John Wiley & Sons, Ltd.
Cell‐specific actions of HIV‐Tat and morphine on opioid receptor expression in glia
Authors: Turchan‐Cholewo Jadwiga , Dimayuga Filomena O. , Ding Qunxing , Keller Jeffrey N. , Hauser Kurt F. , Knapp Pamela E. , Bruce‐Keller Annadora J. 
Published: March 2008

AbstractHIV‐1 patients who abuse opiate‐based drugs, including heroin and morphine, are at a higher risk of developing HIV dementia. The effects of opiates are mediated predominantly through opioid receptors, which are expressed on glial cells. As HIV‐1 infection in the CNS is restricted to glial cells, experiments were designed to measure the cell‐specific effects of HIV Tat and morphine exposure on opioid receptor expression in both astrocytes and microglia. Specifically, the cell‐type‐specific pattern of mu opioid receptor (MOR), delta opioid receptor (DOR), and kappa opioid receptor (KOR) localization (surface vs. intracellular) and expression of opioid receptor mRNA were determined after exposure to morphine in the presence and the absence of Tat in primary cultured microglia and astrocytes. Data show that morphine treatment caused significantly decreased cell surface expression of opioid receptors in microglia but not in astrocytes. However, morphine treatment in the presence of Tat significantly increased intracellular expression of opioid receptors and prevented morphine‐induced cell surface opioid receptor down‐regulation in microglia. These findings document that cell surface opioid receptor expression is divergently regulated by morphine in microglia compared with in astrocytes, and further suggest that HIV‐Tat could exacerbate opioid receptor signaling in microglia by increasing receptor expression and/or altering ligand‐induced trafficking of opioid receptors. © 2008 Wiley‐Liss, Inc.
Regional‐specific regulation of BDNF and trkB correlates with nigral dopaminergic cell sprouting following unilateral nigrostriatal axotomy
Authors: Navia J. T. García , Burguillos M. A. , Ramón‐Cueto A. , Machado A. , Cano J. , Venero J. L. 
Published: March 2008

AbstractAxotomy is a powerful stimulus of axon growth and plastic changes. We investigated the potential role of BDNF/trkB signaling in the sprouting of dopaminergic nigral axons in response to axotomy of the medial forebrain bundle. Tyrosine hydroxylase immunohistochemistry revealed the existence of sprouting mechanisms in the axotomized substantia nigra (SN). Time‐course changes of trkB mRNA expression demonstrated a robust increase in an area projecting from the rostral tip of the SN to the glial scar, which coincided with evidence of nigral dopaminergic sprouting. In addition, we found an early loss of this messenger in areas related to the knife cut, which recovered by 7 days postlesion. TrkB down‐regulation appeared to be associated to the lesion‐induced local damage, as it was restricted to an area showing Fluoro‐Jade B– and TUNEL positive cells. In trkB‐depleted areas, an inverse correlation between mRNA expressions of BDNF and trkB was apparent. Specific induction of BDNF mRNA was mostly seen in border of areas devoid of trkB mRNA. In contrast, in the areas exhibiting trkB mRNA expression, no BDNF mRNA was detected. We suggest that trkB levels could be a determinant element in regulating BDNF expression. Finally, the search for molecules involved in either promoting or inhibiting axonal growth, demonstrated up‐regulation of GAP‐43 and Nogo‐A mRNA at sites close to the knife transections as early as 1 day postlesion. However, overall, Nogo‐A induction was more robust than that seen for GAP‐43. © 2008 Wiley‐Liss, Inc.
Pivotal role of early B‐cell factor 1 in development of striatonigral medium spiny neurons in the matrix compartment
Authors: Lobo Mary Kay , Yeh Christopher , Yang X. William 
Published: March 2008

AbstractThe mammalian striatum plays a critical function in motor control, motor and reward learning, and cognition. Dysfunction and degeneration of the striatal neurons are implicated in major neurological and psychiatric disorders. The vast majority of striatal neurons are medium spiny neurons (MSNs). MSNs can be further subdivided into distinct subtypes based on their physical localization in the striatal patch vs. matrix compartments and based on their axonal projections and marker gene expression (i.e., striatonigral MSNs vs. striatopallidal MSNs). Despite our extensive knowledge on the striatal cytoarchitecture and circuitry, little is known about the molecular mechanisms controlling the development of the MSN subtypes in the striatum. Early B‐cell factor 1 (Ebf1) is a critical transcription factor implicated in striatal MSN development. One study shows that Ebf1 is critical for the differentiation of MSNs in the matrix, and our separate study demonstrates that Ebf1 is selectively expressed in the striatonigral MSNs and is essential for their postnatal differentiation. In the present study, we further validate the striatonigral MSN deficits in Ebf1−/− mice using multiple striatonigral MSN reporter mice. Moreover, we demonstrate that the striatonigral MSN deficits in these mice are restricted to those in the matrix, with relative sparing of those in the patch. Finally, we demonstrate that Ebf1 deficiency also results in reduced expression of another striatonigral‐specific transcription factor, zinc finger binding protein 521 (Zfp521), which is a known Ebf1 functional partner. Overall, our study reveals that Ebf1 may play an essential role in controlling the differentiation of the striatonigral MSNs in the matrix compartment. © 2008 Wiley‐Liss, Inc.
Decreased drebrin mRNA expression in Alzheimer disease: Correlation with tau pathology
Authors: Julien Carl , Tremblay Cyntia , Bendjelloul Farid , Phivilay Alix , Coulombe Marie‐Andrée , Émond Vincent , Calon Frédéric 
Published: March 2008

AbstractTo investigate the mRNA expression of the dendritic spine protein drebrin in Alzheimer's disease (AD), we performed post‐mortem in situ hybridization studies in brain sections from 20 AD patients and 21 controls. AD diagnosis was confirmed by decreased drebrin protein and increased Aβ40 (+464%; P < 0.05), Aβ42 (+369%; P < 0.0001), Aβ42/40 ratio (+226%; P < 0.01), total tau (+2,725%; P < 0.0001), and paired helical filament tau (PHFtau; +867%; P < 0.001) compared with controls. We found significant decreases in drebrin mRNA in the parietal cortex (–27%; P < 0.01), the temporal cortex (–22%; P < 0.05), and the hippocampus (–25%; P < 0.05) of AD patients compared with controls. Cortical levels of drebrin mRNA correlated positively with soluble total tau (r2 = +0.244) but negatively with duration of symptoms (r2 = −0.357) and PHFtau (r2 = −0.248). Drebrin mRNA levels were correlated to a lesser degree with the drebrin protein content (r2 = +0.136) and with sim2 (r2 = +0.176), a potential modulator of drebrin transcription. Our results suggest that the down‐regulation of drebrin mRNA expression plays an important role in AD and is closely related to the progression of the disease. © 2008 Wiley‐Liss, Inc.
Determination of montelukast sodium by capillary electrophoresis
Authors: Shakalisava Yuliya , Regan Fiona 
Published: March 2008

AbstractThis work verifies the potential of CE in the analysis of significant impurities of montelukast sodium – an active ingredient for the treatment of bronchial asthma. Using 20 mM borate buffer pH 9.2 with 10 mM SDS and 10 mM (2‐hydroxypropyl)‐γ‐CD (2HP‐γ‐CD) it was possible to separate montelukast and several impurities, including its cis‐isomer, after exposure to light and oxygen. The obtained method surpasses a chromatographic method for montelukast sodium in terms of time of analysis (9 min of CE analysis vs. 35 min HPLC) and efficiency (CE offered over 900 000 theoretical plates for montelukast). Good repeatability of the method was supported by the low % RSD for the migration time of montelukast (0.53%). For the first time, the capillary electrophoretic method was employed for temporal study of the degradation of montelukast. The results showed that degradation of montelukast and the formation of the cis‐isomer mainly occurred during the first 2 days of exposure, and occurred to a higher degree when there was no contact with the air (oxygen) in the exposed sample.
Determination of triazine herbicides in fruits and vegetables using dispersive solid‐phase extraction coupled with LC–MS
Authors: Ji Feng , Zhao Lixia , Yan Wei , Feng Qinzhong , Lin Jin‐Ming 
Published: March 2008

AbstractA simple, rapid, and sensitive liquid chromatography–mass spectrometry (LC–MS) method was successfully developed for the determination of three chloro‐s‐triazine herbicides, viz. atrazine, simazine, and propazine, two thiomethyl‐s‐triazine ones, viz. ametryn and prometryn, and prometon in fruits and vegetables. The instrumental parameters affecting LC separation and MS detection were investigated and the best conditions were selected. Samples were extracted and purified by dispersive solid‐phase extraction (dispersive‐SPE) with a primary‐secondary amine sorbent. Three typical representative samples (luffa, broad bean, and grape) were selected to investigate the effect of different matrices on pesticide recoveries and assay precision after spiking at 0.05 mg/kg. Matrix composition did not interfere significantly with the determination of these pesticides. The recoveries were, with a few exceptions, in the range of 80–110% with relative standard deviations less than 10% (n = 5). In addition, this method was also applied to 21 different kinds of agriculture products collected from the local market, and two of the six triazines could be detected and quantified.
β‐Sitosterol enhances tamoxifen effectiveness on breast cancer cells by affecting ceramide metabolism
Authors: Awad Atif B. , Barta Stephanie L. , Fink Carol S. , Bradford Peter G. 
Published: March 2008

AbstractThe objective of this study was to investigate the effects of the dietary phytosterol β‐sitosterol (SIT) and the antiestrogen drug tamoxifen (TAM) on cell growth and ceramide (CER) metabolism in MCF‐7 and MDA‐MB‐231 human breast cancer cells. The MCF‐7 and MDA‐MB‐231 cell lines were studied as models of estrogen receptor positive and estrogen receptor negative breast cancer cells. Growth of both cell lines as determined using the sulforhodamine B assay was inhibited by treatment with 16 μM SIT but only MCF‐7 cell growth was inhibited by treatment with 1 μM TAM. The combination of SIT and TAM further inhibited growth in both cell lines, most significantly in MDA‐MB‐231 cells. CER is a proapoptotic signal and CER levels were increased in both MCF‐7 and MDA‐MB‐231 cells by individual treatment with SIT and TAM and the combined treatment raised cellular CER content even further. SIT and TAM raised CER levels by different means. SIT potently activatedde novoCER synthesis in both MCF‐7 and MDA‐MB‐231 cells by stimulating serine palmitoyltransferase activity; whereas TAM promoted CER accumulation in both cell types by inhibiting CER glycosylation. These results suggest that the combination regimen of dietary SIT and TAM chemotherapy may be beneficial in the management of breast cancer patients.
Legumin allergens from peanuts and soybeans: Effects of denaturation and aggregation on allergenicity
Authors: van Boxtel Evelien L. , van den Broek Lambertus A. M. , Koppelman Stef J. , Gruppen Harry 
Published: March 2008

AbstractLegumin proteins Ara h 3 from peanuts and glycinin from soybeans are increasingly described as important allergens. The stability of an allergen's IgE binding capacity towards heating and digestion is considered an important characteristic for food allergens. We investigated the effects of heating and digestion on the IgE binding of Ara h 3 and glycinin. Both proteins are relatively stable to denaturation, having denaturation temperatures ranging from 70 to 92°C, depending on their quaternary structure and the ionic strength. Aggregates were formed upon heating, which were partly soluble for glycinin. Heating slightly decreased the pepsin digestion rate of both allergens. However, heating did not affect the IgE binding capacity of the hydrolyzates, as after only 10 min of hydrolysis no IgE binding could be detected any more in all samples. Peanut allergen Ara h 1, when digested under equal conditions, still showed IgE binding after 2 h of hydrolysis. Our results indicate that the IgE binding capacity of legumin allergens from peanuts and soybeans does not withstand peptic digestion. Consequently, these allergens are likely unable to sensitize via the gastro‐intestinal tract and cause systemic food allergy symptoms. These proteins might thus be less important allergens than was previously assumed.
1H and 13C NMR assignments for 6‐demethylvermistatin and two penicillide derivatives from the mangrove fungus Guignardia sp. (No. 4382) from the South China Sea
Authors: Xia Xue‐kui , liu Fan , She Zhi‐gang , Yang Li‐guo , Li Meng‐feng , Vrijmoed L. L. P. , Lin Yong‐cheng 
Published: March 2008

AbstractOne new compound 6‐demethylvermistatin (1), together with two known compounds, the penicillide derivatives (2) and (3) were isolated from the mangrove fungus Guignardia sp. No. 4382 obtained from the South China Sea. Their structures were assigned using high‐resolution electron ionization mass spectrometry(HREIMS), 1H and 13C NMR spectra, DEPT, and by 2D COSY, HMQC, and HMBC experiments. The absolute configuration of 1 was established by comparison of its CD with that of vermistatin. Copyright © 2008 John Wiley & Sons, Ltd.
Presidential address: How to improve poverty measurement in the United States
Authors: Blank Rebecca M. 
Published: March 2008

AbstractThis paper discusses the reasons why the current official U.S. poverty measure is outdated and nonresponsive to many anti‐poverty initiatives. A variety of efforts to update and improve the statistic have failed, for political, technical, and institutional reasons. Meanwhile, the European Union is taking a very different approach to poverty measurement. The paper ends with four recommended steps that would allow the U.S. to improve its measurement of poverty and economic need.
Impacts of abstinence education on teen sexual activity, risk of pregnancy, and risk of sexually transmitted diseases
Authors: Trenholm Christopher , Devaney Barbara , Fortson Kenneth , Clark Melissa , Quay Lisa , Wheeler Justin 
Published: March 2008

AbstractThis paper examines the impacts of four abstinence‐only education programs on adolescent sexual activity and risks of pregnancy and sexually transmitted diseases (STDs). Based on an experimental design, the impact analysis uses survey data collected in 2005 and early 2006 from more than 2,000 teens who had been randomly assigned to either a program group that was eligible to participate in one of the four programs or a control group that was not. The findings show no significant impact on teen sexual activity, no differences in rates of unprotected sex, and some impacts on knowledge of STDs and perceived effectiveness of condoms and birth control pills.© 2008 by the Association for Public Policy Analysis and Management.
Reassessing the WIC effect: Evidence from the Pregnancy Nutrition Surveillance System
Authors: Joyce Ted , Racine Andrew , Yunzal‐Butler Cristina 
Published: March 2008

AbstractRecent analyses differ on how effective the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) is at improving infant health. We use data from nine states that participate in the Pregnancy Nutrition Surveillance System to address limitations in previous work. With information on the mother's timing of WIC enrollment, we test whether greater exposure to WIC is associated with less smoking, improved weight gain during pregnancy, better birth outcomes, and greater likelihood of breastfeeding. Our results suggest that much of the often reported association between WIC and lower rates of preterm birth is likely spurious, the result of gestational age bias. We find modest effects of WIC on fetal growth, inconsistent associations between WIC and smoking, limited associations with gestational weight gain, and some relationship with breastfeeding. A WIC effect exists, but on fewer margins and with less impact than has been claimed by policy analysts and advocates. © 2008 by the Association for Public Policy Analysis and Management.
Demand for masters of public policy in public service
Authors: Evans Angela M. 
Published: March 2008

AbstractThis piece was written to assist those who lead schools of public policy and administration in evaluating their pedagogies and examining their curricula. The perspectives contained in this piece reflect those of the author, who has spent the last 35 years practicing and leading public policy research and analysis in the Congressional Research Service (CRS)—the public policy agency created by the U.S. Congress for its exclusive use. The views expressed here do not necessarily reflect those of CRS or the Congress.
Reliability of the assessment of preventable adverse drug events in daily clinical practice
Authors: van Doormaal Jasperien E. , Mol Peter G. M. , van den Bemt Patricia M. L. A. , Zaal Rianne J. , Egberts Antoine C. G. , Kosterink Jos G. W. , Haaijer‐Ruskamp Flora M. 
Published: March 2008

AbstractPurposeTo determine the reliability of the assessment of preventable adverse drug events (ADEs) in daily practice and to explore the impact of the assessors' professional background and the case characteristics on reliability.MethodsWe used a combination of the simplified Yale algorithm and the National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP) scheme to assess on the one hand the causal relationship between medication errors (MEs) and adverse events in hospitalised patients and on the other hand the severity of the clinical consequence of MEs. Five pharmacists and five physicians applied this algorithm to 30 potential MEs. After individual assessment, the pharmacists reached consensus and so did the physicians. Outcome was both MEs' severity (ordinal scale, NCC MERP categories A–I) and the occurrence of preventable harm (binary outcome, NCC MERP categories A–D vs. E–I). Kappa statistics was used to assess agreement.ResultsThe overall agreement on MEs' severity was fair for the pharmacists (κ = 0.34) as well as for the physicians (κ = 0.25). Overall agreement for the 10 raters was fair (κ = 0.25) as well as the agreement between both consensus outcomes (κ = 0.30). Agreement on the occurrence of preventable harm was higher, ranging from κ = 0.36 for the physicians through κ = 0.49 for the pharmacists. Overall agreement for the 10 raters was fair (κ = 0.36). The agreement between both consensus outcomes was moderate (κ = 0.47). None of the included case characteristics had a significant impact on agreement.ConclusionsIndividual assessment of preventable ADEs in real patients is difficult, possibly because of the difficult assessment of contextual information. Best approach seems to be a consensus method including both pharmacists and physicians. Copyright © 2008 John Wiley & Sons, Ltd.