bluuebunny/crossref_metadata_2025_split huggingface dataset:
CCAAT/enhancer binding protein ϵ: changes in function upon phosphorylation by p38 MAP kinase
Authors: Williamson Elizabeth A. , Williamson Ian K. , Chumakov Alexey M. , Friedman Alan D. , Koeffler H. Phillip 
Published: January 2005

AbstractC/EBPϵ, a member of the CCAAT/enhancer binding protein family, is a transcription factor important in neutrophil differentiation. We have determined that it is phosphorylated on multiple serine and threonine residues and can be a target for phosphorylation by a number of kinases. We identified a threonine at amino acid 75, part of a consensus mitogen-activated protein (MAP) kinase site within the transactivation domain of C/EBPϵ, as being phosphorylated only by p38 MAP kinase. Phosphorylation of this residue resulted in enhanced transcriptional activity on a myeloid-specific promoter in in vitro transient transfection reporter assays. We also determined that phosphorylation at Thr75 yielded a protein that was more effective at binding its cognate DNA sequence compared with the wild-type nonphosphorylated C/EBPϵ. Stable expression of C/EBPϵT75A in interleukin 3 (IL-3)–dependent 32Dcl3 did not result in the up-regulation of expression of secondary granule genes compared with wild-type C/EBPϵ or C/EBPϵT75D. Therefore we suggest that C/EBPϵ is a target for p38 MAP kinase activity.
Bayesian and maximum likelihood phylogenetic analyses of protein sequence data under relative branch-length differences and model violation
Authors: Mar Jessica C , Harlow Timothy J , Ragan Mark A 
Published: January 2005

Abstract
Background
Bayesian phylogenetic inference holds promise as an alternative to maximum likelihood, particularly for large molecular-sequence data sets. We have investigated the performance of Bayesian inference with empirical and simulated protein-sequence data under conditions of relative branch-length differences and model violation.

Results
With empirical protein-sequence data, Bayesian posterior probabilities provide more-generous estimates of subtree reliability than does the nonparametric bootstrap combined with maximum likelihood inference, reaching 100% posterior probability at bootstrap proportions around 80%. With simulated 7-taxon protein-sequence datasets, Bayesian posterior probabilities are somewhat more generous than bootstrap proportions, but do not saturate. Compared with likelihood, Bayesian phylogenetic inference can be as or more robust to relative branch-length differences for datasets of this size, particularly when among-sites rate variation is modeled using a gamma distribution. When the (known) correct model was used to infer trees, Bayesian inference recovered the (known) correct tree in 100% of instances in which one or two branches were up to 20-fold longer than the others. At ratios more extreme than 20-fold, topological accuracy of reconstruction degraded only slowly when only one branch was of relatively greater length, but more rapidly when there were two such branches. Under an incorrect model of sequence change, inaccurate trees were sometimes observed at less extreme branch-length ratios, and (particularly for trees with single long branches) such trees tended to be more inaccurate. The effect of model violation on accuracy of reconstruction for trees with two long branches was more variable, but gamma-corrected Bayesian inference nonetheless yielded more-accurate trees than did either maximum likelihood or uncorrected Bayesian inference across the range of conditions we examined. Assuming an exponential Bayesian prior on branch lengths did not improve, and under certain extreme conditions significantly diminished, performance. The two topology-comparison metrics we employed, edit distance and Robinson-Foulds symmetric distance, yielded different but highly complementary measures of performance.

Conclusions
Our results demonstrate that Bayesian inference can be relatively robust against biologically reasonable levels of relative branch-length differences and model violation, and thus may provide a promising alternative to maximum likelihood for inference of phylogenetic trees from protein-sequence data.
Home visits by family physicians during the end-of-life: Does patient income or residence play a role?
Authors: Burge Frederick I , Lawson Beverley , Johnston Grace 
Published: January 2005

Abstract
Background
With a growing trend for those with advanced cancer to die at home, there is a corresponding increase in need for primary medical care in that setting. Yet those with lower incomes and in rural regions are often challenged to have their health care needs met. This study examined the association between patient income and residence and the receipt of Family Physician (FP) home visits during the end-of-life among patients with cancer.

Methods
Data Sources/Study Setting. Secondary analysis of linked population-based data. Information pertaining to all patients who died due to lung, colorectal, breast or prostate cancer between 1992 and 1997 (N = 7,212) in the Canadian province of Nova Scotia (NS) was extracted from three administrative health databases and from Statistics Canada census records. Study Design. An ecological measure of income ('neighbourhood' median household income) was developed using census information. Multivariate logistic regression was then used to assess the association of income with the receipt of at least one home visit from a FP among all subjects and by region of residency during the end-of-life. Covariates in the initial multivariate model included patient demographics and alternative health services information such as total days spent as a hospital inpatient. Data Extraction Methods. Encrypted patient health card numbers were used to link all administrative health databases whereas the postal code was the link to Statistics Canada census information.

Results
Over 45% of all subjects received at least one home visit (n = 3265). Compared to those from low income areas, the log odds of receiving at least one home visit was significantly greater among subjects who reside in middle to high income neighbourhoods (for the highest income quintile, adjusted odds ratio [OR] = 1.37, 95% confidence interval [CI] = 1.15, 1.64; for upper-middle income, adjusted OR = 1.19, 95%CI = 1.02, 1.39; for middle income, adjusted OR = 1.33, 95%CI = 1.15, 1.54). This association was found to be primarily associated with residency outside of the largest metropolitan region of the province.

Conclusion
The likelihood of receiving a FP home visit during the end-of-life is associated with neighbourhood income particularly among patients living outside of a major metropolitan region.
Maps of the Sri Lanka malaria situation preceding the tsunami and key aspects to be considered in the emergency phase and beyond
Authors: Briët Olivier JT , Galappaththy Gawrie NL , Konradsen Flemming , Amerasinghe Priyanie H , Amerasinghe Felix P 
Published: January 2005

Abstract

Background
Following the tsunami, a detailed overview of the area specific transmission levels is essential in assessing the risk of malaria in Sri Lanka. Recent information on vector insecticide resistance, parasite drug resistance, and insights into the national policy for malaria diagnosis and treatment are important in assisting national and international agencies in their control efforts.

Methods
Monthly records over the period January 1995 – October 2004 of confirmed malaria cases were used to perform an analysis of malaria distribution at district spatial resolution. Also, a focused review of published reports and routinely collected information was performed.

Results
The incidence of malaria was only 1 case per thousand population in the 10 months leading up to the disaster, in the districts with the highest transmission.

Conclusion
Although relocated people may be more exposed to mosquito bites, and their capacity to handle diseases affected, the environmental changes caused by the tsunami are unlikely to enhance breeding of the principal vector, and, given the present low parasite reservoir, the likelihood of a malaria outbreak is low. However, close monitoring of the situation is necessary, especially as December – February is normally the peak transmission season. Despite some losses, the Sri Lanka public health system is capable of dealing with the possible threat of a malaria outbreak after the tsunami. The influx of foreign medical assistance, drugs, and insecticides may interfere with malaria surveillance, and the long term malaria control strategy of Sri Lanka, if not in accordance with government policy.
Carbenoxolone Induces Oxidative Stress in Liver Mitochondria, Which Is Responsible for Transition Pore Opening
Authors: Salvi Mauro , Fiore Cristina , Battaglia Valentina , Palermo Mario , Armanini Decio , Toninello Antonio 
Published: January 2005

AbstractCarbenoxolone (Cbx), a derivative of glycyrrhetinic acid, which has been found to affect mineralocorticoid and glucocorticoid receptors, induces swelling and membrane potential collapse when added to Ca2+-loaded liver mitochondria at 10 μm concentrations.These effects are strictly correlated with hydrogen peroxide generation, increase in oxygen uptake, and sulfhydryl and pyridine nucleotide oxidation. Cyclosporin A, bongkrekic acid, and N-ethylmaleimide completely abolish all the above-described effects, suggesting that Cbx can be considered an inducer of mitochondrial permeability transition by means of oxidative stress. Cbx can also trigger the apoptotic pathway because the above events are also correlated with the loss of cytochrome c. These effects are probably related to the conjugated carbonyl oxygen in C-11, which produces reactive oxygen species by interacting with the mitochondrial respiratory chain, mainly at the level of complex I but, most likely, also with complex III. The oxidative stress induced by Cbx, which is responsible for pore opening, excludes that this is related to a genomic effect of the compound.
Nestin-Immunoreactive Cells in Rat Pituitary Are neither Hormonal nor Typical Folliculo-Stellate Cells
Authors: Krylyshkina Olga , Chen Jianghai , Mebis Liese , Denef Carl , Vankelecom Hugo 
Published: January 2005

Abstract
Nestin is an intermediate filament protein that has originally been identified as a marker of neuroepithelial stem/progenitor cells. The present study explored whether nestin immunoreactivity (nestin-ir) is present in the rat pituitary and in which cell type(s). Nestin-ir was observed in scattered cells in the anterior, intermediate, and neural lobes. Nestin-ir cells were predominantly of stellate shape and were more numerous in immature than in adult animals. Nestin-ir did not colocalize with any pituitary hormone, and did not colocalize or only very sporadically with the folliculo-stellate cell marker S100. In the intermediate lobe, nestin-ir cells contained glial fibrillary acidic protein in an age-dependent manner. Nestin-ir cells were closely associated with endothelial and fibronectin-ir cells, but did mostly not coincide. Nestin-ir was not found in α-smooth muscle actin-ir myofibroblasts or in microglial cells. Regardless of age, nestin-ir was detected in some unidentifiable cells that border the pituitary cleft. Nestin-ir remained present in pituitary cultured as three-dimensional aggregates. Treatment with basic fibroblast growth factor or leukemia inhibitory factor increased the number of nestin-ir cells. Starting from anterior lobe cell monolayer cultures, nestin-ir cells could be selected and propagated to a virtually pure population. These nestin-ir cells displayed remarkable motility and proliferative activity, and did not express hormones, glial fibrillary acidic protein, or S100, but contained vimentin-, fibronectin-, and α-smooth muscle actin-ir. In conclusion, nestin-ir is present in the pituitary in cells that are neither hormonal nor typical folliculo-stellate. The expression pattern depends on age and lobe examined. Pericapillar localization suggests a pericyte phenotype for some of them. Whether the heterogeneous nestin-ir population also contains pituitary progenitor cells remains to be explored.
Adrenomedullin Stimulates Nitric Oxide Release from SK-N-SH Human Neuroblastoma Cells by Modulating Intracellular Calcium Mobilization
Authors: Xu Yong , Krukoff Teresa L. 
Published: January 2005

Abstract
We used SK-N-SH human neuroblastoma cells to test the hypothesis that adrenomedullin (ADM), a multifunctional neuropeptide, stimulates nitric oxide (NO) release by modulating intracellular free calcium concentration ([Ca2+]i) in neuron-like cells. We used a nitrite assay to demonstrate that ADM (10 pm to 100 nm) stimulated NO release from the cells, with a maximal response observed with 1 nm at 30 min. This response was blocked by 1 nm ADM22–52, an ADM receptor antagonist or 2 μm vinyl-l-NIO, a neuronal NO synthase inhibitor. In addition, 5 μm 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester, an intracellular calcium chelator, eliminated the ADM-induced NO release. Similar results were observed when the cells were incubated in calcium-free medium or when l-type calcium channels were inhibited with 5 μm nifedipine or 10 μm nitrendipine. Depletion of calcium stores in the endoplasmic reticulum (ER) with 1 μm cyclopiazonic acid or 150 nm thapsigargin, or inhibition of ryanodine-sensitive receptors in the ER with 10 μm ryanodine attenuated the ADM-induced NO release. NO responses to ADM were mimicked by 1 mm dibutyryl cAMP, a cAMP analog, and were abrogated by 5 μm H-89, a protein kinase A inhibitor. Furthermore, Fluo-4 fluorescence-activated cell sorter analysis showed that ADM (1 nm) significantly increased [Ca2+]i at 30 min. This response was blocked by nifedipine (5 μm) or H-89 (5 μm) and was reduced by ryanodine (10 μm). These results suggest that ADM stimulates calcium influx through l-type calcium channels and ryanodine-sensitive calcium release from the ER, probably via cAMP-protein kinase A-dependent mechanisms. These elevations in [Ca2+]i cause activation of neuronal NO synthase and NO release.
A Polymorphism in the 3′ Untranslated Region of the Gene for Tumor Necrosis Factor Receptor 2 Modulates Reporter Gene Expression
Authors: Puga Irene , Lainez Begoña , Fernández-Real José Manuel , Buxadé Maria , Broch Montserrat , Vendrell Joan , Espel Enric 
Published: January 2005

AbstractThe gene encoding the human TNFα receptor (TNFR) 2 contains polymorphisms in the 3′ untranslated region (UTR). Previous studies have shown that some variant alleles in this region are associated with obesity and insulin resistance. However, the effect of these polymorphisms on the expression of TNFR2 has not been studied to date. To examine the role played by different haplotypes in the control of TNFR2 expression (haplotypes A1-A5, referring to nucleotides 1663 G/A, 1668 T/G, and 1690 T/C), we introduced these sequences into the 3′-UTR of a heterologous reporter gene and expressed the corresponding constructs in a human T-cell line. We demonstrate that a 485-nt fragment of the TNFR2 3′-UTR that contains a U-rich region decreases reporter expression and that haplotypes A1-A4 exert a stronger effect than A5. Furthermore, time-course assays of mRNA stability using actinomycin D revealed that haplotypes A1-A4 destabilize the mRNA. The proximal TNFR2 3′-UTR, independently of haplotype differences, responded to T-cell activation by increasing mRNA decay. Electromobility shift analysis demonstrated that protein(s) found in T-cell extracts bind to the 485-nt fragment. We suggest that an increased rate of TNFR2 mRNA decay protects cells from unrestrained TNFα effects and that this protection is weakened in A5 subjects. These findings may explain the association of this haplotype with obesity and increased leptin levels.
Apelin, a Newly Identified Adipokine Up-Regulated by Insulin and Obesity
Authors: Boucher Jérémie , Masri Bernard , Daviaud Danièle , Gesta Stéphane , Guigné Charlotte , Mazzucotelli Anne , Castan-Laurell Isabelle , Tack Ivan , Knibiehler Bernard , Carpéné Christian , Audigier Yves , Saulnier-Blache Jean-Sébastien , Valet Philippe 
Published: January 2005

Abstract
The results presented herein demonstrate that apelin is expressed and secreted by both human and mouse adipocytes. Apelin mRNA levels in isolated adipocytes are close to other cell types present in white adipose tissue or other organs known to express apelin such as kidney, heart, and to a lesser extent brown adipose tissue. Apelin expression is increased during adipocyte differentiation stage. A comparison of four different models of obesity in mice showed a large increase in both apelin expression in fat cells and apelin plasma levels in all the hyperinsulinemia-associated obesities and clearly demonstrated that obesity or high-fat feeding are not the main determinants of the rise of apelin expression. The lack of insulin in streptozotocin-treated mice is associated with a decreased expression of apelin in adipocytes. Furthermore, apelin expression in fat cells is strongly inhibited by fasting and recovered after refeeding, in a similar way to insulin. A direct regulation of apelin expression by insulin is observed in both human and mouse adipocytes and clearly associated with the stimulation of phosphatidylinositol 3-kinase, protein kinase C, and MAPK. These data provide evidence that insulin exerts a direct control on apelin gene expression in adipocytes. In obese patients, both plasma apelin and insulin levels were significantly higher, suggesting that the regulation of apelin by insulin could influence blood concentrations of apelin. The present work identifies apelin as a novel adipocyte endocrine secretion and focuses on its potential link with obesity-associated variations of insulin sensitivity status.
Adenosine 5′-Monophosphate-Activated Protein Kinase and p38 Mitogen-Activated Protein Kinase Participate in the Stimulation of Glucose Uptake by Dinitrophenol in Adult Cardiomyocytes
Authors: Pelletier Amélie , Joly Érik , Prentki Marc , Coderre Lise 
Published: January 2005

AbstractDuring metabolic stress, such as ischemia or hypoxia, glucose becomes the principal energy source for the heart. It has been shown that increased cardiac glucose uptake during metabolic stress has a protective effect on cell survival and heart function. Despite its physiological importance, only limited data are available on the molecular mechanisms regulating glucose uptake under these conditions. We used 2,4-dinitrophenol (DNP), an uncoupler of oxidative phosphorylation, as a model to mimic hypoxia and gain insight into the signaling pathway underlying metabolic stress-induced glucose uptake in primary cultures of rat adult cardiomyocytes. The results demonstrate that 0.1 mm DNP induces 2.2- and 9-fold increases in AMP-activated protein kinase (AMPK) and p38 MAPK phosphorylation, respectively. This is associated with a 2.3-fold increase in glucose uptake in these cells. To further delineate the role of AMPK in the regulation of glucose uptake, we used two complementary approaches: pharmacological inhibition of the enzyme with adenine 9-β-D arabinofuranoside and adenoviral infection with a dominant-negative AMPK (DN-AMPK) mutant. Our results show that overexpression of DN-AMPK completely suppressed DNP-mediated phosphorylation of acetyl coenzyme A carboxylase, a downstream target of AMPK. Inhibition of AMPK with either 9-β-D arabinofuranoside or DN-AMPK also abolished DNP-mediated p38 MAPK phosphorylation. Importantly, AMPK inhibition only partially decreased DNP-stimulated glucose uptake in cardiomyocytes. Inhibition of p38 MAPK with the pharmacological agent PD169316 also partially reduced (70%) glucose uptake in response to DNP. In conclusion, our results indicate that p38 MAPK acts downstream of AMPK in cardiomyocytes and that activation of the AMPK/p38 MAPK signaling cascade is essential for maximal stimulation of glucose uptake in response to DNP in adult cardiomyocytes.
Genomic Regions that Mediate Placental Cell-Specific and Developmental Regulation of Human Cyp19 (Aromatase) Gene Expression in Transgenic Mice
Authors: Kamat Amrita , Smith Margaret E. , Shelton John M. , Richardson James A. , Mendelson Carole R. 
Published: January 2005

AbstractThe human aromatase (hCYP19) gene is controlled by tissue-specific promoters that lie upstream of tissue-specific first exons. Placenta-specific exon I.1 lies approximately 100,000 bp upstream of exon II. Previously, we observed that genomic sequences within 501 bp upstream of exon I.1 mediate placenta-specific expression. In the present study, transgenic mice were created carrying hCYP19I.1−246:hGH/hGX, hCYP19I.1−201:hGH, and hCYP19I.1−125:hGH fusion genes to further delineate 5′-flanking sequences within 501 bp of exon I.1 that are required to mediate placenta-specific hCYP19 gene expression. As little as 246 bp of hCYP19 exon I.1 5′-flanking sequence was sufficient to direct placenta-specific expression in transgenic mice. By contrast, transgenes containing 201 or 125 bp of exon I.1 5′-flanking DNA were not expressed in mouse placenta. Furthermore, hCYP19I.1−246:hGX transgene expression was developmentally regulated; expression was observed as early as embryonic d 7.5 (E7.5) in several cells of the trophoblast ectoderm, on E8.5 in some trophoblast giant cells, and by E9.5 in giant cells and the labyrinthine layer. By contrast, expression of the hCYP19I.1−501:hGH transgene was first observed on E10.5 and was restricted to the labyrinthine layer, which is most analogous to the human syncytiotrophoblast. This suggests the presence of regulatory elements between −501 and −246 bp that may bind inhibitory transcription factors expressed in giant cells. These findings from transgenic experiments together with deletion mapping studies using transfected human placental cells indicate that the concerted interaction of strong placenta-specific enhancers and silencers within this 501-bp region mediate labyrinthine and syncytiotrophoblast-specific CYP19 gene expression.
The Differential Binding Affinities of the Luteinizing Hormone (LH)/Choriogonadotropin Receptor for LH and Choriogonadotropin Are Dictated by Different Extracellular Domain Residues
Authors: Galet Colette , Ascoli Mario 
Published: January 2005

Abstract
The high degree of amino acid sequence homology and the divergent ligand binding affinities of the rat (r) and human (h) LH receptors (LHRs) allowed us to identify amino acid residues of their extracellular domain that are responsible for the different binding affinities of bovine (b) and hLH, and human choriogonadotropin (hCG) to the hLHR and rLHR. Because of the proposed importance of the β-sheets of the leucine-rich repeats (LRRs) of the extracellular domain of the LHR on hormone binding, we examined 10 divergent residues present in these regions by analyzing two complementary sets of mutants in which hLHR residues were substituted with the corresponding rLHR residues and vice versa. These experiments resulted in the identification of a single residue (a Ile or Ser in the C-terminal end of LRR2 of the hLHR or rLHR, respectively) that is important for hLH binding affinity. Surprisingly, however, this residue does not affect hCG or for bLH binding affinity. In fact, the results obtained with bLH and hCG show that several of the divergent residues in the β-sheets of LRR1–9 affect bLH binding affinity, but none of them affect hCG binding affinity. Importantly, our results also emphasize the involvement of residues outside of the β-sheets of the LRRs of the LHR in ligand binding affinity. This finding has to be considered in future models of the interaction of LH/CG with the LHR.