bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of polyoxymethylene plastic (POM) as a component of a tissue engineering bioreactor
Authors: Penick Kitsie J. , Solchaga Luis A. , Berilla Jim A. , Welter Jean F. 
Published: July 2005

AbstractPolyoxymethylene (POM, acetal homopolymer, polyacetal), commercialized as Delrin® by DuPont, is an engineering resin with mechanical properties that make it useful for the prototyping and manufacture of laboratory apparatus. These properties include excellent, “metal‐like,” machining characteristics and dimensional stability, as well as thermal stability, which allows steam sterilization. Historically, POM has been used widely, including as a surgical implant material. For these reasons, we have used this plastic as a media‐wetted component in a tissue‐engineering bioreactor, with good results. However, a study by LaIuppa et al.5 suggested that POM is unsuitable for use in a cell culture environment (LaIuppa et al. J Biomed Mater Res 1997;36:347–359). POM is based on the polymerization of formaldehyde, and, in addition, contains stabilizers and/or fillers. All of these could potentially be released into the medium, e.g., as formaldehyde or other thermal breakdown products, especially upon repeated autoclaving. The cited report thus appeared plausible, although contrary to our observations. In this study, we specifically assessed whether media conditioned by long‐term exposure to machined white POM had a negative effect on the proliferation and chondrogenic differentiation of human mesenchymal stem cells (MSCs). We selected this cell system, as cartilage tissue engineering is the primary application of our bioreactor system. The POM samples were steam‐autoclaved 1 to 20 times, to assess the possibility of any toxic thermal breakdown product release into the media. We found that MSCs did not attach directly to machined POM. Because cells that escape from the tissue construct cannot colonize the reactor and compete for nutrients, this is a desirable characteristic of a material used in a tissue‐engineering bioreactor. Furthermore, the use of POM‐conditioned media had no detectable impact on the proliferation rate of MSCs measured over a one‐week period; nor was any effect on chondrogenic differentiation observed at up to 3 weeks in culture. In summary, the use of POM as a culture medium‐wetted component appears to be innocuous, at least for human MSCs. The contrast of these findings to those of LaIuppa et al.5 may reflect a cell‐type specific sensitivity, or may be due to different handling of the material. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
A role for Runx2 in normal mammary gland and breast cancer bone metastasis
Authors: Shore Paul 
Published: July 2005

AbstractThe transcription factor Runx2 is essential for the formation of the skeleton. It has therefore primarily been considered as a specific regulator of bone genes. However, mice containing a LacZ insertion at the Runx2 locus also revealed expression in the nascent mammary epithelium. Reports of Runx2 expression in breast cancer cell lines, combined with the fact that breast cancers preferentially metastasise to bone, have also hinted at a potential role for Runx2 in the formation of bone metastasese. These initial observations have prompted further analysis of Runx2 function in mammary epithelial cells and recent findings have demonstrated that Runx2 does indeed contribute to the ability of metastatic breast cancer cell lines to form osteolytic bone lesions. In addition, evidence is accumulating that Runx2 has a role in the regulation of normal mammary gland gene expression and recent data demonstrate that it regulates transcription of the mammary gland‐specific gene, β‐casein. In this article I discuss recent advances that link Runx2 with normal mammary epithelial cell function and the development of bone metastasese in breast cancer. © 2005 Wiley‐Liss, Inc.
Mass spectrometric studies on brain metabolism, using stable isotopes
Authors: Ando Susumu , Tanaka Yasukazu 
Published: July 2005

AbstractIn fields related to biomedicine, mass spectrometry has been applied to metabolism research and chemical structural analysis. The introduction of stable isotopes has advanced research related to in vivo metabolism. Stable‐isotope labeling combined with mass spectrometry appears to be a superior method for the metabolism studies, because it compensates for the shortcomings of conventional techniques that use radioisotopes. Biomolecules labeled with stable isotopes have provided solid evidence of their metabolic pathways. Labeled large molecules, however, cannot homogeneously mix in vivo with the corresponding endogenous pools. To overcome that problem, small tracers labeled with stable isotopes have been applied to in vivo studies because they can diffuse and attain a homogeneous distribution throughout the inter‐ and intracellular spaces. In particular, D2O‐labeling methods have been used for studies of the metabolism in different organs, including the brain, which is isolated from other extraneural organs by the blood–brain barrier (BBB). Cellular components, such as lipids, carbohydrates, proteins, and DNA, can be endogenously and concurrently labeled with deuterium, and their metabolic fluxes examined by mass spectrometry. Application of the D2O‐labeling method to the measurements of lipid metabolism and membrane turnover in the brain is described, and the potential advantages of this method are discussed in this review. This methodology also appears to have the potential to be applied to dynamic and functional metabolomics. © 2005 Wiley Periodicals, Inc., Mass Spec Rev 24:865–886, 2005
Enhancement of the positive secondary ion yield during low‐energy, dual‐beam depth profiling of polytetrafluoroethylene with 1‐keV Cs+
Authors: Francis J. T. , McIntyre N. S. 
Published: July 2005

AbstractThis work documents the behaviour of the positive secondary ion yield of bulk polytetrafluoroethylene (PTFE) under dual‐beam depth profiling conditions employing 1 keV Ar+, Cs+ and SF5+. A unique chemical interaction is observed in the form of a dramatic enhancement of the positive secondary ion yield when PTFE is dual‐beam profiled with 1 keV Cs+. The distinct absence of such an enhancement is noted for comparison on two non‐fluorinated polymers, polyethylene terephthalate (PET) and polydimethylsiloxane (PDMS). The bulk PTFE was probed using 15‐keV, 69Ga+ primary ions in dual beam mode under static conditions; 1‐keV Ar+ (a non‐reactive, light, noble element), Cs+ (a heavier metallic ion known to form clusters) and SF5+ (a polyatomic species) served as the sputter ion species. The total accumulated primary ion dose was of the order of 1015 ions/cm2, which is well beyond the static limit. The enhancement of the positive secondary yield obtained when profiling with 1‐keV Cs+ far exceeds that obtained when SF5+ is employed. An explanation of this apparent reactive ion effect in PTFE is offered in terms of polarisation of CF bonds by Cs+ in the vicinity of the implantation site thereby predisposing them to facile scission. The formation of peculiar, periodic CsxFy+ (where y = x − 1) and CsxCyFz+ clusters that can extend to masses approaching 2000 amu are also observed. Such species may serve as useful fingerprints for fluorocarbons that can be initiated via pre‐dosing a sample with low‐energy Cs+ prior to static 15‐keV Ga+ analysis. Copyright © 2005 John Wiley & Sons, Ltd.
Wildfire effects on microbial biomass and diversity in pine forests at three topographic positions
Authors: Mabuhay J. A. , Isagi Y. , Nakagoshi N. 
Published: July 2005

AbstractThe aim of this study was to determine microbial biomass carbon and diversity at three topographic positions (ridge, middle slope and valley bottom) at varying periods after the occurrence of wildfire. The purpose of this study was to enhance knowledge on the microbiological status of post‐fire sites for a better estimate of the success of their restoration. Results showed that the biomass carbon and microbial diversity were affected by fire: the averages of the burnt plots were <50% of those of the unburnt plots. In addition, the biomass carbon at the sites studied 3 years after and 25 years after fire, and 5 months after and 9 years after fire, were not significantly different from each other. On the other hand, the site studied 5 months after fire showed the highest microbial diversity, followed by the ones studied 3, 25, 9 and 6 years after fire. In terms of topographic position, the ridge was shown to be the most affected by fire. These results show that fire can adversely affect the microbial biomass carbon and microbial diversity of the soil, the recovery of which may take a long time.
Pain among women: Associations with socio‐economic and work conditions
Authors: Jablonska Beata , Soares Joaquim J.F. , Sundin Örjan 
Published: July 2005

AbstractWe examined pain prevalence (general/body sites) and its characteristics/consequences among a randomised sample of women from the general population between 18 and 64 years (n= 3616). We also scrutinised associations between pain and various factors (e.g. socio‐economic) by means of multivariate logistic/linear regression analyses. The women completed a questionnaire assessing various areas (e.g. pain). The design was cross‐sectional and data were collected during 8 consecutive weeks. Sixty‐three per cent of women reported pain during the last 3 months, of which 65% during more than 3 months. The multivariate analyses revealed associations between various socio‐economic factors (e.g. financial strain) and pain in general/all studied body sites. In addition, psychosocial work conditions (i.e. work strain and social support) were significantly related to pain. Moreover, the multivariate analyses conducted among women with pain indicated relationships between socio‐economic/psychosocial work conditions, and pain characteristics (e.g. intensity) and consequences (i.e. disability). A large number of women from the general population suffer from pain, in particularly prolonged pain. Women in a deprived socio‐economic situation not only run a higher pain risk, but also experience their pain as more severe/disabling than their more privileged counterparts. Improvements of, for example, the socio‐economic status among women living in deprived social and material circumstances, along with improved working environment may be crucial to reduce women's pain problems.
Cell and tissue responses to electric shocks
Authors: Ashihara Takashi , Trayanova Natalia A. 
Published: July 2005

Abstract

Aim
Existing models of myocardial membrane kinetics have not been able to reproduce the experimentally-observed negative bias in the asymmetry of transmembrane potential changes (ΔVm) induced by strong electric shocks. The goals of this study are (1) to demonstrate that this negative bias could be reproduced by the addition, to the membrane model, of electroporation and an outward current, Ia, part of the K+ flow through the L-type Ca2+-channel, and (2) to determine how such modifications in the membrane model affect shock-induced break excitation in a 2D preparation.

Methods and results
We conducted simulations of shocks in bidomain fibres and sheets with membrane dynamics represented by the Luo–Rudy dynamic model (LRd'2000), to which electroporation (LRd+EP model) and the outward current, Ia, activated upon strong shock-induced depolarization (aLRd model) was added. Assuming Ia is a part of K+ flow through the L-type Ca2+-channel enabled us to reproduce both the experimentally observed rectangularly-shaped positive ΔVm and the value of near 2 of the negative-to-positive ΔVm ratio. In the sheet, Ia not only contributed to the negative bias in ΔVm asymmetry at sites polarized by physical and virtual electrodes, but also restricted positive ΔVm. Electroporation, in its turn, was responsible for the decrease in cathode-break excitation threshold in the aLRd sheet, compared with the other two cases, as well as for the occurrence of the excitation after the shock-end rather than during the shock.

Conclusions
The incorporation of electroporation and Ia in a membrane model ensures match between simulation results and experimental data. The use of the aLRd model results in a lower threshold for shock-induced break excitation.
Additive neuroprotective effects of creatine and cyclooxygenase 2 inhibitors in a transgenic mouse model of amyotrophic lateral sclerosis
Authors: Klivenyi Peter , Kiaei Mahmoud , Gardian Gabrielle , Calingasan Noel Y. , Beal M. Flint 
Published: July 2005

AbstractThere is substantial evidence implicating both inflammation and mitochondrial dysfunction in amyotrophic lateral sclerosis (ALS) pathogenesis. We investigated the therapeutic effects of cyclooxygenase 2 (COX‐2) inhibitors both alone and in combination with creatine in the G93A transgenic mouse model of ALS. Oral administration of either celecoxib or rofecoxib significantly improved motor performance, attenuated weight loss and extended survival. The administration of COX‐2 inhibitors significantly reduced prostaglandin E2 levels at 110 days of age. The combination of creatine with COX‐2 inhibitors produced additive neuroprotective effects and extended survival by approximately 30%. The COX‐2 inhibitors significantly protected against depletion of anterior horn motor neurons and creatine with COX‐2 inhibitors showed greater protection than COX‐2 inhibitors alone. These results suggest that combinations of therapies targeting different disease mechanisms may be a useful strategy in the treatment of ALS.
Celiac Disease with Mild to Moderate Histologic Changes is a Common Cause of Chronic Diarrhea in Indian Children
Authors: Bhatnagar Shinjini , Gupta Sidhartha Datta , Mathur Meera , Phillips Alan D , Kumar Ramesh , Knutton Stuart , Unsworth Joe , Lock Bob , Natchu Uma C. M , Mukhopadhyaya Sanjay , Saini Savita , Bhan Maharaj K 
Published: July 2005

ABSTRACTObjectives:In developed countries, small bowel histology in coeliac disease is a spectrum, ranging from normal with increased intraepithelial lymphocytes to the classic flat mucosa. In developing countries, mild to moderate enteropathies in children with chronic diarrhea and growth failure are assumed to be caused by tropical sprue, persistent infections, or malnutrition with bacterial overgrowth. We report the prevalence and histology of coeliac disease in children with chronic diarrhea at a tertiary referral hospital in North India.Methods:Two hundred fifty‐nine children with symptoms indicating coeliac disease attended the All India Institute of Medical Sciences. Histology was graded after a modified Marsh classification. Serum immunoglobulin A anti‐endomysial antibodies (AEA) were assayed using indirect immunofluorescence. Subjects with abnormal histology and positive AEA were put on a gluten free diet (GFD). Coeliac disease was diagnosed on small intestinal biopsy changes and a clinical response to a GFD.Results:Severe enteropathies were present in 63 (24%) subjects, and 58 (92%) responded to a GFD. Sixty‐six (25%) had moderate histologic changes, 61 responding to a GFD. AEA was positive in 56 of 63 patients with severe and 65 of 66 with moderate enteropathies. Fifty‐seven children had mild enteropathies, and 19 of 20 with positive AEA responded clinically to a GFD.Conclusions:Coeliac disease is more common than previously believed. It presents a variable histology, and diagnoses may be missed or delayed if based only on severe enteropathies. Serology is a useful adjunct to diagnosis, and diagnostic criteria need to be developed appropriately for coeliac disease in developing countries despite limited facilities.
Green Sperm. Identification of Male Gamete Promoters in Arabidopsis
Authors: Engel Michele L. , Holmes-Davis Rachel , McCormick Sheila 
Published: July 2005

Abstract
Previously, in an effort to better understand the male contribution to fertilization, we completed a maize (Zea mays) sperm expressed sequence tag project. Here, we used this resource to identify promoters that would direct gene expression in sperm cells. We used reverse transcription-polymerase chain reaction to identify probable sperm-specific transcripts in maize and then identified their best sequence matches in the Arabidopsis (Arabidopsis thaliana) genome. We tested five different Arabidopsis promoters for cell specificity, using an enhanced green fluorescent protein reporter gene. In pollen, the AtGEX1 (At5g55490) promoter is active in the sperm cells and not in the progenitor generative cell or in the vegetative cell, but it is also active in ovules, roots, and guard cells. The AtGEX2 (At5g49150) promoter is active only in the sperm cells and in the progenitor generative cell, but not in the vegetative cell or in other tissues. A third promoter, AtVEX1 (At5g62580), was active in the vegetative cell during the later stages of pollen development; the other promoters tested (At1g66770 and At1g73350) did not function in pollen. Comparisons among GEX1 and GEX2 homologs from maize, rice (Oryza sativa), Arabidopsis, and poplar (Populus trichocarpa) revealed a core binding site for Dof transcription factors. The AtGEX1 and AtGEX2 promoters will be useful for manipulating gene expression in sperm cells, for localization and functional analyses of sperm proteins, and for imaging of sperm dynamics as they are transported in the pollen tube to the embryo sac.
Circadian Control of Messenger RNA Stability. Association with a Sequence-Specific Messenger RNA Decay Pathway
Authors: Lidder Preetmoninder , Gutiérrez Rodrigo A. , Salomé Patrice A. , McClung C. Robertson , Green Pamela J. 
Published: July 2005

Abstract
Transcriptional and posttranscriptional regulation are well-established mechanisms for circadian gene expression. Among the latter, differential messenger RNA (mRNA) stability has been hypothesized to control gene expression in response to the clock. However, direct proof that the rate of mRNA turnover can be regulated by the clock is lacking. Previous microarray expression data for unstable mRNAs in Arabidopsis (Arabidopsis thaliana) revealed that mRNA instability is associated with a group of genes controlled by the circadian clock. Here, we show that CCR-LIKE (CCL) and SENESCENCE ASSOCIATED GENE 1 transcripts are differentially regulated at the level of mRNA stability at different times of day. In addition, the changes in CCL mRNA stability continue under free-running conditions, indicating that it is controlled by the Arabidopsis circadian clock. Furthermore, we show that these mRNAs are targets of the mRNA degradation pathway mediated by the downstream (DST) instability determinant. Disruption of the DST-mediated decay pathway in the dst1 mutant leads to aberrant circadian mRNA oscillations that correlate with alterations of the half-life of CCL mRNA relative to parental plants in the morning and afternoon. That this is due to an effect on the circadian control is evidenced by mRNA decay experiments carried out in continuous light. Finally, we show that the defects exhibited by dst mutants are reflected by an impact on circadian regulation at the whole plant level. Together, these results demonstrate that regulation of mRNA stability is important for clock-controlled expression of specific genes in Arabidopsis. Moreover, these data uncover a connection between circadian rhythms and a sequence-specific mRNA decay pathway.
Cyclin-Dependent Kinase Inhibitors in Maize Endosperm and Their Potential Role in Endoreduplication
Authors: Coelho Cintia M. , Dante Ricardo A. , Sabelli Paolo A. , Sun Yuejin , Dilkes Brian P. , Gordon-Kamm William J. , Larkins Brian A. 
Published: July 2005

Abstract
Two maize (Zea mays) cyclin-dependent kinase (CDK) inhibitors, Zeama;KRP;1 and Zeama;KRP;2, were characterized and shown to be expressed in developing endosperm. Similar to the CDK inhibitors in Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum), the maize proteins contain a carboxy-terminal region related to the inhibitory domain of the mammalian Cip/Kip inhibitors. Zeama;KRP;1 is present in the endosperm between 7 and 21 d after pollination, a period that encompasses the onset of endoreduplication, while the Zeama;KRP;2 protein declines during this time. Nevertheless, Zeama;KRP;1 accounts for only part of the CDK inhibitory activity that peaks coincident with the endoreduplication phase of endosperm development. In vitro assays showed that Zeama;KRP;1 and Zeama;KRP;2 are able to inhibit endosperm Cdc2-related CKD activity that associates with p13Suc1. They were also shown to specifically inhibit cyclin A1;3- and cyclin D5;1-associated CDK activities, but not cyclin B1;3/CDK. Overexpression of Zeama;KRP;1 in maize embryonic calli that ectopically expressed the wheat dwarf virus RepA protein, which counteracts retinoblastoma-related protein function, led to an additional round of DNA replication without nuclear division.
The Potato Virus X TGBp2 Movement Protein Associates with Endoplasmic Reticulum-Derived Vesicles during Virus Infection
Authors: Ju Ho-Jong , Samuels Timmy D. , Wang Yuh-Shuh , Blancaflor Elison , Payton Mark , Mitra Ruchira , Krishnamurthy Konduru , Nelson Richard S. , Verchot-Lubicz Jeanmarie 
Published: July 2005

Abstract
The green fluorescent protein (GFP) gene was fused to the potato virus X (PVX) TGBp2 gene, inserted into either the PVX infectious clone or pRTL2 plasmids, and used to study protein subcellular targeting. In protoplasts and plants inoculated with PVX-GFP:TGBp2 or transfected with pRTL2-GFP:TGBp2, fluorescence was mainly in vesicles and the endoplasmic reticulum (ER). During late stages of virus infection, fluorescence became increasingly cytosolic and nuclear. Protoplasts transfected with PVX-GFP:TGBp2 or pRTL2-GFP:TGBp2 were treated with cycloheximide and the decline of GFP fluorescence was greater in virus-infected protoplasts than in pRTL2-GFP:TGBp2-transfected protoplasts. Thus, protein instability is enhanced in virus-infected protoplasts, which may account for the cytosolic and nuclear fluorescence during late stages of infection. Immunogold labeling and electron microscopy were used to further characterize the GFP:TGBp2-induced vesicles. Label was associated with the ER and vesicles, but not the Golgi apparatus. The TGBp2-induced vesicles appeared to be ER derived. For comparison, plasmids expressing GFP fused to TGBp3 were transfected to protoplasts, bombarded to tobacco leaves, and studied in transgenic leaves. The GFP:TGBp3 proteins were associated mainly with the ER and did not cause obvious changes in the endomembrane architecture, suggesting that the vesicles reported in GFP:TGBp2 studies were induced by the PVX TGBp2 protein. In double-labeling studies using confocal microscopy, fluorescence was associated with actin filaments, but not with Golgi vesicles. We propose a model in which reorganization of the ER and increased protein degradation is linked to plasmodesmata gating.