bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resistance to 1,25D‐induced differentiation in human acute myeloid leukemia HL60‐40AF cells is associated with reduced transcriptional activity and nuclear localization of the vitamin D receptor
Authors: Garay Edward , Donnelly Robert , Wang Xuening , Studzinski George P. 
Published: May 2007

AbstractThe anti‐neoplastic effects of 1,25‐dihydroxyvitamin D3 (1,25D) are well documented in numerous tumor cell systems and animal models of cancer. However, despite this pre‐clinical success, the clinical use of 1,25D is currently impeded by the dose‐limiting hypercalcemia, and the risk of development of resistance to 1,25D. In this study, we investigated the mechanism of resistance to 1,25D of HL60‐40AF cells, a model of drug‐resistant acute myeloid leukemia, derived from HL60 cells by cultivation in the presence of 1,25D. The data indicate that transcriptional activity of vitamin D receptor (VDR) in 40AF cells increases only briefly when the cells are treated with 1,25D, despite greater basal cellular levels of VDR protein in the resistant than in the 1,25D‐sensitive cells. Analysis of the 40AF VDR mRNA sequence indicated alterations in the 5′ untranslated region (UTR), but coding domain variations were not observed. When resistance to 1,25D‐induced differentiation of 40AF cells was reversed by a combination of 1,25D with potentiators of differentiation (plant derived antioxidants and a p38MAPK inhibitor), an increase in the level of nuclear VDR, as well as an increase in CYP24 mRNA expression was observed. These data suggest that decreased ability of 1,25D to induce VDR nuclear localization and the consequent VDR target gene transcription may be an important reason for the resistance of 40AF cells to 1,25D. Further, our data show that VDR localization and phosphorylation can be increased by combining 1,25D with potentiators of differentiation. Analysis of the mechanisms that underlie the reduction and potentiation of 1,25D‐mediated changes in VDR activity may lead to the identification of new cellular targets that enhance 1,25D‐induced monocytic differentiation. J. Cell. Physiol. 213:816–825. © 2007 Wiley‐Liss, Inc.
Antioxidants slow photoreceptor cell death in mouse models of retinitis pigmentosa
Authors: Komeima Keiichi , Rogers Brian S. , Campochiaro Peter A. 
Published: May 2007

AbstractRetinitis pigmentosa (RP) is a heterogeneous group of diseases in which one of a wide variety of mutations selectively causes rod photoreceptor cell death. After rods die, cone photoreceptors gradually die resulting in blindness. Antioxidants reduce cone cell death in rd1/rd1 mice indicating that cones die from oxidative damage in that model of rapidly progressive RP. In this study, we sought to determine if this observation could be generalized to models of other types of RP, rd10/rd10 mice, a model of more slowly progressive recessive RP, and Q344ter mice, a model of rapidly progressive dominant RP. Compared to appropriate vehicle‐treated controls, rd10/rd10 and Q344ter mice treated between P18 and P35 with a mixture of antioxidants previously found to be effective in rd1/rd1 mice showed significantly greater cone survival. Antioxidant‐treated rd10/rd10 mice showed preservation of cone function as shown by a significant increase in photopic ERG b‐wave amplitudes, and surprisingly showed temporary preservation of scotopic a‐wave amplitudes, prolonged rod survival, and slowed depletion of rhodopsin mRNA. These data suggest that oxidative damage contributes to cone cell death regardless of the disease causing mutation that leads to the demise of rods, and that in more slowly progressive rod degenerations, oxidative damage may also contribute to rod cell death. Protection from oxidative damage may be a broadly applicable treatment strategy in RP. J. Cell. Physiol. 213:809–815. © 2007 Wiley‐Liss, Inc.
Early replication and the apoptotic pathway
Authors: Cohen Stephanie M. , Cordeiro‐Stone Marila , Kaufman David G. 
Published: May 2007

AbstractIn higher eukaryotes there is a link between time of replication and transcription. It is generally accepted that genes that are actively transcribed are replicated in the first half of S phase while inactive genes replicate in the second half of S phase. We have recently reported that in normal human fibroblasts there are some functionally related genes that replicate at the same time in S phase. This had been previously reported for functionally related genes that are located in clusters, for example the α‐ and β‐globin complexes. We have shown, however, that this also occurs with some functionally related genes that are not organized in a cluster, but rather are distributed throughout the genome. For example, using GOstat analysis of data from our and other groups, we found an overrepresentation of genes involved in the apoptotic process among sequences that are replicated very early (approximately in the first hour of S phase) in both fibroblasts and lymphoblastoid cells. This finding leads us to question how and why the replication of genes in the apoptotic pathway is temporally organized in this manner. Here we discuss the possible explanations and implications of this observation. J. Cell. Physiol. 213: 434–439, 2007. © 2007 Wiley‐Liss, Inc.
Reducing ammonia emission from poultry manure composting via struvite formation
Authors: Zhang Wenxiu , Lau Anthony 
Published: May 2007

AbstractComposting can provide a viable alternative for poultry manure management in the Fraser Valley of British Columbia, Canada. However, it has a high potential for ammonia emission because of the high nitrogen content of poultry litter. The objective of this study was to reduce ammonia emission by precipitating ammonia into struvite before it can volatilize from the composting matrix. Nitrogen transformation occurs during composting, but struvite formation can help to conserve nitrogen, and does not allow a large amount of nitrogen to be released into the environment as ammonia or nitrate, because ammonium‐nitrogen becomes bound in struvite. It would also be possible to remove phosphorus from the manure. A laboratory‐scale experiment was conducted to examine the feasibility of struvite formation during poultry manure composting. Magnesium and phosphate salts were supplemented to create favorable conditions to form struvite. Results indicated that ammonia emission was reduced by 40% to 84%, while the nitrogen retention in compost was enhanced. The struvite formed in compost was confirmed by means of X‐ray diffraction; and scanning electron microscopy with energy dispersive X‐ray spectroscopy. Copyright © 2007 Society of Chemical Industry
Removal of diazinon by various advanced oxidation processes
Authors: Real Francisco J. , Benitez F. Javier , Acero Juan L. , Gonzalez Manuel 
Published: May 2007

AbstractDiazinon is a widely used organophosphorus insecticide that is an important pollutant in aquatic environments. The chemical removal of diazinon has been studied using UV radiation, ozone, Fenton's reagent, UV radiation plus hydrogen peroxide, ozone plus hydrogen peroxide and photo‐Fenton as oxidation processes. In the photodegradation process the observed quantum yields had values ranging between 2.42 × 10−2 and 6.36 × 10−2 mol E−1. Similarly, the ozonation reaction gave values for the rate constant ranging between 0.100 and 0.193 min−1. In the combined systems UV/H2O2 and O3/H2O2 the partial contributions to the global oxidation reaction of the direct and radical pathways were deduced. In the Fenton's reagent and photo‐Fenton systems, the mechanism of reaction has been partially discussed, and the predominant role of the radical pathway pointed out. Additionally, the rate constant for the reaction between diazinon and the hydroxyl radicals was determined, with the value 8.4 × 109 L mol−1 s−1 obtained. A comparison of the different oxidation systems tested under the same operating conditions revealed that UV radiation alone had a moderate oxidation efficiency, which is enhanced in the case of ozone, while the most efficient oxidant is the photo‐Fenton system. Copyright © 2007 Society of Chemical Industry
Electrochemical incineration of dyes using a boron‐doped diamond anode
Authors: Saez Cristina , Panizza Marco , Rodrigo Manuel A. , Cerisola Giacomo 
Published: May 2007

AbstractThe electrochemical oxidation of a synthetic wastewater containing the model dyes alizarin red (an anthraquinone) and Eriochrome black T (an azoic compound) has been studied on a boron‐doped diamond electrode (BDD) by both cyclic voltammetry and bulk electrolysis. The influence of the current density and dye concentration were investigated. The results obtained show that complete chemical oxygen demand (COD) and colour removal was obtained for both wastewaters. However, the nature of the pollutant, and specially the presence of functional groups (such as the azoic group) seems to strongly influence the performance and efficiency of the electrochemical process. The electro‐oxidation of alizarin red behaves as a mass‐transfer‐controlled process. In such a system, an increase in the current density leads to a decrease in the current efficiency. This can be explained by direct or hydroxyl radical mediated oxidation. The contrary tendency has been observed in Eriochrome black T electro‐oxidation. In this case, higher efficiencies were obtained working at high current densities. This may indicate that the mediated oxidation by electrogenerated reagent (such as peroxodisulphate) is the main oxidation mechanism involved in Eriochrome black T treatment. These compounds have a longer average lifetime than hydroxyl radicals, and it allows the reaction to be extended to the whole wastewater volume. This study has shown the suitability of the electrochemical process for completely removing the COD and total organic carbon and effectively decolourising of wastewaters containing synthetic dyes. Copyright © 2007 Society of Chemical Industry
Bladder ultrasound in the evaluation of the efficacy of dextranomer/hyaluronic acid injection for treatment of vesicoureteral reflux
Authors: Özcan Coşkun , Ergün Raziye , Özbek Süha Süreyya , Avanoğlu Ali , Ulman ⋖brahim 
Published: May 2007

AbstractPurpose.To determine whether sonographic examination of subureteral implants after endoscopic dextranomer/hyaluronic acid (DHA) injection would help to evaluate the efficacy of this method in the treatment of vesicoureteral reflux.Materials and Methods.Thirty‐six patients (49 ureters) who underwent endoscopic subureteral DHA injection were evaluated using voiding cystourethrography (VCUG) and bladder sonography for a mean duration of 2.1 years (range, 3 months to 6.5 years) after treatment. Patient records—including the results of VCUG, renal sonography, Dimercapto succinic acid (DMSA) scintigraphy, and periodic urinary analysis—were also reviewed to determine the outcome of treatment.Results.Reflux was corrected in 43/49 (88%) ureters (complete cure in 38, downgrading of reflux in 5). No change was noted in 6 (12%) ureters on VCUG. The reflux was found to be corrected in 19/22 (86%) ureters, with the implants clearly identifiable on sonography. However, reflux was documented in only 3/27 (11%) ureters, around which no implant was seen on sonography.Conclusion.The identification of the implant in the subureteral region by bladder sonography correlated with resolution of reflux in the early postinjection period. On the other hand, the majority of the implants disappeared on sonography in the long term despite correction of reflux. Therefore, we believe that the use of bladder sonography is not useful in the evaluation of patients in long‐term follow‐up. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
First evidence of the presence of chitin in skeletons of marine sponges. Part II. Glass sponges (Hexactinellida: Porifera)
Authors: Ehrlich Hermann , Krautter Manfred , Hanke Thomas , Simon Paul , Knieb Christiane , Heinemann Sascha , Worch Hartmut 
Published: May 2007

AbstractSponges (Porifera) are presently gaining increased scientific attention because of their secondary metabolites and specific skeleton structures. In contrast to demosponges, whose skeletons are formed from biopolymer spongin, glass sponges (hexactinellids) possess silica‐organic composites as the main natural material for their skeletal fibres. Chitin has a crystalline structure and it constitutes a network of organized fibres. This structure confers rigidity and resistance to organisms that contain it, including monocellular (yeast, amoeba, diatoms) and multicellular (higher fungi, arthropods, nematodes, molluscs) organisms. In contrast to different marine invertebrates whose exoskeletons are built of chitin, this polysaccharide has not been found previously as an endogenous biopolymer within glass sponges (Hexactinellida). We hypothesized that glass sponges, which are considered to be the most basal lineage of multicellular animals, must possess chitin. Here, we present a detailed study of the structural and physico‐chemical properties of skeletal fragments of the glass sponge Farrea occa. We show that these fibres have a layered design with specific compositional variations in the chitin/silica composite. We applied an effective approach for the demineralization of glass sponge skeletal formations based on an etching procedure using alkali solutions. The results show unambiguously that α‐chitin is an essential component of the skeletal structures of Hexactinellida. This is the first report of a silica–chitin's composite biomaterial found in nature. From this perspective, the view that silica–chitin scaffolds may be key templates for skeleton formation also in ancestral unicellular organisms, rather than silica–protein composites, emerges as a viable alternative hypothesis. J. Exp. Zool. (Mol. Dev. Evol.) 308B:473–483, 2007. © 2007 Wiley‐Liss, Inc.
Insights into spawning behavior and development of the european amphioxus (Branchiostoma lanceolatum)
Authors: Fuentes Michael , Benito Elia , Bertrand Stephanie , Paris Mathilde , Mignardot Aurelie , Godoy Laura , Jimenez‐Delgado Senda , Oliveri Diana , Candiani Simona , Hirsinger Estelle , D'Aniello Salvatore , Pascual‐Anaya Juan , Maeso Ignacio , Pestarino Mario , Vernier Philippe , Nicolas Jean‐François , Schubert Michael , Laudet Vincent , Geneviere Anne Marie , Albalat Ricard , Garcia Fernandez Jordi , Holland Nicholas D. , Escriva Hector 
Published: May 2007

AbstractThe cephalochordate amphioxus (Branchiostoma sp.) is an important animal model for studying the evolution of chordate developmental mechanisms. Obtaining amphioxus embryos is a key step for these studies. It has been shown that an increase of 3–4°C in water temperature triggers spawning of the European amphioxus (Branchiostoma lanceolatum) in captivity, however, very little is known about the natural spawning behavior of this species in the field. In this work, we have followed the spawning behavior of the European amphioxus during two spawning seasons (2004 and 2005), both in the field and in captivity. We show that animals in the field spawn approximately from mid‐May through early July, but depending on the year, they show different patterns of spawning. Thus, even if temperature has a critical role in the induction of the spawning in captivity, it is not the major factor in the field. Moreover, we report some improvements on the methodology for inducing spawning in captivity (e.g. in maintenance, light cycle control and induction of spawning in a laboratory without running sea water system). These studies have important implications for amphioxus animal husbandry and for improving laboratory techniques to develop amphioxus as an experimental animal model. J. Exp. Zool. (Mol. Dev. Evol.) 308B:484–493, 2007. © 2007 Wiley‐Liss, Inc.
Escaping the mouse trap: the selection of new Evo‐Devo model species
Authors: Milinkovitch Michel C. , Tzika Athanasia 
Published: May 2007

AbstractAmong the many, sometimes contradictory, criteria that have been used for promoting model species, the most prominent has probably been their relevance for understanding human biology. Recently however, the debate has partly shifted from the search for evolutionary conservation (medicine‐driven models) to a better understanding of the generative mechanisms underlying biological diversity (Evo‐Devo‐driven models). Integration of multiple disciplines, beyond developmental genetics and evolutionary molecular genetics, as well as of innovative technologies will help biologists to open the massive realm of living species to genome manipulation and phenotypic investigation. However, a consensual list of model species must still be reached for optimizing the interplay between in silico analyses and in vivo experiments, and we claim that the Evo‐Devo community should play a more energetic role in this endeavor. We discuss here a few criteria and limitations of major relevance to the choice of model species for Evo‐Devo studies, and promote the use of a pragmatic approach. Finally, given the difficulties related to manipulating and breeding model species, we suggest the development of Evo‐Devo virtual zoos maintaining breeding colonies of a selected set of species and from which eggs or staged embryos are available on order. J. Exp. Zool. (Mol. Dev. Evol.) 308B:337–346, 2007. © 2007 Wiley‐Liss, Inc.
A poverty‐focused evaluation of commodity tax options
Authors: Essama‐Nssah B. 
Published: May 2007

AbstractThe difficulties faced by many developing countries in raising revenue from direct taxes have forced them to rely heavily on indirect taxes to finance development interventions. The purpose of this paper is to illustrate how to identify socially desirable options for commodity taxation in the context of a poverty reduction strategy. Within the logic of social evaluation we assess tax options on the basis of value judgments underlying members of the additively separable class of poverty measures. The criterion hinges on both the pattern of consumption of each commodity and the price elasticity of the poverty measure used. An application of this methodology to data for Guinea shows that many components of food expenditure (particularly cereals, grains and roots) would be good candidates for exemption from VAT. Even though expenditure on health and education is distributed in favour of the non‐poor, their importance for human capital development argues for a program of targeted subsidies in a broader context of cost recovery. Copyright © 2007 John Wiley & Sons, Ltd.
Ribosomal distributions in axons of mammalian myelinated fibers
Authors: Kun Alejandra , Otero Leonardo , Sotelo‐Silveira José R. , Sotelo José R. 
Published: May 2007

AbstractThe distribution of ribosomes and polysomes in uninjured myelinated axons of rat sciatic nerve was analyzed. Ribosomes were identified by immunocytochemistry at the light and electron microscopic levels. A polyclonal antibody developed against ribosomes recognized both rRNA and ribosomal proteins. The distribution of the immunoreaction product was similar to that obtained with human anti‐ribosomal P protein. The immunoreaction product distributions were of two types in axons: 1) periodic localization in the cortical region of axoplasm that appeared as a compact structural aggregate, consistent with that described as a periaxoplasmic ribosomal plaques (PARP) domain (Koenig et al. [2000] J. Neurosci. 20:8390–8400), and 2) scattered small immuno‐reactive clusters of varying sizes (RNP) within the central core of the axon. The latter observation suggested the possibility that RNP‐like particles could be associated with the axonal transport system and in transit. Immunoreaction product was also associated with a novel structural inclusion, possibly multi‐vesicular in makeup that was located in the axon and at the myelin‐axon interface, and visible at the light and EM levels. The potential significance of this structural peculiarity is considered. © 2007 Wiley‐Liss, Inc.
Mechanisms of nitric oxide‐induced apoptosis in bovine chromaffin cells: Role of mitochondria and apoptotic proteins
Authors: Pérez‐Rodríguez Rocío , Fuentes María P. , Oliván Anna M. , Martínez‐Palacián Adoración , Roncero Cesáreo , González María P. , Oset‐Gasque María J. 
Published: May 2007

AbstractThe aim of this work was to establish the possible involvement of mitochondria in the apoptotic event triggered by nitric oxide (NO) in chromaffin cells. Using bovine chromaffin cells in primary culture and several NO donors (SNP, SNAP, and GSNO) at apoptotic concentrations (50 μM–1 mM), we have shown that NO induces a time‐dependent decrease in the mitochondrial transmembrane potential (ΔΨm), which correlates with the appearance of hypodiploid cells. Disruption in ΔΨmis followed by cytochrome c release to the cytosol, which in turn precedes caspase 3 activation. In this mechanism participates the Bcl‐2 protein family, because NO donors downregulate the expression of anti‐apoptotic members of the family such as Bcl‐2 and Bcl‐XL, and increase the expression of pro‐apoptotic members, Bax and Bcl‐Xs, inductors of cytochrome c release to cytosol. Different cell signaling pathways seem to regulate Bax induction and Bcl‐2 inhibition because decreased Bcl‐2 levels are detected later than enhanced Bax expression. The tumour suppressor protein p53 is also upregulated in a very early phase (30 min) of the NO‐induced apoptosis and may be responsible for the further induction of Bax expression. Finally, the translocation of NF‐κB to the nucleus seems to be another early event in NO‐induced apoptosis and it may be involved in the regulation of p53 expression. These results support strongly the participation of mitochondrial mechanisms in NO‐induced apoptosis in chromaffin cells and suggest that these cells may be good models for the investigation of molecular basis of neurodegeneration and neuroprotection. © 2007 Wiley‐Liss, Inc.
Flavoprotein autofluorescence imaging in the cerebellar cortex in vivo
Authors: Reinert Kenneth C. , Gao Wangcai , Chen Gang , Ebner Timothy J. 
Published: May 2007

AbstractAutofluorescence optical imaging is rapidly becoming a widely used tool for mapping activity in the central nervous system function in vivo and investigating the coupling among neurons, glia, and metabolism. This paper provides a brief review of autofluorescence and of our recent work using flavoprotein imaging in the cerebellar cortex. Stimulation of the parallel fibers evokes an intrinsic fluorescence signal that is tightly coupled to neuronal activation and primarily generated postsynaptically. The signal originates from mitochondrial flavoproteins. The signal is biphasic, with the initial increase in fluorescence (light phase) resulting from the oxidation of flavoproteins and the subsequent decrease (dark phase) from the reduction of flavoproteins. The light phase is primarily neuronal, and the dark phase is primarily glial. Exploiting the spatial properties of molecular layer inhibition in the cerebellar cortex, we show that flavoprotein autofluorescence can monitor both excitatory and inhibitory activity in the cerebellar cortex. Furthermore, flavoprotein autofluorescence has revealed that molecular layer inhibition is organized into parasagittal domains that differentially modulate the spatial pattern of cerebellar cortical activity. The reduction in flavoprotein autofluorescence occurring in the inhibitory bands most likely reflects a decrease in intracellular Ca2+ in the neurons inhibited by the molecular layer interneurons. Therefore, flavoprotein autofluorescence imaging is providing new insights into cerebellar cortical function and neurometabolic coupling. © 2007 Wiley‐Liss, Inc.