bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Experimental Design on Choice‐Based Conjoint Valuation Estimates
Authors: Lusk Jayson L. , Norwood F. Bailey 
Published: July 2005

AbstractIn this article, we investigate the effect of several commonly used experimental designs on willingness‐to‐pay in a Monte Carlo environment where true utility parameters are known. All experimental designs considered in this study generated unbiased valuation estimates. However, random designs or designs that explicitly incorporated attribute interactions generated more precise valuation estimates than main effects only designs. A key result of our analysis is that a large sample size can substitute for a poor experimental design. Overall, our results indicate that certain steps can be taken to achieve a manageably sized experimental design without sacrificing the credibility of welfare estimates.
Nuclear factor‐κB activation by reactive oxygen species mediates voltage‐gated K+ current enhancement by neurotoxic β‐amyloid peptides in nerve growth factor‐differentiated PC‐12 cells and hippocampal neurones
Authors: Pannaccione Anna , Secondo Agnese , Scorziello Antonella , Calì Gaetano , Taglialatela Maurizio , Annunziato Lucio 
Published: July 2005

AbstractIncreased activity of plasma membrane K+ channels, leading to decreased cytoplasmic K+ concentrations, occurs during neuronal cell death. In the present study, we showed that the neurotoxic β‐amyloid peptide Aβ25−35 caused a dose‐dependent (0.1–10 µm) and time‐dependent (> 12 h) enhancement of both inactivating and non‐inactivating components of voltage‐dependent K+ (VGK) currents in nerve growth factor‐differentiated rat phaeochromocytoma (PC‐12) cells and primary rat hippocampal neurones. Similar effects were exerted by Aβ1−42, but not by the non‐neurotoxic Aβ35−25 peptide. Aβ25−35 and Aβ1−42 caused an early (15–20 min) increase in intracellular Ca2+ concentration. This led to an increased production of reactive oxygen species (ROS), which peaked at 3 h and lasted for 24 h; ROS production seemed to trigger the VGK current increase as vitamin E (50 µm) blocked both the Aβ25−35‐ and Aβ1−42‐induced ROS increase and VGK current enhancement. Inhibition of protein synthesis (cycloheximide, 1 µg/mL) and transcription (actinomycin D, 50 ng/mL) blocked Aβ25−35‐induced VGK current enhancement, suggesting that this potentiation is mediated by transcriptional activation induced by ROS. Interestingly, the specific nuclear factor‐κB inhibitor SN‐50 (5 µm), but not its inactive analogue SN‐50M (5 µm), fully counteracted Aβ1−42‐ or Aβ25−35‐induced enhancement of VGK currents, providing evidence for a role of this family of transcription factors in regulating neuronal K+ channel function during exposure to Aβ.
Beta‐amyloid peptides stimulate endozepine biosynthesis in cultured rat astrocytes
Authors: Tokay Tursonjan , Masmoudi Olfa , Gandolfo Pierrick , Leprince Jérôme , Pelletier Georges , Vaudry Hubert , Tonon Marie‐Christine 
Published: July 2005

AbstractAccumulation of β‐amyloid peptide (Aβ), which is a landmark of Alzheimer's disease, may alter astrocyte functions before any visible symptoms of the disease occur. Here, we examined the effects of Aβ on biosynthesis and release of diazepam‐binding inhibitor (DBI), a polypeptide primarily expressed by astroglial cells in the CNS. Quantitative RT–PCR and specific radioimmunoassay demonstrated that aggregated Aβ25−35, at concentrations up to 10−4 m, induced a dose‐dependent increase in DBI mRNA expression and DBI‐related peptide release from cultured rat astrocytes. These effects were totally suppressed when aggregation of Aβ25−35 was prevented by Congo red. Measurement of the number of living cells revealed that Aβ25−35 induced a trophic rather than a toxic effect on astrocytes. Administration of cycloheximide blocked Aβ25−35‐induced increase of DBI gene expression and endozepine accumulation in astrocytes, indicating that protein synthesis is required for DBI gene expression. Altogether, the present data suggest that Aβ‐induced activation of endozepine biosynthesis and release may contribute to astrocyte proliferation associated with Alzheimer's disease.
Treatment with extracellular HSP70/HSC70 protein can reduce polyglutamine toxicity and aggregation
Authors: Novoselova Tatiana V. , Margulis Boris A. , Novoselov Sergey S. , Sapozhnikov Alexander M. , Van Der Spuy Jacqueline , Cheetham Michael E. , Guzhova Irina V. 
Published: July 2005

AbstractThe accumulation of insoluble protein aggregates is a feature of neurodegenerative disease. Overexpression of Heat Shock Protein 70 (HSP70) can protect cells with protein aggregates from apoptosis. Another trait of HSP70 is its ability to cross the plasma membrane. Therefore, we purified a preparation of HSP70/HSC70 from bovine muscle and used it in a model of Huntington's disease. Human neuroblastoma SK‐N‐SH cells were transfected with huntington exon 1 with short (25) or long (103) CAG trinucleotide repeats coupled to green flourescent protein (GFP). Cells transfected with the long polyCAG repeat had insoluble protein aggregates and died through apoptosis. Biotinylated HSP70/HSC70 incorporated into the culture medium appeared inside the cells within 3–6 h of incubation. This incorporation correlated with a reduction in apoptotic cells by 40–50%. Confocal microscopy revealed that labelled internalized HSP70/HSC70 co‐localized with the polyglutamine inclusions. The measurement of the number and size of inclusions showed that HSP70/HSC70 was able to reduce both these parameters. A filter trap assay and immunoblotting demonstrated that the introduction of HSP70/HSC70 also decreased protein aggregation. Together with earlier data on the effects of exogenously administered HSP70/HSC70 on cultured cells and on animals, these data show that preparations based on HSP70 may have some potential as therapies for a variety of neurodegenerative pathologies.
Dystroglycan and Kir4.1 coclustering in retinal Müller glia is regulated by laminin‐1 and requires the PDZ‐ligand domain of Kir4.1
Authors: Noël Geoffrey , Belda Marina , Guadagno Eric , Micoud Julien , Klöcker Nikolaj , Moukhles Hakima 
Published: July 2005

AbstractInwardly rectifying potassium (Kir) channels in Müller glia play a critical role in the spatial buffering of potassium ions that accumulate during retinal activity. To this end, Kir channels show a polarized subcellular distribution with the predominant channel subunit in Müller glia, Kir4.1, clustered in the endfeet of these cells at the inner limiting membrane. However, the molecular mechanisms underlying their distribution have yet to be identified. Here, we show that laminin, agrin and α‐dystroglycan (DG) codistribute with Kir4.1 at the inner limiting membrane in the retina and that laminin‐1 induces the clustering of α‐DG, syntrophin and Kir4.1 in Müller cell cultures. In addition, we found that α‐DG clusters were enriched for agrin and sought to investigate the role of agrin in their formation using recombinant C‐agrins. Both C‐agrin 4,8 and C‐agrin 0,0 failed to induce α‐DG clustering and neither of them potentiated the α‐DG clustering induced by laminin‐1. Finally, our data reveal that deletion of the PDZ‐ligand domain of Kir4.1 prevents their laminin‐induced clustering. These findings indicate that both laminin‐1 and α‐DG are involved in the distribution of Kir4.1 to specific Müller cell membrane domains and that this process occurs via a PDZ‐domain‐mediated interaction. Thus, in the basal lamina laminin is an essential regulator involved in clearing excess potassium released during neuronal activity, thereby contributing to the maintenance of normal synaptic transmission in the retina.
The POZ/BTB protein NAC1 interacts with two different histone deacetylases in neuronal‐like cultures
Authors: Korutla L. , Wang P. J. , Mackler S. A. 
Published: July 2005

AbstractNAC1 is a cocaine‐regulated POZ/BTB (Pox virus and Zinc finger/Bric‐a‐brac Tramtrack Broad complex) protein. NAC1 is increased by cocaine selectively in the nucleus accumbens, a CNS region important for drug addiction. NAC1's role in the cell, however, is not known. Each of the two NAC1 isoforms, sNAC1 (short NAC1) and lNAC1 (long NAC1), may serve as corepressors for other POZ/BTB proteins. This study investigated whether sNAC1 and lNAC1 demonstrated protein–protein interactions with other corepressors. Histone deacetylase (HDAC) inhibition reversed sNAC1 and lNAC1 repression of Gal4 luciferase, but only in neuronal‐like cultures. Because these inhibitors do not distinguish among histone deacetylases, two histone deacetylases were selected for further study. HDAC 3 and 4 both demonstrated protein–protein interactions with sNAC1 and lNAC1. This was shown using coimmunoprecipitations, glutathione‐S‐transferase (GST) pulldowns and mammalian two‐hybrids. Importantly, either the POZ domain or NAC1 without the POZ domain can bind these two HDACs. Other corepressors, specifically NCoR (nuclear receptor corepressor), SMRT (silencing mediator for retinoid and thyroid hormone receptor) and mSin3a, do not exhibit protein–protein interactions with sNAC1 and lNAC1. None showed protein–protein interactions in GST pulldowns or mammalian two‐hybrids. Taken together, the results of these experiments indicate sNAC1 and lNAC1 recruit histone deacetylases for transcriptional repression, further enhancing POZ/BTB protein mediated repression.
Antioxidant properties of minocycline: neuroprotection in an oxidative stress assay and direct radical‐scavenging activity
Authors: Kraus Richard L. , Pasieczny Rodger , Lariosa‐Willingham Karen , Turner Mary S. , Jiang Alice , Trauger John W. 
Published: July 2005

AbstractMinocycline is neuroprotective in animal models of a number of acute CNS injuries and neurodegenerative diseases. While anti‐inflammatory and anti‐apoptotic effects of minocycline have been characterized, the molecular basis for the neuroprotective effects of minocycline remains unclear. We report here that minocycline and a number of antioxidant compounds protect mixed neuronal cultures in an oxidative stress assay. To evaluate the role of minocycline's direct antioxidant properties in neuroprotection, we determined potencies for minocycline, other tetracycline antibiotics, and reference antioxidant compounds using a panel of in vitro radical scavenging assays. Data from in vitro rat brain homogenate lipid peroxidation and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assays show that minocycline, in contrast to tetracycline, is an effective antioxidant with radical scavenging potency similar to vitamin E. Our findings suggest that the direct antioxidant activity of minocycline may contribute to its neuroprotective effects in some cell‐based assays and animal models of neuronal injury.
Induction of tyrosine hydroxylase in the locus coeruleus of transgenic mice in response to stress or nicotine treatment: lack of activation of tyrosine hydroxylase promoter activity
Authors: Osterhout Cheryl A. , Sterling Carol R. , Chikaraishi Dona M. , Tank A. William 
Published: July 2005

AbstractProlonged stress or chronic nicotine administration leads to induction of tyrosine hydroxylase (TH) in adrenal medulla and locus coeruleus (LC) of the rat. In this study we use mice that express a transgene encoding 4.5 kb of TH gene 5′‐flanking region fused upstream of the reporter gene, human alkaline phosphatase (hAP) to test whether TH gene promoter activity is stimulated by immobilization stress, cold exposure or nicotine administration in adrenal medulla and LC. TH‐hAP transgene expression is increased in response to all three stimuli in the adrenal medulla. In contrast, TH‐hAP expression does not increase in response to either immobilization stress or nicotine administration in the LC and only a small induction of LC TH‐hAP mRNA is observed in response to cold exposure. TH mRNA is induced 2–3 fold and TH activity is increased significantly by all three stimuli in both the adrenal and LC. These results support the hypothesis that TH expression is induced by stress or nicotine treatment in both the adrenal medulla and LC of the mouse. The induction in the adrenal is dependent primarily on transcriptional mechanisms, whereas that in the LC is apparently dependent primarily on post‐transcriptional mechanisms.
Age‐associated changes in mRNA levels of Phox2, norepinephrine transporter and dopamine β‐hydroxylase in the locus coeruleus and adrenal glands of rats
Authors: Zhu Meng‐Yang , Wang Wei‐Ping , Iyo Abiye H. , Ordway Gregory A. , Kim Kwang‐Soo 
Published: July 2005

AbstractAge‐related changes in the gene expression of the transcription factors, Phox2a and 2b, and two marker proteins, norepinephrine transporter (NET) and dopamine β‐hydroxylase (DBH), of noradrenergic neurons were characterized in the locus coeruleus (LC) and adrenal glands using in situ hybridization. Analysis of changes was performed in rats that were 1–23 months of age. Compared to 1‐month‐old rats, there was a 62% increase of Phox2a messenger RNA (mRNA) in the LC of 3‐month‐old rats, and a decline of 37% in 23‐month‐old rats. In contrast, levels of Phox2b mRNA in the LC remained unchanged in 3‐month‐old rats, but declined to a 30% reduction in 23‐month‐old rats. Interestingly, mRNA levels of NET in the LC decreased with increasing age to a reduction of 29%, 30% and 43% in 3‐, 8‐ and 23‐month‐old rats, respectively. Similarly, DBH mRNA in the LC declined with increasing age to a 56% reduction in 23‐month‐old rats. mRNA levels of Phox2a, Phox2b, NET and DBH in the adrenal medulla of 23‐month‐old rats were significantly lower than those of 1‐month‐old rats. Semi‐quantitative reverse transcription assays of the same genes yielded data similar to in situ hybridization experiments, with β‐actin mRNA levels being unchanged across the ages. Taken together, these data reveal that reduced Phox2 mRNAs in the LC and adrenal medulla of aging rats are accompanied by a coincidental decline in mRNA levels of NET and DBH and suggest a possible relationship between Phox2 genes and the marker genes in noradrenergic neurons after birth.
Proteolytic degradation of glutamate decarboxylase mediates disinhibition of hippocampal CA3 pyramidal cells in cathepsin D‐deficient mice
Authors: Shimizu Tokiko , Hayashi Yoshinori , Yamasaki Ryo , Yamada Jun , Zhang Jian , Ukai Kiyoharu , Koike Masato , Mine Kazunori , Von Figura Kurt , Peters Christoph , Saftig Paul , Fukuda Takaichi , Uchiyama Yasuo , Nakanishi Hiroshi 
Published: July 2005

AbstractAlthough of clinical importance, little is known about the mechanism of seizure in neuronal ceroid lipofuscinosis (NCL). In the present study, we have attempted to elucidate the mechanism underlying the seizure of cathepsin D‐deficient (CD–/–) mice that show a novel type of lysosomal storage disease with a phenotype resembling late infantile NCL. In hippocampal slices prepared from CD–/– mice at post‐natal day (P)24, spontaneous burst discharges were recorded from CA3 pyramidal cells. At P24, the mean amplitude of IPSPs after stimulation of the mossy fibres was significantly smaller than that of wild‐type mice, which was substantiated by the decreased level of γ‐aminobutyric acid (GABA) contents in the hippocampus measured by high‐performance liquid chromatography (HPLC). At this stage, activated microglia were found to accumulate in the pyramidal cell layer of the hippocampal CA3 subfield of CD–/– mice. However, there was no significant change in the numerical density of GABAergic interneurons in the CA3 subfield of CD–/– mice at P24, estimated by counting the number of glutamate decarboxylase (GAD) 67‐immunoreactive somata. In the hippocampus and the cortex of CD–/– mice at P24, some GABAergic interneurons displayed extremely high somatic granular immunoreactivites for GAD67, suggesting the lysosomal accumulation of GAD67. GAD67 levels in axon terminals abutting on to perisomatic regions of hippocampal CA3 pyramidal cells was not significantly changed in CD–/– mice even at P24, whereas the total protein levels of GAD67 in both the hippocampus and the cortex of CD–/– mice after P24 were significantly decreased as a result of degradation. Furthermore, the recombinant human GAD65/67 was rapidly digested by the lysosomal fraction prepared from the whole brain of wild‐type and CD–/– mice. These observations strongly suggest that the reduction of GABA contents, presumably because of lysosomal degradation of GAD67 and lysosomal accumulation of its degraded forms, are responsible for the dysfunction of GABAergic interneurons in the hippocampal CA3 subfield of CD–/– mice.
Calorie restriction delays lipid oxidative damage in Drosophila melanogaster
Authors: Zheng Jianyu , Mutcherson Raye , Helfand Stephen L. 
Published: July 2005

SummaryThe oxidative stress hypothesis predicts that the accumulation of oxidative damage to a variety of macromolecules is the molecular trigger driving the process of aging. Although an inverse relationship between oxidative damage and lifespan has been established in several different species, the precise relationship between oxidative damage and aging is not fully understood. Drosophila melanogaster is a favored model organism for aging research. Environmental interventions such as ambient temperature and calorie restriction can alter adult lifespan to provide an excellent system to examine the relationship between oxidative damage, aging and lifespan. We have developed an enzyme‐linked immunosorbent assay (ELISA) using commercially available reagents for measuring 4‐hydroxy‐2‐nonenal (HNE) in proteins, a marker for oxidative damage to lipids, and present data in flies to show that HNE adducts accumulate in an age‐dependent manner. With immunohistology, we also find the primary site of HNE accumulation is the pericerebral fat body, where induction of dFOXO was recently shown to retard aging. When subjected to environmental interventions that shorten lifespan, such as elevated ambient temperature, the chronological accumulation of HNE adduct is accelerated. Conversely, interventions that extend lifespan, such as lower ambient temperature or low calorie diets, slow the accumulation of HNE adduct. These studies associate damage from lipid peroxidation with aging and lifespan in Drosophila and show that calorie restriction in flies, as in mammals, slows the accumulation of lipid related oxidative damage.
HIF‐1α cytoplasmic accumulation is associated with cell death in old rat cerebral cortex exposed to intermittent hypoxia
Authors: Rapino Cinzia , Bianchi Giuseppina , Di Giulio Camillo , Centurione Lucia , Cacchio Marisa , Antonucci Adriano , Cataldi Amelia 
Published: July 2005

SummaryIntermittent hypoxia, followed by reoxygenation, determines the production of reactive oxygen species (ROS), which may lead to accelerated aging and to the appearance of age‐related diseases. The rise in ROS levels might constitute a stress‐stimulus activating specific redox–sensitive signalling pathways, so inducing either damaging or protective functions. Here, we report that in old rat cerebral cortex exposed to hypoxia, the accumulation in the cytoplasm of hypoxic inducible factor 1α (HIF‐1α) – the master regulator of oxygen homeostasis – concomitant with p66Shc activation and reduced IkBα phosphorylation is associated with tissue apoptosis or necrosis. In young cerebral cortex, we hypothesize that the hypoxic damage may be reversible, based on our demonstration of elevated HIF‐1α levels, combined with a low level of IkBα phosphorylation, a decrease in IAP‐1 and a lack of major change in Bcl2 family proteins. These observations are associated with a low level of cell death induced by hypoxia, suggesting that HIF‐1α activation in cortical neurons may produce rescue proteins in response to intermittent hypoxia.
Caspase‐independent cytochrome c release is a sensitive measure of low‐level apoptosis in cell culture models
Authors: Goldstein Joshua C. , Rodier Francis , Garbe James C. , Stampfer Martha R. , Campisi Judith 
Published: July 2005

SummaryAge‐associated loss of tissue function and several chronic diseases may derive in part from the cumulative effects of subtle changes in the level of apoptotic cell death. Because apoptosis is rapid and undetectable once complete, small changes in its incidence are difficult to detect, even in well‐controlled cell cultures. We describe a new apoptosis assay that provides greater sensitivity than conventional assays because it measures the accumulation of apoptotic cells. Human and mouse fibroblasts and human mammary epithelial cells that initiated apoptosis were preserved for 3 days by inhibiting caspase activity using the chemical inhibitor Q‐VD‐OPH (QVD). Cells suspended in the process of apoptosis were scored by immunostaining for cytochrome c, which redistributed from mitochondria in healthy cells to the cytoplasm in dying cells. This caspase‐independent cytochrome c release (CICR) assay was more sensitive than several conventional assays when apoptosis was induced by actinomycin D, and detected cumulative background levels of apoptosis over a 3‐day interval. Using this assay, we show that normal fibroblasts undergo very little apoptosis upon X‐irradiation, indicating dominance of the senescence response in this cell type. Further, apoptosis increased subtly but measurably when human mammary epithelial and skin fibroblast cells entered crisis, indicating that cell death during crisis is largely non‐apoptotic.
An Algorithm for the Physical Examination of Early Fistula Failure
Authors: Beathard Gerald A. 
Published: July 2005

ABSTRACTEvaluation of a newly created fistula 4–6 weeks after surgery should be considered mandatory. If the fistula is going to become adequate for dialysis, it will be apparent at this time. This evaluation can be accomplished by physical examination. However, it must be performed by someone who is knowledgeable. Using a systematic approach facilitates the evaluation and ensures that a problem is not overlooked. Once it is determined that the fistula is dysfunctional, the case should be immediately referred for management to an interventionalist who is experienced in dealing with early fistula failure. The majority of these cases can be salvaged.
VITAMIN D IN HEALTH AND DISEASE: Vitamin D for Health and in Chronic Kidney Disease
Authors: Holick Michael F. 
Published: July 2005

ABSTRACTVitamin D is taken for granted and is not appreciated for its importance in overall health and well‐being. Vitamin D, known as the sunshine vitamin, is appreciated as being important for the prevention of rickets in children. It is now recognized that vitamin D is important for not only the growing skeleton, but for the maintenance of a healthy musculoskeletal system throughout life. Vitamin D deficiency in adults precipitates and exacerbates osteoporosis and causes the painful bone disease osteomalacia. The revelation that vitamin D is biologically inactive and requires sequential hydroxylations in the liver and kidney to form 1,25‐dihydroxyvitamin D helps explain why patients with renal failure are often resistant to vitamin D and suffer from secondary hyperparathyroidism and renal osteodystrophy. In addition to its role in maintaining calcium and phosphorus homeostasis, vitamin D is now being recognized as important for maintaining maximum muscle strength and for the prevention of many chronic diseases, including type I diabetes, multiple sclerosis, rheumatoid arthritis, hypertension, cardiovascular heart disease, and many common cancers. Vitamin D status is best determined by the measurement of circulating levels of 25‐hydroxyvitamin D. Vigilance for maintaining a 25‐hydroxyvitamin D level of at least 20 ng/ml and preferably 30–50 ng/ml has important benefits for both healthy children and adults, as well as children and adults suffering from chronic kidney disease.