bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual strength prediction of multiple cracked stiffened panels
Authors: LABEAS G. , DIAMANTAKOS J. 
Published: March 2006

ABSTRACTPrediction of the coalescence of adjacent cracks is critical for residual strength estimation of structures under multiple site damage conditions. A methodology successfully developed for the case of crack link‐up prediction of un‐stiffened plates, is extended for the case of typical cracked stiffened aircraft panels. The proposed link‐up criterion is based on the change in the magnitudes of elastic and plastic strain energies of the stiffened panel, before and after the cracks coalesce. The strain energy magnitudes of interest are calculated using non‐linear elastic–plastic finite‐element analysis. For the application and verification of the method, experimental results from the open literature are used. Residual strength values calculated by the proposed methodology are in good agreement with the experimental results. The present criterion provides superior results when compared to the existing and commonly applied link‐up criteria.
Post‐natal development of the porcine microbiota composition and activities
Authors: Konstantinov Sergey R. , Awati Ajay A. , Williams Barbara A. , Miller Bevis G. , Jones Philip , Stokes Christopher R. , Akkermans Antoon D. L. , Smidt Hauke , De Vos Willem M. 
Published: March 2006

SummaryThe current study describes the development of the porcine microbiota and its metabolic activities during the neonatal and weaning period. Using 16S rRNA‐based approaches, we first analysed the ileal and colonic microbiota of neonatal piglets at days 2, 5 and 12 after birth. To further investigate the effect of weaning at 3 weeks of age, 19‐day‐old piglets (n = 64) were randomly allocated into two groups. Half of the piglets remained with their sows throughout the study, while the remaining piglets were weaned. As revealed by sequence analysis of 16S rRNA gene amplicons, the samples of 2‐day‐old piglets harboured a consortium of bacteria related to Escherichia coli, Shigella flexneri, Lactobacillus sobrius, Lactobacillus reuteri and Lactobacillus acidophilus. Moreover, species‐specific real‐time polymerase chain reaction assays unveiled that L. sobrius and L. reuteri predominated in the ileal samples of the neonatal and unweaned piglets with population levels up to 7 × 108 cells per gram of lumen content. Following weaning, however, these two lactobacilli were detected at significantly lower levels (< 103) in the ileal samples. Furthermore, a shift in composition and metabolic activities of the predominant microbiota, and emergence of clostridia and E. coli, were encountered in the intestinal samples of the piglets after the early post‐weaning period.
Speed‐up Technique for a Local Automatic Colour Equalization Model
Authors: Artusi A. , Gatta C. , Marini D. , Purgathofer W. , Rizzi A. 
Published: March 2006

Abstract In this paper we propose a speed‐up technique for a local automatic colour equalization operator derived from a model of the human vision system. This method is characterized by local and global filtering effects, that simultaneously achieve different equalization tasks e.g. performing colour and lightness constancy, realizing dynamic image data driven stretching, controlling the contrast. We describe a way to quickly create a filtering mapping function to perform the global component of the mapping. This method is based on singular value decomposition (SVD) applied to sampled and filtered points in the input image. Then, the local information is added computing the basic algorithm on a neighbourhood of each input pixel. A slight quality loss is the price that we have to pay for a speed‐up of more than two orders of magnitude of the basic algorithm. We present the results on several images and discuss the efficiency and the drawbacks of the speed‐up technique.
Structure and function of the eastern grey kangaroo (Macropus giganteus) foot thump
Authors: Bender H. 
Published: March 2006

AbstractMost species of the family Macropodidae (kangaroos and wallabies) make a distinctive foot thump by striking the ground with their hind feet when they detect potential danger. I used the eastern grey kangarooMacropus giganteusas a model to examine (1) the acoustic characteristics and structure of the thump, (2) the social context in which free‐ranging kangaroos thumped when approached by a human observer on foot and (3) the intended recipient of the signal. Thumps were about two‐thirds of a second in length, generally composed of two noisy pulses, and had the majority of the signal energy below 7 kHz. Only adult kangaroos, of both sexes, were observed to thump. A higher proportion of solitary kangaroos thumped than grouped kangaroos, and a higher proportion of kangaroos thumped when visibility was poor, either because of habitat type or low light levels. Given the context in which thumps were given, the foot thump appears to be a signal to a potential predator with three possible functions: to startle, signal detection or deter pursuit.
Sulfated polymannuroguluronate, a novel anti‐acquired immune deficiency syndrome drug candidate, blocks neuroinflammatory signalling by targeting the transactivator of transcription (Tat) protein
Authors: Hui Bin , Xia Wei , Li Jing , Wang Limei , Ai Jing , Geng Meiyu 
Published: March 2006

AbstractImpaired inflammatory functions may be critical factors in the mechanisms of severe CNS disorders classified as the human immunodeficiency virus‐1 (HIV‐1)‐associated dementia (HAD). Evidence indicates that a viral gene product, the transactivator of transcription protein (Tat), can markedly contribute to these events. We herein report that sulfated polymannuroguluronate (SPMG), a novel anti‐acquired immunodeficiency syndrome drug candidate now in a phase II clinical trial, significantly reversed Tat‐induced release of pro‐inflammatory cytokines [tumour necrosis factor (TNF)‐α, interleukin (IL)‐1β) and IL‐6] and dose dependently decreased the accumulation of reactive oxygen species and nitric oxide in THP‐1 cells. Furthermore, SPMG potently arrested Tat‐triggered protein kinase C (PKC)‐dependent PKC‐μ activation, and blocked the downstream extracellular‐signal regulated kinase 1/2‐ and c‐jun amino‐terminal kinase‐mediated signalling pathways. These molecular mechanisms could be attributed to the fact that SPMG preferentially bound to the basic domain (amino acids 47–57) of the Tat protein with high affinity (KD ≈ 8.69 × 10−10 m), leading to abrogation of Tat‐mediated neuroinflammation and neurotoxicity. These data demonstrate that SPMG might serve as a valuable therapeutic intervention for Tat‐induced profound pro‐inflammatory effects in the brain, and subsequent pathologic events of HAD.
The multidrug resistance protein 1 (Mrp1), but not Mrp5, mediates export of glutathione and glutathione disulfide from brain astrocytes
Authors: Minich Tobias , Riemer Jan , Schulz Jörg B. , Wielinga Peter , Wijnholds Jan , Dringen Ralf 
Published: March 2006

AbstractAstrocytes play an important role in the glutathione (GSH) metabolism of the brain. To test for an involvement of multidrug resistance protein (Mrp) 1 and 5 in the release of GSH and glutathione disulfide (GSSG) from astrocytes, we used astrocyte cultures from wild‐type, Mrp1‐deficient [Mrp1(–/–)] and Mrp5‐deficient [Mrp5(–/–)] mice. During incubation of wild‐type or Mrp5(–/–) astrocytes, GSH accumulated in the medium at a rate of about 3 nmol/(h.mg), whereas the export of GSH from Mrp1(–/–) astrocytes was only one‐third of that. In addition, Mrp1(–/–) astrocytes had a 50% higher specific GSH content than wild‐type or Mrp5(–/–) cells. The presence of 50 μmof the Mrp inhibitor MK571 inhibited the rate of GSH release from wild‐type and Mrp5(–/–) astrocytes by 60%, but stimulated at the low concentration of 1 μmGSH release by 40%. In contrast, both concentrations of MK571 did not affect GSH export from Mrp1(–/–) astrocytes. Moreover, in contrast to wild‐type and Mrp5(–/–) cells, GSSG export during H2O2stress was not observed for Mrp1(–/–) astrocytes. These data demonstrate that in astrocytes Mrp1 mediates 60% of the GSH export, that Mrp1 is exclusively responsible for GSSG export and that Mrp5 does not contribute to these transport processes.
Substance P initiates NFAT‐dependent gene expression in spinal neurons
Authors: Seybold V. S. , Coicou L. G. , Groth R. D. , Mermelstein P. G. 
Published: March 2006

AbstractPersistent hyperalgesia is associated with increased expression of proteins that contribute to enhanced excitability of spinal neurons, however, little is known about how expression of these proteins is regulated. We tested the hypothesis that Substance P stimulation of neurokinin receptors on spinal neurons activates the transcription factor nuclear factor of activated T cells isoform 4 (NFATc4). The occurrence of NFATc4 in spinal cord was demonstrated with RT‐PCR and immunocytochemistry. Substance P activated NFAT‐dependent gene transcription in primary cultures of neonatal rat spinal cord transiently transfected with a luciferase DNA reporter construct. The effect of Substance P was mediated by neuronal neurokinin‐1 receptors that coupled to activation of protein kinase C, l‐type voltage‐dependent calcium channels, and calcineurin. Interestingly, Substance P had no effect on cyclic AMP response element (CRE)‐dependent gene expression. Conversely, calcitonin gene‐related peptide, which activated CRE‐dependent gene expression, did not activate NFAT signaling. These data provide evidence that peptides released from primary afferent neurons regulate discrete patterns of gene expression in spinal neurons. Because the release of Substance P and calcitonin gene‐related peptide from primary afferent neurons is increased following peripheral injury, these peptides may differentially regulate the expression of proteins that underlie persistent hyperalgesia.
Down regulation of trk but not p75NTR gene expression in single cholinergic basal forebrain neurons mark the progression of Alzheimer's disease
Authors: Ginsberg Stephen D. , Che Shaoli , Wuu Joanne , Counts Scott E. , Mufson Elliott J. 
Published: March 2006

AbstractDysfunction of cholinergic basal forebrain (CBF) neurons of the nucleus basalis (NB) is a cardinal feature of Alzheimer's disease (AD) and correlates with cognitive decline. Survival of CBF neurons depends upon binding of nerve growth factor (NGF) with high‐affinity (trkA) and low‐affinity (p75NTR) neurotrophin receptors produced within CBF neurons. Since trkA and p75NTR protein levels are reduced within CBF neurons of people with mild cognitive impairment (MCI) and mild AD, trkA and/or p75NTR gene expression deficits may drive NB degeneration. Using single cell expression profiling methods coupled with custom‐designed cDNA arrays and validation with real‐time quantitative PCR (qPCR) and in situ hybridization, individual cholinergic NB neurons displayed a significant down regulation of trkA, trkB, and trkC expression during the progression of AD. An intermediate reduction was observed in MCI, with the greatest decrement in mild to moderate AD as compared to controls. Importantly, trk down regulation is associated with cognitive decline measured by the Global Cognitive Score (GCS) and the Mini‐Mental State Examination (MMSE). In contrast, there is a lack of regulation of p75NTR expression. Thus, trk defects may be a molecular marker for the transition from no cognitive impairment (NCI) to MCI, and from MCI to frank AD.
Cortical choline transporter function measuredin vivousing choline‐sensitive microelectrodes: clearance of endogenous and exogenous choline and effects of removal of cholinergic terminals
Authors: Parikh V. , Sarter M. 
Published: March 2006

AbstractThe capacity of the high‐affinity choline transporter (CHT) to import choline into presynaptic terminals is essential for acetylcholine synthesis. Ceramic‐based microelectrodes, coated at recording sites with choline oxidase to detect extracellular choline concentration changes, were attached to multibarrel glass micropipettes and implanted into the rat frontoparietal cortex. Pressure ejections of hemicholinium‐3 (HC‐3), a selective CHT blocker, dose‐dependently reduced the uptake rate of exogenous choline as well as that of choline generated in response to terminal depolarization. Following the removal of CHTs, choline signal recordings confirmed that the demonstration of potassium‐induced choline signals and HC‐3‐induced decreases in choline clearance require the presence of cholinergic terminals. The results obtained from lesioned animals also confirmed the selectivity of the effects of HC‐3 on choline clearance in intact animals. Residual cortical choline clearance correlated significantly with CHT‐immunoreactivity in lesioned and intact animals. Finally, synaptosomal choline uptake assays were conducted under conditions reflectingin vivobasal extracellular choline concentrations. Results from these assays confirmed the capacity of CHTs measuredin vivoand indicated that diffusion of substrate away from the electrode did not confound thein vivofindings. Collectively, these results indicate that increases in extracellular choline concentrations, irrespective of source, are rapidly cleared by CHTs.
Characterization of an extended receptive ligand repertoire of the human olfactory receptor OR17‐40 comprising structurally related compounds
Authors: Jacquier Valérie , Pick Horst , Vogel Horst 
Published: March 2006

AbstractMolecular properties of odorant compounds essential for activation of the human olfactory receptor hOR17‐40 were investigated using a collection of 23 variants of its cognate ligand helional. Coupling receptor activation to an optically detectable intracellular Ca2+ ion flux allowed dose‐dependent screening of different odorant molecules in human embryonic kidney (HEK)293 cells. We found an extended collection of activating ligands and provide first evidence for hOR17‐40‐specific antagonists. The C‐terminal fusion of enhanced green fluorescent protein to the hOR17‐40 retained full receptor function and permitted the selection of cells with defined receptor expression levels, which was an essential step for optimizing our screening protocol. Interestingly, cells with a low EGFP fluorescence intensity exhibited efficient hOR17‐40 cell surface targeting and odorant‐evoked signal transduction; in contrast, highly fluorescent cells displayed mainly incorrectly targeted, intracellular receptors. Fluorescence‐activated cell sorting was used to separate hOR17‐40‐expressing cells on the basis of their endogenous EGFP fluorescence intensity, thereby increasing the fraction of odorant‐responsive cells to up to 80% of the total cell number.
Expression of the Otx2 homeobox gene in the developing mammalian brain: embryonic and adult expression in the pineal gland
Authors: Rath Martin F. , Muñoz Estela , Ganguly Surajit , Morin Fabrice , Shi Qiong , Klein David C. , Møller Morten 
Published: March 2006

AbstractOtx2 is a vertebrate homeobox gene, which has been found to be essential for the development of rostral brain regions and appears to play a role in the development of retinal photoreceptor cells and pinealocytes. In this study, the temporal expression pattern of Otx2 was revealed in the rat brain, with special emphasis on the pineal gland throughout late embryonic and postnatal stages. Widespread high expression of Otx2 in the embryonic brain becomes progressively restricted in the adult to the pineal gland. Crx (cone–rod homeobox), a downstream target gene of Otx2, showed a pineal expression pattern similar to that of Otx2, although there was a distinct lag in time of onset. Otx2 protein was identified in pineal extracts and found to be localized in pinealocytes. Total pineal Otx2 mRNA did not show day–night variation, nor was it influenced by removal of the sympathetic input, indicating that the level of Otx2 mRNA appears to be independent of the photoneural input to the gland. Our results are consistent with the view that pineal expression of Otx2 is required for development and we hypothesize that it plays a role in the adult in controlling the expression of the cluster of genes associated with phototransduction and melatonin synthesis.
Suppressive effects of 4‐phenylbutyrate on the aggregation of Pael receptors and endoplasmic reticulum stress
Authors: Kubota Kyoko , Niinuma Yoshifumi , Kaneko Masayuki , Okuma Yasunobu , Sugai Mami , Omura Tomohiro , Uesugi Mai , Uehara Takashi , Hosoi Toru , Nomura Yasuyuki 
Published: March 2006

AbstractEndoplasmic reticulum (ER) stress is defined as an accumulation of unfolded proteins in the endoplasmic reticulum. 4‐phenylbutyrate (4‐PBA) has been demonstrated to promote the normal trafficking of the ΔF508 cystic fibrosis transmembrane conductance regulator (CFTR) mutant from the ER to the plasma membrane and to restore activity. We have reported that 4‐PBA protected against cerebral ischemic injury and ER stress‐induced neuronal cell death. In this study, we revealed that 4‐PBA possesses chemical chaperone activityin vitro, which prevents the aggregation of denatured α‐lactalbumin and bovine serum albumin (BSA). Furthermore, we investigated the effects of 4‐PBA on the accumulation of Parkin‐associated endothelin receptor‐like receptor (Pael‐R) pathologically relevant to the loss of dopaminergic neurons in autosomal recessive juvenile parkinsonism (AR‐JP). Interestingly, 4‐PBA restored the normal expression of Pael‐R protein and suppressed ER stress induced by the overexpression of Pael‐R. In addition, we showed that 4‐PBA attenuated the activation of ER stress‐induced signal transduction pathways and subsequent neuronal cell death. Moreover, 4‐PBA restored the viability of yeasts that fail to induce an ER stress response under ER stress conditions. These results suggest that 4‐PBA suppresses ER stress by directly reducing the amount of misfolded protein, including Pael‐R accumulated in the ER.
Identification and characterization of two novel splice forms of GRIP1 in the rat brain
Authors: Charych Erik I. , Li Rongwen , Serwanski David R. , Li Xuejing , Miralles Celia P. , Pinal Noelia , De Blas Angel L. 
Published: March 2006

AbstractWe cloned two novel alternatively‐spliced mRNA isoforms of glutamate receptor interacting protein 1 (GRIP1) which we named GRIP1d and GRIP1e 4–7. GRIP1d is a 135 kDa, 7‐PDZ‐domain variant of GRIP1, containing the 12 amino acid C‐terminus originally described for the 4‐PDZ‐domain GRIP1c 4–7. GRIP1e 4–7 is a 75 kDa 4‐PDZ‐domain variant of GRIP1, containing the 12 amino acid C‐terminus originally described for the 7‐PDZ‐domain GRIP1a/b. Northern blots indicated that GRIP1d mRNA is 5.1 kb long and abundant in brain. An antibody to the C‐terminus of the 75 kDa GRIP1c 4–7 also recognized an abundant 135 kDa protein, consistent with the predicted size of GRIP1d. Similarly, an antibody to the C‐terminus of the 135 kDa GRIP1a/b also recognized a low abundance 75 kDa protein, consistent with the predicted size of GRIP1e 4–7. Immunocytochemistry of hippocampal cultures and intact brain using these antibodies showed that (i) these isoforms are present in both GABAergic and glutamatergic synapses, and (ii) the isoforms co‐localize in individual synapses. While GRIP1a/b isoforms are abundant in interneurons and highly concentrated in GABAergic presynaptic terminals, the isoforms recognized by the antibody to the C‐terminus common to GRIP1c 4–7 and GRIP1d are much less abundant in interneurons and preferentially concentrate at the postsynaptic complex.
Effect of ammonia on astrocytic glutamate uptake/release mechanisms
Authors: Rose Christopher 
Published: March 2006

AbstractHyperammonemic disorders such as acute liver failure (ALF) or urea cycle enzymopathies are associated with hyperexcitability, seizures, brain edema and increased extracellular brain glutamate. Mechanisms responsible for increased glutamate content in the extracellular space of the brain include decreased uptake by perineuronal astrocytes and/or increased release from neurons and/or astrocytes. Exposure of astrocytes to millimolar concentrations of ammonia results in cell swelling, loss of expression of the glutamate transporters excitatory amino acid transporter (EAAT‐1) and EAAT‐2 and increased release of glutamate. Three distinct mechanisms are theoretically possible to explain ammonia‐induced glutamate release from astrocytes namely: release due to swelling; reversal of glutamate transporters and due to Ca2+‐dependent vesicular release. Recent identification of vesicular docking and fusion proteins in astrocytes together with glutamate‐release (due to intracellular alkanization and mobilization of intracellular Ca2+‐stores) studies implies that vesicular release is a predominant mechanism responsible for ammonia‐induced release of glutamate from astrocytes.
Carboplatin for treatment of a Sertoli cell tumor in a mallard (Anas platyrhynchos)
Authors: Childs‐Sanford S. E. , Rassnick K. M. , Alcaraz A. 
Published: March 2006

AbstractA 13‐year‐old male mallard was diagnosed with a non‐resectable Sertoli cell tumor involving the left testis. The duck was treated with four doses of single‐agent carboplatin given at 4‐ to 5‐week intervals. Heteropenia, 2 weeks after each treatment, was the acute dose‐limiting toxicity. The tumor reduced in size by 25%, and the duck's clinical condition improved for 12 months. Sertoli cell tumors are rare in birds, and this is the first report, to our knowledge, of attempted chemotherapy treatment in the veterinary literature.
Epidermal growth factor receptor expression in feline oral squamous cell carcinomas
Authors: Looper J. S. , Malarkey D. E. , Ruslander D. , Proulx D. , Thrall D. E. 
Published: March 2006

AbstractFeline oral squamous cell carcinomas (SCC) have a poor prognosis despite aggressive treatment with surgery, radiation and anticancer drugs. Overexpression of the epidermal growth factor receptor (EGFR), a membrane‐bound tyrosine kinase receptor, has been found in many human epithelial neoplasms, including oral SCC. EGFR overexpression has been associated with advanced disease and a poor prognosis. The purpose of this study was to determine whether feline oral SCC express EGFR. Thirteen formalin‐fixed paraffin wax‐embedded biopsy samples from feline oral SCC were analysed for EGFR expression using immunohistochemistry. Nine of 13 tumours (69%) were positive for EGFR expression, suggesting that altered EGFR expression plays a role in feline oral SCC and provides a rationale for a potential clinical benefit using EGFR inhibitors in combination with conventional treatments.
The cognitive complaint interview (CCI)
Authors: THOMAS‐ANTÉRION Catherine , HONORÉ‐MASSON Sandrine , LAURENT Bernard 
Published: March 2006

ABSTRACTBackground:  The objective is to devise a cognitive complaint interview (CCI) that can be used in the early stages of dementia. The interview consists in two questions about general memory functioning and eight questions about more particular cognitive complaints: a ‘yes’ response to one of these questions reflects what we refer to as a memory complaint. The administration of this interview takes approximately 10 min.Methods:  One hundred and ninety‐five interviews were conducted. We studied 73 normal subjects, 73 patients (Alzheimer's disease (AD), n = 49; depression, n = 24) and 49 caregivers for AD patients.Results:  The number of ‘yes’ responses in the CCI was not accounted by age, gender, educational level or Mini‐Mental State Examination. Only the AD subgroup presents more general complaints than the control subgroup. Only three out of the 73 controls (<4.1%) complained more than three times, which suggests that a complaint score superior to three (obviously without mood, social or sensorial explanations) should lead to additional testing. The AD patient's feelings may be similar to those of his family. Nevertheless, once the patient has a clear dementia syndrome, the patient and/or their caregiver may stop complaining and develop an anosognosia.Conclusion:  This CCI could constitute a tool to provide an etiological explanation of the memory complaints.