bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brain‐derived neurotrophic factor suppresses tunicamycin‐induced upregulation of CHOP in neurons
Authors: Chen Gang , Fan Zhiqin , Wang Xin , Ma Cuiling , Bower Kimberly A. , Shi Xianglin , Ke Zun‐Ji , Luo Jia 
Published: April 2007

AbstractThe accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) lumen triggers ER stress. ER stress initiates a number of specific compensatory signaling pathways including unfolded protein response (UPR). UPR is characterized by translational attenuation, synthesis of ER chaperone proteins such as glucose‐regulated protein of 78 kDa (GRP78, also known as Bip), and transcriptional induction, which includes the activation of transcription factors such as activating transcriptional factor 6 (ATF6) and C/EBP homologous protein (CHOP, also known as growth arrest and DNA damage‐inducible gene 153 [GADD153]). Sustained ER stress ultimately leads to cell death. ER functions are believed to be impaired in various neurodegenerative diseases, as well as in some acute disorders of the brain. Brain‐derived neurotrophic factor (BDNF), a member of the neurotrophin family, functions as a neuroprotective agent and rescues neurons from various insults. The molecular mechanisms underlying BDNF neuroprotection, however, remain to be elucidated. We showed that CHOP partially mediated ER stress‐induced neuronal death. BDNF suppressed ER stress‐induced upregulation/ nuclear translocation of CHOP. The transcription of CHOP is regulated by ATF4, ATF6, and XBP1; BDNF selectively blocked the ATF6/CHOP pathway. Furthermore, BDNF inhibited the induction of death receptor 5 (DR5), a transcriptional target of CHOP. Our study thus suggests that suppression of CHOP activation may contribute to BDNF‐mediated neuroprotection during ER stress responses. © 2007 Wiley‐Liss, Inc.
Sequential expression of cell‐cycle regulators and Alzheimer's disease–related proteins in entorhinal cortex after hippocampal excitotoxic damage
Authors: Hernández‐Ortega Karina , Ferrera Patricia , Arias Clorinda 
Published: April 2007

AbstractGrowing evidence suggests that one of the earliest events in the neuronal degeneration of Alzheimer's disease (AD) is aberrant cell‐cycle activation in postmitotic neurons, which may, in fact, be sufficient to initiate the neurodegenerative cascade. In the present study we examined whether cyclins and cyclin‐dependent kinases, molecules normally associated with cell‐cycle control, may be involved in delayed expression of altered Alzheimer's proteins in two interconnected areas, the entorhinal cortex (EC) and the dentate gyrus (DG), after a hippocampal excitotoxic lesion. Several cell‐cycle proteins of the G1 and S phases and even of the G2 phase were found to be up‐regulated in the EC after kainic acid evoked neuronal death in the hippocampus. In addition, we describe the progressive expression of two Alzheimer's‐related proteins, PHF‐1 and APP, which reached higher levels immediately after the increase in G1/S‐phase markers. Hence, the results of the present study support the participation of cell‐cycle dysregulation as a key component of the process that may ultimately lead to expression of AD proteins and neuronal death in a brain area when the target site for synaptic inputs in that area is damaged by an excitotoxic insult. © 2007 Wiley‐Liss, Inc.
Increases in expression of 14‐3‐3 eta and 14‐3‐3 zeta transcripts during neuroprotection induced by Δ9‐tetrahydrocannabinol in AF5 cells
Authors: Chen Jia , Lee Chun‐Ting , Errico Stacie L. , Becker Kevin G. , Freed William J. 
Published: April 2007

AbstractThe molecular mechanisms involved in N‐methyl‐D‐aspartate (NMDA)‐induced cell death and Δ9‐tetrahydrocannabinol (THC)‐induced neuroprotection were investigated in vitro with an AF5 neural progenitor cell line model. By microarray analysis, Ywhah, CK1, Hsp60, Pdcd 4, and Pdcd 7 were identified as being strongly regulated by both NMDA toxicity and THC neuroprotection. The 14‐3‐3 eta (14‐3‐3η; gene symbol Ywhah) and 14‐3‐3 zeta (14‐3‐3ζ; gene symbol Ywhaz) transcripts were deceased by NMDA treatment and increased by THC treatment prior to NMDA, as measured by cDNA microarray analysis and quantitative real‐time RT‐PCR. Other 14‐3‐3 isoforms were unchanged. Whereas up‐regulation of 14‐3‐3ζ expression was observed 30 min after treatment with THC plus NMDA, down‐regulation by NMDA alone was not seen until 16 hr after treatment. By Western blotting, THC increased 14‐3‐3 protein only in cells that were also treated with NMDA. Overexpression of 14‐3‐3η or 14‐3‐3ζ by transient plasmid transfection increased 14‐3‐3 protein levels and decreased NMDA‐induced cell death. These data suggest that increases in 14‐3‐3 proteins mediate THC‐induced neuroprotection under conditions of NMDA‐induced cellular stress. © 2007 Wiley‐Liss, Inc.
Glycogen is a preferred glutamate precursor during learning in 1‐day‐old chick: Biochemical and behavioral evidence
Authors: Gibbs Marie E. , Lloyd Hilary G.E. , Santa Thomas , Hertz Leif 
Published: April 2007

AbstractBead discrimination training in chicks sets in motion a tightly timed series of biochemical events, including glutamate release, increase in forebrain level of glutamate and utilization of glycogen and glucose. Inhibition of glycogen breakdown by the glycogen phosphorylase inhibitor 1,4‐dideoxy‐1,4‐imino‐D‐arabinitol (DAB) around the time of training abolishes the increase in glutamate 5 min posttraining in the left hemisphere, in spite of uninhibited glucose metabolism. It also reduces the contents of glutamate, glutamine, and aspartate in the right hemisphere. Behavioral evidence supports the conclusion that glucose breakdown serves to provide energy, whereas glycogen acts as a substrate for glutamate, glutamine, and aspartate formation, requiring both pyruvate dehydrogenation to acetyl coenzyme A and pyruvate carboxylation in astrocytes. Inhibition of memory consolidation caused by DAB or 2‐deoxyglucose (2‐DG), an inhibitor of glucose phosphorylation without effect on glycogen metabolism, was challenged by intracerebral administration of acetate, aspartate, glutamine, lactate or glucose. DAB‐mediated memory inhibition was successfully challenged by administration at 0 or 20 min posttraining of acetate (an astrocyte‐specific acetyl CoA precursor) together with aspartate, substituting for pyruvate carboxylation, or of glutamine at 0–2.5 or 30 min posttraining. 2‐DG‐mediated memory impairment was not challenged by acetate with or without aspartate at 0 time but was challenged by acetate without aspartate at 20 min. Lactate, a substrate for both dehydrogenation and pyruvate carboxylation challenged both DAB and 2‐DG. Doses of DAB and 2‐DG which, on their own were subeffective, were not additive, further supporting the existence of one pathway using glucose and another using glycogen. © 2007 Wiley‐Liss, Inc.
QNQKE targeting motif for the SMN‐Gemin multiprotein complexin neurons
Authors: Zhang Honglai , Xing Lei , Singer Robert H. , Bassell Gary J. 
Published: April 2007

AbstractSpinal muscular atrophy (SMA) is a heritable neurodegenerative disease affecting motor neurons that is caused by the impaired expression of the full‐length form of the survival of motor neuron protein (SMN), which may have a specialized function in neurons related to mRNA localization. We have previously shown that a population SMN complexes contain Gemin ribonucleoproteins and traffic in the form of granules to neuronal processes and growth cones of cultured neurons. A QNQKE sequence within exon 7 has been shown to be necessary for both cytoplasmic localization of SMN and axonal function. Here we show that the QNQKE sequence can influence the nucleocytoplasmic distribution of the SMN‐Gemin complex and its localization into neuronal processes. QNQKE exerted a stronger effect on SMN localization in primary neurons compared with COS‐7 cells. By using double‐label fluorescence in situ hybridization and immunofluorescence, SMN granules within neuronal processes colocalized with poly‐(A) mRNA and PABP. These findings provide further evidence in support of a neuronal function for SMN and motivation to investigate for impaired assembly and/or localization of mRNP complexes as an underlying cause of SMA. © 2007 Wiley‐Liss, Inc.
Neuronal PAS domain protein 1 regulates tyrosine hydroxylase level in dopaminergic neurons
Authors: Teh Christina H.L. , Loh Chin Chieh , Lam Kevin K.Y. , Loo Jia Min , Yan Tie , Lim Tit Meng 
Published: April 2007

AbstractCatecholamines (dopamine, norepinephrine, and epinephrine) are all synthesized from a common pathway in which tyrosine hydroxylase (TH) is the rate‐limiting enzyme. Dopamine is the main neurotransmitter present in dopaminergic neurons of the ventral midbrain, where dysfunction of these neurons can lead to Parkinson's disease and schizophrenia. Neuronal PAS domain protein 1 (NPAS1) was identified as one of the genes up‐regulated during dopaminergic MN9D cell differentiation. We found that there was a corresponding decrease in TH level during MN9D differentiation. Overexpression and siRNA experiments revealed that NPAS1, in concert with ARNT, negatively regulates the expression of TH and that this regulation is mediated by a direct binding of NPAS1 on the TH promoter. Expression studies also confirmed a decrease in TH level in the ventral midbrain during mouse development, concomitant with an increase in NPAS1 level. These results suggest that NPAS1 plays a novel and important role in regulating TH level of dopaminergic neurons in the ventral midbrain during development. © 2007 Wiley‐Liss, Inc.
Distributing a fixed amount of cyclic loading to tendon explants over longer periods induces greater cellular and mechanical responses
Authors: Devkota Aaditya C. , Tsuzaki Mari , Almekinders Louis C. , Banes Albert J. , Weinhold Paul S. 
Published: April 2007

AbstractTendon overuse injuries are a major source of clinical concern. Cyclic loading causes material damage and induces biochemical responses in tendon. The purpose of this study was to examine the biochemical and biomechanical tendon response after applying cyclical loading over varying durations. Avian flexor digitorum profundus tendons were loaded (3 or 12 MPa) to a fixed number of cycles across either 1 or 12 days in vitro. The tendon response evaluations included biomechanical data gathered during loading and subsequent failure testing. Evaluations also included cellular viability, cell death, and proteoglycan, collagen, collagenase, and prostaglandin E2 (PGE2) content measurements obtained from tissue specimens and media samples. Significant strains (up to 2%) accumulated during loading. Loading to 12 MPa significantly reduced maximum stress (33% and 27%) and energy density (42% and 50%) when applied across 1 or 12 days, respectively. Loading to 3 MPa also caused a 40% reduction in energy density, but only when applied across 12 days. Cell death and collagenase activity increased significantly with increasing magnitude and duration. However, no differences occurred in cell viability or collagen content. Glycosaminoglycan content increased 50% with load magnitude, while PGE2 production increased 2.5‐fold with loading magnitude and 11‐fold with increased duration. Mechanical fatigue‐induced mechanical property changes were exhibited by the tendons in response to increased loading magnitude across just 1 day. However, when the same loading was applied over a longer period, most outcomes were magnified substantially, relative to the short duration regimens. This is presumably due to the increased response time for the complex cellular response to loading. A key contributor may be the inflammatory mediator, PGE2, which exhibited large magnitude and duration dependent increases to cyclic loading. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1078–1086, 2007
In vivo effects of coating loaded and unloaded Ti implants with collagen, chondroitin sulfate, and hydroxyapatite in the sheep tibia
Authors: Rammelt Stefan , Heck Christian , Bernhardt Ricardo , Bierbaum Susanne , Scharnweber Dieter , Goebbels Jürgen , Ziegler Jörg , Biewener Achim , Zwipp Hans 
Published: April 2007

AbstractThe in vivo effects of coating titanium implants with organic extracellular matrix molecules were examined in the sheep tibia. Titanium screws (5.0 mm) were coated with type I collagen (Ti/Coll) or type I collagen and chondroitin sulfate (Ti/Coll/CS) by biomimetic fibrillogenesis. Uncoated screws (Ti) and screws coated with hydroxyapatite (Ti/HA) served as control. Six adult female sheep received one screw of each type to stabilize a midshaft tibial fracture with external fixation. Four cylindrical implants of 4‐mm outer diameter and 3.3‐mm inner diameter with the same coatings were inserted into the tibial head. No pin track infections were seen at the time of implant retrieval 6 weeks after implantation. Extraction torque was greater for Ti/HA (1181 Nmm) and Ti/Coll/CS (1088 Nmm) compared to Ti/Coll (900 Nmm) and Ti (904 Nmm) [N.S.]. Newly formed bone was noted around all coated screws within the medullary cavity. Macrophage and osteoclast activity was significantly reduced around Ti/Coll/CS in both types of implants compared to uncoated controls (p < 0.05). Osteoblast activity was significantly increased around loaded Ti/Coll and Ti/Coll/CS screws compared to uncoated Ti screws (p < 0.05). Microtomographic evaluation (SRµCT) revealed no significant differences in new bone formation around the unloaded tibial head implants.Coating of external fixation devices with of type I collagen and chondroitin sulfate appears to have similar effects with respect to stability and bone healing as HA but with less osteoclast activity. These findings were more pronounced under loaded than unloaded conditions in the sheeptibia. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1052–1061, 2007
Effects of traditional storage practices of small‐scale organic farmers on potato quality
Authors: Katundu Mangani GC , Hendriks Sheryl L , Bower John P , Siwela Muthulisi 
Published: April 2007

AbstractA study was undertaken to investigate the effect of traditional storage practices of small‐scale organic farmers in rural KwaZulu–Natal on the quality of potatoes. Changes in sugar and starch content were monitored. A preference ranking test was used to investigate preference for organically produced potatoes left in situ, stored under ambient conditions in a farmer's house and under controlled conditions (7 °C and 90% relative humidity) for 2, 4 and 6 weeks. The lowest and highest sugar levels were observed in potatoes stored in situ and under controlled conditions, respectively. Potatoes stored in situ were significantly preferred by sensory panellists (P < 0.05) over those stored in both the farmer's house and in controlled storage. Preference rank scores were negatively correlated to total sugar content and positively correlated to starch content although not all correlations were statistically significant. This gives an indication that other factors not investigated in this study, like glycoalkaloid content, may have contributed to the acceptability of potatoes from different modes of storage and requires further investigation. However, the study clearly shows that leaving potatoes in situ as a method of storage maintains desirable sensory properties of potatoes by maintaining low sugar levels and higher starch content. Copyright © 2007 Society of Chemical Industry
In vitro starch digestibility of fresh and sun‐dried faba beans (Vicia faba L.)
Authors: Bello‐Pérez Luis A , Islas‐Hernández José Juan , Rendón‐Villalobos J Rodolfo , Agama‐Acevedo Edith , Morales‐Franco Leticia , Tovar Juscelino 
Published: April 2007

AbstractFresh and sun‐dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 °C and analysed for available starch (AS), resistant starch (RS) and fibre‐associated resistant starch (FARS) contents as well as α‐amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The α‐amylolysis rate decreased with increasing storage time, i.e. long‐stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. Copyright © 2007 Society of Chemical Industry
Potential nutritive value and tannin bioassay of selected Acacia species from Kenya
Authors: Osuga Isaac M , Maindi Catherine N , Abdulrazak Shaukat A , Nishino Naoki , Ichinohe Toshiyoshi , Fujihara Tsutomu 
Published: April 2007

AbstractSix Acacia forage species–A. brevispica, A. elatior, A. mellifera, A. nilotica, A. senegal and A. seyal—were analysed for their chemical composition, including phenolics and rumen fermentation characteristics. In vitro gas production technique was used to study the rumen fermentation characteristics and the effect of tannins present in the browse forages on in vitro fermentation by including polyethylene glycol (PEG‐6000) in the incubation. The forages had high crude protein content (145.7–270.1 g kg−1 DM) and low to moderate content of neutral detergent fibre (220.2–442.8 g kg−1 DM). The forages had variable content of total extractable phenolics ranging from 18.4 to 384.2 g kg−1 DM and total extractable tannins ranging from 7.1 to 364.8 g kg−1 DM (tannic acid equivalent). Fractionation of the condensed tannin flavonoids showed that the delphinidin/cyanidin ratio ranged from not detected:100 to 71:29. The gas production potential ranged from 28.4 to 40.8 mL gas 0.2 g−1 DM. The rate of gas production was highest in A. elatior and lowest in A. nilotica. Addition of PEG‐6000 increased gas production significantly (P < 0.05) in all species except A. mellifera. PEG‐6000 addition did not have any significant effect on in vitro true dry matter and organic matter degradability but decreased the partitioning factor in all the species. Gas production and degradability parameters correlated positively with the CP content and negatively with the fibre and phenolics contents. Based on chemical composition, gas production and degradability, the forages have high potential nutritive value, especially as supplements to low‐quality feeds in the tropics and particularly during the dry season. However, the presence of tannins in terms of high levels and biological antinutritive activity may limit the nutritive potential of some of the forages, such as A. seyal and A. nilotica. Copyright © 2007 Society of Chemical Industry
Study of sensory evaluation, consumer acceptability, affordability and market price of rice
Authors: Tomlins Keith , Manful John , Gayin Joseph , Kudjawu Bernice , Tamakloe Iris 
Published: April 2007

AbstractThe purpose of the study was to evaluate consumer acceptance, affordability and market value of a prototype parboiled rice (PPR) in relation to three local samples and a high‐value imported one. While descriptive sensory evaluation and central location testing are used to evaluate consumer acceptability, this study suggests that affordability and market price of rice can also be assessed. The PPR was acceptable and the suggested market price was influenced by both affordability and acceptability. Acceptance scores suggested a potential higher price; consumers discounted the prototype rice and the extent depended on affordability. The concept of consumer acceptability and affordability varied widely among consumers and this was related to the market price, demographics and attitudes towards rice. Sensory attributes associated with quality were positively related with price but negatively with affordability. Acceptability was related to rice consumption and purchasing behaviour, whereas affordability was associated with income, gender and quality perception. Low affordability groups knew the least about the benefits of rice. The implications are discussed. Copyright © 2007 Society of Chemical Industry
5‐ALA for photodynamic photorejuvenation—optimization of treatment regime based on normal‐skin fluorescence measurements
Authors: Christiansen Kaare , Bjerring Peter , Troilius Agneta 
Published: April 2007

AbstractBackground and ObjectivesPhotodynamic therapy using 20% 5 aminolevulinic acid (5‐ALA) has recently been introduced as a new tool in optical skin rejuvenation. The primary objective of this study was to optimize incubation time, the topical delivery mechanism (vehicle) and the concentration of 5‐ALA by detecting the dynamic changes of normal skin after 5‐ALA application. The secondary objective was to develop a treatment regime which minimizes post‐treatment photosensitivity.Study Design/Materials and MethodsSkin fluorescence distribution patterns after topical application of low concentrations of 5‐ALA (0.5% and 1% preparations encapsulated in liposomes), were investigated. Twenty percent 5‐ALA in moisturizing cream was used as a control. Ten healthy volunteers participated, and skin fluorescence was documented by fluorescent photography. The fluorescent intensity was measured in % of maximum obtained fluorescence after 3 hours 5‐ALA application.ResultsSkin fluorescence intensity after topical application of 0.5% and 1% non‐occluded liposome‐encapsulated 5‐ALA application was heterogeneous distributed and reached saturation level after approximate 2 hours. The maximal fluorescence for 0.5% and 1% 5‐ALA treated areas was 4.2% (SD: 3.5%) and 2.4% (SD: 2%), respectively, and this difference was statistically significant (P = 0.036). The fluorescence decayed linearly shortly (within 15 minutes) after end of application and was back to baseline within 8 hours. In contrast, the fluorescence of areas treated more than 1 hour with 20% 5‐ALA was very uniform and a linear relationship (r2 = 0.998) to the incubation time (0–3 hours) was registered. Furthermore, fluorescence intensity (15.2–57.9%) continued to increase after the end of 5‐ALA application. The maximum fluorescence reach a level of 1.6–9 times the fluorescence measured by end of the 5‐ALA application and occurred 8:13 hours (SD: 0:49 hours) after the end of 20% 5‐ALA application. The average skin surface fluorescence induced by the liposome‐encapsulated 0.5% 5‐ALA applied for longer than 2 hours, was found to be statistically equal (P = 0.47) to the average measured skin surface fluorescence (4.2%) obtained after 30 minutes exposure to 20% 5‐ALA cream (4.3%).ConclusionChanging the 5‐ALA vehicle from a moisturizing cream to liposome encapsulation, the 5‐ALA concentration can be lowered by a factor of 40, and still induce the same skin fluorescence and at the same time eliminates the need for occlusion. The low post‐treatment fluorescence also suggests a significantly reduced risk of post‐treatment phototoxicity. Lasers Surg. Med. 39: 302–310, 2007. © 2007 Wiley‐Liss, Inc.