bluuebunny/crossref_metadata_2025_split huggingface dataset:
An investigation into the availability and economic accessibility of food items in rural and urban areas of Northern Ireland
Authors: Furey Sinead , Farley Heather , Strugnell Christopher 
Published: March 2003

AbstractThe question of access to food has three components: physical access to food, financial access to food and access to information about food. This study explores the issue of financial access to food. The affordability of food is a major consideration for consumers, an important marketing tool for retailers and a principal theme in food policy. Research methods included a comparative shopping exercise (shopping basket analysis) in 109 stores across four towns (two urban and two rural) in Northern Ireland. Store type included multiples (major supermarket chains) and symbol group stores (those stores operating under a franchise from one main buying group). Results indicate that in the main it is cheaper to buy from the multiples, shopping from a symbol group store can incur cost penalties of up to 39.4% above the multiples’ prices. Price disparities, analysed using z‐scores, were apparent between towns and across store types. Similarly, an availability audit of foodstuffs portrayed the multiples as the most comprehensive from which to shop, whereas symbol group stores fared poorly in the availability of fresh green vegetables, carcass meat and wholemeal breads. This is an important issue because it plays an integral part in the health inequality debate and also relates to social exclusion. Fundamentally, financial access to food impinges upon the whole question of food‐purchasing behaviour in terms of accessibility, affordability and availability. Therefore, economic access to food can be used as a useful precursor to a comprehensive analysis of food access in its entirety. It is also useful as an indicator of social exclusion. This study seeks to inform and influence the food policy debate.
Cooking, recipe use and food habits of college students and nutrition educators
Authors: Hertzler Ann A. , Bruce F.A. 
Published: March 2003

AbstractThe purpose of this study was to revisit Lewin's gatekeeper theory to observe current food role patterns (cooking experience, recipe sources, and both daily food consumption choices and eating out) with contemporary groups of college students (n = 292) and of nutrition educators (n = 26). Male college students equalled female students in cooking ability, use of family as a prime recipe source, and frequency of eating out, while exhibiting different food consumption excesses and deficiencies. Package labels and the Internet were most frequently identified as recipe sources by college students. Nutritionists surpassed both male and female college students in most attributes.
Estimation of income elasticities from Lorenz concentration curves: application to Canadian micro‐data
Authors: Abdel‐Ghany Mohamed , Gehlken Amy , Silver J. Lew 
Published: March 2003

AbstractThis study uses a method of estimating income elasticities of major Canadian expenditure groups. The technique is based on the implicit Engel functions derived from the Lorenz curve of permanent income and concentration curves of group‐specific expenditures. The methodology is applied to The 1996 Canadian Family Expenditure Survey. Results indicate that income elasticities for the majority of the broad expenditure categories considered in the study are inelastic and they increase monotonically with income.
Shopping orientation segments: exploring differences in store patronage and attitudes toward retail store environments among female apparel consumers
Authors: Moye Letecia N. , Kincade Doris H. 
Published: March 2003

AbstractThe purpose of this study was to identify shopping orientation segments for US female consumers. The sample included 151 women, aged 18 years and over. This research examined differences in the segments relative to store patronage preferences (i.e. department, discount, specialty), attitude toward the environment of the store selected as first choice when shopping for a specific apparel item (i.e. a dress), and demographic characteristics. Cluster analysis revealed that four shopping segments described the female consumers. The segments were named Decisive Apparel Shopper, Confident Apparel Shopper, Highly Involved Apparel Shopper, and Extremely Involved Apparel Shopper, based on several shopping factors. Differences were found among the shopping orientation segments for store of first choice, attitude and household income. Implications and future research directions are discussed.
The effect of multiwall Kraft paper or plastic bags on physico‐chemical changes in milk powder during storage at high temperature and humidity
Authors: Shakeel‐Ur‐Rehman  , Farkye Nana Y , Schaffner Andrew A 
Published: March 2003

Plastic bags have recently been introduced as an alternative to multiwall Kraft paper bags in packaging milk powder in 25‐kg sizes as it is thought that plastic bags are more durable and would preserve the quality of milk powders during storage better than paper bags. However, there is little scientific information available on the performance of plastic bags for milk powder storage. The aim of this study was to compare the properties of skimmed milk powder (SMP) packaged in plastic or paper bags. Commercially produced and packaged SMP in 25‐kg plastic or paper bags was stored at 37°C and 90% relative humidity. Samples were analysed at intervals (0, 45, 90 and 135 days) for moisture, water activity, lactic acid content, pH, insolubility index, bulk density, flowability, dispersibility and particle size. The magnitude of change in the majority of SMP properties measured during storage suggests that plastic bags are similar to paper bags in maintaining milk powder quality during storage.
Accumulation of the anandamide precursor and other N‐acylethanolamine phospholipids in infant rat models of in vivo necrotic and apoptotic neuronal death
Authors: Hansen Henrik H. , Ikonomidou Chrysanthy , Bittigau Petra , Hansen Steen Honoré , Hansen Harald S. 
Published: March 2003

It has been demonstrated that the endogenous cannabinoid receptor ligand, anandamide, and other N‐acylethanolamines (NAEs), accumulate during neuronal injury in vitro, a process that may be linked to the neuroprotective effects of NAEs. The crucial step for generation of NAEs is the synthesis of the corresponding precursors, N‐acylethanolamine phospholipids (NAPEs). However, it is unknown whether this key event for NAE formation is regulated differently in the context of insults causing necrotic or apoptotic neuronal death. To address this question, we monitored a range of cortical NAPE species in three infant rat models of in vivo neurodegeneration: (i) necrosis caused by intrastriatal injection of NMDA (25 nmol); (ii) apoptosis induced by systemic administration of the NMDA‐receptor antagonist (+)MK‐801 (3 × 0.5 mg/kg, i.p.); and (iii) apoptosis following focal necrosis triggered by concussive head trauma. A marked increase of all NAPE species was observed in both hemispheres 4 and 24 h after NMDA‐induced injury, with a relatively larger increase in N‐stearoyl‐containing NAPE species. Thus, the percentage of the anandamide precursor fell from 1.1 to 0.5 mol %. In contrast, administration of (+)MK‐801 did not alter cortical NAPE levels. Concussion head trauma resulted in a similar but less pronounced upregulation of NAPE levels at both 4 and 24 h as compared to NMDA injections. Increased levels of NAPE 24 h post‐trauma possibly reflect that necrosis is still ongoing at this time point. Consequently, our data suggest that excitotoxic necrotic mechanisms of neurodegeneration, as opposed to apoptotic neurodegeneration, have a profound effect on in vivo NAE precursor homeostasis.
Molecular cloning and functional characterization of a novel delayed rectifier potassium channel from channel catfish (Ictalurus punctatus): expression in taste buds
Authors: Kang Jiesheng , Teeter John H. , Brazier Stephen P. , Nguyen Nguyen D. , Chang Christine C. , Puchalski Ralph B. 
Published: March 2003

The gustatory system of channel catfish is widely studied for its sensitivity to amino acids. As a first step in identifying the molecular components that play a role in taste transduction in catfish, we cloned the full‐length cDNA for Kv2‐catfish, a novel K+ channel that is expressed in taste buds. The deduced amino acid sequence is 816 residues, and shares a 56–59% sequence identity with Kv2.1 and Kv2.2, the other members of the vertebrate Kv2 subfamily of voltage‐gated K+ channels. The Kv2‐catfish RNA was expressed in taste buds, brain, skeletal muscle, kidney, intestine and gills, and its gene is represented as a single copy in the catfish genome. Recombinant channels expressed in Xenopus oocytes were selective for K+, and were inhibited by tetraethylammonium applied to the extracellular side of the membrane during two‐electrode voltage clamp analysis with a 50% inhibitory constant of 6.1 mm. The channels showed voltage‐dependent activation, and did not inactivate within 200 ms. Functionally, Kv2‐catfish is a voltage‐gated, delayed rectifier K+ channel, and its primary structure is the most divergent sequence identified among the vertebrate members of the Kv2 subfamily of K+ channels, being related equally well to Kv2.1 and Kv2.2.
The role of conserved tryptophan and acidic residues in the human dopamine transporter as characterized by site‐directed mutagenesis
Authors: Chen Nianhang , Vaughan Roxanne A. , Reith Maarten E. A. 
Published: March 2003

The human dopamine (DA) transporter (hDAT) contains multiple tryptophans and acidic residues that are completely or highly conserved among Na+/Cl−‐dependent transporters. We have explored the roles of these residues using non‐conservative substitution. Four of 17 mutants (E117Q, W132L, W177L and W184L) lacked plasma membrane immunostaining and were not functional. Both DA uptake and cocaine analog (i.e. 2β‐carbomethoxy‐3β‐(4‐fluorophenyl)tropane, CFT) binding were abolished in W63L and severely damaged in W311L. Four of five aspartate mutations (D68N, D313N, D345N and D436N) shifted the relative selectivity of the hDAT for cocaine analogs and DA by 10–24‐fold. In particular, mutation of D345 in the third intracellular loop still allowed considerable [3H]DA uptake, but caused undetectable [3H]CFT binding. Upon anti‐C‐terminal‐hDAT immunoblotting, D345N appeared as broad bands of 66–97 kDa, but this band could not be photoaffinity labeled with cocaine analog [125I]‐3β‐(p‐chlorophenyl)tropane‐2β‐carboxylic acid ([125I]RTI‐82). Unexpectedly, in this mutant, cocaine‐like drugs remained potent inhibitors of [3H]DA uptake. CFT solely raised the Km of [3H]DA uptake in wild‐type hDAT, but increased Km and decreased Vmax in D345N, suggesting different mechanisms of inhibition. The data taken together indicate that mutation of conserved tryptophans or acidic residues in the hDAT greatly impacts ligand recognition and substrate transport. Additionally, binding of cocaine to the transporter may not be the only way by which cocaine analogs inhibit DA uptake.
The olfactory G protein Gαolf possesses a lower GDP‐affinity and deactivates more rapidly than Gsαshort: consequences for receptor‐coupling and adenylyl cyclase activation
Authors: Liu Hui‐Yu , Wenzel‐Seifert Katharina , Seifert Roland 
Published: March 2003

The olfactory G protein Gαolf differs from the short splice variant of Gsα (GsαS) in 80 amino acids, but little is known about biochemical differences between Gαolf and GsαS. We addressed this question by analyzing fusion proteins of the β2‐adrenoceptor (β2AR) and Gαolf and GsαS, respectively, using Sf9 insect cells as expression system. The fusion ensured defined receptor/G protein stoichiometry and efficient coupling. High‐affinity agonist binding studies showed that Gαolf possesses a lower GDP‐affinity than GsαS As a result, the agonist‐free β2AR and the β2AR occupied by partial agonists were more efficient at promoting GDP‐dissociation from Gαolf than from GsαS a assessed by guanosine 5’‐O‐(3‐thiotriphosphate) binding, adenylyl cyclase (AC) activity and GTP hydrolysis. Basal AC activity in the absence of GTP was almost sixfold lower in membranes expressing β2AR‐Gαolf than in membranes expressing β2AR‐GsαS at similar levels, reflecting the lower abundance of Gαolf‐GDP relative to GsαS‐GDP. The maximum agonist‐stimulated AC activity with β2AR‐GsαS was more than twofold higher than with β2AR‐Gαolf, but the relative agonist‐stimulation of AC with β2AR‐Gαolf was much greater than with β2AR‐GsαS. The difference in maximum AC activity can be explained by more rapid deactivation of Gαolf‐GTP by GTP hydrolysis and GTP dissociation relative to GsαS‐GTP. Taken together, there are biochemical differences between Gαolf and GsαS, supporting different roles of these G proteins in vivo.
Rapid induction and Ca2+ influx‐mediated suppression of vitamin D3 up‐regulated protein 1 (VDUP1) mRNA in cerebellar granule neurons undergoing apoptosis
Authors: Saitoh Tatsuya , Tanaka Shuuitsu , Koike Tatsuro 
Published: March 2003

Cerebellar granule neurons (CGNs) grown under depolarizing conditions with high K+ (HK; 30 mm) undergo apoptosis following replacement of HK by physiological K+ (5.4 mm). Differential display analysis identified eight genes up‐regulated in this paradigm of apoptosis. Vitamin D3 up‐regulated protein 1 (VDUP1) mRNA was markedly up‐regulated as early as 2 h following HK withdrawal. VDUP1 mRNA was up‐regulated in other paradigms of neuronal apoptosis as well both in vitro and in vivo. HK effectively suppressed the up‐regulation of VDUP1 mRNA in CGNs undergoing apoptosis via Ca2+ influx through voltage‐dependent L‐type Ca2+ channels, which did not require de novo protein synthesis. The up‐regulation occurred in parallel with that of the c‐jun transcript and c‐jun protein phosphorylation. Moreover, SB203580, p38 mitogen‐activated protein kinase inhibitor, suppressed up‐regulation of both c‐jun and VDUP1 mRNAs, and c‐jun phosphorylation in CGNs undergoing apoptosis. IGF‐1, one of the neuroprotective agents for CGNs, also inhibited VDUP1 mRNA up‐regulation through a phosphoinositide 3 kinase‐dependent pathway. These results suggest that the VDUP1 gene is a novel member of early response genes in neuronal apoptosis whose expression is directly regulated by Ca2+ influx and coordinately regulated with the transcription factor c‐jun in CGNs.
In vivo effects of adenosine A2 receptor agonist and antagonist on neuronal and astrocytic intermediary metabolism studied with ex vivo13C MR spectroscopy
Authors: Hammer Janniche , Qu Hong , Håberg Asta , Sonnewald Ursula 
Published: March 2003

The effect of adenosine A2 receptor agonist 2‐[p‐(2‐carboxyethyl)phenylethylamino]‐5′‐ethylcarboxamidoadenosine (CGS 21680) and antagonist 3,7‐dimethyl‐1‐propargylxanthine (DMPX) on [1‐13C]glucose and [1,2‐13C]acetate metabolism was studied in rats by 13C magnetic resonance (MR) spectroscopy and HPLC. In the cortex a significant reduction was observed in the amounts of [2‐13C]GABA and [3‐13C]aspartate from [1‐13C]glucose in CGS 21680. In the subcortex the concentration of labelled [4‐13C]glutamate was increased in both treatment groups. The amounts of [2 + 3‐13C]succinate and [3‐13C]lactate were increased in the CGS 21680 group compared to control, and the DMPX group showed an increase in the total amount of [6‐13C]N‐acetyl aspartate compared to control in the subcortex. Astrocyte metabolism was only affected in the cortex as shown by a decrease in the pyruvate carboxylase/pyruvate dehydrognase ratio in glutamate and glutamine in the treatment groups. Labelling from [1,2‐13C]acetate was not much affected by CGS 21680 or DMPX. However, the amount of [1,2‐13C]acetate in cortex and subcortex was reduced in the DMPX group. In the cortex a reduction in the labelling of [3‐13C]GABA in the DMPX group compared to control and an increase in the total amount of taurine in both treatment groups was detected. The present study shows that A2 receptor agonist and antagonist have similar effects; however, in cortex GABAergic neurones and astrocytes were affected in contrast to subcortex, where glutamatergic neurones showed the greatest changes.
Enhanced hippocampal F2‐isoprostane formation following kainate‐induced seizures
Authors: Patel Manisha , Liang Li‐Ping , Roberts II L. Jackson 
Published: March 2003

We attempted to obtain evidence for the occurrence of oxidant injury following seizure activity by measuring hippocampal F2‐isoprostanes (F2‐IsoPs), a reliable marker of free radical‐induced lipid peroxidation. Formation of F2‐IsoPs esterified in hippocampal phospholipids was correlated with hippocampal neuronal loss and mitochondrial aconitase inactivation, a marker of superoxide production in the kainate model. F2‐IsoPs were measured in microdissected hippocampal CA1, CA3 and dentate gyrus (DG) regions at various times following kainate administration. Kainate produced a large increase in F2‐IsoP levels in the highly vulnerable CA3 region 16 h post injection. The CA1 region showed small, but statistically insignificant increases in F2‐IsoP levels. Interestingly, the DG, a region resistant to kainate‐induced neuronal death also showed marked (2.5–5‐fold) increases in F2‐IsoP levels 8, 16, and 24 h post injection. The increases in F2‐Isop levels in CA3 and DG were accompanied by inactivation of mitochondrial aconitase in these regions. This marked subregion‐specific increase in F2‐Isop following kainate administration suggests that oxidative lipid damage results from seizure activity and may play an important role in seizure‐induced death of vulnerable neurons.
Theory relatingin vitroandin vivomicrodialysis with one or two probes
Authors: Chen Kevin C. , Höistad Malin , Kehr Jan , Fuxe Kjell , Nicholson Charles 
Published: March 2003

AbstractIn this paper, we further develop the general theory of microdialysis by extending the linear model of Bungayet al. to provide a theoretical basis forin vitroandin vivomicrodialysis. Specifically, we considered the effect of active clearance processes onin vivomicrodialysis, and thereby elaborated the theory of Benvenisteet al. to endogenous compounds. We examined the use of steady state tissue diffusion resistance with negligible clearance processes to interpret microdialysis data. The influence of the tissue properties on thein vitroandin vivorecoveries in dual‐probe microdialysis was analyzed and we simulated the effect of the operating parameters on dual probe microdialysis performance. We estimated that the minimum clearance rate constant detectable by microdialysis in a quasi‐steady state is about 5.5 × 10−5s−1. This minimum rate constant establishes a criterion, below which inhibition of the active clearance processes does not show detectable influences on the microdialysis extraction efficiency.
5‐S‐Cysteinyl‐conjugates of catecholamines induce cell damage, extensive DNA base modification and increases in caspase‐3 activity in neurons
Authors: Spencer Jeremy P. E. , Whiteman Matthew , Jenner Peter , Halliwell Barry 
Published: March 2003

AbstractA decrease in reduced glutathione levels in dopamine containing nigral cells in Parkinson's disease may result from the formation of cysteinyl‐adducts of catecholamines, which in turn exert toxicity on nigral cells. We show that exposure of neurons (CSM 14.1) to 5‐S‐cysteinyl conjugates of dopamine,l‐DOPA, DOPAC or DHMA causes neuronal damage, increases in oxidative DNA base modification and an elevation of caspase‐3 activity in cells. Damage to neurons was apparent 12–48 h of post‐exposure and there were increases in caspase‐3 activity in neurons after 6 h. These changes were paralleled by large increases in pyrimidine and purine base oxidation products, such as 8‐OH‐guanine suggesting that 5‐S‐cysteinyl conjugates of catecholamines are capable of diffusing into cells and stimulating the formation of reactive oxygen species (ROS), which may then lead to a mechanism of cell damage involving caspase‐3. Indeed, intracellular ROS were observed to rise sharply on exposure to the conjugates. These results suggest one mechanism by which oxidative stress may occur in the substantia nigra in Parkinson's disease.
Desensitization of pigment granule aggregation in Xenopus leavis melanophores: melatonin degradation rather than receptor down‐regulation is responsible
Authors: Teh Muy‐Teck , Sugden David 
Published: March 2003

Abstract Xenopus laevis melanophores express a high density (Bmax 1224 fmol/mg protein) of high‐affinity (Kd 37 pm) cell membrane melatonin receptors. Treatment of melanophores with melatonin resulted in a loss of membrane melatonin receptors reaching a maximum (∼60%) by 6 h. In addition to receptor loss, a decline in the potency of melatonin to produce pigment aggregation was observed on prolonged treatment. However, the loss of potency (3.8‐fold in 24 h and 162‐fold in 96 h) was much slower than loss of receptors, and was completely prevented by inclusion of eserine (100 µm), an inhibitor of melatonin deacetylation in the culture medium. Incubation of melanophores with [3H]‐melatonin showed that eserine prevented metabolism of melatonin to 5‐methoxytryptamine. These results indicate that although receptor density does decline on prolonged treatment, this is not responsible for the diminishing melatonin potency, which is entirely due to degradation of melatonin by deacetylation and subsequent deamination in melanophores.
Blockade of cannabinoid CB1 receptor function protects against in vivo disseminating brain damage following NMDA‐induced excitotoxicity
Authors: Hansen Henrik H. , Azcoitia Iñigo , Pons Sebastián , Romero Julián , García‐Segura Luis Miguel , Ramos José Antonio , Hansen Harald S. , Fernández‐Ruiz Javier 
Published: March 2003

AbstractThe ability of cannabinoid CB1 receptors to influence glutamatergic excitatory neurotransmission has fueled interest in how these receptors and their endogenous ligands may interact in conditions of excitotoxic insults. The present study characterized the impact of stimulated and inhibited CB1 receptor function on NMDA‐induced excitotoxicity. Neonatal (6‐day‐old) rat pups received a systemic injection of a mixed CB1/CB2 receptor agonist (WIN55,212–2) or their respective antagonists (SR141716A for CB1 and SR144528 for CB2) prior to an unilateral intrastriatal microinjection of NMDA. The NMDA‐induced excitotoxic damage in the ipsilateral forebrain was not influenced by agonist‐stimulated CB1 receptor function. In contrast, blockade of CB1, but not CB2, receptor activity evoked a robust neuroprotective response by reducing the infarct area and the number of cortical degenerating neurons. These results suggest a critical involvement of CB1 receptor tonus on neuronal survival following NMDA receptor‐induced excitotoxicity in vivo.