bluuebunny/crossref_metadata_2025 huggingface dataset:
The spatial and temporal pattern of fatty acid amide hydrolase expression in rat hippocampus during postnatal development
Authors: Morozov Yury M. , Ben‐Ari Yezekiel , Freund Tamas F.
Published: July 2004

GABAergic synaptic transmission is efficiently controlled by endogenous cannabinoids in cortical structures. Fatty acid amide hydrolase (FAAH) is one of the metabolizing enzymes of endocannabinoids in the brain. In this study we investigated the cellular and subcellular distribution of FAAH at various timepoints during the first postnatal weeks, when GABA is still depolarizing, and plays a crucial role in network events. FAAH immunoreactivity is strong in the CA3 region already at postnatal day 0 (P0), but in CA1 only after P8. During this period, FAAH levels in hilar mossy cells decrease and in granule cells slowly increase. Pyramidal cells express FAAH first in the soma and proximal dendrites, and gradually in more distal segments, reaching adult levels in the most distal dendrites only at P22. Transient expression of FAAH was found in a small number of stratum radiatum cells that may be interneurons and in ependymal cells at the border of the alveus and corpus callosum between P2 and P8. At the ultrastructural level, FAAH distribution at all ages was very similar to the adult pattern, i.e. it was largely associated with the membrane of cytoplasmic vesicles, mitochondria and endoplasmic reticulum. During postnatal development of the hippocampus, the spatio‐temporal expression of FAAH correlates well with the general pattern of neuronal maturation, but not with the arrival of afferent pathways, which suggests that FAAH – and its major endocannabinoid substrate, anandamide – is unlikely to be involved in the presynaptic control of neurotransmission. Instead, FAAH may subserve general roles as the inactivating enzyme for many fatty acid amides, in addition to anandamide.
Stabilization of thalamo‐cortical long‐term potentiation by the amygdala: cholinergic and transcription‐dependent mechanisms
Authors: Dringenberg Hans C. , Kuo Min‐Ching , Tomaszek Summer
Published: July 2004

Synaptic potentiation allows neurons to enhance excitability and store information for extended time periods. We examined the role of the amygdaloid complex, known to facilitate long‐term memory encoding, to influence synaptic strength at thalamo‐cortical synapses. In urethane‐anaesthetized rats, theta‐burst stimulation of the dorsal lateral geniculate nucleus of the thalamus induced early phase (1–2 h) long‐term potentiation (LTP) of the field postsynaptic potential (fPSP) recorded in the ipsilateral primary visual cortex. Electrical stimulation (100 Hz) of the amygdala 5 min after thalamic stimulation converted early phase LTP to stable late‐phase (> 4 h) LTP. This effect was not correlated with the degree of electrocorticographic activation of V1 induced by amygdala stimulation. Amygdala stimulation without thalamic theta‐burst stimulation did not change thalamo‐cortical fPSPs. The centrally acting cholinergic‐muscarinic receptor antagonist scopolamine (1 mg/kg, i.p.), but not peripherally acting methyl‐scopolamine, completely blocked the amygdala‐induced conversion of early to late‐phase thalamo‐cortical LTP. Further, ventricular application of the transcription inhibitor anisomycin (250 µg) reduced amygdala‐induced late‐phase LTP induction. These results demonstrate that the amygdaloid complex transforms time‐limited synaptic enhancement of thalamo‐cortical transmission into long lasting increases in synaptic strength. These processes are mediated, at least in part, by cholinergic and transcription‐dependent mechanisms. These amygdaloid‐induced effects provide a potential mechanism underlying long‐term enhancement of sensory transmission and information encoding in thalamo‐cortical networks.
THE INAUGURAL NOEL BUTLIN LECTURE: WORLD FACTOR MIGRATIONS AND DEMOGRAPHIC TRANSITIONS
Authors: Williamson Jeffrey G.
Published: July 2004

This lecture explores the connection between demographic transitions, mass migrations and international capital flows. It reviews how demographic transitions influence the size of age cohorts, and then how these changes in age distribution influence excess demands in receiving regions and excess supplies in sending regions. The lecture offers four examples – two from the first global century and two from the second global century – where shocks generated by demographic transitions have had an enormous impact on factor flows: European mass migrations to the New World before 1914; African mass migrations to the OECD over the past two decades; British capital export to the New World before 1914; and capital flows across East Asian borders after 1950 and before the melt down of the 1990s. The lecture concludes with an assessment of the demographic contribution to the East Asian miracle (and slowdown) over the past half century.
‘MUTTON DRESSED AS LAMB?’ THE MISREPRESENTATION OF AUSTRALIAN AND NEW ZEALAND MEAT IN THE BRITISH MARKET, c. 1890–1914
Authors: Higgins David M.
Published: July 2004

This  article  examines  the  misrepresentation  of  Australasian  meat in Britain, 1890–1914. Using contemporary official analyses of this practice, we investigate the alleged economic consequences for Australasian and British farmers and British consumers and discuss evidence of the extent of this misrepresentation. The need to secure ‘honest trade’ by compulsory marking of imported meat was the principal recommendation of several official enquiries. However, support for the legislative measures proposed to eradicate misrepresentation was far from unanimous. Overall, the evidence suggests that misrepresentation was not as serious in extent or consequence, as some contemporaries feared.
MAKING ARCHIVAL CHOICES FOR BUSINESS HISTORY
Authors: Ellen Jane , Hart Trevor , Piggott Michael , Merrett David
Published: July 2004

To become more proactive in their acquisition of the archives of Victorian business, the University of Melbourne Archives adapted a methodology pioneered by the Minnesota Historical Society. This enabled them to establish criteria to identify industrial sectors, and target  specific  companies  within  them,  which  match  the  strengths of the Victorian economy; and to determine the type of records required to adequately document both company and sector.
Debt, Growth and Budgetary Regimes
Authors: Ghosh Sugata , Mourmouras Iannis A.
Published: July 2004

Within the Barro (1990) model of productive public services, but with the inclusion of public debt, we derive and characterize on the balanced growth path, a set of welfare‐maximizing fiscal rules under two budgetary regimes – one with only the standard dynamic government budget constraint, and the other involving the golden rule of public finance. We demonstrate analytically that the optimal fiscal policy differs in the two budgetary regimes considered. We also analyse two cases within the second regime: one, where the ratio of current spending to tax revenues is parametrically given, and another, where this ratio is optimally chosen by the government.
Inflation, Shadow Prices and the EMU: Evidence From Greece
Authors: Tsionas Efthymios G. , Christopoulos Dimitris K.
Published: July 2004

The paper examines whether inflation systematically distorts the informational content of price signals. A shadow cost function is specified, and the deviation of shadow from actual prices is modeled as a function of the level of economy‐wide inflation, as well as other conditioning variables like budget deficits and changes in inflation rate. It is found that inflation is associated with significant allocative costs in most Greek manufacturing sectors. Measures of cost gains resulting from Greece's convergence towards the EMU are provided and the policy implications are explored.
Folk Theorem For Bilateral Bargaining with Vector Endowments
Authors: Horniacek Milan
Published: July 2004

We analyse a bargaining game of two players on the division of the sum of their vector endowments, with alternating proposals and discounting of single period utilities. The pair of endowments is not weakly Pareto‐efficient. Until they reach an agreement, each of the parties can withdraw from bargaining and keep their endowments. Any strictly individually rational division of the sum of endowments can emerge in some subgame perfect equilibrium if discount factors are close enough to one. Each subgame perfect equilibrium, in which the parties’ decisions do not depend on past rejected proposals, leads to a weakly Pareto‐efficient agreement in the first period.
Fitting in and Multi‐tasking: Dutch Farm Women's Strategies in Rural Entrepreneurship
Authors: Bock Bettina B.
Published: July 2004

All over Europe more and more farm families start new income generating activities on and off the farm to supplement the decreasing income from primary productions. Farmwomen play an important role in these strategies but are at the same time perceived as less professional entrepreneurs compared to men. This is due to women's cautious and small‐scaled approach to entrepreneurship, which is in its turn explained by women's lack of resources. This article follows another line of argument and departs from the question why women themselves choose to behave differently and prefer certain behaviour modes above others. The article is based on two research projects, which took place in the Netherlands during 1995–2001. The first research focused on how and why farmwomen started new economic activities on and off the farm. It shows that Dutch farmwomen share a specific approach to rural entrepreneurship and paid labour, which is characterised by fitting in and multi‐tasking. Women add the new activities to their regular tasks and fit them into the already existing working scheme because they want to make sure that neither family nor farm is troubled by their initiatives. The second project focused on the development of new on farm activities over the course of time and followed five female rural entrepreneurs from 1995 to 2001. It demonstrates that women may change their approach and expand their business when they experience that work and care may be successfully combined and that their new business is rewarding financially as well as emotionally. Understanding women's specific approach to entrepreneurship is important in order to more effectively support them. So far, rural development policies are of little help to women as they usually promote a type of entrepreneur and an approach to entrepreneurship most common among men.
For a ‘Piece of Bread’? Interpreting Sustainable Development through Agritourism in Southern Tuscany
Authors: Sonnino Roberta
Published: July 2004

Under global conditions that threaten the viability of rural economies and the farm sector, Italian legislation supports both through agritourism, a form of rural tourism conceived to diversify and complement the economic activities of individual farms. In theory, agritourism is a sustainable strategy: in its stated objectives, it promotes the conservation of a broadly conceived rural environment through its socioeconomic development. Building upon recent calls for assessments of sustainability that are relative to local environments, this paper analyses the relationship between the assumptions of a political scheme that attempts to sustain the rural environment and the perceptions and practices of those who live in that environment. Data collected in two different sites of southern Tuscany through participant observation and in‐depth interviews show that different structural conditions and differing cultural values make agritourism responsive to the wants and needs of just one segment of the local farming population. In advocating rural development strategies that take into account pre‐existing socioeconomic inequalities and varieties in farmers' environmental worldviews, this case study challenges the efficacy of global paradigms and emphasizes the role of empirical research in devising sustainable policies.
The Trouble with ‘Organic Lite’ in California: a Rejoinder to the ‘Conventionalisation’ Debate
Authors: Guthman Julie
Published: July 2004

Based on a comprehensive study of the California organic sector, this article responds to the conventionalization debate on organic farming that surfaced after the publication of Buck et al. in 1997 in this journal. First, it addresses the place of California within the international organic sector, justifying its importance as a case study. As an empirical point, it documents the form and extent of agribusiness involvement in California's organic sector and provides place‐specific explanations as to how it articulated with the previously existing organic sector. It also considers how agribusiness has influenced organic production, in rule‐setting, inter‐sectoral dynamics, and agronomic practices. The argument is that agribusiness involvement does more than create a soft path of sustainability ‐ or ‘organic lite’; the conditions set by processes of agro‐industrialization undermine the ability of even the most committed producers to practice a truly alternative form of organic farming. This trajectory is not inevitable, however, and largely turns on the sort of state support given to organic farming.
The Chestnut Economy: The Praxis of Neo‐Peasantry in Rural France
Authors: Willis Scott , Campbell Hugh
Published: July 2004

This article presents the results of a study of an informal economy within le Parc national des Cévennes and observes the way in which diverse groups have re‐inhabited and re‐inscribed a previously abandoned peasant landscape. This study is theoretically interpreted in the light of recent theorization of globalisation, neo‐liberalism, the consumption of landscape, the variability and agency which constructs space, and the importance of regionalisation as a dynamic in late capitalism. These issues of international interest operate in a French context alongside both the activist heritage of the Paris Spring and the broader cultural dynamic of patrimonialisation in rural France. The discussion traces the emergence of a localised praxis mobilised by ex‐urban activists. This praxis is centred on the development of a vibrant informal economy ‐ the ‘chestnut economy’. This was a highly contested process, with a collision (and later collusion) of interests being negotiated between ex‐urban activists, absentee owners of property and the residual local population. It is in outlining the terrain of contestation between the main communities of interest, and their eventual accommodation through the activities of the ‘chestnut economy’, that the effectiveness of a praxis of neo‐peasantry can be observed.
The New Common Sense of Education: Advocacy Research versus Academic Authority
Authors: Shaker Paul , Heilman Elizabeth E.
Published: July 2004

Current education policy is increasingly controlled by partisan politicians and the corporate interests that speak through them. Attacking American education and blaming economic troubles on failing schools and low standardized test scores coalesces the rhetoric of the right and draws attention away from fundamental social and economic problems. Add to this political opportunity the economic fact that attacking K–12 education leaves this market of $732 billion vulnerable to development by corporate America. Though such attacks have been with us since A Nation at Risk, an increasingly broad array of cultural and institutional forces are at work creating a new “common sense” of education that maligns or manipulates the corpus of educational research and attacks promising practices and reforms. In addition, a new type of education scholarship has emerged that is delivered in alternative ways, funded through unorthodox sources, motivated by nonacademic purposes, and supported through direct access to media and political organizations, including the federal government. This article examines the details of the new commonsense policy and rhetoric and considers what is being lost and what educators need to do to restore to public education its position of civic and moral leadership in our society.
Predicting growth of nonword reading and letter‐sound knowledge following rime‐ and phoneme‐based teaching
Authors: Savage Robert , Carless Sue
Published: July 2004

The present study sought to extend a recent study by Savage, Carless and Stuart, by looking at the pre‐test phonological skills that predicted improvements in letter‐sound knowledge and nonword reading. Results showed overall that phoneme manipulation predicted improvements in nonword reading and letter‐sound knowledge even when pre‐test scores on the respective dependent variables were controlled. Pre‐test letter‐sound knowledge was an independent predictor of nonsense word reading. Overall, onset‐rime manipulation did not add to the prediction of outcome. Onset‐rime manipulation predicted decoding improvements in a subgroup where children were exposed to both rime and phoneme‐based teaching.
Letter knowledge precipitates phoneme segmentation, but not phoneme invariance
Authors: Carroll Julia M.
Published: July 2004

There is a wealth of evidence linking letter knowledge and phoneme awareness, but there is little research examining the nature of this relationship. This article aims to elucidate this relationship by considering the links between letter knowledge and two sub‐skills of phoneme awareness: phoneme segmentation and phoneme invariance. Two studies are reported. The first study consisted of an eight‐month longitudinal study with 56 pre‐literate children. No child within this group was successful on any phoneme awareness task unless they knew at least one letter. Letter knowledge was also a significant predictor of later phoneme completion and deletion. The hypothesis that letter knowledge is an important precursor for phoneme awareness was then investigated in a small‐scale intervention study with ten children. These children were taught letters and their phoneme awareness was monitored. It was found that letter knowledge was specifically related to the development of phoneme segmentation in pre‐literate children. Possible reasons for this finding are discussed.
An investigation of Grade 5 children's knowledge of the doubling rule in spelling
Authors: Steffler Dorothy J.
Published: July 2004

The goal of this study was to investigate Grade 5 children's knowledge of a common word pattern in English, to double the final consonant of a one‐syllable word when adding –ed. Significant correlations were found between –edspelling and general spelling ability, as well as correct pronunciation of –edwords in isolated word reading and spelling. The correlation between –edspelling and –edword reading (r=0.31) is lower than one would expect to find in general spelling and reading ability. Individual interviews were conducted to assess children's explicit awareness of the doubling rule, followed by a measure of consistency in spelling a selected number of –edwords. Performance on an artificial grammar task indicated a correlation between implicit learning of nonsense letter strings and spelling ability. Overall results point to the unstable nature of children's knowledge of thedoubling rule. Implications for instruction are discussed.
The effect of orthographic depth on reliance upon semantic context for oral reading in English and Hebrew
Authors: Benuck Marni B. , Peverly Stephen T.
Published: July 2004

This paper examines the relationship between orthographic depth and reliance upon context for oral reading in English and Hebrew. Research on context effects in English has indicated that the decoding ability of adequate readers is only minimally affected by context. The effect of context may be greater in Hebrew because of its deeper orthography – context may help readers phonologically and semantically disambiguate words whose letters do not provide enough information for grapheme‐to‐phoneme conversion. It is hypothesised that bilingual English‐Hebrew participants would rely more upon context for oral reading of Hebrew than English and that in Hebrew, reading words which are more phonologically ambiguous (high degree of freedom words) would be more affected by context than reading of words which are less phonologically ambiguous (low degree of freedom words). Results support both hypotheses. The findings are consistent with the Orthographic Depth Hypothesis.
Verbal memory and phonological processing in dyslexia
Authors: Tijms Jurgen
Published: July 2004

This study examines whether two frequently reported causes of dyslexia, phonological processing problems and verbal memory impairments, represent a double‐deficit or whether they are two expressions of the same deficit. Two‐hundred‐and‐sixty‐seven Dutch children aged 10–14 with dyslexia completed a list‐learning task and several phonological tasks, together with a number of reading and spelling tests. The results indicate that phonological deficits and verbal memory impairments in dyslexia stem from the same root, which seemingly reflects an inaccurate encoding of the phonological characteristics of verbal information. This phonological encoding deficit is a negative predictor for both the reading and spelling skills of dyslexic children.
From biography to history: writing the modern British monarchy
Authors: Cannadine David
Published: July 2004

This article traces the development of biographical and historical writing about the British monarchy from the ‘golden age’ of Elizabeth I to the House of Windsor. It examines the differences in approach over the past two centuries, in particular, from the uncritical biographies of the Victorian period to the current unregulated flood of material, authorized and unauthorized. Such an analysis goes beyond the history of dynasties and individuals and becomes a history of society as reflected in the changing experiences of the British royal family.
The household and entourage of Charles I of Anjou, king of the Regno, 1266–85
Authors: Dunbabin Jean H.
Published: July 2004

This article attempts to reconstitute from the scrappy surviving records Charles I's household and court. For a conqueror, the choice of companions could have serious political implications. While Charles's immediate domestic circle was French in origin and organized on the example of Louis IX's household, he deliberately encouraged and paid for the attendance of men from Provence and the Regno, both in his travelling entourage and at his great court appearances at liturgical feasts. Beyond these intimates, he accepted into his fidelity, and therefore into his broader court circle, a wide range of talented individuals from all parts of his ‘empire’.
Brain to blood efflux transport of adenosine: blood–brain barrier studies in the rat
Authors: Isakovic Aleksandra J. , Abbott N. Joan , Redzic Zoran B.
Published: July 2004

The blood–brain barrier (BBB) efflux transport of [14C] adenosine was studied using the brain efflux index (BEI) technique. BEI increased linearly over the first 2 min after injection, with deviation from linearity thereafter; 90.12 ± 1.5% of the injected [14C] radioactivity remained within the brain after 20 min. The remaining tracer appears to be mainly intracellular, trapped by phosphorylation, as an almost linear increase of BEI over 20 min was observed after intracerebral injection of [14C] adenosine together with 5‐iodo tubercidin. The BBB efflux clearance of [14C] radioactivity was estimated to be 27.62 ± 5.2 µL/min/g, almost threefold higher than the BBB influx clearance estimated by the brain uptake index technique. High‐performance liquid chromatography (HPLC) analysis of blood plasma collected from the jugular vein after the intracerebral injection revealed metabolic breakdown of [14C] adenosine into nucleobases. The BBB efflux transport was saturable with apparent Km = 13.22 ± 1.75 µm and Vmax = 621.07 ± 71.22 pmole/min/g, which indicated that BBB efflux in vivo is 6.2–12p mole/min/g, negligible when compared to the reported rate of adenosine uptake into neurones/glia. However, these kinetic parameters also suggest that under conditions of elevated ISF adenosine in hypoxia/ischaemia, BBB efflux transport could increase up to 25% of the uptake into neurones/glia and become an important mechanism to oppose the rise in ISF concentration. HPLC‐fluorometry detected 93.6 ± 5.25 nm of adenosine in rat plasma, which is 17‐ to 220‐fold lower than the reported Km of adenosine BBB influx in rat. Together with the observed rapid degradation inside endothelial cells, this indicated negligible BBB influx of intact adenosine under resting conditions. Cross‐inhibition studies showed that unlabelled inosine, adenine and hypoxanthine caused a decrease in BBB efflux of [14C] radioactivity in a concentration‐dependent manner, with Ki of 16.7 ± 4.88, 65.1 ± 14.1 and 71.1 ± 16.9 µm, respectively. This could be due to either competition of unlabelled molecules with [14C] adenosine or competition with its metabolites hypoxanthine and adenine for the same transport sites.
Phosphorylation of microtubule‐associated protein tau by isoforms of c‐Jun N‐terminal kinase (JNK)
Authors: Yoshida Hirotaka , Hastie C. James , McLauchlan Hilary , Cohen Philip , Goedert Michel
Published: July 2004

Microtubule‐associated protein tau in a hyperphosphorylated state is the major component of the filamentous lesions that define a number of neurodegenerative diseases commonly referred to as tauopathies. Hyperphosphorylation of tau at most sites appears to precede filament assembly. Many of the hyperphosphorylated sites are serine/threonine–proline sequences. Here we show that c‐Jun N‐terminal kinases JNK1, JNK2 and JNK3 phosphorylate tau at many serine/threonine–prolines, as assessed by the generation of the epitopes of phosphorylation‐dependent anti‐tau antibodies. Of the three protein kinases, JNK2 phosphorylated the most sites in tau, followed by JNK3 and JNK1. Phosphorylation by JNK isoforms resulted in a greatly reduced ability of tau to promote microtubule assembly. These findings extend the number of candidate protein kinases for the hyperphosphorylation of tau in Alzheimer's disease and other neurodegenerative disorders.
HIF‐1α reveals a binding activity to the promoter of iNOS gene after permanent middle cerebral artery occlusion
Authors: Matrone C. , Pignataro G. , Molinaro P. , Irace C. , Scorziello A. , Di Renzo G. F. , Annunziato L.
Published: July 2004

Hypoxia inducible factor (HIF‐1)‐1α is a specific, oxygen‐sensitive protein that regulates the activity of HIF‐1, a transcriptional factor that increases after cerebral ischemia and may either promote or prevent neuronal survival. In this study to determine whether the inducible nitric oxide synthase (iNOS) gene containing the sequence of the hypoxia‐responsive enhancer (HRE) was an HIF‐1 target after cerebral ischemia induced by permanent middle cerebral artery occlusion (pMCAO), electrophoretic mobility shift assay (EMSA) and iNOS western blot analysis were performed in the ischemic core, in the area surrounding the infarct and in the hippocampus ipsilateral and contralateral to the lesion. In addition, both HIF‐1α mRNA and protein expression were examined in the ischemic core, in the area surrounding the ischemic core and in the hippocampus ipsilateral to the insult. Our results revealed that pMCAO up‐regulates iNOS protein in the ischemic core, in the area surrounding the ischemic core and in the hippocampus ipsilateral to the lesion, and that the activation of iNOS expression is mediated by HIF‐1. Moreover, HIF‐1α mRNA and protein levels increased in the ischemic core and in the hippocampus ipsilateral to the lesion compared with the levels obtained in the corresponding areas of sham‐operated controls or in the contralateral hemisphere. Particularly in the area surrounding the ischemic core, HIF‐1α protein accumulated during pMCAO although mRNA did not increase. Our study suggests that the activation of HIF‐1 might be involved in the mechanisms whereby iNOS promotes cell survival and/or death after cerebral ischemia.
Stimulus‐dependent regulation and cellular expression of genes encoding neuropeptides, prohormone convertases, α‐amidating enzyme and 7B2 in identified Lymnaea neurons
Authors: Spijker Sabine , Sharp‐Baker Hilary E. , Geraerts Wijnand P. M. , Van Minnen Jan , Smit August B.
Published: July 2004

Synthesis of bioactive peptides is regulated by several post‐translational processing events, including cleavage of peptides from a prohormone, and chemical modifications. Using quantitative in situ hybridization and neuron‐specific macro‐arrays, we first demonstrated cell‐type specific expression levels of transcripts encoding prohormone convertases, peptide α‐amidating enzyme as well as the chaperone 7B2 in Lymnaea neurons. Second, we demonstrated a strict correlation between α‐amidating enzyme and its neuropeptide substrates. However, this strict relationship of gene expression of the three prohormone convertases and types of cleavage site used is not present. Third, we showed by a physiological stimulus, i.e. clean water, which leads to a stereotyped egg‐laying behaviour resulting in successful egg‐mass deposition, the co‐regulated induction of transcript levels of processing enzymes, 7B2, and egg‐laying hormone. These data indicate that (i) these enzymes (and chaperone) are involved in egg‐laying hormone neuropeptide biosynthesis, and (ii) neuropeptide release and transcript levels of both prohormones and processing enzymes are regulated in accordance with physiological demands.
UCH‐L1 aggresome formation in response to proteasome impairment indicates a role in inclusion formation in Parkinson's disease
Authors: Ardley Helen C. , Scott Gina B. , Rose Stephen A. , Tan Nancy G. S. , Robinson Philip A.
Published: July 2004

Aggresomes are associated with many neurodegenerative disorders, including Parkinson's disease, and polyglutamine disorders such as Huntington's disease. These inclusions commonly contain ubiquitylated proteins. The stage at which these proteins are ubiquitylated remains unclear. A malfunction of the ubiquitin/proteasome system (UPS) may be associated with their formation. Conversely, it may reflect an unsuccessful attempt by the cell to remove them. Previously, we demonstrated that overexpression of Parkin, a ubiquitin‐protein ligase associated with autosomal recessive juvenile Parkinsonism, generates aggresome‐like inclusions in UPS compromised cells. Mutations in the de‐ubiquitylating enzyme, UCH‐L1, cause a rare form of Parkinsonism. We now demonstrate that overexpression of UCH‐L1 also forms ribbon‐like aggresomes in response to proteasomal inhibition. Disease‐associated mutations, which affect enzymatic activities, significantly increased the number of inclusions. UCH‐L1 aggresomes co‐localized with ubiquitylated proteins, HSP70, γ‐tubulin and, to a lesser extent, the 20S proteasome and the chaperone BiP. Similar to Parkin inclusions, we found UCH‐L1 aggresomes to be surrounded by a tubulin rather than a vimentin cage‐like structure. Furthermore, UCH‐L1 aggregates with Parkin and α‐synuclein in some, but not all inclusions, suggesting the heterogeneous nature of these inclusion bodies. This study provides additional evidence that aggregation‐prone proteins are likely to recruit UPS components in an attempt to clear proteins from failing proteasomes. Furthermore, UCH‐L1 accumulation is likely to play a pathological role in inclusion formation in Parkinson's disease.
CRF receptor type 1 and 2 expression and anatomical distribution in the rat colon
Authors: Chatzaki Ekaterini , Crowe Paul D. , Wang Lixin , Million Mulugeta , Taché Yvette , Grigoriadis Dimitri E.
Published: July 2004

Corticotropin‐releasing factor (CRF) receptor agonists administered peripherally increase colonic propulsive motility and fecal output in experimental animals. In addition, endogenous CRF‐related peptides are found in the lower gastrointestinal (GI) tissues, suggesting a local expression of CRF receptors. In the present study, we report the expression of both CRF receptor type 1 (CRF1) and 2 (CRF2) in the rat colon at the mRNA and protein levels. For the purpose of receptor protein mapping, a specific antiserum against the C‐terminus of CRF2(2064a‐CRF2) was generated and characterized. This antiserum in conjunction with a selective anti‐CRF1antiserum (4467a‐CRF1) was used in immunofluorescent staining to demonstrate the anatomical distribution of receptor protein expression. Using RT‐PCR for the CRF1and CRF2genes, both receptor gene transcripts were found in RNA isolated from crude colonic samples. CRF1was found in the goblet and stem cells of the colonic crypts and in scattered cells of the surface epithelium and the lamina propria of the proximal colonic mucosa. In addition, double staining against neuron‐specific antigens revealed CRF1expression in the myenteric and submucosal nervous plexus. CRF2expression was localized mainly in the luminal surface of the crypts and in blood vessels of the submucosal layer. These results demonstrate expression of both CRF receptor types in the rat colon and support a role for their involvement in regulating peripheral effects of CRF ligands.
Spinophilin is phosphorylated by Ca2+/calmodulin‐dependent protein kinase II resulting in regulation of its binding to F‐actin
Authors: Grossman Stacie D. , Futter Marie , Snyder Gretchen L. , Allen Patrick B. , Nairn Angus C. , Greengard Paul , Hsieh‐Wilson Linda C.
Published: July 2004

Spinophilin is a protein phosphatase‐1‐ and actin‐binding protein that modulates excitatory synaptic transmission and dendritic spine morphology. We have recently shown that the interaction of spinophilin with the actin cytoskeleton depends upon phosphorylation by protein kinase A. We have now found that spinophilin is phosphorylated by Ca2+/calmodulin‐dependent protein kinase II (CaMKII) in neurons. Ca2+/calmodulin‐dependent protein kinase II, located within the post‐synaptic density of dendritic spines, is known to play a role in synaptic plasticity and is ideally positioned to regulate spinophilin. Using tryptic phosphopeptide mapping, site‐directed mutagenesis and microsequencing analysis, we identified two sites of CaMKII phosphorylation (Ser‐100 and Ser‐116) within the actin‐binding domain of spinophilin. Phosphorylation by CaMKII reduced the affinity of spinophilin for F‐actin. In neurons, phosphorylation at Ser‐100 by CaMKII was Ca2+ dependent and was associated with an enrichment of spinophilin in the synaptic plasma membrane fraction. These results indicate that spinophilin is phosphorylated by multiple kinases in vivo and that differential phosphorylation may target spinophilin to specific locations within dendritic spines.
Somatic and axonal effects of ATP via P2X2 but not P2X7 receptors in rat thoracolumbar sympathetic neurones
Authors: Allgaier C. , Reinhardt R. , Schädlich H. , Rubini P. , Bauer S. , Reichenbach A. , Illes P.
Published: July 2004

Excitatory ATP responses in rat cultured thoracolumbar sympathetic neurones are mediated by somatic P2X2 receptors. The present study investigated a possible role of axonal P2X2 as well as P2X7 receptors on the same preparation. Confocal laser scanning microscopy demonstrated P2X2 and P2X7 immunoreactivity along the axons as well as P2X7 immunoreactivity surrounding the cell nuclei. P2X7 mRNA expression was detected in individual neurones using a single‐cell RT–PCR approach. Adenosine triphosphate (ATP) caused a significant increase in axonal Ca2+ concentration which was dependent on external Ca2+ but insensitive to depletion of the cellular Ca2+ pools by cyclopiazonic acid. Pyridoxal‐phosphate‐6‐azophenyl‐2′,4′‐disulfonate (PPADS; 30 µm) virtually abolished the ATP response, whereas brilliant blue G (0.1 µm), a selective P2X7 receptor antagonist, had no effect. Dibenzoyl‐ATP (BzATP; 100 µm) induced a much smaller increase in axonal [Ca2+] concentration than ATP at equimolar concentrations. The response to BzATP was distinctly reduced by PPADS but not by brilliant blue G. The overall pharmacological profile of the axonal P2X receptors resembled closely that of the somatic P2X2 receptors. In conclusion, the present data suggest the occurrence of axonal excitatory P2X2 receptors in thoracolumbar sympathetic neurones. However, the functional significance of axonal and (peri)‐nuclear P2X7 receptors has still to be proven.
Novel isoforms of tau that lack the microtubule‐binding domain
Authors: Luo Min‐hua , Tse Sze‐Wah , Memmott John , Andreadis Athena
Published: July 2004

Tau is a microtubule‐associated protein (MAP) whose transcript undergoes complex regulated splicing in the mammalian nervous system. Our previous work with exon 6 established that tau shows a unique expression pattern and splicing regulation profile, and that it utilizes alternative splice sites in several human tissues. The mRNAs from these splicing events, if translated, would result in truncated tau variants that lack the microtubule‐binding domain. In this study, we demonstrate that at least one of these tau variants is present as a stable protein in several tissues. The novel isoform shows a localization distinct from that of canonical tau in SH‐SY5Y neuroblastoma cells which stably overexpress it. In both normal and Alzheimer's hippocampus, the novel isoform is found in dentate gyrus granular cells and CA1/CA3 pyramidal cells. However, it does not co‐localize with canonical tau but, rather, partly co‐localizes with MAP2.
Annular α‐synuclein species from purified multiple system atrophy inclusions
Authors: Pountney Dean L. , Lowe Rachel , Quilty Marian , Vickers James C. , Voelcker Nicolas H. , Gai Wei Ping
Published: July 2004

Oligodendroglial cytoplasmic inclusions composed of α‐synuclein filamentous aggregates are the pathological hallmark of multiple system atrophy (MSA). We found that cortical tissue from MSA cases contains increased detergent‐resistant high‐molecular‐weight α‐synuclein species. To analyse these species, we immunopurified α‐synuclein aggregates from pathological samples and examined their ultrastructures using scanning electron and atomic force microscopies. Purified aggregates consisted of bundles of filaments. After treatment with 1% sarcosine or 2% 3‐[(3‐cholamidopropyl) dimethyl‐ammonio]‐1‐propanesulfonate (CHAPS) detergents, we observed frequent 30–50 nm annular particles, probably released from pathological aggregates due to the dissociation of filaments by the detergents. Antibody recognition imaging using a specific anti‐α‐synuclein antibody confirmed that the annular structures were positive for α‐synuclein. In contrast to pathological α‐synuclein, detergent treatment of recombinant α‐synuclein yielded only smaller, 10–18 nm spherical particles. Our results demonstrate that detergent treatment of pathological MSA α‐synuclein aggregates, but not recombinant α‐synuclein, yields discrete α‐synuclein‐positive species with annular morphologies. The ability of the pathological α‐synuclein to form annular aggregates may be an important factor contributing to the toxicity of the protein in disease that may have implications in designing therapeutic strategies aimed at detoxifying α‐synuclein aggregates.
Methane production by microbial mats under low sulphate concentrations
Authors: BEBOUT BRAD M. , HOEHLER TORI M. , THAMDRUP BO , ALBERT DAN , CARPENTER STEVEN P. , HOGAN MARY , TURK KENDRA , DES MARAIS DAVID J.
Published: July 2004

Cyanobacterial mats collected in hypersaline salterns were incubated in a greenhouse under low sulphate concentrations ([]) and examined for their primary productivity and emissions of methane and other major carbon species. Atmospheric greenhouse warming by gases such as carbon dioxide and methane must have been greater during the Archean than today in order to account for a record of moderate to warm palaeoclimates, despite a less luminous early sun. It has been suggested that decreased levels of oxygen and sulphate in Archean oceans could have significantly stimulated microbial methanogenesis relative to present marine rates, with a resultant increase in the relative importance of methane in maintaining the early greenhouse. We maintained modern microbial mats, models of ancient coastal marine communities, in artificial brine mixtures containing both modern [] (c. 70 mm) and ‘Archean’[] (<0.2 mm). At low [], primary production in the mats was essentially unaffected, while rates of sulphate reduction decreased by a factor of three, and methane fluxes increased by up to 10‐fold. However, remineralization by methanogenesis still amounted to less than 0.4% of the total carbon released by the mats. The relatively low efficiency of conversion of photosynthate to methane is suggested to reflect the particular geometry and chemical microenvironment of hypersaline cyanobacterial mats. Therefore, such mats were probably relatively weak net sources of methane throughout their 3.5 Ga history, even during periods of low environmental levels oxygen and sulphate.
Stable carbon isotopes and the metabolism of the terrestrial Devonian organism Spongiophyton
Authors: FLETCHER BENJAMIN J. , BEERLING DAVID J. , CHALONER WILLIAM. G.
Published: July 2004

Devonian fossils of Spongiophyton have been identified as a terrestrial evolutionary intermediate between algae and vascular land plants on the basis of their dichotomously branched, tubular morphology, thick cuticles, and the scattered distribution of surface pores. Our understanding of their physiology is, however, severely limited, but may be increased through the use of stable carbon isotope measurements. One such study led to the hypothesis that Spongiophyton carried a carbon isotope (δ13C) signature characteristic of lichens (Jahren et al., 2003Geology31, 99–102). Here, we outline three difficulties with accepting this idea and report independent isotopic measurements of Spongiophyton fossils from Canada and Ghana. Our results show that the isotopic discrimination of analogous tissues of Spongiophyton, extant lichens, liverworts and mosses are statistically indistinguishable. We suggest therefore that claims to have definitively identified lichen metabolism are premature, and cannot be sustained.
A novel method to assess systolic ventricular function using atrioventricular plane displacement – a study in young healthy males and patients with heart disease
Authors: Carlhäll C. , Hatle L. , Nylander E.
Published: July 2004

Analysis of atrioventricular plane displacement (AVPD) is a well established method for assessment of both systolic and diastolic ventricular function. For several years, AVPD has been a clinical tool and there are many current, as well as potential, areas of application. However, clinical work has shown that the traditional method for evaluation of systolic ventricular function, called total AVPD, does not temporally reflect true systole. Systolic AVPD is a new approach for measuring AVPD to assess ventricular systolic function. We wished to apply this new model in healthy subjects and in patients with different common heart diseases. Twenty‐eight young healthy males and 30 patients (aortic stenosis, left sided regurgitant lesions, postmyocardial infarction) were enrolled. AVPD was obtained at the four standard sites by M‐mode. Total AVPD was measured in the conventional way and systolic AVPD by identifying true systole, by means of mitral‐ and aortic valve closure respectively. Ventricular volumes were calculated according to biplane Simpson's rule. The systolic AVPD measurements were significantly lower than the total measurements, at both atrioventricular planes in all groups (P<0·001). This discrepancy was greater at the mitral than at the tricuspid annulus in the patients 24·2% vs. 15·5% (P<0·001), but did not differ in the healthy subjects. At the mitral annulus, this discrepancy also seemed to be more pronounced in the patients than in the healthy subjects 24·2% vs. 10·7%. When assessing ventricular systolic function by AVPD, the conventional method overestimates the amplitude in relation to true systolic function in both patients with heart disease and in young healthy males. Thus, there are uncertainties regarding earlier estimations of AVPD in terms of expression of systolic function and regarding previously presented reference values. We recommend the proposed methodology.
A computerized human reference brain for rCBF/SPET technetium‐99m exametazime (HMPAO) investigation of elderly
Authors: Sparring Björkstén Karin , Ekberg Stefan , Säfström Pia , Dige Niels , Granerus Göran
Published: July 2004

Using the bull's eye approach, a reference brain from the single photon emission tomography (SPET) images of 10 subjects aged 62–81 years with excellent mental and physical health was constructed. SPET images were acquired twice, 1 week apart, using a single detector rotating gamma camera collecting 64 planar images over a 360° orbit. The centre of each transaxial slice was first defined with an automatic edge detecting algorithm applied to an anterior–posterior and a side profile of the brain. Each slice was divided into 40 sectors. Maximum counts/pixel in each sector was picked. The 40 maximum count values from one transaxial slice were allowed to form a horizontal row in a new parametric image on the x‐axis and slice number from the vertex to the basal parts of the brain on the y‐axis. This new image was scaled to a 64 × 16 pixel matrix by interpolation, which meant a normalization of all studies to the same size. The parametric image in each subject was scaled with regard to intensity by a factor calculated by a normalization procedure using the least squares analysis. Mean and SD for each pixel were calculated, thereby constructing a ‘mean parametric image’, and a ‘SD parametric image’. These two images are meant to be used as the reference brain for evaluation of patient studies. This method can be used for objective measurements of diffuse brain changes and for pattern recognition in larger groups of patients. Statistical multifactorial analysis of parameters used for acquisition and data processing is possible.
Blood oxygen transport and endothelial dysfunction in patients with arterial hypertension
Authors: Zinchuk V. V. , Pronko T. P. , Lis M. A.
Published: July 2004

Disturbed nitric oxide (NO) synthesis leads to development of endothelial dysfunction that plays a significant role in the pathogenesis of arterial hypertension. The presence of various compounds of haemoglobin with NO can affect haemoglobin‐oxygen affinity of the whole blood. Methaemoglobin and S‐nitrosohaemoglobin increase it, whereas nitrosyl‐haemoglobin decreases. The aim of this study was to investigate the blood oxygen transport indices and to assess the endothelial function in patients with arterial hypertension. The patients with mild hypertension had a 4·47% increased actual p50 (the blood pO2 corresponding to its 50% oxygen saturation) (P<0·05), a diminished pO2 (P<0·05), and a raised pCO2 (P<0·01) as compared with the controls. The patients with severe hypertension had decreased pO2 and pH, and actual p50 was reduced by 3·03% (P<0·05), which reflects a more pronounced oxyhaemoglobin dissociation curve shift leftwards. These changes can be assessed as a blood oxygen transport decompensation that enhanced tissue hypoxia. The results of our studies indicate that the endothelial dysfunction in patients with arterial hypertension leads to significant impairments in blood oxygen transport indices. The endothelium may be involved in development of the above blood oxygen transport impairments, since only sufficient amounts of NO maintain a normal blood flow and oxygen transport to tissues. The endothelial dysfunction leads to a disturbed production of different haemoglobin NO derivatives, which not only affects NO release at different sites of the arterial bed, but also haemoglobin‐oxygen affinity and optimal blood oxygenation and deoxygenation in capillaries. These data support the notion that endothelial dysfunction may alter haemoglobin‐oxygen affinity and tissue oxygen supply in vivo. Alternation of haemoglobin‐oxygen supply may be involved in the pathogenesis of hypertension.