bluuebunny/crossref_metadata_2025 huggingface dataset:
Prostaglandin E2 production and viability of cells cultured in contact with freshly mixed endodontic materials
Authors: Melegari K. K. , Botero T. M. , Holland G. R.
Published: March 2006

Aim  To determine whether commonly used endodontic sealers could either induce or increase the release of prostaglandin E2 (PGE2) when in contact with cell types found in the periapical tissues.

Methodology  Freshly mixed samples of Roth 801 sealer, Sealapex® and ProRoot® mineral trioxide aggregate (MTA) were placed in contact with cultured macrophages and fibroblasts for 24 h. The supernatant from the cultures was assayed for PGE2 using enzyme‐linked immunosorbent assay. Cell viability counts were made. As a positive control, similar cultures were also exposed to lipopolysaccharide and the supernatant analysed for PGE2. Data were compared by anova.

Results  The three materials examined in these experiments did not stimulate increased PGE2 release from either of the cell lines. In control cultures, lipolysaccharide increased PGE2 release from macrophages but not from fibroblasts. Viability counts revealed that, whilst Roth 801 sealer caused some cell death in both fibroblasts and macrophages, Sealapex® led to cell death only in the macrophage cultures. ProRoot® MTA did not lead to statistically significant cell death in either culture.

Conclusions  Under 24‐h culture conditions, the three freshly mixed test materials did not increase directly either production or release of PGE2 from either macrophages or gingival fibroblasts. Roth 801 decreased cell viability counts for both fibroblasts and macrophages. Sealapex® decreases macrophage viability. ProRoot® MTA did not affect viability in either cell line.
Healing response of apicomarginal defects to two guided tissue regeneration techniques in periradicular surgery: a double‐blind, randomized‐clinical trial
Authors: Marín‐Botero M. L. , Domínguez‐Mejía J. S. , Arismendi‐Echavarría J. A. , Mesa‐Jaramillo A. L. , Flórez‐Moreno G. A. , Tobón‐Arroyave S. I.
Published: March 2006

Aim  To compare healing responses to periosteal sliding grafts and polyglactin 910 periodontal mesh used as guided tissue regeneration (GTR) materials/techniques when both periapical and periradicular bone loss are present.

Methodology  Thirty patients with suppurative chronic apical periodontitis with apicomarginal communication were selected and allocated randomly into two groups according to the barrier technique to be used during periradicular surgery: periosteal graft group (n = 15) and bioabsorbable membrane group (n = 15). Clinical and radiological evaluations were completed prior to surgery, a week later and every 3 months after surgery up to 12 months to measure the periodontal pocket depth (PD), clinical attachment level (CAL), gingival margin position (GMP), size of periapical lesion, percentage reduction of the periapical rarefaction, and periapical healing.

Results  Both groups showed highly significant (P < 0.001) reductions in periodontal PD, CAL and size of periapical lesion at 12 months whilst GMP was unaltered. No significant difference between the experimental groups was evident for these parameters, or for the percentage reduction of size of the periapical lesion and clinical‐radiographic healing.

Conclusion  Guided tissue regeneration applied to apicomarginal defects using sliding periosteal grafts and use of bioabsorbable membranes led to similar enhancements of the clinical outcome of periradicular surgery in terms of periapical healing, gain of periodontal support, PD reduction and minimal recession of the gingival margin.
Reducing fear of pain associated with endodontic therapy
Authors: Van Wijk A. J. , Hoogstraten J.
Published: March 2006

Aim  To provide subjects with positive information about endodontic treatment (ET) to reduce fear of pain associated with ET.

Methodology  A large sample (n = 437) was randomly allocated to read one of five informative paragraphs and afterwards asked to complete two questionnaires (dental anxiety and fear of dental pain). The paragraphs consisted of dental information obtained from patient brochures. One (experimental) paragraph consisted of positive information about pain during ET. Analysis of variance followed by post hoc analysis was used to detect differences in mean score.

Results  Subjects who were given the positive information regarding ET indicated they were less fearful of pain associated with ET.

Conclusions  The clinical implication of this experiment is that patients should be accurately informed about pain associated with ET. In this way, the patient may be more at ease before and during treatment, decrease avoidance behaviour and make decisions regarding treatment choice, based on common sense rather than fearful expectations.
Evaluation of the effect of EDTA, EDTAC and citric acid on the microhardness of root dentine
Authors: De‐Deus G. , Paciornik S. , Mauricio M. H. P.
Published: March 2006

Aim  To evaluate the effect of citric acid, ethylenediaminetetraacetic acid (EDTA) and ethylenediaminetetraacetic acid plus Cetavlon (EDTAC) solutions on the microhardness of human root canal dentine.

Methodology  Sixteen maxillary human canines were sectioned transversely at the cemento‐enamel junction and the crowns were discarded. Subsequently, each root was embedded in an epoxy resin cylinder and their middle third sectioned horizontally into 4 mm thick slices. The samples were randomly divided into three groups according to the chelating agent employed, as follows (n = 6): group 1: EDTA 17%, group 2: EDTAC 17% and group 3: citric acid 10%. Dentine microhardness was then measured with a load of 50 g for 15 s. At the beginning of the experiment, reference microhardness values were obtained for samples without any etching (t = 0 min). The same samples were then exposed to 50 μL of the chelator solution for 1, 3 and 5 min. The Student's t‐test (P < 0.05) was used to compare results for different times for each chelator and different chelators for each time.

Results  Microhardness decreased with increasing time of application of chelating solutions. There were no significant (P > 0.05) differences between initial microhardness for the three groups as well as after 1 min of application of the substances. After 3 min, EDTA produced a significantly greater reduction in microhardness. However, there was no significant difference between EDTA and EDTAC after 5 min. Citric acid caused significantly less reduction in microhardness.

Conclusions  Overall, citric acid was least effective in reducing dentine hardness whilst EDTA had the strongest effect.
Comparative transcriptome maps: a new approach to the diagnosis of colorectal carcinoma patients using cDNA microarrays
Authors: Jansová E , Koutná I , Krontorád P , Svoboda Z , Křivánková S , Žaloudík J , Kozubek M , Kozubek S
Published: March 2006

The progression of colorectal cancer involves accumulation of various genetic and epigenetic events that dramatically change gene expression. The aim of this study was to investigate a possible new approach to the diagnosis of colorectal carcinoma patients, based on their gene expression profiles. Human 19K cDNA microarrays were used to analyze the gene expression profiles of 18 colorectal carcinoma patients. Transcriptome maps (TMs) were analyzed to detect chromosomal regions that could serve as potential diagnostic markers for colon cancer. A comparison of TMs showed chromosome regions with conserved changes of gene expression typical of colorectal cancer in general, and also patient‐specific variable regions. We identified 195 genes with significantly altered expression in colon cancer. Functional analysis of the regulated genes distinguished three main categories: biological processes, cellular components, and molecular functions. We found that different patients had chromosome regions characterized by very similar changes of gene expression, probably linked to the most fundamental events in carcinogenesis. On the other hand, variable chromosome regions can be patient‐specific. The variable regions may provide further information on the individual pathogenesis and prognosis of the patient. Comparison of TMs is proposed as a tool to facilitate diagnosis and treatment planning for individual patients.
Factors influencing rural health care professionals’ access to continuing professional education
Authors: Curran Vernon R. , Fleet Lisa , Kirby Fran
Published: March 2006

Objectives: The purposes of this study were to explore the perceived barriers and challenges to continuing professional education (CPE) access for Canadian health care professionals and to identify best practices for improving access to CPE.

Design: Key informant interviews and Web‐based online surveys were conducted.

Participants: Key informant interviews were conducted with national CPE accreditation bodies and health professional associations. An online survey was distributed to health professional education programs, as well as provincial professional associations, licensing and professional regulatory bodies.

Main outcome measures: The perceived barriers and challenges to CPE access for Canadian health care professionals and best practices for improving access to CPE.

Results and conclusions: Geographic isolation and poor technological and telecommunications infrastructure were identified as key barriers to CPE delivery and access. Financial factors, such as funding to support travel or cost of attendance, were also identified as major challenges. Tele‐education programming was identified as a best practice approach to improve CPE access, as were regional CPE activities and self‐directed learning programs. Employer‐sponsored initiatives, including staff coverage or locum support, remuneration for time off and paid travel expenses for CPE participation were also identified as best practice approaches.
Caregivers’ inability to identify childhood adiposity: A cross‐sectional survey of rural children and their caregivers’ attitudes
Authors: Fisher Louise , Fraser John , Alexander Christian
Published: March 2006

Objectives:  To determine the prevalence of overweight and obese children in north‐western New South Wales and to assess caregivers’ ability to detect adiposity in their children.

Design:  A cross‐sectional survey using a standardised caregiver questionnaire and anthropometric measurements of school children attending 10 primary schools selected by stratified random sampling.

Subjects:  A total of 598 eligible school children aged between five and eight years.

Measurements:  Body mass index for children; caregivers’ assessment of their children's dietary intake, physical activity and adiposity by questionnaire.

Results:  A total of 348 caregivers responded to the survey, yielding a response rate of 58.2%. Significantly more caregivers of boys (200) than girls (144) chose to participate (χ

2
 = 8.3, d.f. = 1, P < 0.01). The vast majority of caregivers (87%) consented to their children being measured. Body mass index measurements revealed the following: more than three quarters of boys (82%) and girls (77%) were of normal weight. Of boys and girls 13% were overweight. Twice as many girls (6%) than boys (3%) were obese. In total, 31% of caregivers underestimated the weight of their children. This proportion of caregivers underestimating the correct weight category of their children almost doubled to 56% of caregivers of overweight children. Proportionately more caregivers of overweight boys underestimated their children's weight than caregivers of girls (67% compared with 44%).

Conclusion:  Health promotional activities need to address, as a matter of priority, caregivers’ ability to accurately assess the correct weight category of their children.
Exploration of self‐identified education needs of alcohol and other drug workers
Authors: Grootjans John , Hunt Harold , Cresswell Sophi , Robinson Tracy
Published: March 2006

Objective:  It is well established that people who work with clients who are dependent on substances need to be well equipped to deal with challenging and complex situations. Our research explores the experience of alcohol and other drug workers (AODW) in order to identify how successful Australia's teaching institutions are at preparing AODWs to meet this challenge.

Design:  Interviews were conducted to ascertain the perceived gaps in existing training programs and the perceived training needs of AODW. Using a qualitative research approach in‐depth interviews were conducted with more than 20 counsellors working in six AODW rehabilitation centres in regional New South Wales.

Results:  There was a perception among all workers that their training had been inadequate and that the preparation for employment in AODW settings had not meet the felt needs of grass‐roots workers leaving them to learn through experience.

Conclusion:  Considering the recommendations of both national and state policies on AODWs in Australia there is an urgent need to develop courses relevant to the needs of workers as suggested by respondents to this research.
Embryonic dermal condensation and adult dermal papilla induce hair follicles in adult glabrous epidermis through different mechanisms
Authors: Inamatsu Mutsumi , Tochio Takumi , Makabe Aya , Endo Tetsuya , Oomizu Souichi , Kobayashi Eiji , Yoshizato Katsutoshi
Published: March 2006

Hair induction in the adult glabrous epidermis by the embryonic dermis was compared with that by the adult dermis. Recombinant skin, composed of the adult sole epidermis and the embryonic dermis containing dermal condensations (DC), was transplanted onto the back of nude mice. The epidermis of transplants formed hairs. Histology on the induction process demonstrated the formation of placode‐like tissues, indicating that the transplant produces hair follicles through a mechanism similar to that underlying hair follicle development in the embryonic skin. An isolated adult rat sole skin piece, inserted with either an aggregate of cultured dermal papilla (DP) cells or an intact DP between its epidermis and dermis, was similarly transplanted. The transplant produced hair follicles. Histology showed that the epidermis in both cases surrounded the aggregates of DP cells. The epidermis never formed placode‐like tissues. Thus, it was concluded that the adult epidermal cells recapitulate the embryonic process of hair follicle development when exposed to DC, whereas they get directly into the anagen of the hair cycle when exposed to DP. The expression pattern of Edar and Shh genes, and P‐cadherin protein during the hair follicle development in the two types of transplants supported the above conclusion.
Subequatorial cytoplasm plays an important role in ectoderm patterning in the sea urchin embryo
Authors: Kominami Tetsuya , Akagawa Megumi , Takata Hiromi
Published: March 2006

To gain information on the process of ectoderm patterning, the animal halves of sea urchin embryos were isolated at various stages, and their morphology was examined when control embryos developed into pluteus larvae. The animal halves separated at the 8‐cell stage developed into ‘dauerblastula’, without showing any conspicuous ectoderm differentiation. In contrast, some of the animal halves isolated at the 60‐cell stage (after the sixth cleavage) formed a ciliated band and oral opening, suggesting that some patterning signal was transmitted from the vegetal to animal hemisphere during early cleavage. Further patterning of the animal hemisphere did not seem to occur until hatching, since both the animal halves isolated at the 60‐cell stage and hatching stage showed the same degree of ectoderm patterning. After hatching, the later animal halves were isolated, the more patterned ectoderm they formed. The animal halves isolated just prior to gastrulation differentiated well‐patterned ectoderm. It is of note, however, that the level of separation was a more crucial factor than the timing of separation; even the animal fragments of newly hatched embryos differentiated well‐patterned ectoderm if they had been separated at a subequatorial level. This suggests that the signal for ectoderm patterning is transmitted over the equator after hatching, and once the cells in the supra‐equatorial region receive the signal, they, in turn, can transmit the signal upwardly. Interestingly, if the third cleavage plane was shifted toward the vegetal pole, the isolated animal pole‐side fragments developed into ‘embryoids’ with fully patterned ectoderm. These results indicate that not the micromere descendants but the subequatorial cytoplasm plays an important role in ectoderm patterning.
Therapeutic effects of 10 mg/day rabeprazole administration on reflux esophagitis was not influenced by the CYP2C19 polymorphism
Authors: Ariizumi Ken , Ohara Shuichi , Koike Tomoyuki , Inomata Yoshifumi , Iijima Katsunori , Sekine Hitoshi , Noguchi Mitsunori , Sugiyama Koichi , Eda Yoshiki , Kayaba Shoichi , Kawamura Msashi , Shimosegawa Tooru
Published: March 2006

Background:  The acid suppressive effects of omeprazole (OPZ) and lansoprazole (LPZ) are influenced by the CYP2C19 polymorphism. On the other hand, some investigators have reported that acid suppressive effect of rabeprazole (RPZ) was not significantly affected by CYP2C19. The present study was designed to investigate whether the CYP2C19 genotype is related to the healing of reflux esophagitis (RE) in treatment with RPZ 10 mg.

Methods:  One hundred and three Japanese patients with RE were treated with daily oral administration of 10 mg RPZ. At 4 and 8 weeks after the start of treatment, healing of RE was evaluated endoscopically. The CYP2C19 genotype was investigated before the treatment.

Results:  At 4 weeks after the start of treatment, the healing rates for homo‐extensive metabolizer, hetero‐extensive metabolizer, and poor metabolizer patients were 86.1% (31/36), 92.0% (46/50), and 82.4% (14/17), respectively, and at 8 weeks after the start of treatment, the healing rates were 86.1% (31/36), 92.0% (46/50), and 82.4% (14/17), respectively. There were no significant differences in the healing rate of RE among the three genotypes at either 4 or 8 weeks after the start of treatment.

Conclusions:  The therapeutic effects of 10 mg/day RPZ administration on RE may be uninfluenced by the CYP2C19 polymorphism.
Changing prevalence, clinical features, and outcome of acute hepatitis in Spain (1982–2003)
Authors: Del Olmo Juan A , Ornia Elena , Serra Miguel A , Garcia‐Torres Maria‐Luisa , Escudero Amparo , Rodriguez Felicidad , Rodrigo José M
Published: March 2006

Background:  Diagnostic and preventive measures have contributed to a change in the epidemiology of acute hepatitis. The purpose of the present paper was to assess the changing prevalence of acute hepatitis from 1982 to 2003.

Methods:  Trends in the epidemiology, clinical findings, and outcome of acute viral hepatitis from 1982 to 2003 were examined. A total of 548 episodes of acute hepatitis diagnosed between 1982 and 2003, the clinical course of which was monitored up to the year 2003, were included. Annual changes as well as for the intervals 1982–1992 and 1993–2003 were compared.

Results:  Severe infections occurred in 1.3% of cases, with a mortality of 0.6%, with progression into chronicity in 25.1%. The annual incidences of acute hepatitis and the comparative intervals 1982–1992 and 1993–2003 showed a decline of parenterally –B, delta and C virus‐ transmitted infections, unchanged number of cases of acute hepatitis A, an increase in the number of cases of drug‐induced hepatitis, increase in median ages, and a decrease in the proportion of hepatitis in injecting drug users. Ages of patients with hepatitis A tended to increase.

Conclusions:  A decline of parenterally transmitted acute hepatitis was documented throughout a 22‐year period, while the number of cases of hepatitis A was unchanged and that of drug‐induced hepatitis increased. Evaluation of the current targeted hepatitis A vaccination approach and adequate pharmacovigilance measures are required in the near future.
Opioid system blockade decreases collagenase activity and improves liver injury in a rat model of cholestasis
Authors: Kiani Samira , Ebrahimkhani Mohammad R , Shariftabrizi Ahmad , Doratotaj Behzad , Payabvash Seyedmehdi , Riazi Kiarash , Dehghani Mehdi , Honar Hooman , Karoon Alaleh , Amanlou Massoud , Tavangar Seyed M , Dehpour Ahmad R
Published: March 2006

Background:  Following bile duct ligation (BDL) endogenous opioids accumulate in plasma and play a role in the pathophysiology and manifestation of cholestasis. Evidence of centrally mediated induction of liver injury by exogenous opioid agonist administration, prompts the question of whether opioid receptor blockade by naltrexone can affect cholestasis‐induced liver injury.

Methods:  Cholestasis was induced by BDL and cholestatic and sham‐operated rats received either naltrexone or saline for 7 consecutive days. On the 7th day, liver samples were collected for determining matrix metalloproteinase‐2 (MMP‐2) activity, S‐adenosylmethionine (SAM) and S‐adenosylhomocysteine (SAH) content and blood samples were obtained for measuring plasma nitrite/nitrate and liver enzyme activities.

Results:  Naltrexone‐treated BDL animals had a significant reduction in plasma enzyme activity and nitrite/nitrate level. Liver SAM : SAH ratio and SAM level improved by naltrexone treatment in cholestatic animals compared to saline‐treated BDL ones. Naltrexone treatment in BDL rats led to a decrease in the level of liver MMP‐2 activity, which had already increased during cholestasis.

Conclusion:  Opioid receptor blockade improved the degree of liver injury in cholestasis, as assessed by plasma enzyme and liver MMP‐2 activities. The beneficial effect of naltrexone may be due to its ability to increase liver SAM level and restore the SAM : SAH ratio.
Comparative aspects of cerebral cortical development
Authors: Molnár Zoltán , Métin Christine , Stoykova Anastassia , Tarabykin Victor , Price David J. , Francis Fiona , Meyer Gundela , Dehay Colette , Kennedy Henry
Published: March 2006

This review aims to provide examples of how both comparative and genetic analyses contribute to our understanding of the rules for cortical development and evolution. Genetic studies have helped us to realize the evolutionary rules of telencephalic organization in vertebrates. The control of the establishment of conserved telencephalic subdivisions and the formation of boundaries between these subdivisions has been examined and the very specific alterations at the striatocortical junction have been revealed. Comparative studies and genetic analyses both demonstrate the differential origin and migratory pattern of the two basic neuron types of the cerebral cortex. GABAergic interneurons are mostly generated in the subpallium and a common mechanism governs their migration to the dorsal cortex in both mammals and sauropsids. The pyramidal neurons are generated within the cortical germinal zone and migrate radially, the earliest generated cell layers comprising preplate cells. Reelin‐positive Cajal–Retzius cells are a general feature of all vertebrates studied so far; however, there is a considerable amplification of the Reelin signalling with cortical complexity, which might have contributed to the establishment of the basic mammalian pattern of cortical development. Based on numerous recent observations we shall present the argument that specialization of the mitotic compartments may constitute a major drive behind the evolution of the mammalian cortex. Comparative developmental studies have revealed distinct features in the early compartments of the developing macaque brain, drawing our attention to the limitations of some of the current model systems for understanding human developmental abnormalities of the cortex. Comparative and genetic aspects of cortical development both reveal the workings of evolution.
Recent progress in understanding the role of Reelin in radial neuronal migration, with specific emphasis on the dentate gyrus
Authors: Förster Eckart , Jossin Yves , Zhao Shanting , Chai Xuejun , Frotscher Michael , Goffinet André M.
Published: March 2006

Ten years following identification of Reelin as the product of the gene mutated in reeler mice, the signalling pathway activated by Reelin is being progressively unravelled with the identification of lipoprotein receptors as reelin receptors, of the Dab1 adapter and of some other proximal components in target cells. However, we are still a long way from understanding the action of this complex protein during brain development and maturation. The present review is organized in two parts. First, we summarize our present understanding of Reelin signalling. Then, we review critically some cell biological mechanisms for the action of Reelin based on recent studies on the development of the dentate gyrus, which has proved an extremely useful and tractable model system.
Astrocytes promote neurogenesis from oligodendrocyte precursor cells
Authors: Gaughwin P. M. , Caldwell M. A. , Anderson J. M. , Schwiening C. J. , Fawcett J. W. , Compston D. A. S. , Chandran S.
Published: March 2006

The oligodendrocyte precursor cell (OPC) has until recently been regarded as a lineage‐restricted precursor cell. Considerable interest has been generated by reports suggesting that OPCs may possess a wider differentiation potential than previously assumed and thus be considered a multipotential stem cell. This study examined the neuronal differentiation potential of rat, postnatal cortical OPCs in response to extracellular cues in vitro and in vivo. OPCs did not exhibit intrinsic neuronal potential and were restricted to oligodendrocyte lineage potential following treatment with the neural precursor mitogen fibroblast growth factor 2. In contrast, a postnatal hippocampal astrocyte‐derived signal(s) is sufficient to induce functional neuronal differentiation of cortical OPCs in vitro in population and single cell studies. Co‐treatment with Noggin, a bone morphogenetic protein antagonist, did not attenuate neuronal differentiation. Following transplantation to the adult rat hippocampus, cortical OPCs expressed doublecortin, a neuroblast‐associated marker. The present findings show that hippocampal, astrocyte‐derived signals can induce the neuronal differentiation of OPCs through a Noggin‐independent mechanism.
Cell and molecular mechanisms involved in the migration of cortical interneurons
Authors: Métin Christine , Baudoin Jean‐Pierre , Rakić Sonja , Parnavelas John G.
Published: March 2006

Since the discovery that the vast majority of the GABA‐containing interneurons of the cerebral cortex arise in the subpallium, considerable effort has been put into the description of the precise origin of these neurons in subdivisions of the ganglionic eminence and in the migratory routes they follow on their way to the developing cortex. More recently, studies have focused on the molecular and cellular mechanisms that guide their migration. Investigations of the molecular mechanisms involved have demonstrated important roles for numerous transcription factors, motogenic factors and guidance molecules. Here, we review results of very recent analyses of the underlying cellular mechanisms and specifically of the movement of the nucleus, cytoplasmic components and neuritic processes during interneuron migration.
Long‐term neuronal replacement in adult rat hippocampus after status epilepticus despite chronic inflammation
Authors: Bonde Sara , Ekdahl Christine T. , Lindvall Olle
Published: March 2006

Dentate gyrus (DG) neurogenesis is transiently increased during the first weeks after status epilepticus (SE). Survival of the new neurons is initially compromised by an acute inflammatory response, but the long‐term fate of the remaining ones in the post‐SE environment is unknown. Here adult rats were subjected to 2 h electrically evoked self‐sustained SE and perfused after 5 weeks or 6 months. Rats exhibited partial or generalized SE followed by spontaneous behavioural seizures and abnormal electroencephalographic activity during 6 months. Numbers of activated microglia in the dentate subgranular zone (SGZ)‐granule cell layer (GCL) and in the hilus declined after 5 weeks, but were still elevated at 6 months after SE, with no differences between the milder partial and the more severe generalized SE. At 6 months, partial and generalized SE rats showed a seven‐fold increase in the number of mature SGZ–GCL neurons formed during the first 2 weeks along with aberrant neurons in the hilus. Total numbers of mature neurons in SGZ–GCL were unaltered, indicating that SE‐generated neurons replaced dead granule cells. Neuroblast formation had returned to normal levels in SGZ–GCL but generation of aberrant neurons in the hilus was still ongoing at 6 months. Our data indicate that long‐term impairment of neurogenesis, as reported previously after kainic acid‐induced SE, is not a general feature of chronic epilepsy. We have found that a substantial proportion of the mature granule cells at 6 months are generated during the first 2 weeks after SE and survive despite chronic inflammation, and that SE triggers continuous production of aberrant hilar neurons.
Dopamine efflux in the rat striatum evoked by electrical stimulation of the subthalamic nucleus: potential mechanism of action in Parkinson's disease
Authors: Lee Kendall H. , Blaha Charles D. , Harris Brent T. , Cooper Shannon , Hitti Frederick L. , Leiter James C. , Roberts David W. , Kim Uhnoh
Published: March 2006

The precise mechanism whereby continuous high‐frequency electrical stimulation of the subthalamic nucleus ameliorates motor symptoms of Parkinson's disease is unknown. We examined the effects of high‐frequency stimulation of regions dorsal to and within the subthalamic nucleus on dopamine efflux in the striatum of urethane‐anaesthetized rats using constant potential amperometry. Complementary extracellular electrophysiological studies determined the activity of subthalamic nucleus neurons in response to similar electrical stimulation of the subthalamic nucleus. High‐frequency stimulation of the subthalamic nucleus increased action potential firing in the subthalamic nucleus only during the initial stimulation period and was followed by a cessation of firing over the remainder of stimulation. Electrical stimulation of the subthalamic nucleus with 15 pulses elicited stimulus‐time‐locked increases in striatal dopamine efflux with maximal peak effects occurring at 50 Hz frequency and 300 µA intensity. Extended subthalamic nucleus stimulation (1000 pulses at 50 Hz; 300 µA) elicited a similar peak increase in striatal dopamine efflux that was followed by a relatively lower steady‐state elevation in extracellular dopamine over the course of stimulation. In contrast, extended stimulation immediately adjacent and dorsal to the subthalamic nucleus resulted in an 11‐fold greater increase in dopamine efflux that remained elevated over the course of the stimulation. Immunohistochemical staining for tyrosine hydroxylase revealed catecholaminergic fibers running immediately dorsal to and through the subthalamic nucleus. Taken together, these results suggest that enhanced dopamine release within the basal ganglia may be an important mechanism whereby high‐frequency stimulation of the subthalamic nucleus improves motor symptoms of Parkinson's disease.
FACILITATING CHOICE IN ENGLISH LOCAL GOVERNMENT
Authors: Bailey Stephen J.
Published: March 2006

This paper examines recent policies to enhance the scope for choice by the users of local government services in England. It questions whether they can offset the progressively increasing restriction of local democratic choices that have resulted from the trend towards increasing centralisation of local finance and statutory controls over service standards.
MODERNISING LOCAL GOVERNMENT
Authors: Rao Nirmala
Published: March 2006

Reform of local government has been a central part of the Blair governments’‘modernisation’ agenda. This article examines four specific aspects of the modernisation of local government: the implications of constitutional change for councillor roles; the direct election of mayors; new arrangements for the scrutiny of executive action; and the dilemmas and challenges facing local government officers. It argues that the Blair reforms have brought about significant changes to the organisation and operation of local authorities, but whether the reforms have achieved the government's objectives remains open to question.
PROPERTY RIGHTS AND THE GENERAL THEORY OF EXCHANGE: FREQUENTLY NEGLECTED IMPLICATIONS OF THE DIVISION OF LABOUR AND THE LAW OF COMPARATIVE ADVANTAGE
Authors: Ayau Manuel F.
Published: March 2006

The importance of the division of labour and the law of comparative advantage to the operation of modern economies are well known, but many of the implications of these phenomena are less widely appreciated. This article examines the implications of the division of labour and the law of comparative advantage for the ownership and exercise of property rights and the creation and distribution of wealth. It is argued that a fuller appreciation of these phenomena leads to the conclusion that restraints on trade and redistributory measures infringe private property rights and reduce wealth.
THE POLITICAL ECONOMY OF OVERLAPPING JURISDICTIONS AND THE FRENCH/DUTCH REJECTION OF THE EU CONSTITUTION
Authors: Migué Jean‐Luc
Published: March 2006

In seeking to protect their failed social model by rejecting the EU constitution, French and Dutch voters ironically contributed to promoting the very ‘liberal’ order they misunderstand and despise. When, as in federalist politics, functions overlap, two levels of government compete for the same votes in the same territory in the supply of similar services. Not unlike the tragedy of the commons in oil extraction, it is in the interest of both political authorities to seek to gain votes in implementing the programme first. The overall equilibrium supply of public services is excessive and both levels of government have a tendency to invade every field. Short of effective constitutional limits on the powers of the central government, a more decentralised EU offers an opportunity to overcome the common‐pool problem of multi‐level government.
PLANNING BY NEGOTIATION FOR SUSTAINABLE DEVELOPMENT: A TALE OF TWO HABITATS
Authors: Lai Lawrence W. C. , Lorne Frank T.
Published: March 2006

In the December 2005 issue of Economic Affairs, a collection of authors considered alternative institutions for planning and managing urban affairs. Following up the idea of ‘planning by contract’, this paper reflects on the role of negotiation in securing gains from trade over contested local environmental resources. The idea of an obstructive classical planning game is contrasted with the concept of creative negotiation by reference to two case studies.
PUBLIC CHOICE THEORY, PROTECTIONISM AND THE CASE OF NAFTA
Authors: Quartner David
Published: March 2006

Public choice theory suggests that the political process has an in‐built tendency to promote protectionist measures favoured by organised interest groups rather than trade liberalisation that would benefit society as a whole. But the example of the North American Free Trade Agreement shows that political campaigns in support of free trade can successfully mobilise public opinion to neutralise the power of special‐interest groups. Therefore, it is imperative that politicians and others who believe in free trade remind the public of its benefits.
Cutaneous myospherulosis and membranous lipodystrophy: extensive presentation in a patient with severe steroid‐induced dermal atrophy
Authors: Flagothier C , Piérard GE , Quatresooz P
Published: March 2006

Myospherulosis is a rare disorder that may develop in various organs including the skin. It is characterized by a typical histological presentation resulting from the interaction between erythrocytes and lipids. We present a case of cutaneous myospherulosis associated with membranous lipodystrophy. The lesions were supervening on severe steroid‐induced skin atrophy upon which ointments had been applied.
Hemodynamic profile, compensation deficit, and ambulatory blood pressure
Authors: Ottaviani Cristina , Shapiro David , Goldstein Iris B. , James Jack E. , Weiss Robert
Published: March 2006

This study hypothesized that physiologically grounded patterns of hemodynamic profile and compensation deficit would be superior to traditional blood pressure reactivity in the prediction of daily‐life blood pressure. Impedance cardiography‐derived measures and beat‐to‐beat blood pressure were monitored continuously in 45 subjects during baseline and four tasks. Ambulatory blood pressure measures were obtained combining data from one work day and one off day. The mediating effects of gender and family history of hypertension were considered. Only gender was significantly associated with hemodynamic profile. Regression analysis indicated that typical reactivity measures failed to predict everyday life blood pressure. After controlling for gender and baseline blood pressure, hemodynamic patterns during specific tasks proved to be strong predictors, overcoming limitations of previous reactivity models in predicting real‐life blood pressure.
Expressive suppression during an acoustic startle
Authors: Hagemann Tim , Levenson Robert W. , Gross James J.
Published: March 2006

Previous studies have shown that inhibiting negative or positive emotion‐expressive behavior leads to increased sympathetic activation. Inhibiting facial behavior while in an affectively neutral state has no such physiological consequences. This suggests that there may be something special about inhibiting emotion‐expressive behavior. To test the boundary conditions of the suppression effect, acoustic startles were delivered to 252 participants in three experimental groups. Participants in one group received unanticipated startles. Participants in the other two groups were told that after a 20‐s countdown a loud noise would occur; participants in one of these groups were further told to inhibit their expressive behavior. Results indicated that startle suppression increased sympathetic activation. These findings extend prior work on emotion suppression, and suggest that inhibiting other biologically based responses also may be physiologically taxing.
Relatedness proportion effects on masked associative priming: An ERP study
Authors: Grossi Giordana
Published: March 2006

The effect of relatedness proportion (the percentage of related words in a list) on associative priming was investigated in two masked priming experiments. In Experiment 1, subjects were randomly assigned to either a high (80%) or low (20%) relatedness proportion condition and performed a lexical decision task. Semantically related and unrelated primes were briefly flashed (50 ms) before the targets and were preceded by a mask that prevented their overt identification. In Experiment 2, subjects were tested in both relatedness proportion conditions in a categorization task; the N400, an electrophysiological index of lexical and semantic priming, was measured in trials that did not require a button press. Behavioral and electrophysiological priming effects were observed in both high and low relatedness proportion conditions. The observed priming effects were not modulated by relatedness proportion. The results are discussed in terms of current theories of associative priming.
Separated by common ground? Bringing (post)development and (post)colonialism together
Authors: SIMON DAVID
Published: March 2006

The relationship between mainstream development policy (and perhaps also development studies) and postcolonial theorists has often been characterized as a dialogue of the deaf. Rather like in the old ‘debates’ between adherents of modernization and neo‐Marxist theories, the protagonists are often thought to be talking at or past one another, rather than with each other. This paper reassesses some firmly held views on both sides of the schism. On the one hand, many official development agencies appear to promote business as usual (often quite literally, as a recent War on Want report attests in the case of the UK's DFID using its aid budget to promote profitable opportunities for British corporations). On the other hand, some postcolonial purists rely on surprisingly modernist, totalizing discursive techniques while claiming post‐structural credentials, or baulk at the prospects of practical engagement. Discrepancies between theory, discourse, policy and practice are not the preserve of one side. However, the middle ground is firmer and better trodden than most believe. Considerable progress has been made and the paper assesses examples of productive engagement and concludes with suggestions for carrying forward the challenges.
Subaltern strategies and development practice: urban water privatization in Ghana
Authors: YEBOAH IAN
Published: March 2006

This paper is concerned with subaltern actions providing alternatives to development practice. I use Ghana's attempt at urban water privatization to illustrate that Ghana's development practice is characterized by a dependence on foreign sources of capital and expertise that illustrates a psyche and mindset of Eurocentrism associated with the elite and decisionmakers of the country. The rationale for water privatization, the how of privatization, and the anti‐development opposition to privatization not only demonstrate this dependency but also the extent to which decisionmakers are willing to sacrifice sovereignty and culturally sensitive ways of doing things, to global capital, in exchange for development funds. In the state's zeal for Western or Occidental development, subalterns in Ghana have devised hybridities that are post‐traditional and Oriental in nature to solve their water problems. These development solutions are couched within structures provided to human agency and suggest that development practice should therefore listen to subalterns in terms of how they imagine and solve their problems. The concern with subaltern voices shows the relationship between postcolonial studies and development practice.
Implant survival in mandibles of irradiated oral cancer patients
Authors: Yerit Kaan C. , Posch Martin , Seemann Maximilian , Hainich Sibylle , Dörtbudak Orhun , Turhani Dritan , Özyuvaci Hakan , Watzinger Franz , Ewers Rolf
Published: March 2006

Objective: The aim of this study was to analyze long‐term implant survival in the mandible after radiotherapy and radical surgery in oral cancer patients.

Study design: Between 1990 and 2003, 71 patients (15 females, 56 males; average age 57.8 years, range 16–84.1 years) were treated with dental implants after radiochemotherapy and ablative surgery of oral cancer. Radiation therapy was delivered in daily fractions of 2 Gy given on 25 days (total dose of 50 Gy). Oral defects were reconstructed microsurgically with jejunal, iliac crest or radial forearm grafts. Thereafter 316 dental implants were placed in the non‐irradiated residual bone (84; 27%), irradiated residual bone (154; 49%) or grafted bone (78; 25%) at various intervals (mean interval 1.41 (±1.01) years, range 0.34–6.35 years).

Results: The mean follow‐up time after implant insertion was 5.42 (±3.21) years (range 0.3–13.61 years). The overall 2‐, 3‐, 5‐, and 8‐year survival rates of all implants were 95%, 94%, 91% and 75%. Forty‐four implants were lost in 21 patients during the observation period. Irradiation of the mandibular bone showed significantly (P=0.0028) lower implant survival compared with non‐irradiated mandibular bone. The 8‐year survival rate in the non‐irradiated residual bone (two loss), irradiated residual bone (29 loss) or grafted bone (13 loss) were 95%, 72% and 54%, respectively. Time of implantation after irradiation showed no statistically significant influence. Implant brand, length or diameter or the incidence of resective surgery on the mandible and gender of patients had no statistically significant influence on implant survival.

Conclusion: Radiation therapy with 50 Gy was significantly related to shorter implant survival in mandibular bone. Survival was lowest in grafted bone. Time of implant placement had no statistically significant influence on survival under the conditions of this study. Although implant survival is lower in irradiated mandibles, implants significantly facilitate prosthodontic treatment and enhance outcome of oral rehabilitation in cancer patients.
Platelet releasate increases the proliferation and migration of bone marrow‐derived cells cultured under osteogenic conditions
Authors: Kark Lianne R. , Karp Jeffrey M. , Davies John E.
Published: March 2006

Abstract: Concentrated platelets and their products are currently being used as a clinical tool to accelerate endosseous wound healing. However, there is little understanding regarding the actions of platelets and platelet‐released products on osteogenic cells. We show, herein, that releasate from thrombin‐activated platelets increases the migration and proliferation of osteogenic cultures of bone marrow cells. Using a scratch wound assay, we demonstrated that platelet releasate (PR) stimulated up to a 2.4±0.5‐fold increase in wound closure in serum‐free medium, relative to a control containing thrombin. In the presence of serum, the addition of PR resulted in a 1.45±0.13‐fold increase in scratch closure. To isolate cell migration from the effects of cell proliferation, cell monolayers were pre‐incubated with 5, 10 and 20 μg/ml of Mitomycin C (MMC), which is a potent inhibitor of cell proliferation. This resulted in a large decrease in the leading front of scratch closure, which indicates that PR stimulated cell mitogenesis. However, irrespective of MMC pre‐treatment, PR stimulated a motogenic response. These results provide evidence of possible mechanisms by which platelets could influence bone regeneration.
DETERMINATION OF GLOMERULAR FILTRATION RATE IN DOGS USING CONTRAST‐ENHANCED COMPUTED TOMOGRAPHY
Authors: O'DELL‐ANDERSON KRISTEN J. , TWARDOCK ROBERT , GRIMM JENNIFER B. , GRIMM KURT A. , CONSTABLE PETER D.
Published: March 2006

The purpose of this project was to establish a procedure and reference values for glomerular filtration rate (GFR) using contrast‐enhanced computed tomography (CT) in eight healthy dogs. A single section of the kidney was scanned sequentially after bolus injection (3 ml/s) of iohexol (300 mg/kg). Time–attenuation curves were constructed and the GFR per volume of kidney was calculated using Patlak graphical analysis software. The GFR was then converted from contrast clearance per unit volume (ml/min/ml) to contrast clearance per body weight (ml/min/kg). Individual kidney and global GFR were calculated using both CT and nuclear scintigraphy. Global GFR for each dog was also determined by plasma iohexol clearance. Contrast‐enhanced CT underestimated the global GFR compared with the other two methods. The average global GFR was 2.57±0.33 ml/min/kg using functional CT and 4.06±0.37 ml/min/kg using plasma iohexol clearance. There was significant (P<0.05) interobserver variability of CT GFR of the right kidney and total GFR. There was decreased interobserver variability for the left kidney. There was no difference in the intraobserver variability for CT‐determined individual kidney and global GFR. There was no difference between the motion corrected and nonmotion corrected values for individual and global CT GFR. Nuclear scintigraphy produced a slightly higher coefficient of variation than contrast‐enhanced CT, 2.9% and 1.0%, respectively. It is hypothesized that altered renal blood flow, hematocrit of the small vessels, and nephrotoxicity play a role in the underestimation of GFR by contrast‐enhanced CT.