bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral ischemia/stroke and small ubiquitin‐like modifier (SUMO) conjugation – a new target for therapeutic intervention?
Authors: Yang Wei , Sheng Huaxin , Homi H. Mayumi , Warner David S. , Paschen Wulf
Published: April 2008

Transient cerebral ischemia/stroke activates various post‐translational protein modifications such as phosphorylation and ubiquitin conjugation that are believed to play a major role in the pathological process triggered by an interruption of blood supply and culminating in cell death. A new system of post‐translational protein modification has been identified, termed as small ubiquitin‐like modifier (SUMO) conjugation. Like ubiquitin, SUMO is conjugated to the lysine residue of target proteins in a complex process. This review summarizes observations from recent experiments focusing on the effect of cerebral ischemia on SUMO conjugation. Transient global and focal cerebral ischemia both induced a rapid, dramatic and long‐lasting rise in levels of SUMO2/3 conjugation. After transient focal cerebral ischemia, SUMO conjugation was particularly prominent in neurons located at the border of the ischemic territory where SUMO‐conjugated proteins translocated to the nucleus. Many SUMO conjugation target proteins are transcription factors and sumoylation has been shown to have a major impact on the activity, stability, and cellular localization of target proteins. The rise in levels of SUMO‐conjugated proteins is therefore likely to have a major effect on the fate of post‐ischemic neurons. The sumoylation process could provide an exciting new target for therapeutic intervention.
Alpha‐synuclein aggregation and cell death triggered by energy deprivation and dopamine overload are counteracted by D2/D3 receptor activation
Authors: Bellucci Arianna , Collo Ginetta , Sarnico Ilenia , Battistin Leontino , Missale Cristina , Spano PierFranco
Published: April 2008

Progressive degeneration and intraneuronal Lewy bodies made of filamentous α‐synuclein (α‐syn) in dopaminergic cells of the nigrostriatal system are characteristics of Parkinson’s disease (PD). Glucose uptake is reduced in some of the brain regions affected by PD neurodegenerative changes. Defects in mitochondrial activity in the substantia nigra have been observed in the brain of patients affected by PD and substantia nigra lesions can induce the onset of a secondary parkinsonism. Thus, energy starvation and consequently metabolic impairment to dopaminergic neurons may be related to the onset of PD. On this line, we evaluated the effect of nutrient starvation, reproduced ‘in vitro’ by glucose deprivation (GD), in primary mesecephalic neuronal cultures and dopaminergic‐differentiated SH‐SY5Y cells, to evaluate if decreased glucose support to dopaminergic cells can lead to mitochondrial damage, neurodegeneration and α‐syn misfolding. Furthermore, we investigated the effect of dopamine (DA) treatment in the presence of a DA‐uptake inhibitor or of the D2/D3 receptor (D2R/D3R) agonist quinpirole on GD‐treated cells, to evaluate the efficacy of these therapeutic compounds. We found that GD induced the formation of fibrillary aggregated α‐syn inclusions containing the DA transporter in dopaminergic cells. These alterations were accompanied by dopaminergic cell death and were exacerbated by DA overload. Conversely, the block of DA uptake and D2R/D3R agonist treatment exerted neuroprotective effects. These data indicate that glucose starvation is likely involved in the induction of PD‐related pathological changes in dopaminergic neurons. These changes may be counteracted by the block of DA uptake and by dopaminergic agonist treatment.
A Study of the Fatigue Behaviour of an Aluminium‐Clad Steel Material Compound
Authors: Lamik A. , Leitner H. , Eichlseder W. , Riemelmoser F.
Published: April 2008

Abstract:  In this study we dealt with the characterisation of an aluminium‐clad steel material compound and the influence of the manufacturing process on its fatigue behaviour. As components of the Al6016‐T4/FeP06 material compound are manufactured predominantly by rolling and deep drawing, the influence of the plastic deformation during manufacturing on the fatigue behaviour must be investigated. Particularly, the cyclic hardening behaviour of FeP06 has a marked effect on the fatigue life of the aluminium–steel compound. Simulation models for fatigue life estimation of this material compound must therefore consider the influence of the plastic deformation which occurs, e.g. during deep drawing, on the fatigue behaviour. This study focused on the technological influences of the rolling process on the fatigue behaviour of an AA6016‐T4/FeP06 compound. The influence of the load sequence on the S/N‐curve of FeP06 was also studied.
Ultrasonic Characterisation of Porous Biomaterials Across Different Frequencies
Authors: Kohlhauser C. , Hellmich C. , Vitale‐Brovarone C. , Boccaccini A. R. , Rota A. , Eberhardsteiner J.
Published: April 2008

Abstract:  Mechanical testing is the most common experimental technique to determine elastic stiffness of materials. In case of porous materials, especially such with very high porosity, the determination of material stiffness may be strongly biased by inelastic deformations occurring in the material samples, especially in the vicinity of the load transfer devices, such as loading platens. In contrast, ultrasonic waves propagating through a material generate very small stresses and strains (and also strain rates lying in the ‘quasistatic’ regime). Thus, they enable the direct determination of the components of elastic stiffness tensors of materials, and also of those with a very high porosity. We shortly revisit from the theoretical basis of continuum (micro)mechanics that, depending on the frequency of the employed acoustical signals, the investigated materials are characterised at different observation scales, e.g. the elasticity of the overall porous medium, or that of the solid matrix inside the material are determined. We here report the elastic properties of biomaterials and biological materials at different length scales, by using ultrasound frequencies ranging from 100 kHz to 20 MHz. We tested isotropic scaffolds for biomedical engineering, made up of porous titanium and two different bioactive glass–ceramics, and we also determined the direction‐dependent normal and shear stiffness components of the anisotropic natural composite ‘spruce wood’.
Measurement of Operating Forces in a Ram Press Crushing Sunflower Seed
Authors: Foster J. D. G. , Uziak J. , Loukanov I. A.
Published: April 2008

Abstract:  This study presents the experimental setup and results of measurement of forces and moments in a manually operated ram press machine. Tests were conducted on a BP30 ram press using electrical resistance strain gauges to measure forces present in the machine under operating conditions. The forces were obtained by capturing data for the strains in six channels, using a digital instrument system, and later calculated by using the sensitivity factors. A method was proposed to estimate the tension force and bending moment in the connecting rods based on the sums and differences of measured strains. Results obtained were converted into spreadsheet data and presented in graphs versus the position angle of the operating lever.
A multi‐agent approach for dynamic channel allocation
Authors: Pendharkar Parag C.
Published: April 2008

We propose a multi‐agent approach for dynamic channel allocation (MA‐DCA) in mobile cellular networks. Our approach assumes that each cell in a cellular network works as an agent that negotiates its bandwidth (channel) requirements with its neighbors to minimize its call drop probability. Using stochastic simulation, we compare our MA‐DCA approach with simple fixed channel allocation (FCA) and dynamic channel borrowing approaches for different call arrival rates, cellular network sizes and number of available channels. The results of our experiments show that the proposed MA‐DCA approach performs better than dynamic channel borrowing and FCA approaches.
Decreased hippocampal volume on MRI is associated with increased extracellular glutamate in epilepsy patients
Authors: Cavus Idil , Pan Jullie W. , Hetherington Hoby P. , Abi‐Saab Walid , Zaveri Hitten P. , Vives Kenneth P. , Krystal John H. , Spencer Susan S. , Spencer Dennis D.
Published: April 2008

Summary

Purpose: Temporal lobe epilepsy (TLE) is associated with smaller hippocampal volume and with elevated extracellular (EC) glutamate levels. We investigated the relationship between the hippocampal volume and glutamate in refractory TLE patients.

Methods: We used quantitative MRI volumetrics to measure the hippocampal volume and zero‐flow microdialysis to measure the interictal glutamate, glutamine, and GABA levels in the epileptogenic hippocampus of 17 patients with medication‐resistant epilepsy undergoing intracranial EEG evaluation. The relationships between hippocampal volume, neurochemical levels, and relevant clinical factors were examined.

Results: Increased EC glutamate in the epileptogenic hippocampus was significantly related to smaller ipsilateral (R2= 0.75, p < 0.0001), but not contralateral hippocampal volume when controlled for glutamine and GABA levels, and for clinical factors known to influence hippocampal volume. Glutamate in the atrophic hippocampus was significantly higher (p = 0.008, n = 9), with the threshold for hippocampal atrophy estimated as 5 μM. GABA and glutamine levels in the atrophic and nonatrophic hippocampus were comparable. Decreased hippocampal volume was related to higher seizure frequency (p = 0.008), but not to disease duration or febrile seizure history. None of these clinical factors were related to the neurochemical levels.

Conclusions: We provide evidence for a significant association between increased EC glutamate and decreased ipsilateral epileptogenic hippocampal volume in TLE. Future work will be needed to determine whether the increase in glutamate has a causal relationship with hippocampal atrophy, or whether another, yet unknown factor results in both. This work has implications for the understanding and treatment of epilepsy as well as other neurodegenerative disorders associated with hippocampal atrophy.
Language lateralization in temporal lobe epilepsy using functional MRI and probabilistic tractography
Authors: Rodrigo Sebastian , Oppenheim Catherine , Chassoux Francine , Hodel Jérôme , De Vanssay Aimée , Baudoin‐Chial Sonia , Devaux Bertrand , Meder Jean‐François
Published: April 2008

Summary

Purpose: Language functional magnetic resonance imaging (fMRI) is used to noninvasively assess hemispheric language specialization as part of the presurgical work‐up in temporal lobe epilepsy (TLE). White matter asymmetries on diffusion tensor imaging (DTI) may be related to language specialization as shown in controls and TLE. To refine our understanding of the effect of epilepsy on the structure–function relationships, we focused on the arcuate fasciculus (ArcF) and the inferior occipitofrontal fasciculus (IOF) and tested the relationship between DTI‐ and fMRI‐based lateralization indices in TLE.

Methods: fMRI with three language tasks and DTI were obtained in 20 patients (12 right and 8 left TLE). The ArcF, a major language‐related tract, and the IOF were segmented bilaterally using probabilistic tractography to obtain fractional anisotropy (FA) lateralization indices. These were correlated with fMRI‐based lateralization indices computed in the inferior frontal gyrus (Pearson's correlation coefficient).

Results: fMRI indices were left‐lateralized in 16 patients and bilateral or right‐lateralized in four. In the ArcF, FA was higher on the left than on the right side, reaching significance in right but not in left TLE. We found a positive correlation between ArcF anisotropy and fMRI‐based lateralization indices in right TLE (p < 0.009), but not in left TLE patients. No correlation was observed for the IOF.

Conclusions: Right TLE patients with more left‐lateralized functional activations also showed a leftward‐lateralized arcuate fasciculus. The decoupling between the functional and structural indices of the ArcF underlines the complexity of the language network in left TLE patients.
Inactivation of parvovirus B19 during STIM‐4 vapor heat treatment of three coagulation factor concentrates
Authors: Berting Andreas , Modrof Jens , Unger Ulrike , Gessner Matthias , Klotz Andreas , Poelsler Gerhard , Kreil Thomas R.
Published: April 2008

BACKGROUND: To enhance the viral safety margins, nanofiltration has been widely integrated into the manufacturing process of plasma‐derived medicinal products. Removal of smaller agents such as parvovirus B19 (B19V) by filtration, however, is typically less efficient. Because recent investigations have demonstrated that B19V may be more heat sensitive than animal parvoviruses, the potential B19V inactivation by a proprietary vapor heating procedure (STIM‐4) as incorporated into the manufacturing processes of several nanofiltered coagulation factor concentrates was investigated.

STUDY DESIGN AND METHODS: An infectivity assay based on quantitative reverse transcription–polymerase chain reaction (TaqMan, Applied Biosystems) detection of B19V mRNA after inoculation of a permissive cell line (UT7 Epo S1 cells) was used to investigate the virus inactivation capacity of the STIM‐4 vapor heat treatment as used during the manufacture of nanofiltered second‐generation Factor VIII inhibitor‐bypassing activity (FEIBA), F IX complex, and FVII products.

RESULTS: In contrast to animal parvoviruses, both B19V genotypes investigated, that is, 1 and 2, were shown to be surprisingly effectively inactivated by the STIM‐4 vapor heat treatment process, with mean log reduction factors of 3.5 to 4.8, irrespective of the product intermediate tested.

CONCLUSION: The newly demonstrated effective inactivation of B19V by vapor heating, in contrast to the earlier used animal parvoviruses, results in significant B19V safety margins for STIM‐4–treated coagulation factor concentrates.
An Employer Analysis of Managed Care Costs and Satisfaction: Process, Effects, and Policy
Authors: Carter Richard B. , Power Mark L. , Morin Michelle
Published: April 2008

ABSTRACT: Do managed care health plans truly control costs more effectively than nonmanaged care plans? Recent evidence suggests that employees are getting used to the managed care idea and that managed care is responsible for the sharp slowdown in health‐care costs. This article examines recent changes in the delivery, financing, and consumption of health care from the perspective of a large multiple‐site American corporation to see whether its health‐care costs are controlled and whether this control occurs at the expense of employee satisfaction. A unique aspect of this study is that managed care was implemented more slowly and in phases at one of the six sites analyzed. The results suggest the following. First, the Study Corporation's health‐care costs have not significantly increased four years following the change from an indemnity to a managed care plan. The authors interpret this result to mean that managed care has controlled costs because before the change, plan costs were increasing 15 percent per year. Second, the site with the underdeveloped network did not have higher costs than the other sites based on the analysis. Third, the authors show that employee satisfaction increased after implementation of the managed care plan. Moreover, satisfaction was higher at sites with more employees, higher usage, and higher health‐care costs. Last, the results suggest that plan participant satisfaction increases as the managed care network becomes more developed. Policy and benefit manager recommendations are made on the basis of these reported findings.
Using a Modified DuPont System of Analysis for Understanding Property‐Liability Insurance Company Financial Performance
Authors: Smith Barry D.
Published: April 2008

ABSTRACT: The DuPont system of equations has been used for many years when performing financial analysis on corporate financial statements. It has not been used, however, for analyzing property‐liability insurance company performance. This article shows that, with minor modifications, the DuPont system can be applied to the analysis of property‐liability insurance companies. It aids in understanding the relationship between underwriting operations and investment results and illuminates the role played by the interaction of assets, premiums, and surplus. The author hopes that the modified DuPont system presented in the article can become a standard for performing financial analysis of property‐liability insurance companies.
Managed Mental Health Care: Stakeholder Effects and Policy Implications
Authors: Ambrose Jan M. , Doerpinghaus Helen I.
Published: April 2008

ABSTRACT: During the past several years, healthcare delivery in the United States has shifted from a primarily fee‐for‐service system toward managed care. Mental health care has been affected disproportionately by this trend. The existing literature on managed mental health care is abundant, but narrowly focused. The purpose of this study is to take a broader public‐policy approach, considering simultaneously the effects on system stakeholders: patients, providers, employers, insurers, and society.
An Analysis of Disaster Risk Management Practices in the u.s. and Singapore
Authors: Christner Ron , Yee Wah Chin
Published: April 2008

ABSTRACT: This study outlines the framework of the Disaster Recovery Planning (DRP) process and describes the key steps in preparing a DRP. It also identifies the essential characteristics and core elements of the DRP and highlights the critical success factors. It provides a recommendation on the process of DRP that companies can adopt, to help them prepare a comprehensive, well‐documented, and cost‐effective DRP that is workable. Survey data are used to find out whether DRP is widely practiced in Singapore and the U.S. The survey questions aim to identify the various DRP arrangements an organization has when a disaster strikes and the provisions that are included in its general contingency plan, if any. The survey results for the two countries are analyzed to evaluate why the level of DRP differs so greatly between the U.S. and Singapore.
The Optimized V‐V Interval Determined by Interventricular Conduction Times Versus Invasive Measurement by LVdP/dtMAX
Authors: VAN GELDER BERRY M. , MEIJER ALBERT , BRACKE FRANK A.
Published: April 2008

Introduction:
We compared the calculated optimal V‐V interval derived from intracardiac electrograms (IEGM) with the optimized V‐V interval determined by invasive measurement of LVdP/dtMAX.

Methods and Results:
Thirty‐two patients with heart failure (six females, ages 68 ± 7.8 years) had a CRT device implanted. After implantation of the atrial, right and a left ventricular lead, the optimal V‐V interval was calculated using the QuickOpt™ formula (St. Jude Medical, Sylmar, CA, USA) applied to the respective IEGM recordings (V‐VIEGM), and also determined by invasive measurement of LVdP/dtMAX (V‐VdP/dt).

The optimal V‐VIEGM and V‐VdP/dt intervals were 52.7 ± 18 ms and 24.0 ± 33 ms, respectively (P = 0.017), without correlation between the two. The baseline LVdP/dtMAX was 748 ± 191 mmHg/s. The mean value of LVdP/dtMAX at invasive optimization was 947 ± 198 mmHg/s, and at the calculated optimal V‐VIEGM interval 920 ± 191 mmHg/s (P < 0.0001). In spite of this significant difference, there was a good correlation between both methods (R = 0.991, P < 0.0001). However, a similarly good correlation existed between the maximum value of LVdP/dtMAX and LVdP/dtMAX at a fixed V‐V interval of 0 ms (R = 0.993, P < 0.0001), or LVdP/dtMAX at a randomly selected V‐V interval between 0 and +80 ms (R = 0.991, P < 0.0001).

Conclusion: Optimizing the V‐V interval with the IEGM method does not yield better hemodynamic results than simultaneous BiV pacing. Although a good correlation between LVdP/dtMAX determined with V‐VIEGM and V‐VdP/dt can be constructed, there is no correlation with the optimal settings of V‐V interval in the individual patient.
The Influence of Sb2O3Addition on the Properties of Low‐melting ZnO–P2O5Glasses
Authors: Zhang Bing , Chen Qi , Song Li , Li Huiping , Hou Fengzhen
Published: April 2008

The influence of 0–16 mol% Sb2O3substitution for P2O5on the properties of ZnO–P2O5glasses has been investigated. It was shown that Sb2O3could participate in the glass network and thermal stability of the glasses decreased with increasing Sb2O3content. Glass transition temperatureTg, softening temperatureTs, and water durability all decreased firstly (up to 6 mol% Sb2O3added) and then increased. Substitution of 12 mol% Sb2O3led to a 16°C decrease inTgand 30°C decrease inTs, and weight loss of the glass was only 0.42 mg/cm2, which is ∼11 times lower than that of the glass without Sb2O3after immersion in deionized water at 90°C for 1 day. The glass containing 12 mol% Sb2O3might be a substitute for Pb‐based glasses in some applications.
The Utility of R‐Curves for Understanding Fracture Toughness‐Strength Relations in Bridging Ceramics
Authors: Kruzic J. J. , Satet R. L. , Hoffmann M. J. , Cannon R. M. , Ritchie R. O.
Published: April 2008

The mechanical behavior of four rare earth (RE)‐Mg‐doped Si3N4 ceramics (RE=La, Lu, Y, Yb) with varying grain‐boundary adhesion has been examined with emphasis on materials containing La and Lu (which represent the extremes of RE ionic radius). Fracture‐resistance curves (R‐curves) for all ceramics rose very steeply initially, giving them exceptional strength and relative insensitivity to flaw size. The highest strength was seen in the Lu‐doped material, which may be explained by its steeper initial R‐curve; the highest “apparent” toughness (for fracture from millimeter‐scale micronotches) was seen in the lowest strength La‐doped material, which may be explained by its slowly rising R‐curve at longer crack lengths. Excellent agreement was found between the predicted strengths from R‐curves and the actual strengths for failures originating from natural flaws, a result attributed to careful estimation of the early part of the R‐curve by deducing the intrinsic toughness, K0, and the fact that this portion of the R‐curve is relatively insensitive to sample geometry. Finally, it was found that RE elements with relatively large ionic radius (e.g., La) tended to result in lower grain‐boundary adhesion. This implies that there is a small window of optimal grain‐boundary adhesion which can lead to the fastest rising R‐curves (for short cracks) and the highest strengths. The importance of this work is that it reinforces the notion that factors which contribute to the early part of the R‐curve are critical for the design of ceramic microstructures with both high strength and high toughness.
Similarity in Gender and Self‐Esteem for Supportive Peer Relationships: The Mediating Role of Cooperative Goals1
Authors: Chen Yi‐Feng Nancy , Huang Xu , Tjosvold Dean
Published: April 2008

The present study investigated whether cooperative goals mediate the relationship between similarity in gender and self‐esteem and social support and relationship quality in ongoing peer dyads. Based on data collected from 209 student dyads, the findings largely support the mediating role of cooperative goals. However, the study found that gender similarity was positively related while self‐esteem similarity was negatively related to cooperative goals and relationship quality of peer dyad members.
A Door to HIV‐Prevention Interventions: How Female‐Targeted Materials Can Enhance Female Participation1
Authors: Mc Culloch Kathleen C. , Albarracín Dolores , Durantini Marta R.
Published: April 2008

The aim of this study was to examine the influence of gender on exposure to gender‐tailored HIV‐prevention brochures. During an unobtrusive observation of participants' reading of brochures, both men and women were likely to avoid gender‐mismatched brochures. However, women were more likely to selectively approach gender‐matched brochures over gender‐neutral brochures than were men. Furthermore, exposure to the female‐targeted brochure predicted accepting an HIV‐prevention video. This pattern was only the case for females and not for males or for the male‐targeted brochure. This finding implies that the gender‐tailored brochures are more useful for women than for men, and may open the door to other materials designed with preventive objectives.
Perceived Legitimacy of a Promotion Decision in Relation to Deservingness, Entitlement, and Resentment in the Context of Affirmative Action and Performance1
Authors: Feather N. T.
Published: April 2008

This study tests a model relating perceived legitimacy of a promotion committee's decision to the deservingness and entitlement of a male or female candidate for promotion and to resentment about the decision. University students responded to scenarios in which deservingness was manipulated by information about the quality of the candidate's performance; entitlement was manipulated by information about an affirmative‐action policy. Results showed strong positive effects of perceived deservingness on perceived legitimacy, which were partially mediated by resentment. Perceived entitlement was also a positive predictor of perceived legitimacy. Gender bias occurred, especially in regard to resentment and when the male candidate was promoted. The study extends deservingness theory to a new area and provides evidence for the distinction between deservingness and entitlement.
Le renouveau de l'inspection du travail dans le monde latin
Authors: PIORE Michael J. , SCHRANK Andrew
Published: April 2008

Les auteurs examinent le rôle de l'inspection du travail dans un contexte de renouveau réglementaire. Ils distinguent le modèle latin – qui laisse aux inspecteurs la latitude d'ajuster leurs décisions à la situation de l'entreprise – de l'approche bien moins souple quiprévaut aux Etats‐Unis. Le premier concilie réglementation et flexibilité, mais comporte un risque d'arbitraire ou d'incohérences. Les inspecteurs pour‐raient être les troupes d'élite dans la bataille pour le travail décent si l'on prévient ces risques par la gestion de la culture d'entreprise, l'explicitation systématique des connaissances tacites quifondent leurs décisions et un approfondissement des recher‐ches sur les relations entre normes du travail et pratiques des entreprises.
Fixation du salaire minimum dans les pays en développement: carences et remèdes
Authors: SAGET Catherine
Published: April 2008

Il est notoire que, dans une forte minorité de pays en développement, le salaire minimum est soit excessivement bas, soit excessivement élevé. L'auteur propose plusieurs méthodes de mesure en vue de comparer le niveau de ce salaire d'un pays à l'autre. Elle cherche ensuite à savoir si ce salaire minimum est effectif, c'est‐à‐dire s'il joue vraiment son rôle de salaire plancher sur le marché du travail. Elle examine ensuite les facteurs institutionnels qui expliquent ces valeurs extrêmes et conclut en suggérant des solutions pour fixer le salaire minimum à un niveau plus approprié et plus significatif.
Le modèle social de l'Europe méridionale: changement et continuité
Authors: KARAMESSINI Maria
Published: April 2008

Ces dernières décennies, tous les aspects du modèle social de l'Europe méridionale ont connu de profonds changements. L'évolution de la législation relative aux relations professionnelles, à la fixation des salaires et à la protection de l'emploi a contribuéà accroître la flexibilité salariale et du travail, et à limiter la segmentation du marché du travail. L'évolution du système de protection sociale a viséà améliorer les qualifications de la main‐d'æuvre, à combler les lacunes de la protection sociale, à réduire les inégalités de la sécurité sociale et à contenir la hausse des dépenses sociales. Les changements institutionnels n'ont pas supprimé les principales caractéristiques du modèle, à savoir une segmentation du marché du travail et un familialisme marqués, mais la grève des naissances laisse entrevoir les limites du familialisme dans un proche avenir.
Toward managed flexibility: The revival of labour inspection in the Latin world
Authors: PIORE Michael J. , SCHRANK Andrew
Published: April 2008

Examining the role of labour inspection in the context of the revival of labour market regulation, the authors distinguish between the Latin model, where inspectors have authority to tailor enforcement to firms' exigencies, and the less flexible United States approach. The Latin model can reconcile regulation with economic flexibility and transform inspectors into the shock troops of a campaign for decent work. But its vulnerability to arbitrary behaviour on their part needs to be addressed through: management of organizational cultures; exposure and sys‐tematization of the tacit knowledge underpinning inspectors' judgements; and research into the relationship between labour standards and business practices.
Fixing minimum wage levels in developing countries: Common failures and remedies
Authors: SAGET Catherine
Published: April 2008

Some developing countries have set their minimum wages too high or too low to constitute a meaningful constraint on employers. The article compares minimum wages worldwide, proposes several ways of measuring them in developing countries and discusses whether they are effective thresholds in those countries. The second part of the article considers the institutional factors leading countries to set minimum wages at extreme levels. The author concludes that the minimum wage is used as a policy instrument to several ends – wage negotiation, deflation and social dialogue – which results in the absence of a wage floor, weak collective bargaining, or non‐compliance.
Continuity and change in the southern European social model
Authors: KARAMESSINI Maria
Published: April 2008

Over the past 20 years or so, the southern European model has undergone substantial change in every way. The changes in industrial relations, wage‐setting and employment protection legislation have tended to increase wage and labour flexibility and restrict labour market segmentation. Changes within the welfare state have sought to improve labour force skills, fill gaps in social protection, reduce inequalities in social security and contain social expenditure growth. Yet institutional change has not eliminated the main features of this model: pronounced labour market segmentation and familialism; however, extremely low fertility rates are indicative of the limits of familialism in the near future.
Progressive silencing of p14ARF in oesophageal adenocarcinoma
Authors: Huang Yinghui , Peters Christopher J. , Fitzgerald Rebecca C. , Gjerset Ruth A.
Published: April 2008

The frequency of oesophageal adenocarcinoma is increasing in Western countries for unknown reasons, and correlates with a corresponding increase in the pre‐malignant condition, Barrett's Oesophagus, which raises the risk of adenocarcinoma by some 40‐ to 125‐fold. We have examined how disease progression correlates with changes in expression of the p14ARF (ARF) tumour suppressor, a key regulator of the p53 tumour suppressor pathway that is silenced in some 30% of cancers overall, but for which a role in oesophageal cancer is unclear. We have used quantitative PCR, RT‐PCR, methylation‐specific PCR and chromatin‐immunoprecipitation to examine the regulation and function of ARF in oesophageal adenocarcinoma tissue specimens and cell lines. We find highly significant reductions (P< 0.001) in ARF expression during disease progression from normal oesophageal epithelium to Barrett's Oesophagus to adenocarcinoma, with 57/76 (75%) adenocarcinomas displaying undetectable levels of ARF expression. Retention of ARF expression in adenocarcinoma is a highly significant indicator of increased survival (P< 0.001) and outperforms all clinical variables in a multivariate model. CpG methylation as well as histone H3 methylation of lysines 9 and 27 contribute independently to ARF gene silencing in adenocarcinoma cell lines and can be reversed by 5‐aza‐2′‐deoxycytidine. The results suggest that silencing of ARF is involved in the pathogenesis of oesophageal adenocarcinoma and show that either DNA or histone methylation can provide the primary mechanism for ARF gene silencing. Silencing of ARF could provide a useful marker for increased risk of progression and poor prognosis.
Endothelial cells from cord blood CD133+CD34+ progenitors share phenotypic, functional and gene expression profile similarities with lymphatics
Authors: Nguyen Van Anh , Fürhapter Christina , Obexer Petra , Stössel Hella , Romani Nikolaus , Sepp Norbert
Published: April 2008

The existence of endothelial progenitor cells (EPC) with high cell‐cycle rate in human umbilical cord blood has been recently shown and represents a challenging strategy for therapeutic neovascularization. To enhance knowledge for future cellular therapy, we compared the phenotypic, functional and gene expression differences between EPC‐derived cells generated from cord blood CD34+ cells, and lymphatic and macrovascular endothelial cells (EC) isolated from human foreskins and umbilical veins, respectively. Under appropriate culture conditions, EPC developed into fully matured EC with expression of similar endothelial markers as lymphatic and macrovascular EC, including CD31, CD36, von Willebrand factor FVIII, CD54 (ICAM‐1), CD105 (endoglin), CD144 (VE‐cadherin), Tie‐1, Tie‐2, VEGFR‐1/Flt‐1 and VEGFR‐2/Flk‐1. Few EPC‐derived cells became positive for LYVE‐1, indicating their origin from haematopoietic stem cells. However they lacked expression of other lymphatic cell‐specific markers such as podoplanin and Prox‐1. Functional tests demonstrated that the cobblestone EPC‐derived cells up‐regulated CD54 and CD62E expression in response to TNF‐α, incorporated DiI‐acetylated low‐density liproprotein and formed cord‐ and tubular‐like structures with capillary lumen in three‐dimensional collagen culture – all characteristic features of the vascular endothelium. Structures compatible with Weibel‐Palade bodies were also found by electron microscopy. Gene microarray profiling revealed that only a small percentage of genes investigated showed differential expression in EPC‐derived cells and lymphatic EC. Among them were adhesion molecules, extracellular matrix proteins and cytokines. Our data point to the close lineage relationship of both types of vascular cells and support the theory of a venous origin of the lymphatic system.
Development of a novel antimicrobial peptide, AG‐30, with angiogenic properties
Authors: Nishikawa Tomoyuki , Nakagami Hironori , Maeda Akito , Morishita Ryuichi , Miyazaki Nobuhiko , Ogawa Toshihiro , Tabata Yasuhiko , Kikuchi Yasushi , Hayashi Hiroki , Tatsu Yoshiro , Yumoto Noboru , Tamai Katsuto , Tomono Kazunori , Kaneda Yasufumi
Published: April 2008

The utility of various synthetic peptides has been investigated in clinical trials of the treatment of cancers, infectious diseases and endocrine diseases. In the process of functional gene screening with in silico analysis for molecules with angiogenic properties, we generated a small peptide, angiogenic peptide (AG)‐30, that possesses both antimicrobial and pro‐inflammatory activities. AG‐30 has an α‐helix structure with a number of hydrophobic or net positively charged amino acids and a propensity to fold into amphipathic structures. Indeed, AG‐30 exhibited antimicrobial activity against various bacteria, induced vascular endothelial cell growth and tube formation in a dose‐dependent manner and increased neovascularization in a Matrigel plug assay. As a result, AG‐30 up‐regulated expression of angiogenesis‐related cytokines and growth factors for up to 72 hrs in human aortic endothelial cells. To further evaluate the angiogenic effect of AG‐30 in vivo, we developed a slow‐release AG‐30 system utilizing biodegradable gelatin microspheres. In the ischaemic mouse hind limb, slow‐release AG‐30 treatment results in an increase in angiogenic score, an increase in blood flow (as demonstrated by laser Doppler imaging) and an increase in capillary density (as demonstrated by immunostaining with anti‐CD31 antibody). These data suggest that the novel peptide, AG‐30, may have therapeutic potential for ischaemic diseases.
Electron tomography and immunonanogold electron microscopy for investigating intracellular trafficking and secretion in human eosinophils
Authors: Melo Rossana C. N. , Dvorak Ann M. , Weller Peter F.
Published: April 2008

Electron tomography (ET) has increasingly been used to understand the complexity of membrane systems and protein‐trafficking events. By ET and immunonanogold electron microscopy, we recently defined a route for vesicular transport and release of granule‐stored products from within activated human eosinophils, cells specialized in the secretion of numerous cytokines and other proteins during inflammatory responses. Here, we highlight these techniques as important tools to unveil a distinct eosinophil vesicular system and secretory pathway.
Improving the quality of clinical teaching in a restorative clinic using student feedback
Authors: Youngson Callum , Fox Kathryn , Boyle Edward , Blundell Katherine , Baker Robert
Published: April 2008

Introduction:  A large proportion of the undergraduate curriculum is spent within Restorative Dentistry at the University of Liverpool. As well as supportive “phantom head” courses the undergraduates receive significant amounts of teaching within the clinics themselves. In 2004, to help inform the clinical tutors as to their areas of strengths and weaknesses, undergraduates were invited to complete an anonymous questionnaire on the quality of teaching they received from their clinical supervisors. This process has been repeated subsequently in 2005 and 2006.

Method:  A 19 parameter questionnaire, employing a 5‐point Likert scale and space for open comments, was circulated to every clinical undergraduate student. Questionnaires were returned anonymously and all data collected by one researcher. Descriptive statistical analysis was performed and the staff provided with individual feedback within the context of the overall departmental profile. The pooled data from each of the years was then compared to determine if any changes had occurred. Statistical analysis used Kruskal Wallis tests to determine whether these were statistically significant.

Results:  Although the range varied, median scores of 4 (agree) were gained for each question each year. Following statistical analysis 18 of the parameters showed a statistically significant improvement (P < 0.05) between 2004 and 2006 with only one remaining constant throughout.

Conclusion:  It would appear that the use of a questionnaire based feedback system can result in a tangible and demonstrable improvement in the delivery of clinical teaching.
Gene expression profiling of Polycomb, Hox and Meis genes in patients with acute myeloid leukaemia
Authors: Grubach Lykke , Juhl‐Christensen Caroline , Rethmeier Anita , Olesen Lene Hyldahl , Aggerholm Anni , Hokland Peter , Østergaard Mette
Published: April 2008

The Polycomb group (PcG) of genes is important for differentiation and cell‐cycle regulation and is aberrantly expressed in several cancers. To analyse the role of deregulated PcG genes in acute myeloid leukaemia (AML), we determined by RQ‐PCR the expression of the PcG genes BMI‐1, MEL18, SCML2, YY1 and EZH2, and the downstream PcG targets HOXA4, HOXA9 and MEIS1 in diagnostic bone marrow samples from 126 AML patients. There was a general overexpression of the genes in AML patients compared to 20 healthy donors, except of HOXA4 and MEL18, which both displayed a wide range of expression levels within the AML subgroups. Among the AML patients with normal karyotype, a low HOXA4 level was associated with a shorter overall survival (P = 0.005). In addition, expression levels of MEL18 and EZH2 were significantly (P < 0.025) higher in patients with complex karyotype and lower in CBF‐mutated patients. The t(8;21) vs. inv(16) positive patients showed significantly different expression of SCML2, BMI‐1, YY1, HOXA9 and MEIS1 (P ≤ 0.01). Comparisons between the PcG and PcG‐regulated genes and a number of clinical and molecular data revealed correlations to genes involved in DNA methylation (DNMT1, DNMT3B), apoptosis (BAX, CASPASE 3) and multidrug‐resistance (MDR1, MRP ) (P < 0.01). In conclusion, our data suggest that the role of PcG and PcG‐regulated genes in leukaemogenesis varies between, as well as within karyotypic subgroups.
Regression of herpes viral infection symptoms using melatonin and SB‐73: comparison with Acyclovir
Authors: Nunes Odilon da Silva , Pereira Ricardo de Souza
Published: April 2008

Abstract:  Infection with Herpes simplex virus type 1 (HSV‐1) typically causes lesions of the mouth, face, skin, esophagus, or brain. Herpes simplex virus type 2 (HSV‐2) usually causes infections of the genitals, rectum, skin, hands, or meninges. The herpes viruses are a major cause of blindness from keratitis. The usual drugs used for herpes are Vidarabine, Acyclovir, Penciclovir and Ganciclovir; they are associated with several complications. The aim of this study was to investigate if a formulation containing 2.5 mg melatonin and 100 mg SB‐73 would help patients with herpes, and to compare the preparation with 200 mg Acyclovir. SB‐73 is a mixture of magnesium, phosphate, fatty acids extracted from Aspergillus sp. which has anti‐herpes virus properties. A single blind randomized study was performed in which 70 patients underwent treatment using the supplement cited above (group A) and 75 received treatment of 200 mg Acyclovir (group B). Sixty‐seven patients of the group A (95.7%) reported a complete regression of symptoms after 7 days of treatment. By comparison, 64 subjects (85.3%) of the Acyclovir reported regression of symptoms in the same period. There was statiscally significant difference between the groups (P < 0.05).
Alteration of skin mechanics by thin polymer films
Authors: Jachowicz Janusz , McMullen Roger , Prettypaul Donald
Published: April 2008

Background/purpose: High molecular weight polymers such as proteins and polysaccharides have been commonly employed in cosmetic practice to induce skin tightness. The effect is perceived by users as an increase in skin tightness (firmness) accompanied by skin smoothing and elimination of wrinkles and lines. The aim of the study was to assess whether high molecular weight synthetic polymers, in the form of simple skin treatment formulations, could modify mechanical properties of natural skin as well as artificial skin models.

Methods: In experiments involving natural skin, the formulations were employed to treat the inner forearm of five panelists, who ranged in age from mid‐20s to mid‐40s. Indentometric analysis also included rubber skin models, with various viscoelastic characteristics, modified by deposition of thin polymer films on the surface. Polymers such as polyvinylpyrrolidone, polyquaternium‐55, polyimide‐1, VP/acrylates/lauryl methacrylate copolymer, and sodium alginate were investigated. The effects of the products were quantified by mechanical skin indentation performed at small deformations. Data analysis was performed using the Hertz theory of contact mechanics, which included the calculation of fundamental parameters such as the modulus of elasticity.

Results: The indentometric analysis revealed an increase in the Young's modulae for both artificial and natural skin as a result of treatment with the polymers. The effect was dependent on the amount of deposited product, which was varied in the range from 0.053 to 1.06 mg/cm2 of polymer. The observed increases in Young's modulae were typically from about 0.7 to 1.4 × 104 N/m2 for untreated skin to 1.4–2.0 × 104 N/m2 for polymer‐modified skin, depending on the polymer structure (molecular weight) and the amount of deposition. By the analysis of artificial skin models, it was found that the magnitude of stiffening depends on the mechanical characteristics of the base material. Softer skin models displayed larger increases in Young's modulus after polymer treatment than stiffer skin models. Also, the analysis of skin models suggested that polymeric treatments can lower the viscoelasticity of skin as demonstrated by decreased values of hysteresis loss factors calculated from indentation force vs. penetration depth plots. The performance of the polymers was also shown to be dependent on ambient humidity with the most hygroscopic materials loosing their stiffening effect at high humidity.

Conclusions: The data indicate that high molecular weight polymers can be useful as skin stiffening, firming, or tightening agents. This was demonstrated by indentometric, mechanical analysis of natural skin and artificial skin models, and by determining Young's modulae and viscoelastic parameters.
Elementary school staff knowledge about dental injuries
Authors: McIntyre Judy D. , Lee Jessica Y. , Trope Martin , Vann William F.
Published: April 2008

Abstract –  Elementary school staff can play a crucial role in managing traumatic dental injuries (TDIs) because they are often in proximity to children and are frequently called upon to assist with children’s accidents. International studies reveal that elementary school personnel have little knowledge about emergency dental care and management. The purpose of this study was to assess the knowledge, practice and experience regarding TDIs among a sample of elementary school personnel in the USA. Assessment was performed using a demographic questionnaire and a newly developed TDI survey instrument. Results revealed a wide distribution of responses. Overall, dental trauma knowledge among this group was poor. The majority of respondents were not well‐versed regarding TDIs, their management, the benefits of timely care or treatment costs. However, staff reported a keen interest in receiving more TDI information and training. TDI education and management are needed among all elementary school staff members to improve the prognosis of these accidents when they occur.
Evaluating Emdogain® and healing of replanted teeth using an intra‐individual experimental–control study design
Authors: Fridström Margareta , Schollin Jens , Crossner Claes‐Göran
Published: April 2008

Abstract –  The purpose of the present investigation was to use an intra‐individual experimental–control study design to explore if application of Emdogain® prior to re‐plantation after a dry extra‐alveolar period of 60 min would promote a favorable healing of the periodontal ligament cells. Ten patients, for whom already decisions had been taken to extract two maxillary premolars because of crowding, participated in the study. The teeth were extracted and endodontic treatment was performed extra orally. The experimental tooth and its alveolar socket were covered with Emdogain® prior to replantation. The contra lateral tooth served as a control and was replanted without any prior treatment. The teeth were stabilized with a retainer for 3–7 days and the patients were followed up every third week. After 13 weeks, the teeth were finally extracted and prepared for histological examination. Radiographs were taken before the study period, at day 29 and prior to the final extraction. The results were in favor of Emdogain®, but the overall difference between the Emdogain®‐treated tooth and its control was rather small, and it seemed questionable if the registered differences could be of any obvious practical clinical importance. Histologically, all the teeth showed some degree of pathology after such a long dry extra‐oral time and the outcome seemed to be more correlated to the individual than to the treatment. Given more favorable conditions regarding storage medium and/or extra‐oral time, Emdogain® might still be of value for an uncomplicated healing after replantation.