bluuebunny/crossref_metadata_2025 huggingface dataset:
Meta‐analysis of the timing of haemorrhage after tonsillectomy: an important factor in determining the safety of performing tonsillectomy as a day case procedure
Authors: Bennett A.M.D. , Clark A.B. , Bath A.P. , Montgomery P.Q.
Published: September 2005

Objectives:  To perform a meta‐analysis of studies of the timing of primary tonsillectomy haemorrhage. In particular to compare the difference in risk between 0–8 and 8–24 h; that is whether overnight inpatient tonsillectomy is required.

Design:  Medline search of all tonsillectomy studies to perform a meta‐analysis of the timing of primary haemorrhages.

Setting:  Literature‐based study.

Participants:  All adult and paediatric tonsillectomy studies giving the absolute number and timing of all primary haemorrhages.

Main outcome measures:  The overall incidence of haemorrhage occurring between 0–8 and 8–24 h. The overall incidence of haemorrhage for each of the first 24 h after operation. Compare risk of a bleed occurring 0–8, 8–24 and >24 h where data were available.

Results:  From a 1.4% overall risk of a primary haemorrhage only one in 14 occur after 8 h, i.e. 0.1% (95% CI = 0.08–0.16%). A total of 833 patients would require to be kept overnight in order to identify one case of bleeding after 8 h.

Conclusions:  Little benefit was conferred from overnight admission from the point of view of monitoring for primary haemorrhage. A case can be made for either day‐case tonsillectomy (hospital stay over the period in which 93% of primary haemorrhages would occur) or the ‘belt‐and‐braces’ approach of a 1‐week stay (during which all haemorrhages would occur) but current 24‐h admission appears illogical.
Predictors of speech and swallowing function following primary surgery for oral and oropharyngeal cancer
Authors: Zuydam A.C. , Lowe D. , Brown J.S. , Vaughan E.D. , Rogers S.N.
Published: September 2005

Objectives:  To examine the association between the speech and swallowing aspect of health‐related quality of life (HRQOL) and selected clinical parameters, and particularly to determine those that are predictive of good outcomes at 1 year after surgery.

Design:  Prospective questionnaire and clinical study.

Setting:  Regional Maxillofacial Unit.

Participants:  A total of 278 consecutive patients undergoing primary surgery for squamous cell carcinoma between 1995 and 1999. HRQOL was assessed using the University of Washington Quality of Life questionnaire (UW‐QOL) pre‐surgery, and post‐surgery at 6 months, 1 year and later (median 39 months).

Main outcome measures:  Presentation of results was mainly descriptive, involving percentages and mean scores. Association of clinico‐demographic factors with tumour site, and with UW‐QOL swallowing and speech after 12 months, was tested with Fisher's exact or chi‐squared tests as appropriate and modelled using logistic regression methods.

Results:  Univariate relationships were seen between speech and swallowing scores and with tumour size, T staging, radiotherapy, type of surgery (primary closure or free tissue transfer), tumour site, extent of resection of posterior tongue and soft palate, and UW‐QOL taste and saliva scores. Multiple logistic regression showed that no radiotherapy (P < 0.001) and primary surgical closure/laser surgery (P = 0.003) were the main predictors of good swallowing, and primary surgical closure/laser surgery was the main predictor of good speech (P < 0.001) at 1 year.

Conclusions:  A number of clinical parameters can influence the speech and swallowing aspect of quality of life in these patients and when feasible, primary closure results in a better outcome than free flap reconstruction.
Screening for distant metastases in patients with head and neck cancer: what is the current clinical practice?
Authors: Brouwer J. , de Bree R. , Hoekstra O.S. , Langendijk J.A. , Castelijns J.A. , Leemans C.R.
Published: September 2005

Objectives:  The detection of distant metastases during screening influences the choice of treatment in patients with head and neck squamous cell carcinoma (HNSCC). There is no consensus on the diagnostic technique that has to be used nor on the subgroup of HNSCC patients that may benefit from screening.

Design:  Questionnaire on current practice concerning the diagnostic work‐up in HNSCC patients for screening for distant metastases.

Participants:  Investigators in the 12 otolaryngology / head and neck and seven oromaxillofacial departments treating head and neck cancer in the Netherlands.

Results:  The response rate was 100%. Indications for screening were cervical lymph node metastases (63%), mutilating surgery (58%), locoregional recurrence (47%), advanced T‐stage (32%), second primary tumour (21%). Diagnostic techniques routinely used for screening besides chest X‐ray were chest CT (84%), liver ultrasound (53%), liver CT (16%) and bone scintigraphy (42%). Forty‐two per cent of the clinicians were not satisfied with the current methods of screening.

Conclusion:  This survey shows a substantial variation in indications and diagnostic techniques used for screening for distant metastases between the major institutions treating head and neck cancer in the Netherlands. There is a need for guidelines for screening for distant metastases in patients with head and neck cancer.
Variability in nomenclature of benign laryngeal pathology based on video laryngoscopy with and without stroboscopy
Authors: Chau H.N. , Desai K. , Georgalas C. , Harries M.
Published: September 2005

Objectives:  To assess the extent of interobserver variability in the nomenclature of benign laryngeal pathology based on evaluation of video‐endoscopies with and without stroboscopy.

Design:  Eight video clips of benign laryngeal conditions were viewed by 35 non‐voice specialist ENT surgeons. The surgeons viewed the clips in groups of varying sizes with no discussion between them and were asked to make only one diagnosis for each lesion.

Setting:  Specialist voice clinic in the department of ENT at The Royal Sussex County Hospital in Brighton, UK.

Participants:  Participating ENT surgeons were all either registrars or consultants working at different centres in UK, recruited by the author. None were voice specialists.

Main outcome measure:  Interobserver agreement was measured using kappa statistics.

Results:  Variation was widespread with only two of the eight cases (25%) showing agreement of over 75%. Agreement could be analysed statistically as moderate at best (κ = 0.5 with a 95% confidence interval from 0.5 to 0.6). The seniority of the laryngologist was also analysed with consultants and senior trainees (specialist registrar years 4–6) having better agreement than junior trainees (specialist registrar years 1–3).

Conclusions:  The generally accepted optimum treatment for different benign laryngeal pathologies varies substantially. However, our results shows a significant high‐level interobserver variability in their diagnosis by non‐voice specialists, thus reducing the reliability of outcome data and treatment recommendations. It is therefore important to try and lower this interobserver variability, possibly by widespread use of improved diagnostic technology, stricter/more universally accepted definitions and supervised training of junior doctors in a voice clinic environment.
Guidelines in head and neck oncology compliance and consequences of deviations from the standard protocol for tongue and floor of mouth squamous carcinoma
Authors: Aarts M.C.J. , Hogen Esch T.T. , Terhaard C.H.J. , Koole R. , Hordijk G.J.
Published: September 2005

Objectives:  To investigate the extent of violation of a regional guideline for the treatment of patients with carcinoma of the tongue/floor of mouth (ICD0 C02, C04). Different aspects of protocol violation (i.e. undertreatment or overtreatment) and consequences for treatment outcome were evaluated.

Design:  Retrospective analysis of data from medical records.

Setting:  The Department of Maxillofacial and Oral Surgery and the Department of Otorhinolaryngology and Head and Neck Surgery of the University Medical Centre Utrecht.

Participants:  A total of 217 patients treated between 1991 and 2001 for a stage II and stage III carcinoma of the tongue/floor of mouth.

Main outcome measures:  Protocol violation, tumour recurrence.

Results:  The overall adherence to the guideline was 55%. In the non‐adherence group of patients, 21% were overtreated, 71% were undertreated, and 8% were both overtreated and undertreated. There was no statistically significant difference in tumour recurrence between the two groups for stage II (P = 0.68) or stage III (P = 0.97) disease, or between undertreatment and overtreatment of patients with stage II (P = 0.47) or stage III (P = 0.90) disease.

Conclusions:  Although protocol violation occurs in as many as 45% of patients, this does not result in a worse tumour recurrence. Neither overtreatment nor undertreatment appears to affect the overall tumour recurrence.
Quantifying water‐stable soil aggregate turnover and its implication for soil organic matter dynamics in a model study
Authors: De Gryze S. , Six J. , Merckx R.
Published: September 2005

Recent studies have concluded that the dynamics of soil structure are central to the understanding of soil organic matter (SOM) cycling and the ensuing soil‐water–nutrient relationships. Aggregate turnover directly controls the stabilization and physical protection of SOM. Therefore, quantifying aggregate dynamics will improve our ability to predict SOM behaviour as affected by ecosystem management and global change. We present an approach to directly quantify aggregate dynamics using rare‐earth oxides as tracers. A 6‐week laboratory incubation was set up to measure aggregate dynamics at different times. We made samples in which each different aggregate size‐fraction contained a different tracer. By following the redistribution of these tracers into the other aggregate size‐fractions, we could quantify all soil mass transfers between aggregate size‐fractions. A comparison with a control soil showed that the tracer did not affect soil respiration or the aggregation process itself. Tracer mixing homogeneity, recovery and immobility were tested and validated. While initially macroaggregate formation occurred rapidly, microaggregate formation occurred more slowly during the experiment. Subsequent aggregate stabilization was more pronounced for the newly formed microaggregates than for the newly formed macroaggregates. Calculated turnover times were smaller for macroaggregates than for microaggregates (i.e. 30 vs. 88 days). Further research is needed to investigate to what extent these results can be extrapolated to the field. Our results confirmed existing qualitative views and concepts on aggregate dynamics in a quantitative way and will be valuable in directly linking aggregate turnover to the stabilization and protection of SOM.
The effect of water content on solid‐state 13C NMR quantitation and relaxation rates of soil organic matter
Authors: Smernik R. J.
Published: September 2005

Two hydrofluoric acid‐treated soils were prepared with water contents ranging up to 22% by exposing them to a range of atmospheric humidities. There was no effect of water content on the chemical shift distribution of nuclear magnetic resonance (NMR) signal in 13C cross‐polarization (CP) NMR spectra. The sensitivity of the 13C CP NMR spectra decreased slightly with increasing water content. Much of this decrease could be attributed to decreases in T1ρH relaxation rates, caused by enhanced molecular mobility of the organic matter in the presence of absorbed water. Rates of T1H relaxation were very sensitive to water content, and average T1H relaxation rates decreased four‐ to five‐fold from the smallest to the largest water content. Rates of T1H relaxation were non‐uniform, and were better modelled by two‐T1H component fits than one‐T1H component fits. The ratio of rapidly to slowly relaxing components increased with increasing water content. Proton spin relaxation editing (PSRE) subspectra revealed substantial changes in the nature of these two components with increasing water content. These results indicate the presence of an organic matter component that is very sensitive to water content, transforming from slowly relaxing at a small water content to rapidly relaxing at a greater water content. This component was shown to be rich in O–alkyl and carbonyl C, and may be hemicellulosic root exudates and microbial mucilages. The slowly relaxing PSRE component was a mixture of ligno‐cellulose and alkyl biopolymers, whereas the rapidly relaxing component was primarily charcoal for one of the soils, and was reminiscent of dissolved organic carbon for the other soil. These findings show that care must be taken in controlling water contents when using PSRE to study organic matter.
Dynamics and origin of the non‐hydrolysable organic fraction in a forest and a cultivated temperate soil, as determined by isotopic and microscopic studies
Authors: Poirier N. , Derenne S. , Balesdent J. , Chenu C. , Bardoux G. , Mariotti A. , Largeau C.
Published: September 2005

We isolated the non‐hydrolysable macromolecular organic fraction (insoluble fraction resistant to drastic laboratory hydrolyses) from a temperate, loamy, forest soil (Lacadée, France) and from the soil of an adjacent plot cleared 35 years ago and continuously cropped with maize. The quantitative, morphological (light, scanning and transmission electron microscopy) and isotopic (bulk δ13C, individual compound δ13C and radiocarbon dating) features of these two non‐hydrolysable fractions were determined and compared. It appeared that: (i) extensive degradation of the non‐hydrolysable material inherited from the forest soil occurred upon cropping, revealing that its resistance to drastic laboratory hydrolyses is not paralleled by a great resistance to natural biodegradation triggered by change in land use; (ii) only small inputs of maize‐derived compounds occurred in the non‐hydrolysable fraction of the cultivated soil so that, in spite of extensive degradation, the forest‐inherited carbon still predominates; (iii) the non‐hydrolysable fractions of both soils comprise the same components (wood debris, spores, pollen, and, predominantly, granular organic aggregates), which correlate with the previously identified chemical components (charcoal, aliphatic lipid components and melanoidin‐like components); (iv) the non‐hydrolysable fraction of the cropped soil shows a greater contribution of aliphatic moieties, reflecting differential degradation of the components of the non‐hydrolysable material inherited from the forest soil; (v) this degradation resulted in enrichment in the oldest components; and (vi) no relationship is observed, in the two Lacadée soils, between resistance to drastic laboratory hydrolyses, on the one hand, and stability towards biodegradation in situ, on the other. These observations, added to recent ones on other types of soils, suggest that such a conspicuous uncoupling between non‐hydrolysable and stable carbon is probably a general feature of organic matter in soil as opposed to sedimentary organic matter.
Apical membrane and junctional complex formation during simple epithelial cell differentiation of F9 cells
Authors: Komiya Satoshi , Shimizu Masayuki , Ikenouchi Junichi , Yonemura Shigenobu , Matsui Takeshi , Fukunaga Yoshitaka , Liu Huijie , Endo Fumio , Tsukita Shoichiro , Nagafuchi Akira
Published: September 2005

Epithelium formation is a common event in animal morphogenesis. It has been reported that F9 cells differentiate into visceral endoderm‐like epithelial cells when cell aggregates are cultured in the presence of retinoic acid. The present investigation set out to determine whether this in vitro model could be used under monolayer culture conditions, which is suitable for a detailed analysis of epithelial differentiation. We performed comparative gene expression analyses of F9 cells grown under aggregate and monolayer culture conditions prior to and following treatment with retinoic acid. Under these conditions, induction in the expression of differentiation marker genes was confirmed, even in monolayer cultures. Junctional complex and apical membrane formation, both of which are characteristic of epithelial cells, were also observed under monolayer culture conditions. Because of the merit of monolayer culture condition, we found that apical membrane and junctional complex formation are strictly regulated during epithelial differentiation. It was also revealed that F9 cells differentiated into epithelial cells predominantly on the fourth and fifth day following retinoic acid induction. These results showed that a monolayer culture of F9 cells represents a viable in vitro model that can be employed to elucidate mechanisms pertaining to epithelium formation.
HLA Class II molecules on haplotypes associated with type 1 diabetes exhibit similar patterns of binding affinities for coxsackievirus P2C peptides
Authors: Ellis Richard J. , Varela‐Calvino Ruben , Tree Timothy I. M. , Peakman Mark
Published: September 2005

Enteroviruses such as coxsackievirus B4 (CVB4) are proposed as possible environmental triggers or accelerants of the autoimmune process that leads to type 1 diabetes mellitus. One putative mechanism to account for this association is mimicry between virus components and islet autoantigens. Particular interest has focused on the CVB4 non‐structural protein P2C, which we previously showed to be a major target of the effector memory anti‐CVB4 CD4 T‐cell response, and which harbours a region of sequence similarity with the islet autoantigen, glutamic acid decarboxylase (GAD65). Since several distinct human leucocyte antigen (HLA) Class II molecules are associated with development of type 1 diabetes, we hypothesized that for functional mimicry to be important, any potential region(s) of mimicry in P2C should bind to each of these susceptibility molecules. In the present study therefore we examined the affinity of 20‐mer overlapping P2C peptides for soluble HLA‐DR4, ‐DR3, ‐DQ2 and ‐DQ8. We identified one discrete region of P2C with high binding affinities for all of these HLA Class II molecules. Moreover, the binding affinity of P2C peptides was significantly correlated between HLA molecules present on the same susceptibility haplotype (e.g. DR4 and DQ8, P =0·0076; DR3 and DQ2 P = 0·002). We conclude that possession of these haplotypes favours restricted presentation of viral epitopes, and speculate that this could promote the potential for mimicry between microbial proteins and islet autoantigens.
Costimulation of T‐cell proliferation by anti‐l‐selectin antibody is associated with the reduction of a cdk inhibitor p27
Authors: Nishijima Ken‐ichi , Ando Munetoshi , Sano Shusuke , Hayashi‐Ozawa Aiko , Kinoshita Yoshinori , Iijima Shinji
Published: September 2005

In this study, we investigated the costimulatory activity of l‐selectin in primary mouse T cells. Proliferation induced by immobilized anti‐CD3 antibody was enhanced by immobilized anti‐l‐selectin antibody. In contrast to the anti‐CD28 antibody, anti‐l‐selectin antibody did not enhance interleukin‐2 (IL‐2) expression. One of the cyclin‐dependent kinase (cdk) inhibitors, p27, was reduced by costimulation with anti‐l‐selectin antibody, as with anti‐CD28 antibody, suggesting that the enhancement of T‐cell proliferation is the result of a reduced p27 level. Since anti‐l‐selectin antibody enhanced the activation of extracellular signal‐regulated protein kinase (ERK) induced by anti‐CD3 antibody, ERK plays an important role in signal integration during costimulation. These results suggest that the mechanism of T‐cell costimulation is at least partially different between CD28 and l‐selectin, although the two mechanisms share a common downstream event, a reduction of p27 level, as a critical biochemical event in the cell cycle progression of T cells.
Altered cytokine expression in mesenteric lymph nodes in a rat strain (Matsumoto Eosinophilic Shinshu) that spontaneously develops hypereosinophilia
Authors: Muto Shin‐ichi , Monnai Makoto , Okuhara Yuji , Murakami Makoto , Kuroda Junji , Ono Tamao , Matsumoto Kiyoshi
Published: September 2005

The Matsumoto Eosinophilic Shinshu (MES) rat is an inbred mutant strain that spontaneously develops systemic hypereosinophilia with eosinophilic inflammatory lesions similar to those associated with hypereosinophilic syndrome in humans and other mammals. To elucidate the pathogenic mechanisms that underlie these features of MES rats, we examined the pattern of cytokine gene expression in mesenteric lymph nodes (MLNs), the thymus, and peripheral blood mononuclear cells as well as the blood clinicopathology and MLN lymphocytic subsets of these animals. MES rats exhibited both leucocytosis, attributable in large part to hypereosinophilia and neutrophilia, and immunoglobulin M (IgM) and IgA gammaglobulinaemia, with increased titres of IgM autoantibodies to nuclear antigens. Reverse transcription and polymerase chain reaction analysis revealed that the amounts of interleukin (IL)‐5, IL‐4, eotaxin, and interferon‐γ mRNAs were increased in the MLN lymphocytes of MES rats compared with the corresponding values for Sprague‐Dawley rats. Intraperitoneal administration of a monoclonal antibody specific for IL‐5 resulted in an immediate suppression of hypereosinophilia and a delayed suppression of neutrophilia in MES rats. Flow cytometry revealed an increased percentage of CD3+ CD4– CD8– T lymphocytes in MLNs of MES rats. Our results suggest that the hypereosinophilia of MES rats results from an increased production of IL‐5, and that the eosinophilic inflammatory lesions of these animals, which are largely restricted to the gut, may be related both to cytokine overexpression in MLNs and to T helper 1 and 2 immunological responses.
CD27+ B cells in human lymphatic organs: re‐evaluating the splenic marginal zone
Authors: Steiniger Birte , Timphus Eva‐Maria , Jacob Ralf , Barth Peter J.
Published: September 2005

The marginal zone of human spleens is regarded as an organ‐specific region harbouring sessile memory B cells. This opinion has arisen by extrapolating from results obtained in mice and rats. Detection of CD27+ B cells in situ now revealed similarities among the most superficial region of B‐cell follicles in human spleens, reactive lymph nodes, inflamed appendices, tonsils and terminal ilea. The follicular surface in these organs consists of small naïve immunoglobulin D (IgD)+ CD27– B cells predominating in an inner area and larger IgD+/– CD27+ B cells prevailing in a more superficial position. CD27+ B cells may, however, also occupy the entire follicular periphery around the germinal centre. Together with additional peculiarities this distribution indicates a fundamental microanatomical difference among the human and rodent splenic white pulp. We hypothesize that the follicular periphery represents a recirculation compartment both for naïve and memory/natural reactive B cells in all human secondary lymphatic organs. This assumption implies a difference in recirculation behaviour among human and rodent B memory cells.
The effects of selected aldehydes, ketones and carboxylic acids on off‐flavours in water
Authors: Andersson Thorbjörn , Forsgren Gunnar , Nielsen Tim
Published: September 2005

The effects of selected aldehydes, ketones and carboxylic acids on the development of off‐flavours in water were studied. Combinations of hexanal, octanal, 2‐octanone, 5‐nonanone, hexanoic acid and nonanoic acid were rated by the off‐flavour intensities they created in water at concentrations just at or below the threshold value of each analyte. Two different sensory panels evaluated the off‐flavours induced by different combinations of the analytes. The observations of the two panels agreed well. From these studies, it could be concluded that aldehydes play an important role in the development of off‐flavours intensities in water. There were synergistic effects between aldehydes and ketones, as well as between aldehydes and carboxylic acids. Small amounts of aldehydes and carboxylic acids – well below their respective threshold values – caused an increase in the off‐flavour intensity. No synergism between ketones and carboxylic acids could be observed.
The effect of hydration time and ethanol concentration on the rate of hydrolysis of extracted vanilla beans by commercial cellulase preparations
Authors: Ovando Sandy L. , Waliszewski Krzysztof N. , Pardio Violeta T.
Published: September 2005

The rate of producing reducing sugars from extracted vanilla beans by using cellulolytic enzymes was studied. The hydration of cellulose improved the efficiency of hydrolysis. The treatment using Crystalzyme PML‐MX at a concentration of 2.64 International Filter Paper Units (IFPU) g−1 of bean was the most successful and the enzyme stable for up to 5:100 (weight:volume) of ethanol. After 48 h of prehydration and 26 h of enzymatic hydrolysis with this enzyme preparation, 196.6 mg g−1 reducing sugars containing 15.9 mg g−1 glucose were liberated. Less active enzyme products, Zymafilt L‐300 and Novozym, had greater cellulolytic activity when 10 or 15:100 (weight:volume) of ethanol were added respectively. Because of their stability with ethanol, the enzyme products could be used in the pretreatment of botanical material that are rich in flavour compounds and in this manner improve the final extraction of valuable flavours.
An evaluation of methyl 2‐oxocyclopentanecarboxylate as an iron(III) trap: food perspectives
Authors: Blanco Carlos , Rojas Antonio , Caballero Isabel , Alvarez Inmaculada , Armentia Alicia
Published: September 2005

The 1,3‐ketoesters have great potential in the food industry, as they are suitable for trapping flavours because of their chelating effects. The results obtained for tautomerization rate constants, as a function of temperature, have allowed us to establish a fourth order enthalpic analytical equation of temperature, suggesting an overall entropic control of tautomerization. Iron, which is present as a trace element in foods and drinks, is of critical importance for the normal early growth and development of infants. The nutritional status of iron may affect the metabolism of other nutrients. In fact, iron chelates have significant beneficial effects in increasing iron bioavailability in human diets. As a result the abilities of methyl 2‐oxocyclopentanecarboxylate to chelate iron(III) in aqueous solutions was investigated. Thermodynamic and kinetic parameters associated with the double‐pathway mechanism of monochelate complexation have been determined and the advantages of kinetically and thermodynamically controlled processes are discussed.
The characteristics of a microwave extraction process used for saikosaponins from Bupleurum falcatum root
Authors: Kwon Joong‐Ho , Choi Young‐Hui , Chung Hyung‐Wook , Lee Gee‐Dong
Published: September 2005

The characteristics of a microwave‐assisted process (MAPTM) for extraction of saikosaponins from Bupleurum falcatum root were monitored, predicted and optimized through response surface methodology. The maximum yield of total extract was 27.3% when using 102.1 W of microwave power, 54.3% ethanol concentration and extraction for 8.34 min. The extraction patterns for the individual saikosaponins a, c and d showed apparent differences in their response surfaces depending on the process conditions. The maximized extractable contents of saikosaponins a, c and d were predicted, respectively, to be 4.54, 0.45 and 7.31 mg g−1 under the respective conditions of 46.4, 40.7 and 117.2 W of microwave power, 34.7, 47.1 and 67.9% ethanol concentration, and extraction times of 8.0, 7.9 and 3.4 min. A comparison between the predicted and observed values for optimizing the extraction conditions resulted in insignificant differences.
Encouraging contributions in learning networks using incentive mechanisms
Authors: Hummel H.G.K. , Burgos D. , Tattersall C. , Brouns F. , Kurvers H. , Koper R.
Published: September 2005

Abstract
We investigate incentive mechanisms to increase active participation in Learning Networks (LNs). The LN under study is LN4LD, an LN for the exchange of information about the IMS Learning Design specification. We examine how to encourage learners in LN4LD to contribute their knowledge, and whether incentive mechanisms can increase the level of active participation. We describe an incentive mechanism based on constructivist principles and Social Exchange Theory, and experimentation using the mechanism designed to increase the level of active participation. The incentive mechanism allows individual learners to gain personal access to additional information through the accumulation of points earned by making contributions. Repeated measurements according to a simple interrupted time series with removal design show that the level of participation was indeed increased by the introduction of the reward system. It can therefore be considered worthwhile to use incentive mechanisms in LNs.
Learning objects: conditions for viability
Authors: Liber O.
Published: September 2005

Abstract This article elaborates the factors that have led to the emergence of the concept of learning objects as the predominant model for digital learning materials, examining the problems that they address. It suggests that while there do appear to be real benefits, for a learning object model to be successful there needs to be a thriving learning object economy. In turn, this demands a wide group of authors, drawn from the teaching community, and for these to participate there is an urgent requirement for tools that permit the easy creation and description of learning materials in learning objects format; but more importantly, support for sustainable communities of authors of digital learning materials.
Information commitments: evaluative standards and information searching strategies in web‐based learning environments
Authors: Wu Ying‐Tien , Tsai Chin‐Chung
Published: September 2005

Abstract
‘Information commitments’ include both a set of evaluative standards that Web users utilize to assess the accuracy and usefulness of information in Web‐based learning environments (implicit component), and the information searching strategies that Web users use on the Internet (explicit component). An ‘Information Commitment Survey’ (ICS), consisting of aforementioned components, was developed. The participants of this study were 610 university students, coming from four universities in Taiwan, and their information commitments were surveyed. Through a series of structural equation modelling (SEM) analyses with Linear Structure RELationships (LISREL), this study confirmed the reliability and validity of ICS. More importantly, the causal relationships between the two components of ICS were also examined. The findings showed that learners' evaluative standards on Web materials (implicit component) had significant effects on their information searching strategies in Web‐based learning environments (explicit component). For example, learners who utilized an advanced evaluative standard, such as using multiple sources to judge the accuracy of Web materials, were significantly more oriented toward using a sophisticated information searching strategy, such as carefully exploring and elaborating information in Web‐based learning environments. In other words, learners' evaluative standards for Web materials should be viewed as important predictors for their searching strategies in Web‐based learning environments.
Have gastrointestinal nematodes outwitted the immune system?
Authors: ELSE K. J.
Published: September 2005

Gastrointestinal (GI) nematodes are incredibly successful parasites. Choosing to live in an exposed extracellular niche, in confrontation with a potentially hostile environment, their persistent, chronic lifestyle is persuasive evidence in itself for their profound ability to modulate their hosts’ immune response. Modulation is essential to avoid their own destruction but also subtly balanced to avoid compromising host survival. This review describes the early circumstantial evidence that gave clues to the immunomodulatory capabilities of the GI nematodes, the roles that T regulatory cells and alternatively activated macrophages play in this immunomodulation and provides examples of the types of specific parasite‐derived factors that are known to modulate host immunity, potentiating parasite survival.
The Child Support Grant in South Africa: a social policy for poverty alleviation?
Authors: Triegaardt Jean D
Published: September 2005

The article analyses the Child Support Grant (CSG) in South Africa as a measure of poverty alleviation. Introduced in 1998 amid a great deal of controversy and fanfare, the CSG was a means‐tested cash benefit for poor children between the ages of 0 and 6 years, most of whom were located in the poorest of South Africa's nine provinces, i.e. the Eastern Cape, Kwazulu‐Natal and Limpopo (formerly known as the Northern Province). South Africa's unique history is discussed to show how the CSG became an important poverty alleviation measure. Debates surrounding the introduction of the CSG are discussed, not least its reliance on effective inter‐sectoral collaboration, research and the provision of developmental welfare programmes.
Educational attainments of former child welfare clients – a Swedish national cohort study
Authors: Vinnerljung Bo , Öman Maria , Gunnarson Thomas
Published: September 2005

We used national register data for nearly 800,000 Swedish‐born young people in eight national birth cohorts to examine educational attainments of former child welfare clients. A total of 31,355 former child welfare clients were compared with 744,425 majority population peers. Logistic regression models were used to estimate risks of having only a basic education at time of follow‐up, and of chances of having a post‐secondary education. Odds ratios for core results were recalculated into relative risks.

Compared with majority population peers with low educated mothers, children who experienced interventions before ado‐lescence, or had been in long‐term stable foster care, had a two‐ to threefold elevated relative risk of entering adult life with only a compulsory education. Youths who experienced intervention during adolescence had approximately a fourfold risk of having only basic education at the time of follow‐up. Majority population peers with low educated mothers were between two and six times more likely to have a post‐secondary degree when compared with former child welfare clients.
Parent–child relationships as perceived by Arab adolescents living in Israel
Authors: Azaiza Faisal
Published: September 2005

This article concerns how Arab adolescents living in Israel perceive their relationships with their parents by examining six domains of the adolescents’ worldviews: caring and trust, family support, control and supervision, general attitudes towards parents, and parent–child communication, both instru‐mental and intimate. The sample consists of 662 twelfth‐grade Arab adolescents from seven high schools. Findings show significant differences in various domains of Arab adole‐scents’ worldviews according to gender, form of residence and level of religiosity.
Extending social security in developing countries: a review of three main strategies
Authors: Overbye Einar
Published: September 2005

The article discusses strategies to extend social security cover‐age in developing and newly industrialised countries. The three major options are to extend social insurance coverage, to rely on mutuals or micro‐insurance or to bring in social assistance in one form or another. Social insurance usually covers small population segments. Insiders are seldom willing to extend coverage to poorer groups, as poorer groups are usually higher‐risk groups. Micro‐insurance and mutual societies work pri‐marily among people with similar risk profiles. Discretionary social assistance targets poorer groups, but is open to patronage and misuse. However, some social assistance designs are less open to misuse than others. Demogrants, i.e. benefits given to people in vulnerable social categories, are easy to administer and difficult to misuse. Whether or not a developing country provides such benefits can be considered an indicator of the willingness of the ruling elite to alleviate hardship among ‘unproductive’ population groups.
Allelic heterogeneity of the carbohydrate sulfotransferase‐6 gene in patients with macular corneal dystrophy
Authors: Sultana A , Sridhar M S , Klintworth G K , Balasubramanian D , Kannabiran C
Published: September 2005

Macular corneal dystrophy (MCD) is an autosomal recessive disorder characterized by grayish white opacities in the cornea. It is caused by mutations in the carbohydrate sulfotransferase‐6 (CHST6) gene, which codes for the enzyme corneal N‐acetylglucosamine‐6‐sulfotransferase. This enzyme catalyzes the sulfation of keratan sulfate, an important component of corneal proteoglycans. We screened 31 patients from 26 families with MCD for mutations in the coding region of the CHST6 gene. Twenty‐six different mutations were identified, of which 14 mutations are novel. The novel mutations are one nonsense mutation found in one patient (Trp2Ter), one frameshift (insertion plus deletion) mutation in two patients (His335fs), and 12 missense mutations (Leu3Met, Ser54Phe, Val56Arg, Ala73Thr, Ser98Leu, Cys165Trp, Ser167Phe, Phe178Cys, Leu193Pro, Pro204Arg, Arg272Ser, and Arg334Cys) in 11 patients. These data demonstrate a high degree of allelic heterogeneity of the CHST6 gene in patient populations with MCD from Southern India, where this disease may have a relatively higher prevalence than in outbred communities.
Genetic diagnosis of PLP gene duplications/deletions in patients with Pelizaeus–Merzbacher disease*
Authors: Gao Q , Thurston VC , Vance GH , Dlouhy SR , Hodes ME
Published: September 2005

PMD is an X‐linked recessive disorder due to a proteolipid protein (PLP) deficiency. Duplications of PLP gene were shown to be the principle cause of the disorder, accounting for an estimated 50‐70% of cases. To define a simple and reliable method for genetic diagnosis of PMD, a group of 42 patients with clinical manifestation of PMD was analyzed by means of real‐time quantitative PCR. Parallel fluorescence in situ hybridization (FISH) analysis was performed on the same group of patients. Real‐time PCR found seventeen samples had increased gene dosage, whereas FISH detected sixteen duplicated samples. Both methods identified a sample with PLP gene deletion. Our results indicate that real‐time PCR is a sensitive and reliable method for the detection of gene duplications/deletions. We further discussed the advantages and limitations of each method in clinical diagnosis of PMD.
Metabolic syndrome in bipolar disorder: findings from the Bipolar Disorder Center for Pennsylvanians
Authors: Fagiolini Andrea , Frank Ellen , Scott John A , Turkin Scott , Kupfer David J
Published: September 2005

Objective:  This study sought to evaluate the presence of the metabolic syndrome in a group of 171 patients with bipolar disorder who were consecutively recruited in the Bipolar Disorder Center for Pennsylvanians.

Methods:  Data were collected from participants entering the Bipolar Disorder Center for Pennsylvanians protocol between 2003 and 2004. The study focused on the presence of the metabolic syndrome, as defined by the National Cholesterol Education Program Expert Panel on Detection, Evaluation And Treatment of High Blood Cholesterol in Adults (NCEP ATP III).

Results:  Thirty percent of the sample met the NCEP ATP III criterion for the metabolic syndrome, 49% met the criterion for abdominal obesity, 41% met the criterion for hypertriglyceridemia, 48% met the criterion for hypertriglyceridemia or were on a cholesterol‐lowering medication, 23% met the criterion for low high‐density lipoprotein cholesterol, 39% met the criterion for hypertension and 8% met the criterion for high fasting glucose or antidiabetic medication use. Patients with the metabolic syndrome and patients endorsing the obesity criterion were more likely (p = 0.05 and p = 0.004, respectively) to report a lifetime history of suicide attempt/s.

Conclusions:  The prevalence of the metabolic syndrome in patients with bipolar disorder is alarmingly high, as it is for the general population. The prevalence of obesity is even higher than the already very high prevalence that has been estimated for the US general population. Our findings are a reason for concern, considering the difficulty in implementing prevention and treatment programs in the bipolar population. We strongly support the development and testing of interventions specifically designed for preventing and treating the metabolic syndrome and its components in patients with bipolar disorder.
Rapid mood switching and suicidality in familial bipolar disorder
Authors: MacKinnon Dean F , Potash James B , McMahon Francis J , Simpson Sylvia G , Raymond DePaulo J ,   the National Institutes of Mental Health Bipolar Disorder Genetics Initiative, Zandi Peter P
Published: September 2005

Objectives:  Rapidly alternating or mixed mood states in bipolar disorder are associated with a particularly high risk for suicidal behavior. Are individuals with these patterns of illness more likely to develop suicidal intentions, or are they less able to resist them? This analysis examines the specific contribution of rapid switching and other variables to the relative likelihood of having or acting on self‐reported suicidal thought and action, in a large group of individuals with bipolar disorder.

Methods:  The analysis included 1574 family members with bipolar disorder interviewed for a multi‐site bipolar disorder genetic linkage study. Two models were tested, using the same set of demographic and clinical data points as independent variables. One model tested the influence of rapid switching and other variables on self‐reported suicidal thought or action (i.e., suicidality), while the other tested the influences on suicidal action only among those who reported a history of suicidality.

Results:  Over 75% of subjects had contemplated suicide and 38% reported a history of suicidal behavior. A history of rapid switching was associated with higher likelihood of a history of suicidality, as was panic disorder. Familial suicidal behavior, as well as drug abuse, increased the likelihood of suicidal action among suicidal individuals, but did not increase the likelihood of becoming suicidal. Female sex, early age at onset, and several demographic factors were associated with both facets of suicidality.

Conclusions:  Factors associated with high acuity of distress, such as panic attacks and unstable moods, appear to enhance the risk of suicidality in general. Factors that affected the threshold for action without increasing suicidality overall can also be seen as markers of impulsive decision‐making. Of the two distinct kinds of suicidal risk, the latter – the likelihood of action given intent – appears to be the more familial.
Should bipolar disorder be viewed as manic disorder? Implications for bipolar depression
Authors: Schweitzer I , Maguire K , Ng CH
Published: September 2005

This paper proposes that the syndrome of mania rather than mood swings is the central distinguishing feature of bipolar disorder, which may be more appropriately viewed as manic disorder. The theoretical consequence of this change in perspective is to regard the depressive mood states as being a co‐morbid condition. This may lead to a more profound and broader understanding of the variety of states of depression that complicate manic disorder. The paper also reviews diagnostic issues relating to bipolar depression. A broader approach may extend therapeutic choices, and open innovative research avenues.
An interchangeable Mapleson A‐E breathing system is practical and cost effective
Authors: Robinson M. , Lighthall G. K.
Published: September 2005

Background:  In locations where oxygen and anesthesia gas supplies are limited, and where circle systems are not practical, means to reduce fresh gas flow during maintenance of inhalational anesthesia are of potential value. We investigated whether a common transport breathing apparatus could be modified to allow interchange between Mapleson D (Map‐D) and Mapleson A (Map A) configurations.

Methods:  A common Map‐D transport system was converted to a Map‐A system by switching positions of the exhaust valve and the elbow connector where fresh gas is delivered; these two breathing systems were compared in this study. The key question was whether rebreathing of CO2 could be eliminated at a lower fresh gas flow rate (FGF) with the Map‐A design. A structured protocol was followed.

Results:  A mean decrease in FGF of 2.8 l/min was seen with the Map‐A apparatus when compared with the Map‐D (P = 0.003). With no significant differences in physiologic or anesthetic variables, FGF/VE was significantly lower with the Mapleson A configuration than with the Mapleson D system design (1.1 vs. 1.8; P = 0.007). The extent to which FGF could be lowered when switching between Mapleson D and A systems correlated strongly with the patients' respiratory rate while under anesthesia (r = 0.45, P < 0.01).

Conclusions:  Cost and resource savings can be realized through the use of a breathing system modification that achieves appropriate ventilation at lower fresh gas flows.
Comparison of airway management with the intubating laryngeal mask, laryngeal tube and CobraPLA® by paramedical students in anaesthetized patients
Authors: Kurola J. , Pere P. , Niemi‐Murola L. , Silfvast T. , Kairaluoma P. , Rautoma P. , Castrén M.
Published: September 2005

Background:  Because of the importance of airway management in emergency care, alternative methods with shorter learning curves for inexperienced personnel have been looked for as a substitute for endotracheal intubation (ETI).

Methods:  We compared the success of insertion, oxygenation and ventilation of the intubating laryngeal mask (ILMA), laryngeal tube (LT) and CobraPLA® (COB) in anaesthetized patients when used by paramedical students. After informed consent, 96 patients were monitored and anaesthetized for general surgery without the use of a muscle relaxant. After the induction of anaesthesia, 32 paramedical students inserted the ILMA, LT or COB in a random order and ventilated the patient for a 60‐s period. The number of insertion attempts, the time needed for insertion, and oxygenation and ventilation parameters were recorded. The students gave a subjective evaluation of the airway devices after the test.

Results:  Twenty‐four of the 32 students (75%) successfully inserted ILMA at the first attempt, compared with 14 of 32 (44%) for LT and seven of 32 (22%) for COB (P < 0.001, ILMA vs. COB). One student failed to insert ILMA after all three attempts, compared with seven of 32 (21%) using LT and seven of 32 (21%) using COB (P = not significant). Oxygenation and ventilation parameters did not differ between the groups after successful insertion.

Conclusion:  Clinically inexperienced paramedical students can successfully use ILMA in anaesthetized patients. Further investigations are warranted to study whether ILMA or LT can replace ETI in emergency airway management when used by inexperienced medical or paramedical staff.