Cartilage repair strategies in the knee according to Dutch Orthopedic Surgeons: a survey study.

BACKGROUND: This study surveyed Dutch orthopedic surgeons on the management of cartilage defects in the knee and the adherence to the recently updated Dutch knee cartilage repair consensus statement (DCS). METHODS: A web-based survey was sent to 192 Dutch knee specialists. RESULTS: The response rate was 60%. Microfracture, debridement and osteochondral autografts are performed by the majority, 93%, 70% and 27% of respondents, respectively. Complex techniques are used by < 7%. Microfracture is mainly considered in defects 1-2 cm2 (by > 80%) but also in 2-3 cm2 (by > 40%). Concomitant procedures, e.g., malalignment corrections, are performed by 89%. Twenty-one percent of surgeons treat patients aged 40-60 years. Microfracture, debridement and autologous chondrocyte implantation are not considered to be highly affected by age > 40 years by any of the respondents (0-3%). Moreover, for the middle-aged there is a large spread in treatments considered. In case of loose bodies, the majority (84%) only performs refixation in the presence of attached bone. CONCLUSION: Small cartilage defects in ideal patients may be well treated by general orthopedic surgeons. The matter becomes complicated in older patients, or in case of larger defects or malalignment. The current study reveals some knowledge gaps for these more complex patients. Referral to tertiary centers might be indicated, as is stated by the DCS, and this centralization should enhance knee joint preservation. Since the data from present study are subjective, registration of all separate cartilage repair cases should fuel objective analysis of clinical practice and adherence to the DCS in the future.

Changes in facial signs due to age and their respective weights on the perception of age, on a tired-look or a healthy glow among differently aged Chinese men.

OBJECTIVE: To determine the respective weights of certain facial signs on the assessment of perceived age, tired-look and healthy glow on Chinese men of different ages. MATERIAL AND METHODS: Photographs were taken of the faces of 420 Chinese men of different ages, under standardized conditions. These photographs allowed to focus and define 15 facial signs, which were then graded by 15 experts and dermatologists, using standardized scales provided by a reference Skin Aging Atlas. The facial signs were dispatched into 5 clusters, namely wrinkles/texture, ptosis/sagging, pigmentation disorders, vascular disorders and cheek skin pores. A naïve panel, composed of 80 Chinese women, of similar age range were asked, when viewing full-face photographs, to: (i) attribute on a 0-10 scale their perception of both the tired-look and healthy glow aspects and (ii) estimate the age of the subject. RESULTS: With the exception of vascular disorders, the severity of all 4 clusters increased with age, although at different rates. The ptosis/sagging or pigmentation disorders showed a rather regular progression. Although perceived ages and real ages were found to be closely correlated, the vast majority of subjects were judged older by 2-10 years. The changes in facial signs (and their related clusters) were significantly correlated with perceived age, with the exceptions of skin spot density and cheek skin pores. Although the aspects of tired-look and healthy glow were logically found to be anti-correlated, tired-look was more statistically associated with perceived age for the five clusters. Signs of eye contour appear to be closely correlated with the perception of a tired-look. CONCLUSION: Within facial clinical clusters, wrinkles/texture and ptosis/sagging are major factors in the assessment of perceived age in Chinese men. Tired-look appears to be strongly associated with perceived age.

OBJECTIF: De déterminer, pour des hommes chinois d'âges différents, les poids respectifs de certains signes faciaux entrant dans l'estimation de la perception des visages pour l'âge, l'air fatigué ou l'éclat. MATÉRIEL ET MÉTHODES: Les visages de 420 hommes chinois d'âges différents ont été photographiés dans des conditions standardisées. Ces clichés ont permis à 15 experts et dermatologistes d'évaluer 15 signes cliniques selon des échelles éditées dans les références Atlas Cliniques du Vieillissement. Ces signes faciaux sont regroupés dans 5 groupes (rides/texture, ptose/relâchement, désordres pigmentaires, désordres vasculaires, pores de la joue). Un panel de 80 consommatrices chinoises, d'un âge comparable, a été recruté pour donner leurs perceptions sur chaque visage complet photographié: d'abord en attribuant sur une échelle de 0 à 10 un score pour leurs perceptions de l'air fatigué et de l'aspect éclatant de santé, puis en estimant l'âge apparent du volontaire. RÉSULTATS: A l'exception des Désordres vasculaires, la sévérité des 4 groupes cliniques s'accroit avec l'âge selon des cinétiques différentes, parmi lesquelles la ptose/relâchement ou les désordres pigmentaires montrent la progression la plus constante et linéaire. Malgré une très importante et significative corrélation entre âge apparent et âge réel, une majorité des volontaires ont été jugés plus vieux que leurs âges réels, entre 2 et 10 ans. Les variations des signes faciaux (ou des groupes cliniques associés) ont été montrés significativement corrélées à l'âge apparent, à l'exception de la densité des taches pigmentaires et des pores de la joue. Bien que l'air fatigué et l'éclat sont logiquement observés comme anti-corrélés, c'est l'air fatigué qui se trouve le plus relié à l'âge apparent sur les 5 groupes cliniques. Les signes du contour des yeux apparaissent comme les plus corrélés à la perception de l'air fatigué. CONCLUSION: Parmi les groupes cliniques, les rides/texture et la ptose/relâchement sont les facteurs majeurs dans l'attribution d'un âge perçu pour les hommes chinois. L'air fatigué apparaît comme très fortement relié à l'âge apparent.

A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources.

Radiodonts, a clade of Cambro-Devonian stem group euarthropods, have classically been regarded as nektonic apex predators. However, many aspects of radiodont morphology and ecology have remained unclear because of the typically fragmentary nature of fossil material. Here, we describe a new hurdiid radiodont based on abundant and exceptionally well-preserved fossils from the Burgess Shale (Marble Canyon area, British Columbia, Canada). Cambroraster falcatus gen. et sp. nov. is characterized by an extra-large horseshoe-shaped head carapace, bearing conspicuous posterolateral spinous processes, and partially covering a short trunk with eight pairs of lateral flaps. Each of the pair of frontal appendages possess five mesially curving rake-like endites equipped with a series of anteriorly directed hooked spines, altogether surrounding the oral cone. This feeding apparatus suggests a micro to macrophagous sediment-sifting feeding ecology. Cambroraster illuminates the evolution of Hurdiidae and evinces the exploitation of the diversifying infauna by these large and specialized nektobenthic carnivores in the aftermath of the Cambrian explosion.

Burgess Shale fossils shed light on the agnostid problem.

Agnostids (agnostinids and eodiscinids) are a widespread and biostratigraphically important group of Cambro-Ordovician euarthropods whose evolutionary affinities have been highly controversial. Their dumbbell-shaped calcified tergum was traditionally suggested to unite them with trilobites, but agnostinids have alternatively been interpreted as stem-crustaceans, based on Orsten larval material from the Cambrian of Sweden. We describe exceptionally preserved soft tissues from mature individuals of the agnostinids Peronopsis and Ptychagnostus from the middle Cambrian (Wuliuan Stage) Burgess Shale (Walcott Quarry and Marble Canyon, British Columbia, Canada), facilitating the testing of alternative hypotheses. The digestive tract includes conspicuous ramifying cephalic diverticulae. The cephalon carries one pair of elongate spinous antennules projecting to the front, two pairs of appendages with distally setose, oar-like exopods, and three pairs of presumably biramous appendages with endopods sporting club-shaped exites. The trunk bears five appendage pairs, at least the first two of which are similar to the posteriormost cephalic pairs. The combined evidence supports a nektobenthic and detritivorous lifestyle for agnostinids. A head with six appendiferous segments contrasts strikingly with the four known in trilobites and five typical of mandibulates. Agnostinids are retrieved as the sister group to polymeroid trilobites in our phylogeny, implying that crustacean-like morphologies evolved homoplastically. This result highlights the variability in segmental composition of the artiopodan head. Finally, our study emphasizes the continued role of Burgess Shale-type fossils in resolving the affinities of problematic biomineralizing taxa.

[Clinical audit on drug prescriptions for elderly patients hospitalized in a unit of psychiatry]. / Audit clinique ciblé sur la prise en charge médicamenteuse chez le sujet âgé hospitalisé en psychiatrie.

BACKGROUND: The elderly are particularly vulnerable to the iatrogenic effects of drugs that are a major public health problem. In a geriatric care unit of a psychiatric hospital, the pharmacist, in close cooperation with the various health professionals, takes part in the optimization of drug therapy of these patients during cross-professional consultation meetings. From 2009 to 2011, an evaluation of professional practices was run through a targeted clinical audit on the theme of "prescription drugs at the age of 75 and over". The main objective of this study is to measure the differences between the practices and the guidelines for prescription drugs concerning the elderly, and then to analyze and amend these differences. The secondary objective is to gather data on the prescription drugs for the elderly in the particular context of a psychiatric unit. METHODS: The evaluation was performed using two standards: the evaluation chart of prescriptions of the Professional College of French Geriatrics (CPGF) and the French National Authority for Health and the list of Laroche et al. In the first round, after analyzing the prescriptions of 105 patients, the gap between practice and accepted standards led to the definition of three areas of improvement on the associations of neuroleptics, on the use of anticholinergic drugs and on the prescription of benzodiazepines, the latter being subject of another communication. After reassessment, the prescriptions of 101 patients were thereafter analyzed in relation to the identified areas of improvement. RESULTS: Patient samples of both phases were statistically homogeneous. Between the two evaluations, the percentage of prescriptions with at least two neuroleptics remained stable, the decline was not significant (18.1% to 13.9%, P≥0.05). However, it was observed that the second suggested a "conditional" decline with dosages less than or equal to those recommended for the elderly dosages. The proportion of patients who did not take anticholinergic drugs increased from 30% to 60% (P≤0.01). In parallel to the improvement of these criteria, it was noted that the average number of psychotropic drugs prescribed was significantly reduced (from 3.3 to 2.79 psychotropic/patients, P=0.078). DISCUSSION: The involvement of a pharmacist in cross-professional meetings of a care unit of psychiatry for the elderly has contributed in setting up a clinical audit focused on the drug management of these patients. This work enabled measurement of the progress made in the use of anticholinergic drugs, following the guidelines. In the mean time, it has been highlighted that the standards used are difficult to comply with regarding some criteria. For instance, the use of neuroleptics in the case of elderly patients hospitalized in the unit of psychiatry and not in the unit of geriatrics requires specific adjustments. Indeed, there are patients whose disorders have led to psychiatric hospitalization, which may require a combination of two neuroleptics. This paved the way for us to develop, within a working group representative of all professionals involved, a list fitting our medical practice and integrated into a guidebook adapted to the drug therapy management of elderly patients in psychiatry. The approach being successful, this targeted clinical audit will be extended to patients aged 75 years and over, hospitalized in other care units of the hospital.

Block Magnetic Excitations in the Orbitally Selective Mott Insulator BaFe_{2}Se_{3}.

Iron pnictides and selenides display a variety of unusual magnetic phases originating from the interplay between electronic, orbital, and lattice degrees of freedom. Using powder inelastic neutron scattering on the two-leg ladder BaFe_{2}Se_{3}, we fully characterize the static and dynamic spin correlations associated with the Fe_{4} block state, an exotic magnetic ground state observed in this low-dimensional magnet and in Rb_{0.89}Fe_{1.58}Se_{2}. All the magnetic excitations of the Fe_{4} block state predicted by an effective Heisenberg model with localized spins are observed below 300 meV and quantitatively reproduced. However, the data only account for 16(3)µ_{B}^{2} per Fe^{2+}, approximatively 2/3 of the total spectral weight expected for localized S=2 moments. Our results highlight how orbital degrees of freedom in iron-based magnets can conspire to stabilize an exotic magnetic state.

Norms of the Attitudes Toward Intellectual Disability Questionnaire.

BACKGROUND: The Attitudes Toward Intellectual Disability Questionnaire (ATTID) has demonstrated good psychometric qualities for measuring the attitudes of different groups of adults in the general population toward intellectual disability (ID). A significant advantage of the ATTID is that it addresses the concept of attitudes using a three-dimensional model (affective, cognitive and behavioural). To our knowledge, there are no normative data published regarding attitudes toward ID on general population-based samples. METHODS: The sample of 1605 men and women was stratified to be representative of the general adult population of Quebec. The ATTID was administered by phone interview through an independent survey firm. RESULTS: Normative data are presented as percentile scores associated with the raw score of the ATTID by gender and age categories. Analysis of the variance yielded significant differences in attitude by gender and age. The directions and the strength of these associations vary according to each of the five factors used to define attitudes. CONCLUSION: These norms will provide an essential tool to compare different groups and assess the effectiveness of various public campaigns to encourage more positive attitudes towards persons with ID. These norms would also allow international comparisons.

Public attitudes towards intellectual disability: a multidimensional perspective.

BACKGROUND: Public attitudes towards persons with intellectual disabilities (IDs) have a significant effect on potential community integration. A better understanding of these can help target service provision and public awareness programmes. OBJECTIVE: The objective of the present study is threefold: (1) describe public attitudes towards persons with ID along affective, cognitive and behavioural dimensions; (2) compare and contrast attitudes according to sex, age, education and income, as well as frequency and quality of contacts with persons with ID; and (3) ascertain whether the level of functioning has an effect on attitudes. METHODS: The Attitudes Toward Intellectual Disability Questionnaire (ATTID) was administered by phone to 1605 randomly selected adult men and women, stratified by region in the province of Québec, Canada. The ATTID uses a multidimensional perspective of attitudes that reflect affective, cognitive and behavioural dimensions. RESULTS: The results showed that public attitudes were generally positive regarding all three attitudinal dimensions. Public attitudes towards persons with ID are presented in terms of the five factors measured through the ATTID: (1) discomfort; (2) sensibility or tenderness; (3) knowledge of causes; (4) knowledge of capacity and rights; and (5) interaction. Attitude factor scores vary as a function of participant characteristics (sex, age, education and income) and the degree of knowledge about ID, the number of persons with ID known to the participants, as well as the frequency and quality of their contacts with these persons. Men had greater negative attitudes than women as regards the discomfort factor, while women had more negative attitudes regarding the knowledge of capacity and rights factor. More positive attitudes were revealed among younger and more educated participants. Attitudes were generally not associated with income. Public attitudes tended to be more negative towards people with lower functioning ID. CONCLUSION: These results yield useful information to target public awareness and education.

Validation of the attitudes toward intellectual disability: ATTID questionnaire.

BACKGROUND: Individuals with an intellectual disability (ID) continue to experience major obstacles towards social, educational and vocational integration. Negative attitudes toward persons with ID has remained relevant over time and has led to discrimination and stigma. OBJECTIVE: The present study describes the development of a new questionnaire for tapping into the general population's attitudes toward individuals with ID and addresses its psychometric properties. METHODS: Adopting a multidimensional perspective, the Attitudes Toward Intellectual Disability Questionnaire (ATTID) was developed from a series of previously validated instruments and principles from the Montreal Declaration on Intellectual Disability (2004). The ATTID was administered by phone to 1605 randomly selected adult men and women, stratified by region in the Province of Quebec, Canada. RESULTS: The ATTID yielded a five-factor structure overlapping the tri-partite model of attitudes. The cognitive component was represented by two factors: knowledge of capacity and rights and knowledge of causes of ID. The affective component tapped into two factors: discomfort and sensitivity/compassion. Finally, the behavioural component emerged as a single factor. The ATTID had good internal consistency with Cronbach's alpha coefficients ranging from 0.59 to 0.89 for the five factors and of 0.92 for the overall questionnaire. Test-retest reliability yielded correlations from 0.62 to 0.83 for the five factors. CONCLUSION: The ATTID can be used to measure attitudes among different populations and allows comparisons over time within the same population as a function of various intervention strategies for de-stigmatising ID.

Performance characteristics of two automated solid-phase red cell adherence systems for pretransfusion antibody screening: a cautionary tale.

Out institution has implemented two instruments, the Galileo and the Echo, that use different solid-phase red cell adherence assays for antibody screening in pretransfusion compatibility testing.During the initial implementation of these two instruments, we noticed very different problems: falsely positive results on the Galileo, and falsely negative results and lack of reproducibility on the Echo. Comparison of falsely positive antibody screen results from approximately equivalent numbers of samples run on the Galileo and samples tested by standard manual tube technique using low-ionic-strength saline enhancement showed a false-positive rate of 1.4 percent on the Galileo (defined as a positive screen with a negative panel). Testing using the Echo identified four cases of falsely negative antibody screens, (defined as a negative screen on a patient sample subsequently shown to be positive by the same method). In addition, we note a lack of reproducibility on the Echo, which emphasizes the importance of replicate testing during validation of automated antibody screening platforms.

A multi-level study of the determinants of mental health service utilization.

BACKGROUND: Until now, research has focused on neighbourhood variations in mental health services and their relationships with local attributes, such as healthcare supply and socio-economic deprivation, without controlling for individual characteristics (age, sex, income, or education, for instance). Hence, this study is a major attempt to clarify the role played by individual and local attributes in the utilization of mental health services. The aim of this study was to disentangle individual and neighbourhood effects on mental health service use. METHODS: In this cross-sectional study, individual-level data on 423 participants with a frequent mental health disorder was recruited from the general population and linked to neighbourhood-level data at the census tract level from the 2006 Canadian Census. Neighbourhood variables included socio-economic deprivation, mean income, residential stability and the proportion of recent immigrants. Individual characteristics included gender, age, marital status, self-rated mental health and the number of diagnoses. Multi-level logistic regression was used to assess the effects of individual and neighbourhood characteristics simultaneously on mental health service use. RESULTS: The intraclass correlation coefficient indicated that 12.26% of the variance of mental health service utilization is at the neighbourhood level. Final analysis showed that at the individual level, being female, married, or self-rating mental health less than excellent increased healthcare use. At the neighbourhood level, deprived socio-economic neighbourhood decreased health service use (OR=0.71, P<0.05), while residential stability increased use (OR=1.24, P<0.05). CONCLUSIONS: Individual and neighbourhood characteristics determine mental health service utilization. Taking both into consideration allows better targeting of health service policy and planning and enables more accurate needs-based resource allocation. However, future research should continue to investigate the pathway through which neighbourhood affects health service utilization.

To what extent do social support and mastery mediate the association between childhood maltreatment and depression? A sequential causal mediation analysis.

AIMS: This study aimed to examine the independent roles of various childhood maltreatment (CM) subtypes in the development of depression; quantify the joint mediation effect of social support and mastery in the association between subtypes of CM and depression and examine the additional contribution of mastery beyond the effect that is operating through social support to this relationship. METHODS: Data analysed were from the Zone d'Épidémiologie Psychiatrique du Sud-Ouest de Montréal, an ongoing longitudinal population-based study. In total, 1351 participants with complete information on the studied variables were included. The propensity score matching and inverse-probability weighted regression adjustment estimation methods were used to minimise the potential confounding in the relationship between CM and major depression. We then used inverse odds ratio-weighted estimation to estimate the direct effects of maltreatment and indirect effects of social support and mastery. RESULTS: We found that exposures to all maltreatment subtypes increased the risk of subsequent depression. The joint mediating effect of social support and mastery explained 37.63-46.97% of the association between different maltreatment subtypes and depression. The contribution of these two mediators differed by maltreatment subtypes, with social support being the major contributor to the mediating effect. CONCLUSIONS: The findings of the study not only provide scientific evidence on the importance of psychosocial attributes in the development of major depression but also suggest that prevention and invention strategies should focus on these psychosocial attributes to effectively break the vicious cycle of CM on major depression.

Specific and cumulative lifetime stressors in the aetiology of major depression: A longitudinal community-based population study.

AIMS: Early-life stressful circumstances (i.e. childhood maltreatment) coupled with stressful events later in life increase the likelihood of subsequent depression. However, very few studies have been conducted to examine the specific and cumulative effects of these stressors in the development of depression. There is also a paucity of research that simultaneously considers the role of biological factors combined with psychosocial stressors in the aetiology of depression. Guided by the biopsychosocial model proposed by Engel, the present study aims to examine to what extent the experience of stressors across the lifespan is associated with depression while taking into account the role of genetic predispositions. METHODS: Data analysed were from the Social and Psychiatric Epidemiology Catchment Area of the Southwest of Montreal (ZEPSOM), a large-scale, longitudinal community-based cohort study. A total of 1351 participants with complete information on the lifetime diagnoses of depression over a 10-year follow-up period were included in the study. Stressful events across the lifespan were operationalised as specific, cumulative and latent profiles of stressful experiences. Latent profile analysis (LPA) was used to explore the clustering of studied stressors including childhood maltreatment, poor parent-child relationship, and stressful life events. A polygenetic risk score was calculated for each participant to provide information on genetic liability. Multivariate logistic regression was used to examine the association between specific, cumulative and latent profiles of stressors and subsequent depression. RESULTS: We found that different subtypes of childhood maltreatment, child-parent bonding and stressful life events predicted subsequent depression. Furthermore, a significant association between combined effects of cumulative stressful experiences and depression was found [odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.12-1.28]. Three latent profiles of lifetime stressors were identified in the present study and named as 'low-level of stress' (75.1%), 'moderate-level of stress' (6.8%) and 'high-level of stress' (18.1%). Individuals with a 'high-level of stress' had a substantially higher risk of depression (OR = 1.80, 95% CI: 1.08-3.00) than the other two profiles after adjusting for genetic predispositions, socio-demographic characteristics, and health-related factors. CONCLUSIONS: While controlling for genetic predispositions, the present study provides robust evidence to support the independent and cumulative as well as compositional effects of early- and later-on lifetime psychosocial stressors in the subsequent development of depression. Consequently, mental illness prevention and mental health promotion should target the occurrence of stressful events as well as build resilience in people so they can better cope with stress when it inevitably occurs.

Comparison of conventional and alternative arthroscopic approaches to the palmar/plantar pouch of the equine distal interphalangeal joint.

REASONS FOR PERFORMING THE STUDY: The conventional arthroscopic approach to the palmar/plantar aspect of the distal interphalangeal joint (DIPJ) may result in the inadvertent penetration of the digital flexor tendon sheath (DFTS) and the navicular bursa (NB). This iatrogenic communication would be undesirable subsequent to arthroscopic lavage of a septic DIPJ. HYPOTHESIS: A lateral/medial approach to the palmar/plantar aspect of the DIPJ will result in a significantly lower rate of inadvertent penetration of the DFTS and NB, whilst still providing adequate intra-articular evaluation. METHODS: The conventional palmar/plantar approach or a novel lateral/medial approach to the DIPJ was performed on cadaver fore- and hindlimbs (30 limbs/approach). Subsequently, India ink was injected into the dorsal pouch of the DIPJ, and the DFTS (n = 60) and NB (n = 20) were examined for the presence/absence of ink. In addition, observations of the number of attempts made to access the joint, evidence of iatrogenic intra-articular trauma and occurrence of incomplete visualisation of the palmar/plantar pouch were recorded. RESULTS: With the conventional approach, DFTS penetration was noted in 18/30 (60%) of the limbs, compared to 1/30 (3.3%) with the lateral/medial approach (P≤0.001). NB penetration was seen in 5/10 limbs with the palmar/plantar approach compared to 0/10 with the lateral/medial approach (P = 0.01). No significant differences were found between the approaches in the number of attempts made to access the joint, the incidence of iatrogenic intra-articular trauma, or the occurrence of incomplete visibility of the palmar/plantar pouch. CONCLUSIONS: The novel lateral/medial approach to the DIPJ significantly decreases the risk of inadvertent penetration of the DFTS and NB. POTENTIAL RELEVANCE: The novel lateral/medial approach to the DIPJ is an effective technique to gain access to the palmar/plantar pouches, and is particularly advantageous for arthroscopic lavage of a septic DIPJ.

A giant nektobenthic radiodont from the Burgess Shale and the significance of hurdiid carapace diversity.

Radiodonts, stem-group euarthropods that evolved during the Cambrian explosion, were among the largest and most diversified lower palaeozoic predators. These animals were widespread geographically, occupying a variety of ecological niches, from benthic foragers to nektonic suspension feeders and apex predators. Here, we describe the largest Cambrian hurdiid radiodont known so far, Titanokorys gainesi, gen. et sp. nov., from the Burgess Shale (Marble Canyon, Kootenay National Park, British Columbia). Estimated to reach half a metre in length, this new species bears a very large ovoid-shaped central carapace with distinct short posterolateral processes and an anterior spine. Geometric morphometric analyses highlight the high diversity of carapace shapes in hurdiids and show that Titanokorys bridges a morphological gap between forms with long and short carapaces. Carapace shape, however, is prone to homoplasy and shows no consistent relationship with trophic ecology, as demonstrated by new data, including a reappraisal of the poorly known Pahvantia. Despite distinct carapaces, Titanokorys shares similar rake-like appendages for sediment-sifting with Cambroraster, a smaller but much more abundant sympatric hurdiid from the Burgess Shale. The co-occurrence of these two species on the same bedding planes highlights potential competition for benthic resources and the high diversity of large predators sustained by Cambrian communities.

Off-axis electron holography of Néel-type skyrmions in multilayers of heavy metals and ferromagnets.

Magnetic skyrmions are complex swirling spin structures that are of interest for applications in energy-efficient memories and logic technologies. Multilayers of heavy metals and ferromagnets have been shown to host magnetic skyrmions at room temperature. Lorentz transmission electron microscopy is often used to study magnetic domain structures in multilayer samples using mainly Fresnel defocus imaging. Here, off-axis electron holography is used to obtain in-focus electron optical phase images of Néel-type domains and skyrmions in an Ir/Fe/Co/Pt multilayer sample. The preparation of the sample, reconstruction of the holograms and influence of sample tilt angle on the signal-to-noise ratio in the phase images are discussed. A good agreement is found between images of individual skyrmions that are stabilized using an external magnetic field and simulated images based on theoretical models of Néel-type skyrmions.

Decrease in serum level of matrix metalloproteinases is predictive of the disease-modifying effect of osteoarthritis drugs assessed by quantitative MRI in patients with knee osteoarthritis.

OBJECTIVES: To explore the impact of disease-modifying osteoarthritis drug (DMOAD) treatment on biomarker levels and their correlation with cartilage volume loss and disease symptoms in a 2-year phase III clinical trial in patients with knee OA. METHODS: 161 patients with knee OA (according-to-protocol population) were selected from a 2-year DMOAD trial studying the effect of licofelone (200 mg twice daily) versus naproxen (500 mg twice daily). Clinical evaluation of patients was carried out using the Western Ontario and McMaster Universities (WOMAC) questionnaire. Biomarker measurements of matrix metalloproteinase (MMP)-1, MMP-3, interleukin (IL)-6, C reactive protein (CRP), cartilage oligomeric matrix protein (COMP) and type I collagen C-terminal telopeptide (CTX-I) in serum, type II collagen C-terminal telopeptide (CTX-II) in urine, and knee MRI were performed at baseline and 2 years. RESULTS: Over time an increase occurred in all biomarker levels with the exception of IL-6, CRP and CTX-II which decreased. The increase in MMP-1 and MMP-3 was significantly less (p = 0.05; p < 0.01, respectively) in the licofelone group. The baseline MMP-1 level was significantly but inversely predictive of cartilage volume loss for the medial compartment in both univariate (p = 0.04) and multivariate (p ≤ 0.04) regression analyses, and COMP, a predictor for the lateral compartment, in both univariate and multivariate models (p < 0.01). Baseline levels of IL-6 and CRP also showed a significant relationship with volume loss for the medial compartment (univariate analysis, p = 0.04 and p = 0.01, respectively; multivariate analysis, p = 0.03, p = 0.01). A significant association (univariate) was observed between the change in the levels of MMP-1 (p = 0.03) and MMP-3 (p = 0.02) and cartilage volume loss (lateral compartment) over 2 years. Baseline levels of CTX-I correlated (p = 0.02) with an increase in the size of the bone marrow lesion in the medial compartment. The baseline CRP levels correlated with worsening of symptoms: WOMAC total index (p < 0.01), pain (p < 0.01) and function (p < 0.01). CONCLUSION: Higher baseline values of IL-6, CRP and COMP are predictive of greater risk of cartilage loss in OA. However, over time a reduction in MMP-1 and MMP-3 levels correlated best with reduction in cartilage volume loss and the effect of drug treatment. Baseline CRP was found to be a good predictor of the symptomatic response to treatment.

A descriptive study of the prevalence of psychological distress and mental disorders in the Canadian population: comparison between low-income and non-low-income populations.

OBJECTIVE: This descriptive study compares rates of high psychological distress and mental disorders between low-income and non-low-income populations in Canada. METHODS: Data were collected through the Canadian Community Health Survey - Mental Health and Well-being (CCHS 1.2), which surveyed 36 984 Canadians aged 15 or over; 17.9% (n = 6620) was classified within the low-income population using the Low Income Measure. The K-10 was used to measure psychological distress and the CIDI for assessing mental disorders. RESULTS: One out of 5 Canadians reported high psychological distress, and 1 out of 10 reported at least one of the five mental disorders surveyed or substance abuse. Women, single, separated or divorced respondents, non-immigrants and Aboriginal Canadians were more likely to report suffering from psychological distress or from mental disorders and substance abuse. Rates of reported psychological distress and of mental disorders and substance abuse were much higher in low-income populations, and these differences were statistically consistent in most of the sociodemographic strata. CONCLUSION: This study helps determine the vulnerable groups in mental health for which prevention and promotion programs could be designed.

Interaction of microtubule proteins with phospholipid vesicles.

We have examined the interaction of unilamellar dimyristoyl phosphatidylcholine liposomes with the high-speed supernate of brain homogenate and with tubulin purified through one or two cycles of microtubule assembly-disassembly. Tubulin and certian high molecular weight proteins are selectively adsorbed from these mixtures onto liposomes. The composition of adsorbed proteins is similar to that obtained during corresponding cycles of microtubule assembly, suggesting the equivalency of these processes. Adsorption induces stacking and/or fusion of liposomes into multilamellar structures indicating strong protein-lipid interaction. In addition, liposome-adsorbed tubulin forms extensive intermolecular disulfide bridges that are inert to reducing agents in the aqueous medium. The observations form a basis for further study of the distribution, function, and properties of membrane-bound tubulin.