High-risk pooling for mitigating risk selection incentives in health insurance markets with sophisticated risk equalization: an application based on health survey information.

BACKGROUND: Despite sophisticated risk equalization, insurers in regulated health insurance markets still face incentives to attract healthy people and avoid the chronically ill because of predictable differences in profitability between these groups. The traditional approach to mitigate such incentives for risk selection is to improve the risk-equalization model by adding or refining risk adjusters. However, not all potential risk adjusters are appropriate. One example are risk adjusters based on health survey information. Despite its predictiveness of future healthcare spending, such information is generally considered inappropriate for risk equalization, due to feasibility challenges and a potential lack of representativeness. METHODS: We study the effects of high-risk pooling (HRP) as a strategy for mitigating risk selection incentives in the presence of sophisticated- though imperfect- risk equalization. We simulate a HRP modality in which insurers can ex-ante assign predictably unprofitable individuals to a 'high risk pool' using information from a health survey. We evaluate the effect of five alternative pool sizes based on predicted residual spending post risk equalization on insurers' incentives for risk selection and cost control, and compare this to the situation without HRP. RESULTS: The results show that HRP based on health survey information can substantially reduce risk selection incentives. For example, eliminating the undercompensation for the top-1% with the highest predicted residual spending reduces selection incentives against the total group with a chronic disease (60% of the population) by approximately 25%. Overall, the selection incentives gradually decrease with a larger pool size. The largest marginal reduction is found moving from no high-risk pool to HRP for the top 1% individuals with the highest predicted residual spending. CONCLUSION: Our main conclusion is that HRP has the potential to considerably reduce remaining risk selection incentives at the expense of a relatively small reduction of incentives for cost control. The extent to which this can be achieved, however, depends on the design of the high-risk pool.

Cartesian constraints in QM/MM optimizations.

With the rise of quantum mechanical/molecular mechanical (QM/MM) methods, the interest in the calculation of molecular assemblies has increased considerably. The structures and dynamics of such assemblies are usually governed to a large extend by intermolecular interactions. As a result, the corresponding potential energy surfaces are topological rich and possess many shallow minima. Therefore, local structure optimizations of QM/MM molecular assemblies can be challenging, in particular if optimization constraints are imposed. To overcome this problem, structure optimization in normal coordinate space is advocated. To do so, the external degrees of freedom of a molecule are separated from the internal ones by a projector matrix in the space of the Cartesian coordinates. Here we extend this approach to Cartesian constraints. To this end, we devise an algorithm that adds the Cartesian constraints directly to the projector matrix and in this way eliminates them from the reduced coordinate space in which the molecule is optimized. To analyze the performance and stability of the constrained optimization algorithm in normal coordinate space, we present constrained minimizations of small molecular systems and amino acids in gas phase as well as water employing QM/MM constrained optimizations. All calculations are performed in the framework of auxiliary density functional theory as implemented in the program deMon2k.

Barriers and enablers of vigorous intermittent lifestyle physical activity (VILPA) in physically inactive adults: a focus group study.

BACKGROUND: Vigorous Intermittent Lifestyle Physical Activity (VILPA) refers to brief bouts of vigorous intensity physical activity performed as part of daily living. VILPA has been proposed as a novel concept to expand physical activity options among the least active. As a nascent area of research, factors which impede or encourage VILPA in physically inactive adults are yet to be explored. Such information is pertinent in the design of future interventions. We examined the barriers and enablers of VILPA among physically inactive adults using the Capability, Opportunity, Motivation, Behavior (COM-B) model as a conceptual framework. METHODS: We recruited a sample of self-identified physically inactive middle-aged and older adults (N = 78) based in Australia to take part in 19 online focus groups across three age groups: young-middle (age 35-44), middle (age 45-59) and old (age 60-76). We analyzed interviews using a critical realist approach to thematic analysis. Identified barriers and enablers were subsequently mapped onto the COM-B model components. RESULTS: The data generated 6 barriers and 10 enablers of VILPA that corresponded to COM-B concepts. Barriers included physical limitations (physical capability), perceptions of aging, need for knowledge (psychological capability), environmental constraints (physical opportunity), perceptions of effort and energy, and fear (automatic motivation). Enablers included convenience, reframing physical activity as purposeful movement, use of prompts and reminders (physical opportunity), normalization of taking the active option, gamification (social opportunity), sense of achievement, health improvements, personally salient rewards (reflective motivation), identity fit, and changing from effortful deliberation to habitual action (automatic motivation). CONCLUSION: The barriers and enablers of VILPA span capability, opportunity, and motivation beliefs. Promoting the time-efficient nature and simplicity of VILPA requiring no equipment or special gym sessions, the use of prompts and reminders at opportune times, and habit formation strategies could capitalize on the enablers. Addressing the suitability of the small bouts, the development of specific guidelines, addressing safety concerns, and explicating the potential benefits of, and opportunities to do, VILPA could ameliorate some of the barriers identified. Future VILPA interventions may require limited age customization, speaking to the potential for such interventions to be delivered at scale.

How progress evaluations are used in postgraduate education with longitudinal supervisor-trainee relationships: a mixed method study.

The combination of measuring performance and giving feedback creates tension between formative and summative purposes of progress evaluations and can be challenging for supervisors. There are conflicting perspectives and evidence on the effects supervisor-trainee relationships have on assessing performance. The aim of this study was to learn how progress evaluations are used in postgraduate education with longitudinal supervisor-trainee relationships. Progress evaluations in a two-year community-pharmacy specialization program were studied with a mixed-method approach. An adapted version of the Canadian Medical Education Directives for Specialists (CanMEDS) framework was used. Validity of the performance evaluation scores of 342 trainees was analyzed using repeated measures ANOVA. Semi-structured interviews were held with fifteen supervisors to investigate their response processes, the utility of the progress evaluations, and the influence of supervisor-trainee relationships. Time and CanMEDS roles affected the three-monthly progress evaluation scores. Interviews revealed that supervisors varied in their response processes. They were more committed to stimulating development than to scoring actual performance. Progress evaluations were utilized to discuss and give feedback on trainee development and to add structure to the learning process. A positive supervisor-trainee relationship was seen as the foundation for feedback and supervisors preferred the roles of educator, mentor, and coach over the role of assessor. We found that progress evaluations are a good method for directing feedback in longitudinal supervisor-trainee relationships. The reliability of scoring performance was low. We recommend progress evaluations to be independent of formal assessments in order to minimize roles-conflicts of supervisors.

Selection tools and student diversity in health professions education: a multi-site study.

Student diversity in health professions education (HPE) can be affected by selection procedures. Little is known about how different selection tools impact student diversity across programs using different combinations of traditional and broadened selection criteria. The present multi-site study examined the chances in selection of subgroups of applicants to HPE undergraduate programs with distinctive selection procedures, and their performance on corresponding selection tools. Probability of selection of subgroups (based on gender, migration background, prior education, parental education) of applicants (N = 1935) to five selection procedures of corresponding Dutch HPE undergraduate programs was estimated using multilevel logistic regression. Multilevel linear regression was used to analyze performance on four tools: prior-education grade point average (pe-GPA), biomedical knowledge test, curriculum-sampling test, and curriculum vitae (CV). First-generation Western immigrants and applicants with a foreign education background were significantly less likely to be selected than applicants without a migration background and with pre-university education. These effects did not vary across programs. More variability in effects was found between different selection tools. Compared to women, men performed significantly poorer on CVs, while they had higher scores on biomedical knowledge tests. Applicants with a non-Western migration background scored lower on curriculum-sampling tests. First-generation Western immigrants had lower CV-scores. First-generation university applicants had significantly lower pe-GPAs. There was a variety in effects for applicants with different alternative forms of prior education. For curriculum-sampling tests and CVs, effects varied across programs. Our findings highlight the need for continuous evaluation, identifying best practices within existing tools, and applying alternative tools.

ScipionTomo: Towards cryo-electron tomography software integration, reproducibility, and validation.

Image processing in cryogenic electron tomography (cryoET) is currently at a similar state as Single Particle Analysis (SPA) in cryogenic electron microscopy (cryoEM) was a few years ago. Its data processing workflows are far from being well defined and the user experience is still not smooth. Moreover, file formats of different software packages and their associated metadata are not standardized, mainly since different packages are developed by different groups, focusing on different steps of the data processing pipeline. The Scipion framework, originally developed for SPA (de la Rosa-Trevín et al., 2016), has a generic python workflow engine that gives it the versatility to be extended to other fields, as demonstrated for model building (Martínez et al., 2020). In this article, we provide an extension of Scipion based on a set of tomography plugins (referred to as ScipionTomo hereafter), with a similar purpose: to allow users to be focused on the data processing and analysis instead of having to deal with multiple software installation issues and the inconvenience of switching from one to another, converting metadata files, managing possible incompatibilities, scripting (writing a simple program in a language that the computer must convert to machine language each time the program is run), etcetera. Additionally, having all the software available in an integrated platform allows comparing the results of different algorithms trying to solve the same problem. In this way, the commonalities and differences between estimated parameters shed light on which results can be more trusted than others. ScipionTomo is developed by a collaborative multidisciplinary team composed of Scipion team engineers, structural biologists, and in some cases, the developers whose software packages have been integrated. It is open to anyone in the field willing to contribute to this project. The result is a framework extension that combines the acquired knowledge of Scipion developers in close collaboration with third-party developers, and the on-demand design of functionalities requested by beta testers applying this solution to actual biological problems.

Cross-sectional associations of device-measured sedentary behaviour and physical activity with cardio-metabolic health in the 1970 British Cohort Study.

AIMS: This study aimed to examine the cross-sectional associations of thigh accelerometry-assessed sedentary behaviour and moderate-to-vigorous physical activity (MVPA) with cardio-metabolic health markers and prevalent diabetes in a population sample of middle-aged British adults. METHODS: Participants (n = 4892) from the age-46-to-48 wave of the 1970 British Cohort Study were fitted with a waterproofed activPAL3 micro device. Total/prolonged sedentary time, breaks and MVPA were the main exposures. We dichotomized prolonged sedentary time and MVPA based on the corresponding median, generating four combinations as categorical exposures. Outcomes comprised of diabetes and seven cardio-metabolic health markers. We used logistic regression and generalized linear models to examine independent/joint associations, conducting a minimally adjusted model including demographics and contextual covariates, and further adjusted for total sedentary time and/or MVPA as applicable. RESULTS: Each set of 10 sedentary breaks and 1 h of prolonged sedentary time were associated with HbA1c (mmol/mol) [B = -0.18 (-0.33, -0.03) and 2.35 (1.01, 3.69), respectively]. Each set of 10 sedentary breaks and 1 h of MVPA were favourably associated with diabetes [adjusted odds ratio (AOR): 0.80 (0.71, 0.99) and 0.42 (0.26, 0.67), respectively]. Joint analyses showed that only the low MVPA × long sedentary time combination had significantly higher odds for diabetes than the referent high MVPA × short sedentary time combination [AOR: 1.89 (1.17, 3.03)]. CONCLUSIONS: Each set of additional 10 sedentary breaks per day was associated with 20% lower odds for diabetes. A low physical activity level combined with long sedentary time might synergistically deteriorate cardio-metabolic health.

A European consensus statement on the use of four-factor prothrombin complex concentrate for cardiac and non-cardiac surgical patients.

Modern four-factor prothrombin complex concentrate was designed originally for rapid targeted replacement of the coagulation factors II, VII, IX and X. Dosing strategies for the approved indication of vitamin K antagonist-related bleeding vary greatly. They include INR and bodyweight-related protocols as well as fixed dose regimens. Particularly in the massively bleeding trauma and cardiac surgery patient, four-factor prothrombin complex concentrate is used increasingly for haemostatic resuscitation. Members of the Transfusion and Haemostasis Subcommittee of the European Association of Cardiothoracic Anaesthesiology performed a systematic literature review on four-factor prothrombin complex concentrate. The available evidence has been summarised for dosing, efficacy, drug safety and monitoring strategies in different scenarios. Whereas there is evidence for the efficacy of four-factor prothrombin concentrate for a variety of bleeding scenarios, convincing safety data are clearly missing. In the massively bleeding patient with coagulopathy, our group recommends the administration of an initial bolus of 25 IU.kg-1 . This applies for: the acute reversal of vitamin K antagonist therapy; haemostatic resuscitation, particularly in trauma; and the reversal of direct oral anticoagulants when no specific antidote is available. In patients with a high risk for thromboembolic complications, e.g. cardiac surgery, the administration of an initial half-dose bolus (12.5 IU.kg-1 ) should be considered. A second bolus may be indicated if coagulopathy and microvascular bleeding persists and other reasons for bleeding are largely ruled out. Tissue-factor-activated, factor VII-dependent and heparin insensitive point-of-care tests may be used for peri-operative monitoring and guiding of prothrombin complex concentrate therapy.

Burden of disease of type 2 diabetes mellitus: cost of illness and quality of life estimated using the Maastricht Study.

AIMS: To estimate the societal costs and quality of life of people with type 2 diabetes and to compare these results with those of people with normal glucose tolerance or prediabetes. METHODS: Data from 2915 individuals from the population-based Maastricht Study were included. Costs were assessed through a resource-use questionnaire completed by the participants; cost prices were based on Dutch costing guidelines. Quality of life was expressed in utilities using the Dutch EuroQol 5D-3L questionnaire and the SF-36 health survey. Based on normal fasting glucose and 2-h plasma glucose values, participants were classified into three groups: normal glucose tolerance (n = 1701); prediabetes (n = 446); or type 2 diabetes (n = 768). RESULTS: Participants with type 2 diabetes had on average 2.2 times higher societal costs than those with normal glucose tolerance (€3,006 and €1,377 per 6 months, respectively) and had lower utilities (0.77 and 0.81, respectively). No significant differences were found between participants with normal glucose tolerance and those with prediabetes. Subgroup analyses showed that higher age, being female and having two or more diabetes-related complications resulted in higher costs (P < 0.05) and lower utilities. CONCLUSIONS: This study showed that people with type 2 diabetes have substantially higher societal costs and lower quality of life than people with normal glucose tolerance. The results provide important input for future model-based economic evaluations and for policy decision-making.

Hybrid ADFT Study of the C104 and C106 IPR Isomers.

This work presents a hybrid auxiliary density functional theory (ADFT) study of the neutral and hexaanionic C104 and C106 fullerenes with the aim to determine their ground state structures. To this end, all C104 and C106 fullerene structures that obey the isolated pentagon rule (IPR) were optimized with the Perdew-Burke-Ernzerhof generalized gradient approximation followed by a single-point energy calculation with the PBE0 hybrid functional. Our studies show that this composite approach yields relative energies of giant fullerenes that are accurate to around 1 kcal/mol. As a result, the ground states of C104, C1046-, and C1066- can be assigned to the isomers 234:Cs, 821:D2, and 891:Cs, respectively. On the other hand, the energetically lowest lying IPR isomers of C106, 331:Cs, 1194:C2, 534:C1 are separated by less than 1 kcal/mol which makes an unequivocal ground state assignment by hybrid DFT methods impossible. To guide future experiments, we also report the simulated IR and Raman spectra of the most stable neutral and hexaanionic C104 and C106 fullerenes.

The role of fibrinogen and fibrinogen concentrate in cardiac surgery: an international consensus statement from the Haemostasis and Transfusion Scientific Subcommittee of the European Association of Cardiothoracic Anaesthesiology.

To date, data regarding the efficacy and safety of administering fibrinogen concentrate in cardiac surgery are limited. Studies are limited by their low sample size and large heterogeneity with regard to the patient population, by the timing of fibrinogen concentrate administration, and by the definition of transfusion trigger and target levels. Assessment of fibrinogen activity using viscoelastic point-of-care testing shortly before or after weaning from cardiopulmonary bypass in patients and procedures with a high risk of bleeding appears to be a rational strategy. In contrast, the use of Clauss fibrinogen test for determination of plasma fibrinogen level can no longer be recommended without restrictions due to its long turnaround time, high inter-assay variability and interference with high heparin levels and fibrin degradation products. Administration of fibrinogen concentrate for maintaining physiological fibrinogen activity in the case of microvascular post-cardiopulmonary bypass bleeding appears to be indicated. The available evidence does not suggest aiming for supranormal levels, however. Use of cryoprecipitate as an alternative to fibrinogen concentrate might be considered to increase plasma fibrinogen levels. Although conclusive evidence is lacking, fibrinogen concentrate does not seem to increase adverse outcomes (i.e., thromboembolic events). Large prospective multi-centre studies are needed to better define the optimal perioperative monitoring tool, transfusion trigger and target levels for fibrinogen replacement in cardiac surgery.

The association between diabetes status, HbA1c, diabetes duration, microvascular disease, and bone quality of the distal radius and tibia as measured with high-resolution peripheral quantitative computed tomography-The Maastricht Study.

In this small cross-sectional study of predominantly well-treated participants with relatively short-term type 2 diabetes duration, HbA1c > 7% (53 mmol/mol) was associated with lower cortical density and thickness and higher cortical porosity at the distal radius, lower trabecular thickness at the distal tibia, and higher trabecular number at both sites. INTRODUCTION: To examine the association between diabetes status and volumetric bone mineral density (vBMD), bone microarchitecture and strength of the distal radius and tibia as assessed with HR-pQCT. Additionally-in participants with type 2 diabetes (T2DM), to examine the association between HbA1c, diabetes duration, and microvascular disease (MVD) and bone parameters. METHODS: Cross-sectional data from 410 (radius) and 198 (tibia) participants of The Maastricht Study (mean age 58 year, 51% female). Diabetes status (normal glucose metabolism, prediabetes, or T2DM) was based on an oral glucose tolerance test and medication history. RESULTS: After full adjustment, prediabetes and T2DM were not associated with vBMD, bone microarchitecture, and strength of the radius and tibia, except for lower trabecular number (Tb.N) of the tibia (- 4%) in prediabetes and smaller cross-sectional area of the tibia (- 7%) in T2DM. In T2DM, HbA1c > 7% was associated with lower cortical vBMD (- 5%), cortical thickness (- 16%), higher cortical porosity (+ 20%) and Tb.N (+ 9%) of the radius, and higher Tb.N (+ 9%) and lower trabecular thickness (- 13%) of the tibia. Diabetes duration > 5 years was associated with higher Tb.N (+ 6%) of the radius. The presence of MVD was not associated with any bone parameters. CONCLUSIONS: In this study with predominantly well-treated T2DM participants with relatively short-term diabetes duration, inadequate blood glucose control was negatively associated with cortical bone measures of the radius. In contrast, trabecular number was increased at both sites. Studies of larger sample size are warranted for more detailed investigations of bone density and bone quality in patients with T2DM.

International consensus statement on the peri-operative management of direct oral anticoagulants in cardiac surgery.

Despite current recommendations on the management of severe peri-operative bleeding, there is no pragmatic guidance for the peri-operative monitoring and management of cardiac surgical patients taking direct oral anticoagulants. Members of the Transfusion and Haemostasis Subcommittee of the European Association of Cardiothoracic Anaesthesiology, of their own volition, performed an independent systematic review of peer-reviewed original research, review articles and case reports and developed the following consensus statement. This has been endorsed by the European Association of Cardiothoracic Anaesthesiology. In our opinion, most patients on direct oral anticoagulant therapy presenting for elective cardiac surgery can be safely managed in the peri-operative period if the following conditions are fulfilled: direct oral anticoagulants have been discontinued two days before cardiac surgery, corresponding to five elimination half-live periods; in patients with renal or hepatic impairment or a high risk of bleeding, a pre-operative plasma level of direct oral anticoagulants has been determined and found to be below 30 ng.ml-1 (currently only valid for dabigatran, rivaroxaban and apixaban). In cases where plasma level monitoring is not possible (e.g. assay was not available), discontinuation for 10 elimination half-live periods (four days) is required. For FXa inhibitors, a standard heparin-calibrated anti-Xa level of < 0.1 IU.ml-1 should be measured, indicating sufficient reduction in the anticoagulant effect. Finally, short-term bridging with heparin is not required in the pre-operative period.

Correlative light and electron microscopy reveals discrepancy between gold and fluorescence labelling.

Electron microscopy (EM) is traditionally employed as a follow-up to fluorescence microscopy (FM) to resolve the cellular ultrastructures wherein fluorescently labelled biomolecules reside. In order to translate the information derived from FM studies to EM analysis, biomolecules of interest must be identified in a manner compatible with EM. Although fluorescent signals can serve this purpose when FM is combined with EM in correlative light and electron microscopy (CLEM), the traditional immunogold labelling remains commonly used in this context. In order to investigate how much these two strategies relate, we have directly compared the subcellular localization of on-section fluorescence labelling with on-section immunogold labelling. In addition to antibody labelling of LAMP-1, bioorthogonal click labelling was used to localize soluble cysteine cathepsins or membrane-associated sialylated glycans. We reveal and characterize the existence of inherent discrepancies between the fluorescence signal and the distribution of gold particles in particular in the case of membrane-associated antigens.

Foil-hole and data image quality assessment in 3DEM: Towards high-throughput image acquisition in the electron microscope.

Automatic or semiautomatic data collection approaches on a transmission electron microscope (TEM) for Single Particle Analysis, capable of acquiring large datasets composed of only high quality images, are of great importance to obtain 3D density maps with the highest resolution possible. Typically, this task is performed by an experienced microscopist, who manually decides to keep or discard images according to subjective criteria. Therefore, this methodology is slow, intensive in human work and subjective. In this work, we propose a method to automatically or semiautomatically perform this image selection task. The approach is based on some simple, fast and effective image quality descriptors, which can be computed during acquisition, to characterize foil-hole and data images. The proposed approach has been used to evaluate the quality of different datasets consisting of foil-hole and data images obtained with a FEI Titan Krios electron microscope. The results show that the proposed method is very effective evaluating the quality of foil-hole and data images, as well as predicting the quality of the data images from the foil-hole images.

The association between glucose metabolism status, diabetes severity and a history of fractures and recent falls in participants of 50 years and older-the Maastricht Study.

In this cohort of relatively young and well-treated participants with type 2 diabetes, we found no association between diabetes status and a history of previous fractures and recent falls. Furthermore, no association between diabetes severity and previous fractures or recent falls was found. INTRODUCTION: In this study, we examined the association between glucose metabolism status and historical fractures or recent falls and the effect of diabetes severity (glucose control, insulin use, and diabetes duration) on falls and fractures in the participants with type 2 diabetes. METHODS: Cross-sectional data from 2005 participants of the Maastricht Study. Falls in the past 6 months and fractures ≥age 50 were assessed by questionnaire. Glucose metabolism status (normal glucose metabolism, impaired glucose metabolism, or type 2 diabetes) was based on the oral glucose tolerance test and medication use. RESULTS: In the completely adjusted model, the odds for a fall were not significantly higher in those with impaired glucose metabolism status (OR (95%CI) 1.28 (0.93-1.77)) or with type 2 diabetes (OR (95%CI) 1.21 (0.80-1.81)) compared with the group with normal glucose metabolism. Within the group with type 2 diabetes, there were no significant differences with regard to reported falls between participants with HbA1c >7 % (53 mmol/mol) versus HbA1c ≤7 % (OR (95%CI) 1.05 (0.58-1.90)), insulin users versus non-insulin users (OR (95%CI) 1.51 (0.79-2.89)), and with a diabetes duration >5 versus ≤5 years (OR (95%CI) 0.52 (0.46-1.47)). Similarly, neither glucose metabolism status nor diabetes severity was associated with prior fractures. CONCLUSIONS: Glucose metabolism status was not significantly associated with previous fractures and recent falls. In addition, in this cohort of relatively young and well-treated participants with type 2 diabetes, diabetes severity was not associated with previous fractures and recent falls.

Conical Fourier shell correlation applied to electron tomograms.

The resolution of electron tomograms is anisotropic due to geometrical constraints during data collection, such as the limited tilt range and single axis tilt series acquisition. Acquisition of dual axis tilt series can decrease these effects. However, in cryo-electron tomography, to limit the electron radiation damage that occurs during imaging, the total dose should not increase and must be fractionated over the two tilt series. Here we set out to determine whether it is beneficial fractionate electron dose for recording dual axis cryo electron tilt series or whether it is better to perform single axis acquisition. To assess the quality of tomographic reconstructions in different directions here we introduce conical Fourier shell correlation (cFSCe/o). Employing cFSCe/o, we compared the resolution isotropy of single-axis and dual-axis (cryo-)electron tomograms using even/odd split data sets. We show that the resolution of dual-axis simulated and cryo-electron tomograms in the plane orthogonal to the electron beam becomes more isotropic compared to single-axis tomograms and high resolution peaks along the tilt axis disappear. cFSCe/o also allowed us to compare different methods for the alignment of dual-axis tomograms. We show that different tomographic reconstruction programs produce different anisotropic resolution in dual axis tomograms. We anticipate that cFSCe/o can also be useful for comparisons of acquisition and reconstruction parameters, and different hardware implementations.

Towards the imaging of Weibel-Palade body biogenesis by serial block face-scanning electron microscopy.

Electron microscopy is used in biological research to study the ultrastructure at high resolution to obtain information on specific cellular processes. Serial block face-scanning electron microscopy is a relatively novel electron microscopy imaging technique that allows three-dimensional characterization of the ultrastructure in both tissues and cells by measuring volumes of thousands of cubic micrometres yet at nanometre-scale resolution. In the scanning electron microscope, repeatedly an image is acquired followed by the removal of a thin layer resin embedded biological material by either a microtome or a focused ion beam. In this way, each recorded image contains novel structural information which can be used for three-dimensional analysis. Here, we explore focused ion beam facilitated serial block face-scanning electron microscopy to study the endothelial cell-specific storage organelles, the Weibel-Palade bodies, during their biogenesis at the Golgi apparatus. Weibel-Palade bodies predominantly contain the coagulation protein Von Willebrand factor which is secreted by the cell upon vascular damage. Using focused ion beam facilitated serial block face-scanning electron microscopy we show that the technique has the sensitivity to clearly reveal subcellular details like mitochondrial cristae and small vesicles with a diameter of about 50 nm. Also, we reveal numerous associations between Weibel-Palade bodies and Golgi stacks which became conceivable in large-scale three-dimensional data. We demonstrate that serial block face-scanning electron microscopy is a promising tool that offers an alternative for electron tomography to study subcellular organelle interactions in the context of a complete cell.

Diagnosing attention-deficit hyperactivity disorder (ADHD) in children involved with child protection services: are current diagnostic guidelines acceptable for vulnerable populations?

Children involved with child protection services (CPS) are diagnosed and treated for attention-deficit hyperactivity disorder (ADHD) at higher rates than the general population. Children with maltreatment histories are much more likely to have other factors contributing to behavioural and attentional regulation difficulties that may overlap with or mimic ADHD-like symptoms, including language and learning problems, post-traumatic stress disorder, attachment difficulties, mood disorders and anxiety disorders. A higher number of children in the child welfare system are diagnosed with ADHD and provided with psychotropic medications under a group care setting compared with family-based, foster care and kinship care settings. However, children's behavioural trajectories change over time while in care. A reassessment in the approach to ADHD-like symptoms in children exposed to confirmed (or suspected) maltreatment (e.g. neglect, abuse) is required. Diagnosis should be conducted within a multidisciplinary team and practice guidelines regarding ADHD diagnostic and management practices for children in CPS care are warranted both in the USA and in Canada. Increased education for caregivers, teachers and child welfare staff on the effects of maltreatment and often perplexing relationship with ADHD-like symptoms and co-morbid disorders is also necessary. Increased partnerships are needed to ensure the mental well-being of children with child protection involvement.

Electron diffraction study of lipids in non-lesional stratum corneum of atopic eczema patients.

Skin barrier impairment is thought to be an important factor in the pathogenesis of atopic eczema (AE). The skin barrier is located in the stratum corneum (SC), consisting of corneocytes embedded in lipids. Ceramides, cholesterol and free fatty acids are the major lipid classes and are crucial for the skin barrier function, but their role in relation to AE is indistinct. Filaggrin is an epidermal barrier protein and common mutations in the filaggrin gene strongly predispose for AE. However, there is no strong evidence that filaggrin mutations are related to the reduced skin barrier in AE. In this study, electron diffraction is used in order to study the lipid organization of control SC and non-lesional SC of AE patients in vivo. An increased presence of the hexagonal lipid organization was observed in non-lesional SC of AE patients, indicating a less dense lipid organization. These changes correlate with a reduced skin barrier function as measured with transepidermal water loss but do not correlate with the presence of filaggrin mutations. These results are indicative for the importance of the lipid organization for a proper skin barrier function.