Determinants of circulating calcitriol in cardiovascular disease

Circulating calcitriol may contribute to the risk of cardiovascular disease (CVD), but its regulation in patients with CVD is poorly characterized. We therefore aimed to assess determinants of circulating calcitriol in these patients. We analyzed 2183 independent samples from a large cohort of patients scheduled for coronary angiography and 1727 independent samples from different other cohorts from patients with a wide range of CVDs, including heart transplant candidates, to quantify the association of different parameters with circulating calcitriol. We performed univariable and multivariable linear regression analyses using the mathematical function that fitted best with circulating calcitriol. In the multivariable analysis of the large single cohort, nine parameters remained significant, explaining 30.0 % (32.4 % after exclusion of 22 potential outliers) of the variation in circulating calcitriol (r=0.548). Log-transformed 25-hydroxyvitamin D [25(OH)D] and log-transformed glomerular filtration rate were the strongest predictors, explaining 17.6 % and 6.6 %, respectively, of the variation in calcitriol. In the analysis of the combined other cohorts, including heart transplant candidates, the multivariable model explained a total of 42.6 % (46.1 % after exclusion of 21 potential outliers) of the variation in calcitriol (r=0.653) with log-transformed fibroblast growth factor-23 and log-transformed 25(OH)D explaining 29.0 % and 6.2 %, respectively. Circulating 25(OH)D was positively and FGF-23 inversely associated with circulating calcitriol. Although significant, PTH was only a weak predictor of calcitriol in both analyses (<2.5 %). In patients with CVD, FGF-23 and 25(OH)D are important independent determinants of circulating calcitriol. The relative importance of these two parameters may vary according to CVD severity. Future studies should focus on the clinical importance of regulating circulating calcitriol by different parameters.

Use of Multiple-Choice Items in Summative Examinations: Questionnaire Survey Among German Undergraduate Dental Training Programs

Background

Multiple-choice examinations are frequently used in German dental schools. However, details regarding the used item types and applied scoring methods are lacking.

Objective

This study aims to gain insight into the current use of multiple-choice items (ie, questions) in summative examinations in German undergraduate dental training programs.

Methods

A paper-based 10-item questionnaire regarding the used assessment methods, multiple-choice item types, and applied scoring methods was designed. The pilot-tested questionnaire was mailed to the deans of studies and to the heads of the Department of Operative/Restorative Dentistry at all 30 dental schools in Germany in February 2023. Statistical analysis was performed using the Fisher exact test (P<.05).

Results

The response rate amounted to 90% (27/30 dental schools). All respondent dental schools used multiple-choice examinations for summative assessments. Examinations were delivered electronically by 70% (19/27) of the dental schools. Almost all dental schools used single-choice Type A items (24/27, 89%), which accounted for the largest number of items in approximately half of the dental schools (13/27, 48%). Further item types (eg, conventional multiple-select items, Multiple-True-False, and Pick-N) were only used by fewer dental schools (≤67%, up to 18 out of 27 dental schools). For the multiple-select item types, the applied scoring methods varied considerably (ie, awarding [intermediate] partial credit and requirements for partial credit). Dental schools with the possibility of electronic examinations used multiple-select items slightly more often (14/19, 74% vs 4/8, 50%). However, this difference was statistically not significant (P=.38). Dental schools used items either individually or as key feature problems consisting of a clinical case scenario followed by a number of items focusing on critical treatment steps (15/27, 56%). Not a single school used alternative testing methods (eg, answer-until-correct). A formal item review process was established at about half of the dental schools (15/27, 56%).

Conclusions

Summative assessment methods among German dental schools vary widely. Especially, a large variability regarding the use and scoring of multiple-select multiple-choice items was found.

Prodromal or mild Alzheimer's disease: Influence of neuropsychiatric symptoms and premordid personality on caregivers' burden

OBJECTIVE

In Alzheimer's disease (AD), the burden on caregivers is influenced by various factors, including the stage of disease progression and neuropsychiatric symptoms (NPS). To date, there has been limited research examining how patient's premorbid personality could affect this burden. The objective of this study was to investigate the impact of both premorbid personality and NPS in individuals with prodromal to mild AD on their caregivers' burden.

METHOD

One hundred eighty participants with prodromal or mild AD drown from the PACO (in French: Personnalité Alzheimer COmportement) cohort were included. Personality was assessed by the Revised NEO Personality Inventory (NEO-PI-R). Neuropsychiatric symptoms were measured with the short version of the Neuropsychiatric Inventory (NPI-Q), and caregiver burden was evaluated with the Zarit burden scale. Relationships between personality, Neuro-Psychiatric Inventory (NPI) scores, and caregiver burden were determined using multivariate linear regressions controlled for age, sex, educational level, and Mini Mental State Examination.

RESULTS

The total NPI score was related to increased burden (beta = 0.45; p < 0.001). High level of neuroticism (beta = 0.254; p = 0.003) et low level of conscientiousness (beta = - 0.233; p = 0.005) were associated higher burden. Extraversion (beta = -0.185; p = 0.027) and conscientiousness (beta = -0.35; p = 0.006) were negatively associated with burden. In contrast, neuroticism, openness and agreeableness were not correlated with burden. When adjusted on total NPI score, the relationship between extraversion and conscientiousness didn't persist.

CONCLUSION

Our results suggest that premorbid personality of patients with prodromal to mild Alzheimer influence caregivers's burden, with a protective effect of a high level of extraversion and conscientiousness.

Use of Multiple-Select Multiple-Choice Items in a Dental Undergraduate Curriculum: Retrospective Study Involving the Application of Different Scoring Methods

BACKGROUND

Scoring and awarding credit are more complex for multiple-select items than for single-choice items. Forty-one different scoring methods were retrospectively applied to 2 multiple-select multiple-choice item types (Pick-N and Multiple-True-False [MTF]) from existing examination data.

OBJECTIVE

This study aimed to calculate and compare the mean scores for both item types by applying different scoring methods, and to investigate the effect of item quality on mean raw scores and the likelihood of resulting scores at or above the pass level (≥0.6).

METHODS

Items and responses from examinees (ie, marking events) were retrieved from previous examinations. Different scoring methods were retrospectively applied to the existing examination data to calculate corresponding examination scores. In addition, item quality was assessed using a validated checklist. Statistical analysis was performed using the Kruskal-Wallis test, Wilcoxon rank-sum test, and multiple logistic regression analysis (P<.05).

RESULTS

We analyzed 1931 marking events of 48 Pick-N items and 828 marking events of 18 MTF items. For both item types, scoring results widely differed between scoring methods (minimum: 0.02, maximum: 0.98; P<.001). Both the use of an inappropriate item type (34 items) and the presence of cues (30 items) impacted the scoring results. Inappropriately used Pick-N items resulted in lower mean raw scores (0.88 vs 0.93; P<.001), while inappropriately used MTF items resulted in higher mean raw scores (0.88 vs 0.85; P=.001). Mean raw scores were higher for MTF items with cues than for those without cues (0.91 vs 0.8; P<.001), while mean raw scores for Pick-N items with and without cues did not differ (0.89 vs 0.90; P=.09). Item quality also impacted the likelihood of resulting scores at or above the pass level (odds ratio ≤6.977).

CONCLUSIONS

Educators should pay attention when using multiple-select multiple-choice items and select the most appropriate item type. Different item types, different scoring methods, and presence of cues are likely to impact examinees' scores and overall examination results.

Vitamin D Metabolites: Analytical Challenges and Clinical Relevance

Recent research activities have provided new insights in vitamin D metabolism in various conditions. Furthermore, substantial progress has been made in the analysis of vitamin D metabolites and related biomarkers, such as vitamin D binding protein. Liquid chromatography tandem mass spectrometric (LC-MS/MS) methods are capable of accurately measuring multiple vitamin D metabolites in parallel. Nevertheless, only 25(OH)D and the biologically active form 1,25(OH)2D are routinely measured in clinical practice. While 25(OH)D remains the analyte of choice for the diagnosis of vitamin D deficiency, 1,25(OH)2D is only recommended in a few conditions with a dysregulated D metabolism. 24,25(OH)2D, free and bioavailable 25(OH)D, and the vitamin D metabolite ratio (VMR) have shown promising results, but technical pitfalls in their quantification, limited clinical data and the lack of reference values, impede their use in clinical practice. LC-MS/MS is the preferred method for the measurement of all vitamin D related analytes as it offers high sensitivity and specificity. In particular, 25(OH)D and 24,25(OH)2D can accurately be measured with this technology. When interpreted together, they seem to provide a functional measure of vitamin D metabolism beyond the analysis of 25(OH)D alone. The determination of VDBP, free and bioavailable 25(OH)D is compromised by unresolved analytical issues, lacking reference intervals and insufficient clinical data. Therefore, future research activities should focus on analytical standardization and exploration of their clinical value. This review provides an overview on established and new vitamin D related biomarkers including their pathophysiological role, preanalytical and analytical aspects, expected values, indications and influencing conditions.

Review: cellularity in bone marrow autografts for bone and fracture healing

The use of autografts, as primary cell and tissue source, is the current gold standard approach to treat critical size bone defects and nonunion defects. The unique mixture of the autografts, containing bony compartments and bone marrow (BM), delivers promising results. Although BM mesenchymal stromal cells (BM-MSCs) still represent a major target for various healing approaches in current preclinical research and respective clinical trials, their occurrence in the human BM is typically low. In vitro expansion of this cell type is regulatory challenging as well as time and cost intensive. Compared with marginal percentages of resident BM-MSCs in BM, BM mononuclear cells (BM-MNCs) contained in BM aspirates, concentrates, and bone autografts represent a readily available abundant cell source, applicable within hours during surgical procedures without the need for time-consuming and regulatory challenging cell expansion. This benefit is one reason why autografting has become a clinical standard procedure. However, the exact anatomy and cellularity of BM-MNCs in humans, which is strongly correlated to their unique mode of action and wide application range remains to be elucidated. The aim of this review was to present an overview of the current knowledge on these specific cell types found in human BM, emphasize the contribution of BM-MNCs in bone healing, highlight donor site dependence, and discuss limitations in the current isolation and subsequent characterization procedures. Hereby, the most recent and relevant examples of human BM-MNC cell characterization, flow cytometric analyses, and findings are summarized, with a strong focus on bone therapy.

Role of Vitamin K in Bone and Muscle Metabolism

Vitamin K, a cofactor for the γ-glutamyl carboxylase enzyme, is required for the post-translational activation of osteocalcin and matrix Gla protein, which play a key role in bone and muscle homeostasis. In vivo and in vitro models for osteoporosis and sarcopenia suggest the vitamin K could exert a positive effect in both conditions. In bone, it increases osteoblastogenesis, whilst decreases osteoclast formation and function. In muscle, it is associated with increased satellite cell proliferation and migration and might play a role in energy metabolism. Observational trials suggest that high levels of vitamin K are associated with increased bone mineral density and reduced fracture risk. However, interventional studies for vitamin K supplementation yielded conflicting results. Clinical trials in sarcopenia suggest that vitamin K supplementation could improve muscle mass and function. One of the main limitations on the vitamin K studies are the technical challenges to measure its levels in serum. Thus, they are obtained from indirect sources like food questionnaires, or levels of undercarboxylated proteins, which can be affected by other environmental or biological processes. Although current research appoints to a beneficial effect of vitamin K in bone and muscle, further studies overcoming the current limitations are required in order to incorporate this supplementation in the clinical management of patients with osteosarcopenia.

Immune and stem cell compartments of acetabular and femoral bone marrow in hip osteoarthritis patients

OBJECTIVE

Hip osteoarthritis (OA) affects all components of the osteochondral unit, leading to bone marrow (BM) lesions, and unknown consequences on BM cell functionality. We analyzed the cellular composition in OA-affected acetabula compared to proximal femur shafts obtained of hip OA patients to reveal yet not explored immune and stem cell compartments.

DESIGN

Combining flow cytometry, cellular assays and transcription analyses, we performed extensive ex vivo phenotyping of acetabular BM cells from 18 hip OA patients, comparing them with their counterparts from patient-matched femoral shaft BM samples. Findings were related to differences in skeletal sites and age.

RESULTS

Acetabular BM had a greater frequency of T-lymphocytes, non-hematopoietic cells and colony-forming units fibroblastic potential than femoral BM. The incidence of acetabular CD45⁺CD3⁺ T-lymphocytes increased (95% CI: 0.1770 to 0.0.8416), while clonogenic hematopoietic progenitors declined (95% CI: -0.9023 to -0.2399) with age of patients. On the other side, in femoral BM, we observed higher B-lymphocyte, myeloid and erythroid cell frequencies. Acetabular mesenchymal stromal cells (MSCs) showed a senescent profile associated with the expression of survival and inflammation-related genes. Efficient osteogenic and chondrogenic differentiation was detected in acetabular MSCs, while adipogenesis was more pronounced in their femoral counterparts.

CONCLUSION

Our results suggest that distinctions in BM cellular compartments and MSCs may be due to the influence of the OA-stressed microenvironment, but also acetabular vs femoral shaft-specific peculiarities cannot be excluded. These results bring new knowledge on acetabular BM cell populations and may be addressed as novel pathogenic mechanisms and therapeutic targets in OA.

Development and characterization of a predictive microCT-based non-union model in Fischer F344 rats

INTRODUCTION

Non-unions remain a clinical problem and are characterised by the failure to heal after a defined period of time. Current preclinical non-union models apply a wide variety of techniques to diminish intrinsic healing potential deviating from the clinical situation. The aim of this study was to develop and characterise a non-union model in rats using internal plate fixation without the need for additional healing insults, whereby bone healing can be longitudinally assessed using microCT. It was hypothesized that healing/non-unions can be accurately predicted at early time points by microCT.

MATERIALS AND METHODS

Female, skeletally mature Fischer F344 rats received a 2 mm or 1 mm femoral osteotomy, stabilized with either a 2 mm thick plate or a 1.25 mm thick plate. Healing was monitored by microCT over 14 weeks and histological analysis at euthanasia. The mechanical environment was characterised using finite element (FE) modelling and biomechanical testing.

RESULTS

The majority of animals receiving the 2 mm thick plate displayed poor healing responses in both the 2 mm and 1 mm defect size groups. Bone and cartilage formation were markedly improved using the 1.25 mm thick plate. MicroCT could accurately predict bone forming capacity at early time points (3-4 weeks).

CONCLUSIONS

The 2 mm thick plating system confers poor healing responses in female Fischer F344 rats, comparable to atrophic non-unions. By reducing plate thickness to increase interfragmentary strain within the defect site healing is improved, leading to borderline healing situations or increased abundance of cartilage tissue present in the defect site with ultimate failure to bridge the defect (hypertrophic non-union). Furthermore, microCT can reliably identify delayed/non-healing animals within 4 weeks, thereby allowing their selective targeting for the testing of novel, clinically relevant treatment strategies in different clinical situations aimed at restoring impaired bone healing.

Intranasal oxytocin has sympathoexcitatory effects on vascular tone in healthy males

Oxytocin appears to be involved in the neuroendocrine regulation of sympathetic blood pressure (BP) homeostasis. In animals, intracerebral administration of oxytocin induces BP-relevant sympathetic activation. In humans, central nervous effects of oxytocin on BP regulation remain unclear. Intranasal administration supposedly delivers oligopeptides such as oxytocin directly to the brain. We investigated the effects of intranasal oxytocin on sympathetic vascular baroreflex function in humans using microneurographic techniques. In a balanced, double-blind crossover design, oxytocin or placebo was administered intranasally to 12 lean, healthy males (age 25 ± 4 yr). Muscle sympathetic nerve activity (MSNA) was assessed microneurographically before (presubstance), 30-45 min (postsubstance I), and 105-120 min (postsubstance II) after oxytocin administration. Baroreflex was challenged via graded infusions of vasoactive drugs, and correlation of BP with MSNA and heart rate (HR) defined baroreflex function. Experiments were conducted in the afternoon after a 5-h fasting period. After oxytocin, resting MSNA (burst rate and total activity) showed significant net increases from pre to postsubstance II compared with placebo [Δincrease = +4.3 ± 1.2 (oxytocin) vs. +2.2 ± 1.4 bursts/min (placebo), ANOVA; P < 0.05; total activity = 184 ± 11.5% (oxytocin) vs. 121 ± 14.3% (placebo), ANOVA; P = 0.01). This was combined with a small but significant net increase in resting diastolic BP, whereas systolic and mean arterial BP or HR as well as baroreflex sensitivity at vasoactive drug challenge were not altered. Intranasally administered oxytocin induced vasoconstrictory sympathoactivation in healthy male humans. The concomitant increase of diastolic BP was most likely attributable to increased vascular tone. This suggests oxytocin-mediated upward resetting of the vascular baroreflex set point at centers superordinate to the mere baroreflex-feedback loop.

[Video presentations for examination questions in psychiatry : A pilot study]

BACKGROUND

The master plan for medical studies 2020 (MM2020) aims at a restructuring of medical education. The examinations should represent the key element of the evaluation and electronically supported examination methods will be expanded.

OBJECTIVE

Videos of actors displaying psychopathological phenomena were implemented into examination questions for the first time through the use of an electronically supported examination (e-examination) and therefore in accordance with the aims of MM2020.

METHODS

A total of four multiple choice (MC) questions referencing short video representations of different psychopathological phenomena were formulated and shown to medical students within an e‑examination. The MC questions were evaluated with respect to scientific quality criteria and the medical students were asked to fill in a questionnaire regarding their evaluation of the content and format of the MC questions after participating in the examination.

RESULTS

The MC video questions were presented to the students directly following the regular e‑examination of the teaching module in psychiatry. Out of 69 students 60 participated in the study. The MC video questions had a high level of acceptance and positive evaluation by the students. With respect to the scientific quality criteria, the MC questions showed heterogeneous results.

CONCLUSION

Due to the versatile applicability and high efficiency, MC questions will continue to play an important role in medical examinations. In accordance with the aims of MM2020, it could be shown that psychiatric knowledge can be examined in a competence-oriented manner and with a practical orientation by means of video presentations in an e‑examination. A broader application of video presentations could complement electronically supported examinations in the discipline of psychiatry.

OP0239 WHY DOES ALCOHOL INHIBIT ARTHRITIS? - AN EXPLANATION OF THE MECHANISM OF ARTHRITIS INHIBITION BY ETHANOL

Background:

Alcohol consumption has emerged as consistent protective factor for the development of autoimmune diseases such as rheumatoid arthritis (RA). The underlying mechanism for this tolerance-inducing effect of alcohol, however, is unknown.

Objectives:

To understand the anti-arthritogenic effect of alcohol

Methods:

The immune-regulatory properties of alcohol consumption in vivo were tested in the collagen-induced arthritis (CIA) and serum-induced arthritis (SIA) model as well as after immunization with T cell- dependent (NP-CGG) and independent (TNP-FICOLL) antigens. Additional experiments in vivo experiments in these models were done with acetate- the metabolite of ethanol. The models were analysed for T- cell lineage and plasma cell differentiation, germinal centre formation and IgG levels and sialylation. Molecular expression of T follicular helper cell (TFH) activation such as IL-21, Bcl-6 and PD-1, as well as TFH: B cell conjugates were also assessed. Furthermore, TFH cells were generated in vitro, exposed to ethanol or acetate and tested for IL-21 production, PD1 expression and conjugate formation with B cells.

Results:

Ethanol exposure significantly inhibited arthritis in the active adaptive immunity-driven model of arthritis (CIA) but not in the passive innate immunity-driven model (STA) suggesting that the immune suppressive effect of alcohol is based on interference of T- and B- cell activation. In line ethanol and even more its metabolite acetate, suppressed T cell dependent antibody formation after NP-CGG immunization, while T cell independent antibody formation after TNP-FICOLL immunization was not suppressed. Ethanol, as well as its metabolite acetate, specifically altered the functional state of T follicular helper (TFH) cells in vitro and in vivo, thereby exerting immune regulatory and tolerance-inducing properties. Alcohol-exposed mice showed reduced Bcl6 and PD-1 expression as well as interleukin (IL)-21 production by TFH cells, preventing proper spatial organization of TFH cells to form TFH: B cell conjugates in the germinal centre. This effect of alcohol on TFHcells was associated with impaired autoantibody formation, higher sialylation of autoantibodies and less arthritis. In accordance, overexpression of IL-21 in vivo completely reversed the immune regulatory effects of alcohol.

Conclusion:

In summary, these data provide a new mechanistic explanation for the immune regulatory and tolerance-inducing effect of alcohol consumption in arthritis.

Acknowledgments:

Funden by DFG-FOR2886, DFG–CRC1181, Staedtler foundation, Johannes und Frieda Marohn-Stiftung, Else Kröner-Fresenius foundation, Interdisciplinary Centre for Clinical Research, Erlangen, BMBF-MASCARA, IMI funded project RTCure.

Disclosure of Interests:

Vugar Azizov: None declared, Maria V Sokolova: None declared, Kerstin Sarter: None declared, Vladimir Temchura: None declared, Ulrike Steffen (née Harre): None declared, Martin Herrmann: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Mario Zaiss: None declared

[COVID-19 pandemic: structured expansion of ventilation capacities using home respirators]

Due to the current COVID-19 pandemic there is a need for a rapid increase in intensive care and ventilation capacities. Delivery times for additional intensive care respirators are currently not foreseeable. An option to increase ventilation capacities not only for COVID-19, but for all patients requiring mechanical ventilation is to use home respirators. Home respirators are turbine respirators, so they can usually be operated without high-pressure oxygen connections and can therefore also be used in areas outside the classical intensive care medical infrastructure. Due to their limited technical features, home respirators are not suitable for the treatment of severely affected patients but can be used for weaning after respiratory improvement, which means that intensive care respirators are available again more quickly. Respiratory therapists are specially trained nurses or therapists in the field of out of hospital ventilation and can independently use home ventilation respirators, for example for weaning in the intensive care unit. Thus, they relieve intensive care nursing staff in the pandemic. Due to the COVID-19 pandemic medical students from the Oldenburg University are currently being trained in operating home respirators to provide basic support in the hospital if necessary.

Complex food webs coincide with high genetic potential for chemolithoautotrophy in fractured bedrock groundwater

Groundwater ecosystems face the challenge of energy limitation due to the absence of light-driven primary production. Lack of space and low oxygen availability might further contribute to generally assumed low food web complexity. Chemolithoautotrophy provides additional input of carbon within the subsurface, however, we still do not understand how abundances of chemolithoautotrophs, differences in surface carbon input, and oxygen availability control subsurface food web complexity. Using a molecular approach, we aimed to disentangle the different levels of potential trophic interactions in oligotrophic groundwater along a hillslope setting of alternating mixed carbonate-/siliciclastic bedrock with contrasting hydrochemical conditions and hotspots of chemolithoautotrophy. Across all sites, groundwater harbored diverse protist communities including Ciliophora, Cercozoa, Centroheliozoa, and Amoebozoa but correlations with hydrochemical parameters were less pronounced for eukaryotes compared to bacteria. Ciliophora-affiliated reads dominated the eukaryotic data sets across all sites. DNA-based evidence for the presence of metazoan top predators such as Cyclopoida (Arthropoda) and Stenostomidae (Platyhelminthes) was only found at wells where abundances of functional genes associated with chemolithoautotrophy were 10-100 times higher compared to wells without indications of these top predators. At wells closer to recharge areas with presumably increased inputs of soil-derived substances and biota, fungi accounted for up to 85% of the metazoan-curated eukaryotic sequence data, together with a low potential for chemolithoautotrophy. Although we did not directly observe higher organisms, our results point to the existence of complex food webs with several trophic levels in oligotrophic groundwater. Chemolithoautotrophy appears to provide strong support to more complex trophic interactions, feeding in additional biomass produced by light-independent CO₂-fixation.

Decision making under uncertainty in a quasi realistic binary decision task - An fMRI study

Approaching real life decision making through Quasi Realistic Decision Making may increase the ecological validity of decision making experiments. This could help narrow the gap between laboratory settings and observations in real world contexts and thus allow for generalization of laboratory results to everyday life. A binary decision task with quasi realistic context and stimuli was created to investigate neural processing of certain and uncertain decision making, using functional Magnetic Resonance Imaging. On the basis of behavioral data (consistency of decisions in identical contexts), trials with uncertain and certain decision making were identified. This allowed for comparing uncertain and certain conditions, and contrasting each condition with a low level baseline (i.e., between trial fixation dot). A Conjunction analysis between contrasts of uncertainty versus baseline and certainty versus baseline indicated a large overlap of neural network recruitment distributed in bilateral middle frontal, medial frontal, inferior parietal, occipito-temporal, and medio-temporal areas, and the cingulate cortex. While basic neural processing principles in uncertain and certain contexts were comparable, the direct contrast revealed activation foci in middle cingulate and in frontal and parietal areas. The quasi realistic approach revealed a common network for decision making which is modulated by uncertainty.

Peripancreatic abscess supported by Bordetella hinzii

We report a novel case of an infection with Bordetella hinzii, a pathogen usually detected in poultry, supporting a peripancreatic abscess formation as a complication of an acute necrotizing pancreatitis.

Contributing factors to quality of life after vertebral artery dissection: a prospective comparative study

BACKGROUND

Vertebral artery dissection (VAD) may cause cerebral ischemia and impair quality of life (QOL) despite of good functional outcome. The aim of this study was the multimodal analysis of patient characteristics after VAD to identify contributing factors.

METHODS

In an exploratory study, 34 consecutive patients with first-ever spontaneous VAD were prospectively examined in comparison to 38 patients with cerebral ischemia without dissection and 25 stroke mimics as control groups. Multimodal assessment was performed for clinical, neurological, cognitive, psychological and radiological data at baseline and for QOL, functional outcome, and stress symptoms by questionnaire at six months follow-up. Subgroup analysis stratified for QOL by Stroke Specific Quality of Life Scale (SS-QOL) were done for patients with good functional outcome (modified Ranking Scale (mRS) scoring 0-2). Predictors for QOL at follow-up were analyzed by regression model.

RESULTS

88.2% of patients with VAD suffered from acute cerebral ischemia. Thirteen of 32 VAD patients (40.6%) rated QOL at follow-up as bad (SS-QOL score ≤ 3.9) despite of good functional outcome (mRS score 0-2). Subgroup analysis yielded significantly higher scores for posttraumatic stress symptoms (p = 0.002) in this subgroup. Posttraumatic stress symptoms, severity of neurological disorders, and impaired neuropsychological baseline performance proved to be independent predictors for reduced QOL at follow-up according to regression analysis.

CONCLUSION

VAD leads to impaired QOL at 6 months follow-up due to multiple factors. The data suggest that posttraumatic stress symptoms are of significant importance for the QOL after VAD. Clinical monitoring should address this topic to make timely treatment possible.

New record of the invasive snail Melanoides tuberculata (Gastropoda, Thiaridae) - Ceará State, Brazil

Melanoides tuberculata is a freshwater gastropod native to Africa and Asia, and currently presents distributed worldwide. The first record of Melanoides tuberculata in South America occurred in Brazil, in the city of Santos, state of São Paulo, in 1967. Therefore, the objective of the present study is to report the occurrence of Melanoides tuberculata for Banana Lagoon and to characterize the current population situation. The gastropods were collected through direct visualization of shells, morphometric measurements of Melanoides tuberculata shells were determined using a digital caliper. After identifying the gastropod and its first distribution in the area, a preliminary descriptive analysis of the population was carried out. The gastropods were classified by grouping the individuals into four classes according to the shell width (mm). This is the first record of the occurrence of Melanoides tuberculata, in Banana Lagoon, Caucaia municipality, Ceará state, Northeast Brazil, being the largest specimen cited in the literature (33.77 mm) and 92.65% of the gastropods present in sizes above the first reproduction stages.

Approaches to mimic the complexity of the skeletal mesenchymal stem/stromal cell niche in vitro

Mesenchymal stem/stromal cells (MSCs) are an essential element of most modern tissue engineering and regenerative medicine approaches due to their multipotency and immunoregulatory functions. Despite the prospective value of MSCs for the clinics, the stem cells community is questioning their developmental origin, in vivo localization, identification, and regenerative potential after several years of far-reaching research in the field. Although several major progresses have been made in mimicking the complexity of the MSC niche in vitro, there is need for comprehensive studies of fundamental mechanisms triggered by microenvironmental cues before moving to regenerative medicine cell therapy applications. The present comprehensive review extensively discusses the microenvironmental cues that influence MSC phenotype and function in health and disease - including cellular, chemical and physical interactions. The most recent and relevant illustrative examples of novel bioengineering approaches to mimic biological, chemical, and mechanical microenvironmental signals present in the native MSC niche are summarized, with special emphasis on the forefront techniques to achieve bio-chemical complexity and dynamic cultures. In particular, the skeletal MSC niche and applications focusing on the bone regenerative potential of MSC are addressed. The aim of the review was to recognize the limitations of the current MSC niche in vitro models and to identify potential opportunities to fill the bridge between fundamental science and clinical application of MSCs.

Volumetric gray matter measures of amygdala and accumbens in childhood overweight/obesity

Objectives

Neuroimaging data suggest that pediatric overweight and obesity are associated with morphological alterations in gray matter (GM) brain structures, but previous studies using mainly voxel-based morphometry (VBM) showed inconsistent results. Here, we aimed to examine the relationship between youth obesity and the volume of predefined reward system structures using magnetic resonance (MR) volumetry. We also aimed to complement volumetry with VBM-style analysis.

Methods

Fifty-one Caucasian young subjects (32 females; mean age: 13.8±1.9, range: 10.2–16.5 years) were included. Subjects were selected from a subsample of the I.Family study examined in the Hungarian center. A T₁-weighted 1 mm³ isotropic resolution image was acquired. Age- and sex-standardized body mass index (zBMI) was assessed at the day of MRI and ~1.89 years (mean±SD: 689±188 days) before the examination. Obesity related GM alterations were investigated using MR volumetry in five predefined brain structures presumed to play crucial roles in body weight regulation (hippocampus, amygdala, accumbens, caudate, putamen), as well as whole-brain and regional VBM.

Results

The volumes of accumbens and amygdala showed significant positive correlations with zBMI, while their GM densities were inversely related to zBMI. Voxel-based GM mass also showed significant negative correlation with zBMI when investigated in the predefined amygdala region, but this relationship was mediated by GM density.

Conclusions

Overweight/obesity related morphometric brain differences already seem to be present in children/adolescents. Our work highlights the disparity between volume and VBM-derived measures and that GM mass (combination of volume and density) is not informative in the context of obesity related volumetric changes. To better characterize the association between childhood obesity and GM morphometry, a combination of volumetric segmentation and VBM methods, as well as future longitudinal studies are necessary. Our results suggest that childhood obesity is associated with enlarged structural volumes, but decreased GM density in the reward system.

Dental Students' Factual and Procedural Knowledge Retention in Operative Dentistry in a Clinical Dental Curriculum

The aim of this study was to evaluate dental students' retention of factual and procedural knowledge gained in a preclinical course in operative dentistry during a clinical dental curriculum. In 2017, all 157 seventh- to tenth-semester dental students at a dental school in Germany were asked to repeat the same written examination performed at the end of the preclinical course in the sixth semester. The examinations consisted of 30 multiple-choice questions covering factual and procedural knowledge. The percentage of correctly answered questions per exam and differences in correct answers between the original examination and the re-examination (per question) were analyzed. Students were also asked to self-rate their percentage of correctly answered questions and their knowledge in various disciplines of operative dentistry at the times of the original examination and the re-examination. After exclusions, data were analyzed for 129 students, for a participation rate of 82%. For the seventh- and tenth-semester students, the results on the original examination and the re-examination were not significantly different, while the eighth- and ninth-semester students performed significantly better on the original examination than the re-examination. In all semesters, procedural knowledge remained stable between the original examination and the re-examination, while factual knowledge decreased slightly. Their performance on the original examination was underestimated by the eighth- and ninth-semester students. All the students underestimated their performance on the re-examination. Students mostly rated their knowledge level significantly higher on the original examination than on the re-examination. Overall, this study found that factual and procedural knowledge gained in a preclinical course in operative dentistry was not increased during the clinical dental curriculum.