Rigidity of unilateral external fixators-A biomechanical study

Introduction: External fixation is the primary choice of temporary fracture stabilisation for specific polytrauma patients. Adequate initial fracture healing requires sufficient stability at the fracture site. The purpose of this study was to compare the rigidity of the Dynafix DFS (R) Standard Fixator (4 joints) with the Orthofix ProCallus Fixator (R) (2 joints), which differ in possibilities for adapting the configuration for clinical needs. Materials and methods: Both devices were tested 10 times in a standardised model. In steps of 10 N, loading was increased to a maximum of 160 N in parallel, transversal and axial direction (distraction and compression). Translation resultant and rotation resultant were calculated. Results: With a force of 100 N in parallel direction the mean translation resultant (Tr(mean)) of the Dynafix DFS (R) Standard Fixator (6.65 +/- 1.43 mm) was significantly higher than the ProCallus Fixator (R) (3.29 +/- 0.83 mm, p < 0.001; Student's t-test). With a maximum load of 60 N in transverse direction the Tr(mean) of the Dynafix DFS (R) Standard Fixator was significantly lower (8.14 +/- 1.20 mm versus 9.83 +/- 0.63 mm, p < 0.005). Translation was significantly higher with the Dynafix DFS Conclusions: Both fixators were most sensitive to transverse forces. The Dynafix DFS (R) Standard Fixator was less rigid with parallel and axial forces, whereas transverse forces and rotation at distraction forces favoured the Dynafix DFS (R) Standard Fixator. Repeated heavy loading did not influence the rigidity of both devices. (C) 2011 Elsevier Ltd. All rights reserved

Rigidity of unilateral external fixators-A biomechanical study

Introduction: External fixation is the primary choice of temporary fracture stabilisation for specific polytrauma patients. Adequate initial fracture healing requires sufficient stability at the fracture site. The purpose of this study was to compare the rigidity of the Dynafix DFS (R) Standard Fixator (4 joints) with the Orthofix ProCallus Fixator (R) (2 joints), which differ in possibilities for adapting the configuration for clinical needs. Materials and methods: Both devices were tested 10 times in a standardised model. In steps of 10 N, loading was increased to a maximum of 160 N in parallel, transversal and axial direction (distraction and compression). Translation resultant and rotation resultant were calculated. Results: With a force of 100 N in parallel direction the mean translation resultant (Tr(mean)) of the Dynafix DFS (R) Standard Fixator (6.65 +/- 1.43 mm) was significantly higher than the ProCallus Fixator (R) (3.29 +/- 0.83 mm, p < 0.001; Student's t-test). With a maximum load of 60 N in transverse direction the Tr(mean) of the Dynafix DFS (R) Standard Fixator was significantly lower (8.14 +/- 1.20 mm versus 9.83 +/- 0.63 mm, p < 0.005). Translation was significantly higher with the Dynafix DFS Conclusions: Both fixators were most sensitive to transverse forces. The Dynafix DFS (R) Standard Fixator was less rigid with parallel and axial forces, whereas transverse forces and rotation at distraction forces favoured the Dynafix DFS (R) Standard Fixator. Repeated heavy loading did not influence the rigidity of both devices. (C) 2011 Elsevier Ltd. All rights reserved

Implementation of ultra-hypofractionated radiotherapy schedules for breast cancer during the COVID-19 pandemic in the Netherlands

Background and purpose: The COVID-19 pandemic resulted in an accelerated recommendation to use five-fraction radiotherapy schedules, according to the FAST- and FAST-Forward trial. In this study, trends in the use of different radiotherapy schedules in the Netherlands were studied, as well as the likelihood of receiving five fractions. Materials and methods: Data from the NABON Breast Cancer Audit-Radiotherapy and Netherlands Cancer Registry was used. Women receiving radiotherapy for their primary invasive breast cancer or DCIS between 01–01-2020 and 31–12-2021 were included. Logistic regression was used to investigate the association between patient-, tumour-, treatment-, and radiotherapy institution-related characteristics and the likelihood of receiving five fractions in tumours meeting the FAST and FAST-Forward criteria. Results: Detailed information about radiotherapy treatment was available for 9,392 tumours. Shortly after the start of the COVID-19 pandemic, i.e. April 2020, 19% of the tumours being treated with radiotherapy received five fractions of 5.2 or 5.7 Gray (Gy). While only 3% of the tumours received five fractions in March 2020. The usage of five fractions increased to 26% in December 2021. Partial breast irradiation, compared to whole breast irradiation, was significantly associated with the administration of five fractions, as well as radiotherapy delivered in an academic radiotherapy institution compared to an independent institution. Conclusion: The start of the COVID-19 pandemic was associated with the early use of ultra-hypofractionated radiotherapy schedules. After publication of the trials, and mainly after the recommendation by the national radiotherapy society, the implementation further increased. These schedules were not yet used in all patients meeting the eligibility criteria for the FAST- or FAST-Forward trial.</p

Risk of Cerebral Venous Thrombosis in Obese Women.

IMPORTANCE Obesity is a risk factor for deep vein thrombosis of the leg and pulmonary embolism. To date, however, whether obesity is associated with adult cerebral venous thrombosis (CVT) has not been assessed. OBJECTIVE To assess whether obesity is a risk factor for CVT. DESIGN, SETTING, AND PARTICIPANTS A case-control study was performed in consecutive adult patients with CVT admitted from July 1, 2006 (Amsterdam), and October 1, 2009 (Berne), through December 31, 2014, to the Academic Medical Center in Amsterdam, the Netherlands, or Inselspital University Hospital in Berne, Switzerland. The control group was composed of individuals from the control population of the Multiple Environmental and Genetic Assessment of Risk Factors for Venous Thrombosis study, which was a large Dutch case-control study performed from March 1, 1999, to September 31, 2004, and in which risk factors for deep vein thrombosis and pulmonary embolism were assessed. Data analysis was performed from January 2 to July 12, 2015. MAIN OUTCOMES AND MEASURES Obesity was determined by body mass index (BMI). A BMI of 30 or greater was considered to indicate obesity, and a BMI of 25 to 29.99 was considered to indicate overweight. A multiple imputation procedure was used for missing data. We adjusted for sex, age, history of cancer, ethnicity, smoking status, and oral contraceptive use. Individuals with normal weight (BMI <25) were the reference category. RESULTS The study included 186 cases and 6134 controls. Cases were younger (median age, 40 vs 48 years), more often female (133 [71.5%] vs 3220 [52.5%]), more often used oral contraceptives (97 [72.9%] vs 758 [23.5%] of women), and more frequently had a history of cancer (17 [9.1%] vs 235 [3.8%]) compared with controls. Obesity (BMI ≥30) was associated with an increased risk of CVT (adjusted odds ratio [OR], 2.63; 95% CI, 1.53-4.54). Stratification by sex revealed a strong association between CVT and obesity in women (adjusted OR, 3.50; 95% CI, 2.00-6.14) but not in men (adjusted OR, 1.16; 95% CI, 0.25-5.30). Further stratification revealed that, in women who used oral contraceptives, overweight and obesity were associated with an increased risk of CVT in a dose-dependent manner (BMI 25.0-29.9: adjusted OR, 11.87; 95% CI, 5.94-23.74; BMI ≥30: adjusted OR, 29.26; 95% CI, 13.47-63.60). No association was found in women who did not use oral contraceptives. CONCLUSIONS AND RELEVANCE Obesity is a strong risk factor for CVT in women who use oral contraceptives

Gene co-expression analysis identifies brain regions and cell types involved in migraine pathophysiology

Migraine is a common disabling neurovascular brain disorder typically characterised by attacks of severe headache and associated with autonomic and neurological symptoms. Migraine is caused by an interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified over a dozen genetic loci associated with migraine. Here, we integrated migraine GWAS data with high-resolution spatial gene expression data of normal adult brains from the Allen Human Brain Atlas to identify specific brain regions and molecular pathways that are possibly involved in migraine pathophysiology. To this end, we used two complementary methods. In GWAS data from 23,285 migraine cases and 95,425 controls, we first studied modules of co-expressed genes that were calculated based on human brain expression data for enrichment of genes that showed association with migraine. Enrichment of a migraine GWAS signal was found for five modules that suggest involvement in migraine pathophysiology of: (i) neurotransmission, protein catabolism and mitochondria in the cortex; (ii) transcription regulation in the cortex and cerebellum; and (iii) oligodendrocytes and mitochondria in subcortical areas. Second, we used the high-confidence genes from the migraine GWAS as a basis to construct local migraine-related co-expression gene networks. Signatures of all brain regions and pathways that were prominent in the first method also surfaced in the second method, thus providing support that these brain regions and pathways are indeed involved in migraine pathophysiology

Reducing the global burden of cerebral venous thrombosis:An international research agenda

Background:Due to the rarity of cerebral venous thrombosis (CVT), performing high-quality scientific research in this field is challenging. Providing answers to unresolved research questions will improve prevention, diagnosis, and treatment, and ultimately translate to a better outcome of patients with CVT. We present an international research agenda, in which the most important research questions in the field of CVT are prioritized.Aims:This research agenda has three distinct goals: (1) to provide inspiration and focus to research on CVT for the coming years, (2) to reinforce international collaboration, and (3) to facilitate the acquisition of research funding.Summary of review:This international research agenda is the result of a research summit organized by the International Cerebral Venous Thrombosis Consortium in Amsterdam, the Netherlands, in June 2023. The summit brought together 45 participants from 15 countries including clinical researchers from various disciplines, patients who previously suffered from CVT, and delegates from industry and non-profit funding organizations. The research agenda is categorized into six pre-specified themes: (1) epidemiology and clinical features, (2) life after CVT, (3) neuroimaging and diagnosis, (4) pathophysiology, (5) medical treatment, and (6) endovascular treatment. For each theme, we present two to four research questions, followed by a brief substantiation per question. The research questions were prioritized by the participants of the summit through consensus discussion.Conclusions:This international research agenda provides an overview of the most burning research questions on CVT. Answering these questions will advance our understanding and management of CVT, which will ultimately lead to improved outcomes for CVT patients worldwide

Brevicoryne brassicae aphids interfere with transcriptome responses of Arabidopsis thaliana to feeding by Plutella xylostella caterpillars in a density‑dependent manner

Plants are commonly attacked by multiple herbivorous species. Yet, little is known about transcriptional patterns underlying plant responses to multiple insect attackers feeding simultaneously. Here, we assessed= transcriptomic responses of Arabidopsis thaliana plants to simultaneous feeding by Plutella xylostella caterpillars and Brevicoryne brassicae aphids in comparison to plants infested by P. xylostella caterpillars alone, using microarray analysis. We particularly investigated how aphid feeding interferes with the transcriptomic response to P. xylostella caterpillars and whether this interference is dependent on aphid density and time since aphid attack. Various JA-responsive genes were up-regulated in response to feeding by P. xylostella caterpillars. The additional presence of aphids, both at low and high densities, clearly affected the transcriptional plant response to caterpillars. Interestingly, some important modulators of plant defense signalling, including WRKY transcription factor genes and ABA-dependent genes, were differentially induced in response to simultaneous aphid feeding at low or high density compared with responses to P. xylostella caterpillars feeding alone. Furthermore, aphids affected the P. xylostella-induced transcriptomic response in a density dependent manner, which caused an acceleration in plant response against dual insect attack at high aphid density compared to dual insect attack at low aphid density. In conclusion, our study provides evidence that aphids influence the caterpillar-induced transcriptional response of A. thaliana in a density-dependent manner. It highlights the importance of addressing insect density to understand how plant responses to single attackers interfere with responses to other attackers and thus underlines the importance of the dynamics of transcriptional plant responses to multiple herbivory

Mapeo de peroxidasas (Prxs) en accesiones de cebada (Hordeum vulgare) mediante la técnica NBS-profiling

2 páginas, 2 figuras -- Póster presentado al Seminario sobre Biodiversidad Vegetal en el Sistema Agroforestal Atlántico, celebrado en Pontevedra (España) entre el 27 y el 28 de octubre de 2010.Las peroxidasas de clase III (Prxs; EC1.11.1.7) se encuentran en todas las plantas superiores. Estas Prxs participan en un amplio rango de procesos fisiológicos debido a su alto número de isoformas y a la regulación tan heterogénea de su expresión. Además, estas enzimas multifuncionales se encuentran altamente conservadas tanto entre genes parálogos como ortólogos. Este trabajo demuestra el uso efectivo de una nueva estrategia, denominada Prx-profiling, para mapear nuevos marcadores homólogos a Prxs en el genoma de cebada (Hordeum vulgare).Gracias al empleo de la nueva estrategia denominada Prx-Profiling, se han conseguido mapear un gran número de genes de Prx en el genoma de cebada, pudiéndose hablar del mapeo de un 95% de los clusters reales de Prxs en cebada.Este trabajo ha sido efectuado gracias a la financiación obtenida por A.M.González por el programa Angeles Alvariño de la Xunta de Galicia y al proyecto Bioexploit Integrated FOOD-CT-2005-513959 que financió a T. Marcel.Peer reviewe