Microtubules as Platforms for Assaying Actin Polymerization In Vivo

The actin cytoskeleton is continuously remodeled through cycles of actin filament assembly and disassembly. Filaments are born through nucleation and shaped into supramolecular structures with various essential functions. These range from contractile and protrusive assemblies in muscle and non-muscle cells to actin filament comets propelling vesicles or pathogens through the cytosol. Although nucleation has been extensively studied using purified proteins in vitro, dissection of the process in cells is complicated by the abundance and molecular complexity of actin filament arrays. We here describe the ectopic nucleation of actin filaments on the surface of microtubules, free of endogenous actin and interfering membrane or lipid. All major mechanisms of actin filament nucleation were recapitulated, including filament assembly induced by Arp2/3 complex, formin and Spir. This novel approach allows systematic dissection of actin nucleation in the cytosol of live cells, its genetic re-engineering as well as screening for new modifiers of the process

Reviewing the use of resilience concepts in forest sciences

Purpose of the review Resilience is a key concept to deal with an uncertain future in forestry. In recent years, it has received increasing attention from both research and practice. However, a common understanding of what resilience means in a forestry context, and how to operationalise it is lacking. Here, we conducted a systematic review of the recent forest science literature on resilience in the forestry context, synthesising how resilience is defined and assessed. Recent findings Based on a detailed review of 255 studies, we analysed how the concepts of engineering resilience, ecological resilience, and social-ecological resilience are used in forest sciences. A clear majority of the studies applied the concept of engineering resilience, quantifying resilience as the recovery time after a disturbance. The two most used indicators for engineering resilience were basal area increment and vegetation cover, whereas ecological resilience studies frequently focus on vegetation cover and tree density. In contrast, important social-ecological resilience indicators used in the literature are socio-economic diversity and stock of natural resources. In the context of global change, we expected an increase in studies adopting the more holistic social-ecological resilience concept, but this was not the observed trend. Summary Our analysis points to the nestedness of these three resilience concepts, suggesting that they are complementary rather than contradictory. It also means that the variety of resilience approaches does not need to be an obstacle for operationalisation of the concept. We provide guidance for choosing the most suitable resilience concept and indicators based on the management, disturbance and application context

Telemedicine and space

Medical procedures during space missions require a high degree of planning in terms of operability of established procedures on earth. Human physiology is different in microgravity. Due to changes in gravitation and radiation, the human body needs to adapt to a different environment. Especially in terms of long-term missions to moon or mars, when immediate contact to earth is not possible, preventive planning is essential. Nevertheless, telemedical support has high importance to ensure best medical care in case of an emergency in space

Establishment of a novel extracorporeal bowel model to study luminal approaches to treat inflammatory bowel disease

SUMMARY We have established an extracorporeal bowel model system for the analysis of early events in inflammatory bowel disease (IBD) and therapeutic applications. This model consists of an intestinal segment that is cannulated and perfused in situ, allowing the investigation of cellular responses of apical mucosa cells on luminal applied substances. Short-term treatment with iodoacetamide mimicked experimental intestinal inflammation in IBD, as indicated by histological alterations such as hemorrhage, hyperemia and loss of regular crypt architecture, as well as enhanced expression of cytokines (e.g. IL-6, IL-10 and MCP-1) compared with control segments perfused with media. Perfusion of therapeutic agents (e.g. dexamethasone or Mutaflor) in the small intestine segment significantly reduced the features of early inflammation that are induced by iodoacetamide. Moreover, similar data were obtained for Resormin®, a montmorillonite-illite mixed-layer mineral (smectite), indicating that smectites might be a newly identified therapeutic option for IBD. In summary, this model could provide novel insights into epithelial injury as well as genesis of IBD and, therefore, be useful in testing the therapeutic potential of compounds for IBD therapy

Evaluation of new methods for airway secure during long-term space missions

Long-term missions with the construction of Lunar Orbital Platform-Gateway and manned Mars missions will be within reach in the upcoming years. An emergency evacuation will not be feasible, thus the crew must handle a lot of possible medical events, presumably without a physician onboard. Including emergencies with a need for airway secure and general anesthesia, recent data shows, that using supraglottic airway is the method of choice in microgravity. If endotracheal intubation is necessary, the usage of videolaryngoscopy is recommended, due to the swelling caused by cardiovascular changes under influence of microgravity. Whenever possible, the patient should be restrained on a stretcher, while securing the airway

On-board emergency medical equipment of European airlines

Background: Medical emergencies frequently occur in commercial airline flights, but valid data on causes and consequences are rare. Therefore, optimal extent of onboard emergency medical equipment remains largely unknown. Whereas a minimum standard is defined in regulations, additional material is not standardized and may vary significantly between airlines. Methods: European airlines operating aircrafts with at least 30 seats were selected and interviewed with a 5-page written questionnaire including 81 items. Besides pre-packed and required emergency medical material, drugs, medical devices, and equipment lists were queried. If no reply was received, airlines were contacted up to three times by email and/or phone. Descriptive analysis was used for data interpretation. Results: From a total of 305 European airlines, 253 were excluded from analysis (e.g., no passenger transport). 52 airlines were contacted and data of 22 airlines were available for analysis (one airline was excluded due to insufficient data). A first aid kit is available on all airlines. 82% of airlines (18/22) reported to have a doctor's kit (DK) or an Emergency Medical Kit (EMK) onboard. 86% of airlines (19/22) provide identical equipment in all aircraft of the fleet, and 65% (14/22) airlines provide an automated external defibrillator. Conclusions: Whereas minimal required material according to European aviation regulations is provided by all airlines for medical emergencies, there are significant differences in availability of the additional material. The equipment of most airlines is not sufficient for treatment of specific emergencies according to published in-flight medical guidelines (e.g., for CPR or acute myocardial infarction)

Airway management in microgravity: A systematic review

Introduction In the near future, space programs will shift their focus toward long-duration interplanetary missions, in particular to the Moon and Mars. These exploration missions will be associated with an increased risk of acute medical problems, which will need to be handled by an autonomous crew operating in extreme isolation. An important skill in emergencies is represented by airway management. Many airway devices are available and it is unclear which one would be the most suitable in the context of a space mission. The aim of this systematic review was to analyze the existing literature on airway management in the special situation of weightlessness during space missions. Material and methods We performed a standardized review of published literature on airway management in spaceflight and analogue environments using the database PubMed. Results We identified a total of 3111 publications of which 3039 were initially excluded after evaluation. The screening identified three randomized comparative manikin studies, two of them in parabolic flights, one in a submerged setup. Under free-floating conditions, the insertion success rate of supraglottic airway devices (SGA) was excellent (91%-97%). The administration of artificial ventilation could be successfully achieved in weightlessness with SGA. The success rate of conventional laryngoscopy under free-floating conditions fluctuated between 15% and 86%. Conclusion It appears possible to safely manage the airway in weightlessness, provided that certain conditions are ensured, such as restraining the patient and operator for conventional orotracheal intubation. If airway protection is required with endotracheal intubation, both the operator and the patient should be restrained

Airway management in weightlessness

The aim of this review is to analyze the existing literature on airway management in the special situation of weightlessness during space missions. A narrative review of published literature on airway management in spaceflight and analogue environments using the database PubMed was conducted. Screening of literature identified 3 randomized comparative manikin studies, 2 of them in parabolic flights, 1 in a submerged setup. Under free-floating conditions, the insertion success rate of supraglottic airway devices (SGA) was excellent (91-97 %). The administration of artificial ventilation could be successfully achieved in weightlessness with SGA. The success rate of conventional laryngoscopy under free-floating conditions fluctuated between 15-86 %. It appears possible to safely manage the airway in weightlessness, provided that certain conditions are ensured, such as restraining the patient and operator for conventional orotracheal intubation. If airway protection is required with endotracheal intubation, both the operator and the patient should be restrained