‚Intensive care unit-acquired weakness‘ und neuromuskulärer Ultraschall

Die Anaesthesiologie -     

Impact of Food Intake on Liver Stiffness Determined by 2-D Shear Wave Elastography: Prospective Interventional Study in 100 Healthy Patients

The aim was to evaluate the influence of food intake on liver stiffness measurement (LSM), performed with 2-D shear wave elastography (Logiq E9, GE Medical Systems, Wauwatosa, WI, USA). One hundred healthy volunteers were prospectively enrolled. Mean age was 25.8 (19–55) y, and mean body mass index was 22.43 (17.3–30.8) kg/m². Patients fasted for at least 3 h and subsequently ingested a liquid meal of 800 kcal. Liver stiffness and portal vein velocity were measured before and after food intake. Food intake resulted in significantly higher LSM values compared with baseline LSM (5.74 ± 0.94 kPa vs. 4.80 ± 0.94 kPa, p < 0.001). On multiple linear regression analysis, body mass index was significantly positively correlated with the LSM increase after food intake (p?=?0.01). No correlation between the increase in LSM and the increase in post-prandial portal vein velocity was observed (r?=?0.09). In summary, food intake has a significant influence on LSM. There is an 11% risk of misclassifying non-fasting, healthy patients as having significant fibrosis.     

Augenbefall und Systemerkrankung – periokuläre und intraokuläre Lymphome

Die Onkologie - Das okuläre Lymphom wird anhand seiner anatomischen Lokalisation in die intraokulären und periokulären Lymphome eingeteilt. Intraokulär kann die Uvea mit ihren...     

Compensatory mechanisms affect sensorimotor integration during ongoing vocal motor acts in marmoset monkeys

Any transmission of vocal signals faces the challenge of acoustic interferences such as heavy rain, wind, animal or urban sounds. Consequently, several mechanisms and strategies have evolved to optimize signal‐to‐noise ratio. Examples to increase detectability are the Lombard effect, an involuntary rise in call amplitude in response to masking ambient noise, which is often associated with other vocal changes such as call frequency and duration, as well as the animals’ capability of limiting calling to periods where noise perturbation is absent. Previous studies revealed vocal flexibility and various audio‐vocal integration mechanisms in marmoset monkeys. Using acoustic perturbation triggered by vocal behaviour, we investigated whether marmosets are capable of exhibiting changes in call structure when perturbing noise starts after call onset or whether such effects only occur if noise perturbation starts prior to call onset. We show that marmosets are capable of rapidly modulating call amplitude and frequency in response to such noise perturbation. Vocalizations swiftly increased call frequency after noise onset indicating a rapid effect of perturbing noise on vocal motor production. Call amplitudes were also affected. Interestingly, however, the marmosets did not exhibit the Lombard effect as previously reported but decreased call intensity in response to noise. Our findings indicate that marmosets possess a general avoidance strategy to call in the presence of ambient noise and suggest that these animals are capable of counteracting a previously thought involuntary audio‐vocal mechanism, the Lombard effect. These findings will pave the way to investigate the underlying audio‐vocal integration mechanisms explaining these behaviours.     

Low-dose hydrocortisone in patients with COVID-19 and severe hypoxia (COVID STEROID) trial—Protocol and statistical analysis plan

Introduction

Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.

Methods

The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.

Discussion

The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.

     

Trypanosoma cruzi Calreticulin Topographical Variations in Parasites Infecting Murine Macrophages

Trypanosoma cruzi calreticulin (TcCRT), a 47-kDa chaperone, translocates from the endoplasmic reticulum to the area of flagellum emergence. There, it binds to complement components C1 and mannan-binding lectin (MBL), thus acting as a main virulence factor, and inhibits the classical and lectin pathways. The localization and functions of TcCRT, once the parasite is inside the host cell, are unknown. In parasites infecting murine macrophages, polyclonal anti-TcCRT antibodies detected TcCRT mainly in the parasite nucleus and kinetoplast. However, with a monoclonal antibody (E2G7), the resolution and specificity of the label markedly improved, and TcCRT was detected mainly in the parasite kinetoplast. Gold particles, bound to the respective antibodies, were used as probes in electron microscopy. This organelle may represent a stopover and accumulation site for TcCRT, previous its translocation to the area of flagellum emergence. Finally, early during T. cruzi infection and by unknown mechanisms, an important decrease in the number of MHC-I positive host cells was observed.     

Visual pathways in the brain of the jumping spider Marpissa muscosa

Some animals have evolved task differentiation among their eyes. A particular example is spiders, where most species have eight eyes, of which two (the principal eyes) are used for object discrimination, whereas the other three pairs (secondary eyes) detect movement. In the ctenid spider Cupiennius salei, these two eye types correspond to two visual pathways in the brain. Each eye is associated with its own first- and second-order visual neuropil. The second-order neuropils of the principal eyes are connected to the arcuate body, whereas the second-order neuropils of the secondary eyes are linked to the mushroom body. We explored the principal- and secondary eye visual pathways of the jumping spider Marpissa muscosa, in which size and visual fields of the two eye types are considerably different. We found that the connectivity of the principal eye pathway is the same as in C. salei, while there are differences in the secondary eye pathways. In M. muscosa, all secondary eyes are connected to their own first-order visual neuropils. The first-order visual neuropils of the anterior lateral and posterior lateral eyes are connected with a second-order visual neuropil each and an additional shared one (L2). In the posterior median eyes, the axons of their first-order visual neuropils project directly to the arcuate body, suggesting that the posterior median eyes do not detect movement. The L2 might function as an upstream integration center enabling faster movement decisions.     

Optimized dualCEST‐MRI for imaging of endogenous bulk mobile proteins in the human brain

Dual‐frequency irradiation chemical exchange saturation transfer (dualCEST) allows imaging of endogenous bulk mobile proteins by selectively measuring the intramolecular spin diffusion. The resulting specificity to changes in the concentration, molecular size, and folding state of mobile proteins is of particular interest as a marker for neurodegenerative diseases and cancer. Until now, application of dualCEST in clinical trials was prevented by the inherently small signal‐to‐noise ratio and the resulting comparatively long examination time. In this study, we present an optimized acquisition protocol allowing 3D dualCEST‐MRI examinations in a clinically relevant time frame. The optimization comprised the extension of the image readout to 3D, allowing a retrospective co‐registration and application of denoising strategies. In addition, cosine‐modulated dual‐frequency presaturation pulses were implemented with a weighted acquisition scheme of the necessary frequency offsets. The optimization resulted in a signal‐to‐noise ratio gain by a factor of approximately 8. In particular, the application of denoising and the motion correction were the most crucial improvement steps. In vitro experiments verified the preservation of specificity of the dualCEST signal to proteins. Good‐to‐excellent intra‐session and good inter‐session repeatability was achieved, allowing reliable detection of relative signal differences of about 16% or higher. Applicability in a clinical setting was demonstrated by examining a patient with glioblastoma. The optimized acquisition protocol for dualCEST‐MRI at 3 T enables selective imaging of endogenous bulk mobile proteins under clinically relevant conditions.