Perception of longitudinal body axis in microgravity during parabolic flight

It has been proposed that an internal representation of body vertical has a prominent role in spatial orientation. This investigation investigated the ability of human subjects to accurately locate their longitudinal body axis (an imaginary straight body midline running from head to toes) while free-floating in microgravity. Subjects were tested in-flight, as well as on ground in normal gravity in both the upright and supine orientations to provide baseline measurements. The subjects wore a goggle device and were in total darkness. They used knobs to rotate two luminous lines until they were parallel to the subjective direction of their longitudinal body axis, in the roll (right/left) and the pitch (forward/backward) planes. Results showed that the error between the perceived and the objective direction of the longitudinal body axis was significantly larger in microgravity than in normal gravity. This error in this egocentric frame of reference is presumably due to the absence of somatosensory cues when free-floating. Mechanical pressure on the chest using an airbag reduced the error in perception of the longitudinal body axis in microgravity, thus improving spatial orientation.     

In-vivo evaluation of convex array synthetic aperture imaging

This paper presents an in-vivo study of synthetic transmit aperture (STA) imaging in comparison with conventional imaging, evaluating whether STA imaging is feasible in-vivo and whether the image quality obtained is comparable with traditional scanned imaging in terms of penetration depth, spatial resolution, contrast resolution and artifacts. Acquisition was performed using our research scanner RASMUS and a 5.5 MHz convex array transducer. STA imaging was acquired using circular wave emulation by 33-element subapertures and a 20 micros linear FM signal as excitation pulse. For conventional imaging, a 64 element aperture was used in transmit and receive with a 1.5 cycle sinusoid excitation pulse. Conventional and STA images were acquired interleaved, ensuring that the exact same anatomical location was scanned. Image sequences were recorded in real time and processed off-line. Seven male volunteers were scanned abdominally and the resulting images were compared by three medical doctors using randomized blinded presentation. Penetration and image quality were scored and evaluated statistically. Results showed slightly but significantly (0.48 cm, p = 0.008) increased penetration using STA. Image quality was also highly significantly (p < 0.001) increased. Results show that in-vivo ultrasound imaging using STA is feasible for abdominal imaging without severe motion artifacts.     

Intravenous immunoglobulin significantly reduces exposure of concomitantly administered anti‐C5 monoclonal antibody tesidolumab

Awareness of drug‐drug interactions is critical in organ transplant recipient management. However, biologic agents interfering with monoclonal antibodies is not widely considered. We report the effect of high‐dose intravenous immunoglobulin (IVIg) on safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of the human anti‐C5 monoclonal antibody tesidolumab (LFG316) in end‐stage renal disease patients awaiting kidney transplant. In this single‐center, phase 1, open‐label, parallel‐group study, 8 patients were assigned to receive either single‐dose tesidolumab + IVIg or tesidolumab alone, with 56‐day follow‐up. Within‐group PK parameters were consistent. Mean tesidolumab exposure decreased 34%, clearance increased 63%, and half‐life decreased 41% comparing tesidolumab + IVIg to tesidolumab alone. IVIg influence on tesidolumab elimination was most evident in the first 3 weeks. Complete suppression of both total and alternative complement activities was maintained for 4 weeks in the tesidolumab alone group and for 2 weeks in the tesidolumab + IVIg group. Tesidolumab was well tolerated. IVIg infused before tesidolumab affected tesidolumab PK and PD, resulting in a shortened period of full complement activity inhibition. These findings suggest a clinically relevant impact of IVIg on monoclonal antibody clearance and indirectly hint at an IVIg mechanism of action in treating autoimmune diseases and allosensitization by accelerating pathogenic IgG antibody degradation. Trial registration number: NCT02878616.     

The Effect of Type of Femoral Component Fixation on Mortality and Morbidity after Hip Hemiarthroplasty: A Systematic Review and Meta-Analysis

HSS Journal ® - Hip hemiarthroplasty is a well-established treatment of displaced femoral neck fracture, although debate exists over whether cemented or uncemented fixation is superior....     

Operative versus nonoperative treatment of displaced midshaft clavicle fractures in adults: a systematic review

Objectives

Intervention studies of clavicle fracture treatment are numerous, but only a few high quality studies prospectively compare operative and nonoperative treatment. The objective of this study was to review evidence from randomized controlled trials on operative versus nonoperative treatment of displaced midshaft clavicle fractures in adults with focus on fracture healing, complications and functional outcome.

Data sources

An electronic search was performed of PubMed, Embase and Cochrane databases which revealed 559 articles. All articles published before October 18th 2012 and written in English, Danish or Swedish were eligible.

Study selection

Articles were excluded if they included children under the age of 16, did not include acute midshaft fractures, included concomitant fractures, did not meet the requirements of Level I evidence according to Centre for evidence based medicine 2009 guidelines, were systematic reviews or meta-analyses, or did not compare operative and nonoperative treatment.

Data extraction

Articles were parsed for relevance by two reviewers independently regarding title, abstract, and full text. Extraction of data was done by both reviewers in collaboration and sorted according to the aims of the study. Complications were grouped according to additional surgery required. The quality of studies was assessed by both reviewers in unison using Critical Appraisal Skills Programme 2010 checklists.

Conclusions

It seems like operative intervention leads to fewer nonunions at the cost of an increase in minor complications compared to nonoperative treatment. However, the effects of operation on functional outcome remains controversial. High quality evidence is currently sparse supporting either operative or nonoperative treatment on displaced midshaft clavicle fractures in adults.