Body-worn sensor design: what do patients and clinicians want?

User preferences need to be taken into account in order to be able to design devices that will gain acceptance both in a clinical and home setting. Sensor systems become redundant if patients or clinicians do not want to work with them. The aim of this systematic review was to determine both patients' and clinicians' preferences for non-invasive body-worn sensor systems. A search for relevant articles and conference proceedings was performed using MEDLINE, EMBASE, Current Contents Connect, and EEEI explore. In total 843 papers were identified of which only 11 studies were deemed suitable for inclusion. A range of different clinically relevant user groups were included. The key user preferences were that a body-worn sensor system should be compact, embedded and simple to operate and maintain. It also should not affect daily behavior nor seek to directly replace a health care professional. It became apparent that despite the importance of user preferences, they are rarely considered and as such there is a lack of high-quality studies in this area. We therefore would like to encourage researchers to focus on the implications of user preferences when designing wearable sensor systems.

A novel method for determining ground-referenced contacts during stair ascent: comparing relative hip position to quiet standing hip height.

Stair climbing can be measured using body-fixed sensors, whereby the origin and axes of the coordinate system are fixed with respect to the geometry of a body segment. These sensors can be part of a portable system, which provides the possibility to collect data in complex real-life environments. However due to the fact that the sensors are body-fixed, difficulties in determining the ground-based parameters of stair ascent can occur. The purpose of this study is to present a new approach for determining initial contacts based on a multi-chain biomechanical model combined with a new analysis method, in which relative hip height is compared to hip height during normal standing. Initial contacts obtained from the proposed method were compared to those obtained using an optical tracking device. An average absolute timing difference ranging from 0.04 (SD + or - 0.03) to 0.06 (+ or - 0.03) s and a root mean square error ranging from 0.05 to 0.07 s were found between the two techniques. This shows that the new approach presented in this study can be used to accurately determine initial contacts during stair ascent using portable equipment.

Translation elongation factor eEF1A2 is essential for post-weaning survival in mice.

Translation elongation factor eEF1A, formerly known as EF-1 alpha, exists as two variant forms; eEF1A1, which is almost ubiquitously expressed, and eEF1A2, whose expression is restricted to muscle and brain at the level of whole tissues. Expression analysis of these genes has been complicated by a general lack of availability of antibodies that specifically recognize each variant form. Wasted mice (wst/wst) have a 15.8-kilobase deletion that abolishes activity of eEF1A2, but before this study it was unknown whether the deletion also affected neighboring genes. We have generated a panel of anti-peptide antibodies and used them to show that eEF1A2 is expressed at high levels in specific cell types in tissues previously thought not to express this variant, such as pancreatic islet cells and enteroendocrine cells in colon crypts. Expression of eEF1A1 and eEF1A2 is shown to be generally mutually exclusive, and we relate the expression pattern of eEF1A2 to the phenotype seen in wasted mice. We then carried out a series of transgenic experiments to establish whether the expression of other genes is affected by the deletion in wasted mice. We show that aspects of the phenotype such as motor neuron degeneration relate precisely to the relative expression of eEF1A1 and eEF1A2, whereas the immune system abnormalities are likely to result from a stress response. We conclude that loss of eEF1A2 function is solely responsible for the abnormalities seen in these mice.

Expression of eEF1A2 is associated with clear cell histology in ovarian carcinomas: overexpression of the gene is not dependent on modifications at the EEF1A2 locus.

The tissue-specific translation elongation factor eEF1A2 is a potential oncogene that is overexpressed in human ovarian cancer. eEF1A2 is highly similar (98%) to the near-ubiquitously expressed eEF1A1 (formerly known as EF1-alpha) making analysis with commercial antibodies difficult. We wanted to establish the expression pattern of eEF1A2 in ovarian cancer of defined histological subtypes at both the RNA and protein level, and to establish the mechanism for the overexpression of eEF1A2 in tumours. We show that while overexpression of eEF1A2 is seen at both the RNA and protein level in up to 75% of clear cell carcinomas, it occurs at a lower frequency in other histological subtypes. The copy number at the EEF1A2 locus does not correlate with expression level of the gene, no functional mutations were found, and the gene is unmethylated in both normal and tumour DNA, showing that overexpression is not dependent on genetic or epigenetic modifications at the EEF1A2 locus. We suggest that the cause of overexpression of eEF1A2 may be the inappropriate expression of a trans-acting factor. The oncogenicity of eEF1A2 may be related either to its role in protein synthesis or to potential non-canonical functions.

[Endovascular embolization in gastrointestinal hemorrhage]. / Endovasculaire embolisatie bij gastro-intestinale bloedingen.

The indications, the technique and the choice of materials for transcatheter embolisation in three patients are described. A 73-year-old woman with Henoch-Schönlein vasculitis was admitted with haematemesis and melaena. Angiography showed active haemorrhage in a branch of the pancreaticoduodenal artery. The common hepatic artery was catheterised up to the pancreaticoduodenal artery and superselective transcatheter embolisation was accomplished using polyvinyl alcohol (PVA) particles of 0.3-0.5 mm diameter. A 82-year-old woman with chronic cardiac decompensation developed serious haematemesis after a papillotomy. With the help of PVA particles the bleeding A. pancreaticoduodenalis inferior ramus posterior was embolised. Several days after a pancreaticoduodenectomy for a carcinoma of the papilla of Vater a 75-year-old man went into shock. The angiogram revealed haemorrhage of the right hepatic artery. With the combination of microcoils and a coaxial balloon catheter proximal of the bifurcation of the hepatic artery haemorrhage could be arrested. Haemorrhage did not recur and all patients could be discharged in good condition. When local anatomy has been changed by earlier surgery or when patients in bad general condition are concerned, transcatheter embolisation can offer the solution in active haemorrhage.