Real-time MR imaging of myocardial regional function using strain-encoding (SENC) with tissue through-plane motion tracking.

PURPOSE: To implement real-time myocardial strain-encoding (SENC) imaging in combination with tracking the tissue displacement in the through-plane direction. MATERIALS AND METHODS: SENC imaging was combined with the slice-following technique by implementing three-dimensional (3D) selective excitation. Certain adjustments were implemented to reduce scan time to one heartbeat. A total of 10 volunteers and five pigs were scanned on a 3T MRI scanner. Spatial modulation of magnetization (SPAMM)-tagged images were acquired on planes orthogonal to the SENC planes for comparison. Myocardial infarction (MI) was induced in two pigs and the resulting SENC images were compared to standard delayed-enhancement (DE) images. RESULTS: The strain values computed from SENC imaging with slice-following showed significant difference from those acquired without slice-following, especially during systole (P < 0.01). The strain curves computed from the SENC images with and without slice-following were similar to those computed from the orthogonal SPAMM images, with and without, respectively, tracking the tag line displacement in the strain direction. The resulting SENC images showed good agreement with the DE images in identifying MI in infarcted pigs. CONCLUSION: Correction of through-plane motion in real-time cardiac functional imaging is feasible using slice-following. The strain measurements are more accurate than conventional SENC measurements in humans and animals, as validated with conventional MRI tagging.

Micromeasurement of total and regional CO2 productions in the one-day-old chick embryo.

A conductometric micromethod combined with image analysis system has been developed allowing to determine the CO2 production within 'two-dimensional' tissues, i.e., flat and thin cell layers or epithelial sheets. The preparation was mounted into an airtight chamber separated in two compartments by a thin silicone membrane permeable to gases. The lower compartment contained the nutritive medium and the preparation. The upper compartment and a conductivity measuring capillary connected in series were perfused with a solution of Ba(OH)2. The CO2 produced by the tissue precipitated as BaCO3 and the resulting decrease of electrical conductivity was linearly related to the total CO2 production. In addition, the pattern of CO2 production was directly observable as the BaCO3 crystals formed upon the silicone membrane over the regions which produced CO2. The spatial distribution of the crystals was quantified by video image processing and the regional CO2 production evaluated with a spatial resolution of 100 microns. This new microtechnique was originally developed to study the CO2 production in the early chick blastoderm which is a disc 1-5 cells thick. At the stage of young neurula the CO2 production was found to be 235 +/- 37 nmol.h-1 (mean +/- SD; n = 10) per blastoderm and large variations of local CO2 production were detected from one region to another (from 0.6 to 6.5 nmol.h-1.mm-2). These results indicate a high metabolic and functional differentiation of cells within the blastoderm. The possible applications and improvements of such a microtechnique are discussed.

A functional microsatellite of the macrophage migration inhibitory factor gene associated with meningococcal disease.

Macrophage migration inhibitory factor (MIF) is an abundantly expressed proinflammatory cytokine playing a critical role in innate immunity and sepsis and other inflammatory diseases. We examined whether functional MIF gene polymorphisms (-794 CATT(5-8) microsatellite and -173 G/C SNP) were associated with the occurrence and outcome of meningococcal disease in children. The CATT(5) allele was associated with the probability of death predicted by the Pediatric Index of Mortality 2 (P=0.001), which increased in correlation with the CATT(5) copy number (P=0.04). The CATT(5) allele, but not the -173 G/C alleles, was also associated with the actual mortality from meningoccal sepsis [OR 2.72 (1.2-6.4), P=0.02]. A family-based association test (i.e., transmission disequilibrium test) performed in 240 trios with 1 afflicted offspring indicated that CATT(5) was a protective allele (P=0.02) for the occurrence of meningococcal disease. At baseline and after stimulation with Neisseria meningitidis in THP-1 monocytic cells or in a whole-blood assay, CATT(5) was found to be a low-expression MIF allele (P=0.005 and P=0.04 for transcriptional activity; P=0.09 and P=0.09 for MIF production). Taken together, these data suggest that polymorphisms of the MIF gene affecting MIF expression are associated with the occurrence, severity, and outcome of meningococcal disease in children.

Medial migration of lag screw after gamma nailing.

Fractures of the proximal femur are common in the elderly population. Intramedullary nailing has become the standard treatment for intertrochanteric fractures although several extramedullary implants (e.g. dynamic hip screw (DHS), blade plate, locking compression plate (LCP), etc.) exist. However, despite this being a very common operation in traumatology, there are numerous associated complications. We report the rare complication of the migration of the medial lag screw into the pelvis at five and a half weeks postoperatively. The implant was removed and replaced by a total hip arthroplasty with simultaneous grafting of the acetabular defect and strapping of the greater trochanter. The evolution was favourable. We also present a review of the literature and analyze our case.

Simultaneous measurement of regional cerebral blood flow by perfusion CT and stable xenon CT: a validation study.

BACKGROUND AND PURPOSE: Knowledge of cerebral blood flow (CBF) alterations in cases of acute stroke could be valuable in the early management of these cases. Among imaging techniques affording evaluation of cerebral perfusion, perfusion CT studies involve sequential acquisition of cerebral CT sections obtained in an axial mode during the IV administration of iodinated contrast material. They are thus very easy to perform in emergency settings. Perfusion CT values of CBF have proved to be accurate in animals, and perfusion CT affords plausible values in humans. The purpose of this study was to validate perfusion CT studies of CBF by comparison with the results provided by stable xenon CT, which have been reported to be accurate, and to evaluate acquisition and processing modalities of CT data, notably the possible deconvolution methods and the selection of the reference artery. METHODS: Twelve stable xenon CT and perfusion CT cerebral examinations were performed within an interval of a few minutes in patients with various cerebrovascular diseases. CBF maps were obtained from perfusion CT data by deconvolution using singular value decomposition and least mean square methods. The CBF were compared with the stable xenon CT results in multiple regions of interest through linear regression analysis and bilateral t tests for matched variables. RESULTS: Linear regression analysis showed good correlation between perfusion CT and stable xenon CT CBF values (singular value decomposition method: R(2) = 0.79, slope = 0.87; least mean square method: R(2) = 0.67, slope = 0.83). Bilateral t tests for matched variables did not identify a significant difference between the two imaging methods (P >.1). Both deconvolution methods were equivalent (P >.1). The choice of the reference artery is a major concern and has a strong influence on the final perfusion CT CBF map. CONCLUSION: Perfusion CT studies of CBF achieved with adequate acquisition parameters and processing lead to accurate and reliable results.

Agents de migration : les intermédiaires sur le marché suisse des footballeurs et danseuses de cabaret

En se focalisant sur le cas des joueurs de football professionnels et des danseuses de cabaret, cet article met en lumière le rôle joué par différents types d'intermédiaire dans la mise en place, le développement et la gestion de canaux migratoires. Une attention particulière est accordée aux procédures recrutement et à la gestion de la circulation de ces deux catégories de travailleurs.

A model for organ donation in switzerland, the latin organ donation programme (lodp); an ongoing successful regional initiative

Background: The 1st Swiss federal Transplant Law was finally enforced in July 2007 with the obligation to promote quality and efficiency in transplant procedures. The LODP was created to develop organ and tissue donation in the Latin area of Switzerland covering seventeen hospitals (29% of the population).Methods: Each of the partner hospitals designated at least one Local Donor Coordinator (LDC), member of the Intensive Care team, trained in the organ donation (OD) process. The principal tasks of the LDC's are the introduction of OD procedures, organisation of educational sessions for hospital staff and execution of the Donor Action programme. The LODP has been operational since July 2009, when training of the LDC's was completed, the web-site and hotline activated and the attendance of Transplant Procurement Coordinators (TPC) during the OD process organised.Results: National and regional guidelines are accessible on the LODP website. The Hospital Attitude Survey obtained a 57% return rate. Many of the staff requested training and sessions are now running in the partner hospitals. The Medical Record Revue revealed an increase in the conversion rate from 3.5% to 4.5%. During the 5 years before creation of LODP the average annual number of utilised donors was 31, an increase of 70%, has since been observed.Conclusion: This clear progression in utilised donors in the past two years can be attributed to the fact that partner hospitals benefit from the various support given (hotline, website and from TPC's). Despite the increase in OD within the LODP the Swiss donation rates remain low, on average 11.9 donors per million population. This successful model should be applied throughout Switzerland, but the crucial point is to obtain financial support.

Problèmes dus aux fistules d'hémodialyse: un réseau régional de prise en charge [Problems related to haemodialysis vascular accesses: a regional network of care]

The number of patients treated by haemodialysis (HD) is continuously increasing. The complications associated with vascular accesses represent the first cause of hospitalisation in these patients. Since 2001 nephrologists, surgeons, angiologists and radiologists at the CHUV are working to develop a multidisciplinary model that includes planning and monitoring of HD accesses. In this setting the echo-Doppler represents an important tool of investigation. Every patient is discussed and decisions are taken during a weekly multidisciplinary meeting. A network has been created with nephrologists of peripheral centres and other specialists. This model allows to centralize investigational information and coordinate patient care while keeping and even developing some investigational activities and treatment in peripheral centres.