Biotin supply by large bowel bacteria in minipigs: Evidence from intracaecal avidin

The influence of a change of colonic availability of biotin on biotin status was studied. This was done by inhibition of biotin absorption by intracaecal avidin infusion. Five adult minipigs with a permanent caecal ‘T' cannula were fed on a semi-synthetic, biotin-deficient diet for 4 months. Following an 8-week adaptation period there were nine sequential 1-week infusion periods with or without oral lactulose or antibiotics. Avidin infusion during weeks 2, 5 and 8 amounted to 18 mg/d (13 U/mg). Plasma biotin concentrations were not changed by avidin infusions. There was a significant average 84% rise in faecal biotin excretion during the avidin periods. Urinary biotin output following avidin decreased by 21 %. This is taken as evidence that biotin synthesized by colonic bacteria is available for host metabolism. A rough estimate shows that under basal conditions 1.7-17% of the metabolic allowance may be covered by this metabolic rout

Health professions students' interprofessional experiences on a rural learning platform

HEALTH PROFESSIONS STUDENTS’ LEARNING EXPERIENCES ON A RURAL COLLABORATIVE LEARNING PLATFORM ABSTRACTA Faculty of Health Sciences launched a rural collaborative learning platform to cultivate interprofessional key competencies and to improve health outcomes. The purpose of the study was to describe health sciences students’ experiences of an rural collaborative learning platform. Health professions students created digital stories reflecting on their collaborative learning experiences. Purposive sampling resulted in 23 submissions. Qualitative analysis of content identified themes and categories. Three themes, namely, metaphor, critical consciousness and professional socialisation, were identified. The metaphor categories, Journey, Setting world ablaze, Water, and Puzzle, represent students’ desire to use visual cues to describe their experiences. Transformation, Personal development and Empathy signified critical consciousness. Collaborative practice, Values, Reflective practice, and Key competencies relate to professional socialisation. The researchers gained understanding of students’ experiences on an rural collaborative learning platform. Through digital stories, students became aware of professional interdependency, which linked their experiences to key interprofessional competencies.

Ability of eight multi-joint models to compensate for soft tissue artefacts using global optimisation - An in vivo study of knee kinematics during squats

International Symposium on 3D Analysis of Human Movement (3D-AHM), LAUSANNE, SUISSE, 14-/07/2014 - 17/07/2014Soft tissue artefacts (STA) distort marker-based knee kinematics. Global optimization (GO) compensates for STA, but it lacks of direct validation on subjects. This study evaluates the performance of eight multi-joint models used in GO. Ten subjects were recruited: five healthy and five osteoarthritis subjects. Each subject performed dynamic squats recorded with a motion capture system (KneeKG?), and a quasi-static squat recorded with a low-dose upright biplanar radiographic imaging system (EOS®). The eight multi-joint models were evaluated by comparing dynamic knee kinematics optimized with GO to quasi-static knee kinematics measured by EOS®. The mean RMSE values ranged from 1.5-11.4° for rotations and 1.4-6.2 mm for translations. Some models were able to compensate for STA along one axe of movement but not along another. None of these models seemed optimal for STA compensation along all axes of movement. Future studies should investigate new models based on subject-specific joint geometry

BIOMECHANICAL STUDY ON CADAVER KNEE FOR THE EVALUATION OF CRUCIATE KNEE LIGAMENT RECONSTRUCTIONS

INTRODUCTION: Ruptures of the anterior and posterior cruciate knee ligament (ACL and PCL), alone or combined, are some of the most frequent joint injuries, especially in sports. The long-term unsatisfactory results and lack of systematic evaluation of surgical reconstructions have led us to undergo an evaluation on cadaver knees. MATERIAL AND METHOD: A preliminary study was performed on one cadaver knee. The femur was fixed on a holder and magnetic sensors “BirdsTM” were attached to the tibia and the femur, which tracked the knee’s movement. A threedimensional knee analyzer GENI(1) was used to calculate kinematic parameters (tibial internal and external rotation and ab/adduction), as well as ligament combined deformation (elongation / bending / torsion) during knee flexion. This experiment was performed on an intact knee and a knee where the PCL has been cut and reconstructed using a synthetic Trevia ligament. Finally the knee was dissected to produce a combined postero-lateral instability and reconstructed with and without postero-lateral corner reconstruction. The effect of different reconstruction methods on kinematics and ligament deformation were compared. RESULTS AND DISCUSSION: Kinematic parameters changed significantly when PCl and postero-lateral corner were dissected. The reconstruction of the PCL alone, using an “Over-the-Bottom” method described by Krudwig(2), shifted the curves back to the initial situation and decreased the variability of the movement. Ligament deformation was 3 mm elongation, 50o femoral flexion and 90o torsion. These values are in accordance with material properties and should lead to good long-term biofunctionnality. CONCLUSION: This study proposes an in vitro protocol for a better understanding of the clinical success or failure of different procedures. Preliminary results showed that the system and the protocol setup are sensitive to changes in kinematics following posterior cruciate ligament dissection and reconstruction. Experiments are performed at this time on several cadaver knees, in order to compare different reconstruction methods. REFERENCES: Sati, M. et al. (1997). Computer Assisted Knee Surgery: Diagnostics and Planning of Knee Surgery. Computer Aided Surgery 2, 108-123. Krudwig, W. (1997). In L'H. Yahia (Ed.), Ligaments and Ligamentoplasties. Heidelberg: Springer Verlag

Inefficacy of different strategies to improve guideline awareness – 5-year follow-up of the hypertension evaluation project (HEP)

<p>Abstract</p> <p>Background</p> <p>In spite of numerous guidelines for evidence based diagnostic and therapy adequate knowledge of current recommendations is disappointingly low. In the Hypertension Evaluation Project (HEP I) we showed that awareness of national hypertension guidelines under German practitioners was less than 25% in the year 2000. This indicates the need for efficient strategies to relevantly improve guideline awareness.</p> <p>Methods</p> <p>To asses different tools for amending guideline knowledge we used three strategies (guideline in print, interactive guideline, expert seminars) to train 8325 randomised physicians, who had participated in the HEP I trial. Guideline knowledge of the trained physicians was again tested with the HEP questionnaire and compared to a control group of HEP I physicians.</p> <p>Results</p> <p>The return rate of questionnaires was 57.9% without a significant distinction between the groups. Overall guideline awareness was still low but remarkably improved compared to the results of HEP I (37.1% vs. 23.7%, p < 0.0001). There was no difference between the trained physicians and the control group (35.8% and 35.9% vs. 39.7%, p = n.s.).</p> <p>Conclusion</p> <p>We investigated the influence of different strategies to improve guideline awareness among German physicians. None of our interventions (guideline in print, interactive guideline, expert seminars) brought a notable benefit compared to control group. However, overall knowledge of guideline contents increased from 23.7% to 37.1% over five years. Therefore, other probably multimodal interventions are necessary to significantly improve guideline awareness beyond spontaneous advancement.</p> <p>Trial Registration</p> <p>ISRCTN53383289</p

Compliance of a cobalt chromium coronary stent alloy – the COVIS trial

BACKGROUND: Cobalt chromium coronary stents are increasingly being used in percutaneous coronary interventions. There are, however, no reliable data about the characteristics of unfolding and visibility of this stent alloy in vivo. The aim of this study is to compare cobalt chromium coronary stents with conventional stainless steel stents using intracoronary ultrasound. METHODS: Twenty de novo native coronary stenoses ≤ 20 mm in length (target vessel reference diameter ≥ 2.5 and ≤ 4.0 mm) received under sequential intracoronary ultrasound either a cobalt chromium stent (Multi-Link Vision(®); n = 10) or a stainless steel stent (Multi-Link Zeta(®); n = 10). RESULTS: For optimal unfolding, the cobalt chromium stent requires a higher balloon deployment pressure (13.90 ± 2.03 atm) than the stainless steel stent (11.50 ± 2.12 atm). Furthermore, the achieved target vessel diameter of the cobalt chromium stent (Visibility-Index QCA/IVUS Multi-Link Vision(®)1.13 / Multi-Link Zeta(® )1.04) is more easily overrated by Quantitative Coronary Analysis. CONCLUSION: These data indicate that stent material-specific recommendations for optimal implantation pressure and different stent material with an equal design should both be considered in interpreting QCA-analysis

Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces

Spin-orbit coupling (SOC) describes the relativistic interaction between the spin and momentum degrees of freedom of electrons, and is central to the rich phenomena observed in condensed matter systems. In recent years, new phases of matter have emerged from the interplay between SOC and low dimensionality, such as chiral spin textures and spin-polarized surface and interface states. These low-dimensional SOC-based realizations are typically robust and can be exploited at room temperature. Here we discuss SOC as a means of producing such fundamentally new physical phenomena in thin films and heterostructures. We put into context the technological promise of these material classes for developing spin-based device applications at room temperature

The predictive significance of CD20 expression in B-cell lymphomas

<p>Abstract</p> <p>Background</p> <p>In our recent study, we determined the cut-off value of CD20 expression at the level of 25 000 molecules of equivalent soluble fluorochrome (MESF) to be the predictor of response to rituximab containing treatment in patients with B-cell lymphomas. In 17.5% of patients, who had the level of CD20 expression below the cut-off value, the response to rituximab containing treatment was significantly worse than in the rest of the patients with the level of CD20 expression above the cut-off value. The proportion of patients with low CD20 expression who might not benefit from rituximab containing treatment was not necessarily representative. Therefore the aim of this study was to quantify the CD20 expression in a larger series of patients with B-cell lymphomas which might allow us to determine more reliably the proportion of patients with the CD20 expression below the cut-off.</p> <p>Methods</p> <p>Cytological samples of 64 diffuse large B-cell lymphomas (DLBCL), 56 follicular lymphomas (FL), 31 chronic lymphocytic leukemias (CLL), 34 mantle cell lymphomas (MCL), 18 marginal zone lymphomas (MZL) and 15 B-cell lymphomas unclassified were analyzed for CD20 expression by quantitative four-color flow cytometric measurements using FACSCalibur flow cytometer (BD Biosciences).</p> <p>Results</p> <p>The range of CD20 expression in different B-cell lymphomas was very broad, varying from 2 737 to 115 623 MESF in CLL and 3 549 to 679 577 MESF in DLBCL. However, when we compared the CD20 expression in the groups of patients with DLBCL, FL, MCL, MZL, CLL and B-cell lymphomas unclassified, it was found to be significantly lower (p = 0.002) only in CLL but did not significantly differ in other lymphoma types (p = NS). Fifty-three out of 218 (24.3%) patients with B-cell lymphomas had the CD20 expression below the cut-off value.</p> <p>Conclusions</p> <p>The CD20 expression in CLL is significantly lower than in most histological types of mature B-cell lymphomas in which it appears to be comparable. Approximately 25% of B-cell lymphoma patients have the CD20 expression below the cut-off value showing that the low CD20 expression might be more common than presumed from our previous study.</p