Reproducibility and reliability of central corneal thickness determination in more and less profound corneal edema using ultrasound pachymetry,a Scheimpflug camera and anterior segment OCT

Graefe's Archive for Clinical and Experimental Ophthalmology - The purpose of this study is to determine the influence of different degrees of corneal edema on the reliability and...     

Transfer of learning and patient outcome in simulated crisis resource management: a systematic review

Purpose

Simulation-based learning is increasingly used by healthcare professionals as a safe method to learn and practice non-technical skills, such as communication and leadership, required for effective crisis resource management (CRM). This systematic review was conducted to gain a better understanding of the impact of simulation-based CRM teaching on transfer of learning to the workplace and subsequent changes in patient outcomes.

Source

Studies on CRM, crisis management, crew resource management, teamwork, and simulation published up to September 2012 were searched in MEDLINE^®, EMBASE?, CINAHL, Cochrane Central Register of Controlled Trials, and ERIC. All studies that used simulation-based CRM teaching with outcomes measured at Kirkpatrick Level 3 (transfer of learning to the workplace) or 4 (patient outcome) were included. Studies measuring only learners’ reactions or simple learning (Kirkpatrick Level 1 or 2, respectively) were excluded. Two authors independently reviewed all identified titles and abstracts for eligibility.

Principal findings

Nine articles were identified as meeting the inclusion criteria. Four studies measured transfer of simulation-based CRM learning into the clinical setting (Kirkpatrick Level 3). In three of these studies, simulation-enhanced CRM training was found significantly more effective than no intervention or didactic teaching. Five studies measured patient outcomes (Kirkpatrick Level 4). Only one of these studies found that simulation-based CRM training made a clearly significant impact on patient mortality.

Conclusions

Based on a small number of studies, this systematic review found that CRM skills learned at the simulation centre are transferred to clinical settings, and the acquired CRM skills may translate to improved patient outcomes, including a decrease in mortality.     

Morphometric study of the scapular free flap and the free rib osteomyocutaneous flap

The scapula free flap is often the first choice for reconstruction of bony defects of the facial skeleton. However, the vascularised rib as part of a free rib osteomyocutaneous flap may be a suitable second choice. We have investigated the morphology and clinical dimensions of the 7th rib and the scapula, and the ability of the available bone to carry dental implants. The age and sex of the cadaver, and the donor side, were also recorded. The dimensions of the scapulas and 7th ribs (n = 130 of each) from 65 cadavers were measured at 4 different points using osteometric methods. Examination showed that bone from the scapula and 7th rib were sufficient for placement of implants. The 7th rib gave reliable measurements for both height and width, and a consistent relation between compact and cancellous bone. Although the scapula provided adequate compact and cancellous bone, there were variations depending on the segment of bone chosen. Bones from male cadavers were more suitable for implantation. In both the scapula and the 7th rib ageing had a significant adverse effect in only one dimension. Most points of measurement have satisfactory bony dimensions for insertion of dental implants.     

Induction of IL-6 and MMP-8 in human periodontal fibroblasts by static tensile strain

Objectives

Mechanical loading is a potential activator of inflammation and able to stimulate factors for periodontal and alveolar bone destruction. Aim of this study was to investigate the inflammatory response and synthesis of proteinases by human periodontal ligament fibroblast (HPdLF) dependent on different strengths of static tensile strain (STS).

Materials and methods

HPdLFs were loaded with different STS strengths (1, 5, and 10 %) in vitro. Gene expressions of cyclooxygenase (COX)-2 and interleukin (IL)-6 were analyzed by quantitative real-time polymerase chain reaction. Production of IL-6, prostaglandin E₂ (PGE₂), matrix metalloproteinase (MMP)-8, and tissue inhibitors of matrix metalloproteinase (TIMP)-1 were measured by enzyme-linked immunosorbent assay. Receptor activator of nuclear factor-kappa ligand (RANKL) synthesis was detected by immunocytochemical staining.

Results

Ten percent STS led to an increased gene expression of IL-6 and COX-2 (34.4-fold) in HPdLF, and 1 and 5 % STS slightly reduced the gene expression of IL-6. Synthesis of IL-6 was significantly reduced by 1 % STS and stimulated by 10 % STS. Ten percent STS significantly induced PGE₂ production. RANKL was not detectable at any strength of STS. MMP-8 synthesis showed significantly higher values only at 10 % STS, but TIMP-1 was stimulated by 5 and 10 % STS, resulting into highest TIMP-1/MMP-8 ratio at 5 % STS.

Conclusions

High-strength STS is a potent inducer of periodontal inflammation and MMP-8, whereas low-strength STS shows an anti-inflammatory effect. Moderate-strength STS causes the highest TIMP-1/MMP-8 ratio, leading to appropriate conditions for reformation of the extracellular matrix.

Clinical relevance

Furthermore, this study points out that the strength of force plays a pivotal role to achieve orthodontic tooth movement without inducing periodontal inflammation and to activate extracellular matrix regeneration.     

Differential impact of belatacept and cyclosporine A on central aortic blood pressure and arterial stiffness after renal transplantation

Calcineurin inhibitors (CNI) are potent vasoconstrictors and induce an acceleration of arteriosclerosis, thus contributing to the cardiovascular risk after renal transplantation. The study compares the impact of belatacept and cyclosporine A (CsA) on arterial stiffness and central aortic blood pressure. We performed a case–control study in 46 patients (23 on belatacept and 23 on CsA) matched for age, body mass index, time after transplantation, and time on dialysis prior to transplantation. Pulse wave analysis (SphygmoCor, AtCor^®) was used to assess central aortic blood pressure, aortic augmentation pressure, and pulse wave velocity (PWV) as a marker of arterial stiffness. Assessment of vascular function was performed after a minimum of 20 months and a median follow‐up of 81 months post‐transplant. Peripheral systolic and diastolic blood pressure did not significantly differ in the two groups (p > 0.05 each). The central aortic augmentation pressure was higher in the CsA group (12.7 mmHg vs. 7.3 mmHg, p = 0.048). PWV as a measure of arterial stiffness did not differ in the two groups. Thus, belatacept is not associated with a significant difference in arterial stiffness compared to CsA after a median of 81 months post‐transplant. It is associated, however, with a lower aortic augmentation pressure, a strong independent cardiovascular risk factor.     

Prise en charge des tumeurs neuroendocrines de l’intestin grêle

For neuroendocrine tumour of the small bowel treatment’s goals are to control the secretory syndrome and to cure the tumour. Carcinoid syndrome is usually due to metastatic spread to the liver. Control of this syndrome with somatostatin analogs is a priority. Even if there is metastatic spread, surgical treatment of the primitive tumour should be discussed in cases of retractile mesenteritis, small bowel ischemia or subocclusive syndrome in order to avoid any acute local complication. Surgical treatment of intrahepatic lesions is an option only if a complete resection of all lesions seems possible, and, if liver resection has to be large, an observation period is advisable. Embolisation is the best option if liver metastases are not resectable, with no extrahepatic lesions. Diffuse and non-evolving lesions should simply be monitored or treated with somatostatin analogs. Interferon, chemotherapy, peptide receptor radionuclide therapy should be proposed only in cases of demonstrated progressing lesions or uncontrolled carcinoid syndrome. Finally, it has to be emphasized that it is of the utmost importance to enrol those patients with very rare disease in prospective clinical trials currently open in France (Telestar, Evacel, Sunland, Netter-1).     

The effect of mode of agitation and type of plastic bag on storage characteristics and in vivo kinetics of platelet concentrates

We studied the characteristics of platelet concentrates stored for 5 days at 22 degrees C. Platelets were prepared in three plastic bags (PL 732, PL 1240, and CLX) and stored on one of four platelet agitators, 1- or 6-rpm elliptical and 2- or 6-rpm circular rotators. A total of 76 studies were divided among 12 groups, each group being composed of a different storage bag-rotator combination. In vivo recovery and survival were calculated using Indium-111 oxine-labeled platelets injected into autologous volunteers. Platelet recovery was assessed at 2 hours postinjection or as the y-intercept of the multiple-hit model survival curve. Survival was calculated using linear, exponential, and multiple-hit computer models. Linear T 1/2 also was calculated as an index of platelet survival. At 5 days, the pH of all concentrates was above pH 7.0 and platelet counts were above 5.5 X 10(10) per bag except for the PL 732 with the 6-rpm elliptical rotator, which was 4.6 X 10(10) per bag. This combination also showed a significantly higher poststorage lactic dehydrogenase (LDH) discharge compared to the mean of the other 11 groups (23.6 +/- 5.4% vs. 10.4 +/- 3.0%, p less than 0.05); however, the beta-thromboglobulin (beta-TG) release was not statistically different.(ABSTRACT TRUNCATED AT 250 WORDS)     

MHC class II–restricted antigen presentation by plasmacytoid dendritic cells inhibits T cell–mediated autoimmunity

Although plasmacytoid dendritic cells (pDCs) express major histocompatibility complex class II (MHCII) molecules, and can capture, process, and present antigens (Ags), direct demonstrations that they function as professional Ag-presenting cells (APCs) in vivo during ongoing immune responses remain lacking. We demonstrate that mice exhibiting a selective abrogation of MHCII expression by pDCs develop exacerbated experimental autoimmune encephalomyelitis (EAE) as a consequence of enhanced priming of encephalitogenic CD4⁺ T cell responses in secondary lymphoid tissues. After EAE induction, pDCs are recruited to lymph nodes and establish MHCII-dependent myelin-Ag–specific contacts with CD4⁺ T cells. These interactions promote the selective expansion of myelin-Ag–specific natural regulatory T cells that dampen the autoimmune T cell response. pDCs thus function as APCs during the course of EAE and confer a natural protection against autoimmune disease development that is mediated directly by their ability to present of Ags to CD4⁺ T cells in vivo.Conventional DCs (cDCs) play well established roles in the induction of immunity and tolerance. Both functions require antigen (Ag)-specific interactions between T cells and cDCs in secondary lymphoid tissues. The outcome of these interactions depends on the modulation and integration of three signals: TCR engagement by peptide–MHC complexes, the recruitment of costimulatory and adhesion molecules, and the delivery of soluble mediators (Lebedeva et al., 2005). Under steady-state conditions, cDCs reside in peripheral tissues and lymphoid organs in an immature state characterized by low cell surface expression of MHC class II (MHCII), costimulatory, and adhesion molecules. Immature cDCs continuously capture and present self-Ags, circulate from tissues to lymphoid organs, and maintain tolerance by inducing the deletion of autoreactive T cells or the development of regulatory T cells (T reg cells; Steinman et al., 2003). Signals associated with inflammation, infections, or tissue damage induce cDC maturation, a process involving complex phenotypical changes, including the up-regulation of MHCII, costimulatory, and adhesion molecules, the secretion of inflammatory mediators, and altered migratory properties. Activation of naive T cells by mature cDCs results in clonal expansion and differentiation into effector and memory T cells.Plasmacytoid DCs (pDCs) constitute a unique DC subtype found mainly in the blood and secondary lymphoid organs. The activation of pDCs by infections triggers the secretion of large quantities of type I IFN, suggesting that they have crucial innate functions (Colonna et al., 2004). However, pDCs also express MHCII molecules and undergo a maturation process similar to that of cDCs (Villadangos and Young, 2008). Furthermore, pDCs can internalize, process, and present Ags to CD4⁺ T cells and cross-present Ags to CD8⁺ T cells (Hoeffel et al., 2007; Sapoznikov et al., 2007; Di Pucchio et al., 2008; Young et al., 2008). These findings had suggested that pDCs can function as APCs. However, whether pDCs indeed function as APCs in vivo during ongoing immune responses, and whether this promotes T cell–mediated immunity and/or the maintenance of self-tolerance, remained unsolved issues.pDCs can participate in the maintenance of peripheral tolerance. The induction of T reg cells by pDCs was shown to confer tolerance to cardiac allografts, prevent asthmatic reactions to inhaled Ags, and protect against graft versus host disease (de Heer et al., 2004; Ochando et al., 2006; Hadeiba et al., 2008). pDCs can also induce tolerance by promoting deletion of pathogenic T cells (Goubier et al., 2008) or inhibiting effector CD4⁺ T cell responses in a relapsing model of experimental autoimmune encephalomyelitis (EAE; Bailey-Bucktrout et al., 2008). As these studies relied mainly on antibody-mediated ablation of pDCs, they could not discriminate between innate and adaptive functions of these cells. It therefore remained unknown if pDCs function as tolerogenic APCs in these systems.We have investigated whether MHCII-mediated Ag presentation by pDCs instructs CD4⁺ T cell responses during EAE, a mouse model for multiple sclerosis (MS; Wekerle, 2008). EAE induced by immunization with myelin oligodendrocyte glycoprotein (MOG) was found to be severely exacerbated in mice exhibiting a selective abrogation of MHCII expression by pDCs. Conversely, EAE was dampened by the adoptive transfer of WT, but not MHCII-deficient, pDCs. EAE induction triggered the recruitment of pDCs to LNs, where they engaged in MHCII-dependent and MOG-specific interactions with CD4⁺ T cells. This inhibited the development of pathogenic T cells during the priming phase of the disease by promoting the selective expansion of natural T reg cells. Our results demonstrate that Ag-presentation by pDCs can inhibit T cell–mediated autoimmunity and can thus determine the outcome of adaptive immune responses in vivo.     

An algorithm to improve outcomes of radial forearm flap donor site

Background: Due to the high rate of donor site complications the Radial Forearm Flap (RFF) has lost ground in favor of the Antero-lateral tight flap (ALT) and other flaps. We have designed a reconstruction algorithm for reconstruction of its donor site. The goal of this study was to retrospectively evaluate the impact of this algorithm on RFF donor site complication rates.

Methods: The authors analyzed retrospectively 31 patients who underwent free radial forearm flap reconstruction between November 2009 and May 2013. Donor site complications were compared with data from patients treated before introdutction of the algorithm. Within the group were compared patients in which the flap was harvested suprafascial with those in which the flap was harvested as subfascial.

Results: Before application of the algorithm, there was a 23.3% complication rate at the RFF donor site, in our experience. After introduction of the algorithm, complication rate has dropped to 3.2%, consisting in a partial skin graft necrosis treated by local wound-care and healed without further intervention.

Conclusions: Application of the algorithm described has led to a significant reduction in RFF donor site complication rates. This demonstrates that if flap donor sites are analyzed and tailor treated in the same way as primary defects are, instead of being given secondary importance and just grafted, outcomes improve.