Acute respiratory distress syndrome Gaudry, Stéphane; Ricard, Jean-Damien; Dreyfuss, Didier
La revue du praticien
62, Issue:
9
Magazine Article
Acute respiratory distress syndrome (ARDS) is a permeability pulmonary edema due to lung injury from various causes. In 2012, a new definition, taking into account the degree of hypoxemia and the ...level of positive end-expiratory pressure (PEEP), was published. In addition to progress in the support of organ failures in intensive care, mortality in patients suffering from ARDS has decreased significantly. This improved prognosis is also due to the advent of protective mechanical ventilation that has limited ventilator-induced lung injury (VILI). The treatment of ARDS consists on causative treatment and a strategy of protective ventilation associated with a PEEP level between 10 and 15 cm H20 and the use of prone position or inhaled nitric oxide in the severest cases. The role of extracorporeal membrane oxygenation as adjuvant therapy in ARDS remains unclear.
Internal biliary stenting during biliary reconstruction in liver transplantation decrease anastomotic biliary complications. Implantation of a resorbable internal biliary stent (RIBS) is interesting ...since it would avoid an ablation gesture. The objective of present work was to evaluate adequacy of selected PLA‐b‐PEG‐b‐PLA copolymers for RIBS aimed to secure biliary anastomose during healing and prevent complications, such as bile leak and stricture. The kinetics of degradation and mechanical properties of a RIBS prototype were evaluated with respect to the main bile duct stenting requirements in liver transplantation. For this purpose, RIBS degradation under biliary mimicking solution versus standard phosphate buffer control solution was discussed. Morphological changes, mass loss, water uptake, molecular weight, permeability, pH variations, and mechanical properties were examined over time. The permeability and mechanical properties were evaluated under simulated biliary conditions to explore the usefulness of a PLA‐b‐PEG‐b‐PLA RIBS to secure biliary anastomosis. Results showed no pH influence on the kinetics of degradation, with degradable RIBS remaining impermeable for at least 8 weeks, and keeping its mechanical properties for 10 weeks. Complete degradation is reached at 6 months. PLA‐b‐PEG‐b‐PLA RIBS have the required in vitro degradation characteristics to secure biliary anastomosis in liver transplantation and envision in vivo applications.
Background
Plain radiographic measures of the acetabulum may fail to accurately define coverage or pathomorphology such as impingement or dysplasia. CT scans might provide more precise measurements ...for overcoverage and undercoverage. However, a well-defined method for such CT-based measurements and normative data regarding CT-based acetabular coverage is lacking.
Questions/purposes
The purposes of the study were (1) to develop a method for evaluation of percent coverage of the femoral head by the acetabulum; and (2) to define normative data using a cohort of asymptomatic patient hip and pelvic CT scans and evaluate the variability in acetabular version for asymptomatic patients with normal lateral coverage (lateral center-edge angle LCEA 20°–40°) that has previously been defined as abnormal based on radiographic parameters.
Methods
Two-hundred thirty-seven patients (474 hips) with hip CT scans obtained for reasons other than hip-related pain were evaluated. The scans were obtained from a hospital database of patients who underwent CT evaluation of abdominal trauma or pain. In addition, hips with obvious dysplasia (LCEA < 20°) or profunda (LCE > 40°) were excluded resulting in a final cohort of 222 patients (409 hips 115 men, 107 women) with CT scans and a mean age of 25 ± 3 years. CT scan alignment was corrected along the horizontal and vertical axis and percent acetabular coverage around the clockface (3 o’clock = anterior), and regional (anterior, superior, posterior) and global surface area coverage was determined. Percent coverage laterally was correlated with the LCEA and the presence and prevalence of cranial retroversion (crossover sign) and a positive posterior wall sign were determined.
Results
The mean regional percent femoral head surface area coverage for the asymptomatic cohort was 40% ± 2% anteriorly, 61% ± 3% superiorly, and 48% ± 3% posteriorly. Mean global coverage of the femoral head was 40% ± 2%. The local coverage anteriorly (3 o’clock) was 38% ± 3%, laterally (12 o’clock) was 67% ± 2%, and posteriorly (9 o’clock) was 52% ± 3%. The mean lateral coverage represented a mean LCEA of 31° (± 1 SD). Fifteen percent of hips demonstrated cranial retroversion that would correlate with a crossover sign, and 30% had < 50% posterior coverage that would correlate with a positive posterior wall sign on an anteroposterior pelvis radiograph. In addition, male hips had a higher prevalence of a crossover sign (19%; 95% confidence interval CI, 14%–25% versus 11%; 95% CI, 7%–16%; p = 0.03) and posterior wall sign (46%; 95% CI. 39%–53% versus 13%; 95% CI, 9%–19%; p < 0.001) compared with women. A positive crossover sign or posterior wall sign was present for 113 male hips (53%; 95% CI, 46%–60%) compared with 39 female hips (20%; 95% CI, 15%–26%; p < 0.001).
Conclusions
This study provides normative coverage data and a reproducible method for evaluating acetabular coverage. Cranial acetabular retroversion (crossover sign) and a positive posterior wall sign were frequent findings in a young asymptomatic cohort and might be a normal variant rather than pathologic in a significant number of cases.
Level of Evidence
Level III, diagnostic study.
Adenosine is an endogenous nucleoside which strongly impacts the cardiovascular system. Adenosine is released mostly by endothelial cells and myocytes during ischemia or hypoxia and greatly regulates ...the cardiovascular system via four specific G-protein-coupled receptors named A
R, A
R, A
R, and A
R. Among them, A
subtypes are strongly expressed in coronary tissues, and their activation increases coronary blood flow via the production of cAMP in smooth muscle cells. A
receptor modulators are an opportunity for intense research by the pharmaceutical industry to develop new cardiovascular therapies. Most innovative therapies are mediated by the modulation of adenosine release and/or the activation of the A
receptor subtypes. This review aims to focus on the specific exploration of the adenosine plasma level and its relationship with the A
receptor, which seems a promising biomarker for a diagnostic and/or a therapeutic tool for the screening and management of coronary artery disease. Finally, a recent class of selective adenosine receptor ligands has emerged, and A
receptor agonists/antagonists are useful tools to improve the management of patients suffering from coronary artery disease.
Background:
Various surgical techniques to treat posterolateral knee instability have been described. To date, the recommended treatment is an anatomic form of reconstruction in which the 3 key ...structures of the posterolateral corner (PLC) are addressed: the popliteofibular ligament, the popliteus tendon, and the lateral collateral ligament.
Purpose/Hypothesis:
The purpose of this study was to identify the role of each key structure of the PLC in kinematics of the knee and to biomechanically analyze a single-graft, fibular-based reconstruction that replicates the femoral insertions of the lateral collateral ligament and popliteus to repair the PLC. The hypothesis was that knee kinematics can be reasonably restored using a single graft with a 2-strand “modified Larson” technique.
Study Design:
Descriptive laboratory study.
Methods:
Eight fresh-frozen cadaveric knees were used in this study. We conducted sequential sectioning of the popliteofibular ligament (PFL) and then subsequently the popliteal tendon (PT), the lateral collateral ligament (LCL), and the anterior cruciate ligament (ACL). We then reconstructed the ACL first and then the posterolateral corner using the modified Larson technique. A surgical navigation system was used to measure varus laxity and external rotation at 0°, 30°, 60°, and 90° with a 9.8-N·m varus stress and 5-N·m external rotation force applied to the tibia.
Results:
In extension, varus laxity increased only after the sectioning of the lateral collateral ligament. At 30° of flexion, external rotation in varus and translation of the lateral tibial plateau increased after the isolated popliteofibular ligament section. From 60° to 90° of flexion, translation and mobility of the lateral plateau section increased after sectioning of the PFL. After reconstruction, we observed a restoration of external varus rotation in extension and translation of the lateral tibial plateau at 90° of flexion. This technique provided kinematics similar to the normal knee.
Conclusion:
The PFL has a key role between 30° and 90° of flexion, and the lateral collateral ligament plays a role in extension. Reconstruction with the modified Larson technique restores these 2 complementary stabilizers of the knee.
Clinical Relevance:
Although there are many different techniques to reconstruct the PLC-deficient knee, this study indicates that a single-graft, fibular-based reconstruction of the LCL and PT may restore varus and external rotation laxity to the knee.
Due to frequent mutations in certain cancers, FGFR3 gene is considered as an oncogene. However, in some normal tissues, FGFR3 can limit cell growth and promote cell differentiation. Thus, FGFR3 ...action appears paradoxical.
FGFR3 expression was forced in pancreatic cell lines. The receptor exerted dual effects: it suppressed tumor growth in pancreatic epithelial-like cells and had oncogenic properties in pancreatic mesenchymal-like cells. Distinct exclusive pathways were activated, STATs in epithelial-like cells and MAP Kinases in mesenchymal-like cells. Both FGFR3 splice variants had similar effects and used the same intracellular signaling. In human pancreatic carcinoma tissues, levels of FGFR3 dropped in tumors.
In tumors from epithelial origin, FGFR3 signal can limit tumor growth, explaining why the 4p16.3 locus bearing FGFR3 is frequently lost and why activating mutations of FGFR3 in benign or low grade tumors of epithelial origin are associated with good prognosis. The new hypothesis that FGFR3 can harbor both tumor suppressive and oncogenic properties is crucial in the context of targeted therapies involving specific tyrosine kinase inhibitors (TKIs). TKIs against FGFR3 might result in adverse effects if used in the wrong cell context.
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