Hyperbaric oxygenation improve red blood cell deformability in patients with acute or chronic inflammation.

INTRODUCTION: Red blood cells (RBC) are one of the key elements of the microcirculation. Their ability to pass through capillaries and to deliver oxygen to cells is due to their large degree of deformability linked to the characteristics of the RBC membrane. Alterations in RBC deformability as a result of membrane damage, linked in part to increased synthesis of reactive oxygen species (ROS), can be observed in several diseases, such as sepsis, and may contribute to the altered microcirculation observed in these pathologies. Hyperbaric oxygen therapy (HBOT), with inhalation of 100 % oxygen, has been proposed in several acute or chronic pathologies, including carbon monoxide poisoning. OBJECTIVE: We investigated the effects of HBOT on oxidative stress from ROS produced by myeloperoxidase (MPO) and on RBC deformability in patients with acute or chronic inflammation (n = 10), in patients with acute carbon monoxide poisoning (n = 10), and in healthy volunteers (n = 10). METHODS: RBC deformability was evaluated before and after HBOT in the various populations using the ektacytometry technique (Laser-assisted Optical Rotational Red Cell Analyzer - LORRCA). Deformability was determined by the elongation index (EI) in relation to the shear stress (SS) over a range of 0.3 to 50 Pa. Oxidative stress was estimated through changes in proteins (chlorotyrosine and homocitrulline) induced by MPO activity measured by liquid chromatography-tandem mass spectrometry analysis. RESULTS: Before HBOT, EI was significantly lower in patients with acute or chronic inflammation than in healthy volunteers and patients with acute carbon monoxide poisoning for the majority of SS values studied. After one session of HBOT, the EI was significantly higher than before HBOT for SS values of 1.93 Pa or higher in patients with acute or chronic inflammation. This effect remains constant after 10 sessions. There were no differences before and after HBOT in protein or amino acid oxidation due to ROS generation mediated by MPO in the three populations. CONCLUSIONS: Our results confirm altered RBC deformability in patients with acute and chronic conditions associated with an underlying inflammatory process. HBOT improves deformability only after one session and therefore may improve microcirculation in this population. According to our results, this improvement does not seem mediated by the ROS pathway via MPO. These results need to be confirmed in a larger population.

Changes in Population-Level and Institutional-Level Prescribing Habits of Radioiodine Therapy for Papillary Thyroid Cancer.

Background: In the past two decades, new evidence and guidelines have emerged to refine recommendations for the use of radioactive iodine (RAI) therapy after thyroidectomy for cancer. We aim to describe national trends in RAI utilization, assess the impact of individual hospitals on RAI utilization, and examine whether variation in prescribing habits has declined over time. Methods: The National Cancer Database (NCDB) was queried from 2004 to 2016 for patients with papillary thyroid cancer (PTC) who received total thyroidectomy. Trends were analyzed using Joinpoint analysis. Hospital-specific effects and variation in prescribing habits were assessed through a hierarchical, mixed regression model. Results: RAI utilization declined from 61.0% in 2004 to 43.9% in 2016. RAI use declined most profoundly in patients with T1a, N0/X, M0 PTC without extrathyroidal extension (34.8% in 2004 to 9.5% in 2015), but continues to be used commonly in patients with advanced disease for whom it is routinely recommended (73.4% in 2004 to 72.0% in 2015). Furthermore, ∼80% of hospitals in 2016 utilized at or below the median utilization rate in 2006. Variation in RAI utilization across hospitals decreased by ∼50% from 2004 to 2016 (Levene's test p < 0.001), with a significant decline (p = 0.002) in the variation after 2012 (confidence interval: 2010 to 2014). Conclusions: Recommendations for whom to prescribe RAI appear to have impacted both the number of patients receiving RAI and the variation in prescribing habits across hospitals. Hospital selection has contributed less to the probability of receiving RAI over time.

Practice Patterns and Guideline Non-Adherence in Surgical Management of Appendiceal Carcinoid Tumors.

BACKGROUND: Surgical management of appendiceal carcinoid tumors is heavily debated, despite National Comprehensive Cancer Network guidelines recommending aggressive resection of tumors >2 cm. We investigated national practice patterns and the predictors and impact of guideline non-adherence. STUDY DESIGN: The National Cancer Database was queried for cases of appendiceal carcinoids diagnosed from 2004 to 2015 treated with either appendectomy or hemicolectomy. Multivariable logistic regression, adjusted for demographic and clinical factors, identified associations with the procedure type among patients stratified by tumor size ≤2 cm and >2 cm. Cox Proportional Hazards then identified associations with overall survival among stratified patient groups. RESULTS: Of 3,198 cases of appendiceal carcinoids, 1,893 appendectomies and 1,305 hemicolectomies were identified. Contrary to National Comprehensive Cancer Network guidelines, 32.4% of tumors ≤2 cm were treated with hemicolectomy and 31.3% of tumors >2 cm were treated with definitive appendectomy. Hemicolectomy for small tumors was associated with age 65 years and older (odds ratio [OR] 2.4; 95% CI 1.7 to 3.3; reference group age 18 to 39 years), history of malignancy (OR 2.0; 95% CI 1.6 to 2.6), tumor size 1.1 to 2 cm (OR 2.8; 95% CI 2.3 to 3.4; reference group size ≤1 cm), and lymphovascular invasion (OR 2.2; 95% CI 1.6 to 3.2); appendectomy for large tumors was associated with age 65 years and older only (OR 2.2; 95% CI 1.1 to 4.2). Procedure type was not associated with survival for small or large tumors (hazard ratio 1.0; 95% CI 0.7 to 1.4 and hazard ratio 1.1; 95% CI 0.6 to 2.0, respectively). CONCLUSIONS: Despite well-known size-based treatment guidelines for appendiceal carcinoids, one-third of patients in the US undergo hemicolectomy for small tumors and appendectomy for large tumors. Guideline non-adherence, however, is not associated with overall survival. Reasons for these practice patterns should be explored, and guidelines revisited.

Synthetic mimicking of plant oils and comparison with naturally grown products in polyurethane synthesis.

The use of plant oils as industrial feedstocks can often be hampered by their lack of optimization towards a particular process, as well as their development being risky; growing suitable volumes of crops to test can take up to five years. To circumvent this, we aimed to discover a method that would mimic plant oil profiles in the laboratory, and show that they exhibited similar properties to the naturally grown plant oils in a given process. Using the synthesis of polyurethanes as an example, we have synthesized six different polymers and demonstrated that plant oils will produce polymers with similar physical properties to those oils mimicked in the laboratory. The use of this mimicking process can be extended to other types of polymers to obtain a method for predicting the properties of a given material based on the plant oil composition of a crop before it is grown in bulk.