Intra-laboratory analytical variability of biochemical markers of fibrosis (Fibrotest) and activity (Actitest) and reference ranges in healthy blood donors.

Combinations of tests comprising alpha2-macroglobulin, haptoglobin, apolipoprotein Al, gamma-glutamyltransferase, total bilirubin (Fibrotest) and alanine aminotransferase (Actitest) are being developed as alternatives to liver biopsy in patients with chronic hepatitis C. The aim of this study was to assess in the same laboratory the impact of parameter assay variations on Fibrotest and Actitest results and intra-patient reproducibility of the two tests. The stability of the samples for each test was studied after storage at -80 degrees C and -20 degrees C. Within-run, between-run and total imprecision for each parameter assay, and for Fibrotest and Actitest results, were determined. Transferability of assay results between different analyzers was studied. Intra-patient reproducibility was assessed in 55 hospitalized patients. Fibrotest and Actitest reference ranges were determined in 300 blood donors (reference group). The stability of the parameters was affected by serum storage at -20 degrees C only. The impact of parameter analytical variability on Fibrotest and Actitest results was less than 10% and intra-patient reproducibility was acceptable (p > 0.05). The transferability between different analyzers of results of assays performed under the same standardized and calibration conditions was excellent. Fibrotest and Actitest reference ranges in blood donors were (mean+/-SE) 0.075+/-0.004 and 0.068+/-0.004, respectively. The low intra-laboratory and intra-patient variability in Fibrotest and Actitest results confirm Fibrotest and Actitest reliability.     

Building trophic specializations that result in substantial niche partitioning within a young adaptive radiation

Dietary partitioning often accompanies the increased morphological diversity seen during adaptive radiations within aquatic systems. While such niche partitioning would be expected in older radiations, it is unclear how significant morphological divergence occurs within a shorter time period. Here we show how differential growth in key elements of the feeding mechanism can bring about pronounced functional differences among closely related species. An incredibly young adaptive radiation of three Cyprinodon species residing within hypersaline lakes in San Salvador Island, Bahamas, has recently been described. Characterized by distinct head shapes, gut content analyses revealed three discrete feeding modes in these species: basal detritivory as well as derived durophagy and lepidophagy (scale‐feeding). We dissected, cleared and stained, and micro‐CT scanned species to assess functionally relevant differences in craniofacial musculoskeletal elements. The widespread feeding mode previously described for cyprinodontiforms, in which the force of the bite may be secondary to the requisite dexterity needed to pick at food items, is modified within both the scale specialist and the durophagous species. While the scale specialist has greatly emphasized maxillary retraction, using it to overcome the poor mechanical advantage associated with scale‐eating, the durophage has instead stabilized the maxilla. In all species the bulk of the adductor musculature is composed of AM A1. However, the combined masses of both adductor mandibulae (AM) A1 and A3 in the scale specialist were five times that of the other species, showing the importance of growth in functional divergence. The scale specialist combines plesiomorphic jaw mechanisms with both a hypertrophied AM A1 and a slightly modified maxillary anatomy (with substantial functional implications) to generate a bite that is both strong and allows a wide range of motion in the upper jaw, two attributes that normally tradeoff mechanically. Thus, a significant feeding innovation (scale‐eating, rarely seen in fishes) may evolve based largely on allometric changes in ancestral structures. Alternatively, the durophage shows reduced growth with foreshortened jaws that are stabilized by an immobile maxilla. Overall, scale specialists showed the most divergent morphology, suggesting that selection for scale‐biting might be stronger or act on a greater number of traits than selection for either detritivory or durophagy. The scale specialist has colonized an adaptive peak that few lineages have climbed. Thus, heterochronic changes in growth can quickly produce functionally relevant change among closely related species.     

Loss of SMARCE1 expression is a specific diagnostic marker of clear cell meningioma: a comprehensive immunophenotypical and molecular analysis

Clear cell meningioma (CCM) is a rare grade II histopathological subtype that usually occurs in young patients and displays high recurrence rate. Germline SMARCE1 mutations have been described in hereditary forms of this disease and more recently in small syndromic and sporadic CCM series. The diagnostic value of SMARCE1 in distinguishing between CCM and other meningioma variants has not been yet established. The aim of our study was to investigate the status of SMARCE1 in a series of CCMs and its morphological mimickers. We compared the performance of an anti‐SMARCE1 antibody and the molecular analysis of the SMARCE1 gene in a retrospective multicenter series of CCMs. All CCMs lossed SMARCE1 immunoexpression. Bi‐allelic inactivating events were found by NGS‐based sequencing in all of these cases, except for one, which was incompletely explored, but had a wild‐type sequence. We then validated the anti‐SMARCE1 antibody specificity by analyzing additional 305 pediatric and adult meningiomas of various subtypes and 15 non‐meningioma clear cell tumors by SMARCE1 immunohistochemistry. A nuclear immunostaining was preserved in all other meningioma variants, as well as non‐meningioma clear cell tumors. In conclusion, our series showed, for the first time, that SMARCE1 immunostaining is a highly sensitive biomarker for CCM, useful as a routine diagnostic biomarker.     

Phenotype in girls and women with Turner syndrome: Association between dysmorphic features,karyotype and cardio-aortic malformations

Introduction

Turner syndrome (TS) is a genetic disorder characterized by the (partial) absence or a structural aberration of the second sex chromosome and is associated with a variety of phenotypes with specific physical features and cardio-aortic malformations. The objective of this study was to gain a better insight into the differences in dysmorphic features between girls and women with TS and to explore the association between these features, karyotype and cardio-aortic malformations.

Extracorporeal carbon dioxide removal requirements for ultraprotective mechanical ventilation: Mathematical model predictions

Extracorporeal carbon dioxide (CO₂) removal (ECCO₂R) facilitates the use of low tidal volumes during protective or ultraprotective mechanical ventilation when managing patients with acute respiratory distress syndrome (ARDS); however, the rate of ECCO₂R required to avoid hypercapnia remains unclear. We calculated ECCO₂R rate requirements to maintain arterial partial pressure of CO₂ (PaCO₂) at clinically desirable levels in mechanically ventilated ARDS patients using a six-compartment mathematical model of CO₂ and oxygen (O₂) biochemistry and whole-body transport with the inclusion of an ECCO₂R device for extracorporeal veno-venous removal of CO₂. The model assumes steady state conditions. Model compartments were lung capillary blood, arterial blood, venous blood, post-ECCO₂R venous blood, interstitial fluid and tissue cells, with CO₂ and O₂ distribution within each compartment; biochemistry included equilibrium among bicarbonate and non-bicarbonate buffers and CO₂ and O₂ binding to hemoglobin to elucidate Bohr and Haldane effects. O₂ consumption and CO₂ production rates were assumed proportional to predicted body weight (PBW) and adjusted to achieve reported arterial partial pressure of O₂ and a PaCO₂ level of 46 mmHg at a tidal volume of 7.6 mL/kg PBW in the absence of an ECCO₂R device based on average data from LUNG SAFE. Model calculations showed that ECCO₂R rates required to achieve mild permissive hypercapnia (PaCO₂ of 46 mmHg) at a ventilation frequency or respiratory rate of 20.8/min during mechanical ventilation increased when tidal volumes decreased from 7.6 to 3 mL/kg PBW. Higher ECCO2R rates were required to achieve normocapnia (PaCO2 of 40 mmHg). Model calculations also showed that required ECCO2R rates were lower when ventilation frequencies were increased from 20.8/min to 26/min. The current mathematical model predicts that ECCO2R rates resulting in clinically desirable PaCO2 levels at tidal volumes of 5-6 mL/kg PBW can likely be achieved in mechanically ventilated ARDS patients with current technologies; use of ultraprotective tidal volumes (3-4 mL/kg PBW) may be challenging unless high mechanical ventilation frequencies are used.     

A murine model of Staphylococcus aureus infected chronic diabetic wound: A new tool to develop alternative therapeutics

Diabetic wound infection is a frequent complication that may result in limb amputation. To develop new treatment strategies in response to increasing bacterial resistance, animal models are needed. We created a diabetic mouse model with chronically infected wounds. Diabetes was induced using streptozotocin, and wounds were performed using a biopsy punch, and then infected with a clinical strain of Staphylococcus aureus. Chronification was reached by delaying healing thanks to chemical products (aminotriazole and mercaptosuccinic acid). Overall survival, as well as clinical, bacteriological and immunological data in skin, blood and spleens were collected at days 1, 7, and 14 after wounding. After a transient bacteremia proved by bacteria presence in spleen and kidneys in the first days after wounding, infected mice showed a chronic infection, with a bioburden impairing the healing process, and bacteria persistence compared to control mice. Infected mice showed gradual increasing skin levels of IL‐17A compared to control mice that resulted in an IL‐17/IFN‐γ inbalance, pointing out a localized Th17 polarization of the immune response. Whether infected or not, the skin level of IL‐10 decreased dramatically at days 1 and 7 after wounding, with an increase observed only in the control mice at day 14. After a decrease at day 1 in both groups, spleen IL‐10 showed a rather steady level at days 7 and 14 in the control group compared with the decrease observed in the infected group. The spleen IL‐10/IFN‐γ ratio showed a systemic inflammatory response with Th1 polarization. Therefore, this model provides useful data to study wound healing. It is easy to reproduce, affordable and offers clinical and biological tools to evaluate new therapeutics.