Discontinuation of tyrosine kinase inhibitor in chronic myeloid leukemia: a retrospective cohort in east occitania.

Tyrosine kinase inhibitor (TKI) discontinuation in chronic phase chronic myeloid leukemia (CML) patients has been examined in a real-life setting in the east occitania region of France. We have collected sex, age, prognostic scores, pre-TKI treatment, TKI length and response, relapse data from patients who had stopped TKI in prolonged complete molecular remission (CMR), and analyzed relapse risk factors. Sixty consecutive patients were included from january 2010 to december 2016. Sixteen received pre-TKI treatment. Fifty-three received a first-generation TKI, and seven had a second-generation TKI in first-line therapy. The median TKI time to achieve CMR was 20.5 months [5-137]. The median TKI length before discontinuation treatment was 73 months [12-158]. Twenty-two patients (37%) relapsed with a median time to relapse of 6 months [3-27]. An intermediate or high Sokal score was the only relapse risk factor (HR = 3.32, p < 0.05) associated with relapse after TKI discontinuation. TKI discontinuation was possible without relapse for half of the patients in chronic phase CML. In a real-life cohort, a high-risk Sokal score at diagnosis appears to be an adverse prognosis feature for TKI discontinuation.

Five-year outcomes of rapid-deployment aortic valve replacement with the Edwards Intuity valve.

BACKGROUND: This report presents 5-year outcomes of the rapid-deployment Edwards Intuity valve in a prospective, single-center study. METHODS: All patients who underwent an aortic valve replacement (AVR) with an Edwards Intuity bioprosthesis at La Timone Hospital, Marseille, France, from July 2012 to June 2015 were assessed over a 5-year follow-up period. The primary outcome was overall mortality at 5 years. Secondary outcomes were reoperation, overall mortality and stroke, cardiovascular mortality, composite endpoints defined by the updated Valve Academic Research Consortium-2 (VARC-2), periprosthetic regurgitation, prosthesis-patient mismatch, and the need for new pacemaker implantation. RESULTS: In total, 170 consecutive patients were assessed, of which 67.1% were males. The mean age was 76 years, mean EuroSCORE II was 3.5% and 5-year overall mortality was 12.4%. At 5 years, reoperation was 2.9%, overall mortality and stroke was 4.1% per patient-year, and cardiovascular mortality was 4.7%. VARC clinical efficacy and VARC time-related valve safety were achieved in 46.0% and 59.9% of patients, respectively. At one month VARC device success was 71.2% and VARC early safety was 87.1%. At one year, mild and moderate periprosthetic regurgitation were 2.4% and 0.6%, respectively, and moderate and severe prosthesis-patient mismatch were 18.8% and 4.8%, respectively. Conduction disturbances needing new PPI occurred in 3.5% patients. CONCLUSION: The 5-year outcomes of AVR with the Edwards Intuity valve system demonstrate satisfactory midterm safety and excellent haemodynamic performance.

Kalirin-7 prevents dendritic spine dysgenesis induced by amyloid beta-derived oligomers.

Synapse degeneration and dendritic spine dysgenesis are believed to be crucial early steps in Alzheimer's disease (AD), and correlate with cognitive deficits in AD patients. Soluble amyloid beta (Aß)-derived oligomers, also termed Aß-derived diffusible ligands (ADDLs), accumulate in the brain of AD patients and play a crucial role in AD pathogenesis. ADDLs bind to mature hippocampal neurons, induce structural changes in dendritic spines and contribute to neuronal death. However, mechanisms underlying structural and toxic effects are not fully understood. Here, we report that ADDLs bind to cultured mature cortical pyramidal neurons and induce spine dysgenesis. ADDL treatment induced the rapid depletion of kalirin-7, a brain-specific guanine-nucleotide exchange factor for the small GTPase Rac1, from spines. Kalirin-7 is a key regulator of dendritic spine morphogenesis and maintenance in forebrain pyramidal neurons and here we show that overexpression of kalirin-7 prevents ADDL-induced spine degeneration. Taken together, our results suggest that kalirin-7 may play a role in the early events leading to synapse degeneration, and its pharmacological activation may prevent or delay synapse pathology in AD.

CNTNAP2 stabilizes interneuron dendritic arbors through CASK.

Contactin associated protein-like 2 (CNTNAP2) has emerged as a prominent susceptibility gene implicated in multiple complex neurodevelopmental disorders, including autism spectrum disorders (ASD), intellectual disability (ID), and schizophrenia (SCZ). The presence of seizure comorbidity in many of these cases, as well as inhibitory neuron dysfunction in Cntnap2 knockout (KO) mice, suggests CNTNAP2 may be crucial for proper inhibitory network function. However, underlying cellular mechanisms are unclear. Here we show that cultured Cntnap2 KO mouse neurons exhibit an inhibitory neuron-specific simplification of the dendritic tree. These alterations can be replicated by acute knockdown of CNTNAP2 in mature wild-type (WT) neurons and are caused by faulty dendrite stabilization rather than outgrowth. Using structured illumination microscopy (SIM) and stimulated-emission depletion microscopy (STED), two super-resolution imaging techniques, we uncovered relationships between nanoscale CNTNAP2 protein localization and dendrite arborization patterns. Employing yeast two-hybrid screening, biochemical analysis, in situ proximity ligation assay (PLA), SIM, and phenotype rescue, we show that these effects are mediated at the membrane by the interaction of CNTNAP2's C-terminus with calcium/calmodulin-dependent serine protein kinase (CASK), another ASD/ID risk gene. Finally, we show that adult Cntnap2 KO mice have reduced interneuron dendritic length and branching in particular cortical regions, as well as decreased CASK levels in the cortical membrane fraction. Taken together, our data reveal an interneuron-specific mechanism for dendrite stabilization that may provide a cellular mechanism for inhibitory circuit dysfunction in CNTNAP2-related disorders.

Optimising perioperative care for hip and knee arthroplasty in South Africa: a Delphi consensus study.

BACKGROUND: A structured approach to perioperative patient management based on an enhanced recovery pathway protocol facilitates early recovery and reduces morbidity in high income countries. However, in low- and middle-income countries (LMICs), the feasibility of implementing enhanced recovery pathways and its influence on patient outcomes is scarcely investigated. To inform similar practice in LMICs for total hip and knee arthroplasty, it is necessary to identify potential factors for inclusion in such a programme, appropriate for LMICs. METHODS: Applying a Delphi method, 33 stakeholders (13 arthroplasty surgeons, 12 anaesthetists and 8 physiotherapists) from 10 state hospitals representing 4 South African provinces identified and prioritised i) risk factors associated with poor outcomes, ii) perioperative interventions to improve outcomes and iii) patient and clinical outcomes necessary to benchmark practice for patients scheduled for primary elective unilateral total hip and knee arthroplasty. RESULTS: Thirty of the thirty-three stakeholders completed the 3 months Delphi study. The first round yielded i) 36 suggestions to preoperative risk factors, ii) 14 (preoperative), 18 (intraoperative) and 23 (postoperative) suggestions to best practices for perioperative interventions to improve outcomes and iii) 25 suggestions to important postsurgical outcomes. These items were prioritised by the group in the consecutive rounds and consensus was reached for the top ten priorities for each category. CONCLUSION: The consensus derived risk factors, perioperative interventions and important outcomes will inform the development of a structured, perioperative multidisciplinary enhanced patient care protocol for total hip and knee arthroplasty. It is anticipated that this study will provide the construct necessary for developing pragmatic enhanced care pathways aimed at improving patient outcomes after arthroplasty in LMICs.

Is Conventional Bypass for Coronary Artery Bypass Graft Surgery a Misnomer?

Although recent trials comparing on vs. off-pump revascularization techniques describe cardiopulmonary bypass (CPB) as "conventional," inadequate description and evaluation of how CPB is managed often exist in the peer-reviewed literature. We identify and subsequently describe regional and center-level differences in the techniques and equipment used for conducting CPB in the setting of coronary artery bypass grafting (CABG) surgery. We accessed prospectively collected data among isolated CABG procedures submitted to either the Australian and New Zealand Collaborative Perfusion Registry (ANZCPR) or Perfusion Measures and outcomes (PERForm) Registry between January 1, 2014, and December 31, 2015. Variation in equipment and management practices reflecting key areas of CPB is described across 47 centers (ANZCPR: 9; PERForm: 38). We report average usage (categorical data) or median values (continuous data) at the center-level, along with the minimum and maximum across centers. Three thousand five hundred sixty-two patients were identified in the ANZCPR and 8,450 in PERForm. Substantial variation in equipment usage and CPB management practices existed (within and across registries). Open venous reservoirs were commonly used across both registries (nearly 100%), as were "all-but-cannula" biopassive surface coatings (>90%), whereas roller pumps were more commonly used in ANZCPR (ANZCPR: 85% vs. PERForm: 64%). ANZCPR participants had 640 mL absolute higher net prime volumes, attributed in part to higher total prime volume (1,462 mL vs. 1,217 mL) and lower adoption of retrograde autologous priming (20% vs. 81%). ANZCPR participants had higher nadir hematocrit on CPB (27 vs. 25). Minimal absolute differences existed in exposure to high arterial outflow temperatures (36.6°C vs. 37.0°C). We report substantial center and registry differences in both the type of equipment used and CPB management strategies. These findings suggest that the term "conventional bypass" may not adequately reflect real-world experiences. Instead of using this term, authors should provide key details of the CPB practices used in their patients.

Organizational Contributors to the Variation in Red Blood Cell Transfusion Practices in Cardiac Surgery: Survey Results From the State of Michigan.

BACKGROUND: While large volumes of red blood cell transfusions are given to preserve life for cardiac surgical patients, indications for lower volume transfusions (1-2 units) are less well understood. We evaluated the relationship between center-level organizational blood management practices and center-level variability in low volume transfusion rates. METHODS: All 33 nonfederal, Michigan cardiac surgical programs were surveyed about their blood management practices for isolated, nonemergent coronary bypass procedures, including: (1) presence and structure of a patient blood management program, (2) policies and procedures, and (3) audit and feedback practices. Practices were compared across low (N = 14, rate: 0.8%-10.1%) and high (N = 18, rate: 11.0%-26.3%) transfusion rate centers. RESULTS: Thirty-two (97.0%) of 33 institutions participated in this study. No statistical differences in organizational practices were identified between low- and high-rate groups, including: (1) the membership composition of patient blood management programs among those reporting having a blood management committee (P= .27-1.0), (2) the presence of available red blood cell units within the operating room (4 of 14 low-rate versus 2 of 18 high-rate centers report that they store no units per surgical case, P= .36), and (3) the frequency of internal benchmarking reporting about blood management audit and feedback practices (low rate: 8 of 14 versus high rate: 9 of 18; P= .43). CONCLUSIONS: We did not identify meaningful differences in organizational practices between low- and high-rate intraoperative transfusion centers. While a larger sample size may have been able to identify differences in organizational practices, efforts to reduce variation in 1- to 2-unit, intraoperative transfusions may benefit from evaluating other determinants, including organizational culture and provider transfusion practices.

Pneumolysin activates neutrophil extracellular trap formation.

The primary objective of the current study was to investigate the potential of the pneumococcal toxin, pneumolysin (Ply), to activate neutrophil extracellular trap (NET) formation in vitro. Isolated human blood neutrophils were exposed to recombinant Ply (5-20 ng ml(-1) ) for 30-90 min at 37°C and NET formation measured using the following procedures to detect extracellular DNA: (i) flow cytometry using Vybrant® DyeCycle™ Ruby; (ii) spectrofluorimetry using the fluorophore, Sytox(®) Orange (5 µM); and (iii) NanoDrop(®) technology. These procedures were complemented by fluorescence microscopy using 4', 6-diamino-2-phenylindole (DAPI) (nuclear stain) in combination with anti-citrullinated histone monoclonal antibodies to visualize nets. Exposure of neutrophils to Ply resulted in relatively rapid (detected within 30-60 min), statistically significant (P < 0·05) dose- and time-related increases in the release of cellular DNA impregnated with both citrullinated histone and myeloperoxidase. Microscopy revealed that NETosis appeared to be restricted to a subpopulation of neutrophils, the numbers of NET-forming cells in the control and Ply-treated systems (10 and 20 ng ml(-1) ) were 4·3 (4·2), 14.3 (9·9) and 16·5 (7·5), respectively (n = 4, P < 0·0001 for comparison of the control with both Ply-treated systems). Ply-induced NETosis occurred in the setting of retention of cell viability, and apparent lack of involvement of reactive oxygen species and Toll-like receptor 4. In conclusion, Ply induces vital NETosis in human neutrophils, a process which may either contribute to host defence or worsen disease severity, depending on the intensity of the inflammatory response during pneumococcal infection.

Blood Conservation-A Team Sport.

Cardiac surgery accounts for between 15% and 20% of all blood product utilization in the United States. A body of literature suggests that patients who are exposed to even small quantities of blood have an increased risk of morbidity and mortality, even after adjusting for pre-operative risk. Despite this body of literature supporting a restrictive blood management strategy, wide variability in transfusion rates exist across institutions. Recent blood management guidelines have shed light on a number of potentially promising blood management strategies, including acute normovolemic hemodilution (ANH) and retrograde autologous priming (RAP). We evaluated the literature concerning ANH and RAP, and the use of both techniques among centers participating in the Perfusion Measures and outcomes (PERForm) registry. We leveraged data concerning ANH and RAP among 10,203 patients undergoing isolated coronary artery bypass grafting (CABG) procedures from 2010 to 2014 at 27 medical centers. Meta-analyses have focused on the topic of ANH, with few studies focusing specifically on cardiac surgery. Two meta-analyses have been conducted to date on RAP, with many reporting higher intra-operative hematocrits and reduced transfusions. The rate of red blood cell transfusions in the setting of CABG surgery is 34.2%, although varied across institutions from 16.8% to 57.6%. Overall use of ANH was 11.6%, although the utilization varied from .0% to 75.7% across institutions. RAP use was 71.4%, although varied from .0% to 99.0% across institutions. A number of blood conservation strategies have been proposed, with varying levels of evidence from meta-analyses. This uncertainty has likely contributed to center-level differences in the utilization of these practices as evidenced by our multi-institutional database. Perfusion databases, including the PERForm registry, serve as a vehicle for perfusionist's to track their practice, and contribute to multidisciplinary team efforts aimed at assessing and improving the value of cardiac surgical care.

The Relationship between Intra-Operative Transfusions and Nadir Hematocrit on Post-Operative Outcomes after Cardiac Surgery.

Uncertainty exists regarding the optimal strategy for the management of anemia in the setting of cardiac surgery. We sought to improve our understanding of the role of intra-operative hematocrit (HCT) and transfusions on peri-operative outcomes following cardiac surgery. A total of 18,886 patients undergoing on-pump cardiac surgery were identified from a multi-institutional registry including surgical and perfusion data. Patients were divided into four groups based on their intra-operative nadir HCT (<21 or ≥21) and whether or not they received intra-operative red blood cell (+RBC or -RBC) transfusions. Outcomes were adjusted for the Society of Thoracic Surgeons predicted risk of mortality (PROM), pre-operative HCT, and medical center. Regardless of nadir HCT cohort, those who received a transfusion had higher PROM relative to patients who did not receive a transfusion. The mean PROM was significantly higher among those HCT ≥21 + RBC (5.3%) vs. HCT ≥ 21 - RBC (1.9%), p < .001. Similarly, the PROM was significantly higher among HCT <21 + RBC (5.1%) vs. those HCT <21 - RBC (3.1%), p < .001. Adjusted outcomes demonstrated an increased impact of RBC transfusions on adverse outcomes irrespective of nadir HCT including stroke (p < .001), renal failure (p < .001), prolonged ventilation (p < .001), and mortality (p < .001). This study demonstrates that transfusions have a more profound effect on post-operative cardiac surgery outcomes than anemia.

An autism-associated variant of Epac2 reveals a role for Ras/Epac2 signaling in controlling basal dendrite maintenance in mice.

The architecture of dendritic arbors determines circuit connectivity, receptive fields, and computational properties of neurons, and dendritic structure is impaired in several psychiatric disorders. While apical and basal dendritic compartments of pyramidal neurons are functionally specialized and differentially regulated, little is known about mechanisms that selectively maintain basal dendrites. Here we identified a role for the Ras/Epac2 pathway in maintaining basal dendrite complexity of cortical neurons. Epac2 is a guanine nucleotide exchange factor (GEF) for the Ras-like small GTPase Rap, and it is highly enriched in the adult mouse brain. We found that in vivo Epac2 knockdown in layer 2/3 cortical neurons via in utero electroporation reduced basal dendritic architecture, and that Epac2 knockdown in mature cortical neurons in vitro mimicked this effect. Overexpression of an Epac2 rare coding variant, found in human subjects diagnosed with autism, also impaired basal dendritic morphology. This mutation disrupted Epac2's interaction with Ras, and inhibition of Ras selectively interfered with basal dendrite maintenance. Finally, we observed that components of the Ras/Epac2/Rap pathway exhibited differential abundance in the basal versus apical dendritic compartments. These findings define a role for Epac2 in enabling crosstalk between Ras and Rap signaling in maintaining basal dendrite complexity, and exemplify how rare coding variants, in addition to their disease relevance, can provide insight into cellular mechanisms relevant for brain connectivity.

Acute phase proteins and stress hormone responses in patients with newly diagnosed active pulmonary tuberculosis.

INTRODUCTION: Despite the high burden of disease, there have been surprisingly few studies of the acute phase and plasma catecholamine/cortisol stress hormone responses in patients with active pulmonary tuberculosis. We wished to document acute phase reactant and stress hormone responses in patients with newly diagnosed, active pulmonary tuberculosis and to compare these responses to those of a group of surgical/medical cases with conditions other than tuberculosis. METHODS: This was a prospective study of consecutive patients with newly diagnosed pulmonary tuberculosis, admitted to a tertiary hospital in Johannesburg, South Africa, documenting demographic, clinical, routine laboratory, acute phase protein and stress hormone responses relative to those of the control group. RESULTS: TB patients had a higher body temperature and pulse rate, as well as a platelet counts, ferritin, CRP and dopamine levels, with a tendency to higher cortisol levels compared to the control group. Conversely, they had a lower BMI, haemoglobin, leucocyte count, MCV and epinephrine levels than the control group. CONCLUSIONS: Patients with active pulmonary tuberculosis were documented to mount an acute stress response which was more intense than that of a control group of patients with surgical/medical conditions other than tuberculosis.

Comparative evaluation of Schistosoma mansoni, Schistosoma intercalatum, and Schistosoma haematobium alkaline phosphatase antigenicity by the alkaline phosphatase immunoassay (APIA).

To know if alkaline phosphatase (AP) from schistosomes other than Schistosoma mansoni can be used as diagnostic marker for schistosomiasis in alkaline phosphatase immunocapture assay (APIA), we comparatively tested n-butanol extracts of adult worm membranes from a Venezuelan (JL) strain of S. mansoni (Ven/AWBE/Sm); a Cameroonian (EDEN) strain of Schistosoma intercalatum (Cam/AWBE/Si) and a Yemeni strain of Schistosoma haematobium (Yem/AWBE/Sh). APIA was evaluated with sera of patients from Venezuela, Senegal, and Gabon infected with S. mansoni, from Gabon infected with S. intercalatum or S. haematobium, from Chine infected with Schistosoma japonicum and from Cambodian patients infected with Schistosoma mekongi. Results indicate that 92.5% (37/40) of Venezuela sera, 75% (15/20) of Senegal sera, 39.5% (17/43) of S. haematobium sera, and 19.2% (5/26) S. intercalatum sera were APIA-positive with the Ven/AWBE/Sm preparation. APIA with the Cam/AWBE/Si preparation showed that 53.8% of S. intercalatum-positive sera had anti-AP antibodies, and 51.2% S. haematobium-positive sera cross-immunocapturing the S. intercalatum AP. APIA performed with Yem/AWBE/Sh showed that 55.8% S. haematobium sera were positive. Only two out of nine S. japonicum sera were APIA-positive with the Ven/AWBE/Sm and Cam/AWBE/Si, and no reaction was observed with Cambodian S. mekongi-positive sera. AP activity was shown to be present in all the schistosome species/strains studied. The use of APIA as a tool to explore the APs antigenicity and the presence of Schistosoma sp. infections through the detection of anti-Schistosoma sp. AP antibodies in a host, allowed us to demonstrate the antigenicity of APs of S. mansoni, S. intercalatum, and S. haematobium.

Fasciola hepatica in Cuba: compatibility of different isolates with two intermediate snail hosts, Galba cubensis and Pseudosuccinea columella.

In Cuba, only two lymnaeid snails, Galba cubensis and Pseudosuccinea columella, with different ecology and distribution patterns, are intermediate hosts for Fasciola hepatica. The compatibility of these two species as hosts was analysed through their rates of infection, the production of rediae and survivorship when exposed to F. hepatica miracidia. Ten populations of G. cubensis, eight of P. columella collected from various habitats and six isolates of F. hepatica sampled in slaughterhouses from different localities were tested. Our results clearly demonstrate that G. cubensis is a more compatible host for F. hepatica in Cuba when compared with P. columella. However, the role that P. columella may have in fascioliasis transmission under certain conditions should not be disregarded. Variation in infectivity among isolates of F. hepatica were also observed and may explain why some regions in Cuba are more commonly subjected to fascioliasis outbreaks.

Pro-inflammatory interactions of streptolysin O toxin with human neutrophils in vitro.

The recent global resurgence of severe infections caused by the Group A streptococcus (GAS) pathogen, Streptococcus pyogenes, has focused attention on this microbial pathogen, which produces an array of virulence factors, such as the pore-forming toxin, streptolysin O (SOT). Importantly, the interactions of SOT with human neutrophils (PMN), are not well understood. The current study was designed to investigate the effects of pretreatment of isolated human PMN with purified SOT on several pro-inflammatory activities, including generation of reactive oxygen species (ROS), degranulation (elastase release), influx of extracellular calcium (Ca2+) and release of extracellular DNA (NETosis), using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of PMN to SOT alone caused modest production of ROS and elastase release, while pretreatment with the toxin caused significant augmentation of chemoattractant (fMLP)-activated ROS generation and release of elastase by activated PMN. These effects of treatment of PMN with SOT were associated with both a marked and sustained elevation of cytosolic Ca2+concentrations and significant increases in the concentrations of extracellular DNA, indicative of NETosis. The current study has identified a potential role for SOT in augmenting the Ca2+-dependent pro-inflammatory interactions of PMN, which, if operative in a clinical setting, may contribute to hyper-activation of PMN and GAS-mediated tissue injury.

Thrombosis in the perforasome in idiopathic purpura fulminans with anti-protein S antibodies: Anatomical and clinical evidence to improve management.

Idiopathic purpura fulminans (IPF) is a rare and severe form of purpura fulminans caused by acquired protein S deficiency. It can lead to severe thrombotic complications, such as large skin necrosis and amputation. The lesions almost exclusively affect the lower limbs, and their distribution is similar among patients with IPF, unlike classical purpura fulminans lesions. Our hypothesis is that vascular structures called perforasomes may be involved in IPF, possibly caused by protein S deficiency. We analyzed all case reports and case series published in the literature that provided sufficient data for an anatomical study of limb injuries. For precise localization of areas of necrosis, we examined each case using descriptions and images to determine whether they overlapped with vascular territories that include perforasomes. We analyzed twelve cases from the literature and identified six vascular territories: the anterolateral, anteromedial, and posterior territories of the upper leg, as well as the anterolateral, anteromedial, and posterolateral territories of the lower leg. For each territory, we described the most probable vascular damage and the corresponding perforasome. IPF is a complex multifactorial disease in which a direct involvement of perforating arteries may be suspected and taken into account in the surgical of lesions.

Social, communication, and cortical structural impairments in Epac2-deficient mice.

Deficits in social and communication behaviors are common features of a number of neurodevelopmental disorders. However, the molecular and cellular substrates of these higher order brain functions are not well understood. Here we report that specific alterations in social and communication behaviors in mice occur as a result of loss of the EPAC2 gene, which encodes a protein kinase A-independent cAMP target. Epac2-deficient mice exhibited robust deficits in social interactions and ultrasonic vocalizations, but displayed normal olfaction, working and reference memory, motor abilities, anxiety, and repetitive behaviors. Epac2-deficient mice displayed abnormal columnar organization in the anterior cingulate cortex, a region implicated in social behavior in humans, but not in somatosensory cortex. In vivo two-photon imaging revealed reduced dendritic spine motility and density on cortical neurons in Epac2-deficient mice, indicating deficits at the synaptic level. Together, these findings provide novel insight into the molecular and cellular substrates of social and communication behavior.

AMPA receptor desensitization mutation results in severe developmental phenotypes and early postnatal lethality.

AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate) recep-tors desensitize rapidly and completely in the continued presence of their endogenous ligand glutamate; however, it is not clear what role AMPA receptor desensitization plays in the brain. We generated a knock-in mouse in which a single amino acid residue, which controls desensitization, was mutated in the GluA2 (GluR2) receptor subunit (GluA2(L483Y)). This mutation was homozygous lethal. However, mice carrying a single mutated allele, GluA2(L483Y/wt), survived past birth, but displayed severe and progressive neurological deficits including seizures and, ultimately, increased mortality. The expression of the AMPA receptor subunits GluA1 and GluA2 was decreased, whereas NMDA receptor protein expression was increased in GluA2(L483Y/wt) mice. Despite this, basal synaptic transmission and plasticity in the hippocampus were largely unaffected, suggesting that neurons preferentially target receptors to synapses to normalize synaptic weight. We found no gross neuroanatomical alterations in GluA2(L483Y/wt) mice. Moreover, there was no accumulation of AMPA receptor subunits in intracellular compartments, suggesting that folding and assembly of AMPA receptors are not affected by this mutation. Interestingly, EPSC paired pulse ratios in the CA1 were enhanced without a change in synaptic release probability, demonstrating that postsynaptic receptor properties can contribute to facilitation. The dramatic phenotype observed in this study by the introduction of a single amino acid change demonstrates an essential role in vivo for AMPA receptor desensitization.

Post-viral idiopathic purpura fulminans is associated with inherited thrombophilia and anti-cardiolipin antibodies.

Introduction: Idiopathic purpura fulminans (IPF) is a rare and severe coagulation disorder, associated with transient anti-protein S (anti-PS) antibodies in the context of post-viral infection such as varicella. Anti-protein S antibodies are frequently found in the context of varicella, in contrast with the rarity of IPF. Other factors such as anti-phospholipid antibodies (APL) and inherited thrombophilia may be associated with severe vascular complication. Method: This is an ancillary study of a French multicenter retrospective series and systematic review of literature. We analyzed patients who were tested for inherited thrombophilia, namely antithrombin, protein C, protein S deficiency; prothrombin gene G20210A polymorphism (FII:G20210A),Factor V R506Q polymorphism (FV:R506Q); and/or for APL (lupus anticoagulant (LA), anti-cardiolipin antibodies (ACL), or anti-beta 2-GPI antibodies (Aß2GP1). Results: Among the 25 patients tested for inherited thrombophilia, 7 (28%) had positive results. Three had FV R506Q, two FII:G20210A, one compound heterozygote FV:R506Q associated to FII:G20210A, and one protein C deficiency. APL testing was performed in 32 patients. It was positive in 19 patients (59%): 17 ACL (53%), 5 LA (16%), 4 Aß2GP1 (13%). The risk of severe complications was not associated with presence of inherited thrombophilia or APL presence, with RR: 0.8 [95% CI: 0.37-1.71], p = 1 and RR: 0.7 [95% CI: 0.33-1.51], p = 0.39, respectively. We found a high prevalence of inherited thrombophilia or APL in a population of patients with IPF. However, we do not find an association with the occurrence of severe vascular complications or venous thromboembolism.

Manganese promotes increased formation of hydrogen peroxide by activated human macrophages and neutrophils in vitro.

Although pro-inflammatory mechanisms have been implicated in the pathogenesis of manganese (Mn²âº)-related neurological and respiratory disorders, relatively little is known about the potential of this metal to interact pro-oxidatively with human phagocytes. The primary objective of the current study was to investigate the effects of Mn²âº as MnCl2 (0.5-100 µM) on the generation of the reactive oxygen species (ROS), superoxide, hydrogen peroxide (H2O2), and hypohalous acids by isolated human blood neutrophils and monocyte-derived macrophages following activation of these cells with the chemotactic tripeptide, FMLP (1 µM), or the phorbol ester, PMA (25 ng/mL). Generation of ROS was measured using the combination of oxygen consumption, lucigenin/luminol-enhanced chemiluminescence, spectrofluorimetric detection of oxidation of 2,7-dichlorodihydrofluorescein, radiometric assessment of myeloperoxidase (MPO)-mediated protein iodination, release of MPO by ELISA, and spectrophotometric measurement of nitrite formation. Treatment of activated neutrophils with either FMLP or PMA resulted in significantly decreased reactivity of superoxide in the setting of increased formation of H2O2 and MPO-mediated iodination, with no detectable effects on either oxygen consumption or MPO release. Similar effects of the metal with respect to superoxide reactivity and H2O2 formation were observed with activated macrophages, while generation of NO was unaffected. Taken together with the findings of experiments using cell-free ROS-generating systems, these observations are compatible with a mechanism whereby Mn²âº, by acting as a superoxide dismutase mimetic, increases the formation of H2O2 by activated phagocytes. If operative in vivo, this mechanism may contribute to the toxicity of Mn²âº.