Prevalence and correlates of diphtheria toxoid antibodies in children and adults in Israel

A seroepidemiological study was performed to evaluate immunity to diphtheria and to determine the correlates of diphtheria toxoid antibody levels among children and adults in Israel. In total, 3,185 sera from an age-stratified sample of children and adults, obtained in 2000-2001, were tested for diphtheria toxoid antibodies by an in-house double-antigen ELISA. A level of or=0.1 IU/mL (full protection or seropositivity). Seronegativity increased significantly in subjects aged >50 years, reaching levels of 9.7%, 12.6% and 18.9% in the groups aged 50-54, 55-59 and >60 years, respectively (p 0.001), with rates of basic immunity following a similar pattern. Subjects born abroad had higher seronegativity rates than those born in Israel (7.7% vs. 4.9%; p 0.019). No difference in diphtheria toxoid antibody levels was found according to other demographical variables, such as gender, Jewish or Arab ethnicity, urban or rural settlements, and the subjects' place of residence. The level of immunity to diphtheria among children and adults in Israel was satisfactory, with the exception of individuals aged >50 years. The risk of diphtheria outbreaks is low, but sporadic cases may occur among individuals lacking basic immunity against the disease.     

Initial concentration of Staphylococcus epidermidis in simulated pediatric blood cultures correlates with time to positive results with the automated, continuously monitored BACTEC blood culture system

The relationship of initial concentration of Staphylococcus epidermidis in blood cultures and time to positivity (TTP) in an automated, continuously monitored blood culture system was assessed. Blood and 1 to 1,000 CFU of S. epidermidis per ml in stationary or exponential phase were inoculated in BACTEC Pediatric Plus F bottles and incubated. The TTP was inversely proportional to the initial inoculated concentration. Blood culture bottles with initial bacterial densities of <10 CFU/ml had a TTP of >20 h (upper limit of 95% prediction interval, 20.7 h) and bottles with initial bacterial densities of > or =50 CFU/ml had a TTP of < or =15 h (lower limit of 95% prediction interval, 13.4 h).     

A miniature and mobile intermittent pneumatic compression device for the prevention of deep-vein thrombosis after joint replacement

The WizAir-DVT is a miniature, lightweight (690 g), battery-operated and mobile intermittent pneumatic compression device (ICD), which enables continuous intraoperative use and immediate patient mobilization postoperatively. We compared its efficacy with a commonly used ICD, the Kendall SCD. Peak femoral vein flow velocity was measured in 20 apparently healthy volunteers at rest and with each device: we found no significant differences between them. A second prospective, randomized, clinical trial was used to compare the efficiency of the device in preventing deep venous thrombosis (DVT) after joint replacement in 50 patients (n=25/group). None developed DVT. Doppler ultrasonography revealed no significant differences. The WizAir-DVT antithrombotic compression device is as safe and effective as the Kendall SCD.     

Allogeneic stem cell transplantation for patients with chronic myeloid leukemia: Risk stratified approach with a long-term follow-up

The use of allogeneic stem cell transplantation (SCT) for chronic myeloid leukemia (CML) was almost abandoned in recent years for very effective targeted therapy with tyrosine kinase inhibitors (TKIs). However, approximately one third of patients still need another treatment including SCT. 38 consecutive CML patients were treated (most in preimatinib era) with allogeneic SCT, using partial T cell depletion (TCD) and preemptive donor lymphocyte infusion (DLI), without post‐transplant graft‐versus‐host disease (GvHD) prophylaxis. Conditioning included busulfan, cyclophosphamide, antithymocytic globulin, and fludarabine followed by donor stem cell transfusion. With a median follow up of 90.5 months (1–134), 32 patients are alive. 97% engrafted. 5‐year leukemia free survival (LFS) and overall survival (OS) were 78.95% and 84.2%, respectively. All patients are in major molecular remission and 78% in complete molecular remission. Transplant‐related mortality (TRM) was 13%. Twenty‐four patients received DLI for residual disease. Acute GvHD, mostly Grades I‐II, occurred in 18% of patients post‐transplant and in 24% of patients receiving DLI. In conclusion, the risk‐adapted approach using only partial TCD and preemptive escalated dose of DLI precluded the need for immunosuppressive medications and reduced the risk of significant GvHD without compromising engraftment and long‐term disease control. Am. J. Hematol. 2012. © 2012 Wiley Periodicals, Inc.     

Mapping the diatom redox-sensitive proteome provides insight into response to nitrogen stress in the marine environment

Diatoms are ubiquitous marine photosynthetic eukaryotes responsible for approximately 20% of global photosynthesis. Little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a quantitative mass spectrometry-based approach to elucidate the redox-sensitive signaling network (redoxome) mediating the response of diatoms to oxidative stress. We quantified the degree of oxidation of 3,845 cysteines in the Phaeodactylum tricornutum proteome and identified approximately 300 redox-sensitive proteins. Intriguingly, we found redox-sensitive thiols in numerous enzymes composing the nitrogen assimilation pathway and the recently discovered diatom urea cycle. In agreement with this finding, the flux from nitrate into glutamine and glutamate, measured by the incorporation of ¹⁵N, was strongly inhibited under oxidative stress conditions. Furthermore, by targeting the redox-sensitive GFP sensor to various subcellular localizations, we mapped organelle-specific oxidation patterns in response to variations in nitrogen quota and quality. We propose that redox regulation of nitrogen metabolism allows rapid metabolic plasticity to ensure cellular homeostasis, and thus is essential for the ecological success of diatoms in the marine ecosystem.Aerobic organisms produce reactive oxygen species (ROS) as a byproduct of oxygen-based metabolic pathways, such as photosynthesis, photorespiration, and oxidative phosphorylation (1). Perturbations in oxygenic metabolism under various stress conditions can induce oxidative stress from overproduction of ROS (2, 3). Because ROS are highly reactive forms of oxygenic metabolites, critical mechanisms for ROS detoxification have evolved consisting of ROS-scavenging enzymes and small molecules, including glutathione (GSH) (4). As the most abundant low molecular weight thiol antioxidant, GSH has critical roles in maintaining a proper cellular thiol–disulfide balance and in detoxifying H₂O₂ via the ascorbate–GSH cycle (5).Although classically ROS were considered toxic metabolic byproducts that ultimately lead to cell death, it is now recognized that ROS act as central secondary messengers involved in compartmentalized signaling networks (1, 6–8). Modulation of various cell processes by ROS signaling is mediated largely by posttranslational thiol oxidation, whereby their physical structure and biochemical activity are modified upon oxidation (9). Thus, the redox states of these proteins possess crucial information needed for cell acclimation to stress conditions (10, 11). The emergence of advanced redox proteomic approaches, such as the OxICAT method (12), has created new opportunities to identify redox-sensitive proteins (e.g., redoxome) on the system level and to quantify their precise level of oxidation on exposure to environmental stress conditions.Marine photosynthetic microorganisms (phytoplankton) are the basis of marine food webs. Despite the fact that their biomass represents only approximately 0.2% of the photosynthetic biomass on earth, they are responsible for nearly 50% of the annual global carbon-based photosynthesis and greatly influence the global biogeochemical carbon cycle (13). This high ratio of productivity to biomass, reflected in high turnover rates, makes phytoplankton highly responsive to climate change. Phytoplankton can grow rapidly and form massive blooms that stretch over hundreds of kilometers in the oceans and are regulated by such environmental factors as nutrient availability and biotic interactions with grazers and viruses.Diatoms are a highly diverse clade of phytoplankton, responsible for roughly 20% of global primary productivity (14). Consequently, diatoms play a central role in the biogeochemical cycling of important nutrients, including carbon, nitrogen, and silica, which constitute part of their ornate cell wall. As members of the eukaryotic group known as stramenopiles (or heterokonts), diatoms are derived from a secondary endosymbiotic event involving red and green algae engulfed within an ancestral protest (15).The unique multilineage content of diatom genomes reveals a melting pot of biochemical characteristics that resemble bacterial, plant, and animal traits, including the integration of a complete urea cycle, fatty acid oxidation in the mitochondria, and plant C4-like related pathways (16, 17). During bloom succession, phytoplankton cells are subjected to diverse environmental stress conditions that lead to ROS production, such as allelopathic interactions (18), CO₂ availability (19, 20), UV exposure (21), iron limitation (22), and viral infection (23). Recently reported evidence suggests that diatoms possess a surveillance system based on the induction of ROS that have been implicated in response to various environmental stresses (22, 24). Nevertheless, very little is known about cell signaling processes in marine phytoplankton and their potential role in acclimation to rapid fluctuations in the chemophysical gradients in the marine environment (25).Using a mass spectrometry-based approach, we examined the diatom redoxome and quantified its degree of oxidation under oxidative stress conditions. The wealth of recently identified redox-sensitive proteins participating in various cellular functions suggests a fundamental role of redox regulation in diatom biology. We mapped the redox-sensitive enzymes into a metabolic network and evaluated their role in the adjustment of metabolic flux under variable environmental conditions. We further explored the redox sensitivity of the primary nitrogen-assimilating pathway and demonstrated the role of compartmentalized redox regulation in cells under nitrogen stress conditions using a redox-sensitive GFP sensor targeted to specific subcellular localizations.     

Transthoracic parametric Doppler for bedside diagnosis of pulmonary embolism: A pilot study

Transthoracic parametric Doppler (TPD), unlike conventional ultrasonography, measures signals originating from movements of pulmonary blood vessel walls. In this pilot study, we tested TPD in 15 patients diagnosed with pulmonary embolism on computed tomography pulmonary angiography. Results were mapped to the upper, middle, and lower thirds of the right lung. In the lower third, TPD yielded 100% specificity and positive predictive value for acute pulmonary embolism. If validated in a larger series, this rapid bedside technique might obviate the need for computed tomography in specific cases. This could be advantageous in patients who are unstable, in intensive care, or have allergies to iodinated contrast material.     

Targeting glycosylated antigens on cancer cells using siglec-7/9-based CAR T-cells

Chimeric antigen receptor (CAR) T-cells treatment demonstrate the increasing and powerful potential of immunotherapeutic strategies, as seen mainly for hematological malignancies. Still, efficient CAR-T cell approaches for the treatment of a broader spectrum of tumors are needed. It has been shown that cancer cells can implement strategies to evade immune response that include the expression of inhibitory ligands, such as hypersialylated proteins (sialoglycans) on their surface. These may be recognized by sialic acid-binding immunoglobulin-type lectins (siglecs) which are surface receptors found primarily on immune cells. In this regard, siglec-7 and -9 are found on immune cells, such as natural killer cells, T-cells, and dendritic cells and they can promote immune suppression when binding to sialic acids expressed on target cells. In the present study, we hypothesized that it is possible to use genetically engineered T-cells expressing siglec-based CARs, enabling them to recognize and eliminate tumor cells, in a non-histocompatibility complex molecule restricted way. Thus, we genetically modified human T-cells with different chimeric receptors based on the exodomain of human siglec-7 and -9 molecules and selected optimal receptors. We then assessed their antitumor activity in vitro demonstrating the recognition of cell lines from different histologies. These results were confirmed in a tumor xenograft model exemplifying the potential of the present approach. Overall, this study demonstrates the benefit of targeting cancer-associated glycosylation patterns using CAR based on native immune receptors and expressed in human primary T-cells.