T. brucei cathepsin-L increases arrhythmogenic sarcoplasmic reticulum-mediated calcium release in rat cardiomyocytes

Aims: African trypanosomiasis, caused by Trypanosoma brucei species, leads to both neurological and cardiac dysfunction and can be fatal if untreated. While the neurological-related pathogenesis is well studied, the cardiac pathogenesis remains unknown. The current study exposed isolated ventricular cardiomyocytes and adult rat hearts to T. brucei to test whether trypanosomes can alter cardiac function independent of a systemic inflammatory/immune response. Methods and results: Using confocal imaging, T. brucei and T. brucei culture media (supernatant) caused an increased frequency of arrhythmogenic spontaneous diastolic sarcoplasmic reticulum (SR)-mediated Ca2+ release (Ca2+ waves) in isolated adult rat ventricular cardiomyocytes. Studies utilising inhibitors, recombinant protein and RNAi all demonstrated that this altered SR function was due to T. brucei cathepsin-L (TbCatL). Separate experiments revealed that TbCatL induced a 10–15% increase of SERCA activity but reduced SR Ca2+ content, suggesting a concomitant increased SR-mediated Ca2+ leak. This conclusion was supported by data demonstrating that TbCatL increased Ca2+ wave frequency. These effects were abolished by autocamtide-2-related inhibitory peptide, highlighting a role for CaMKII in the TbCatL action on SR function. Isolated Langendorff perfused whole heart experiments confirmed that supernatant caused an increased number of arrhythmic events. Conclusion: These data demonstrate for the first time that African trypanosomes alter cardiac function independent of a systemic immune response, via a mechanism involving extracellular cathepsin-L-mediated changes in SR function

Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (SAGE) I: Overview and Initial Results

We are performing a uniform and unbiased, ~7x7 degrees imaging survey of the Large Magellanic Cloud (LMC), using the IRAC and MIPS instruments on board the Spitzer Space Telescope in order to survey the agents of a galaxy's evolution (SAGE), the interstellar medium (ISM) and stars in the LMC. The detection of diffuse ISM with column densities >1.2x10^21 H cm^-2 permits detailed studies of dust processes in the ISM. SAGE's point source sensitivity enables a complete census of newly formed stars with masses >3 solar masses that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass loss rates >1x10^-8 solar masses per year will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by three months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are non-proprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data with a special focus on the N79 and N83 region. The SAGE epoch 1 point source catalog has ~4 million sources. The point source counts are highest for the IRAC 3.6 microns band and decrease dramatically towards longer wavelengths consistent with the fact that stars dominate the point source catalogs and that the dusty objects, e.g. young stellar objects and dusty evolved stars that detected at the longer wavelengths, are rare in comparison. We outline a strategy for identifying foreground MW stars, that may comprise as much as 18% of the source list, and background galaxies, that may comprise ~12% of the source list.Comment: Accepted by the Astronomical Journa

Spitzer survey of the Large Magellanic Cloud, surveying the agents of a galaxy's evolution (SAGE). IV. Dust properties in the interstellar medium

The goal of this paper is to present the results of a preliminary analysis of the extended infrared (IR) emission by dust in the interstellar medium (ISM) of the Large Magellanic Cloud (LMC). We combine Spitzer Surveying the Agents of Galaxy Evolution (SAGE) and Infrared Astronomical Satellite (IRAS) data and correlate the infrared emission with gas tracers of H I, CO, and Hα. We present a global analysis of the infrared emission as well as detailed modeling of the spectral energy distribution (SED) of a few selected regions. Extended emission by dust associated with the neutral, molecular, and diffuse ionized phases of the ISM is detected at all IR bands from 3.6 μm to 160 μm. The relative abundance of the various dust species appears quite similar to that in the Milky Way (MW) in all the regions we have modeled. We construct maps of the temperature of large dust grains. The temperature map shows variations in the range 12.1-34.7 K, with a systematic gradient from the inner to outer regions, tracing the general distribution of massive stars and individual H II regions as well as showing warmer dust in the stellar bar. This map is used to derive the far-infrared (FIR) optical depth of large dust grains. We find two main departures in the LMC with respect to expectations based on the MW: (1) excess mid-infrared (MIR) emission near 70 μm, referred to as the 70 μm excess, and (2) departures from linear correlation between the FIR optical depth and the gas column density, which we refer to as FIR excess emission. The 70 μm excess increases gradually from the MW to the LMC to the Small Magellanic Cloud (SMC), suggesting evolution with decreasing metallicity. The excess is associated with the neutral and diffuse ionized gas, with the strongest excess region located in a loop structure next to 30 Dor. We show that the 70 μm excess can be explained by a modification of the size distribution of very small grains with respect to that in the MW, and a corresponding mass increase of ≃13% of the total dust mass in selected regions. The most likely explanation is that the 70 μm excess is due to the production of large very small grains (VSG) through erosion of larger grains in the diffuse medium. This FIR excess could be due to intrinsic variations of the dust/gas ratio, which would then vary from 4.6 to 2.3 times lower than the MW values across the LMC, but X_(CO) values derived from the IR emission would then be about three times lower than those derived from the Virial analysis of the CO data. We also investigate the possibility that the FIR excess is associated with an additional gas component undetected in the available gas tracers. Assuming a constant dust abundance in all ISM phases, the additional gas component would have twice the known H I mass. We show that it is plausible that the FIR excess is due to cold atomic gas that is optically thick in the 21 cm line, while the contribution by a pure H_2 phase with no CO emission remains a possible explanation

Delirium is associated with an increased morbidity and in-hospital mortality in cancer patients : results from a prospective cohort study

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Objective: Delirium is a frequent complication in advanced cancer patients, among whom it is frequently underdiagnosed and inadequately treated. To date, evidence on risk factors and the prognostic impact of delirium on outcomes remains sparse in this patient population. Method: In this prospective observational cohort study at a single tertiary-care center, 1,350 cancer patients were enrolled. Simple and multiple logistic regression models were utilized to identify associations between predisposing and precipitating factors and delirium. Cox proportional-hazards models were used to estimate the effect of delirium on death rate. Results: In our patient cohort, the prevalence of delirium was 34.3%. Delirium was associated inter alia with prolonged hospitalization, a doubling of care requirements, increased healthcare costs, increased need for institutionalization (OR 3.22), and increased mortality (OR 8.78). Predisposing factors for delirium were impaired activity (OR 10.82), frailty (OR 4.75); hearing (OR 2.23) and visual impairment (OR 1.89), chronic pneumonitis (OR 2.62), hypertension (OR 1.46), and renal insufficiency (OR 1.82). Precipitating factors were acute renal failure (OR 7.50), pressure sores (OR 3.78), pain (OR 2.86), and cystitis (OR 1.32). On multivariate Cox regression, delirium increased the mortality risk sixfold (HR 5.66). Age ≥ 65 years and comorbidities further doubled the mortality risk of delirious patients (HR 1.77; HR 2.05). Significance of results: Delirium is common in cancer patients and associated with increased morbidity and mortality. Systematically categorizing predisposing and precipitating factors might yield new strategies for preventing and managing delirium in cancer patients

Probiotic modulation of symbiotic gut microbial–host metabolic interactions in a humanized microbiome mouse model

The transgenomic metabolic effects of exposure to either Lactobacillus paracasei or Lactobacillus rhamnosus probiotics have been measured and mapped in humanized extended genome mice (germ-free mice colonized with human baby flora). Statistical analysis of the compartmental fluctuations in diverse metabolic compartments, including biofluids, tissue and cecal short-chain fatty acids (SCFAs) in relation to microbial population modulation generated a novel top-down systems biology view of the host response to probiotic intervention. Probiotic exposure exerted microbiome modification and resulted in altered hepatic lipid metabolism coupled with lowered plasma lipoprotein levels and apparent stimulated glycolysis. Probiotic treatments also altered a diverse range of pathways outcomes, including amino-acid metabolism, methylamines and SCFAs. The novel application of hierarchical-principal component analysis allowed visualization of multicompartmental transgenomic metabolic interactions that could also be resolved at the compartment and pathway level. These integrated system investigations demonstrate the potential of metabolic profiling as a top-down systems biology driver for investigating the mechanistic basis of probiotic action and the therapeutic surveillance of the gut microbial activity related to dietary supplementation of probiotics

Protocadherin-18 Is a Novel Differentiation Marker and an Inhibitory Signaling Receptor for CD8+ Effector Memory T Cells

CD8+ tumor infiltrating T cells (TIL) lack effector-phase functions due to defective proximal TCR-mediated signaling previously shown to result from inactivation of p56lck kinase. We identify a novel interacting partner for p56lck in nonlytic TIL, Protocadherin-18 (‘pcdh18’), and show that pcdh18 is transcribed upon in vitro or in vivo activation of all CD8+ central memory T cells (CD44+CD62LhiCD127+) coincident with conversion into effector memory cells (CD44+CD62LloCD127+). Expression of pcdh18 in primary CD8+ effector cells induces the phenotype of nonlytic TIL: defective proximal TCR signaling, cytokine secretion, and cytolysis, and enhanced AICD. pcdh18 contains a motif (centered at Y842) shared with src kinases (QGQYQP) that is required for the inhibitory phenotype. Thus, pcdh18 is a novel activation marker of CD8+ memory T cells that can function as an inhibitory signaling receptor and restrict the effector phase

Combination of ciprofloxacin/celecoxib as a novel therapeutic strategy for ALS

Objective: This study aimed to evaluate the safety and tolerability of a fixed-dose co-formulation of ciprofloxacin and celecoxib (PrimeC) in patients with amyotrophic lateral sclerosis (ALS), and to examine its effects on disease progression and ALS-related biomarkers. Methods: In this proof of concept, open-label, phase IIa study of PrimeC in 15 patients with ALS, participants were administered PrimeC thrice daily for 12 months. The primary endpoints were safety and tolerability. Exploratory endpoints included disease progression outcomes such as forced vital capacity, revised ALS functional rating scale, and effect on algorithm-predicted survival. In addition, indications of a biological effect were assessed by selected biomarker analyses, including TDP-43 and LC3 levels in neuron-derived exosomes (NDEs), and serum neurofilaments. Results: Four participants experienced adverse events (AEs) related to the study drug. None of these AEs were unexpected, and most were mild or moderate (69%). Additionally, no serious AEs were related to the study drug. One participant tested positive for COVID-19 and recovered without complications, and no other abnormal laboratory investigations were found. Participants’ survival compared to their predictions showed no safety concerns. Biomarker analyses demonstrated significant changes associated with PrimeC in neural-derived exosomal TDP-43 levels and levels of LC3, a key autophagy marker. Interpretation: This study supports the safety and tolerability of PrimeC in ALS. Biomarker analyses suggest early evidence of a biological effect. A placebo-controlled trial is required to disentangle the biomarker results from natural progression and to evaluate the efficacy of PrimeC for the treatment of ALS. Summary for social media if published Twitter handles: @NeurosenseT, @ShiranZimri •What is the current knowledge on the topic? ALS is a severe neurodegenerative disease, causing death within 2–5 years from diagnosis. To date there is no effective treatment to halt or significantly delay disease progression. •What question did this study address? This study assessed the safety, tolerability and exploratory efficacy of PrimeC, a fixed dose co-formulation of ciprofloxacin and celecoxib in the ALS population. •What does this study add to our knowledge? This study supports the safety and tolerability of PrimeC in ALS, and exploratory biomarker analyses suggest early insight for disease related-alteration. •How might this potentially impact the practice of neurology? These results set the stage for a larger, placebo-controlled study to examine the efficacy of PrimeC, with the potential to become a new drug candidate for ALS

Association between intracranial vessel calcifications, structural brain damage, and cognitive impairment after minor strokes: a prospective study

BackgroundVascular calcifications are a hallmark of atherosclerosis, and in the coronary arteries are routinely used as a prognostic marker. Calcifications of intracranial vessels (ICC) are frequently observed on non-contrast CT (NCCT) and their effect on post-stroke cognitive impairment (PSCI) remains unclear. Our aim was to explore the association of ICC with prospective long-term cognitive function and advanced MRI-measures in a large prospective cohort of cognitively intact mild stroke survivors.MethodsData from the Tel-Aviv brain acute stroke cohort (TABASCO) study [ClinicalTrials.gov #NCT01926691] were analyzed. This prospective cohort study (n = 575) aimed to identify predictors of PSCI, in cognitively intact mild stroke survivors. A quantitative assessment of the intracranial calcium content – The ICC score (ICCS) was calculated semi-automatically on NCCT using a validated calcium quantification application. Participants underwent a 3 T-MRI and prospective comprehensive cognitive clinical and laboratory assessments at enrollment, 6, 12, and 24-months.ResultsData were available for 531 participants (67.4 years, 59.5% males). The incidence of PSCI at two-years doubled in the high ICCS group (26% vs. 13.7%, p < 0.001). The high ICCS group had significantly greater small-vessel-disease (SVD) tissue changes and reduced microstructural-integrity assessed by Diffusion-Tensor-Imaging (DTI) maps (p < 0.05 for all). In multivariate analysis, a higher ICCS was independently associated with brain atrophy manifested by lower normalized white and gray matter, hippocampal and thalamic volumes (β = −0.178, β = −0.2, β = −0.137, β = −0.157; p < 0.05) and independently predicted PSCI (OR 1.83, 95%CI 1.01–3.35).ConclusionOur findings suggest that the ICCS, which is a simple and readily available imaging marker on NCCT, is associated with brain atrophy, microstructural damage, the extent of SVD, and may predict PSCI. This finding has implications for identifying individuals at risk for PSCI and implementing targeted interventions to mitigate this risk