Sunitinib mediates mitochondrial ROS production in adult rat cardiac fibroblasts via CaMKII oxidation

Ca2+/calmodulin dependent protein kinase II (CaMKII) is a central mediator of Ca2+-induced signalling in the heart and regulates both normal cardiac physiology and pathology. Sunitinib malate is an oral Type I tyrosine kinase inhibitor (TKI) known to inhibit more than 50 kinases, with anti-angiogenic and anti-proliferative effects affiliated with off-target cardiotoxicity. Previous work has shown that chronic sunitinib treatment significantly increases CaMKII expression and activity and this correlates with significant cardiac dysfunction in vivo.1 Mitochondrial dysfunction, mediated by increased mitochondrial Ca2+ and resultant mitochondrial ROS production, has been proposed as an underlying mechanism for TKI-induced cardiotoxicity in cardiomyocytes.2 However, little is known of how TKIs may affect the non-contractile cells of the heart. Here, we have investigated whether sunitinib treatment increases mitochondrial ROS production in cardiac fibroblasts (CF) and whether CaMKII may play a role in this potential cardiotoxic mechanis

CaMKIIδ interacts directly with IKKβ and modulates NF-κB signalling in adult cardiac fibroblasts

Calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) acts as a molecular switch regulating cardiovascular Ca2+ handling and contractility in health and disease. Activation of CaMKIIδ is also known to regulate cardiovascular inflammation and is reported to be required for pro-inflammatory NF-κB signalling. In this study the aim was to characterise how CaMKIIδ interacts with and modulates NF-κB signalling and whether this interaction exists in non-contractile cells of the heart. Recombinant or purified CaMKIIδ and the individual inhibitory -κB kinase (IKK) proteins of the NF-κB signalling pathway were used in autoradiography and Surface Plasmon Resonance (SPR) to explore potential interactions between both components. Primary adult rat cardiac fibroblasts were then used to study the effects of selective CaMKII inhibition on pharmacologically-induced NF-κB activation as well as interaction between CaMKII and specific IKK isoforms in a cardiac cellular setting. Autoradiography analysis suggested that CaMKIIδ phosphorylated IKKβ but not IKKα. SPR analysis further supported a direct interaction between CaMKIIδ and IKKβ but not between CaMKIIδ and IKKα or IKKγ. CaMKIIδ regulation of IκΒα degradation was explored in adult cardiac fibroblasts exposed to pharmacological stimulation. Cells were stimulated with agonist in the presence or absence of a CaMKII inhibitor, autocamtide inhibitory peptide (AIP). Selective inhibition of CaMKII resulted in reduced NF-κB activation, as measured by agonist-stimulated IκBα degradation. Importantly, and in agreement with the recombinant protein work, an interaction between CaMKII and IKKβ was evident following Proximity Ligation Assays in adult cardiac fibroblasts. This study provides new evidence supporting direct interaction between CaMKIIδ and IKKβ in pro-inflammatory signalling in cardiac fibroblasts and could represent a feature that may be exploited for therapeutic benefit

Illusory perceptions of space and time preserve cross-saccadic perceptual continuity

When voluntary saccadic eye movements are made to a silently ticking clock, observers sometimes think that the second hand takes longer than normal to move to its next position. For a short period, the clock appears to have stopped (chronostasis). Here we show that the illusion occurs because the brain extends the percept of the saccadic target backwards in time to just before the onset of the saccade. This occurs every time we move the eyes but it is only perceived when an external time reference alerts us to the phenomenon. The illusion does not seem to depend on the shift of spatial attention that accompanies the saccade. However, if the target is moved unpredictably during the saccade, breaking perception of the target's spatial continuity, then the illusion disappears. We suggest that temporal extension of the target's percept is one of the mechanisms that 'fill in' the perceptual 'gap' during saccadic suppression. The effect is critically linked to perceptual mechanisms that identify a target's spatial stability

The Epidemiology and Clinical Spectrum of Melioidosis: 540 Cases from the 20 Year Darwin Prospective Study

Melioidosis is an occupationally and recreationally acquired infection important in Southeast Asia and northern Australia. Recently cases have been reported from more diverse locations globally. The responsible bacterium, Burkholderia pseudomallei, is considered a potential biothreat agent. Risk factors predisposing to melioidosis are well recognised, most notably diabetes. The Darwin prospective melioidosis study has identified 540 cases of melioidosis over 20 years and analysis of the epidemiology and clinical findings provides important new insights into this disease. Risk factors identified in addition to diabetes, hazardous alcohol use and chronic renal disease include chronic lung disease, malignancies, rheumatic heart disease, cardiac failure and age ≥50 years. Half of patients presented with pneumonia and septic shock was common (21%). The decrease in mortality from 30% in the first 5 years of the study to 9% in the last five years is attributed to earlier diagnosis and improvements in intensive care management. Of the 77 fatal cases (14%), all had known risk factors for melioidosis. This supports the most important conclusion of the study, which is that melioidosis is very unlikely to kill a healthy person, provided the infection is diagnosed early and resources are available to provide appropriate antibiotics and critical care where required

Development of the chronic obstructive pulmonary disease morning symptom diary (COPD-MSD).

BACKGROUND: The morning tends to be the most difficult time of day for many patients with chronic obstructive pulmonary disease (COPD) when symptoms can limit one's ability to perform even simple activities. Morning symptoms have been linked to higher levels of work absenteeism, thereby increasing the already substantial economic burden associated with COPD. A validated patient-reported outcome (PRO) instrument designed to capture morning symptoms will allow for a more comprehensive approach to the evaluation of treatment benefit in COPD clinical trials. METHODS: A qualitative interview study was conducted among a sample of symptomatic adults with COPD. Concept elicitation interviews (n = 35) were conducted to identify COPD morning symptoms, followed by cognitive interviews (n = 21) to ensure patient comprehension of the items, instructions and response options of the draft COPD Morning Symptom Diary (COPD-MSD). All interview transcript data were coded using ATLAS.ti software for content analysis. RESULTS: Mean age of the concept elicitation and cognitive interview sample was 65.0 years (±7.5) and 62.3 years (±8.3), respectively. The study sample represented the full range of COPD severity (Global Initiative for Chronic Lung Disease [GOLD] classifications I-IV) and included a mix of racial backgrounds, employment status and educational achievement. During the concept elicitation interviews, the three most frequently reported morning symptoms were shortness of breath (n = 35/35; 100 %), phlegm/mucus (n = 31/35; 88.6 %), and cough (n = 30/35; 85.7 %). A group of clinical and instrument development experts convened to review the concept elicitation data and develop the initial 32-item draft COPD-MSD. Cognitive interviews indicated subjects found the draft COPD-MSD to be comprehensive, clear, and easy to understand. The COPD-MSD underwent minor editorial revisions and streamlining based on cognitive interviews and input from the experts to yield the final 19-item daily diary. CONCLUSIONS: This study supports the content validity of the new COPD-MSD and positions the diary for quantitative psychometric testing

Accuracy of Doppler-Echocardiographic Mean Pulmonary Artery Pressure for Diagnosis of Pulmonary Hypertension

Background: The validity of Doppler echocardiographic (DE) measurement of systolic pulmonary artery pressure (sPAP) has been questioned. Recent studies suggest that mean pulmonary artery pressure (mPAP) might reflect more accurately the invasive pressures. Methodology/Principal Findings: 241 patients were prospectively studied to evaluate the diagnostic accuracy of mPAP for the diagnosis of PH. Right heart catheterization (RHC) and DE were performed in 164 patients mainly for preoperative evaluation of heart valve dysfunction. The correlation between DE and RHC was better when mPAP (r = 0.93) and not sPAP (r = 0.81) was assessed. Bland-Altman analysis revealed a smaller variation of mPAP than sPAP. The following ROC analysis identified that a mPAP$25.5 mmHg is useful for the diagnosis of PH. This value was validated in an independent cohort of patients (n = 50) with the suspicion of chronic-thromboembolic pulmonary hypertension. The calculated diagnostic accuracy was 98%, based on excellent sensitivity of 98 % and specificity of 100%. The corresponding positive and negative predictive values were 100%, respectively 88%. Conclusion: mPAP has been found to be highly accurate for the initial diagnosis of PH. A cut-off value of 25.5 mmHg might be helpful to avoid unnecessary RHC and select patients in whom RHC might be beneficial

Temporal Stability and the Effects of Training on Saccade Latency in “Express Saccade Makers”

The temporal stability of saccade latency, and the effects of training, particularly in “express saccade makers” (ESMs), has received little attention. ESMs are healthy, naïve, adults, who persist in executing very many low latency “express saccades” (ES; saccades with latency of 80 ms to 130 ms), in conditions designed to suppress such responses. We investigated the stability of ES production (%ES) in 59 ESM and 54 non-ESM participants in overlap tasks. Within a single session, the intraclass correlation coefficient (ICC) for %ES in two runs of 200 trials was 0.97 (p30% of saccades over the two runs were ES, were classified as ESMs. For 60 participants tested over two sessions 12 weeks apart, and 30 participants tested in three sessions over approximately six months, the ICC for %ES was uniformly high (0.95, p<0.001 and 0.97, p<0.001 respectively) and participants behaved consistently with their initial classification. Fourteen participants (7 ESMs) were then exposed to training consisting of either gap or overlap tasks. Training increased %ES in both groups. However, when tested in overlap tasks, it was not sufficient to transform Normal participants into ESMs. We conclude that the pattern of saccade behaviour exhibited by ESMs constitutes a stable and distinct oculomotor phenotype

The labour supply effect of Education Maintenance Allowance and its implications for parental altruism

Education Maintenance Allowance (EMA) was a UK government cash transfer paid directly to children aged 16–18, in the first 2 years of post-compulsory full-time education. This paper uses the labour supply effect of EMA to infer the magnitude of the transfer response made by the parent, and so test for the presence of an ‘effectively altruistic’ head-of-household, who redistributes resources among household members so as to maximise overall welfare. Using data from the Longitudinal Study of Young People in England, an EMA payment of £30 per week is found to reduce teenagers’ labour supply by 3 h per week and probability of employment by 13 % points from a base of 43 %. We conclude that parents withdraw cash and in-kind transfers from their children to a value of between 22 and 86 % of what the child receives in EMA. This means we reject the hypothesis of an effectively altruistic head-of-household, and argue that making this cash transfer directly to the child produces higher child welfare than if the equivalent transfer were made to parents