Metabolic demands of a simulated smoke-diving drill

The main goal of this study was to update the Finnish smoke-diving drill (FSDD) and to measure the physical strain of and recovery from the drill. Furthermore, the aim was to compare the physical strain of contract and professional firefighters and effect of floor materials. The associations between aerobic capacity and physical strain were also studied. The updates made included an added hose pull task and updating the equipment used. Heart rate (HR), oxygen consumption (V̇O2), and blood lactate concentration ([La-]) of 32 professional and 5 contract firefighters were measured before, during, and 10 and 30 min after the updated drill. The mean HR during the drill was 78% and V̇O2 59% of maximum. HR and [La-] had not recovered to baseline levels after 30-minute recovery period. Physical strain was higher among contract firefighters and [La-] accumulation on rough floor surfaces. Better aerobic capacity was associated with reduced physical strain.

Development of mesothelioma-specific oncolytic immunotherapy enabled by immunopeptidomics of murine and human mesothelioma tumors

Malignant pleural mesothelioma (MPM) is an aggressive tumor with a poor prognosis. As the available therapeutic options show a lack of efficacy, novel therapeutic strategies are urgently needed. Given its T-cell infiltration, we hypothesized that MPM is a suitable target for therapeutic cancer vaccination. To date, research on mesothelioma has focused on the identification of molecular signatures to better classify and characterize the disease, and little is known about therapeutic targets that engage cytotoxic (CD8+) T cells. In this study we investigate the immunopeptidomic antigen-presented landscape of MPM in both murine (AB12 cell line) and human cell lines (H28, MSTO-211H, H2452, and JL1), as well as in patients' primary tumors. Applying state-of-the-art immuno-affinity purification methodologies, we identify MHC I-restricted peptides presented on the surface of malignant cells. We characterize in vitro the immunogenicity profile of the eluted peptides using T cells from human healthy donors and cancer patients. Furthermore, we use the most promising peptides to formulate an oncolytic virus-based precision immunotherapy (PeptiCRAd) and test its efficacy in a mouse model of mesothelioma in female mice. Overall, we demonstrate that the use of immunopeptidomic analysis in combination with oncolytic immunotherapy represents a feasible and effective strategy to tackle untreatable tumors.

Simultaneous metabolomics analysis of atrial tissue, pericardial fluid and blood reveal novel metabolite signatures of the pathophysiology and biomarkers related to permanent atrial fibrillation

Introduction

Atrial fibrillation (AF) is the most common, complex, and clinically relevant arrhythmia [1]. It is a growing medical condition associated with significant morbidity and mortality, but its pathophysiology has remained widely unknown [2].

Aims

We aim to unravel the complex pathophysiological mechanisms of AF and identify clinically relevant AF-related metabolites. We aim to identify targets for therapeutical interventions and biomarkers for AF diagnostics. Our study material is unique as we can safely study human heart and pericardial fluid in addition to blood, that has been mainly examined in previous studies.

Material and methods

Patients recruited were undergoing cardiac surgery due to valve defects at the University Hospital. For our research, we collected preoperative blood samples and intraoperative right atrial appendage biopsy and pericardial fluid. For our metabolomics study on AF patients, we selected 16 patients with permanent AF and 17 age, gender and underlying disease matched control patients (Fig. 1). Liquid chromatography mass spectrometry (LC-MS) was used to identify molecules and metabolites related to AF. We integrated targeted assays for absolute quantification of specific metabolites with untargeted metabolomics to discover novel compounds and metabolites.

Results

Untargeted mass spectrometry (MS) metabolite analysis identified altogether 15751 molecular features and metabolites divided unequally between the sample types (Fig. 2). Altogether, we found 1041 (p<0.05) metabolites from the heart tissue, 774 from the pericardial fluid and 382 from the blood. There were 61 metabolites associated with permanent AF that were found in all three sample types. The approach and our research set-up also allowed us to distinguish metabolites that entered directly from heart tissue to blood and those that remained in heart tissue and pericardial fluid. According to the identified metabolites in the heart tissue, permanent AF was associated with a clear metabolite signature including signs of dysregulated energy -, histidine -, glutathione -, purine -, sugar -, and lipid metabolism and antioxidant defense. Altogether we identified altered, circulating AF-related biomarkers including novel carnitines and acylcarnitines, aminoacids, metabolites from immune response and lipid metabolism. Among the highest statistical significance with qualifiable difference (multivariate α-level 0.0007) we found two novel circulating molecules with known MS spectrum and molecular weight.

Conclusions

We identified totally new pathophysiological processes and novel potential metabolites related to permanent AF to be used as AF biomarkers. Permanent AF is associated with dysreculation of multiple biologically relevant metabolic pathways.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Academy of FinlandThe Finnish Foundation for Cardiovascular Research

Wrist band photoplethysmography in detection of individual pulses in atrial fibrillation and algorithm-based detection of atrial fibrillation

AIMS

Atrial fibrillation (AF) is the most common tachyarrhythmia and a significant cause of cardioembolic strokes. Atrial fibrillation is often intermittent and asymptomatic making detection a major clinical challenge. We evaluated a photoplethysmography (PPG) wrist band in individual pulse detection in patients with AF and tested the reliability of two commonly used algorithms for AF detection.

METHODS AND RESULTS

A 5-min PPG was recorded from patients with AF or sinus rhythm (SR) with a wrist band and analysed with two AF detection algorithms; AFEvidence and COSEn. Simultaneously registered electrocardiogram served as the golden standard for rhythm analysis and was interpreted by two cardiologists. The study population consisted of 213 (106 AF, 107 SR) patients. The wrist band PPG achieved individual pulse detection with a sensitivity of 91.7 ± 11.2% and a positive predictive value (PPV) of 97.5 ± 4.6% for AF, with a sensitivity of 99.4 ± 1.5% [7.7% (95% confidence interval, 95% CI 5.5% to 9.9%); P < 0.001] and PPV of 98.1 ± 4.1% [0.6% (95% CI -0.6% to 1.7%); P = 0.350] for SR. The pulse detection sensitivity was lower 86.7 ± 13.9% with recent-onset AF (AF duration <48 h, n = 43, 40.6%) as compared to late AF (≥48 h, n = 63, 59.4%) with 95.1 ± 7.2% [-8.3% (95% CI -12.9% to -3.7%); P = 0.001]. For the detection of AF from the wrist band PPG, the sensitivities were 96.2%/95.3% and specificity 98.1% with two algorithms.

CONCLUSION

The wrist band PPG enabled accurate algorithm-based detection of AF with two AF detection algorithms and high individual pulse detection. Algorithms allowed accurate detection of AF from the PPG. A PPG wrist band provides an easy solution for AF screening.

224Wireless ECG embedded in a necklace enables reliable detection of atrial fibrillation

Funding Acknowledgements

Goverment grant, Heart2save Ltd cooperation.

Background/Introduction:

Atrial fibrillation (AF) is the most common arrhythmia and a fast-growing public health problem worldwide. Main and the most severe complication of AF is an embolic stroke. Approximately 25% of all strokes are caused by AF. AF is often symptomless and intermittent, making its detection and diagnosing challenging. Many AF patients have both symptomatic and asymptomatic periods of arrhythmia. In addition, during the early stage of the disease, AF is often paroxysmal making the diagnosis of AF a major clinical challenge.

Purpose

Wearable ECG devices could enable repetitive rhythm monitoring over a long term and thus improve the probability of AF detection. Wearable devices have the advantage of being easily available. However, they also need to be reliable and their design should appeal customers. Our aim was to study the suitability and reliability of novel measurement technique (necklace-ECG, Figure1) for the diagnosis of AF.

Methods

The study population consisted of 145 adult volunteers at Kuopio University Hospital emergency department (66 AF and 79 sinus rhythm (SR), diagnosed from continuous 3-lead ECG recording. All study subjects performed a thirty-second self-performed ECG recording with a single-lead necklace-embedded ECG recorder (necklace-ECG) keeping the recorder between palms of their hands. The ECG recordings were analyzed with automatic AF detection algorithm. Two cardiologists interpreted independently in blinded fashion the necklace-ECG recordings and simultaneously registered 3-lead ECGs which served as golden standard for the final rhythm diagnosis.

Results

Necklace-ECG produced an interpretable ECG recording in 91.0%/86.2% patients (Doc1/Doc2, respectively). Additionally, 93.1% of ECG recordings were interpretable by the automatic analysis service (98.7% in SR patients and 86.4% of AF patients).

Base on the necklace ECG recording, cardiologists were able to diagnose AF with sensitivity of 98.2%/96.3% (Doc1/Doc2, respectively) and specificity of 100% (Doc1 and Doc2, respectively). The automatic arrhythmia algorithm diagnosed AF with sensitivity of 94.7% and specificity of 100%.

Conclusions

The necklace-ECG device produces ECG recording with sufficient quality for the detection of AF with good sensitivity and specificity as evaluated both by cardiologist and automated AF-detection algorithm. Thus, wearable necklace-ECG provides a new and easy method for screening, identifying and diagnosing AF.

Abstract Figure 1

The classification of osteonecrosis in patients with cancer: validation of a new radiological classification system

AIM

To validate a new, non-joint-specific radiological classification system that is suitable regardless of the site of the osteonecrosis (ON) in patients with cancer.

MATERIAL AND METHODS

Critical deficiencies in the existing ON classification systems were identified and a new, non-joint-specific radiological classification system was developed. Seventy-two magnetic resonance imaging (MRI) images of patients with cancer and ON lesions were graded, and the validation of the new system was performed by assessing inter- and intra-observer reliability.

RESULTS

Intra-observer reliability of ON grading was good or very good, with kappa values of 0.79-0.86. Interobserver agreement was lower but still good, with kappa values of 0.62-0.77. Ninety-eight percent of all intra- or interobserver differences were within one grade. Interobserver reliability of assessing the location of ON was very good, with kappa values of 0.93-0.98.

CONCLUSION

All the available radiological ON classification systems are joint specific. This limitation has spurred the development of multiple systems, which has led to the insufficient use of classifications in ON studies among patients with cancer. The introduced radiological classification system overcomes the problem of joint-specificity, was found to be reliable, and can be used to classify all ON lesions regardless of the affected site.

Preventive strategies for atrial fibrillation after cardiac surgery in Nordic countries

BACKGROUND AND AIMS

Atrial fibrillation is a common arrhythmia after cardiac surgery. It increases morbidity, length of hospital stay, and costs of operative treatment. Beta-blockers, sotalol, amiodarone, corticosteroids, and biatrial pacing have been shown to be efficient in the prevention of postoperative atrial fibrillation. The aim of this study was to find out how widely different prophylactic strategies for postoperative atrial fibrillation are used in Scandinavian countries.

MATERIAL AND METHODS

An online link for a questionnaire was emailed to (214) cardiac surgeons in Finland, Sweden, Norway, Denmark, and Estonia to assess the use of prophylactic methods for postoperative atrial fibrillation.

RESULTS

A total of 97 surgeons responded to the survey. Oral beta-blockers were routinely used for atrial fibrillation prophylaxis by 62% of responders. The main reasons for nonuse of beta-blockers were that responders were unconvinced of the evidence of benefit or they preferred some alternative prophylaxis. Intravenous beta-blockers were used frequently by 6% of responders. Amiodarone was used for prophylaxis by 18% of responders. Nonusers were unconvinced of its efficacy, were afraid of its complications, or found its use too cumbersome. Other prophylactic atrial fibrillation strategies that were used are as follows: sotalol by 2%, magnesium by 17%, corticosteroids by 1%, and atrial pacing by 11% of respondents.

CONCLUSIONS

There is still widely varying implementation of strategies for atrial fibrillation prophylaxis among Scandinavian cardiac surgeons. Lack of confidence in the efficacy of these approaches is the main rationale for nonimplementation.

Intravenous Metoprolol versus Biatrial Pacing in the Prevention of Atrial Fibrillation after Coronary Artery Bypass Surgery: A Prospective Randomized Open Trial

Background and Aims:

Atrial fibrillation (AF) is the most common arrhythmia after coronary arteryby pass surgery (CABG). Intravenous metoprolol and biatrial pacing have been reported to be effective in AF prophylaxis after cardiac surgery. The purpose of this trial was to compare the efficacy of intravenous metoprolol versus biatrial pacing combined with oral metoprolol in the prevention of AF after CABG.

Methods:

A single-centre prospective randomized open trial of 165 consecutive patients undergoing their first CABG. Patients were randomized to receive either intravenous metoprolol infusion 1–3 mg per hour or biatrial overdrive pacing and oral metoprolol (50–150mg) daily for 72 hours after CABG starting immediately after the surgery. AAI pacing with a pacing rate of 10 beats/minute above the baseline heart rate was used. Patients had continuous ECG-monitoring. The primaryend point was the first episode of AF.

Results:

The incidence of postoperative AF in the intravenous metoprolol and biatrial pacing groups did not differ from each other (14% vs. 18% respecively, p = 0.66). There was no difference in the time of AF on set between the groups (28.2 ± 16.2 h vs. 30.1 ± 21.2 h respectively, p = 0.8). Intravenous metoprolol infusion had to be temporarily interrupted for one hour in eleven patients because of hypotension or bradycardia. One case of bleeding from the left atria related to the pacemaker electrode wire was found.

Conclusion:

We found no difference in the incidence of AF between patients treated with intravenous metoprolol or the combination of biatrial pacing and oral metoprolol.

Reliability of the evaluation of multidetector computed tomography images from the scanner's console in high-energy blunt-trauma patients

PURPOSE

To evaluate the reliability of a structured 5-min evaluation of multidetector computed tomography (MDCT) images from the scanner's console in high-energy trauma patients.

MATERIAL AND METHODS

Forty patients were scanned with four-slice MDCT using a standardized trauma protocol. Image evaluation covered the thorax, abdomen, and pelvis. The radiologist scrolled axial images on the scanner's console using three different window settings (lung, soft tissue, and bone) and performed a prospective structured evaluation of the traumatic lesions. The findings were compared to the final radiological diagnosis of the MDCT data made on a PACS workstation, the operative findings, and the clinical follow-up.

RESULTS

Evaluation from the scanner's console enabled the diagnosis of all potential life-threatening injuries, the sensitivity for all injuries being 60% and specificity 98%.

CONCLUSION

A PACS workstation is needed for the final diagnosis of all injuries, but this rapid screening method can reliably detect all injuries that require instant care.

Adenosine 5'-monophosphate is a selective inhibitor of the brown adipocyte nonselective cation channel

Calcium-activated nonselective cation channels (NSC(Ca)) in brown adipocytes are inhibited by several nucleotides acting on the cytosolic side of the membrane. We used excised inside-out patches from rat brown adipocytes to identify important nucleotide structures for NSC-channel inhibition. We found that 100 microM 5'-AMP inhibited NSC-channel activity more than did ATP or ADP. Adenosine was a weak inhibitor, whereas adenine and ribose-5-phosphate had no effect. The channel activity was effectively blocked by 10 microM AMP, but it was unaffected by 10 microM cAMP, CMP, GMP, IMP, TMP or UMP. Dose-response studies yielded IC(50)-values of 4 microM for AMP and 32 microM for cAMP. dAMP was as effective as AMP, but all 5'-phosphate group modifications on AMP dramatically lowered the inhibitory effect. 10 microM of the AMP precursor adenylosuccinate weakly inhibited the channel activity. An increase in AMP concentration from 1 to 10 microM shifted the EC(50) for Ca(2+) activation almost 1 order of magnitude; a Schild plot analysis yielded a K(B) value of 0.3 microM for AMP. We conclude that AMP is the most efficacious endogenous nucleotide inhibitor of the brown adipocyte nonselective cation channel (NSC(Ca/AMP)) yet identified and that there is functional competition between Ca(2+) and AMP. The brown adipocyte NSC(Ca/AMP) thus appears to be functionally different from the NSC(Ca,PKA) in the exocrine pancreas and the NSC-(Ca,cAMP) in the endocrine pancreas, but similar to the NSC(Ca/AMP) in the endocrine pancreas.

Novel galanin receptor ligands

Galanin is a neuroendocrine peptide which is 29/30 amino acids in length and is recognised by G-protein-coupled central nervous system receptors via its N-terminus. We synthesised several galanin receptor ligands and fragments around C-terminal extensions of galanin(1-13) to yield chimeric peptides with C-terminals corresponding to bioactive peptides like bradykinin(2-9), mastoparan, neuropeptide Y(25-36) or substance P(5-11), respectively. We also synthesised short galanin analogs in which galanin(1-13) was C-terminally elongated with Lys14; different pharmacologically active small molecules were then attached to the epsilon-amino group of Lys14. Several cysteine-substituted linear and ring closed analogs of galanin(1-9) and galanin(1-16) were also synthesised. The equilibrium binding constants for these peptides at hypothalamic galanin receptors were determined and found in the subnanomolar to micromolar range. The large number of peptides and their binding affinities presented here permit structure-activity relationship analysis of peptide-type ligands to galanin receptors.