In vitro differentiation of W8B2+ human cardiac stem cells: gene expression of ionic channels and spontaneous calcium activity.

BACKGROUND: Human cardiac stem cells expressing the W8B2 marker (W8B2+ CSCs) were recently identified and proposed as a new model of multipotent CSCs capable of differentiating into smooth muscle cells, endothelial cells and immature myocytes. Nevertheless, no characterization of ion channel or calcium activity during the differentiation of these stem cells has been reported. METHODS: The objectives of this study were thus to analyze (using the TaqMan Low-Density Array technique) the gene profile of W8B2+ CSCs pertaining to the regulation of ion channels, transporters and other players involved in the calcium homeostasis of these cells. We also analyzed spontaneous calcium activity (via the GCaMP calcium probe) during the in vitro differentiation of W8B2+ CSCs into cardiac myocytes. RESULTS: Our results show an entirely different electrophysiological genomic profile between W8B2+ CSCs before and after differentiation. Some specific nodal genes, such as Tbx3, HCN, ICaT, L, KV, and NCX, are overexpressed after this differentiation. In addition, we reveal spontaneous calcium activity or a calcium clock whose kinetics change during the differentiation process. A pharmacological study carried out on differentiated W8B2+ CSCs showed that the NCX exchanger and IP3 stores play a fundamental role in the generation of these calcium oscillations. CONCLUSIONS: Taken together, the present results provide important information on ion channel expression and intrinsic calcium dynamics during the differentiation process of stem cells expressing the W8B2 marker.

Defining the optimal duration for normothermic regional perfusion in the kidney donor: A porcine preclinical study.

Kidneys from donation after circulatory death (DCD) are highly sensitive to ischemia-reperfusion injury and thus require careful reconditioning, such as normothermic regional perfusion (NRP). However, the optimal NRP protocol remains to be characterized. NRP was modeled in a DCD porcine model (30 minutes of cardiac arrest) for 2, 4, or 6 hours compared to a control group (No-NRP); kidneys were machine-preserved and allotransplanted. NRP appeared to permit recovery from warm ischemia, possibly due to an increased expression of HIF1α-dependent survival pathway. At 2 hours, blood levels of ischemic injury biomarkers increased: creatinine, lactate/pyruvate ratio, LDH, AST, NGAL, KIM-1, CD40 ligand, and soluble-tissue-factor. All these markers then decreased with time; however, AST, NGAL, and KIM-1 increased again at 6 hours. Hemoglobin and platelets decreased at 6 hours, after which the procedure became difficult to maintain. Regarding inflammation, active tissue-factor, cleaved PAR-2 and MCP-1 increased by 4-6 hours, but not TNF-α and iNOS. Compared to No-NRP, NRP kidneys showed lower resistance during hypothermic machine perfusion (HMP), likely associated with pe-NRP eNOS activation. Kidneys transplanted after 4 and 6 hours of NRP showed better function and outcome, compared to No-NRP. In conclusion, our results confirm the mechanistic benefits of NRP and highlight 4 hours as its optimal duration, after which injury markers appear.

Modulation of cellular membrane properties as a potential therapeutic strategy to counter lipointoxication in obstructive pulmonary diseases.

Maintaining the equilibrium between saturated and unsaturated fatty acids within membrane phospholipids (PLs) is crucial to sustain the optimal membrane biophysical properties, compatible with selective organelle-based processes. Lipointoxication is a pathological condition under which saturated PLs tend to accumulate within the cell at the expense of unsaturated species, with major impacts on organelle function. Here, we show that human bronchial epithelial cells extracted from lungs of patients with Obstructive Pulmonary Diseases (OPDs), i. e. Cystic Fibrosis (CF) individuals and Smokers, display a characteristic lipointoxication signature, with excessive amounts of saturated PLs. Reconstitution of this signature in cellulo and in silico revealed that such an imbalance results in altered membrane properties and in a dramatic disorganization of the intracellular network of bronchial epithelial cells, in a process which can account for several OPD traits. Such features include Endoplasmic Reticulum-stress, constitutive IL8 secretion, bronchoconstriction and, ultimately, epithelial cell death by apoptosis. We also demonstrate that a recently-identified lipid-like molecule, which has been shown to behave as a "membrane-reshaper", counters all the lipointoxication hallmarks tested. Altogether, these insights highlight the modulation of membrane properties as a potential new strategy to heal and prevent highly detrimental symptoms associated with OPDs.

Subcutaneous cardioverter defibrillator has longer time to therapy but is less cardiotoxic than transvenous cardioverter defibrillator. Study carried out in a preclinical porcine model.

Aims: Totally subcutaneous implantable cardioverter defibrillator (S-ICD) delivers higher shock energy and can have longer time to therapy compared to transvenous implantable cardioverter defibrillator (T-ICD). Aim of the study was to compare time to therapy and to investigate cardiac, cerebral and systemic injuries of S-ICD and T-ICD shocks delivered after ventricular fibrillation (VF) induction. Methods and results: Fourteen pigs were randomly implanted with a S-ICD (n = 7) or a T-ICD (n = 7). Five VF episodes were induced in each pig. For each VF episode, up to two shocks could be delivered by the T-ICD or the S-ICD to terminate the arrhythmia. Cardiac, systemic, and cerebral toxicity were monitored. Mean time to therapy was longer in the S-ICD group compared to the T-ICD group (19[18; 23] s vs. 9 [7; 10] s; P = 0.001, respectively). High-sensitivity troponin T levels were significantly higher in the T-ICD group from 1 to 24 h after the procedure (P ≤ 0.02). Creatine phosphokinase activity levels were significantly higher in the S-ICD group, at 3, 6, and 24 h after the procedure (P ≤ 0.05). Lactate levels were not significantly different between groups. S100 protein level was similar in both groups at 1 h after the procedure and then decreased in the T-ICD group compared to the S-ICD group (P = 0.04). Conclusions: Time to therapy in S-ICD was twice as long as for T-ICD, but didn't induce relevant brain injury. Conversely, S-ICD shocks were less cardiotoxic than T-ICD shocks.

Medical and Economic Evaluation of FOREseal Bioabsorbable Reinforcement Sleeves Compared With Current Standard of Care for Reducing Air Leakage Duration After Lung Resection for Malignancy: A Randomized Trial.

OBJECTIVE: The objective of this study was to determine the efficacy of alginate staple-line reinforcement of fissure openings as compared with stapling alone, with or without tissue sealant or glue, in reducing the incidence and duration of air leakage after pulmonary lobectomy for malignancy. SUMMARY BACKGROUND DATA: No randomized trial evaluating alginate staple-line reinforcement has been performed to date. METHODS: The Staple-line Reinforcement for Prevention of Pulmonary Air Leakage study was a multicenter randomized trial, with blinded evaluation of endpoints. Patients over 18 years of age scheduled for elective open lobectomy or bilobectomy for malignancy were eligible for enrollment. At thoracotomy, patients were deemed ineligible if an unanticipated pneumonectomy was indicated, or if air leakage occurred after the liberation of pleural adhesions. Otherwise, if the fissure was incomplete or the lung had an emphysematous appearance, patients were randomized to either standard management or interventional procedure consisting of fissure opening with linear cutting staplers buttressed with paired alginate sleeves (FOREseal). The number of eligible patients necessary in each randomization arm was estimated to be 190, and an outcomes analysis was performed on an intention-to-treat basis. RESULTS: Of the 611 patients consented to study enrollment, 380 met the inclusion criteria and were randomized. Based on an intention-to-treat analysis, the primary endpoint of air leak duration was not different between the 2 groups: 1 day (range: 0-2 d) in the FOREseal group and 1 day (range: 0-3 d) in the control group (P = 0.8357). In addition, the 2 groups were similar in terms of the proportion of patients presenting with prolonged air leakage (7.8% in the FOREseal group vs 11.3% in the control group, P = 0.264) and the average duration of chest drainage (P = 0.107). Procedure costs were comparable for both groups. CONCLUSIONS: FOREseal did not demonstrate a significant advantage over standard treatment alone.

ANO1 contributes to angiotensin-II-activated Ca2+-dependent Cl- current in human atrial fibroblasts.

Cardiac fibroblasts are an integral part of the myocardial tissue and contribute to its remodelling. This study characterises for the first time the calcium-dependent chloride channels (CaCC) in the plasma membrane of primary human atrial cardiac fibroblasts by means of the iodide efflux and the patch clamp methods. The calcium ionophore A23187 and Angiotensin II (Ang II) activate a chloride conductance in cardiac fibroblasts that shares pharmacological similarities with calcium-dependent chloride channels. This chloride conductance is depressed by RNAi-mediated selective Anoctamine 1 (ANO1) but not by Anoctamine 2 (ANO2) which has been revealed as CaCC and is inhibited by the selective ANO1 inhibitor, T16inh-A01. The effect of Ang II on anion efflux is mediated through AT1 receptors (with an EC50 = 13.8 ± 1.3 nM). The decrease of anion efflux by calphostin C and bisindolylmaleimide I (BIM I) suggests that chloride conductance activation is dependent on PKC. We conclude that ANO1 contributes to CaCC current in human cardiac fibroblasts and that this is regulated by Ang II acting via the AT1 receptor pathway.

Bronchorelaxation of the human bronchi by CFTR activators.

The airway functions are profoundly affected in many diseases including asthma, COPD and cystic fibrosis (CF). CF the most common lethal autosomal recessive genetic disease is caused by mutations of the CFTR (Cystic Fibrosis transmembrane Conductance Regulator) gene, which normally encodes a multifunctional and integral membrane cAMP regulated and ATP gated Cl(-) channel expressed in airway epithelial cells. Using human lung tissues obtained from patients undergoing surgery for lung cancer, we demonstrated that CFTR participates in bronchorelaxation. Using human bronchial smooth muscle cells (HBSMC), we applied iodide influx assay to analyze the CFTR-dependent ionic transport and immunofluorescence technique to localize CFTR proteins. Moreover, the relaxation was studied in isolated human bronchial segments after pre-contraction with carbachol to determine the implication of CFTR in bronchodilation. We found in HBSMC that the pharmacology and regulation of CFTR is similar to that of its epithelial counterpart both for activation (using forskolin/genistein or a benzo[c]quinolizinium derivative) and for inhibition (CFTR(inh)-172 and GPinh5a). With human bronchial rings, we observed that whatever the compound used including salbutamol, the activation of muscular CFTR leads to a bronchodilation after constriction with carbachol. Altogether, these observations revealed that CFTR in the human airways is expressed in bronchial smooth muscle cells and can be pharmacologically manipulated leading to the hypothesis that this ionic channel could contribute to bronchodilation in human.

Impact of surgical approach on 90-day mortality after lung resection for nonsmall cell lung cancer in high-risk operable patients.

Introduction: Non-small cell lung cancer (NSCLC) is often associated with compromised lung function. Real-world data on the impact of surgical approach in NSCLC patients with compromised lung function are still lacking. The objective of this study is to assess the potential impact of minimally invasive surgery (MIS) on 90-day post-operative mortality after anatomic lung resection in high-risk operable NSCLC patients. Methods: We conducted a retrospective multicentre study including all patients who underwent anatomic lung resection between January 2010 and October 2021 and registered in the Epithor database. High-risk patients were defined as those with a forced expiratory volume in 1 s (FEV1) or diffusing capacity of the lung for carbon monoxide (DLCO) value below 50%. Co-primary end-points were the impact of risk status on 90-day mortality and the impact of MIS on 90-day mortality in high-risk patients. Results: Of the 46 909 patients who met the inclusion criteria, 42 214 patients (90%) with both preoperative FEV1 and DLCO above 50% were included in the low-risk group, and 4695 patients (10%) with preoperative FEV1 and/or preoperative DLCO below 50% were included in the high-risk group. The 90-day mortality rate was significantly higher in the high-risk group compared to the low-risk group (280 (5.96%) versus 1301 (3.18%); p<0.0001). In high-risk patients, MIS was associated with lower 90-day mortality compared to open surgery in univariate analysis (OR=0.04 (0.02-0.05), p<0.001) and in multivariable analysis after propensity score matching (OR=0.46 (0.30-0.69), p<0.001). High-risk patients operated through MIS had a similar 90-day mortality rate compared to low-risk patients in general (3.10% versus 3.18% respectively). Conclusion: By examining the impact of surgical approaches on 90-day mortality using a nationwide database, we found that either preoperative FEV1 or DLCO below 50% is associated with higher 90-day mortality, which can be reduced by using minimally invasive surgical approaches. High-risk patients operated through MIS have a similar 90-day mortality rate as low-risk patients.

Late postcardiotomy sternal dehiscence: a simple approach using Stratos® system.

Management of late sternal dehiscence is challenging and time consuming. Although numerous techniques exist including rewiring and titanium plates screwing to stabilize the sternum, we describe an alternative technique by using four titanium clips and one connecting bar.

Transient receptor potential canonical channel 6 links Ca2+ mishandling to cystic fibrosis transmembrane conductance regulator channel dysfunction in cystic fibrosis.

In cystic fibrosis (CF), abnormal control of cellular Ca(2+) homeostasis is observed. We hypothesized that transient receptor potential canonical (TRPC) channels could be a link between the abnormal Ca(2+) concentrations in CF cells and cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. We measured the TRPC and CFTR activities (using patch clamp and fluorescent probes) and interactions (using Western blotting and co-immunoprecipitation) in CF and non-CF human epithelial cells treated with specific and scrambled small interfering RNA (siRNA). The TRPC6-mediated Ca(2+) influx was abnormally increased in CF compared with non-CF cells. After correction of abnormal F508 deletion (del)-CFTR trafficking in CF cells, the level of TRPC6-dependent Ca(2+) influx was also normalized. In CF cells, siRNA-TRPC6 reduced this abnormal Ca(2+) influx. In non-CF cells, siRNA-TRPC6 reduced the Ca(2+) influx and activity wild-type (wt)-CFTR. Co-immunoprecipitation experiments revealed TRPC6/CFTR and TRPC6/F508 del-CFTR interactions in CF or non-CF epithelial cells. Although siRNA-CFTR reduced the activity of wt-CFTR in non-CF cells and of F508 del-CFTR in corrected CF cells, it also enhanced TRPC6-dependent Ca(2+) influx in non-CF cells, mimicking the results obtained in CF cells. Finally, this functional and reciprocal coupling between CFTR and TRPC6 was also detected in non-CF ciliated human epithelial cells freshly isolated from lung samples. These data indicate that TRPC6 and CFTR are functionally and reciprocally coupled within a molecular complex in airway epithelial human cells. Because this functional coupling is lost in CF cells, the TRPC6-dependent Ca(2+) influx is abnormal.

Aortic valve repair of non-penetrating traumatic aortic regurgitation.

Traumatic aortic valve rupture is an extremely rare complication of non-penetrating cardiac injury, and may be caused by a tear or avulsion of the cusp or commissure. Transesophageal echocardiography represents the most important tool for evaluating the nature and extent of such traumatic lesions. The case is reported of a 74-year-old male who had sustained a non-penetrating chest injury in a motor vehicle accident, and suffered from aortic regurgitation as a result of rupture of the normal aortic valve. A primary valve repair was performed using an autologous pericardium patch.

Dissecting Thoracic Aneurysm in Takayasu Arteritis With Concomitant Tuberculosis.

We present a case of dissecting aneurysm of ascending aorta in a 15-year-old patient secondary to Takayasu arteritis with concomitant tuberculosis, with an emphasis on multimodality imaging findings and to illustrate preoperative and postoperative medical management. Antituberculosis therapy, high-dose corticosteroids, antiplatelet therapy, and ß-blockers were administrated during the initial active phase. The patient presented with acute chest pain 3 months after medical therapy initiation. We performed an ascending aorta and aortic arch replacement with branched Dacron grafts. Only a handful of similar, but not identical, cases of Takayasu arteritis with concomitant tuberculosis leading to aortic dissection have been described previously.

A high-resolution ICP-MS method for the determination of 38 inorganic elements in human whole blood, urine, hair and tissues after microwave digestion.

Inductively coupled plasma-mass spectrometry (ICP-MS) is currently the reference method for the determination of inorganic elements, and has many applications in healthcare and the environmental field. The objective of the present study was to develop and validate a high-resolution ICP-MS method for the simultaneous quantification of 38 elements in samples of human whole blood, urine, hair and tissues after microwave mineralization. The samples were incubated with nitric acid, hydrogen peroxide and internal standards prior to microwave mineralization for 25 min. The analysis was performed with an Element XR ICP-MS and validated using commercial reference standards (whole blood, urine, and hair) and in-house quality control samples. The 38 elements were detected in low-, medium- or high-resolution mode, depending on interferences and sensitivity. The lower and upper limits of quantification were adjusted for each element. The method was linear for all elements (correlation coefficient >0.996), and the inter- and intraday precision values (coefficient of variation) were below 15%. Samples from a clinical trial were used to confirm the high-resolution ICP-MS method's suitability for the assessment of patient samples.

The heart rate-lowering agent ivabradine inhibits the pacemaker current I(f) in human atrial myocytes.

INTRODUCTION: It has been speculated that pacemaker current (I(f)) in human atria could play a role in causing ectopic atrial automaticity. Ivabradine is a novel selective and specific I(f) inhibitor in the sinus node that reduces heart rate without any negative inotropic effect. The aim of the study was to explore possible effects of ivabradine on I(f) in atrial myocytes. METHODS AND RESULTS: Using patch-clamp technique, we studied effects of ivabradine on I(f) present in atrial myocytes isolated from human right appendages of patients undergoing cardiac surgery. The identification of HCN isoforms was obtained by means of multiplex single-cell RT-PCR. Ivabradine induced a marked concentration and use-dependent I(f) inhibition with an IC50 at steady state of 2.9 microM. Time constant of block development (Tau(on)) decreases with the increase in the ivabradine concentration. Use-dependent inhibition induced by ivabradine (3 microM) was not modified in the presence of cAMP (10 microM) in the pipette solution. Multiplex single-cell RT-PCR indicates that the major HCN gene subtype detected in atria was HCN2. HCN4 is detected weakly and HCN1 is not significantly detected. CONCLUSIONS: Ivabradine inhibits I(f) current in the nonpacemaker cell with characteristics similar to those described previously in rabbit sinus node cells, but revealed a lesser sensitivity for I(f) recorded in human atrial cell than hHCN4 subunits considered as the major contributors to native f-channels in human sinoatrial node. A potential protection of atrial arrhythmias by ivabradine is discussed.

Medicoeconomic analysis of lobectomy using thoracoscopy versus thoracotomy for lung cancer: a study protocol for a multicentre randomised controlled trial (Lungsco01).

INTRODUCTION: In the last decade, video-assisted thoracoscopic surgery (VATS) lobectomy for non-small cell lung cancer (NSCLC) has had a major effect on thoracic surgery. Retrospective series have reported benefits of VATS when compared with open thoracotomy in terms of postoperative pain, postoperative complications and length of hospital stay. However, no large randomised control trial has been conducted to assess the reality of the potential benefits of VATS lobectomy or its medicoeconomic impact. METHODS AND ANALYSIS: The French National Institute of Health funded Lungsco01 to determine whether VATS for lobectomy is superior to open thoracotomy for the treatment of NSCLC in terms of economic cost to society. This trial will also include an analysis of postoperative outcomes, the length of hospital stay, the quality of life, long-term survival and locoregional recurrence. The study design is a two-arm parallel randomised controlled trial comparing VATS lobectomy with lobectomy using thoracotomy for the treatment of NSCLC. Patients will be eligible if they have proven or suspected lung cancer which could be treated by lobectomy. Patients will be randomised via an independent service. All patients will be monitored according to standard thoracic surgical practices. All patients will be evaluated at day 1, day 30, month 3, month 6, month 12 and then every year for 2 years thereafter. The recruitment target is 600 patients. ETHICS AND DISSEMINATION: The protocol has been approved by the French National Research Ethics Committee (CPP Est I: 09/06/2015) and the French Medicines Agency (09/06/2015). Results will be presented at national and international meetings and conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT02502318.