Combination of chest compressions and interposed abdominal compressions in a swine model of ventricular fibrillation.

PURPOSE: The aim of this study was to investigate the effects of the combination of chest compressions and interposed abdominal compressions (IAC-CPR) in a swine model of ventricular fibrillation (VF). METHODS: Twenty healthy female Landrace-Large White pigs were the study subjects. At the end of the eighth minute of VF, animals in the control group (Group A) received chest compressions at a rate of 100/min, while animals in the experimental group received chest compressions and simultaneous interposed abdominal compressions (CC-IAC - Group B), both at a rate of 100/min. The primary end point of the experiment was return of spontaneous circulation (ROSC). Secondary outcomes were 48-h survival rate and 48-h neurologic outcome. RESULTS: Six animals (60%) from Group A and 9 animals (90%) from Group B achieved ROSC (P=.121). There was a statistically significant difference in systolic aortic pressure, mean aortic pressure, right atrial pressures, and end-tidal carbon dioxide (ETCO2) between the two groups during the first cycle of CPR, while during the second cycle, diastolic aortic pressure was significantly higher in Group B. Coronary perfusion pressure (CPP) values in group B were significantly higher compared with those in Group A during the first and second cycle of CPR. Neurologic examination was statistically significantly better in Group B (75.00±10.00 vs. 90.00±10.00, P=.037). CONCLUSION: ROSC did not differ statistically significant in the IAC-CPR compared to the CPR group only, while CPP was significantly higher in IAC-CPR-treated animals.

Polarity proteins and Rho GTPases cooperate to spatially organise epithelial actin-based protrusions.

Different actin-filament-based structures co-exist in many cells. Here, we characterise dynamic actin-based protrusions that form at distinct positions within columnar epithelial cells, focusing on basal filopodia and sheet-like intermediate-level protrusions that extend between surrounding epithelial cells. Using a genetic analysis, we found that the form and distribution of these actin-filament-based structures depends on the activities of apical polarity determinants, not on basal integrin signalling. Bazooka/Par3 acts upstream of the RacGEF Sif/TIAM1 to limit filopodia to the basal domain, whereas Cdc42, aPKC and Par6 are required for normal protrusion morphology and dynamics. Downstream of these polarity regulators, Sif/TIAM1, Rac, SCAR and Arp2/3 complexes catalyse actin nucleation to generate lamellipodia and filopodia, whose form depends on the level of Rac activation. Taken together, these data reveal a role for Baz/Par3 in the establishment of an intercellular gradient of Rac inhibition, from apical to basal, and an intimate association between different apically concentrated Par proteins and Rho-family GTPases in the regulation of the distribution and structure of the polarised epithelial actin cytoskeleton.

SCAR/WAVE is activated at mitosis and drives myosin-independent cytokinesis.

Cell division requires the tight coordination of multiple cytoskeletal pathways. The best understood of these involves myosin-II-dependent constriction around the cell equator, but both Dictyostelium and mammalian cells also use a parallel, adhesion-dependent mechanism to generate furrows. We show that the actin nucleation factor SCAR/WAVE is strongly activated during Dictyostelium cytokinesis. This activation localises to large polar protrusions, driving separation of the daughter cells. This continues for 10 minutes after division before the daughter cells revert to normal random motility, indicating that this is a tightly regulated process. We demonstrate that SCAR activity is essential to drive myosin-II-independent cytokinesis, and stabilises the furrow, ensuring symmetrical division. SCAR is also responsible for the generation of MiDASes, mitosis-specific actin-rich adhesions. Loss of SCAR in both Dictyostelium and Drosophila leads to a similar mitotic phenotype, with severe mitotic blebbing, indicating conserved functionality. We also find that the microtubule end-binding protein EB1 is required to restrict SCAR localisation and direct migration. EB1-null cells also exhibit decreased adhesion during mitosis. Our data reveal a spindle-directed signalling pathway that regulates SCAR activity, migration and adhesion at mitosis.

Screening Mutants by Single Fly Genomic PCR.

Imprecise P-element excision or FRT-mediated recombination is routinely performed to mutagenize a gene of interest. It is, however, tedious to maintain all independent and individual excised mutant fly lines before the presence of a mutation is confirmed. Here, we provide a method to detect and confirm the presence of a mutation, as and when mutant flies are generated. By allowing for the maintenance and expansion of only the confirmed mutant lines, this protocol will help to save time, money, and space.

Cdc42, Par6, and aPKC regulate Arp2/3-mediated endocytosis to control local adherens junction stability.

BACKGROUND: By acting as a dynamic link between adjacent cells in a monolayer, adherens junctions (AJs) maintain the integrity of epithelial tissues while allowing for neighbor exchange. Although it is not currently understood how this combination of AJ stability and plasticity is achieved, junctionally associated actin filaments are likely to play a role, because actin-based structures have been implicated in AJ organization and in the regulation of junctional turnover. RESULTS: Here, through exploring the role of actin cytoskeletal regulators in the developing Drosophila notum, we have identified a critical role for Cdc42-aPKC-Par6 in the maintenance of AJ organization. In this system, the loss or inhibition of Cdc42-aPKC-Par6 leads to junctional discontinuities, the formation of ectopic junctional structures, and defects in apical actin cytoskeletal organization. Affected cells also undergo progressive apical constriction and, frequently, delamination. Surprisingly, this Cdc42-aPKC-Par6-dependent regulation of junctional stability was found to be independent of several well-known targets of Cdc42-aPKC-Par6: Baz, Lgl, Rac, and SCAR. However, similar AJ defects are observed in wasp, arp2/3, and dynamin mutant cells, suggesting a requirement for actin-mediated endocytosis in the maintenance of junctional stability downstream of Cdc42. This was confirmed in endocytosis assays, which revealed a requirement for Cdc42, Arp2/3, and Dynamin for normal rates of E-cadherin internalization. CONCLUSIONS: By focusing on the molecular mechanisms required to maintain an epithelium, this analysis reveals a novel role for the epithelial polarity machinery, Cdc42-Par6-aPKC, in local AJ remodeling through the control of Arp2/3-dependent endocytosis.

Generation and live imaging of tumors with specific genotypes in the living fly pupa.

This protocol describes the step-by-step generation of tumors with specific genotypes on the dorsal thorax epithelium of the fly. This in vivo system allows the imaging of tumor cell morphology and behavior in high spatial and temporal resolution. Phenotypes such as cell invasion, cell division, and tumor size can be quantified and compared to specific controls or to the neighboring wild-type tissue. Thus, this model allows the study of conserved genes that enhance or suppress epithelial tumor progression. For complete details on the use and execution of this protocol, please refer to Canales Coutiño et al. (2020).

In vivo Evaluation of a Newly Synthesized Acetylcholinesterase Inhibitor in a Transgenic Drosophila Model of Alzheimer's Disease.

Alzheimer's disease is a neurodegenerative disease characterized by disrupted memory, learning functions, reduced life expectancy, and locomotor dysfunction, as a result of the accumulation and aggregation of amyloid peptides that cause neuronal damage in neuronal circuits. In the current study, we exploited a transgenic Drosophila melanogaster line, expressing amyloid-ß peptides to investigate the efficacy of a newly synthesized acetylcholinesterase inhibitor, named XJP-1, as a potential AD therapy. Behavioral assays and confocal microscopy were used to characterize the drug effect on AD symptomatology and amyloid peptide deposition. The symptomatology induced in this particular transgenic model recapitulates the scenario observed in human AD patients, showing a shortened lifespan and reduced locomotor functions, along with a significant accumulation of amyloid plaques in the brain. XJP-1 treatment resulted in a significant improvement of AD symptoms and a reduction of amyloid plaques by diminishing the amyloid aggregation rate. In comparison with clinically effective AD drugs, our results demonstrated that XJP-1 has similar effects on AD symptomatology, but at 10 times lower drug concentration than donepezil. It also showed an earlier beneficial effect on the reduction of amyloid plaques at 10 days after drug treatment, as observed for donepezil at 20 days, while the other drugs tested have no such effect. As a novel and potent AChE inhibitor, our study demonstrates that inhibition of the enzyme AChE by XJP-1 treatment improves the amyloid-induced symptomatology in Drosophila, by reducing the number of amyloid plaques within the fruit fly CNS. Thus, compound XJP-1 has the therapeutic potential to be further investigated for the treatment of AD.

CG7379 and ING1 suppress cancer cell invasion by maintaining cell-cell junction integrity.

Approximately 90% of cancer-related deaths can be attributed to a tumour's ability to spread. We have identified CG7379, the fly orthologue of human ING1, as a potent invasion suppressor. ING1 is a type II tumour suppressor with well-established roles in the transcriptional regulation of genes that control cell proliferation, response to DNA damage, oncogene-induced senescence and apoptosis. Recent work suggests a possible role for ING1 in cancer cell invasion and metastasis, but the molecular mechanism underlying this observation is lacking. Our results show that reduced expression of CG7379 promotes invasion in vivo in Drosophila, reduces the junctional localization of several adherens and septate junction components, and severely disrupts cell-cell junction architecture. Similarly, ING1 knockdown significantly enhances invasion in vitro and disrupts E-cadherin distribution at cell-cell junctions. A transcriptome analysis reveals that loss of ING1 affects the expression of several junctional and cytoskeletal modulators, confirming ING1 as an invasion suppressor and a key regulator of cell-cell junction integrity.

European Resuscitation Council Guidelines 2021: Systems saving lives.

The European Resuscitation Council (ERC) has produced these Systems Saving Lives guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include chain of survival, measuring performance of resuscitation, social media and smartphones apps for engaging community, European Restart a Heart Day, World Restart a Heart, KIDS SAVE LIVES campaign, lower-resource setting, European Resuscitation Academy and Global Resuscitation Alliance, early warning scores, rapid response systems, and medical emergency team, cardiac arrest centres and role of dispatcher.

The multifarious regulation of the apical junctional complex.

Epithelial cells form highly organized polarized sheets with characteristic cell morphologies and tissue architecture. Cell-cell adhesion and intercellular communication are prerequisites of such cohesive sheets of cells, and cell connectivity is mediated through several junctional assemblies, namely desmosomes, adherens, tight and gap junctions. These cell-cell junctions form signalling hubs that not only mediate cell-cell adhesion but impact on multiple aspects of cell behaviour, helping to coordinate epithelial cell shape, polarity and function. This review will focus on the tight and adherens junctions, constituents of the apical junctional complex, and aims to provide a comprehensive overview of the complex signalling that underlies junction assembly, integrity and plasticity.

A Genetic Analysis of Tumor Progression in Drosophila Identifies the Cohesin Complex as a Suppressor of Individual and Collective Cell Invasion.

Metastasis is the leading cause of death for patients with cancer. Consequently it is imperative that we improve our understanding of the molecular mechanisms that underlie progression of tumor growth toward malignancy. Advances in genome characterization technologies have been very successful in identifying commonly mutated or misregulated genes in a variety of human cancers. However, the difficulty in evaluating whether these candidates drive tumor progression remains a major challenge. Using the genetic amenability of Drosophila melanogaster we generated tumors with specific genotypes in the living animal and carried out a detailed systematic loss-of-function analysis to identify conserved genes that enhance or suppress epithelial tumor progression. This enabled the discovery of functional cooperative regulators of invasion and the establishment of a network of conserved invasion suppressors. This includes constituents of the cohesin complex, whose loss of function either promotes individual or collective cell invasion, depending on the severity of effect on cohesin complex function.

Up to 206 Million People Reached and Over 5.4 Million Trained in Cardiopulmonary Resuscitation Worldwide: The 2019 International Liaison Committee on Resuscitation World Restart a Heart Initiative.

Sudden out-of-hospital cardiac arrest is the third leading cause of death in industrialized nations. Many of these lives could be saved if bystander cardiopulmonary resuscitation rates were better. "All citizens of the world can save a life-CHECK-CALL-COMPRESS." With these words, the International Liaison Committee on Resuscitation launched the 2019 global "World Restart a Heart" initiative to increase public awareness and improve the rates of bystander cardiopulmonary resuscitation and overall survival for millions of victims of cardiac arrest globally. All participating organizations were asked to train and to report the numbers of people trained and reached. Overall, social media impact and awareness reached up to 206 million people, and >5.4 million people were trained in cardiopulmonary resuscitation worldwide in 2019. Tool kits and information packs were circulated to 194 countries worldwide. Our simple and unified global message, "CHECK-CALL-COMPRESS," will save hundreds of thousands of lives worldwide and will further enable many policy makers around the world to take immediate and sustainable action in this most important healthcare issue and initiative.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations.

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

An apicobasal gradient of Rac activity determines protrusion form and position.

Each cell within a polarized epithelial sheet must align and correctly position a wide range of subcellular structures, including actin-based dynamic protrusions. Using in vivo inducible transgenes that can sense or modify Rac activity, we demonstrate an apicobasal gradient of Rac activity that is required to correctly form and position distinct classes of dynamic protrusion along the apicobasal axis of the cell. We show that we can modify the Rac activity gradient in genetic mutants for specific polarity proteins, with consequent changes in protrusion form and position and additionally show, using photoactivatable Rac transgenes, that it is the level of Rac activity that determines protrusion form. Thus, we demonstrate a mechanism by which polarity proteins can spatially regulate Rac activity and the actin cytoskeleton to ensure correct epithelial cell shape and prevent epithelial-to-mesenchymal transitions.

Time delays to reach dispatch centres in different regions in Europe. Are we losing the window of opportunity? - The EUROCALL study.

AIM: In out of hospital cardiac arrest (OHCA) the start of Cardiopulmonary Resuscitation (CPR) by a single rescuer may be delayed considerably if the total time (TT) to connect the telephone call to the Emergency Medical Communication Centre (EMCC) is prolonged. EUROCALL investigated the TT-EMCC and its components using different calling procedures. METHODS: This prospective, multicentre, randomised study was performed in April 2013. Telephone calls were randomly allocated to time of call, and to those connecting directly to the EMCC (1-step procedure) and those diverted before connecting to the EMCC (2-step procedure). RESULTS: Twenty-one EMCCs from 11 countries participated in the study. Time to first ringtone was similar between 1-step 3.7s (IQR 1.0-5.2) and 2-step calls 4.0s (IQR 2.4-5.2). For the 1878 1-step calls, the median TT-EMCC was 11.7s (IQR 8.7-18.5). For the 1550 2-step calls, the median time from first ringtone to first call-taker was 7s (IQR 4.6-11.9) and from first call-taker to EMCC was 18.7s (IQR 13.4-29.9). Median TT-EMCC was 33.2 s (IQR 24.7-46.1) and was significantly longer than the TT-EMCC observed with the 1-step procedure (P<0.0001). Significant differences existed among participating regions between and within different countries both for 1-step and 2-step procedures. CONCLUSION: TT-EMCC was significantly shorter in a 1-step procedure compared to a 2-step procedure. Regional differences existed between countries but also within countries. This may be relevant in cases of OHCA and other situations where patient outcome is critically time-dependent.

Glycosylated Notch and Cancer.

Glycosylation is one of the key components influencing several signaling pathways implicated in cell survival and growth. The Notch signaling pathway plays a pivotal role in numerous cell fate specifications during metazoan development. Both Notch and its ligands are repeatedly glycosylated by the addition of sugar moieties, such as O-fucose, O-glucose, or O-xylose, to bring about structural and functional changes. Disruption to glycosylation processes of Notch proteins result in developmental disorders and disease, including cancer. This review summarizes the importance and recent updates on the role of glycosylated Notch proteins in tumorigenesis and tumor metastasis.

The N-terminal and transmembrane domains of Commissureless are necessary for its function and trafficking within neurons.

Commissureless (Comm) is a novel transmembrane molecule necessary both for commissural axons to cross the midline of the Drosophila central nervous system and normal synaptogenesis. Comm is able to reduce cell surface levels of Roundabout (Robo), a receptor for the midline repellent Slit, on commissural axons and unknown inhibitors of synaptogenesis expressed on muscle cells. Comm is expressed dynamically and is found at the cell surface and within intracellular vesicles. Comm can bind Robo and when the proteins are co-expressed Robo is found co-localised with Comm intracellularly. Here we show that the ability of Comm to localise intracellularly and hence regulate Robo surface levels requires sequences in both the N-terminal and transmembrane domains. We also show that Comm can dimerise via its N-terminal domain. Furthermore, absence of the Comm N-terminal and transmembrane regions results in the protein being restricted to the neuron soma.

Attitudes of healthcare professionals involved in cardiology practice towards key points of contemporary guidelines on resuscitation.

Hellenic J Cardiol. 2014; 55: 378-385. At the request of the authors, the name of the second author of this Original Research article has been changed from Athanasios Patialakas to Athanasios Patialiakas.

Systematic review of the mechanisms driving effective blood flow during adult CPR.

BACKGROUND: High quality chest compressions is the most significant factor related to improved short-term and long-term outcome in cardiac arrest. However, considerable controversy exists over the mechanisms involved in driving blood flow. OBJECTIVES: The aim of this systematic review is to elucidate major mechanisms involved in effective compression-mediated blood flow during adult cardiopulmonary resuscitation (CPR). DESIGN AND SETTING: Systematic review of studies identified from the bibliographic databases of PubMed/Medline, Cochrane, and Scopus. SELECTION CRITERIA: All human and animal studies including information on the responsible mechanisms of compression-related blood flow. DATA COLLECTION AND ANALYSIS: Two reviewers (MG, TX) independently screened all potentially relevant titles and abstracts for eligibility, by using a standardized data-worksheet. MAIN RESULTS: Forty seven studies met the inclusion criteria. Because of the heterogeneity in outcome measures, quantitative synthesis of evidence was not feasible. Evidence was critically synthesized in order to answer the review questions, taking into account study heterogeneity and validity. The number of included studies per category is as follows: blood flow during chest compression, nine studies; blood flow during chest decompression, six studies; effect of chest compression on cerebral blood flow, eight studies; active compression-decompression CPR, 14 studies; and effect of ventilation on compression-related blood flow, 13 studies. CONCLUSION: The evidence so far is inconclusive regarding the major responsible mechanism in compression-related blood flow. Although both 'cardiac pump' and 'thoracic pump' have a key role, the effect of each mechanism is highly depended on other resuscitation parameters, such as positive pressure ventilation and compression depth.