Healthcare Professional's Knowledge of the Systemic ABCDE Approach: A Cross-Sectional Study.

Background and aim Assessing the knowledge of healthcare professionals regarding the Airway, Breathing, Circulation, Disability, and Exposure (ABCDE) approach is crucial since it prioritizes the initial assessment and treatment of patients who are critically ill, regardless of the underlying cause or their age. Since adherence requires knowledge, this study aimed to evaluate the knowledge level of the ABCDE approach among healthcare professionals. Methods This cross-sectional study among healthcare professionals was performed from April to August 2023 in Taif City, Saudi Arabia. The study included healthcare professionals employed in departments exposed to patients with critical illnesses and excluded those from other specialties and individuals from outside Taif City. Data was collected via Google Forms using a previously validated questionnaire designed to assess the ABCDE approach knowledge among healthcare professionals. Statistical analysis was conducted using IBM SPSS, version 26. Results The study included 242 healthcare professionals with a mean (SD) age of 35.77 (9.93) years. About half of the participants were female (52.5%) nurses (50.8%) and had been working in intensive care units (ICU) and neonate intensive care units (NICU) (41.4%). The mean (SD) of the participants' working experience was 9.28 (8.295) years. The overall mean test score was 52.94 % (SD 16.27). The mean knowledge score among males was significantly higher than females (56.37% vs. 49.85%, respectively) (p-value= 0.001). The mean knowledge score was significantly higher among medical specialists and residents (63.308% and 55.67%) than among nurses (46.34%) (p-value <0.001). Attending an advanced trauma life support course and theoretical lecture significantly impacted the total knowledge score among the participants (p-values= 0.001 and <0.001, respectively). The total knowledge significantly increased with age (r: 0.265, p-value <0.001). Years of experience correlated with total knowledge score; with increasing years of experience, the total knowledge was significantly increased (r: 0.248, p-value <0.001). Conclusion The ABCDE approach is a valuable tool for the initial examination and treatment of patients in acute medical and surgical emergencies. The findings indicate that there is a need for further awareness programs and training on the ABCDE approach, as the total knowledge score among healthcare professionals was found to be suboptimal. Further research is needed to assess the association between knowledge level and clinical performance in different healthcare settings within Saudi Arabia.

Missed opportunities for Intermittent Preventive Treatment of Malaria among pregnant women with the recommended number of antenatal care visits in Nigeria: Secondary Analysis of Malaria Indicator Survey 2021.

BACKGROUND AND OBJECTIVES: Missed opportunity (MO) for IPTp SP remains high in Nigeria even among pregnant women with four or more ANC visits. We assessed the current MO rate and its predictors, using data from the 2021 MIS. METHODS: We carried out a secondary analysis of data of women who had at least one live birth and at least 4 ANC visits. Bivariate analyses assessed the relationship between socio-demographic characteristics, type of ANC facility, type of ANC provider, knowledge of malaria prevention, awareness about IPT, and missed opportunity using the Chi-square test. Multivariate analyses were presented as odd ratios at 95% CI, (P value <0.05). RESULTS: Nearly half (47%) had only primary education or none at all. About 30% were poor. Most had their 1st visit ANC in the 2nd trimester (58%). The missed opportunity rate was 55%. Predictors included age 20 to 34 years [aOR 1.3(1.1-1.67)], being very poor [aOR 1.6(1.1-2.4)], late ANC (in 2nd or 3rd trimester) [aOR 0.57(0.4-0.89)], ignorance about malaria prevention [aOR 1.8(1.4-2.4)], ignorance about IPT [aOR 1.3(1.3-2.5)] and residence in the South South and North East [aOR 0.46(0.31-0.68)] regions. CONCLUSIONS: The missed opportunity was high. Place of residence, poor knowledge of malaria prevention and IPT use, late commencement of ANC, poverty, and young age (20 to 34 years) contributed to the burden. Recommendations include stressing the importance of IPT during health talks. Provision of cups and drinking water for the IPT DOT policy by the Government and partners. There is a need for further research to unravel the reasons for the higher MO rates in some regions.

CONTEXTE: Les opportunités manquées (OM) pour le TPIp SP restent élevées au Nigéria, même parmi les femmes enceintes ayant effectué quatre visites ou plus aux soins prénatals. Nous avons évalué le taux actuel d'OM et ses prédicteurs en utilisant les données de l'Enquête sur les Indicateurs du Paludisme de 2021. MÉTHODE: Nous avons réalisé une analyse secondaire des données des femmes ayant eu au moins une naissance en vie et au moins quatre visites de soins prénatals. Les analyses bivariées ont évalué la relation entre les caractéristiques sociodémographiques, le type d'installation de soins prénatals, le type de prestataire de soins prénatals, la connaissance de la prévention du paludisme, la sensibilisation à propos du TPIp, et les opportunités manquées en utilisant le test du chi-carré. Les analyses multivariées ont été présentées sous forme de cotes ajustées avec un intervalle de confiance de 95 % (valeur de p<0,05). RÉSULTATS: Près de la moitié (47 %) avaient seulement une éducation primaire ou n'en avaient pas du tout. Environ 30 % étaient pauvres. La plupart ont effectué leur 1ère visite prénatale au cours du 2ème trimestre (58 %). Le taux d'opportunités manquées était de 55 %. Les prédicteurs comprenaient l'âge de 20 à 34 ans [aOR 1,3 (1,1-1,67)], être très pauvre [aOR 1,6 (1,1-2,4)], début tardif des soins prénatals (au 2ème ou 3ème trimestre) [aOR 0,57 (0,4-0,89)], ignorance de la prévention du paludisme [aOR 1,8 (1,4-2,4)], ignorance du TPIp [aOR 1,3 (1,3-2,5)] et résider dans les régions du Sud-Sud et du Nord-Est [aOR 0,46 (0,31-0,68)]. CONCLUSION: Les opportunités manquées étaient élevées. Le lieu de résidence, la méconnaissance de la prévention du paludisme et de l'utilisation du TPIp, le début tardif des soins prénatals, la pauvreté et l'âge jeune (20 à 34 ans) ont contribué à cette charge. Les recommandations incluent de souligner l'importance du TPIp lors des entretiens de santé. La fourniture de gobelets et d'eau potable pour la politique de l'administration directe du TPI par le gouvernement et les partenaires. Il est nécessaire de poursuivre la recherche pour découvrir les raisons des taux plus élevés d'OM dans certaines régions. Mots-clés: Paludisme pendant la grossesse, traitement préventif intermittent, sulfadoxine-pyriméthamine, opportunité manquée, soins prénatals.

Discussion of "Optimal test procedures for multiple hypotheses controlling the familywise expected loss" by Willi Maurer, Frank Bretz, and Xiaolei Xun.

We provide commentary on the paper by Willi Maurer, Frank Bretz, and Xiaolei Xun entitled, "Optimal test procedures for multiple hypotheses controlling for the familywise expected loss." The authors provide an excellent discussion of the multiplicity problem in clinical trials and propose a novel approach based on a decision-theoretic framework that incorporates loss functions that can vary across multiple hypotheses in a family. We provide some considerations for the practical use of the authors' proposed methods as well as some alternative methods that may also be of interest in this setting.

Identification of Activation Isotopes in a CS-30 Cyclotron Vault.

A CS-30 cyclotron has been in operation at King Faisal Specialist Hospital and Research Center (KFSHRC) since 1982. The CS-30 cyclotron has been used to produce medical radioisotopes for positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Some of the nuclear reactions of radionuclide production are associated with the intense release of a wide range of fast neutrons. In this work, we investigated the radionuclides produced from neutron interactions with the cyclotron facility walls. Activation isotopes were determined by performing gamma ray spectrometry utilizing a high-purity germanium (HPGe) detector. The major radionuclides found were 152Eu, 154Eu, 134Cs, 65Zn and 60Co. Activation isotope accumulation had increased the dose rate inside the facility. The surface dose rates were measured at all of the surrounding walls. The maximum surface dose rate was found to be 1.2 µSv/h, which is much lower than the permissible occupational exposure of 15 µSv/h based daily 5 work hours.

The Impact of Privatization on Minority Faith Prison Chaplains in Canada.

Canadian federal prison chaplaincy underwent a major shift in 2013 when the provision of its services was privatized and outsourced to a single for-profit company. This article presents a summary of the experiences and concerns expressed by minority faith chaplains serving in federal correctional institutions following privatization. It is based on ten in-depth, semi-structured interviews with minority faith prison chaplains. The results show that minority faith federal prison chaplains are concerned about increased levels of bureaucratization that have compromised the quality of spiritual care available to prisoners, reductions in resources for chaplains, and increased levels of emotional exhaustion and frustration among themselves and fellow minority faith chaplains serving in Canadian correctional facilities.

High incidence of Plasmodium knowlesi malaria compared to other human malaria species in several hospitals in Malaysia.

Through the regional control programme, Malaysia has been successfully reducing the incidence of Plasmodium falciparum and Plasmodium vivax infections. However, the incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia especially Malaysian Borneo. The emergence of knowlesi infection has threatened the malaria elimination programme which the government aims to reduce the overall malaria infections by 2020. Unlike other benign human Plasmodium spp., P. knowlesi can cause fatal infections. The aim of this study was to determine the incidence and distribution of five human malaria parasites including P. knowlesi in Peninsular Malaysia and Malaysian Borneo. A total of 112 blood samples were collected from seven states and district hospitals in Peninsular Malaysia and Malaysian Borneo from year 2015 to 2016. The samples were examined by microscopy and further confirmed by nested PCR assay targeting 18S rRNA gene of Plasmodium spp. Following the nested PCR assays, a total of 54 (48.2%) samples were positive for P. knowlesi infections, 12 (10.7%) cases were positive for P. vivax infections, followed by 7 (6.3%) cases of P. falciparum and 4 (3.5%) cases of P. malariae. There were 3 cases (2.7%) of mixed infections (P. knowlesi/P. vivax). However, no cases were identified as P. ovale. A total of 32 (28.6%) cases were found as negative infections. LoopMediated Isothermal Amplification Assay (LAMP) was performed to confirm inconclusive results produced by microscopy and nested PCR. P. knowlesi showed the highest prevalence in Sarawak (n= 30), Sabah (n=13), Pulau Pinang (n=5) and Pahang (n=6). PCR and LAMP was not able to detect a large number of microscopy positive samples due to DNA degradation during storage and shipping. Among all the states involved in this study, the highest prevalence of P. knowlesi infection was found in Sabah and Sarawak.

Pulmonary arteriovenous malformations in children after the Kawashima procedure: Risk factors and midterm outcome.

BACKGROUND: Pulmonary arteriovenous malformations (PAVMs) are the major cause of progressive cyanosis in patients palliated with bidirectional cavopulmonary connection (BCPC). The aim of our study is to analyze the occurrence of PAVMs in patients after Kawashima procedure, to study the effect of total cavopulmonary connection (TCPC) on PAVMs, to evaluate the effect of axillary arteriovenous fistula (AAVF) creation on PAVMs, and to study the risk factors for PAVMs. METHODS: In this retrospective cohort study, all patients with left isomerism and azygous continuation of an interrupted inferior vena cava who underwent Kawashima procedure from July 2001 to December 2017 were included. RESULTS: Twenty.six patients after Kawashima procedure were included in our study. PAVMs were diagnosed in 12 patients (46%). Five of these 12 patients underwent TCPC with complete resolution of hypoxemia. Three patients underwent AAVF creation, 2 had complete resolution, while 1 had partial resolution of hypoxemia. Fourteen patients (54%) did not develop PAVMs. Nakata index below 267 mm2/m2and McGoon ratio below 1.9 predicted the development of PAVMs with high sensitivity and specificity. CONCLUSIONS: PAVMs represent a serious complication in patients who undergo Kawashima procedure. Small size of pulmonary arteries is an important risk factor for the development of PAVMs. Resolution of hypoxemia after TCPC completion supports the hepatic factor hypothesis. Early TCPC completion in these patients may help to avoid the development of PAVMs by restoring the hepatic factor. Resolution of hypoxemia after AAVF creation may support the lack of pulsatile flow hypothesis.

GSDME: A Potential Ally in Cancer Detection and Treatment.

Gasdermin E (GSDME) is an executioner of caspase-3 mediated regulated pyroptosis, and as such plays an important role in several cancers. Recent findings highlighted the potential of GSDME as a biomarker that can be implemented in cancer diagnosis, monitoring, and therapy.

High incidence of Plasmodium knowlesi malaria compared to other human malaria species in several hospitals in Malaysia

@# Through the regional control programme, Malaysia has been successfully reducing the incidence of Plasmodium falciparum and Plasmodium vivax infections. However, the incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia especially Malaysian Borneo. The emergence of knowlesi infection has threatened the malaria elimination programme which the government aims to reduce the overall malaria infections by 2020. Unlike other benign human Plasmodium spp., P. knowlesi can cause fatal infections. The aim of this study was to determine the incidence and distribution of five human malaria parasites including P. knowlesi in Peninsular Malaysia and Malaysian Borneo. A total of 112 blood samples were collected from seven states and district hospitals in Peninsular Malaysia and Malaysian Borneo from year 2015 to 2016. The samples were examined by microscopy and further confirmed by nested PCR assay targeting 18S rRNA gene of Plasmodium spp. Following the nested PCR assays, a total of 54 (48.2%) samples were positive for P. knowlesi infections, 12 (10.7%) cases were positive for P. vivax infections, followed by 7 (6.3%) cases of P. falciparum and 4 (3.5%) cases of P. malariae. There were 3 cases (2.7%) of mixed infections (P. knowlesi/P. vivax). However, no cases were identified as P. ovale. A total of 32 (28.6%) cases were found as negative infections. LoopMediated Isothermal Amplification Assay (LAMP) was performed to confirm inconclusive results produced by microscopy and nested PCR. P. knowlesi showed the highest prevalence in Sarawak (n= 30), Sabah (n=13), Pulau Pinang (n=5) and Pahang (n=6). PCR and LAMP was not able to detect a large number of microscopy positive samples due to DNA degradation during storage and shipping. Among all the states involved in this study, the highest prevalence of P. knowlesi infection was found in Sabah and Sarawak.

Loss of Asb2 Impairs Cardiomyocyte Differentiation and Leads to Congenital Double Outlet Right Ventricle.

Defining the pathways that control cardiac development facilitates understanding the pathogenesis of congenital heart disease. Herein, we identify enrichment of a Cullin5 Ub ligase key subunit, Asb2, in myocardial progenitors and differentiated cardiomyocytes. Using two conditional murine knockouts, Nkx+/Cre.Asb2fl/fl and AHF-Cre.Asb2fl/fl, and tissue clarifying technique, we reveal Asb2 requirement for embryonic survival and complete heart looping. Deletion of Asb2 results in upregulation of its target Filamin A (Flna), and concurrent Flna deletion partially rescues embryonic lethality. Conditional AHF-Cre.Asb2 knockouts harboring one Flna allele have double outlet right ventricle (DORV), which is rescued by biallelic Flna excision. Transcriptomic and immunofluorescence analyses identify Tgfß/Smad as downstream targets of Asb2/Flna. Finally, using CRISPR/Cas9 genome editing, we demonstrate Asb2 requirement for human cardiomyocyte differentiation suggesting a conserved mechanism between mice and humans. Collectively, our study provides deeper mechanistic understanding of the role of the ubiquitin proteasome system in cardiac development and suggests a previously unidentified murine model for DORV.

In vitro effect of autologous platelet-rich plasma on H2 O2 -induced oxidative stress in human spermatozoa.

BACKGROUND: Among new therapies emerging in the medical field, the use of platelet-rich plasma (PRP) in human reproduction has not yet been explored. OBJECTIVES: This study aimed at investigating the effect of autologous PRP on sperm parameters in the presence and absence of H2 O2 . MATERIALS AND METHODS: Semen samples were collected from 30 healthy men in their fourth decade attending Azoury IVF clinic. Spermatozoa, cultured in the presence or absence of 10 µM H2 O2 , were left untreated or treated with increasing concentrations of PRP (2, 5, and 10%). After 24-h incubation, ROS levels were assessed and sperm parameters were evaluated. RESULTS: Our results highlight the harmful effect of H2 O2 on sperm parameters, showing an increase in the percentage of reactive oxygen species (ROS)-positive cells, vacuolization, and sperm DNA fragmentation, and a decrease in progressive and total motility in the H2 O2 -treated group compared to non-stressed spermatozoa. When samples were treated with PRP, an improvement of the studied parameters was noted mainly with 2% PRP, thus regarded as the best concentration to achieve a positive effect on sperm parameters. Indeed, non-stressed and stressed spermatozoa treated with 2% PRP showed a significant increase in progressive and total motility, coupled with a decrease in ROS-positive cells, DNA fragmentation, vacuolization, and dead cells compared to the untreated group. In contrast, no significant difference in cell morphology was found between the two groups. Moreover, 2% PRP treatment enhanced sperm parameters and prevented cell death in H2 O2 -exposed spermatozoa as compared to freshly collected semen. DISCUSSION: We suggest that PRP because of its wide arrays of growth factors included in his alpha granules contributes to the inhibition of ROS through the antioxidant, anti-apoptotic activity. CONCLUSION: Autologous PRP improves the quality of the sperm, more so in the presence of an H2 O2 -induced OS.

Development of a bio-MEMS device for electrical and mechanical conditioning and characterization of cell sheets for myocardial repair.

Here we propose a bio-MEMS device designed to evaluate contractile force and conduction velocity of cell sheets in response to mechanical and electrical stimulation of the cell source as it grows to form a cellular sheet. Moreover, the design allows for the incorporation of patient-specific data and cell sources. An optimized device would allow cell sheets to be cultured, characterized, and conditioned to be compatible with a specific patient's cardiac environment in vitro, before implantation. This design draws upon existing methods in the literature but makes an important advance by combining the mechanical and electrical stimulation into a single system for optimized cell sheet growth. The device has been designed to achieve cellular alignment, electrical stimulation, mechanical stimulation, conduction velocity readout, contraction force readout, and eventually cell sheet release. The platform is a set of comb electrical contacts consisting of three-dimensional walls made of polydimethylsiloxane and coated with electrically conductive metals on the tops of the walls. Not only do the walls serve as a method for stimulating cells that are attached to the top, but their geometry is tailored such that they are flexible enough to be bent by the cells and used to measure force. The platform can be stretched via a linear actuator setup, allowing for simultaneous electrical and mechanical stimulation that can be derived from patient-specific clinical data.

Sortilin gates neurotensin and BDNF signaling to control peripheral neuropathic pain.

Neuropathic pain is a major incurable clinical problem resulting from peripheral nerve trauma or disease. A central mechanism is the reduced expression of the potassium chloride cotransporter 2 (KCC2) in dorsal horn neurons induced by brain-derived neurotrophic factor (BDNF), causing neuronal disinhibition within spinal nociceptive pathways. Here, we demonstrate how neurotensin receptor 2 (NTSR2) signaling impairs BDNF-induced spinal KCC2 down-regulation, showing how these two pathways converge to control the abnormal sensory response following peripheral nerve injury. We establish how sortilin regulates this convergence by scavenging neurotensin from binding to NTSR2, thus modulating its inhibitory effect on BDNF-mediated mechanical allodynia. Using sortilin-deficient mice or receptor inhibition by antibodies or a small-molecule antagonist, we lastly demonstrate that we are able to fully block BDNF-induced pain and alleviate injury-induced neuropathic pain, validating sortilin as a clinically relevant target.

Bioresorbable electrospun gelatin/polycaprolactone nanofibrous membrane as a barrier to prevent cardiac postoperative adhesion.

Post-cardiac surgical sternal and epicardial adhesions increase the risk and complexity of cardiac re-operative surgeries, which represent a significant challenge for patients with the congenital cardiac disease. Bioresorbable membranes can serve as barriers to prevent postoperative adhesions. Herein, we fabricated a bioresorbable gelatin/polycaprolactone (GT/PCL) composite membrane via electrospinning. The membrane was characterized in terms of morphology, mechanical properties, and biocompatibility. We then evaluated its efficacy as a physical barrier to prevent cardiac operative adhesions in a rabbit model. Our results showed that the membrane had a nanofibrous structure and was sturdy enough to be handled for the surgical procedures. In vitro studies with rabbit cardiac fibroblasts demonstrated that the membrane was biocompatible and inhibited cell infiltration. Further application of the membrane in a rabbit cardiac adhesion model revealed that the membrane was resorbed gradually and effectively resisted the sternal and epicardial adhesions. Interestingly, six months after the operation, the GT/PCL membrane was completely resorbed with simultaneous ingrowth of host cells to form a natural barrier. Collectively, these results indicated that the GT/PCL membrane might be a suitable barrier to prevent sternal and epicardial adhesions and might be utilized as a novel pericardial substitute for cardiac surgery. STATEMENT OF SIGNIFICANCE: Electrospinning is a versatile method to prepare nanofibrous membranes for tissue engineering and regenerative medicine applications. However, with the micro-/nano-scale structure and high porosity, the electrospun membrane might be an excellent candidate as a barrier to prevent postoperative adhesion. Here we prepared an electropun GT/PCL nanofibrous membrane and applied it as a barrier to prevent sternal and epicardial adhesions. Our results showed that the membrane had sufficient mechanical strength, good biocompatibility, and effectively resisted the sternal and epicardial adhesions. What's more, the membrane was bioresorbable and allowed simultaneous ingrowth of host cells to form a natural barrier. We believe that the current will inspire more research on nanomaterials to prevent postoperative adhesion applications.

Metabolic Maturation of Human Pluripotent Stem Cell-Derived Cardiomyocytes by Inhibition of HIF1α and LDHA.

RATIONALE: Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) are a readily available, robustly reproducible, and physiologically appropriate human cell source for cardiac disease modeling, drug discovery, and toxicity screenings in vitro. However, unlike adult myocardial cells in vivo, hPSC-CMs cultured in vitro maintain an immature metabolic phenotype, where majority of ATP is produced through aerobic glycolysis instead of oxidative phosphorylation in the mitochondria. Little is known about the underlying signaling pathways controlling hPSC-CMs' metabolic and functional maturation. OBJECTIVE: To define the molecular pathways controlling cardiomyocytes' metabolic pathway selections and improve cardiomyocyte metabolic and functional maturation. METHODS AND RESULTS: We cultured hPSC-CMs in different media compositions including glucose-containing media, glucose-containing media supplemented with fatty acids, and glucose-free media with fatty acids as the primary carbon source. We found that cardiomyocytes cultured in the presence of glucose used primarily aerobic glycolysis and aberrantly upregulated HIF1α (hypoxia-inducible factor 1α) and its downstream target lactate dehydrogenase A. Conversely, glucose deprivation promoted oxidative phosphorylation and repressed HIF1α. Small molecule inhibition of HIF1α or lactate dehydrogenase A resulted in a switch from aerobic glycolysis to oxidative phosphorylation. Likewise, siRNA inhibition of HIF1α stimulated oxidative phosphorylation while inhibiting aerobic glycolysis. This metabolic shift was accompanied by an increase in mitochondrial content and cellular ATP levels. Furthermore, functional gene expressions, sarcomere length, and contractility were improved by HIF1α/lactate dehydrogenase A inhibition. CONCLUSIONS: We show that under standard culture conditions, the HIF1α-lactate dehydrogenase A axis is aberrantly upregulated in hPSC-CMs, preventing their metabolic maturation. Chemical or siRNA inhibition of this pathway results in an appropriate metabolic shift from aerobic glycolysis to oxidative phosphorylation. This in turn improves metabolic and functional maturation of hPSC-CMs. These findings provide key insight into molecular control of hPSC-CMs' metabolism and may be used to generate more physiologically mature cardiomyocytes for drug screening, disease modeling, and therapeutic purposes.

Loss of Ccbe1 affects cardiac-specification and cardiomyocyte differentiation in mouse embryonic stem cells.

Understanding the molecular pathways regulating cardiogenesis is crucial for the early diagnosis of heart diseases and improvement of cardiovascular disease. During normal mammalian cardiac development, collagen and calcium-binding EGF domain-1 (Ccbe1) is expressed in the first and second heart field progenitors as well as in the proepicardium, but its role in early cardiac commitment remains unknown. Here we demonstrate that during mouse embryonic stem cell (ESC) differentiation Ccbe1 is upregulated upon emergence of Isl1- and Nkx2.5- positive cardiac progenitors. Ccbe1 is markedly enriched in Isl1-positive cardiac progenitors isolated from ESCs differentiating in vitro or embryonic hearts developing in vivo. Disruption of Ccbe1 activity by shRNA knockdown or blockade with a neutralizing antibody results in impaired differentiation of embryonic stem cells along the cardiac mesoderm lineage resulting in a decreased expression of mature cardiomyocyte markers. In addition, knockdown of Ccbe1 leads to smaller embryoid bodies. Collectively, our results show that CCBE1 is essential for the commitment of cardiac mesoderm and consequently, for the formation of cardiac myocytes in differentiating mouse ESCs.

MicroRNA-425 and microRNA-155 cooperatively regulate atrial natriuretic peptide expression and cGMP production.

AIMS: Atrial natriuretic peptide (ANP), secreted primarily by atrial cardiomyocytes, decreases blood pressure by raising cyclic 3',5'-guanosine monophosphate (cGMP) levels and inducing vasorelaxation, natriuresis, and diuresis. Raising the level of ANP has been shown to be an effective treatment for hypertension. To advance the future development of an anti-microRNA (miR) approach to increasing expression of ANP, we investigated the regulation of NPPA expression by two miRs: miR-425 and miR-155. We examined whether miR-425 and miR-155 have an additive effect on the expression and function of ANP. METHODS AND RESULTS: Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) were transfected with miR-425, miR-155, or a combination of the two miRs. Two days later, NPPA expression was measured using real time qPCR. Each of the miRs decreased NPPA expression over a wide range of concentrations, with a significant reduction at concentrations as low as 1 nM. The combination of miR-425 and miR-155 reduced NPPA expression to a greater extent than either miR-425 or miR-155 alone. An in vitro assay was developed to study the potential biological significance of the miR-induced decrease in NPPA expression. The cooperative effect of miR-425 and miR-155 on NPPA expression was associated with a significant decrease in cGMP levels. CONCLUSIONS: These data demonstrate that miR-425 and miR-155 regulate NPPA expression in a cooperative manner. Targeting both miRNAs with anti-miRs (possibly at submaximal concentrations) might prove to be a more effective strategy to modulate ANP levels, and thus blood pressure, than targeting either miRNA alone.