Transcriptional profile of c-kit positive cardiac stem-progenitor cells (c-kitpos eCSCs) isolated from the four chambers of the adult human heart

Introduction: Our findings and those of others show that the adult myocardium, including human, harbours a population of resident (endogenous) cardiac stem cells (eCSCs). They express the stem cell factor receptor c-kit, are distributed throughout the myocardium, are clonogenic, self-renewing and multi-potent, in that they differentiate into the 3 main cardiac lineages; cardiomyocytes, smooth muscle and endothelial cells in vitro and in vivo. The objective of this study is to determine whether c-kitpos eCSCs isolated from the different cardiac chambers have a distinct transcriptional profile depending on the chamber of origin. Methods: Pieces of myocardium have been obtained from all the 4 chambers of the adult human heart. All patients were fully consented before undergone open heart surgery. They were suffered of various cardiac pathologies such as ischemic heart disease, aortic, mitral and tricuspid valve insufficiency or stenosis, and various aortic pathologies. Ethical approval for these procedures has been given by NREC (08/H1306/91).c-kitpos eCSCs were isolated by enzymatic digestion and purified by Magnetic Activated Cell Sorting (MACS) from samples taken from the right and left atria (RA, LA), right and left ventricle (RV, LV) of the adult human heart. mRNA was isolated using Qiagen® mRNA kit, and reverse transcribed using first strand cDNA synthesis with random hexamers. qRT-PCR was performed using SYBR Green on a MyIQ thermocycler Bio-Rad® of specific genes representative of the primary and secondary heart field, and the developmental program of their chamber of origin. Results: c-kitpos eCSCs isolated from 15 human samples (5LA, 1RV, 4LV, 5RA) were processed. c-kitpos eCSCs are distributed throughout the human myocardium and in all 4 chambers of the heart. Transmitted light microscopic observations of c-kitpos eCSCs revealed that the c-kitpos cells from the human biopsies were generally small and rounded, consistent with a stable c-kitpos eCSCs phenotype, regardless of the chamber of origin. The eCSCs c-kitpos cells could be cultured under hypoxic conditions between 7 and 12 days to attain full confluency. Expression of transcripts for c-kit, Foxh1, Hand1, Hand2, Pitx2, Tbx5, Tbx20, Hrt1, Hrt2, Fgf8, Fgf10, and Isl1 were found at differential levels in c-kitpos CSCs isolated from the four cardiac chambers. Conclusion: This study is the first to show that c-kitpos eCSCs derived from human adult cardiac samples, do not appear to have a ‘chamber-specific’ transcript footprint, and are therefore potentially interchangeable between cardiac chambers, raising the potential of their therapeutic application

NO formation in nucleus tractus solitarii attenuates pressor response evoked by skeletal muscle afferents

Li, Jianhua, and Jeffrey T. Potts. NO formation in nucleus tractus solitarii attenuates pressor response evoked by skeletal muscle afferents. Am J Physiol Heart Circ Physiol 280: H2371-H2379, 2001.-We have previously shown that static muscle contraction induces the expression of c-Fos protein in neurons of the nucleus tractus solitarii (NTS) and that some of these cells were codistributed with neuronal NADPH-diaphorase [nitric oxide (NO) synthase]-positive fibers. In the present study, we sought to determine the role of NO in the NTS in mediating the cardiovascular responses elicited by skeletal muscle afferent fibers. Static contraction of the triceps surae muscle was induced by electrical stimulation of the L7 and S1 ventral roots in anesthetized cats. Muscle contraction during microdialysis of artificial extracellular fluid increased mean arterial pressure (MAP) and heart rate (HR) 51 Ϯ 9 mmHg and 18 Ϯ 3 beats/min, respectively. Microdialysis of L-arginine (10 mM) into the NTS to locally increase NO formation attenuated the increases in MAP (30 Ϯ 7 mmHg, P Ͻ 0.05) and HR (14 Ϯ 2 beats/min, P Ͼ 0.05) during contraction. Microdialysis of D-arginine (10 mM) did not alter the cardiovascular responses evoked by muscle contraction. Microdialysis of N G -nitro-L-arginine methyl ester (2 mM) during contraction attenuated the effects of Larginine on the reflex cardiovascular responses. These findings demonstrate that an increase in NO formation in the NTS attenuates the pressor response to static muscle contraction, indicating that the NO system plays a role in mediating the cardiovascular responses to static muscle contraction in the NTS. cardiovascular responses; static muscle contraction; blood pressure; heart rate; microdialysis; L-arginine; L-NAME STUDIES HAVE DEMONSTRATED that nitric oxide (NO) synthase (NOS) is localized in discrete medullary areas (41) involved in cardiovascular regulation The evidence that the muscle afferents terminate in several laminae of the spinal cord as well as ascending to terminate in the NTS has been shown by neuroanatomic tracing studies MATERIALS AND METHODS General Surgical Preparation Experiments were performed on 25 anesthetized cats of either sex weighing 3.4-5.5 kg. The animals were anesthetized by inhalation of a halothane-oxygen mixture (2-3%). An endotracheal tube was inserted into the trachea via a tracheotomy to maintain an open airway, and the jugular vein and carotid artery were catheterized for drug administration and measurement of ABP, respectively. Anesthesia was then maintained with a mixture of ␣-chloralose (80 mg/kg) and urethane (200 mg/kg) injected intravenously. Throughout the experiment, supplemental ␣-chloralose (15 mg/kg iv) was given if the cats exhibited a corneal reflex or if they withdrew a limb in response to a noxious stimulus

NHS health checks: a cross- sectional observational study on equity of uptake and outcomes

Background The National Health Checks programme aims to reduce the incidence of cardiovascular diseases and health inequalities in England. We assessed equity of uptake and outcomes from NHS Health Checks in general practices in Bristol, UK. Methods A cross-sectional study using patient-level data, from 38 general practices. We descriptively analysed the socioeconomic status (SES) of patients invited and the SES and ethnicity of those attending. Logistic regression was used to test associations between invitation and attendance, with population characteristics. Results Between June 2010 to October 2014, 31,881 patients were invited, and 13,733 NHS Health Checks completed. 47% of patients invited from the three least and 39% from the two most-deprived index of multiple deprivation quintiles, completed a Check. Proportions of invited patients, by ethnicity were 64% non-black and Asian and 31% black and Asian. Men were less likely to attend than women (OR 0.73, 95% confidence interval 0.67 to 0.80), as were patients ≤ 49 compared to ≥ 70 years (OR 0.40, 95% confidence interval 0.65 to 0.83). After controlling for SES and population characteristics, compared to patients with low CVD risk, high risk patients were more likely to be prescribed cardiovascular drugs (OR 6.2, 95% confidence interval 4.51 to 8.40). Compared to men, women (OR 01.18, 95% confidence interval 1.03 to 1.35) were more likely to be prescribed cardiovascular drugs, as were those ≤ 49 years (50–59 years, OR 1.42, 95% confidence intervals 1.13–1.79, 60–69 years, OR 1.60, 95% confidence intervals, 1.22–2.10, ≥ 70 years, OR 1.64, 95% confidence intervals, 1.14 to 2.35). Controlling for population characteristics, the following groups were most likely to be referred to lifestyle services: younger women (OR 2.22, 95% CI 1.69 to 2.94), those in the most deprived IMD quintile (OR 3.22, 95% CI 1.63 to 6.36) and those at highest risk of CVD (OR, 2.77, 95% CI 1.91 to 4.02). Conclusions We found no statistically significant evidence of inequity in attendance for an NHS Health Check by SES. Being older or a woman were associated with better attendance. Targeting men, younger patients and ethnic minority groups may improve equity in uptake for NHS Health Checks

Financial considerations in the conduct of multi-centre randomised controlled trials: evidence from a qualitative study.

National Coordinating Centre for Research Methodology; Medical Research Council, UK Department of Health; Chief Scientist OfficeNot peer reviewedPublisher PD

Developing theory and practice: Creation of a Community of Practice through Action Research produced excellence in stroke care

The study was funded by a grant from the Special Trustees of the Trust. Copyright @ 2010 Informa UK, Ltd.This article has been made available through the Brunel Open Access Publishing Fund.This article has been made available through the Brunel Open Access Publishing Fund.Much emphasis is placed on expert knowledge like evidence-based stroke guidelines, with insufficient attention paid to processes required to translate this into delivery of everyday good care. This paper highlights the worth of creating a Community of Practice (CoP) as a means to achieve this. Drawing on findings from a study conducted in 2000/2002 of processes involved in establishing a nationally lauded high quality Stroke Unit, it demonstrates how successful development of a new service was linked to creation of a CoP. Recent literature suggests CoPs have a key in implementing evidence-based practice; this study supports this claim whilst revealing for the first time the practical knowledge and skills required to develop this style of working. Findings indicate that participatory and democratic characteristics of Action Research are congruent with the collaborative approach required for developing a CoP. The study is an exemplar of how practitioner researchers can capture learning from changing practice, thus contributing to evidence-based healthcare with theoretical and practical knowledge. Findings are relevant to those developing stroke services globally but also to those interested in evidencebased practice.This article is available through the Brunel Open Access Publishing Fund