This study was designed to elicit women's perceptions of their illness experience with myocardial infarction for the purpose of exploring and describing the nature and meaning of this illness experience and its impact on everyday life. The phenomenological method, a type of qualitative research, was used to direct the study. The data were compiled through a series of semi-structured intensive interviews with eight women. The women were 36 to 71 years of age. Six of the women were married and living with their husbands. The women had been at home following discharge from hospital for 2 to 14 weeks. Data collection and data analysis proceeded simultaneously and data collection ceased once consistent themes were identified and validated and the data collected were sufficiently rich and in-depth. Women explain their illness experience with myocardial infarction as a loss phenomenon and the central and dominant loss within the heart attack experience for women is loss of predictability. Women's need for information following myocardial infarction is not met and lack of energy is a prominent feature in everyday life after a heart attack. Traditional sex role socialization sets the stage for potential problems in women's cardiac rehabilitation, especially in relation to support and role enactment. Physical rehabilitation is not a selected strategy to gain control over their loss experience for women with myocardial infarction. The findings and conclusions of this study suggest a number of implications for nursing practice. There is clear direction for family-centered nursing care in the rehabilitation of women with myocardial infarction to address potential problems in relation to support and role enactment. This study reinforces the value of using the concepts of loss and grief to care for patients with myocardial infarction. Also, this study indicates that, in planning nursing care for women with myocardial infarction, nurses should focus on Interventions to increase support, to meet patient and family educational needs, and to help women to anticipate normal physical and psychological responses to myocardial infarction. This study also has specific implications for the development of structured cardiac rehabilitation programmes addressing the special needs of women. In relation to nursing education, nurses must be prepared to assess, teach, and counsel patients with myocardial infarction and their families. Most importantly, this study directs nursing educators to provide course work in women's health issues to sensitize nurses to this field of study and to equip nurses with the understanding necessary to facilitate changes in women's health care. Implications for future research include further exploration of information needs, support, and strategies for control in relation to women with myocardial infarction. / Applied Science, Faculty of / Nursing, School of / Graduate

This qualitative study was designed to explore the experience of risk factor modification from the perspective of patients who had sustained an acute myocardial infarction. Research has shown that modification of coronary risk factors including stopping smoking, reducing hypercholesterolemia and obesity, reducing hypertension, developing a habit of regular exercise, and developing methods to modify the coronary-prone behavior pattern reduces morbidity and mortality due to coronary heart disease. The literature reviewed indicated that cardiac rehabilitation programs are generally structured to provide the patient with information on coronary artery disease. However, it has been shown that information alone may not be enough to ensure that changes in behavior occur. Since there was a scarcity of information on measures to assist patients to modify their coronary risk factors, and as the literature indicated that the experience of risk factor modification had not been explored from patients' perspectives, a phenomenological design was therefore selected as the methodology for this study. Data were collected through twelve in-depth interviews with six participants. A guide of semi-structured questions was used for the initial interview and additional questions were generated from the data themselves. The constant comparative method of data analysis enabled the researcher to construct an analytic framework which represented patients' perceptions of their experiences in risk factor modification. In this framework, the central theme of patients' experiences was gaining mastery over their risk behavior(s). Gaining mastery occurred in three phases: searching for attribution, acknowledging risk, and attaining control. In attaining control, various cognitive and behavioral strategies were identified which led to a delineation of measures that could be provided to assist other patients in modifying their coronary risk factors. The findings demonstrated that a unique perspective of risk factor modification has been provided by patients based on their own experiences. It was also shown that intervention, consisting of teaching, counseling, and support, is essential to each phase of this process. The implications of this study focus on the importance of intervention in both in-hospital and out-patient cardiac rehabilitation programs. Intervention to assist patients to develop and use those skills that will enable them to gain a sense of mastery over their risk behaviors is essential if an initial or recurrent myocardial infarction is to be prevented. Implications for nursing practice, education, and research are outlined in light of the research findings. / Applied Science, Faculty of / Nursing, School of / Graduate

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22314号 / 医博第4555号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 山下 潤, 教授 Shohab YOUSSEFIAN, 教授 湊谷 謙司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Original published work submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Medicine (Internal Medicine) 18 October, 2017. / The very first coronary artery balloon angioplasty is reported to have been performed by Gruntzig in 1977.1 Subsequently to this, over the past 40 years, there have been significant advances in coronary angiography and intervention. Coronary artery interventional techniques have evolved and improved significantly. There have been considerable device developments, new generation stents and novel antiplatelet therapy which have all proved to reduce the incidence of the primary periprocedural complications associated with percutaneous coronary intervention (PCI). [No abstract provided. Information taken from introduction] / LG2018

Myocardial infarction (MI), a late-stage event of many cardiovascular diseases (CVD), results in cardiomyocyte death, myeloid cell recruitment to promote cellular debris removal and excessive cardiac remodeling affecting architecture and function, which can ultimately lead to heart failure. Currently, the use of biomaterials to intervene on the hostile post-MI environment and promote myocardial healing is being investigated to restore cardiac function. It has been shown that an injectable collagen matrix improves cardiac repair by altering macrophage polarization, reducing cell death and enhancing angiogenesis, leading to a reduction in infarct size and improved cardiac function when delivered at 3 hours post-MI. MicroRNAs (miRNA) “fine tune” gene expression by negatively regulating the translational output of target messenger RNA (mRNA). As such, miRNAs present interesting therapeutic opportunities for the treatment of MI. However, the delivery of miRNA mimics and/or inhibitors can be complicated by degradation and off target effects. The objectives of this thesis were to determine how the matrix may regulate endogenous miRNAs and to explore the biomaterial’s ability to deliver therapeutic miRNAs. It was shown that matrix treatment of MI mouse hearts resulted in altered expression of 119 miRNAs, some of which had functions linked to the beneficial effects of matrix treatment. Of particular interest, miR-92a was down-regulated within the infarct and peri-infarct cardiac tissue 2 days after matrix treatment (delivered at 3-hours post-MI) compared to PBS treatment. In in vitro cultures, the matrix down-regulated miR-92a levels in macrophages but did not significantly alter miR-92a expression in endothelial cells, circulating angiogenic cells or fibroblasts. In addition, using an in vitro model system, it was shown that the matrix may have the potential to deliver functional therapeutic miRNAs to cells; however further experimental optimisation is required to confirm these results. Therefore, collagen matrix treatment may be a promising approach to regulate and/or deliver miRNAs for protecting the myocardial environment and improving function of the infarcted heart.

Background: Transplantation of marrow stromal cells (MSC) has been shown to improve heart perfusion and cardiac function after ischemia. Erythropoietin (EPO) is capable of inducing angiogenesis and inhibiting cell apoptosis. The aim of this study was to investigate the effect of EPO on the therapeutic potency of MSC transplantation in a rat model of myocardial infarction. Methods: MSC viability was detected by MTT andflow cytometry following culture in serum-free medium for 24 h with or without EPO. Release of vascular endothelial growth factor (VEGF) by MSC incubated with different doses of EPO was assayed using ELISA. Immediately after coronary ligation, autologous MSC (3 × 10 6 cells) were injected into the ischemic myocardium (MSC and MSC-EPO groups). EPO (3,000 U/kg body weight) was injected daily for 3 consecutive days starting 1 day prior to ligation. The same EPO dose was also injected for consecutive 3 days starting 15 days after surgery (EPO and MSC-EPO groups). Control animals were injected saline solution for the same time period. Cardiac function was assessed by echocardiography 2 and 21 days after surgery, respectively. Western blot and immunohistological assessments were performed to examine the effects of treatments. Results: In vitro, EPO inhibited MSC apoptosis induced by serum-free medium and increased vascular endothelial growth factor (VEGF) release by MSC. In vivo, cardiac infarct size was significantly smaller, cardiac function significantly improved, and capillary density obviously higher in the MSC and EPO groups than in the control group. Combined treatment with EPO infusion and MSC transplantation demonstrated a further decrease in infarct size, a further improvement in cardiac function, and a further increase in capillary density compared with MSC or EPO alone. Furthermore, a higher ratio of phosphorylated Akt to total Akt was measured by Western blot; Bcl-2 was upregulated and Bax was downregulated by immunohistochemistry in the MSC-EPO group compared to the other three groups. Conclusion: Transplantation of MSC combined with EPO infusion is superior to MSC monotherapy for angiogenesis and cardiac function recovery.

We postulated that combining erythropoietin (EPO) infusion with bone marrow mesenchymal stem cells (MSC) delivery may give better prognosis in a rat infarcted heart. Acute myocardial infarction (MI) model was developed by coronary artery ligation. Animals were grouped (n = 18) to receive intramyocardial injection of 30 μl saline solution without cells (EPO and control groups) or with 3 × 106 MSC from transgenic green fluorescent protein (GFP)+ male mice (MSC and MSC-EPO groups). The animals received either 5000 U/kg body weight EPO (EPO and MSC-EPO groups) or saline solution (MSC and control groups) for 7 days after MI. Cardiac functions were measured by echocardiography and cardiac tissue was harvested for immunohistological studies 3 weeks after surgery. We observed regeneration of MSC in and around the infarcted myocardium in MSC and MSC-EPO groups. Capillary density was markedly enhanced with significantly smaller infarct size and reduced fibrotic area in MSC-EPO group as compared with other three groups. A smaller left ventricular (LV) diastolic dimension and a higher LV fractional shortening were observed in MSC-EPO group than in other three groups. Transplantation of MSC combined with cytokine EPO is superior to either of the monotherapy approach for angiomyogenesis and cardiac function recovery.

Experiments were performed to test the postulate that exercise training (ExT) improves the blunted renal excretory response to acute volume expansion (VE), in part, by normalizing the neural component of the volume reflex typically observed in chronic heart failure (HF). Diuretic and natriuretic responses to acute VE were examined in sedentary and ExT groups of rats with either HF or sham-operated controls. Experiments were performed in anesthetized (Inactin) rats 6 wk after coronary ligation surgery. Histological data indicated that there was a 34.9 ± 3.0% outer and 42.5 ± 3.2% inner infarct of the myocardium in the HF group. Sham rats had no observable damage to the myocardium. In sedentary rats with HF, VE produced a blunted diuresis (46% of sham) and natriuresis (35% of sham) compared with sham-operated control rats. However, acute VE-induced diuresis and natriuresis in ExT rats with HF were comparable to sham rats and significantly higher than sedentary HF rats. Renal denervation abolished the salutary effects of ExT on renal excretory response to acute VE in HF. Since glomerular filtration rates were not significantly different between the groups, renal hemodynamic changes may not account for the blunted renal responses in rats with HF. Additional experiments confirmed that renal sympathetic nerve activity responses to acute VE were blunted in sedentary HF rats; however, ExT normalized the renal sympathoinhibition in HF rats. These results confirm an impairment of neurally mediated excretory responses to acute VE in rats with HF. ExT restored the blunted excretory responses as well as the renal sympathoinhibitory response to acute VE in HF rats. Thus the beneficial effects of ExT on cardiovascular regulation in HF may be partly due to improvement of the neural component of volume reflex. Copyright © 2006 the American Physiological Society.

Objective: Osteopontin (OPN), increased in the heart following myocardial infarction (MI), plays an important role in post-MI remodeling. Angiogenesis, an important feature of tissue repair, begins in the infarcted myocardium within 3 days post-MI. Here, the authors studied the role of OPN in myocardial angiogenesis using wild-type (WT) and OPN knockout (KO) mice. Results: Measurement of angiogenic response using Griffonia simplicifolia lectin-1 (GSL-1) staining indicated reduced capillary density in the infarcted region of the OPN KO hearts as compared to WT hearts 7 and 14 days post-MI. Arteriolar density was lower in OPN KO hearts 14 days post-MI. The number of CD31 positive cells was also lower in the infarcted region of the OPN KO hearts as compared to WT hearts 14 days post-MI. In contrast, capillary and arteriolar densities in the noninfarcted regions of OPN KO and WT hearts were not significantly different. In vivo myocardial angiogenesis measured using Matrigel implantation in the left ventricular myocardium indicated significant decrease in the percentage of vessel-like areas in the OPN KO vs. WT hearts. Furthermore, in vitro Matrigel tube formation assay demonstrated a significant decrease in total tube length in cardiac microvascular endothelial cells (CMECs) isolated from OPN KO hearts as compared to CMECs from WT hearts. Treatment of OPN KO CMECs with purified OPN protein significantly increased total tube length, while bovine serum albumin had no effect. Conclusion: Lack of OPN impairs myocardial angiogenic response, leading to adverse remodeling post-MI.