The cerebral endothelium is an active interface between blood and the central nervous system. In addition to being a physical barrier between the blood and the brain, the endothelium also actively regulates metabolic homeostasis, vascular tone and permeability, coagulation, and movement of immune cells. Being part of the blood–brain barrier, endothelial cells of the brain have specialized morphology, physiology, and phenotypes due to their unique microenvironment. Known cardiovascular risk factors facilitate cerebral endothelial dysfunction, leading to impaired vasodilation, an aggravated inflammatory response, as well as increased oxidative stress and vascular proliferation. This culminates in the thrombo-inflammatory response, an underlying cause of ischemic stroke and cerebral small vessel disease (CSVD). These events are further exacerbated when blood flow is returned to the brain after a period of ischemia, a phenomenon termed ischemia-reperfusion injury. Purinergic signaling is an endogenous molecular pathway in which the enzymes CD39 and CD73 catabolize extracellular adenosine triphosphate (eATP) to adenosine. After ischemia and CSVD, eATP is released from dying neurons as a damage molecule, triggering thrombosis and inflammation. In contrast, adenosine is anti-thrombotic, protects against oxidative stress, and suppresses the immune response. Evidently, therapies that promote adenosine generation or boost CD39 activity at the site of endothelial injury have promising benefits in the context of atherothrombotic stroke and can be extended to current CSVD known pathomechanisms. Here, we have reviewed the rationale and benefits of CD39 and CD39 therapies to treat endothelial dysfunction in the brain.
Stroke survivors report significant levels of psychological distress post stroke. To date, most studies conducted have focused on the relationship between psychological stress and functional outcomes in the acute phase of stroke. However, no studies had considered the role of stress over the chronic phase, where stress may continue to exert negative effects on cognitive and psychological processes. Further, the role of potentially modulatory variables, such as psychological resilience, on stroke outcomes has been understudied. The purpose of this study was to consider the relationships between stress and resilience with functional outcomes in long-term survivors of stroke. People (N = 70) who had experienced a stroke between 5 months and 28 years ago were included in the cross-sectional study, along with age-matched controls (N = 70). We measured stress using both the Perceived Stress Scale and biological markers, and resilience using both the Brief Resilience Scale and the Connor-Davidson Resilience Scale. Stroke outcomes were assessed using the Stroke Impact Scale. We found that, compared with age-matched controls, stroke survivors reported greater levels of perceived stress, and lower levels of resilience. In stroke survivors, both perceived stress and resilience were independently associated with stroke outcomes in linear regression models. In particular, these relationships were observed for cognitive outcomes including mood, memory, and communication. The association between stress and stroke outcome did not differ across time post stroke. Given that resilience is a modifiable psychological construct, future research may consider whether strategies directed at enhancing resilience may improve recovery from stroke. Australia and New Zealand Clinical Trials Registry: ACTRN12617000736347.
1 January 2014 in Clinical Hemorheology and Microcirculation
Erythrocyte aggregation has been consistently associated with insulin resistance, central obesity and hypertension in the literature. Oxidative stress and chronic inflammation are almost always present in metabolic syndrome (MetS). Prooxidants and adipocytokines generated in MetS alter erythrocyte morphology, decrease erythrocyte deformability and increase whole blood viscosity (WBV). Increased WBV has been attributed to erythrocyte aggregation which in turn is greatly influenced by other rheological parameters, including its membrane surface charge and plasma fibrinogen concentration. The interplay of hemorheological factors, oxidative stress and inflammation has a detrimental effect in MetS due to the gross disturbance in microcirculation. The hemodynamic aspect of MetS needs further research and exploration.
The study of erythrocyte morphology is of great importance in the field of hemorheology as the deformability of the circulating cells has a fundamental influence on the rheological properties of the blood. Diabetes mellitus, hypertension, dyslipidemia and obesity (mostly central obesity) are the major components of metabolic syndrome. In this review, we focus on the changes in erythrocyte morphology in different components of metabolic syndrome and also discuss the erythrocyte morphology in regards to oxidative stress - a common state of chronic diseases. This article also addresses the problem of inconsistency in the use of nomenclature and technique to identify the abnormal morphology and we recommend the use of standard terminology by all authors.
Community health workers, also known as health extension workers (HEWs), play an important role in health promotion. This study evaluates HEWs’ knowledge, attitude, and self-efficacy for non-communicable diseases (NCD) health promotion. HEWs (n = 203) completed a structured questionnaire on knowledge, attitude, behaviour, self-efficacy and NCD risk perception. Regression analysis was used to determine the association between self-efficacy and NCD risk perception with knowledge (high, medium, low), attitude (favourable/unfavourable) and physical activity (sufficient/insufficient). HEWs with higher self-efficacy were more likely to have high NCD knowledge (AOR: 2.21; 95% CI: 1.21. 4.07), favourable attitude towards NCD health promotion (AOR: 6.27; 95% CI: 3.11. 12.61) and were more physically active (AOR: 2.27; 95% CI: 1.08. 4.74) than those with lower self-efficacy. HEWs with higher NCD susceptibility (AOR: 1.89; 95% CI: 1.04. 3.47) and perceived severity (AOR: 2.69; 95% CI: 1.46, 4.93) had higher odds of NCD knowledge than their counterparts. Moreover, sufficient physical activity was influenced by HEWs’ perceived NCD susceptibility and perceived benefits of lifestyle change. Therefore, HEWs need to adopt healthy lifestyle choices to become effective role models for the community. Our findings highlight the need to include a healthy lifestyle when training HEWs, which might increase self-efficacy for NCD health promotion.