Comparative effects of propranolol, timolol and metoprolol on myocardial infarct size after experimental coronary artery occlusion

The effects of equiblocking doses of three beta-adrenergic blocking agents, propranolol, timolol and metoprolol, on myocardial infarct size were evaluated in 28 dogs after acute experimental coronary artery occlusion. Heart rate, arterial pressure and arterial free fatty acid concentration were measured in an attempt to evaluate their effects on the extent of myocardial injury. The zone at risk of infarction in each dog 1 minute after left anterior coronary artery occlusion was assessed by injecting highly radioactive albumin microspheres into the left atrium, and the hypoperfused zone was determined by autoradiography.After 15 minutes, the dogs were randomized into four groups: control dogs (n = 7), propranolol-treated dogs (1.2 mg/kg intravenously, n = 7), timolol-treated dogs (0.2 mg/kg intravenously, n = 7) and metoprolol-treated dogs (1.2 mg/kg intravenously, n = 7). After 6 hours, the dogs were killed. The left ventricle was sliced and stained with triphenyl-tetrazolium chloride for measurement of infarct size. The same slices were then autoradiographed for measurement of the hypoperfused zone. The percent of hypoperfused zone that evolved to infarction (the ratio of infarct size to hypoperfused zone) was 90.4 ± 1.9% in the control group, 72.4 ± 2.4% in the propranolol-treated dogs (p < 0.05 versus control group); 57.9 ± 4.4% in the timolol-treated dogs (p < 0.01 versus control group; p < 0.05 versus propranolol) and 54.4 ± 3.7% in the metoprolol-treated dogs (p < 0.01 versus control group; p < 0.05 versus propranolol).Thus, propranolol, timolol and metoprolol reduced myocardial infarct size in dogs by 20, 36 and 40%, respectively, after experimental coronary artery occlusion. Metoprolol and timolol protected the ischemic myocardium more effectively than did propranolol

Reduction of Experimental Myocardial Infarct Size by Corticosteroid Administration

The influence of the administration of pharmacologic doses of hydrocortisone on the extent and severity of acute myocardial ischemic injury and on subsequent necrosis after acute coronary occlusion was investigated in 28 dogs. In order to study acute myocardial injury, repeated epicardial electrocardiograms were recorded from 10 to 15 sites on the anterior surface of the left ventricle. Average ST segment elevation (ST) and the number of sites in which ST segment elevation exceeded 2 mV (NST), indices of the magnitude and extent of myocardial injury, respectively, were analyzed at 30 and 60 min after coronary occlusion. In the control group ST and NST did not change significantly in this time interval while in the treated group, which received 50 mg/kg hydrocortisone just after the 30 min recording, ST fell from 3.5+/-0.8 to 1.1+/-0.4 mV (P 2 mV) in the control group showed histologic changes compatible with early myocardial infarction in 96% of specimens, while this occurred only in 61% and 63% of specimens, respectively, in the treated groups, showing that over one third of the sites were protected from undergoing necrosis due to the intervening hydrocortisone treatment. Thus pharmacological doses of hydrocortisone prevent myocardial cells from progressing to ischemic necrosis even when administration is initiated 6 h after coronary occlusion

Not Just A Walk in The Park: methodological improvements for determining environmental justice implications of park access in New York City for the promotion of physical activity

The purpose of this study is to test the hypothesis that access to parks in New York City is not equitable across racial and ethnic categories. It builds on previous research that has linked access to parks and open space with increased physical activity, which in turn may reduce the risk for adverse health outcomes related to obesity. Systematic patterns of uneven access to parks might help to explain disparities in these health outcomes across sociodemographic populations that are not fully explained by individual-level risk factors and health behaviors, and therefore access to parks becomes an environmental justice issue. This study is designed to shed light on the “unpatterned inequities” of park distributions identified in previous studies of New York City park access. It uses a combination of network analysis and a cadastral-based expert dasymetric system (CEDS) to estimate the racial/ethnic composition of populations within a reasonable walking distance of 400m from parks. The distance to the closest park, number of parks within walking distance, amount of accessible park space, and number of physical activity sites are then evaluated across racial/ethnic categories, and are compared to the city-wide populations using odds ratios. The odds ratios revealed patterns that at first glance appear to contradict the notion of distributional inequities. However, discussion of the results points to the need for reassessing what is meant by “access” to more thoroughly consider the aspects of parks that are most likely to contribute to physical activity and positive health outcomes

The complexities of measuring access to parks and physical activity sites in New York City: a quantitative and qualitative approach

<p>Abstract</p> <p>Background</p> <p>Proximity to parks and physical activity sites has been linked to an increase in active behaviors, and positive impacts on health outcomes such as lower rates of cardiovascular disease, diabetes, and obesity. Since populations with a low socio-economic status as well as racial and ethnic minorities tend to experience worse health outcomes in the USA, access to parks and physical activity sites may be an environmental justice issue. Geographic Information systems were used to conduct quantitative and qualitative analyses of park accessibility in New York City, which included kernel density estimation, ordinary least squares (global) regression, geographically weighted (local) regression, and longitudinal case studies, consisting of field work and archival research. Accessibility was measured by both density of park acreage and density of physical activity sites. Independent variables included percent non-Hispanic black, percent Hispanic, percent below poverty, percent of adults without high school diploma, percent with limited English-speaking ability, and population density.</p> <p>Results</p> <p>The ordinary least squares linear regression found weak relationships in both the park acreage density and the physical activity site density models (R_a²= .11 and .23, respectively; AIC = 7162 and 3529, respectively). Geographically weighted regression, however, suggested spatial non-stationarity in both models, indicating disparities in accessibility that vary over space with respect to magnitude and directionality of the relationships (AIC = 2014 and -1241, respectively). The qualitative analysis supported the findings of the local regression, confirming that although there is a geographically inequitable distribution of park space and physical activity sites, it is not globally predicted by race, ethnicity, or socio-economic status.</p> <p>Conclusion</p> <p>The combination of quantitative and qualitative analyses demonstrated the complexity of the issues around racial and ethnic disparities in park access. They revealed trends that may not have been otherwise detectable, such as the spatially inconsistent relationship between physical activity site density and socio-demographics. In order to establish a more stable global model, a number of additional factors, variables, and methods might be used to quantify park accessibility, such as network analysis of proximity, perception of accessibility and usability, and additional park quality characteristics. Accurate measurement of park accessibility can therefore be important in showing the links between opportunities for active behavior and beneficial health outcomes.</p

Coronary Artery Reperfusion

The effects of coronary artery reperfusion 3 hr after coronary occlusion on contractile function and the development of myocardial damage at 24 hr was studied experimentally. In 14 control and 6 reperfused dogs, relationships between epicardial ST segment elevation 15 min after coronary occlusion and myocardial creatine phosphokinase activity (CPK) and histologic appearance 24 hr later were examined. The electrocardiograms were recorded from 10 to 15 sites on the left ventricular epicardium and transmural samples for CPK and histology were obtained from the same sites where epicardial electrocardiograms had been recorded. An inverse relation existed between ST segment elevation (mv) 15 min after occlusion and log CPK activity (IU/ mg of protein) 24 hr later, log CPK = - 0.06ST + 1.26. In dogs subjected to coronary artery reperfusion, there was significantly less CPK depression (log CPK = - 0.01ST + 1.31, [P < 0.01]) than that expected from the control group. In the control group 97% of specimens showing ST segment elevations over 2 mv at 15 min showed abnormal histology 24 hr later. In contrast, in the reperfused group 43% of sites exhibiting elevated ST segment at 15 min showed abnormal histology 24 hr later. In six additional dogs it was shown that the paradoxical movement of the left ventricular wall could be reversed within 1 hr of perfusion. Therefore, by enzymatic and histologic criteria, as well as by functional assessment, coronary artery reperfusion 3 hr after occlusion resulted in salvage of myocardial tissue

Medication deserts: survey of neighborhood disparities in availability of prescription medications

Background Only a small amount of research has focused on the relationship between socio-economic status (SES) and geographic access to prescription medications at community pharmacies in North America and Europe. To examine the relationship between a community’s socio-economic context and its residents’ geographic access to common medications in pharmacies, we hypothesized that differences are present in access to pharmacies across communities with different socio-economic environments, and in availability of commonly prescribed medications within pharmacies located in communities with different socio-economic status. Methods We visited 408 pharmacies located in 168 socio-economically diverse communities to assess the availability of commonly prescribed medications. We collected the following information at each pharmacy visited: hours of operation, pharmacy type, in-store medication availability, and the cash price of the 13 most commonly prescribed medications. We calculated descriptive statistics for the sample and fitted a series of hierarchical linear models to test our hypothesis that the in-stock availability of medications differs by the socio-economic conditions of the community. This was accomplished by modeling medication availability in pharmacies on the socio-economic factors operating at the community level in a socio-economically devise urban area. Results Pharmacies in poor communities had significantly higher odds of medications being out of stock, OR=1.24, 95% CI [1.02, 1.52]. There was also a significant difference in density of smaller, independent pharmacies with very limited stock and hours of operation, and larger, chain pharmacies in poor communities as compared to the middle and low-poverty communities. Conclusions The findings suggest that geographic access to a neighborhood pharmacy, the type of pharmacy, and availability of commonly prescribed medications varies significantly across communities. In extreme cases, entire communities could be deemed “medication deserts” because geographic access to pharmacies and the availability of the most prescribed medications within them were very poor. To our knowledge, this study is first to report on the relationship between SES and geographic access to medications using small area econometric analysis techniques. Our findings should be reasonably generalizable to other urban areas in North America and Europe and suggest that more research is required to better understand the relationship of socio-economic environments and access to medications to develop strategies to achieve equitable medication access

Integrating Social Determinants of Health With Treatment and Prevention: A New Tool to Assess Local Area Deprivation

We assessed the appropriate geographic scale to apply an area deprivation index (ADI), which reflects a geographic area’s level of socioeconomic deprivation and is associated with health outcomes, to identify and screen patients for social determinants of health. We estimated the relative strength of the association between the ADI at various geographic levels and a range of hospitalization rates by using age-adjusted odds ratios in an 8-county region of New York State. The 10-km local ADI estimates had the strongest associations with all hospitalization rates (higher odds ratios) followed by estimates at 20 km, 30 km, and the regional scale. A locally sensitive ADI is an ideal measure to identify and screen for the health care and social services needs and to advance the integration of social determinants of health with clinical treatment and disease prevention

Menstrual Product Insecurity Resulting From COVID-19‒Related Income Loss, United States, 2020.

To identify key effects of the pandemic and its economic consequences on menstrual product insecurity with implications for public health practice and policy. Study participants (n = 1496) were a subset of individuals enrolled in a national (US) prospective cohort study. Three survey waves were included (March‒October 2020). Menstrual product insecurity outcomes were explored with bivariate associations and logistic regression models to examine the associations between outcomes and income loss. Income loss was associated with most aspects of menstrual product insecurity (adjusted odds ratios from 1.34 to 3.64). The odds of not being able to afford products for those who experienced income loss was 3.64 times (95% confidence interval [CI] = 2.14, 6.19) that of those who had no income loss and 3.95 times (95% CI = 1.78, 8.79) the odds for lower-income participants compared with higher-income participants. Pandemic-related income loss was a strong predictor of menstrual product insecurity, particularly for populations with lower income and educational attainment. Provision of free or subsidized menstrual products is needed by vulnerable populations and those most impacted by pandemic-related income loss.( 2022;112(4):675-684. (https://doi.org/10.2105/AJPH.2021.306674)

Pranolium

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72226/1/j.1527-3466.1983.tb00447.x.pd