Varying Influences of Aldosterone on the Plasma Potassium Concentration in Blacks and Whites

BACKGROUND: Aldosterone acts to restrain the extracellular potassium (K+) concentration. Blacks have on average lower plasma aldosterone concentrations (PACs) than Whites. Whether this ethnic difference is associated with similar changes in the concentration of K+ is unclear. METHODS: Subjects were Blacks and Whites from an observational study of blood pressure regulation. PAC was known to be significantly lower in Blacks than Whites. We sought to test the hypothesis that the concentration of K+ remains constant despite variability in PAC. Initial enrollment took place in childhood in 1986. Some of the original enrollees were studied again in adulthood: 160 healthy Blacks and 271 healthy Whites (ages 5 to 39 years; all were studied as children and as adults). RESULTS: Plasma renin activity [a biomarker of angiotensin II and, more proximally, extracellular fluid volume (ECFV)] and PAC were lower in Blacks (P < 0.0354 and P < 0.001, respectively, for all ages). At the same time no ethnic difference in levels of K+ was observed regardless of age. Plasma K+ concentration and PAC associated differently based on ethnicity: PAC increased in Blacks by 1.5-2.0 and in Whites by 2.3-3.0 ng/dl per mmol/l increase in K+ (P < 0.001). CONCLUSIONS: Lower aldosterone levels in Blacks did not translate into higher K+ concentrations. We speculate that reaching the right concentration of K+ was an endpoint of aldosterone production in the presence of varying levels of ECFV and angiotensin II

Organizing the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST): National Institutes of Health, Health Care Financing Administration, and industry funding

The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) is a prospective, randomized, multicenter clinical trial of carotid endarterectomy (CEA) versus carotid artery stenting (CAS) as prevention for stroke in patients with symptomatic stenosis greater than or equal to 50%. CREST is sponsored by the US National Institute of Neurological Disorders and Stroke (NINDS) of the US National Institutes of Health (NIH), with additional support by a device manufacturer, and will provide data to the US Food and Drug Administration (FDA) for evaluation of a stent device. Because of budget constraints for CREST, Health Care Financing Administration (HCFA) reimbursement for hospital costs incurred by CREST patients will be essential. The involvement of academic scientists, industry, and three separate government agencies (NIH, FDA, HCFA) has presented many challenges in conducting the trial. A review of the pathways followed to meet these challenges may be helpful to others seeking to facilitate sharing of the costs and burdens of conducting innovative clinical research

Lung function, inflammation, and endothelin-1 in congenital heart disease-associated pulmonary arterial hypertension

Background-—Breathlessness is the most common symptom in people with pulmonary arterial hypertension and congenital heart disease (CHD-APAH), previously thought to be caused by worsening PAH, but perhaps also by inflammation and abnormalities of lung function. We studied lung function and airway inflammation in patients with CHD-APAH and compared the results with controls. Methods and Results-—Sixty people were recruited into the study: 20 CHD-APAH, 20 CHD controls, and 20 healthy controls. Spirometry, gas transfer, whole body plethysmography and lung clearance index, 6-minute walk distance, and medical research council dyspnea scoring were performed. Inflammatory markers and endothelin-1 levels were determined in blood and induced sputum. The CHD-APAH group had abnormal lung function with lung restriction, airway obstruction, and ventilation heterogeneity. Inverse correlations were shown for CHD-APAH between medical research council dyspnea score and percent predicted peak expiratory flow (r= 0.5383, P=0.0174), percent predicted forced expiratory flow rate at 50% of forced vital capacity (r= 0.5316, P=0.0192), as well as for percent predicted forced expiratory volume in 1 s (r= 0.6662, P=0.0018) and percent predicted forced vital capacity (r= 0.5536, P=0.0186). The CHD-APAH patients were more breathless with lower 6-minute walk distance (360 m versus 558 m versus 622 m, P=0.00001). Endothelin-1, interleukin (IL)-b, IL-6, IL-8, tumor necrosis factor a, and vascular endothelial growth factor were significantly higher in CHD-APAH than controls. Serum endothelin-1 for CHD-APAH correlated with airflow obstruction with significant negative correlations with percent predicted forced expiratory flow rate at 75% of forced vital capacity (r= 0.5858, P=0.0135). Conclusions-—Raised biomarkers for inflammation were found in CHD-APAH. Significant abnormalities in airway physiology may contribute to the dyspnea but are not driven by inflammation as assessed by circulating and sputum cytokines. A relationship between increased serum endothelin-1 and airway dysfunction may relate to its bronchoconstrictive properties. (J Am Heart Assoc. 2018;7:e007249. DOI: 10.1161/JAHA.117.007249.

In Stories We Trust: Studies of the Validity of Autobiographies

There is a dearth of research addressing the validity of life stories, or autobiographies. In part, this is because it is unclear how such data sources might be validated. This article recommends two differ-ent perspectives for obtaining evidence relevant to the validity of autobiographical data. A study is conducted from each of these perspectives, and multiple validity estimates are obtained in each in-vestigation. The construct validity of standard psychological constructs (e.g., assertiveness, trustwor-thiness) obtained in Study 1 from autobiographies was equal to that of standard instruments designed to assess these constructs. Evidence for the validity of life themes, extracted from autobi-ographies in Study 2, was also apparent. Because life histories, autobiographies, and case studies are relied on heavily in the practice of counseling psychology and are rapidly regaining popularity in scientific studies, these positive findings suggest the wisdom in this increasing use of life history data

In Stories We Trust: Studies of the Validity of Autobiographies

There is a dearth of research addressing the validity of life stories, or autobiographies. In part, this is because it is unclear how such data sources might be validated. This article recommends two differ-ent perspectives for obtaining evidence relevant to the validity of autobiographical data. A study is conducted from each of these perspectives, and multiple validity estimates are obtained in each in-vestigation. The construct validity of standard psychological constructs (e.g., assertiveness, trustwor-thiness) obtained in Study 1 from autobiographies was equal to that of standard instruments designed to assess these constructs. Evidence for the validity of life themes, extracted from autobi-ographies in Study 2, was also apparent. Because life histories, autobiographies, and case studies are relied on heavily in the practice of counseling psychology and are rapidly regaining popularity in scientific studies, these positive findings suggest the wisdom in this increasing use of life history data

National variation in United States sepsis mortality: a descriptive study

<p>Abstract</p> <p>Background</p> <p>The regional distribution of a disease may provide important insights regarding its pathophysiology, risk factors and clinical care. While sepsis is a prominent cause of death in the United States (US), few studies have examined regional variations with this malady. We identified the national variation in sepsis deaths in the US. We conducted a descriptive analysis of 1999-2005 national vital statistics data from the National Center for Health Statistics summarized at the state-level. We defined sepsis deaths as deaths attributed to an infection, classified according to the International Classification of Diseases, Version 10. We calculated national and state age-adjusted sepsis-attributed mortality rates.</p> <p>Results</p> <p>National age-adjusted sepsis mortality was 65.5 per 100,000 persons (95% CI: 65.8 - 66.0). State level sepsis mortality varied more than two-fold (range 41 to 88.6 per 100,000 persons; median 60.8 per 100,000, IQR 53.9-74.4 per 100,000). A cluster extending from the Southeastern to the mid-Atlantic US encompassed states with the highest sepsis mortality.</p> <p>Conclusions</p> <p>Sepsis mortality varies across the US. The states with highest sepsis mortality form a contiguous cluster in the Southeastern and mid-Atlantic US. These observations highlight unanswered questions regarding the characteristics and care of sepsis.</p

Computer-assisted diagnosis in the noninvasive evaluation of patients with suspected coronary artery disease

A microcomputer program called CADENZA, which employs Bayes' theorem to analyze and report the results of various clinical descriptors and noninvasive tests relative to the diagnosis of coronary artery disease, was evaluated in 1,097 consecutive patients without previous myocardial infarction. With this program, each patient was characterized by a probability for coronary artery disease, based on Framingham risk factor analysis, symptom characterization, electrocardiographic stress testing, cardiokymography, cardiac fluoroscopy, thallium perfusion scintigraphy and technetium equilibrium-gated blood pool scintigraphy. A total of 11,808 probability estimates derived from various combinations of the available observations were analyzed: 2,180 in 170 patients undergoing coronary angiography and 9,628 in 969 patients who completed a 1 year follow-up for coronary events.The predicted probability of disease correlated linearly with observed angiographic prevalence in the 170 patients who subsequently had coronary angiography (prevalence = [0.001 ± 0.011] + [0.966 ± 0.019] x probability). The difference between probability and prevalence averaged 3.1%, and the magnitude of this correlation was not affected by the type or amount of data analyzed. The prevalence of multivessel disease in these patients increased as a monotonic function of disease probability. Below a probability of 25%, single vessel disease was slightly more common than multivessel disease. Above a probability of 75%, multivessel disease predominated. In the 969 patients followed up for 1 year from the date of testing, the incidence of cardiac death and nonfatal infarction increased as a cubic function of disease probability (from approximately 0 to 8% per year for each). Above a probability of 90%, however, the standard deviation for predicting these events was wide.These data indicate that Bayes' theorem in general— and CADENZA in particular—is an accurate, clinically applicable means for quantifying the prevalence of angiographic coronary artery disease, the risk of multivessel disease and the incidence of morbid coronary events in the year after testing

Confirmation of SBS 1150+599A As An Extremely Metal-Poor Planetary Nebula

SBS 1150+599A is a blue stellar object at high galactic latitude discovered in the Second Byurakan Survey. New high-resolution images of SBS 1150+599A are presented, demonstrating that it is very likely to be an old planetary nebula in the galactic halo, as suggested by Tovmassian et al (2001). An H-alpha image taken with the WIYN 3.5-m telescope and its "tip/tilt" module reveals the diameter of the nebula to be 9.2", comparable to that estimated from spectra by Tovmassian et al. Lower limits to the central star temperature were derived using the Zanstra hydrogen and helium methods to determine that the star's effective temperature must be > 68,000K and that the nebula is optically thin. New spectra from the MMT and FLWO telescopes are presented, revealing the presence of strong [Ne V] lambda 3425, indicating that the central star temperature must be > 100,000K. With the revised diameter, new central star temperature, and an improved central star luminosity, we can constrain photoionization models for the nebula significantly better than before. Because the emission-line data set is sparse, the models are still not conclusive. Nevertheless, we confirm that this nebula is an extremely metal-poor planetary nebula, having a value for O/H that is less than 1/100 solar, and possibly as low as 1/500 solar.Comment: 19 pages, 6 figures. Accepted for publication in the Astronomical Journa

The Effect of Body Mass Index on Blood Pressure Varies by Race among Children

poster abstractThe effect of adiposity on blood pressure (BP) intensifies as children become obese, and black children tend to have greater body mass index (BMI) and higher BP than age-matched white children. But few studies have compared the magnitude of the effect of BMI on BP in obese black and white children. We used a novel analytic technique to examine the influence of age and BMI on BP in children seen at a hospital-based obesity clinic. The study sample included 821 overweight and obese children (age and sex adjusted BMI% ranged from 87% to 100%; 306 males, 515 females, 362 blacks, and 459 whites). The mean age of the study subjects was 11.72 ± 3.48 years, the mean BMI was 36.22 ± 8.51 kg/m2, and the mean systolic and diastolic BP were 109.36 ± 16.10 and 69.99 ± 10.48 mmHg, respectively. In comparison, blacks and whites were similar in age (11.89 vs 11.58; p=0.197); while black patients had higher BMI (37.32 vs 35.34 kg/m2; p=0.0010), and higher systolic BP% than whites (58.71 vs 50.72 mmHg; p=0.00062). Semiparametric regression models showed that while age and BMI were significantly associated with systolic BP% in both race groups, black children had significantly higher BP% values as compared with white children of the same age and BMI (Fig 1 (a) and (b)). Although BP% values have taken into account the effect of age, there continued to be a significant effect of age on BP% in black children. In conclusion, among children referred for treatment of obesity, black children are at a significantly greater risk for having elevated BP as compared with their white peers of similar age and severity of obesity. Further research is needed to better understand this population-specific intensification of the adiposity effect on BP in obese black children