Ocean acidification alters properties of the exoskeleton in adult Tanner crabs, Chionoecetes bairdi.

Ocean acidification can affect the ability of calcifying organisms to build and maintain mineralized tissue. In decapod crustaceans, the exoskeleton is a multilayered structure composed of chitin, protein and mineral, predominately magnesian calcite or amorphous calcium carbonate (ACC). We investigated the effects of acidification on the exoskeleton of mature (post-terminal-molt) female southern Tanner crabs, Chionoecetes bairdi Crabs were exposed to one of three pH levels - 8.1, 7.8 or 7.5 - for 2 years. Reduced pH led to a suite of body region-specific effects on the exoskeleton. Microhardness of the claw was 38% lower in crabs at pH 7.5 compared with those at pH 8.1, but carapace microhardness was unaffected by pH. In contrast, reduced pH altered elemental content in the carapace (reduced calcium, increased magnesium), but not the claw. Diminished structural integrity and thinning of the exoskeleton were observed at reduced pH in both body regions; internal erosion of the carapace was present in most crabs at pH 7.5, and the claws of these crabs showed substantial external erosion, with tooth-like denticles nearly or completely worn away. Using infrared spectroscopy, we observed a shift in the phase of calcium carbonate present in the carapace of pH 7.5 crabs: a mix of ACC and calcite was found in the carapace of crabs at pH 8.1, whereas the bulk of calcium carbonate had transformed to calcite in pH 7.5 crabs. With limited capacity for repair, the exoskeleton of long-lived crabs that undergo a terminal molt, such as C. bairdi, may be especially susceptible to ocean acidification.

Hypertensive emergencies in diabetic patients from predominantly African American urban communities.

Aim: The aim of this study was to identify risk factors for hypertensive emergencies in diabetic patients presenting with severely elevated blood pressure. Methods: Using electronic medical records, this study identified diabetic patients with hypertensive crisis who presented to the emergency department of Newark Beth Israel Medical Center, Newark, NJ from June 2013 to May 2016. Diabetic patients with hypertensive emergencies were compared with non-diabetic patients based on important demographic and clinical characteristics. Results: Patients with diabetes accounted for 52.27% of all hypertensive emergencies during the study period. There were 264 diabetic patients with hypertensive emergencies and 519 diabetic patients with hypertensive urgencies. The majority of patients were African Americans (88.6%). The odds of hypertensive emergencies were strikingly higher in diabetic patients with hyperlipidemia (OR 1.66, 95% CI 1.23-2.24), coronary artery disease (OR 2.95, 95% CI 2.15-4.05), congestive heart failure (OR 6.28, 95% CI 4.49-8.80), renal insufficiency (OR 2.84, 95% CI 2.10-3.86) and low hemoglobin (OR 0.9, 95% CI 0.84-0.97). Acute or worsening heart failure was the most frequent acute target organ injury (49.6%) followed by non-ST elevation myocardial infarction (41.7%). Diabetic and non-diabetic patients had similar rates of target organ injuries. Conclusion: The development of hypertensive emergencies in patients with diabetes was not because of diabetes per se but because of coexisting highly elevated blood pressure. Tight blood pressure control may decrease the risk of hypertensive emergencies in this patient population.