Diagnosis of early human myocardial ischemic damage with electron probe microanalysis

We determined the Na/K x-ray intensity ratio in frozen sections of myocardial tissues obtained at autopsy from patients who died from various causes, using electron probe analysis. We have been able to distinguish between the ischemically injured and normal cells. The method is simple, fast, and dependable even when the duration of ischemia is only 30 minutes.     

Barotrauma and air embolism in hyperbaric oxygen therapy

A 69-year-old woman underwent hyperbaric oxygen therapy because of a nonhealing ulcer of her foot. During decompression, she developed a left-sided hemiplegia and confusion. Recompression resulted in transient neurologic improvement, but she eventually became comatose. Ventricular dysrhythmias developed and she died without regaining consciousness 17 h after onset of symptoms. An autopsy revealed diffuse interstitial pulmonary fibrosis with severe paracicatricial emphysema, chronic interstitial inflammation, and chronic bronchitis with abundant intrabronchial mucus. There was extensive multifocal ischemic injury of the cerebral cortex. The hippocampi, basal ganglia, and cerebellum were spared. Scattered acute myofiber necrosis was present in the heart. Clinical presentation and autopsy findings strongly support the diagnosis of air embolism and illustrate a potential risk of hyperbaric oxygen therapy in patients with preexisting pulmonary disease.     

School Vouchers and Student Outcomes: Experimental Evidence from Washington,DC

School vouchers are the most contentious form of parental school choice. Vouchers provide government funds that parents can use to send their children to private schools of their choice. Here we examine the empirical question of whether or not a school voucher program in Washington, DC, affected achievement or the rate of high school graduation for participating students. The District of Columbia Opportunity Scholarship Program (OSP) has operated in the nation's capital since 2004, funded by a federal government appropriation. Because the program was oversubscribed in its early years of operation, and vouchers were awarded by lottery, we were able to use the “gold standard” evaluation method of a randomized experiment to determine what impacts the OSP had on student outcomes. Our analysis revealed compelling evidence that the DC voucher program had a positive impact on high school graduation rates, suggestive evidence that the program increased reading achievement, and no evidence that it affected math achievement. We discuss the implications of these findings in light of recent policy developments including the reauthorization of the OSP and the enactment or expansion of more than a dozen school voucher or voucher‐type programs throughout the United States in 2011 and 2012.