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Biomedical subjects

Michael A Meyer

Publications and source records attributed to Michael A Meyer.

9 recordsLinked to original sources

The NASA Astrobiology Roadmap.

The NASA Astrobiology Roadmap provides guidance for research and technology development across the NASA enterprises that encompass the space, Earth, and biological sciences. The ongoing development of astrobiology roadmaps embodies the contributions of diverse scientists and technologists from government, universities, and private institutions. The Roadmap addresses three basic questions: How does life begin and evolve, does life exist elsewhere in the universe, and what is the future of life on Earth and beyond? Seven Science Goals outline the following key domains of investigation: understanding the nature and distribution of habitable environments in the universe, exploring for habitable environments and life in our own solar system, understanding the emergence of life, determining how early life on Earth interacted and evolved with its changing environment, understanding the evolutionary mechanisms and environmental limits of life, determining the principles that will shape life in the future, and recognizing signatures of life on other worlds and on early Earth. For each of these goals, Science Objectives outline more specific high-priority efforts for the next 3-5 years. These 18 objectives are being integrated with NASA strategic planning.

Earth, Planet↗

Thrombus-in-transit and paradoxical embolism.

Paradoxical embolism is an uncommon but clinically important phenomenon. Elements of diagnosis include the presence of: (1) a venous thrombus, (2) an arterial embolus, (3) a communication between the right and left heart, and (4) a thrombus traversing such a communication. Unfortunately, all of these elements can be rarely demonstrated in each case but the probability should be considered in any patient with 2 or more present. It should be suspected in patients who have evidence of systemic arterial emboli without apparent cause. A transesophageal echocardiogram with contrast should be considered in cases where paradoxical embolism is a possibility. We present a case in which a "thrombus-in-transit" was imaged across the interatrial septum in a patient with a patent foramen ovale, deep venous thrombosis, and an embolic cerebrovascular stroke.

Aged↗

Flumazenil responsive ornithine transcarbamylase deficiency encephalopathy: clinical and radiographic features.

A 22-year-old woman with a negative urine drug screen and somnolence rapidly reversed by intravenous flumazenil was found to have elevated ammonia levels and punctate calcifications of the subcortical frontal white matter. Abnormally high levels of orotic acid were found in serum and urine, confirming the diagnosis of ornithine transcarbamylase deficiency. Although computed tomography findings are non-specific, young patients with unexplained hyperammonemic states of somnolence reversed by flumazenil should be screened for this X-linked recessive metabolic disorder.

Adult↗