Diagnosis of near-fatal pulmonary embolus-in-transit with focused echocardiography.

BACKGROUND: Among patients who die from pulmonary embolus (PE), approximately two-thirds succumb within an hour of presentation. Computed tomography can provide a definitive diagnosis but is associated with practical limitations. Echocardiography can increase diagnostic certainty of PE by visualizing signs of acute right ventricular (RV) strain. This case highlights a potentially lethal finding associated with PE and the role of clinician-performed bedside echocardiography in the timely management of this disease. OBJECTIVE: To describe a case of PE-in-transit diagnosed by clinician-performed focused echocardiography. CASE REPORT: A 78-year-old man with lymphoma presented to the Emergency Department with shortness of breath. His blood pressure was 95/53 mm Hg; his oxygen saturation was 84% on room air. A focused echocardiogram showed a highly mobile elongated mass traversing the right atrium and right ventricle, consistent with a PE-in-transit. Anticoagulation was initiated and Cardiovascular Surgery was consulted for emergent thrombectomy. Minutes after reviewing the ultrasound with the surgeons, the patient was transported to the operating room. Just before surgery, the patient had a cardiac arrest. Exploration of his heart failed to reveal thrombus; however, extensive clot burden was removed from the pulmonary arteries, with subsequent return of spontaneous circulation. CONCLUSION: The clinician performed a focused echocardiogram to evaluate the cause of the patient's critical state. PE-in-transit, a rare entity associated with large PEs, was identified, which obviated the need for further diagnostic evaluation and led to immediate aggressive therapy. Increased familiarity with the uses of bedside sonography in the evaluation of shock and respiratory distress may allow clinicians to become more proficient in managing these patients.

Acyl coenzyme A dependent retinol esterification by acyl coenzyme A: diacylglycerol acyltransferase 1.

We provide biochemical evidence that enzymes involved in the synthesis of triacylglycerol, namely acyl coenzyme A:diacylglycerol acyltransferase (DGAT) and acyl coenzyme A:monoacylglycerol acyltransferase (MGAT), are capable of carrying out the acyl coenzyme A:retinol acyltransferase (ARAT) reaction. Among them, DGAT1 appears to have the highest specific activity. The apparent K(m) values of recombinant DGAT1/ARAT for retinol and palmitoyl coenzyme A were determined to be 25.9+/-2.1 microM and 13.9+/-0.3 microM, respectively, both of which are similar to the values previously determined for ARAT in native tissues. A novel selective DGAT1 inhibitor, XP620, inhibits recombinant DGAT1/ARAT at the retinol recognition site. In the differentiated Caco-2 cell membranes, XP620 inhibits approximately 85% of the Caco-2/ARAT activity indicating that DGAT1/ARAT may be the major source of ARAT activity in these cells. Of the two most abundant fatty acyl retinyl esters present in the intact differentiated Caco-2 cells, XP620 selectively inhibits retinyl-oleate formation without influencing the retinyl-palmitate formation. Using this inhibitor, we estimate that approximately 64% of total retinyl ester formation occurs via DGAT1/ARAT. These studies suggest that DGAT1/ARAT is the major enzyme involved in retinyl ester synthesis in Caco-2 cells.