Umbilical catheter masquerading at echocardiography as a left atrial mass.

The case of a newborn who had an umbilical catheter inserted in the intensive care unit is discussed. This catheter was meant to be inserted into the umbilical artery, but was instead inadvertently inserted into the umbilical vein. It crossed a patent foramen ovale into the left atrium.

The role of lysosomes and microtubules in cardiac protein degradation.

The mechanisms and regulatory factors involved in cardiac proteolysis are incompletely understood. Agents that interfere with lysosomal function (e.g.

Direct anabolic effects of thyroid hormone on isolated mouse heart.

The direct effects of L-and D-triiodothyronine (T3) on cardiac protein metabolism were investigated using fetal mouse hearts in organ culture. This model allowed the production of "thyrotoxicosis" in isolated hearts in vitro in the absence of the usual systemic metabolic and hemodynamic effects of thyroid hormones. Hearts were studied during the first 24 h of T3 exposure in culture, before changes in beating rate due to T3 occurred.

Changes in cardiac cathepsin B activity in response to interventions that alter heart size or protein metabolism: comparison with cathepsin D.

The specific activity of cardiac cathepsin B is significantly decreased by starvation and corticosteroid treatment in vivo, and by exposure of the heart in vitro to insulin, hydrocortisone and cycloheximide. Increases in cathepsin B activity occur following isoproterenol-induced cardiac damage in vivo and exposure in vitro to sucrose. Cathepsin B activity in heart is not changed during normal aging or in thyrotoxicosis.