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Biomedical subjects

A Lerman

Publications and source records attributed to A Lerman.

115 records · Page 7Linked to original sources

The effect of hyperbaric oxygen on acute experimental sulfide poisoning in the rat.

In order to evaluate the efficiency of hyperbaric oxygen in experimental acute sulfide poisoning, we studied the effect of 1 ATA (atmosphere absolute) oxygen and sodium nitrite therapy. We then studied the effect of oxygen at 3 ATA alone and in combination with intraperitoneal sodium nitrite injection on rats poisoned by intraperitoneal injection of LD75 sulfide. Electroencephalogram and heart rate were continuously monitored. We also studied the effect of sodium nitrite and hyperbaric oxygen administered before the poisoning (protective effect). In our experimental set, death of untreated poisoned animals occurred within 5 min. There is a parallel between modification of the EEG pattern and apnea. Respiratory arrest always preceded cardiac arrest. Pure oxygen (1 ATA O2) is effective in preventing death in experimental sulfide poisoning. 3 ATA oxygen was significantly more effective in preventing death than 1 ATA oxygen, or sodium nitrite alone. The best therapeutic regimen was a combination of 3 ATA oxygen and sodium nitrite administration.

Animals↗

C-type natriuretic peptide immunoreactivity in human breast vascular endothelial cells.

The present study was undertaken to determine the presence of CNP immunoreactivity in human breast tissue (n = 9). Immunohistochemical staining of breast tissue revealed the presence of CNP immunoreactivity localized to vascular endothelial cells. This study demonstrates for the first time that CNP immunoreactivity is present in humans. Based upon the knows biological actions of CNP, these findings suggest that CNP may function as part of an endothelium-derived vasoregulatory system.

Atrial Natriuretic Factor↗

The endothelium: dysfunction and beyond.

Since its anatomic discovery in the 19th century, the endothelium was considered to fulfill no other purpose than that of a physical barrier between blood and tissue, until Furchgott and colleagues defined endothelium-dependent vasoreactivity in the late 1970s. Henceforth, a functional paradigm defined the balance between endothelium-derived relaxing factors and endothelium-derived contracting factors as the hallmark of endothelial cell integrity. As a consequence, any reflection of a deviation from this state was defined as endothelial dysfunction, most notably the impairment of vasorelaxation in response to pharmacologic stimuli such as acetylcholine or nonpharmacologic stimuli such as shear stress and cold pressor. Within the coronary artery tree these alterations have been recognized before the development of obstructive coronary artery disease, affecting the microcirculation before the epicardial conduit vessel. Furthermore, recent clinical trials outlined the prognostic significance of these changes, whereby impairment of increase in coronary blood flow in response to endothelium-dependent stimuli seemed to be of utmost importance. Thus it is intriguing to speculate on the evolving role of myocardial perfusion imaging in combination with pharmacologic and nonpharmacologic stimuli for the noninvasive assessment of coronary endothelial dysfunction in patients at risk for future adverse events. At a minimum, this review aims to put endothelial dysfunction into an imaging perspective beyond the scope of the conventional approach.

Animals↗

Methylergonovine-induced diffuse coronary spasm in a patient with exercise-induced coronary spasm after heart transplantation.

Coronary artery spasm is a rarely reported condition after heart transplantation. We report a case of exercise-induced coronary artery spasm in a patient 1-year after orthotopic heart transplantation. Serial quantitative coronary angiography showed significant diffuse loss of luminal diameter. Provocative testing with intracoronary acetylcholine and intravenous methylergonovine maleate was performed in an effort to document efficacy of the antispasm regimen. Infusion of acetylcholine into the left anterior descending coronary artery resulted in transient closure of the vessel. Diffuse spasm resulting in hypotension and ventricular fibrillation occurred with intravenous methylergonovine maleate administration. Because of the risk of provoking diffuse spasm, intravenous administration of methylergonovine maleate should be avoided in the posttransplantation setting. Review of the literature suggests that coronary artery spasm after transplantation is often associated with severe transplant coronary artery disease and may be associated with a poor prognosis. Coronary artery spasm may be a more common cause of syncope and death after transplantation than it is currently thought to be.

Acetylcholine↗