Case Report: Androgenetic/biparental chimera with two biparental cell lines leading to placental mesenchymal dysplasia: a possible novel mechanism of formation.

Placental mesenchymal dysplasia (PMD) is a rare placental pathology that may be associated with Beckwith-Wiedemann features in the fetus and may be due to the presence of an androgenetic cell line. Many of the reported PMD cases describe the presence of a biparental and an isodisomic androgenetic cell line. The proposed mechanism of formation is by fertilization of a haploid ovum by a haploid sperm and duplication of the male pronucleus.

Intracoronary infusion of Gd3+ into ischemic region does not suppress phase Ib ventricular arrhythmias after coronary occlusion in swine.

Increased mechanical tension in the ischemic region during acute coronary occlusion might favor the occurrence of phase Ib ventricular arrhythmias. We aimed to investigate whether intracoronary administration of Gd(3+), a stretch-activated channel blocker, into the ischemic zone reduces the incidence of these arrhythmias. In thiopental-anesthetized, open-chest pigs, the left anterior descending coronary artery (LAD) was ligated for 45 or 48 min.

Ventricular fibrillation during acute coronary occlusion is related to the dilation of the ischemic region.

Myocardial stretch induces several electrophysiological changes and arrhythmias, but little is known on its possible role in triggering ventricular fibrillation (VF) during acute coronary occlusion. In thiopental-anesthetized, open-chest pigs submitted to a 40-min ligation of the left anterior descending coronary artery, the association between the early increase in end-diastolic length (measured by means of ultrasonic crystals) in the ischemic region and subsequent VF was analyzed. Animals received no treatment (n = 35) or intravenous nitroglycerin (2.