Intranuclear Hemoglobin in Erythroblasts of beta-Thalassemia

The amount and distribution of intranuclearhemoglobin in erythroblasts of normal subjects and patients with homozygous -thalassemia were studied by microspectrophotometric methods. The mean intranuclear hemoglobin content of the matureerythroblasts represented 33%-40% of thetotal hemoglobin content both in normaland thalassemic cells. Distinct absorptionpeaks in transmission scanning linesrecorded over thalassemic erythroblastssuggested the presence of intranuclear hemoglobin precipitation in some cells.Similar characteristic absorption peaks ofdenatured ferric hemoglobin were recordedover large inclusions of the cytoplasm andsmall intranuclear precipitates. Intranuclearinclusion bodies may be responsible for thedisturbance of erythroblast proliferation inthalassemia, thus explaining in part theineffective erythropoiesis occurring in thisdisease.

Submitted on December 18, 1972 Revised on June 22, 1973 Accepted on July 31, 1973     

Characteristics and longer-term outcomes of paravalvular leak after aortic and mitral valve surgery

Background

Paravalvular leak (PVL) is often seen after aortic (AV) and mitral valve (MV) surgery, either due to infection or valve dehiscence. We sought to describe predictors of longer-term outcomes in patients who developed PVL after AV and MV surgery and were considered eligible for reoperative cardiac surgery (RCS).

Cholic acid mediates negative feedback regulation of bile acid synthesis in mice

Cholesterol is converted into dozens of primary and secondary bile acids through pathways subject to negative feedback regulation mediated by the nuclear receptor farnesoid X receptor (FXR) and other effectors. Disruption of the sterol 12alpha-hydroxylase gene (Cyp8b1) in mice prevents the synthesis of cholate, a primary bile acid, and its metabolites. Feedback regulation of the rate-limiting biosynthetic enzyme cholesterol 7alpha-hydroxylase (CYP7A1) is lost in Cyp8b1(-/-) mice, causing expansion of the bile acid pool and alterations in cholesterol metabolism. Expression of other FXR target genes is unaltered in these mice. Cholate restores CYP7A1 regulation in vivo and in vitro. The results implicate cholate as an important negative regulator of bile acid synthesis and provide preliminary evidence for ligand-specific gene activation by a nuclear receptor.     

Growing experience with extracorporeal membrane oxygenation as a bridge to lung transplantation

Extracorporeal membrane oxygenation (ECMO) is rarely used as a bridge to lung transplantation (BTT) because of its associated morbidity and mortality. However, recent advancements in perfusion technology and critical care have revived interest in this application of ECMO. We retrospectively reviewed our utilization of ECMO as BTT and evaluated our early and midterm results. Nineteen patients were placed on ECMO with the intent to transplant of which 14 (74%) were successfully transplanted. Early and midterm survival of transplanted patients was 75% (1 year) and 63% (3 years), respectively, with the most favorable results observed in interstitial lung disease patients supported in the venovenous configuration. Extracorporeal membrane oxygenation-bridged transplant survival rates were equivalent to nonbridged recipients, but early morbidity and mortality are high and the failure to bridge to transplant is significant. Overall, successfully bridged patients can derive a tangible benefit, albeit with considerable consumption of resources.     

Spontaneous coronary artery dissection in Ehlers-Danlos syndrome

Ehlers-Danlos syndrome is a heterogeneous group of connective tissue disorders with type IV, the vascular subtype, behaving as the most severe largely due to spontaneous arterial aneurysm and dissection. In this case report we describe a spontaneous left anterior descending coronary artery dissection treated with coronary artery bypass graft in a patient with Ehlers-Danlos syndrome type IV.