Grade 2 cellular heart rejection: does it exist?

According to the International Society for Heart and Lung Transplantation, a single focus of lymphocytic infiltration associated with myocyte injury in a cardiac allograft endomyocardial biopsy is focal moderate cellular rejection (Grade 2). We reviewed 115 endomyocardial biopsy specimens that were completely negative (n = 17), had a Quilty A (n = 17) or Quilty B (n = 46) lesion, or had a lesion fulfilling the criteria of grade 2 rejection (n = 35). By studying step sections (mean = 18) or sections stained for elastic tissue and collagen, we showed continuity of the focus of grade 2 rejection with the endocardium in 32 of 35 cases; these results justify reclassification of these foci as Quilty B lesions, which are defined as endocardial infiltrates that encroach on the underlying myocardium and that may be associated with myocyte injury but are not generally considered to represent acute rejection.

Pathology of atheromatous lesions in inbred and genetically engineered mice. Genetic determination of arterial calcification.

We report comprehensive pathological studies of atheromatous lesions in various inbred mouse strains fed a high-fat, high-cholesterol diet and in two genetically engineered strains that develop spontaneous lesions on a low-fat chow diet. Coronary and aortic lesions were studied with respect to anatomic locations, lesion severity, calcification, and lipofuscin deposition. Surprisingly, the genetic determinants for coronary fatty lesion formation differed in part from those for aortic lesion development.

Use of therapeutic ultrasound in percutaneous coronary angioplasty. Experimental in vitro studies and initial clinical experience.

Background: Previous studies have shown the feasibility of peripheral arterial ultrasound angioplasty.

Methods And Results: In this report, we describe the use of percutaneous therapeutic ultrasound for coronary angioplasty. In vitro, 11 postmortem, atherosclerotically occluded coronary arteries were obtained to assess catheter-delivered ultrasound for arterial recanalization as well as for assessment of the size of particulate debris.

Catheter-delivered high intensity, low frequency ultrasound induces vasodilation in vivo.

This study investigated the effect of intravascular high intensity, low frequency catheter-delivered ultrasound on vasomotor behaviour in vivo. Catheter-delivered therapeutic ultrasound induces endothelium-independent vasodilation in vitro. To study this effect in vivo we analysed the angiograms of canine coronaries and human femoropopliteal arteries before and after ultrasound exposure.

Involvement of the tyrosinase gene in the deposition of cardiac lipofuscin in mice. Association with aortic fatty streak development.

Lipofuscin pigment, a terminal oxidation product, accumulates within cells during the normal aging process and under certain pathological conditions. We have analyzed a genetic cross between two inbred mouse strains, BALB/cJ and a subline of C57BL/6J, which differ in lipofuscin deposition. A comparison of the segregation pattern of cardiac lipofuscin with the albino locus (c) on mouse chromosome 7 revealed complete concordance.

Sudden death of a carrier of X-linked Emery-Dreifuss muscular dystrophy.

Objective: To report a sudden death in a female carrier of Emery-Dreifuss muscular dystrophy and to describe the cardiac abnormalities associated with this disease.

Study Design: Case series.

Setting: University hospital.

Implantation and recovery of temporary metallic stents in canine coronary arteries.

Objectives: The purpose of this study was to test the feasibility of implanting and retrieving a heat-activated recoverable temporary stent and to determine its effect on the angiographic, gross and histologic appearance of a normal coronary artery wall.

Background: Permanent coronary stenting is associated with a significant incidence of thrombosis, bleeding and vascular complications. These may be avoided by temporarily stenting for a period of hours to several days.

Histopathologic correlation of the three-layered intravascular ultrasound appearance of normal adult human muscular arteries.

The purpose of this study was to correlate intravascular ultrasound images from normal peripheral muscular arteries with the microscopic arterial components by using surgical microdissection techniques. There has been uncertainty about the precise anatomic constituents that are represented by the intravascular ultrasound three-layer image in human peripheral arteries. Forty of 66 grossly normal human femoropopliteal arterial segments obtained at autopsy were found to have a three-layered appearance and were subjected to selective surgical microdissection of intima, media, or adventitia.

Immune-complex-mediated vasculitis increases coronary artery lipid accumulation in autoimmune-prone MRL mice.

MRL/lpr mice develop severe autoimmune disease and vasculitis by 5 months of age, whereas congenic strain MRL/n mice exhibit much milder vasculitis with a later age of onset. When maintained on a high-fat, high-cholesterol (atherogenic) diet, strain MRL/lpr mice exhibited a striking deposition of lipid in both the large and small coronary arteries, whereas strain MRL/n mice exhibited very little lipid accumulation. Neither strain exhibited lipid accumulation on a low-fat chow diet.

Distribution of circumferential stress in ruptured and stable atherosclerotic lesions. A structural analysis with histopathological correlation.

Background: Although rupture of an atherosclerotic plaque is considered to be the cause of most acute coronary syndromes, the mechanism of plaque rupture is controversial.

Methods And Results: To test the hypothesis that plaque rupture occurs at sites of high circumferential stress in the diseased vessel, the distribution of stress was analyzed in 24 coronary artery lesions. Histological specimens from 12 coronary artery lesions that caused lethal myocardial infarction were compared with those from 12 stable control lesions.

Effect of varying laser parameters on pulsed Ho:YAG ablation of bovine knee joint tissues.

We investigated the effect of varying laser parameters on ablation of fresh bovine knee joint tissues (fibrocartilage, hyaline cartilage, and bone) with a free-running Ho:YAG laser. Ablation rate was measured in saline for each tissue type as a function of laser fluence (160-950 J/cm2), pulse width (150-450 microseconds, full width at half maximum), and fiber core diameter (400 and 600 microns). A weight that was attached to the fiber end was used to exert a constant pressure of 40 g/mm2 to the tissue underneath to ensure a constant contact between the fiber tip and the tissue throughout the ablation process.

Use of laser energy to treat central pulmonary emboli: a preliminary report.

We evaluated the ability and safety of a laser fiber placed percutaneously into a pig's lobar pulmonary artery to lyse pulmonary artery blood clots that were created in situ. We developed a model to create blood clots in situ that could be placed in any desired location with a radio-opaque marker at the clot position. An excimer laser delivered energy to a flexible 600 microns fiber in three experiments and a coaxial 1.

Cytokine expression and endothelial cell and lymphocyte activation in human cardiac allograft rejection: an immunohistochemical study of endomyocardial biopsy samples.

We used monoclonal antibodies and immunohistochemical staining of frozen tissue sections to study the expression of cytokines in human cardiac allograft rejection. The 113 endomyocardial biopsy samples were stained for interleukin (IL)-2, IL-6, and interferon-gamma. The findings were compared to expression of the endothelial cell adhesion molecule ICAM-1, and the lymphocyte receptor for the adhesion molecule VCAM-1, VLA-4.

In vitro validation of three-dimensional intravascular ultrasound for the evaluation of arterial injury after balloon angioplasty.

Objectives: The hypothesis of this study was that three-dimensional ultrasound imaging would facilitate the evaluation of arterial dissection after balloon angioplasty.

Background: The presence and extent of arterial dissection occurring at the time of balloon angioplasty may be important predictors of abrupt vessel closure or late restenosis.

Methods: Forty-one human arterial segments obtained after death were imaged in an in vitro system at physiologic pressure (80 to 100 mm Hg) before and after balloon angioplasty.

Expression of cell adhesion molecules in human cardiac allograft rejection.

Adhesion of leukocytes to vascular endothelial cells is a critical step in a variety of inflammatory conditions. We studied the expression and distribution of intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1) in frozen sections of 83 endomyocardial biopsy specimens from human allograft hearts using monoclonal antibodies and an avidin-biotin complex-alkaline phosphatase staining technique. Cases with cellular or humoral rejection and Quilty lesions were studied.

Proliferating cell nuclear antigen immunohistochemistry in rat aorta after balloon denudation. Comparison with thymidine and bromodeoxyuridine labeling.

The authors compared detection of proliferating vascular smooth muscle cells (SMC) in vitro and in vivo with proliferating cell nuclear antigen (PCNA) immunohistochemistry and two established methods: [3H]thymidine autoradiography and bromodeoxyuridine immunohistochemistry. Labeling with [3H]thymidine and bromodeoxyuridine of rat vascular SMC in culture stained 11% +/- 2% and 11% +/- 1% of cells, and PCNA immunohistochemistry 22% +/- 2% of cells. Proliferation in the media of the denuded rat aortae was highest 3 days after denudation: 4.

Bradyarrhythmias requiring pacemaker implantation after orthotopic heart transplantation: association with rejection.

Patients with severe sinus-node dysfunction that required pacemaker implantation after orthotopic heart transplantation were reviewed. During a 21-month period, 42 transplantations were performed in 41 patients. Five patients (12.

Effects of hypophysectomy on vascular insulin-like growth factor-I gene expression after balloon denudation in rats.

Insulin-like growth factor-I (IGF-I) is a widely distributed mediator of the growth promoting effects of growth hormone (GH). We sought to determine whether the relationship between GH and IGF-I extends to the vascular system, where IGF-I is proposed to participate in the process of neointimal proliferation after balloon denudation. We show that in hypophysectomized rats basal aortic IGF-I mRNA is one-tenth that of normal rats and is increased after balloon denudation.

The severity of atherosclerosis at sites of plaque rupture with occlusive thrombosis in saphenous vein coronary artery bypass grafts.

Atherosclerotic plaque rupture with superimposed thrombosis is recognized as the lesion causing late, acute, thrombotic saphenous vein coronary artery bypass graft (CABG) occlusion. To determine the severity of atherosclerosis at the site of plaque rupture, 68 saphenous vein CABGs removed at the time of reoperation or at autopsy were studied. The study population consisted of 57 men, 64 +/- 9 years old, and nine women, 70 +/- 10 years old.

Dissolution of peripheral arterial thrombi by ultrasound.

Background: We have previously shown that continuous-wave ultrasound can rapidly dissolve human thrombi in vitro, with 99% of all residual particles measuring less than 10 microns in diameter. To assess the effects of pulsed-wave ultrasound energy on whole blood clots, 1) in vitro studies were preformed to assess precisely the rates of clot disruption and to quantify particulate size, and 2) in vivo studies were performed to assess the efficacy and safety of catheter-delivered ultrasound for intra-arterial thrombus dissolution.

Methods And Results: In vitro, we studied 50 samples of human whole blood clots and using an 89-cm-long wire probe, applied pulse-wave energies from 8 to 23 W.

Differences in infarct size with lidocaine as compared with bretylium tosylate in acute myocardial ischemia and reperfusion in pigs.

The effects of the antiarrhythmic drugs lidocaine and bretylium tosylate on myocardial necrosis were studied in anesthetized pigs subjected to 60-min coronary occlusion followed by 3-h reperfusion. Group A (n = 7) received lidocaine (average dose +/- SD = 1,828 +/- 515 mg) before and during coronary occlusion and after reperfusion; the other series (group B, n = 7) received bretylium tosylate (3,457 +/- 1,323 mg). Infarct size was 16.

Cardiac manifestations of acquired immune deficiency syndrome: a 1991 update.

Cardiac involvement is being identified more often clinically and at autopsy in patients with AIDS. Recent estimates suggest that in the United States as many as 5000 patients per year may have cardiac complications resulting from HIV infection. Patients with AIDS may have pericardial, myocardial, and/or endocardial disease.

Histopathologic validation of angioscopy and intravascular ultrasound.

Background: To establish a histopathologic basis for angioscopic and ultrasound image interpretation we studied 70 postmortem human arterial segments in vitro.

Methods And Results: We used 7- to 9-French fiber-optic angioscopes and 20- to 30-MHz intravascular ultrasound imaging catheters. Three observers assigned an angioscopic and ultrasound image classification to each vessel segment.