Protective effects of propionyl-L-carnitine during ischemia and reperfusion

When cardiac function in isolated rat hearts was impaired by subjecting them to ischemia, subsequent perfusion with propionyl-L-carnitine and related compounds increased their rate of recovery. Thus at 11 mM, both propionyl-L-carnitine and, to a lesser extent, its taurine amide, and also acetyl-L-carnitine, significantly restored cardiac function in 15 minutes after 90 minutes of either low-flow or intermittent no-flow ischemia. Carnitine itself was ineffective. Propionyl-L-carnitine also increased tissue ATP and creatine phosphate compared with controls, but did not affect the levels of long-chain acyl carnitine and coenzyme. These esters also depleted fatty acid peroxidation, as shown with malonaldehyde, and were more effective than carnitine in preventing the production of superoxide. In myocytes, propionyl-L-carnitine alone stimulated palmitate oxidation, but in rat heart homogenates, both L-carnitine and propionyl-L-carnitine did so, while acetyl-L-carnitine was actually inhibitory. Possible mechanisms for the protective action of propionyl-L-carnitine against ischemia include an increased rate of cellular transport, stimulation of fatty acid oxidation, and a reduction of free radical formation.

Primary left ventricular hemangiosarcoma diagnosed by endomyocardial biopsy in a dog

An 8-year-old spayed Golden Retriever was examined because of recent onset of congestive heart failure complicated by ventricular arrhythmias. Echocardiography revealed a thickened, hypokinetic region of the left ventricular free wall. Fluoroscopically guided transarterial endomyocardial biopsy of the hypokinetic region of the left ventricle revealed infiltration of the endocradium by neoplastic cells consistent with hemangiosarcoma. The dog's clinical condition deteriorated 7 weeks later, and necropsy confirmed the diagnosis and primary site of origin of the tumor. This report describes the clinical use of an endomyocardial biopsy technique to diagnose an infiltrating myocardial tumor that was associated with signs mimicking canine dilated cardiomyopathy.

Polymorphonuclear leucocytes as potential source of free radicals in the ischaemic-reperfused myocardium

The feasibility of polymorphonuclear leucocytes as a potential source of free radicals during reperfusion of ischaemic myocardium was evaluated. Isolated rat heart was perfused in the presence of f-Met-Leu-Phe-activated and normal polymorphonuclear leucocytes for 30 min. To judge the degree of cellular injury which might result from activated polymorphonuclear leucocytes during perfusion, isolated hearts were also perfused with superoxide anions, hydroxyl radicals, and hypochlorous acid-generating systems in the absence or presence of their corresponding scavengers, superoxide dismutase plus catalase, dimethylthiourea, and allopurinol, respectively. Activated polymorphonuclear leucocytes stimulated the release of lactate dehydrogenase, a biological marker of cellular injury, and malondialdehyde, a presumptive marker for lipid peroxidation; increased tissue injury, as evidenced by morphologic examinations using light and electron microscopy; decreased dry/wet ratios of heart, signifying oedema formation; and reduced myocardial adenosine triphosphate and creatine phosphate content as well as coronary flow, indicating decreased myocardial performance. These biological, physiological, and morphologic parameters were reversed significantly, but not completely, by treating the heart with scavengers, superoxide dismutase plus catalase or allopurinol, but were reversed completely by simultaneous treatment with superoxide dismutase, catalase, and allopurinol. Comparable results were obtained when the hearts were treated with each of these free radical-generating systems and their corresponding scavengers. Generation of free radicals was confirmed either by cytochrome c reduction or by examining the chemiluminescence response using a luminometer. These results indicate that activated polymorphonuclear leucocytes can cause myocardial cellular injury equivalent to the damage caused by free radicals and oxidants which are present in an ischaemic-reperfused heart, suggesting that polymorphonuclear leucocytes may be a potential source of free radicals in the reperfused heart.

Metabolism of indium chelates attached to monoclonal antibody: minimal transchelation of indium from benzyl-EDTA chelate in vivo

The metabolism of radiolabeled antibodies is important for radioimmunoimaging and therapy. The loss of indium-111 (111In) from the chelate can pose problems in imaging and increases the radiation dose to normal tissues. We have evaluated the loss in vivo of 111In from Lym-1-benzyl-EDTA-111In (an antibody conjugated with isothiocyanato-benzyl-EDTA) in normal mice. A monoclonal antibody (CHA 255) that binds to benzyl-EDTA-indium chelates, but not to other forms of indium, was used to measure the percent of 111In remaining in the chelate. Four days after injection, 97.4 +/- 2.2% of the 111In in the liver was still in the benzyl-EDTA chelate, as was 99.4 +/- 0.7% of the 111In in the urine, and 99.1 +/- 0.7% of the 111In in the blood. Studies in vitro indicate that a benzyl-EDTA-111In-antibody-chelate conjugate is more stable in human serum than a benzyl-DTPA-111In conjugate, and that both benzyl-chelate conjugates are much more stable than an unsubstituted DTPA conjugate.

Mesothelioma of the atrioventricular node and congenital complete heart block

Congenital complete heart block (CCHB) has heterogeneous etiologies. It may occur as an isolated entity with no associated congenital cardiac malformations and is difficult to diagnose even with modern technology. Mesothelioma of the atrioventricular (AV) node is a benign tumor that causes CCHB. The occurrence of this tumor is rare, and a definitive diagnosis of the entity is made only at autopsy. The conduction disturbance caused by the mesothelioma is potentially treatable and should be considered in the differential diagnosis of CCHB. We present a case report of a 38-year-old female with CCHB caused by such a tumor. Clinical diagnosis and treatment of CCHB are reviewed.

Surgical pathology of the mitral valve: a study of 712 cases spanning 21 years

The gross surgical pathologic features of the mitral valve were reviewed in 712 patients who had undergone mitral valve replacement at our institution during 1965, 1970, 1975, 1980, and 1985. Among the 452 cases of mitral stenosis, either with or without mitral insufficiency, 99% were attributable to postinflammatory disease and 1% were related to congenital mitral stenosis. Among the 260 cases of pure mitral regurgitation, the two most common causes were a floppy valve (38%) and postinflammatory disease (31%). Moreover, a floppy valve was observed in 73% of the 59 examples of chordal rupture and in 38% of the 16 cases of infective endocarditis. Women accounted for 73% of the 452 cases of mitral stenosis and for 72% of the 530 cases of postinflammatory disease. In contrast, men accounted for 58% of the 260 cases of pure mitral regurgitation, including 76% of the floppy valves and 69% of the infected valves. During the 21 years spanned by the study, the relative frequency of postinflammatory mitral insufficiency progressively decreased, whereas that of floppy mitral valves increased. It is unclear whether aging, heredity, environmental factors, changes in the frequency of acute rheumatic fever, or changes in patient referral practices may account for this observation.

Acute cardiac events temporally related to cocaine abuse

The increasingly widespread use of cocaine in the United States has been accompanied and perhaps exacerbated by the misconception that the drug is not associated with serious medical complications. In particular, the potential for cocaine to precipitate life-threatening cardiac events needs to be reemphasized. We report the clinical and pathological findings in seven people in whom nonintravenous "recreational" use of cocaine was temporally related to acute myocardial infarction, ventricular tachycardia and fibrillation, myocarditis, sudden death, or a combination of these events. We also review data on 19 previously reported cases of cocaine-related cardiovascular disorders. Analysis of all 26 patients indicated the following findings: the cardiac consequences of cocaine abuse are not unique to parenteral use of the drug, since nearly all the patients took the drug intranasally; underlying heart disease is not a prerequisite for cocaine-related cardiac disorders; seizure activity, a well-documented noncardiac complication of cocaine abuse, is neither a prerequisite for, nor an accompanying feature of, cardiac toxicity of cocaine; and the cardiac consequences of cocaine are not limited to massive doses of the drug. Although the pathogenesis of cardiac toxicity of cocaine remains incompletely defined, available circumstantial evidence suggests that cocaine has medical consequences that are equal in importance to its well-documented psychosocial consequences.

Dilated cardiomyopathy: emerging role of endomyocardial biopsy

The development of safe techniques of endomyocardial biopsy has led to a significant increase in our understanding of the etiology and pathogenesis of dilated cardiomyopathy. The scope of patients for whom this technique is absolutely clinically indicated, however, remains quite narrow and should be restricted to those centers with active cardiac transplant programs, large oncology practices, or those involved with active research into the etiology and treatment of patients with heart muscle disease. The most exciting concept to emerge from the use of EMB is the role of myocarditis in the development of dilated cardiomyopathy. It can accurately be stated that a subset of patients with the clinical presentation of dilated cardiomyopathy may in fact have histologic evidence of myocarditis. Although there is a suspicion that immunosuppressive therapy may be helpful, a randomized trial of large numbers of patients is necessary before definitive conclusions may be drawn. If immunosuppressive therapy proves to be efficacious in active myocarditis, then one could argue that all patients with heart failure of unknown cause with no evidence of valvular or coronary artery disease should undergo endomyocardial biopsy as part of the routine diagnostic workup. However, this recommendation must be considered premature. Since routine histologic findings are nonspecific in dilated cardiomyopathy, biochemical, pharmacologic, and cell culture techniques may provide more definitive information regarding the functional state of the heart muscle. In conclusion, endomyocardial biopsy is rapidly emerging as a useful diagnostic tool in the evaluation of patients with heart failure of unknown cause.

Peripartum cardiomyopathy: clinical, hemodynamic, histologic and prognostic characteristics

Peripartum cardiomyopathy is defined as left ventricular dilation and failure, first developing during the third trimester of pregnancy or in the first 6 months postpartum. In an effort to characterize this syndrome in a middle class population, 14 consecutive patients with peripartum cardiomyopathy underwent a detailed history and physical examination, right heart catheterization, M-mode and two-dimensional echocardiography, radionuclide ventriculography and right ventricular endomyocardial biopsy. These patients were then observed with sequential noninvasive studies to determine prognostic indicators. Eight (57%) of these 14 patients were primiparous and an equal number first presented with heart failure concomitant with or immediately before the onset of labor. When these women were compared with 55 patients with idiopathic dilated cardiomyopathy, only mean age at onset of symptoms (28.7 +/- 5.7 versus 48.2 +/- 13.6 years, p less than 0.001) and symptom duration (4.1 +/- 7.7 versus 19.0 +/- 18.4 months, p less than 0.001) differed between the groups. There was no difference in ventricular arrhythmia, left ventricular chamber size, ejection fraction or hemodynamics. Myocyte histologic findings were similar; however, myocarditis was identified in 29% of patients with peripartum cardiomyopathy and in only 9% of those with idiopathic dilated cardiomyopathy. In all patients with peripartum cardiomyopathy and myocarditis, the myocardial biopsy was performed within 1 week of onset of symptoms. Seven (50%) of the patients with peripartum cardiomyopathy had dramatic improvement within 6 weeks of follow-up, and 6 (43%) died.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of intrapericardial tumor in an infant by two-dimensional echocardiography

Two-dimensional echocardiography is a useful noninvasive tool for diagnosing intrapericardial tumors as a cause of respiratory distress or abnormal cardiomediastinal shadow on chest x-ray. Early recognition of these tumors within the pericardium is important since surgical removal is often curative. Cardiac cineangiography is unnecessary to delineate further the tumor and should be reserved for those in which associated intracardiac defects are suspected.

Postoperative evaluation of endomyocardial fibrosis

25 patients with angiographic features suggestive of endomyocardial fibrosis underwent endocardiectomy and atrioventricular valve replacement. There were 8 deaths. 17 survivors were reevaluated after a mean follow-up of 13.5 months. 8 had right ventricular endomyocardial fibrosis (RVEMF) 5 had left ventricular endomyocardial fibrosis (LVEMF) and 4 had biventricular disease (BVEMF). The survivors showed a significant improvement in their clinical features and functional status. There was a significant reduction in atrial size in X-ray. Hemodynamic data showed a significant fall in right heart filling pressure, right ventricular systolic pressure and pulmonary artery mean pressure, and a significant fall in left heart filling pressure in patients with left ventricular disease either alone or as a part of biventricular disease. In ventriculogram, while there was no change in right ventricular shape after endocardiectomy, left ventricular shape was restored to near normal. The significant improvement is mostly due to the correction of the regurgitant lesion and to some extent due to restoration of ventricular compliance.

Photo-induced nicking of deoxyribonucleic acid by ruthenium(II)-bleomycin in the presence of air

A new metallobleomycin, ruthenium(II)-bleomycin A2 was prepared. When irradiated at 366 nm the ruthenium complex (1-10 microM) was found to break a 121-base pair DNA restriction fragment at specific sites (usually the pyrimidine residues located at the 3'-side of guanine). Care was taken to rule out complications due to the presence of trace amounts of iron. Photo-induced damage by cobalt-bleomycin in the presence of light, and redox-mediated damage by bleomycin and iron produced DNA cleavage at sites similar to ruthenium-bleomycin. In contrast to cobalt-bleomycin, ruthenium-bleomycin required oxygen as well as light to cause significant damage to DNA.

Surgical pathology of combined aortic stenosis and insufficiency: a study of 213 cases

The gross surgical pathologic features of the aortic valve were reviewed in 213 patients who had had clinically combined aortic stenosis and insufficiency and aortic valve replacement at our institution during the years 1965, 1970, 1975, and 1980. The three most common causes were postinflammatory disease (69%) and calcification of congenitally bicuspid (19%) and unicommissural (6%) aortic valves. Other causes included infective endocarditis (2%) and congenitally quadricuspid or malformed tricuspid aortic valves (1% each); the cause was indeterminate in 1%. In the postinflammatory and bicuspid states, calcification tended to be more extensive in men than in women. The relative incidence of postinflammatory disease in our study did not change appreciably from 1965 to 1980, despite the steadily decreasing incidence of acute rheumatic fever reported in western countries.