Widely disseminated Pneumocystis carinii infection associated with cytomegalovirus pneumonitis.

We have described the case of a 46-year-old man with disseminated Pneumocystis carinii infection associated with cytomegalovirus pneumonitis. Because CMV causes endothelial damage in the lungs, we suggest that CMV pneumonitis is a risk factor for dissemination of P carinii infection beyond the lungs.

Peripartum cardiomyopathy: the value of endomyocardial biopsy in diagnosis, prognostication, and therapy.

We describe the case of a 21-year-old black female who was readmitted postpartum because of increasing exertional dyspnea, orthopnea, pleuritic chest pain, and pedal edema. The patient underwent a successful course of clinical treatment for peripartum cardiomyopathy consisting of a regimen of digoxin, diuretics, captopril, and heparin. The results of an endomyocardial biopsy done at readmission were normal: there was no evidence of inflammation, necrosis, or fibrosis; the endocardium, intramural arterioles, mitochondria, and ultrastructure were normal, as was the amount of glycogen; nuclear chromatin were evenly dispersed; and no antibodies were found. Previous studies have shown that approximately half of patients who suffer from peripartum cardiomyopathy recover, while half develop a more severe form of dilated cardiomyopathy. We venture to speculate that normal endomyocardial biopsy findings during the acute stage of the disease may be predictive of recovery. With more certainty, we propose that histologic findings from material taken during an acute episode can and should guide the course of therapy.

Familial lethal cardiomyopathy with mental retardation and scapuloperoneal muscular dystrophy.

A family is described with a neuromuscular disorder characterised by possible X-linked recessive inheritance, a benign, slowly progressive muscular dystrophy with predominant humeroperoneal distribution and lack of contractures or pseudohypertrophy, central nervous system involvement, myopia and lethal cardiomyopathy. The possibility of cardiac transplant as life-saving therapy is suggested.

Captopril-induced hyperreninemia in cholesterol-fed rabbits.

The aims of this study were to investigate the potential effects of captopril (CPT)-induced chronic hyperreninemia on atherogenesis, and to describe and quantitate the morphological changes which occur in the juxtaglomerular (JG) apparatus of drug-treated rabbits. Four groups of normotensive New Zealand rabbits were used. Drug control groups were fed regular rabbit chow (Group I), or regular chow supplemented with cholesterol (Group III). Group II animals were fed regular chow and treated with captopril, and Group IV animals were fed the cholesterol-diet and treated with captopril. Daily captopril administration for a period of six months resulted in significantly (p less than 0.001) increased levels of plasma renin activity and blood urea nitrogen. Mean systemic arterial pressure, plasma aldosterone levels, and hematocrits were significantly reduced in the CPT-treated animals as compared to untreated control groups. No effect on atherogenesis was found. Morphometric analysis showed no difference in the size of the glomeruli between the untreated and the CPT-treated, normal-diet groups, however, significant (p less than 0.001) hypertrophy and hyperplasia of the JG complex were observed in all CPT-treated animals. It is concluded that captopril-induced reductions in systemic arterial blood pressure and perfusion pressure, in concert with a blocked renin-angiotensin system which interferes with the normal autoregulation of renal blood flow and glomerular filtration, leads to significant morphologic and functional alterations in the kidney of normotensive animals.

X-ray microanalysis of calcium in ischemic myocardium: a new method of rapid freezing.

X-ray microanalysis of biological material is best accomplished on unfixed frozen tissue sectioned on a cryoultramicrotome. The need for ultra-rapid freezing to minimize ice crystal artifact has been well documented but is difficult to achieve without the use of potentially hazardous Isopentane or Freon 22 in liquid nitrogen slush. In the present study we employ a slurry of powdered graphite in liquid nitrogen to obtain rapid freezing of cardiac tissue. The results obtained were as good as those which are achieved with Freon 22 in liquid nitrogen, and subsequent cryoultramicrotomy produced thin sections relatively free of ice crystal artifact. Microanalysis revealed a slight increase in mitochondrial calcium as compared with cytoplasmic calcium in normal myocytes. Mitochondrial calcium concentration rose significantly after 30 min of ischemia while only a slight rise in cytoplasmic calcium occurred. These findings suggest that the techniques employed are adequate for detecting ion shifts which occur during ischemia and may be useful for determining the effects of therapeutic agents at the organellar level.

Pulmonary asbestos body counts and electron probe analysis of asbestos body cores in patients with mesothelioma: a study of 25 cases.

Malignant mesotheliomas of the pleura and peritoneum are well-recognized risks of asbestos exposure. We determined the asbestos body content of the lungs from 24 cases of malignant mesothelioma (19 pleural, five peritoneal) and compared such to the content of lungs from 50 consecutive adult autopsies and four cases of overt asbestosis using a Clorox-digestion concentration technique. The cores of 90 asbestos bodies were examined by energy dispersive x-ray analysis and compared with similar data from 120 standard asbestos fibers and 20 fiberglass fibers. The malignant mesothelioma patients had asbestos body counts intermediate between those of the general population and those of patients with asbestosis, although some of the mesothelioma cases overlapped with the general population. These latter cases often lacked an identifiable occupational exposure to asbestos. EDXA studies demonstrated an amphibole core in 88 of the 90 asbestos bodies (amosite or crocidolite in 80 of 88, anthophyllite or tremolite in eight of 88), and chrysotile in two instances.

Capoten-induced juxtaglomerular hyperplasia in rabbits.

The effects of the converting enzyme (CE) inhibitor, captopril, on blood pressure, plasma aldosterone, plasma renin activity (PRA), and kidney morphology were studied. Captopril, at a near maximum daily recommended human dose of approximately 5.0 mg/kg, was administered to rabbits over a period of six months. Mean arterial pressure, CE activity, and aldosterone levels were significantly reduced; PRA and renal renin activity were increased. Microscopic examination of the kidney showed marked hyperplasia of the juxtaglomerular apparatus in all of the treated animals.

Performance of tissue cultured endothelial cells in a mock circulatory loop.

Tissue cultured bovine aortic endothelial cells were subjected to flow in an in vitro circulatory loop which was designed to simulate the flow and pressure conditions in the aorta. The cells were cultured to confluence under stationary conditions on a tube consisting of microfabric backed with polyurethane. The tube with the cultured cells was then added to the flow loop which circulated complete tissue culture medium in a pulsatile mode. Light microscopy, and scanning and transmission electron microscopy showed that the cells not only remained adherent for 2 week periods under flow conditions, but also underwent hypertrophy and proliferation in response to the flow regimen.

Renin as a risk factor for atherogenesis. Part 2. Effects of hypercholesterolemia and hyporeninemia in the rabbit.

Four groups of New Zealand rabbits were used to study the effect of suppressed plasma renin activity (PRA) on atherogenesis. Control groups were fed normal rabbit chow (Group I) or normal chow supplemented with 0.25% cholesterol--0.75% corn oil (Group III). Group II animals were fed normal chow and received periodic injections of 11-desoxycorticosterone (DOC)pivalate and 0.5% saline to drink, while Group IV animals were treated similarly except that they were also fed the atherogenic diet. Blood pressure and blood chemistry measurements were performed monthly over a 7-month period. The blood pressure was unaffected by either the diet or the DOC-saline treatment, however, the PRA was greatly reduced in the animals receiving DOC-saline (Groups II and IV). Similarly, plasma aldosterone was significantly (P less than 0.05) reduced in the DOC-saline-treated animals. No atheromata were observed in the animals consuming the regular diet, regardless of DOC-saline treatment. All of the animals fed the atherogenic diet showed extensive aortic atheromata. However, there was no difference in the lesion index between the animals with normal PRA levels (Group III) and those with suppressed PRA levels (Group IV). Likewise, microscopic evaluation of the aorta, coronary arteries, and renal arteries failed to show a consistent difference in the vascular involvement between animals of Groups III and IV. We therefore conclude that the suppression of PRA does not have a protective effect on atherogenesis in the cholesterol-fed normotensive rabbit.

Human smooth muscle cells cultured from atherosclerotic plaques and uninvolved vessel wall.

Smooth muscle cells (SMC) were cultured from atherosclerotic plaques and uninvolved arteries to determine if differences exist between growth characteristics or ultrastructure of the cultured cells. Eighteen aortic punch biopsies provided the uninvolved tissue, and 58 carotid plaques provided the atherosclerotic tissue. Eighty percent of the samples yielded viable cultured cells, which reached a maximum population doubling time during log phase growth of 72 h (seeding density = 1.0 x 10(4) cells/cm2, 2nd passage). Growth characteristics of both normal and plaque-derived cells were the same in vitro. Growth rate declined with time in culture, and cell division ceased by the 5th or 6th passage. In culture, spindle shaped cells formed the "hill and valley" configuration typical of SMC. Plaque-derived SMC were ultrastructurally similar to SMC from uninvolved vessel wall. Proliferative potential did not vary with age or sex, with method of culture, or with whether the cells were plaque derived or not.

Enzyme release and morphological changes in leukocytes induced by mechanical trauma.

Polymorphonuclear (PMN) leukocytes exposed to mechanical trauma in vitro will release enzymes both from azurophilic and specific granules at shear stress levels of between 75 and 150 dyn/cm2 for 10 min. In addition, at these shear stresses the leukocyte count in whole blood decreased only slightly and the number of ruptured leukocytes on Wright-stained blood films increased significantly. At higher shear stresses, enzyme release and leukocyte damage increased monotonically. Transmission electron microscopy evaluation of sheared PMNs revealed that remaining intact cells had minor morphological changes at stresses of 150 dyn/cm2. They were characterized by clublike cytoplasmic potrusions, spherical shape, and a circumferential distribution of cytoplasmic granules. At higher shear stresses (600 dyn/cm2) cell destruction was marked. Intact PMNs contained fewer cytoplasmic granules, a large number of vacuoles, and condensed nuclear chromatin. These studies show that PMN morphology and function are at least as sensitive to mechanical trauma as similar platelet alterations seen in other studies.

Comparison of tissue-cultured bovine endothelial cells from aorta and saphenous vein.

Endothelial cells were harvested from bovine aorta and saphenous vein with collagenase and cultured in McCoy's 5a medium (modified GIBCO) supplemented with 10% fetal bovine serum. The cells were subcultured through 17 passages over 4 to 5 months. The growth properties in culture of the two cell types were compared. Morphological comparisons included phase microscopy and scanning and transmission electron microscopy. Comparisons with cultured aortic smooth-muscle cells were made using phase and scanning electron microscopy. No differences were found between cultured endothelial cells from aorta and saphenous vein. Differences in growth patterns in culture clearly distinguished both endothelial cell types from smooth-muscle cells. The presence of Weibel-Palade bodies identified the cells from both sources as endothelial.

Control of 3-hydroxy-3-methylglutaryl-CoA reductase activity in cultured human fibroblasts by very low density lipoproteins of subjects with hypertriglyceridemia.

Very low density lipoproteins (VLDL) and low density lipoproteins (LDL) from human normolipemic plasma, and the VLDL, the intermediate density lipoprotein (IDL), and LDL from patients with Type III hyperlipoproteinemic plasma were tested for their abilities to suppress the activity of 3-hydroxy-3-methylglutaryl-Coenzyme A (HMG-CoA) reductase in cultured human fibroblasts from normal subjects and a Type III patient. Regulation of cholesterol synthesis in the fibroblasts of a patient with Type III hyperlipoproteinemia appears to be normal. VLDL from normal subjects, isolated by angle head ultracentrifugation (d < 1.006) or by gel filtration on BioGel A-5m, were about 5 times less effective than LDL in suppressing HMG-CoA reductase activity, based on protein content, in agreement with previous reports with normal fibroblasts. Zonal centrifugation of normal VLDL isolated by both methods showed that the VLDL contained IDL. Normal VLDL from the angle head rotor, refractionated by the zonal method, had little, if any, ability to suppress the HMG-CoA reductase activity in either normal or Type III fibroblasts. VLDL, IDL, and LDL fractionated by zonal ultracentrifugation from Type III plasma gave half-maximum inhibition at 0.2-0.5 mug of protein/ml, indistinguishable from the suppression caused by normal LDL. Type III VLDL did not suppress HMG-CoA reductase in mutant LDL receptor-negative fibroblasts. Zonally isolated VLDL obtained from one Type IV and one Type V patient gave half-maximal suppression at 5 and 0.5 mug of protein/ml, respectively. Molecular diameters and apoprotein compositions of the zonally isolated normal and Type III VLDL were similar; the major difference in composition was that Type III VLDL contained more cholesteryl esters and less triglyceride than did normal VLDL. The compositions and diameters of the Type IV and Type V VLDL were similar to normal VLDL. These findings show that the basic defect in Type III hyperlipoproteinemia is qualitatively different from the cellular defect found in familial hypercholesterolemia, since the regulation of HMG-CoA reductase activity is normal in Type III fibroblasts. The metabolic defect in hypertriglyceridemia is related to the triglyceriderich lipoproteins which, free of other lipoproteins, have an enhanced ability to interact with cultured fibroblasts to regulate HMG-CoA reductase activity. These studies suggest that, in hypertriglyceridemia, there is a mechanism for direct cellular catabolism of VLDL which is not functional for normal VLDL.

Thermally induced myocardial preservation and necrosis in deprived fetal mouse hearts.

Cultured fetal mouse hearts deprived of oxygen and glucose were used to examine the effect of temperature on the mechanical, biochemical, and ultrastructural responses of the deprived myocardium to assess the utility of this in vitro model for studying myocardial necrosis, preservation, and repair. After 4 h of deprivation at 4, 24, 37, or 42 degrees C, 1) beating had ceased;2) ATP levels were decreased by 22% for 4 degrees C insults, 69% for 24 degrees C, 89% for 37 degrees C, and 97% for 42 degrees C; 3) CPK and LDH levels were unchanged; and 4) ultrastructural changes were observed. After 24 h of recovery from deprivation, 1) beating resumed, except for 42 degrees C;2) ATP levels were 102% of control for 4 degrees C; 99% for 24 degrees C; 62% for 37 degrees C; and 4% for 42 degrees C; 3) LDH content was decreased by 0% at 4 degrees C; 6% at 24 degrees C; 35% at 7 degrees C; and 70% at 42 degrees C; and 4) CPK content decreased similarly. Hypothermia protected deprived myocytes while hyperthermia accelerated cell necrosis. Combining deprivation with thermal insult in this in vitro model provides a spectrum of myocardial damage for studying the effect of interventions on repair processes and on metabolic changes in jeopardized myocardium.