Isolated ventricular noncompaction in patients with chronic renal failure.

Isolated ventricular noncompaction is a rare congenital disorder characterized by the presence of numerous prominent trabeculations and deep intratrabecular recesses which communicate with the ventricular cavity. This disease has a very bad prognosis. Two cases of isolated ventricular noncompaction in patients with chronic renal failure have been described. The first case is a 65-year-old male, on regular hemodialysis for 3.5 years due to mesangioproliferative glomerulonephritis. He was symptomless regarding signs of congestive heart failure, angina pectoris, systemic embolization or arrhythmia. The second case is a patient with chronic renal failure (due to renal calculosis) admitted because of non-ST elevation acute myocardial infarction. In both cases echocardiography revealed an enlarged left ventricle, with extremely thickened walls with two layers: a thin, compacted myocardium on the epicardial side, and a thicker noncompaction endocardial layer. Ratio between noncompaction part of the wall and compaction part was 2.56 in the first and 4.94 in the second case. Blood flow from the left ventricular cavity into recesses was recorded with Color Doppler. Oral anticoagulation therapy was introduced in both of them. Holter ECG in the first patient revealed an intermittent right bandle branch block and in the second patient, premature ventricular contractions. Neurological examination findings were normal in both patients. Echocardiography of first-degree relatives was performed in the first case and it was normal in all 5 relatives. In the second case it was not performed due to technical reasons (relatives live abroad). Regular echocardiographic follow-up of all patients with chronic renal failure is necessary in order to diagnose cardiovascular comorbidities including this rare abnormality and its complications.

[Echosonography in diagnostics of carotid artery disease].

Color duplex scanning is important method in diagnostics of carotid stenosis disease (CSD). This method is accurate in estimation of stenosis degree and plaque quality characteristics as potential source of embolus. It enable the approach to extracranial as mostly affected segments of carotid arteries, frequent follow up of asymptomatic clinical course of the disease and inspection in local chemodynamic flow parameters. Beside numerous advantages, in cases of severe degree stenosis of echolucent or heterogeneous calcificant plaques, estimation of stenosis degree is inaccurate and than the use maximal flow velocities for stenosis degree estimation is better. Unfortunately in this situation some local carotid changes like multiple carotid plaques, significant proximal or distal concomitant stenosis as well as some disease like arterial hypertension, aortic valve disease, arrhythmia absoluta etc. may over or underestimate the stenosis degree, and thus make impossible the right diagnosis.

Quinidine-induced inhibition of leukocyte esterases.

We have demonstrated the feasibility of a system based on image processing to measure enzyme activity inside morphologically classified individual cells. When used in this system, quinidine inhibited naphthol AS-D chloroacetate esterase in polymorphonuclear neutrophils and alpha-naphthyl acetate esterase and alpha-naphthyl butyrate esterase in monocytes. These effects were dependent on the duration of exposure and on drug concentration. Dose-effect relationships were established and the concentration at which 50% inhibition (ID-50) occurred was used as a reference point to compare the toxicity of different compounds. Chloroquine, primaquine, and quinine (which, like quinidine, possess a quinoline ring) also affected the esterases, but had no effect on several other enzymes. Neostigmine inhibited the esterases we studied but only at a very high concentration. Various chemicals inhibited the enzymes within the cells, as has been demonstrated for the enzymes in plasma.

Quinidine-induced decrease of intracellular esterase activity in a hepatoma cell line.

Using image-analyzing equipment, we measured the effect of quinidine on the activity of naphthol AS-D chloroacetate esterase, alpha-naphthyl butyrate esterase, alpha-naphthyl acetate esterase, and acid phosphatase in individual cells of a human Hep G2 hepatoma cell line. The impact of the drug on the morphology of the cells was also observed. Depending on the concentration of quinidine applied, various changes occurred, the most extreme being cell death. However, at some drug concentrations that did not appear to affect visible cell structures, the activity of the esterases was decreased. This lessened enzyme activity did not seem to be related to the enzymes leaking from the cells, because the activity of acid phosphatase was unaffected. Inhibition of the esterase activity was related to the interval of exposure to quinidine in the perfusing medium and to the concentration of the drug. We consider the system described here to be a potential replacement for experiments with animals in the study of hepatotoxicity.

Simplified methods for measuring enzyme kinetics in a single cell.

We discuss techniques for measuring myeloperoxidase activity cytochemically in isolated polymorphonuclear neutrophils. We have used a sophisticated scanning microdensitometer as a reference device and compared results obtained by Zeiss Ultraphot III B and Reichert Zetopan microscopes with those of the scanning microdensitometer. We made both end-point and kinetic measurements, using conventional microscope slides and a special incubation chamber. Some resolution is lost with simpler microscope systems, but they provided results sufficiently like those obtained with the scanning microdensitometer that they could be used in the clinical laboratory to allow investigation of enzyme activity in single cells.

Device for quantitative cytochemistry: a computerized scanning microdensitometer 'grain counter'.

A computerized scanning microdensitometer and autoradiographic grain counter was able to provide quantitative data on the cytochemical final reaction product formed within a single cell and also quantitate the kinetics of its formation. Optical density and area measurements were performed on hundreds of leukocytes from slides previously stained to demonstrate any one of a variety of reactions. These included cellular glycogen, lipids, peroxidase, esterases, alkaline phosphatase, and acid phosphatase. In addition to these slide studies, chamber studies with an adapted Dvorak-Stotler Chamber allowed the measurement of enzyme kinetics within single cells.