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Biomedical subjects

M Frass

Publications and source records attributed to M Frass.

125 records · Page 7Linked to original sources

[The esophageal tracheal Combitube (ETC): animal experiment results with a new emergency tube].

Prompt and effective ventilation, essential for patients with cardiopulmonary arrest, may be provided by a new airway for emergency resuscitation. The "Esophageal Tracheal Combitube (ETC)" offers endotracheal or esophageal obturator ventilation according to choice. Ventilation is therefore always possible after blind intubation. Experimental studies in dogs showed encouraging results during oesophageal placement of the ETC; blood gas analyses and cardiovascular parameters, in particular, were comparable to conventional endotracheal ventilation. Satisfying results were achieved during routine surgical operations in humans. We intend to use the ETC as a device for emergency cardiopulmonary resuscitation in humans. It is especially suitable for medical personnel not trained in endotracheal intubation. The ETC has been conceived to bridge the gap of the prehospital phase.

Animals↗

Role of beta-endorphins in silent myocardial ischemia.

The reason for the absence of pain perception in silent myocardial ischemia is unknown. A role of increased endorphinic activity in patients with silent ischemia has been postulated. To further investigate this hypothesis, 10 men with documented coronary artery disease and previous positive electrocardiographic findings during exercise without anginal pain were studied. Six healthy volunteers served as control subjects. The protocol included 2 bicycle exercise tests, the first test serving as baseline and the second performed after administration of naloxone, a specific opiate antagonist. Plasma beta-endorphin levels were measured by radioimmunoassay in both tests at rest, at peak exercise level and after recovery. All patients underwent thallium-201 scintigraphy after coronary vasodilation to provide an additional independent marker of ischemia. All patients showed stress-induced reversible perfusion abnormalities. No patient reported pain after naloxone application. Exercise duration, blood pressure and heart rate were not significantly altered by naloxone. Plasma beta-endorphin levels ranged from 18 +/- 6 pg/100 microliters (mean +/- standard deviation) at rest to 22 +/- 6 pg/100 microliters during exercise in the patient group and from 20 +/- 5 to 27 +/- 9 pg/100 microliters in the control subjects. Thus, there was no significant increase of plasma beta-endorphins during exercise or after naloxone administration, nor was there any difference observed between patients and control group. These data support the view that endorphinic activity does not play an essential role in the pathophysiology of silent myocardial ischemia.

Blood Pressure↗

[R spike potentials in ergometric stress: patients with dilated cardiomyopathy in comparison to coronary heart disease].

R-wave amplitude changes during exercise were compared in patients with cardiomyopathy (n = 32), patients with coronary artery disease (n = 58) and controls (n = 12). Patients with cardiomyopathy (CMP) had a smaller R-wave amplitude (RWA) at rest than those with coronary artery disease (CAD). At comparable levels of exercise patients with CMP showed no change in RWA, while those with CAD demonstrated an increase in RWA. Controls showed a decline in RWA. In patients with CAD changes in RWA during exercise were more sensitive in the detection of disease than ST-segment changes. Left ventricular function was the major determinant of the direction and magnitude of RWA changes both in patients with CMP and CAD, with lesser changes in RWA in patients with more severely reduced left ventricular function.

Blood Pressure↗

[Comparison of the renal ultrasound-furosemide test with the isotope nephrogram. Possible clue to the retention phenomenon?].

In 23 patients with essential hypertension renographic and sonographic examination of the kidneys was compared. No correlation could be observed for functional parameters and urinary excretion between the two different methods. Correlations have only been detected between renographic retentions and furosemide-conditioned swelling of the kidneys in sonography: patients with severe retention showed a statistically significant stronger response to furosemide. The increased retention in the renal pelvis could be responsible for alterations in sonographic findings. This study provides new data on the mechanisms of retention, whereby retention in the renal pelvis in some patients seems to be most probably caused by nephrosclerosis.

Adult↗

Continuous pump-driven hemofiltration associated with a decline in alpha-atrial natriuretic peptide.

The levels of alpha-atrial natriuretic peptide (ANP) in the right atrium, pulmonary artery, radial artery, and superior vena cava plasma were measured by radioimmunoassay in eight patients with volume-expansion due to different diseases. The alpha-ANP levels were significantly increased, but became decreased after fluid removal by continuous veno-venous hemofiltration. When all alpha-ANP concentrations of different anatomical locations and hemodynamic variables were grouped, pulmonary capillary wedge pressure correlated significantly with all alpha-ANP groups, whereas right atrial mean pressure correlated with alpha-ANP levels in pulmonary artery plasma only. Alpha-ANP concentrations were distinctly lower in superior vena cava plasma than in plasma from the right atrium, pulmonary artery, and radial artery. Since alpha-ANP plays an important role in the homeostasis of sodium and fluid balance, measurement of alpha-ANP concentrations, particularly in right atrium, pulmonary artery, or radial artery plasma, might provide valuable information on the status of the critically ill.

Adult↗

Primary multiple colonic carcinoma.

Polypoid lesions of the colon are commonly accepted risk factors for the development of carcinomas of the colon. Fifty-two of 266 patients with one or more polypoid lesions of the colon showed a carcinoma in one of the polyps, 6 patients had a second carcinoma. Our study demonstrates the importance of preoperative investigation of the total colon in patients with carcinoma of the colon. Furthermore, the necessity of total exstirpation of each polypoid lesion is discussed.

Adenocarcinoma↗

Plasma levels of atrial natriuretic peptide (ANP) in volume expanded patients: response to fluid removal by continuous pump driven hemofiltration.

Circulating amounts of human atrial natriuretic peptide (hANP) are elevated in congestive heart failure and renal failure. Stretching of cardiac atria, due to volume expansion associated with these diseases, is widely accepted to be the predominant stimulus for release of the hormone. Measurements of hemodynamic parameters as well as plasma concentrations of ANP in the right cardiac atrium, pulmonary artery, radial artery and vena cava superior, before and after continuous veno-venous hemofiltration (CVVH) of critically ill volume expanded patients, proved that ANP might be a useful indicator of fluid balance in these patients.

Atrial Natriuretic Factor↗

The role of alpha-atrial natriuretic peptide in fluid retention during mechanical ventilation with positive end-expiratory pressure.

Although controlled mechanical ventilation (CMV) with positive end-expiratory pressure (PEEP) has a central place in the treatment of acute respiratory failure (ARF), several side effects of this technique have to be faced. CMV with PEEP may induce pulmonary barotrauma, disturbance of cardiac performance, impairment of renal function and fluid retention. Atrial natriuretic peptides (ANP) are released from the atria upon stretching and play a major role in the control of sodium and fluid balance. Therefore it was logical to determine plasma levels of alpha-ANP in CMV. A study performed in 7 patients suffering from ARF suggested that alpha-ANP plasma levels were depressed during PEEP at 15 cm H2O in comparison with PEEP at 0 cm H2O (ZEEP). The decrease in plasma levels of alpha-ANP was evident in samples taken from superior vena cava, right atrium, pulmonary artery and radial artery as well. The decrease in alpha-ANP was associated with a decline in cardiac index, creatinine clearance, urinary output and urinary sodium excretion. Experiments in volume- expanded healthy volunteers also suggest that CMV with PEEP is able to depress plasma levels of alpha-ANP. The reasons behind the decline in release of alpha-ANP may be atrial compression by the distended lungs and the well-known reduction of venous return to the heart. Other possible factors promoting fluid retention during CMV with PEEP are the decrease in cardiac index and glomerular filtration rate, changes in intrarenal distribution of blood flow, and a stimulation of release of antidiuretic hormone via stretch receptors in the left atrium and baroreceptors in aorta and carotid arteries.

Animals↗

Adenine metabolism in erythrocytes of patients with Duchenne muscular dystrophy.

The primarily metabolic defect in Duchenne muscular dystrophy (DMD) is still unknown. In addition to the disturbance of muscle cell and erythrocyte membranes of patients with DMD an impairment of purine metabolism has been suggested on the basis of the decreased ATP content of the muscle fibers. To avoid the leakage of adenine nucleotides from cells, allopurinol has been administered to DMD patients to increase the formation of adenine nucleotides via the salvage pathway. The purpose of this study was to investigate this hypothesis of an effect of allopurinol on the formation of adenine nucleotides. Furthermore, the clinical status of allopurinol-treated DMD patients was examined. Biochemical studies were performed on erythrocytes of 19 patients with DMD, and adenine nucleotide concentrations and the incorporation of 14C-adenine into purine nucleotides were assessed before and after 6 months of allopurinol therapy. No improvement of the clinical status could be observed, although a slight increase in ATP formation was seen.

Adenine↗

[Laboratory findings in the "Vienna Health Study 79" (author's transl)].

In the course of a health study carried out 1979 in Vienna on more than 2,500 persons at the age of 25, 40 and 60 years respectively, the following blood parameters were investigated: erythrocytes, hemoglobin, hematocrit, serum iron, OGTT, HbA1, uric acid, cholesterol, HDL-cholesterol, SGOT, SGPT, AP, creatinine, BUN; furthermore the usual clinical urine findings. Results are exposed and discussed.

Adult↗

Heat inactivation of plasma hydrolases as a means of discriminating between the genotypes in cystic fibrosis: the experience in Israel.

The ability to discriminate between cystic fibrosis (CF) patients, carriers and control subjects, by determining the degree of hear inactivation of certain plasma enzymes has recently been reported. Material from Israel on 39 patients, 68 carriers and 65 control subjects, was tested under the originally described conditions with concordant results and distinct separation of the three genotypes. No carriers were detected in the 65 control subjects, perhaps because of the dilutional effect of those ethnic groups in Israel among whom the frequency of the CF gene is known to be rare. Biochemically, no evidence of heterogeneity of CF was found among the various ethnic groups.

Acid Phosphatase↗

Purine metabolism of erythrocytes in myotonic dystrophy.

The uptake and subsequent metabolism of adenine and adenosine was studied with the intact erythrocytes of patients with myotonic dystrophy (MD). Washed erythrocytes of both controls and patients were incubated with 14C-labeled adenine or adenosine at 20 degrees C for 5 to 120s to characterize the uptake process. No differences in the uptake process of adenine or adenosine were observed between normal and MD erythrocytes. Formation of adenine nucleotides was determined at 37 degrees C after incubation for 30 min. Compared to controls, the incorporation of adenine into adenine nucleotides was 2.6 times higher in MD erythrocytes. This depends mainly on an increase of ATP formation. The mean ratios of ATP:ADP + AMP for normal red cells and MD erythrocytes were 0.92 and 1.39 respectively. No difference was found in the conversion of adenosine to adenine nucleotides. In spite of a normal amount of intracellular ATP a greater demand for ATP exists. This might be due to leakage of adenine nucleotides out of MD erythrocytes.

Adenine↗

Effects of garlic extract (Allium sativum) on neutrophil migration at the cellular level.

Studies of the effects of garlic extract on oxidative and lipoprotein levels have yielded widely different findings. Leukocytes play an important role during many processes, including inflammation. They migrate from intravascular spaces into tissues and attack microorganisms. In a recent study, the inhibitory effects of the nonsteroidal antiinflammatory drug, ibuprofen, on leukocyte transmigration were demonstrated using an in vitro assay. Little is known about the cellular effects of garlic extracts (Allium sativum). The aim of the current study was to investigate the influence of garlic extract on leukocyte migration through endothelial cell monolayers and thereby evaluate a possible role in inflammatory processes. Human umbilical endothelial cells were cultured on microporous membranes to make an endothelial cell monolayer (ECM). Freshly isolated neutrophils were used in a recently described migration assay. The amount of untreated neutrophils migrating through the untreated ECM was used as control and set at 100%. Neutrophils and/or ECM were pretreated with garlic extract using moderate, higher, and lower concentrations. Moderate plasma concentrations of garlic extract inhibited neutrophil migration through ECM significantly (64 +/- 5.8% standard deviation [SD]; P < 0.05) when both cell types were treated, (a situation that may have clinical relevance). Treating either neutrophils or ECM alone showed significant reductions in migratory rate (neutrophils treated alone: 81 +/- 7.7% SD, P < 0.05; ECM alone: 70 +/- 6.7%, P < 0.05). Thus, garlic extract is identified as a potent inhibitor of leukocyte migration through endothelial cell monolayers. Treatment of both cell types has an additive effect. Endothelial cells seem to be more affected than neutrophils. Further investigations are necessary to understand the potential clinical consequences.

Cell Adhesion↗