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Biomedical subjects

R Olinescu

Publications and source records attributed to R Olinescu.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

The levels of bilirubin may be related to an inflammatory condition in patients with coronary heart disease.

In agreement with previous reports, we found that the bilirubin level is significantly lower in the blood of patients with coronary heart disease (CHD) than in age and sex matched controls. However, we found that the level of bilirubin in the blood seemed to be an age-dependent phenomenon and closely related to the activation of leukocytes. In 1,000 cardiac catheterised patients from Urbana, USA suffering from CHD, the level of blood bilirubin was found to be lower than in age and sex-matched controls. The same results were obtained on 300 patients with acute ischemia from three hospitals from Bucharest, Romania. The activation of polymorphonuclear leukocytes increased in the catheterised patients, as well in Romanian patients. An activation of leukocytes triggered by a chronic inflammatory process may increase the lysis of erythrocytes. The erythrocytes of patients with 100% stenosis exhibited a higher rate of in vitro lysis in the presence of activated leukocytes and homocysteine. The increased hemolysis may trigger the activation and removal of the resulting bilirubin from blood. Such a mechanism may depend on the liver clearing function. This function was decreased in catheterized patients over 60 years of age, but had accelerated in younger patients. An individual variation in liver function may explain the widespread bilirubin levels in the blood of patients suffering from CHD.

Adult↗
PubMedDate not supplied

Age-dependent variations of the plasma peroxides and total antioxidants in women with obesity and hypothyroidism.

The concentrations of peroxides, total antioxidants and free sulfhydryl (SH) groups in the plasma of normal persons vary depending on age and sex. The most significant differences for peroxides were found between young and old people over 60 years in both sexes. For the SH groups, significant differences were observed only between young and older women, while in men, similar differences were found only for total antioxidants. In women, the association of obesity with hypothyroidism induces a significant increase of peroxides even at the age of 35 years. This significant increase goes in parallel with a increase of uric acid and a decrease of the total antioxidants. Considering the inclusion of uric acid and of free SH groups among the natural antioxidants, the changes observed in obesity associated with hypothyroidism may suggest a tendency of an adaptation of the organism since hypothyroidism favors the peroxidation of lipids. Up to a certain age, varying according to the individuals, the rise of lipid peroxides is compensated by the increase of certain antioxidants, especially of uric acid.

Adult↗
PubMedDate not supplied

Induction of chemiluminescent emission in polymorphonuclear leucocytes stimulated by Sendai virus.

Sendai virus (SV) stimulates in vitro the chemiluminescent emission (CHL) of human polymorphonuclear leucocytes (LPMN). The kinetics of CHL produced by LPMN depends on the structure of stimulus, the intensity being dependent of the immunological status of the subject. CHL induced by Sendai virus is similar to that given by phorbol-myristate (PMA) as regards the induction of an early maximum. To obtain CHL significant emission, an optimum ratio between LPM concentration and Sendai virus dilution is required. The maximum effect is obtained in a large scale of dilution of Sendai virus ranging from 6,000 to 16,000 uHA.

Cells, Cultured↗
PubMedDate not supplied

Antiviral activity of some copper complexes of symmetrical triazines.

Copper complexes of hydrazones derived from symmetrical triazines inhibit the multiplication of three different types of viruses (Sendai, HSV and VSV) showing as well a scavenger activity on O2- radicals. The results emphasize the antiviral activity of these complexes which have at the same time a O2- radical scavenger activity.

Antiviral Agents↗
PubMedDate not supplied

Variations of peroxides and total antioxidants from the plasma of normal blood donors, as a function of sex, age and blood group.

The level of peroxides and total antioxidants in normal individuals varies with sex, age and the type of blood group. The most significant differences were noticed in peroxide between young and aged subjects (over 60) of both sexes. For the free SH groups, significant differences were found, only in women, in whom it decreased with age. Similar changes were observed in men for the total antioxidants. High peroxide values were observed in donors with blood group 0-I and the lowest levels appeared in subjects with blood groups A and B, in parallel with increased values of total antioxidants. The latter results might be correlated with recent data on favourable prognosis in cancer related to the expression of group A antigens, as well as with the involvement of the glycoproteins in the characterization of blood groups (AB0 system). Our data could also be correlated with the preventive role of antioxidants in the etiology of cancer.

Adult↗
PubMedDate not supplied

Comparative study of the variations of the phagocytic capacity of polymorphonuclear leukocytes and of total plasma antioxidants in patients with pneumoconioses and lung cancer.

A comparative, preliminary study of the phagocytic capacity of polymorphonuclear leukocytes, and of the total plasma antioxidants was carried out in a group of workers professionally exposed to mineral dusts and in a group of patients with lung cancer. Both groups exhibited advanced respiratory failure stages II and III. The phagocytic capacity of polymorphonuclear leukocytes was found significantly increased in workers with pneumoconioses and moderately increased in patients with lung cancer. On the other hand, the peroxides and total plasma antioxidants exhibited great individual variations. Thus in lung cancer it was observed that peroxides had a tendency to decrease and antioxidants to increase. The individual study of the variations of these three parameters might be able to differentiate the reversible from the irreversible stages of the respiratory changes.

Adolescent↗
PubMedDate not supplied

The changes of peroxides and total antioxidants in the plasma of patients who received 131I therapeutically.

Fifty patients with thyroid cancer were studied during administration of high doses of 131I (5-50 mCi). Peroxides, total antioxidants and free sulphydryl-groups were measured in the blood samples obtained before and after administration of radioactive iodine. After the administration of iodine, significant increases of peroxides and free SH groups were observed, as well as the decrease of total antioxidants. These biochemical changes were in agreement with significant decreases of blood platelets and lymphocytes. The data obtained brought forward again the much debated problem of peroxidation and antioxidants in cancer, since comparatively, the patients with other localizations of tumors presented decreases of peroxides and variable amounts of antioxidants. The influence of iodine and thyroid hormones is discussed, with reference to a previous paper in which high levels of peroxides had been found both in hyper- and in hypothyroidism but with different mechanisms. The biochemical changes observed in the patients treated with radioactive iodine confirmed the involvement of peroxides in the consequences of internal irradiation.

Adult↗
PubMedDate not supplied

Effects of some prostaglandins on the main phosphorylating, electron transporting and peroxidative systems of the erythrocyte membrane.

Investigations regarding the main biochemical systems of the erythrocyte membrane were performed on rat erythrocyte ghosts after treating the animals with PGA1, PGE1 and PGF2alpha. These investigations have shown that the prostaglandins which were found to induce changes in the erythrocyte flexibility (PGE1 and PGF2ALPHA) also induce significant changes in the concentrations of lipid peroxides, SH groups, proteins and nicotinamide adenine nucleotides, as well as in the activity of some electron transportors belonging to the nicotinamide proteins, in the erythrocyte membrane.

Adenine Nucleotides↗
PubMedDate not supplied

The levels of bilirubin may be related to an inflammatory condition in patients with coronary heart disease.

In agreement with previous reports, we found that the bilirubin level is significantly lower in the blood of patients with coronary heart disease (CHD) than in age and sex matched controls. However, we found that the level of bilirubin in the blood seemed to be an age-dependent phenomenon and closely related to the activation of leukocytes. In 1,000 cardiac catheterized patients from Urbana. USA suffering from CHD, the level of blood bilirubin was found to be lower than in age and sex-matched controls. The same results were obtained on 300 patients with acute ischemia from three hospitals from Bucharest, Romania. The activation of polymorphonuclear leukocytes increased in the catheterized patients, as well in Romanian patients. An activation of leukocytes triggered by a chronic inflammatory process may increase the lysis of erythrocytes. The erythrocytes of patients with 100% stenosis exhibited a higher rate of in vitro lysis in the presence of activated leukocytes and homocysteine. The increased hemolysis may trigger the activation and removal of the resulting bilirubin from blood. Such a mechanism may depend on the liver clearing function. This function had decreased in catheterized patients over 60 years of age, but had accelerated in younger patients. An individual variation in liver function may explain the widespread bilirubin levels in the blood of patients suffering from CHD.

Adult↗
PubMedDate not supplied

Evaluation of the therapeutic efficiency of Voltarene by using the in vitro chemiluminescence emitted by leukocytes polymorphonuclear.

It is known that antiinflammatory drugs inhibit the chemiluminescence produced by polymorphonuclear leukocytes (PMNL). In this respect, we studied in vitro, in standardized conditions (1.0 x 10(6) PMNL), the inhibitory effect of Voltarene on the chemiluminescence produced by PMNL from patients with rheumatic diseases, before and after treatment with the above drug. The stimulation index, as a quantitative measure of PMNL phagocytosis is higher in patients with rheumatic diseases than in controls. After treatment with Voltarene, the stimulation index further increases, especially in the patients with arthritis, suggesting a raised PMNL reactivity. A great differentiation of the in vitro inhibitory effect of Voltarene was observed especially for higher concentrations, function of age and the severity of disease. According to our results, Voltarene acts mainly by increasing the PMNL reactivity. The in vitro inhibitory effect of Voltarene on PMNL seems to be correlated with the in vivo action, the younger patients showing the greatest reactivity.

Adolescent↗
PubMedDate not supplied

The significance of the peroxides increase in the plasma of the patients with liver failure.

200 patients with varied types of liver failure were biochemically and clinically investigated. Beside the usual biochemical analyses (transaminases, glutamyl transpeptidase, triglycerides, bilirubin), some special parameters such as lipid peroxides, glutathione, ceruloplasmin and the total antioxidative capacity of plasma were measured. High levels of lipid peroxides appear especially in severe cases of liver failure such as acute viral hepatitis, coma. The persistence of a high level of peroxides in plasma suggests the presence of severe, irreversible lesions. The increase of peroxides in the plasma is mainly due to the overridden production of antioxidative systems, localized especially in the liver. In severe liver failure, the mechanism of the increased formation of peroxides seems to involve bilirubin, due to induction of liver heme oxygenase. The data presented showed inverse correlations between the increase of peroxides and the decrease of glutathione and ceruloplasmin.

Alanine Transaminase↗
PubMedDate not supplied

Biochemical mechanisms involved in the hepatotoxicity of some drugs.

To find out the biochemical mechanisms involved in the hepatotoxicity of certain drugs, the continuous evolution of some related biochemical parameters was investigated. The results obtained showed the decrease of cytochrome P450, glutathione (GSH) and aniline hydroxylase, as well as increases of lipid peroxides and tryptophan oxygenase 2 hours after i.p. administration of carbon tetrachloride (CCl4) and paracetamol. Characteristic changes of hepatotoxicity such as increase of blood glutamate-pyruvate transaminase (GPT) and triglycerides, and decrease of free sulfhydryl (SH) groups were observed 24 hours after drug administration. The peroxidation of microsomal lipids appears to be the biochemical mechanism involved in the acute administration of these drugs. Subsequently this peroxidation leads to morphologic hepatic changes. In our experimental conditions, hepatotoxicity was prevented by concomitant administration of cystamine.

Acetaminophen↗
PubMedDate not supplied

The antioxidative action of fibrinogen and the implications of this effect on platelet aggregation.

Purified fibrinogen strongly acts as an antioxidant by inhibiting the chemiluminescent emission developed in vitro, in a cell-free system composed of luminol and hydrogen peroxide. The antioxidative action of fibrinogen depends directly on its concentration, even in the presence of human serum. On the other hand, the platelet aggregation is an important source of oxygen free radicals. These radicals can also be measured by chemiluminescence, when the platelet aggregation is triggered by arachidonic acid. In a platelet suspension, fibrinogen inhibits both aggregation and the associated chemiluminescent emission. A possible correlation between the plasma level of lipid peroxides and fibrinogen was studied in different groups of patients, mostly with cardiovascular diseases and neoplasms. A weak correlation was found only in cardiovascular diseases, in which the tendency of fibrinogen increase could also be interpreted as an antioxidative action of peroxidation restriction, especially in ischemic conditions. In neoplasms, this correlation could not be found, in spite of the high level of fibrinogen associated with a decrease of peroxide formation, a characteristic feature of tumoral growth due to the change of fatty acids nature in the cellular membranes.

Adult↗
PubMedDate not supplied

Estimation of oxidative stress in cardiovascular diseases.

Patients with mild and severe cardiovascular diseases showed a significant disturbance of the redox equilibrium, manifested by increases of lipid peroxides and decreases of plasma total antioxidants. When the resulting oxidative stress is associated with ECG changes characteristic of "coronary disease" it indicates an acceleration of atherosclerosis, in the initial phase (cellular involvement, migration, proliferation) and an additional thrombogenic risk in the "ischemic phase". When oxidative stress is associated with chronic heart failure, it indicates a progressive form with replacement fibrosis. These data suggest the necessity of adding to the usual therapy antioxidants, that reduce the oxidative stress, may slow down the pathologic changes and improve the patient's homeostatic systems.

Adult↗
PubMedDate not supplied

Steroid hormones may modulate the chemiluminescence emission produced by polymorphonuclear leukocytes.

Steroid hormones, testosterone and estrone may modify the in vitro chemiluminescence (CL) produced by polymorphonuclear leukocytes (PMNL) during phagocytosis. These changes (increases or decreases) depended on the age and health condition of the donor, but not on sex. Generally, these steroid hormones increase the PMNL CL emission at concentrations lower than 10(-5) M, but decrease it at higher levels. In an acellular system, using the same CL technique, these hormones exhibit an opposite effect, by increasing the emission at higher concentrations. As the PMNL induced CL emission is a membrane-dependent process, strongly related to phagocytosis, the action of steroid hormones seems to be due to the receptors on the surface of leukocytes. In both systems, cellular and acellular, the effect of steroid hormones on the CL emission also depends on the concentration of hydrogen peroxide added or released during phagocytosis. The modulatory action of steroid hormones on phagocytosis may occur in certain conditions, such as infections diseases and hormone disturbances in the course of which there occurs a significant release of oxygen free radicals, concomitantly with variations of the levels of steroid hormones.

Adolescent↗
PubMedDate not supplied

On the significance of chemiluminescence induced by the blood polymorphonuclear leukocytes. I. Normal values.

In spite of the fact that chemiluminescence (CL) produced by the in vitro stimulated polymorphonuclear leukocytes is now a current method for the quantitative measurement of phagocytosis, its clinical use is still limited due to some controversies mostly technical. By comparing the different forms of presentation of the results, we proposed as stimulation index, the ratio of CL in the stimulated sample to that in the nonstimulated as measured at the same time interval and in the same number of cells (1 x 10(6)/ml). Measurements performed in a group of 200 healthy individuals, aged 20-70 years, with various occupations showed wide large variations of both the stimulation index of 23.5 +/- 12.3 and in a lesser degree of the CL kinetics. We suggest different possibilities of interpretation of the results obtained by this method (both the stimulated index and the CL kinetics) in order to obtain maximum information concerning the cellular immunity for clinical use.

Adult↗