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Biomedical subjects

R Olinescu

Publications and source records attributed to R Olinescu.

At least 19 recordsLinked to original sources
PubMed2005

Significant modification of lipid metabolism in aged persons following the treatment with a nutritive supplement containing embryonary peptides--preliminary results.

HUMANOFORT is a nutritive supplement extracted and purified from embryonated chicken eggs according to an original procedure under licence. Humanofort received the suitable consent from the Romanian Ministry of Health. The main components of Humanofort are two oligopeptides of 5,000 and 10,000 D molecular weight. 40 subjects aged 50-75 years (18 men and 22 women) consumed, daily, 4 caps of Humanofort for 60 days. The samples of blood from each subject were obtained before and after treatment. Therefore, each subject was his own control. In all subjects, after treatment, total cholesterol and LDL-cholesterol decreased approximately 30% as compared with the initial values. In 80% of patients, an increase of HDL cholesterol and a decrease of the insulin level in blood were also observed. After treatment, the cardiac risk factors (Aethna 2000 Program), such as total cholesterol/HDL and Apolipoproteins B/A were shifted towards lower range. These long-lasting modifications have an adaptative-regulatory character and seem to be produced by the growth factors contained in Humanofort.

Aged↗
PubMed2002

The formation of oxidative stress condition in the experimental chemically induced hepatotoxicity.

In spite of extensive studies concerning the chemically induced hepaototoxicity, no clear-cut practical conclusions were obtained. Wide chemical structure of compounds as well as the different way of administration are the most important factors. We used an acute administration of carbon tetrachloride and paracetamol and a chronic intoxication with acetylphenylhydrazine, cadmium chloride and ethanol. For the acute administration of chemicals in high doses, in the rat liver microsomes a decrease of cytochrome P450, aniline hydroxylase and glutathione (GSH) was noticed with an increase of lipid peroxides even at 2 hours after administration. 24 hours after the chemicals administration, in the blood of rats characteristic changes of hepatotoxicity such as increases glutamate-pyruvate transminase, triglycerides and lipid peroxides, while GSH was decreased. In chronic administration, the cummulated concentration of chemical was true main factor. For both ways of chemicals administration, as a critical concentration was reached, an oxidative stress was produced, demonstrated by the increase of lipid peroxides and subsequently decrease of GSH. In both ways of administration, the oxidative stress was the precocious biochemical event occurring even at 2 hours and it triggers other metabolic changes which favor fatty infiltration and liver damage.

Acetaminophen↗
PubMed2000

Stimulatory effect of some plant extracts used in homeopathy on the phagocytosis induced chemiluminescence of polymorphonuclear leukocytes.

Some plant extracts on a large range of dilutions as used in Homeopathy were tested on the chemiluminescence emission produced by polymorphonuclear leukocytes. The high stimulatory action was noticed when extracts from Uvae Ursi and Saponaria were tested, as the classical effect exerted by zymosan was exceeded. A moderate stimulatory action comparable with that of zymosan was found when extracts from Echmaceea, Aleo and Prumis were used, as well as in the case of Propolis. The relationship between stimulatory effect and the concentration range is modulated as function of the extract source, several peaks being observed for some dilutions (Saponana), but generally no quantitative relations were obtained. By studying the time when a chemiluminescence peak was observed, it is possible to estimate wether the weight of the NADPH oxidase or myeloperoxidase pathways are involved in the stimulatory effect on polymorphonuclear leukocytes.

Arctostaphylos↗
PubMed1996

The hemolytic activity of homocysteine is increased by the activated polymorphonuclear leukocytes.

Homocysteine is an accepted risk factor when its plasma level exceeds the physiological upper limit of 12 mumol/L. We found in vitro that homocysteine is able to lyse the erythrocytes (RBCs) at higher concentrations than 15 mumol/L only when activated polymorphonuclear leukocytes (PMNL) are present. The hemolytic effect of homocysteine was higher in RBCs obtained from cardiac catheterized patients with 100% stenosis of the coronary arteries. Homocysteine was also able to increase the activation in vitro of PMNLs triggered by opsonized zymosan. The hemolytic action of homocysteine was found to be dependent on the ratio of PMNLs to RBCs. This relationship may help to explain the great individual variations in the hemolytic activity noticed in blood obtained from cardiac catheterized patients, and also may explain the mild anemia in some patients suffering from cardiovascular disease.

Coronary Disease↗
PubMed1996

Direct detection of the antioxidant activity of a new flavonic derivative using the chemiluminescence method.

The antioxidant potential of a new water soluble flavonic derivative, namely theophylline rutoside (TR-1722) has been tested using the chemiluminescence method. The method is based on the oxidative degradation of luminol by the hydrogen peroxide in Tris-HCl-buffer, when reactive species of oxygen are being obtained: O2-., HO., 1O2, and allows for the capability of substances to inhibit the free radical processes in this test system to be quantified and hence for their antioxidant properties in respect to a standard substance (in our case quercetin) to be compared. The results obtained reveal that TR-1722 has antioxidant action comparable to that of quercetin, the highest efficacity being registered at the concentration of 2 mumol/l, the conditions being: H2O2 16,2 mmol/l; luminol 2 mumol/l, in Tris-HCl buffer 20 mmol/l, pH 8.3. The antioxidant potential of TR-1722 is also maintained when the conditions of the system are modified, that is, the concentration of the hydrogen peroxide, the intensity of the action being dependent on the hydrogen peroxide concentration, but no direct proportionality is registered.

Antioxidants↗
PubMed1995

Cigarette smoking causes biochemical changes in blood that are suggestive of oxidative stress: a case-control study.

Cigarette smoking has been shown to be a major risk factor for cardiovascular disease, lung cancer, and respiratory diseases. Due to its high content of oxidants, the cigarette smoke is bound to cause a prooxidant/antioxidant imbalance in the blood plasma and tissues of smokers. The study groups were selected from an apparently healthy population living in urban areas, comprising 200 subjects aged 18 to 80 years, half of whom were smokers. In smokers aged 18 to 45 years, the changes of the plasma prooxidant parameters (i.e., lipid peroxides, leukocyte activation, and the antioxidant ones [thiol concentration, total antioxidant capacity]) were not significantly different from those of the age-matched controls, whereas in the 46 to 80 age group they were. In smokers, both antioxidant erythrocyte enzymes, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), exhibited increased activity in the 18 to 45 age group and decreased activity in the 46 to 80 age group. The differences in enzyme activity between the smoking and nonsmoking groups were highly significant for SOD in all ages, whereas for GSH-Px the difference in activity was significant only in the case of older smokers. These findings would suggest that a process of adaptation takes place in younger smokers, in whom the antioxidant systems are able to counteract the oxidant factors, while in older smokers this process is no longer occurring and the plasma and tissues are under permanent oxidative stress. Our results clearly demonstrated that a prooxidant/antioxidant imbalance exists in the blood of smokers, and the determination of leukocytes stimulation index may be a useful and simple way of assessing the oxidative stress status of these individuals. A hypothesis regarding a possible mechanism linking cigarette smoking to the development of coronary heart disease is presented.

Adolescent↗
PubMed1994

Tissue lipid peroxidation may be triggered by increased formation of bilirubin in vivo.

Following the administration of phenylhydrazine, cadmium chloride and ethanol to rats there was a marked increase in the concentration of liver lipid peroxides and a sharp decline in GSH levels. The oxidative stress generated by the action of these toxic compounds led to the induction of liver heme oxygenase, which exhibited a 3-fold increase in activity over the control value. Patients with various forms of liver disorders showed increased levels of plasma lipid peroxides as well as hyperbilirubinemia. In view of the known ability of bilirubin to cause lipid peroxidation in illuminated erythrocyte membranes, the results of the present paper suggest that in severely impaired liver, as in some liver diseases, lipid peroxides may be also produced by a mechanism involving heme oxygenase.

Animals↗
PubMed1993

Redox capacity of the pineal gland in rats. Effect of castration.

The day/night cycle-induced effects, and the effect of castration on pineal oxidative potential in rats, were studied herein. Experiments were made in adult and castrated Wistar rats kept under normal light conditions during winter (on December and January). Castration was performed 72 hrs before sacrification. Groups of 6 intact or castrated animals were sacrificed at 4 hr-intervals during 24 hrs (the day/night cycle). Blood and pineal were then taken. Peroxides and total pineal antioxidants in plasma and pineal homogenate were assessed by chemiluminescence. The results obtained prove that photoperiod is involved in the organism oxidative potential, and that pineal is involved in the diurnal rhythm of this potential. Pineal peroxide and antioxidative concentrations show circadian variations with minimum and maximal values during the day or the night, which are also reflected at the plasma level. In the first half of the morning are registered increased peroxide and decreased antioxidative levels while at night the diagrams are reversed. As compared to the intact group, in the castrated one antioxidants and peroxides maintain their biorhythms but their concentrations are significantly changed. The diagram of pineal peroxides in the castrated group is situated above that of the intact one, with statistically significant differences only at midday (12:00). Taking into account the antioxidative characteristics of melatonin, one can suppose that maximum pineal antioxidative levels during the night might be due to maximum concentrations of nocturnal melatonin. The significant increase in peroxide concentration and the decrease in antioxidants after castration would partly explain the physiologic status of the elderly with decreased melatonin production and increased oxidative processes.

Animals↗
PubMed1993

Effect of vitamin C administration on the ratio between the pro- and antioxidative factors.

Much evidence gathered in the last years involve the free radicals (FR) in the mechanisms of initiation, development of neoplastic transformations in vivo and in vitro, as well as in the activity of specific oncogenes. Most of it comes from the fact that the agents that remove the FR or interfere in the chain of events induced by FR can inhibit the neoplastic process both at cellular and molecular level. The antioxidant and free-radical scavenging activities of vitamin C have been intensely investigated, vitamin C being considered the most important antioxidant protective agent in the plasma. Our study is focused on the changes in lipid peroxides (MDA), free SH groups and the total antioxidative capacity in the plasma of 22 patients with differentiated thyroid cancer operated and treated with 131I, and then given 1 g vitamin C/day along one month. Blood samples were collected before 131I and then 4 days following 131I administration, and after 1 month of vitamin C administration per os. The following results were noted: (1) an increase of MDA concentration after 131I; (2) a decrease in the MDA level after one month of vitamin C administration; (3) an increase in the concentration of free SH groups after 131I; (4) a decrease in the level of free SH after vitamin C, and (5) a non-significant decrease in TAC after 131I and vitamin C. The results confirm the change in the balance between the oxidative and antioxidative factors under the effect of ionizing radiations and suggest the involvement of vitamin C as a protective and/or potentiating factor for the other antioxidative systems.

Adult↗
PubMed1993

Oxidative and antioxidative factors in the serum of thyroid cancer patients treated with 131I.

The variation of some parameters involved in maintaining the balance between pro- and anti-oxidative factors was followed-up in a group of patients thyroidectomized for folliculo-papillary, papillary and follicular cancer, before and after 5 days following the 131I administration. Radiotherapy led to the intensification of lipid peroxidation expressed by a significant increase in the malondialdehyde values. Among the parameters involved in the antioxidative process we noted an increase in both SH nonprotein groups and ceruloplasmin concentration. The total antioxidative capacity lowered significantly following irradiation, whereas uric acid remained unaltered.

Adult↗
PubMed1992

The negative impact of oxidative stress in chronic cardiac failure and coronary heart disease calls for a new pathophysiologic and therapeutic approach.

Oxidative stress, when associated with ECG aspects of "coronary disease", indicates an accelerated course of atherosclerosis in the onset phase (by cellular involvement, migration, proliferation, etc.) and an additional thrombogenic risk in the "ischemic disease" phase, when associated with chronic cardiac failure, it indicates a progressive form with "replacement fibrosis". The therapy that reduces the oxidative stress can slow down the physiopathologic process, and clinically improves the patients' condition and prognosis.

Adult↗
PubMed1991

Melatonin involvement in oxidative processes.

The fact that the pineal gland, by its melatonin (MT) production, responds to environmental light variations (the day-night cycle), being also a modulator of the body adaptation to these conditions, may lead to the assumption of its involvement in the body oxidative processes. The redox capacity of melatonin was followed-up in vitro by the chemiluminescence phenomenon. The system generating chemiluminescence as well as free radicals was made up of luminol and H2O2. Incubation of melatonin in doses of 0.08-0.5 microM/ml with the generating system showed that in doses under 0.25 microM/ml melatonin has a pro-oxidative effect while in doses above this value it has an antioxidative effect. The diagram of the results shows the answer specific to a modulator. The study of the correlation between the dose of melatonin with highest pro-oxidative properties and the various peroxide concentrations in the generating system showed that melatonin gets antioxidative properties with the increase in peroxide concentrations (less than 8 mM/ml). In the presence of a hypothalamic homogenate, which is a stimulant of the chemiluminescence-generating system (PXI = 16), melatonin has a dose-dependent antioxidative effect. Similar results were also obtained by adding tryptophan--a free radicals acceptor (PXI = 0.1) and the substrate in melatonin synthesis to the reaction medium. Melatonin in low concentrations (greater than 0.1 microM/ml) has an antioxidative effect while in higher doses it has a dose-dependent pro-oxidative effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1976

Endogenous biochemical factors affecting the efficiency of some radioprotective or radiosensitizing drugs: sulfhydryl groups and lipid peroxides.

The changes in the amounts of blood and tissular sulfhydryl groups and lipid peroxides were investigated in lethally gamma-irradiated rats treated with cystamine, AET (radioprotectors) or alpha-methyl-dopa (a radiosensitizer). The results of experiments revealed the following findings: 1. The ionizing radiation generally causes increases in the levels of tissular sulfhydryl groups and lipid peroxides (excepting the hepatic levels of these compounds). 2. AET and, especially, cystamine are able to reverse the radiation-induced changes in the tissular amounts of sulfhydryl groups and lipid peroxides; there are close relationships between this effect (including its intensity and extension) and the radioprotective action of these drugs. 3. In spite of its radiosensitizing action, alpha-methyl-dopa induces approximately similar changes in the tissular amounts of sulfhydryl groups and lipid peroxides, suggesting that biochemical processes other than an excessive yield of free radicals are also involved in radiosensitivity.

Animals↗
PubMedDate not supplied

Fibrinogen interaction with activated polymorphonuclear leukocytes studied by chemiluminescence.

Fibrinogen (FB) is an acute phase protein. It is recognized as an independent risk factor in the plasma of patients with coronary heart disease (CHD). The plasma FB level is also significantly increased in inflammation and neoplasms. We performed an in vitro study showing that the chemiluminescence (CL) emission produced by zymosan-activated polymorphonuclear leukocytes (PMNL) was directly related to the concentration of FB, fibrinopeptide A or FB-degradation products (FDP). Fibrin inhibited CL emission. Our results emphasized the role of FB as an independent risk factor in CHD but related to the level of activated polymorphonuclear leukocytes in the plasma. Activated PMNL may contribute to an elevated plasma level of FDP as a consequence of enhanced enzyme-dependent degradation of FB. Our results indicate that the role of FB as independent risk factor in CHD depends on the level of activated polymorphonuclear leukocytes in the plasma.

Adult↗