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Biomedical subjects

A Olinescu

Publications and source records attributed to A Olinescu.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[Nonspecific natural cytotoxicity as an active participant in the ensemble of the means of immune defense].

The organism of mammals, the most evolved animals phylogenetically possess complex mechanisms of immune defence. The effectors of these mechanisms can be grouped according to the way in which they recognize structures non self to the organism, into two large categories: (a) that attack the antigen regardless of its antigenic nature, therefore unspecific, and (b) that attacks and destroys the antigen selectively, i.e. specifically. According to the way in which and the distance at which foreign elements are recognized, the defence means act (a) by humoral mediated (at a distance through antibodies), and (b) by cellular mediation (by direct contact between the effector cells and the target). Until recently, the humoral mediated defence (formation of antigen-antibody complex, complement activation, etc.) or some forms of cell mediated defence (cytotoxicity exercised by T cytotoxic cells or K killer cells) were considered as the major, dominant elements of protection of the organism. Another defence component has recently been identified, that acts unspecifically by direct contact with the target cell and which, in contrast to what was known up to date, manifests its function even if the organism has never before come in contact with the respective aggressor (was not immune stimulated). This means of defence is not influenced by previous immunizations, being maintained at a constant level, but is influenced by a series of other factors. It is known as unspecific natural cytotoxicity, and the effector cells as natural killer (NK) cells. The NK function intervenes along the first line of defence in viral, bacterial infections, neoplasms, etc. The present paper refers to the biological role of NK cells and their possible relationship with the other components of the immune system.

Antibody Formation↗
PubMedDate not supplied

[Ontogeny of the immune response in mice. I. Presence of IgG and alpha fetoprotein in the body fluids of mice of various ages].

Alpha protein and IgG were determined by radial immunodiffusion in Swiss mice, in the amniotic fluid, milk and serum of the mice at different ages (fetus, neonates, at the age of 5, 10, 15, 20, 25, 30, 35 and 40 days and adults). The highest alpha-protein concentrations were found in the fetal serum (0.20 mg/ml) ; after birth serum levels rapidly fell and at 20 days could no longer be detected ; it was present in the amniotic fluid and milk collected within the first 24 hours after birth. In contrast, IgG was found in small concentrations in the fetal serum (0.60 mg/ml) but increased with age after birth. This immunoglobulin was present in the amniotic fluid and mothers' milk for 15 days. The significance of the results is discussed.

Age Factors↗
PubMedDate not supplied

Action of some proteic and carbohydrate components of Symphytum officinale upon normal and neoplastic cells.

The crude watery extract of Symphytum officinale and certain proteic and carbohydrate components isolated from it were studied for their effect upon the in vivo and in vitro proliferation of Ehrlich ascites cells, EL-4 cell line and of human T lymphocytes and upon the respiratory burst of human PMN granulocytes stimulated via Fc receptors. The results indicate that the crude extract and its proteic fraction stimulate the in vivo proliferation of the studied neoplastic cells and exert an antimitotic effect on human T lymphocytes in vitro stimulated with PHA. The vegetal preparations have remarkable effects on the respiratory burst of the granulocytes non-stimulated and stimulated via Fc receptors. The data underline the necessity to study thoroughly the effects of different phyto compounds through both pharmacological and immunological methods.

Animals↗
PubMedDate not supplied

The influence of some vegetable extracts on the in vitro adherence of mouse and human lymphocytes to nylon fibers.

We found that the total watery extracts obtained from roots of various plants such as Symphytum officinale, Phytolacca americana etc, precipitate human glycoproteins, agglutinate sheep red blood cells (SRBC) and stimulate lymphocyte adherence to nylon fibers. Five out of seven extracts precipitated human gammaglobulins and one of seven obviously agglutinate SRBC. If these cells were pretreated with rabbit antibodies against SRBC, all extracts agglutinated the cells at various degrees of intensity, the most active being Phytolacca americana. The adherence of mouse but not human lymphocytes to nylon fibers was stimulated by extracts of Symphytum officinale and Phytolacca americana. This process was neither stimulated nor inhibited by Mannose (Man), Galactose (Gal), Glucose (Glc), N-acethyl Galactose (GalNAc) and N-acethyl Glucose (Glc-NAc). These biological effects of the plant extracts could be the expression of a lectin-like ability to bind various sugars other than those mentioned. The results suggest the possibility of using different extracts as means to point out the presence in serum or at the cellular level of some carbohydrates influencing the cellular adhesion, phenomenon which plays an important role in the functions of hematopoietic cells.

Agglutination↗
PubMedDate not supplied

[The effect of products of plant and microbial origin on phagocytic function and on the release of oxygen free radicals by mouse peritoneal macrophages].

The effect of in vivo stimulation with an aqueous extract obtained from roots of Symphytum officinale and Cantastim on mouse peritoneal macrophages was investigated. The results obtained showed that these products initially activated the respiratory burst of the cells and later inhibited it, activating the synthesis of catalase, SOD etc. These data suggest that macrophages challenged by various ingested antigens destroy them initially through oxygen dependent mechanisms and later through enzymatic digestion in order to retain unimpaired their epitopes.

Adjuvants, Immunologic↗
PubMedDate not supplied

Evaluation of the safety of cantastim in normal humans.

CANTASTIM, a good immunomodulatory agent obtained from a highly pathogenic strain of Pseudomonas aeruginosa was inoculated during 12 weeks in 21 healthy individuals aged 18-45 years. The subjects were clinically and laboratory investigated for body weight, antibodies against DNA, collage, cardiolipin, number of blood cells, blood and urine enzymes etc. After this intensive therapy, all the studied parameters were found in normal range of values. The results are a proof that this immunomodulator is not antigenic and has not side effects.

Adjuvants, Immunologic↗
PubMedDate not supplied

DNA cell cycle analysis of K562 and Ehrlich tumor cells by flow cytometry.

Monitoring cell activation processes and cell cycle progression in cells of various ontogenetic and phylogenetic origins is one of the base challenges in cellular biology. Flow cytometric analysis by DNA histograms show the cell cycle distribution and indicate the S-phase fractions of cell populations, as well as those cells in Go/G1 and G2/M phases. Human and murine normal diploid cells, K562 tumor cells (human origin) and Ehrlich cells (murine origin) were analysed using a propidium iodide staining procedure for flow cytometry. Our preliminary results suggested that this method may be a useful tool to detect cell populations with quantitative changes in DNA content, and to estimate cell fractions.

Aneuploidy↗