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Biomedical subjects

R Iliescu

Publications and source records attributed to R Iliescu.

At least 19 recordsLinked to original sources
PubMed1985

Some physico-chemical and biological properties of egg-Sendai virus with altered haemagglutinin-neuraminidase protein.

Some physico-chemical and biological properties of egg-cultivated Sendai (egg-Sendai) virus particles with altered haemagglutinin-neuraminidase (HN) protein were studied. These particles were obtained accidentally from purified egg-Sendai virus stored at +4 degrees C. Egg-Sendai with altered HN protein was not infectious for cultured cells, but could still infect embryonated eggs. Though egg-Sendai virus with altered HN protein and glycoproteins had no haemagglutination activity, it unexpectedly possessed a relatively high neuraminidase (NA) activity representing about 70% of the activity of normal particles. Since polyacrylamide gel and rocket immunoelectrophoresis indicated that the altered particles contained only F protein, possibly the native HN was converted into a molecule of the same molecular mass as F protein.

Antigens, Viral↗
PubMed1985

Effect of some anthracycline antibiotics on the neuraminidase activity of Sendai virus and its isolated glycoproteins.

Anthracycline antibiotics violamycin BI (VBI) and adriamycin (Adr) strongly inhibited the neuraminidase (NA) activity of Sendai virus and of its isolated glycoproteins, occurring either in solution or associated in liposome-like particles. NA did not exhibit the classical Michaelis-Menten kinetics: the plot of reaction velocity versus substrate concentration was sigmoidal, while Hill's plotting indicated that the enzyme has at least two binding sites for the substrate. The reaction kinetics obtained suggested that Sendai virus NA acts as an allosteric enzyme, when its material support, the HN is located on the virus surface. The inhibitory effect of the anthracycline antibiotics in question on the NA activity seemed to be similar to that of negative effectors.

Allosteric Site↗
PubMedDate not supplied

[The detection of human papillomaviruses in histological preparations by using dot-blot hybridization].

The 56 tissue samples were obtained from female patients with anogenital tumors, benign or malign, subsequently confirmed through pathomorphological analysis. The investigations were aimed at the discovering of HPV presence using hybridization techniques with biotinylated molecular probes and monitorisation through enzymatic reaction. The presence of ADN types 11, 16 and 18 was detected on about 52% of all the cases; the ADN HPV incidence was 57% among the patients with a neoplasm and/or cervix uteri papillomatosis diagnosis.

Adult↗
PubMedDate not supplied

[Demonstration of viral proteins by silver staining].

Investigations were conducted to establish the optimal conditions for silver staining of polypeptides separated by polyacryle-amide gel electrophoresis. The thickness of the gel layer was of 1.5 mm. The experiments showed that the modified Hankeshover and Dernick's technique (4) (replacement of the fixative for the electrophoretically separated polypeptides and extension of the bleaching by Farmer's reagent time) had the best sensitivity and reproducibility. This technique can be performed also on polyacryle-amide gel preparations already stained by the Coomassie Brilliant Blue method. To check the efficiency of this silver staining technique, the authors used it to detect the Sendai virus and B hepatitis virus surface antigen polypeptides.

Electrophoresis, Polyacrylamide Gel↗
PubMedDate not supplied

[The protector effect of ribosomal preparations against experimental influenza infection in mice].

A study was conducted on the protective effect of some ribosomal preparations, isolated from chorionic-allantoic membranes of chicken embryos, infected or not with parainfluenza (Sendai) or influenza (AoPR8) virus, in mice experimentally inoculated with influenza virus strain AoPR8 adapted to the mouse. Results showed that the tested preparation, containing ribosomes and polysomes isolated from chorio-allantoic membranes of Sendai virus inoculated chicken embryos, ensure the mice complete protection against AoPR8 virus, if administrated before the control infection.

Allantois↗
PubMedDate not supplied

Cationic anticancer drugs and their modes of action.

This report focuses on two groups of cationic cancerostatics, anthracycline antibiotics and 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone (ambazone), lining up biophysical and biochemical effects on the level of membranes and membrane constituents. The interaction of both drugs with multilamellar liposomes consisting of phosphatidylcholine used as a simple model membrane system could be ensured by means of steady state and nanosecond time-resolved fluorometric investigations. The biochemical effect on membranes is underlined by the inhibition of the neuraminidase activity of the Sendai virus, modification of the CAMP phosphodiesterase activity of leukemia L 1210 cells of mice and reduction of the lymphocyte blast transformation.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

[Research conducted at the Stefan S. Nicolau Institute of Virology of Bucharest in the area of nucleic acids and genetic engineering].

A brief review is done of some of the most important studies realised by the "Stefan S. Nicolau" Institute researchers in the field of nucleic acids. It is worth mentioning among these the investigations about interactions between nucleic acids and some biologically active substances, the recombinant DNA, as well as the most recent works on DNA-DNA hybridization in the avidine-biotine system.

Academies and Institutes↗
PubMedDate not supplied

[Study of the encapsulation and transport of several proteins to different organs by means of liposomal type particles of viral origin].

Liposomal particles may be more efficiently incorporated by cells through mechanisms still incompletely elucidated. This property allowed to use them as a vehicle for macromolecules. Research was conducted to obtain liposomal type particles of viral origin charged with various proteins (bovine serum albumin, ovalbumin, ribosomes, human 125I-immunoglobulin G) and to establish the distribution of proteins encapsulated in viral envelopes among various organs after inoculation to laboratory animals.

Animals↗
PubMedDate not supplied

Research in the field of nucleic acids performed in the "Stefan S. Nicolau" Institute of Virology.

A review is made of the research in the field of nucleic acids performed in the "Stefan S. Nicolau" Institute of Virology. The results obtained as regards the infectivity of viral nucleic acids, the oncogenic capacity of nucleic acids extracted from tumors, the isolation, characterization, physicochemical and biological activity of viral and cellular nucleic acids, as well as some achievements in recombinant DNA technology, are briefly presented.

Academies and Institutes↗
PubMedDate not supplied

Investigations in the field of recombinant DNA technology performed in the "Stefan S. Nicolau" Institute of Virology.

A brief review is provided of the investigations in the field of recombinant DNA technology started in 1979 in the Central Laboratory for Nucleic Acids within the "Stefan S. Nicolau" Institute of Virology. The research efforts have been focused on the following main objectives: optimization of vector extraction, isolation and purification of restriction enzymes and of DNA ligase T4, transformation and transfection experiments, construction of recombinant DNA.

Academies and Institutes↗
PubMedDate not supplied

Investigation of the effect of cellular and viral nucleic acids on certain virus infections. Note 2. Effect of nucleic acids on virus multiplication in cell cultures.

Treatment of cell cultures with different natural nucleic acids prior to inoculation of herpes simplex virus type 1 led in certain cases to an obvious reduction in infectant titer. The reduction was maximum at a dose of 50 micrograms nucleic acid/culture tube and it was not dependent on the nature of the nucleic acid preparation. The antiviral effect of nucleic acids was enhanced by complexation with intercalation agents such as ethidium bromide or violamycin BI. No detectable amounts of interferon could be made evident in cell cultures treated with chromosomal DNA under conditions leading to a reduction by 1.75 log in infectant titer.

Aminoglycosides↗