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Biomedical subjects

L Dumitrescu

Publications and source records attributed to L Dumitrescu.

31 records · Page 2Linked to original sources
PubMedDate not supplied

Morphological and cytogenetical changes in HR-18 rat ascites cells after in vitro 3-[bis(2-chloroethyl)amino]-4-methylbenzoic acid (NSC-146171; IOB-82) administration.

A bifunctional alkylating agent, 3-[Bis(2-chloroethyl) amino]-4-methylbenzoic acid (NSC-146171; IOB-82) was administered in HR-18 rat ascites cell cultures (which presented 2 morphologic cellular types: A and B type cells, genetically, 2 cellular populations having 41-45 and 85-86 chromosomes and cells with high ploidy), and the morphological and cytogenetical effects were related to the compound concentration. Thus, 24 h after IOB-82 administration in small doses (3.62 X 10(-4) micron/ml), important morphological changes were observed: nuclear changes (denuded nuclei, pyknosis) and cytoplasmic alterations (breaks at the exoplasm level, followed by cytoplasmic extrusions in extracellular spaces, cytoplasmic vacuolization). In addition to these changes, other abnormalities were observed when IOB-82 was administered in large doses (3.62 X 10(-3) micron/ml), i.e., nuclear changes (nuclear residues, granulation of the nuclear material and spreading of the nuclear content into cytoplasm) and cytoplasmic alterations (cytoplasmic shades and accentuated cytoplasmic vacuolization). Generally, the large A-type cells were more affected. Twenty-four h after IOB-82 treatment (with small or large doses), the chromatid and chromosome aberrations (gaps, breaks, deletions, fragments) were also observed. These aberrations were more numerous when IOB-82 was administered in large doses. Both morphological and cytogenetical changes indicate that the effect of IOB-82 could be radiomimetic. Changes produced and their incidence appear to depend on the concentration of IOB-82 employed and the morphological type of ascites cells. These are expressed in terms of multiple abnormality production in these cells. IOB-82 treatment produced changes in chromosome numbers and especially the disappearance of polyploid cells and cell populations with 85-86 chromosomes. These results indicate a possible correlation between the increased sensitivity of HR-18 rat ascites cells and changes in ploidy.

Animals↗
PubMedDate not supplied

Morphological study of the thymus of Jensen tumor-bearing rats after tumoral, non-tumoral antigens and thiamine diphosphate administration.

The morphological changes produced in the thymus of Jensen tumor-bearing rats after specific immune stimulation (glycoprotein 8 obtained from Jensen tumor, bovine serumalbumin (BSA), tuberculoprotein, gylcoprotein 5 from normal rat blood) and after non-specific one (thiamine diphosphate (TDP)) were studied. The changes produced by associating the antigenic action and TDP were reviewed, too. Morphological investigations were preformed 24 hours and 7 days after beginning of treatments. Twenty-four hours and 7 days after specific (tuberculoprotein and BSA) or non-specific (TDP) stimulation, similar morphologic changes were observed in the thymus: vasodilatation, thymocyte agglomeration in perivascular sheaths and their intravascular migration. When TDP was associated with gylcoprotein 8 or tuberculin - PPD more pronounced morphological modifications were observed 24 hours after treatment, while associating it with glycoprotein 5 or BSA obvious changes have been produced after 7 days. Gylcoprotein 5 and 8 did not induced any modifications in the thymus structure.

Adjuvants, Immunologic↗