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PubMed1991

[Effect of ploidy and the status of the MAT locus in Saccharomyces cerevisiae yeast cells on the mitotic stability of episomal plasmids and the level of expression of the HBsAg gene of hepatitis B virus].

The frequency of the YEp13, pEF91, YEp13 + HBs, pNMVG3954 plasmids' elimination in a series of isogenic strains n. 2n and 3n was studied. Plasmid stability and the level of expression of the gene of hepatitis B surface antigen (HBsAg) increased in polyploid transformants as a result of increase in plasmid copy number. Heterozygotes MATa/MAT differed from the homozygotes in higher stability of YEp13, pEF91, and YEp13 + HBs plasmids having the same quantity of the HBsAg antigen. The appearance of negative properties--destabilization of episomal plasmids or decrease in synthesis of heterologous protein have been discovered in certain diploid cell. These results point to limitations in constructing a polyploid producer on the basis of the similar type of genome.

Chromosome Mapping↗
PubMed1991

[Changes in the amount of 3H-thymidine label in hepatocytes of different ploidies in rat ontogeny after a single administration of the isotope].

Change of 3H-thymidine quantity in mono- and binuclear rat hepatocytes of different ploidy was investigated during the first 6 weeks after a single injection of isotope to newborn rats. Rates of cell transitions (arbitrary number of cells in the time unit) from one ploidy class to another, and coefficients of the reducing of hepatocyte proliferative activity with increasing the hepatocyte ploidy were calculated on the basis of ideas about the process of autoradiographic label "diluting" in the course of the postnatal development as a result of polyploidization and ordinary mitotic divisions of hepatocytes. The calculated values are close to values of parameters, which were calculated with assistance of the model, which describes the process of polyploidization in the liver, on the basis of data on the change in the arbitrary number of different ploidy hepatocytes.

Animals↗
PubMed1991

[The possible cytophotometry of nucleolar proteins. The prospects for research on the status of the nucleolus apparatus].

Possibility of cytophotometry application was established for the acid nucleolar proteins reacting with silver nitrate. The increase in transcription in the Purkinje neurons results in the expansion of the Ag-proteins areas, whereas their amount may be not increased. The amount and area of the Ag-proteins double in hepatocytes through polyploidization, but the number of nucleoli does not correspond to the gene dosage. This lack of correspondence was also revealed in micronucleoli. The number of nucleoli is not similar in the nuclei of some binuclear hepatocytes, and this disproportionality increases through polyploidization.

Animals↗
PubMed1991

Molecular biology of vascular hypertrophy.

In chronic models of hypertension such as the spontaneously hypertensive rat (SHR), thickening of the media of large arteries occurs mainly through smooth muscle cell (SMC) hypertrophy accompanied by DNA replication resulting in large polyploid cells. In resistance vessels of SHR, medial hypertrophy occurs through a hyperplastic response. It has been suggested that this hyperplasia is due to mitogens such as platelet-derived growth factor (PDGF), while the hypertrophied polyploid cells occur from stimulation by angiotensin II from within the vessel wall. Angiotensin II activates many of the same cellular pathways as PDGF, including stimulation of phospholipase C, mobilization of intracellular calcium and activation of Na+/H+ exchange. Both induce transient increases in the proto-oncogenes c-fos and c-myc. However, a possible explanation for the difference in SMC response may be involvement of an intracellular pathway stimulated by PDGF (but not by angiotensin II), such as stimulation of JE (a cytokine-like molecule), which may activate transcriptional events necessary for mitogenesis. In atherosclerosis vascular hypertrophy occurs in the form of focal intimal thickening and results from hyperplasia of diploid SMC and their greatly increased production of extracellular matrix, (particularly collagen) and the accumulation of intra- and extracellular lipid. The SMC involved in atherogenesis are phenotypically modified compared with the SMC of undiseased regions, and amongst other features have a lower volume fraction of myofilaments (Vvmyo). Associated with modulation to a low Vvmyo are increases in SMC expression of mRNA for collagens type I (alpha 1 and alpha 2) and type III (alpha 1), elastin, fibronectin, as well as massive increases in collagen protein (26- to 45-fold), glycosaminoglycans (5-fold), and lipid accumulation (7-fold).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Thrombopoietin derived from human embryonic kidney cells stimulates an increase in DNA content of murine megakaryocytes in vivo.

A thrombocytopoiesis-stimulating factor (TSF or thrombopoietin) is known to increase the size and number of mouse bone marrow megakaryocytes, to increase the proportion of megakaryocytes in endomitosis, and to increase the number of small acetylcholinesterase-positive cells. Megakaryocyte ploidy values have not previously been measured in mice treated with TSF from human embryonic kidney (HEK) cells. Therefore, in the present study C3H mice were injected with approximately 4 U of step II TSF; platelet production indices and megakaryocyte ploidy values were measured 1-5 days after treatment. For controls, other mice were injected with saline, human serum albumin (HSA), normal rabbit serum (NRS), or rabbit anti-mouse platelet serum (RAMPS). Platelet counts, platelet sizes, and percent 35S incorporation into platelets were measured using standard techniques. For measurement of megakaryocyte DNA content, bone marrow cells were collected into CATCH medium and incubated with RAMPS, followed by labeling with a saturating concentration of fluorescein-conjugated goat anti-rabbit immunoglobulin F(ab')2 fragment. After washing, the cells were resuspended in propidium iodide, and DNA content was measured by flow cytometry. When compared to suitable control values, the results showed that TSF caused a significant (p less than 0.025) increase in platelet counts of treated mice by 3 days; both TSF and RAMPS caused significant (p less than 0.0005) increases in platelet sizes and percent 35S incorporation into platelets of mice at 2 and 3 days after treatment. The most frequent polyploid DNA class of megakaryocytes from untreated C3H mice was 32N, confirming our previous observation. Both TSF and RAMPS caused significant (p less than 0.0005) increases in the average polyploid megakaryocyte DNA content, with peak values on days 2 and 3. These data show that TSF administered in vivo significantly increases DNA content of mouse bone marrow megakaryocytes.

Animals↗
PubMed1990

[Chromosomal damage in peripheral blood lymphocytes of rats in nitrosomethylurea-induced carcinogenesis].

Chromosomal damages and their dynamics in blood lymphocytes of mongrel white L10 rats treated (once) intravenously with nitrosomethyl urea (NMU) at a dose of 50 mg/kg have been analyzed. A direct correlation is revealed between carcinogenesis, chromosome aberration level in somatic cells, polyploid and hyperaneuploid cell frequency 24 hs after the NMU treatment and in the precancerous period. An increase of hyperaneuploid and polyploid cells in the organism can serve as a prognostic factor of carcinogenesis.

Aneuploidy↗
PubMed1990

Microphotometric DNA analysis in mild and moderate dysplasia of the uterine cervix: a retrospective study.

Twenty six cases of mild and moderate dysplasia of uterine cervix were retrospectively subjected to microphotometric study for nuclear DNA estimation in order to correlate their ploidy pattern with biological behaviour at initial presentation and during follow up intervals ranging from six months to six years (median-30.8 months). Of these, fourteen cases had progressed to malignancy, five persisted as dysplasia and seven had regressed to normalcy or inflammation. DNA value of these cases revealed aneuploidy in ten cases whereas polyploid and euploid DNA pattern were observed in eight cases each. Of the ten aneuploid cases eight (80.0 per cent) progressed to malignancy while two persisted as dysplasia. Of the sixteen polyploid and euploid cases, only six (37.8%) progressed to malignancy. However, five of these six cases developed aneuploidy during follow up or at the point of progression to malignancy. The findings indicate that aneuploidy in mild and moderate dysplasia cases is a reliable "high risk indicator".

Adult↗
PubMed1989

[Biological activity of hepatocellular carcinoma by analysing nuclear DNA ploidy patterns and using anti BrdU monoclonal antibody].

Cell nuclear DNA ploidy patterns were examined using cytofluorometry in hepatocellular carcinomas (HCC) induced by diethylnitrosamine (DEN) in rat and human HCC. These ploidy patterns were compared with histopathological and/or immunohistochemical studies of HCC using anti-bromodeoxyuridine monoclonal antibody. The results are summarized as follows. HCC of rats induced by DEN was occurred in 74(65.5%) of 113 rats. Intravascular invasion of the livers were seen in 31 of 74(41.9%). Metastasis was in 25 of 74(33.8%). The ploidy patterns of HCC in rats were classified into three types (types I, II and III). These ploidy patterns were closely connected with histological types of HCC in Edmondson's classification, and in order of types changing from type I to type III, 6c over polyploid cells, mitotic indices (MI) and labeling indices (LI) had a tendency to increase. In human HCC, cell nuclear DNA ploidy patterns were classified into three types similarly to experimental HCC. These ploidy patterns were closely related to histological types in Edmondson's classification. MI and 6c over polyploid cells were tendency to increase similarly to HCC of experimental rats. From the above results, measurement of DNA ploidy patterns and LI are considered a valuable parameter in examining the biological activity of HCC.

Aged↗
PubMed1989

Hereditary hepatitis in LEC rats: accumulation of abnormally high ploid nuclei.

The LEC (Long-Evans with a cinnamon-like coat color) rat is a new mutant strain with hereditary hepatitis. The rate of DNA synthesis, the relative amounts of binucleated cells, and the polyploidizations of LEC hepatocytes have been analyzed. Markedly high polyploidy, such as 32n and 64n, were detected after manifestation of hepatitis; however, no aneuploidy was detected. Bi-, tri- and tetranucleated cells whose nuclei occasionally differed in size were observed after the manifestation of hepatitis. In addition to small hepatocytes and oval cells in the periportal area of the hepatic lobule, enlarged cells with huge nuclei were also labeled with BrdU, indicating that in LEC rats suffering from hepatitis abnormal mitosis may be relevant to high polyploidization and multinucleation. Polypeptide analysis using 2D-PAGE detected the apparent lack of expression of two polypeptides, p29.5 and p30, in LEC liver cells; however, linkage analysis indicated no correlation between these peptide defects and the manifestation of hepatitis.

Aging↗
PubMed1989

[Loss of heterozygosity in the progression of tumors].

Based on the two mutation hypothesis in the development of retinoblastoma, loss of heterozygosity (LOH) of specific chromosome has been implicated in the presence of tumor suppressor gene. Studies on the LOH in different types of tumors revealed that LOH of each chromosome might play a different role in the multistep process of carcinogenesis: LOH of some chromosomes may play an etiological role in the development of some tumors, while that of other chromosomes or the same chromosome in other tumors, may play a role in the progression of tumors. LOH of chromosome 13 is an example for the former cases, and the latter cases involve LOH of chromosome 17 in colorectal carcinoma and osteosarcoma, chromosome 10 in glioblastoma, chromosome 1 in neuroblastoma and malignant melanoma, and chromosome 11 in breast carcinoma. These studies indicates that the progressive or concerted LOH could be a measure of the highly malignant or metastatic potentiality. However, it should be borne in mind that, especially in polyploid tumors, LOH also occurs as a random event following the polyploidization-segregation process.

Chromosomes, Human↗
PubMed1986

DNA ploidy patterns of minute carcinomas in the stomach.

DNA ploidy patterns of minute carcinomas in the stomach were determined by cytofluorometric measurement, using paraffin sections which had been prepared for histological examination. The examples studied were 19 minute carcinomas less than 5 mm in diameter, of which 12 were adenocarcinomas, and 7 were signet ring cell carcinomas. By measuring the fluorescence intensity of more than 30 mitotic nuclei, the DNA ploidy pattern of each tumor was determined. The control diploid DNA content was obtained by measuring the fluorescence intensity of non-cancerous mitoses in the gastric mucosa. In the present study, heteroploidy was seen in 5 carcinomas; 4 adenocarcinomas and one signet ring cell carcinoma. The remaining 14 carcinomas were composed of a diploid stem cell line. In 3 adenocarcinomas, polyploid cells were seen. The occurrence of heteroploidy in the minute cancers was similar to that found in advanced cancers, whereas polyploid cells appeared to occur less frequently in the minute cancers than in the advanced cancers.

Aged↗
PubMed1988

[Immunohistochemical studies on colorectal adenoma and carcinoma--correlation of cellular dysplasia and intracellular CEA distribution, lectin-binding sites and quantities of nuclear Feulgen DNA content].

Intracellular distribution of CEA, lectin binding sites including PNA, DBA and UEA-1, and quantity of nuclear DNA content were examined in 54 adenomas and 29 carcinomas of the colorectum. CEA was found in 40% and 60% of adenomas with mild and moderate dysplasia, and all carcinomas. In particular CEA which was diffusely distributed in the cytoplasm was found in 9% and 26% of adenomas with mild and moderate dysplasia, and in 79% of carcinomas. Both PNA and DBA were shown to have different binding sites in non-tumorous mucosa, adenoma and carcinoma. However, no difference was found in the binding sites of adenomas with different grades of dysplasia. Whereas, the binding sites of UEA-1 were demonstrated to differ with the degree of dysplasia in adenomas and also carcinomas: UEA-1 binding in the brush border was found to be 29%, 63%, and 80% in adenomas with mild and moderate dysplasia, and carcinomas respectively. Nuclear Feulgen DNA content increased in parallel with the grade of cellular dysplasia. All carcinomas exhibited polyploid cell over 4C greater than 8%. Thirty percent of adenomas with moderate dysplasia also showed the same polyploid cells as carcinomas. These results suggest that the changes of CEA distribution, binding sites of lectins and of nuclear Feulgen DNA in adenoma may indicate its malignant potential in the colorectum, and that these changes may occur before any histological malignant transformation.

Adenoma↗
PubMedDate not supplied

[Ergosterol synthesis by hybrids and strains of yeasts of the genus saccharomyces with different ploidies].

Numerous hybrid and polyploid strains of the Saccharomyces genus were obtained by hybridization. The activity of ergosterol synthesis was assayed in hybrids, several industrial races, and in haploid and diploid cultures produced from the spores of these races. The content of ergosterol was determined in 160 strains and hybrids. Ergosterol synthesis is controlled by recessive genes, and accumulation of ergosterol in the cell depends on the interaction between genes. During growth in semiindustrial conditions, triploid hybrids accumulated more biomass than diploid, and particularly haploid, strains. Polyploid hybrids valuable for food industry have been selected, according to several characteristics, from active hybrid strains. One of them, the triploid 262, is characterized by a high rate of ergosterol synthesis, good baking quality, and resistance to dehydration.

Ergosterol↗
PubMed1988

Cytogenetic effects of the addition of leukocytes and blood sera on human fibroblasts exposed to measles virus or to streptolysin-O.

Infection with measles virus and also introduction of streptolysin-O induced a significant increase in the level of cells with cytogenetic disturbances in the culture of human fibroblasts (HF). A decrease to intact condition of the number of HF with aneuploid and polyploid sets of chromosomes was observed after the introduction of non-immune autologous T-lymphocytes into the cultures. Immune homologous T-lymphocytes, unlike non-immune autologous T-lymphocytes, eliminated cells with structural disturbances of the chromosomes from the culture, but did not influence the level of aneuploid and polyploid cells. The ability of immune T-lymphocytes to exert antimutagenic effect can obviously be explained by their cytolytic action on virus-infected cells. As for non-immune autologous T-lymphocytes, two ways are equally probable: T-lymphocytes eliminate HF with virus antigens on their surface, or T-lymphocytes determine and destroy fibroblasts with changed cell surface developing as a result of cytogenetic disturbances induced by infectious factors. Specificity of the cytolytic reaction of T-lymphocytes concerning cells with some types of cytogenetic disturbances has been demonstrated.

Bacterial Proteins↗
PubMed1978

[Electrophoretic analysis of substrate specificity of wheat alcohol dehydrogenases].

Electrophoresis in polyacrylamide gel slabs has been used to study the isoform composition and substrate specificity of alcohol dehydrogenases in the embryo and young seedlings of the diploid wheat Triticum monococcum L., the tetraploid T. dicoccon (Schrank) Schuebl and the hexaploid T. spelta L. Three alcohol dehydrogenases of different substrate specificity and developmental pattern were distinguished: a) the NAD-dependent alcohol dehydrogenase, catalyzing the oxidation of different primary and secondary aliphatic and aromatic alcohols, as well as certain compounds with several hydroxyl groups (tris, triethanolamin) and revealing, after electrophoresis, one major band in the diploid wheat and three bands in both polyploid wheats; b) the NADP-dependent aromatic alcohol dehydrogenase (substrate--cinnamic alcohol), revealing, after electrophoresis, one major fast moving band in the diploid wheat and two bands in polyploid wheats; c) an aromatic alcohol dehydrogenase (2-3 bands after electrophoreis) with no specificity to the cofactors (NAD or NADP).

Alcohol Oxidoreductases↗
PubMed1988

[A study of DNA ploidy patterns of gastric cancers].

The nuclear DNA fluorescence of gastric cancer cells which were obtained from endoscopic biopsies and paraffin block specimen was measured. Histograms in 142 cases could be roughly classified into four types: Type Ia, means diploid pattern without polyploid cells, type Ib, diploid pattern with polyploid cells, type II, heteroploid pattern and type III, mosaic pattern. Although these DNA patterns showed no correlation with histological types, type Ia was frequently found in early-stage cancer and type III in advanced-stage cancer. In cases without vascular invasion and in each metastasis, type Ia were significantly numerous. With regard to prognosis, the survival rate was becoming poorer in order of Ia less than Ib less than II less than III. In 41 cases out of 45 advanced-stage cancers, DNA patterns of superficial and deep portion of gastric cancer were found the same. In 5 cases, DNA patterns of cancer cells in metastatic lymph nodes were coincident with DNA patterns in gastric cancers. These results suggested that the measurement of nuclear DNA pattern may provides a biological activity of gastric cancer cells and preoperative examination of endoscopic biopsy specimens from this aspect is also clinically important.

Adenocarcinoma↗
PubMed1986

[Structure of the centriolar complex in the hepatocytes of intact and regenerating mouse live].

The structure of the cellular center in polyploid hepatocytes of intact and regenerating liver of adult mice has been studied. It was shown that the structure of the centriolar complex depends on stages of the cellular cycle. No pericentriolar structures (such as satellites, appendages and others) and cytoplasmic microtubules were found in the centriolar complex within G0-period. The satellites and appendages are formed in the half of the centrioles within G1-period. The microtubules can branch off some satellites; the daughter centrioles begin to form within S-period; there are diplosomes in the cells within G2-period, some mother centrioles are surrounded with the fine fibrillar halo. It is concluded that the structure of the centriolar complex within G0-period is distinguished by that within G1-period. The structure of the centriolar complex in polyploid hepatocytes has the same feature of reorganization in certain interphase periods of the cell cycle as in diploid cells of some cultured cells and the thyroid epithelium.

Animals↗
PubMed1987

[Levels of DNA and sex chromatin bodies in the myocyte nuclei of different sections of the human heart].

Nuclei of ventricular, atrial and atrioventricular node myocytes of normal and hypertrophied human heart were studied on squash preparations and on 12 micron sections after the Feulgen staining. The cytophotometric DNA measurements have shown a distinction in the degree of polyploidization of nuclei in different heart compartments. In contrast to ventricular and atrial myocardia, in which polyploid nuclei predominate, the conduction system myocytes contain 77-88% of diploid nuclei. A correlation between DNA content and the number of sex chromatin bodies was observed for myocyte nuclei from all the compartments under investigation.

Atrioventricular Node↗