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PubMed1989

[A case of pulmonary carcinoma presenting flow cytometrical heterogeneity of the nuclear DNA content between its primary focus and the metastatic foci].

We have experienced case involving a 63-year-old patient with a pulmonary carcinoma, who was given an enterectomy following a lobectomy, due to minimal intestinal metastasis. In this case, using flow cytometry, the cancer cell nuclear DNA content was analyzed for the primary tumor focus, the mediastinal lymph node metastatic focus, and the small intestinal metastatic focus. For the primary focus, a cancer cellular population of polyploidy with 2 ploidies of DNA content was observed, while for both the metastatic foci, only a single cancer cellular population was observed, indicating the heterogeneity of the nuclear DNA content between the primary focus and metastatic foci. These 2 metastatic foci had DNA contents completely corresponding to that for a ploidy with a high DNA content in the primary focus, suggesting a metastasis of only the above population from the primary focus. The present case apparently formed metastatic foci in other organs than the lungs but only by cancer cells more susceptible to metastasis among the cancer cells found in the primary focus.

Aneuploidy↗
PubMed1987

[Polyploidization dynamics of tertiary trophoblast giant cells in the rat placenta].

Polyploidization peculiarities of tertiary giant trophoblast cells during their active detaching from the ectoplacental cone and migrating into decidua basalis are investigated. On the 12th day of gestation, the ploidy of the majority of cell nuclei varies within 4-8c, although there are a few 16c and 32c nuclei. On the 13th and 14th days of gestation, the ploidy level of tertiary giant trophoblast cells enhances; 8c and 16c nuclei prevail, the percentage of 32c nuclei increases, 64c nuclei arising. The ploidy level of tertiary giant cell coincides with the average and/or maximum ploidy degree of precursor cell populations. The significance of polyploidy as indispensable condition of differentiation of the trophoblast cells that actively invade into maternal tissues is discussed.

Animals↗
PubMedDate not supplied

[More active synthesis of the polysaccharide, pullulan, by polyploid cultures of Pullularia pullulans].

The polyploid strains of Pullularia pullulans differ from each other and from the haploid strain in the amount of the polysaccharide pullulan liberated into the cultural broth. The highest pullulan synthesizing activity (per unit of the assimilated carbon source and the synthesized biomass) was manifested by the diploid strain of P. pullulans 1125(13) whose cells produced more pullulan (by 75%) within three days of growth than the cells of the haploid culture. The content of pullulan calculated per unit area of the cell surface increased with the level of ploidy: 1.5-1.8 times in the diploid cultures and 3.4 times in the tetraploid culture cf. the parent haploid culture. Apparently, the polyploidy of the P. pullulans culture was accompanied with mutations involved in the synthesis of the extracellular polysaccharide.

Culture Media↗
PubMed1975

[On the sex chromatin and sex chromatin-like nuclear structures in human Purkinje-cells].

INTRODUCTION: Animal experiments have shown that in the course of chromatolysis the nuclear sex chromatin of nerve cells of female mammals changes its customary location at the nucleolus and migrates to the nuclear membrane; moreover, in the nuclei of nerve cells of males there occur under similar conditions nuclear structures which resemble the sex chromatin. It was, therefore, thought of interest to see if similar findings also apply to human Purkinje-cells. MATERIAL AND METHODS: The cerebellum of 100 female and 52 male corpses of various ages was examined. Paraffin sections, 2-5 mum thick, were stained with haemalumeosin and, after hydrolysis by hydrochloric acid, with cresyl violet of Schiff's reagent (Feulgen stain). In each cerebellum 100 Purkinje-cells, whose nuclei showed a well developed nucleolus and an obvious Barr body, were studied. In the cerebellum of 29 female corpses the cells examined showed a marked cytoplasmic chromatolysis; in the Purkinje-cells of the remaining 71 female, and of all the male corpses the stage of chromatolysis was classified according to the degree of dissolution of the Nissl bodies as "feeble", "marked", or as the stage of restitution, characterized by nuclear caps. RESULTS: The sex chromatin was seen as a, mainly, round and compact chromocenter with a maximal diameter of 0.6--1.6 mum. The larger Barr bodies were seen more frequently, if chromatolysis in the corresponding cells was marked. With increasing chromatolysis the Barr body, which usually occupies a perinucleolar location, tended to be found more often at or near the nuclear membrane. In the cerebellum of the males 17.4% of the Purkinje cells studied showed heteropyknotic nuclear structures which could not always be distinguished in size or in appearance from a sex chromatin. They occupied predominantly a perinuclear position. but with increasing chromatolysis they too were seen more frequently in a location which tended to be intermediary or near the nuclear membrane. Not infrequently the nuclei simultaneously presented a granular hyperchromatosis. DISCUSSION: The change in the location of the sex chromatin in the nucleus is considered to be associated with compensatory processes following chromatolysis. These in turn are accompanied by an intranuclear current of materials, such as RNA, towards the periphery of the nucleus, or by changed electric potentials which develop in the affected cells. The variations in size of the Barr body should be attributed to a variable condensation of the corresponding X-chromosome, rather than to polyploidy of the nerve cell nuclei. The sex chromatin-like chromocenters, which are seen in "male" Purkinje-cells in the course of chromatolysis, could be attributed to certain chromosomal segments which have a tendency to heterochromasia...

Cell Nucleolus↗
PubMed1975

[Morphological and cytofluorometric study of the giant cells of the trophoblast of the common vole].

The primary and secondary giant cells of trophoblast in placenta Microtus arvalis were studied. The giant polyploid nuclei are formed in result of series of successively proceeding endomitotic polyploidization of chromosomes. Two stages of endomitosis are described: endointerphase with the uniform net of thin chromatin threads and the stage when small round or rod-shaped paired chromosomes gather mostly under the nuclear membrane. Great number of round, oval, and complex-shaped nucleoli may be seen in nuclei during both stages of endomitosis, the number growing during polyploidization. The morphology of the chromosome-nucleolar apparatus involves peculiarities of the polyploidization mechanism in placenta Microtus arvalis trophoblast. Endomitosis occurs both in low and high-polyploid nuclei. Cytofluorometric determination of the DNA amount in nuclei polyploid nature. The degree of polyploidy of the trophoblast giant cells nuclei during terminal differentiation of placenta corresponds to 128c-512c, and some nuclei contain the DNA amount corresponding to 1024 and 2048 chromosomal sets. The cause of origin of the polyploid cells in trophoblast of rodents placenta is discussed.

Animals↗
PubMed1979

Cytologic and genetic features of mammalian cultured cells adapted to hypertonic medium.

The response to changes in the osmotic pressure and the capability to adapt to raised tonicity of culture medium, obtained by increasing the NaCl molarity (0.137M), varies among different Mammalian cell lines. Cells cultured in permissive hypertonic medium become resistant to more drastic hypertonic solutions, which are incompatible with cell survival, in the absence of any pretreatment. When cells grown in hypertonic medium are fed again with normal medium, they do not maintain their greater resistance acquired by adaptation; this points to a reversible physiological process rather than to a stable regulatory change at a genetic level. Cells of the EUE line (human embryonic epithelium), grown in medium containing a doubled NaCl concentration (0.274M), show a growth rate slower than cells cultured in a isotonic medium, whereas the plating efficiency is apparently unaffected. The chromosome number distribution in EUE cells cultured in hypertonic medium shows a significant increase in the frequency of cells with a double chromosomal set (20% in treated cells versus 1.5% in control cells). The induction of polyploidy in hypertonic media can be a useful tool in experiments of genetic analysis based on chromosome segregation via tetraploidy. Furthermore the osmotic adaptation of cells in vitro can provide a useful selective system for the isolation of cellular hybrids.

Adaptation, Biological↗
PubMed1983

Genetics and evolution of multilocus isozymes in hexaploid wheat.

Aneuploid genetic studies of isozyme variation in cv Chinese Spring have disclosed that numerous enzymes of hexaploid wheat exist in multiple molecular forms as a direct consequence of polyploidy. Sixty-nine isozyme structural genes have been identified to date. Two of these belong to a duplicate set and at least 54 to triplicate sets of paralogous genes that are located one each in related chromosomes in different genomes. Each of these gene sets encodes either two or three isozymes. The role of regional gene duplication in the production of multilocus isozymes in hexaploid wheat is as yet poorly understood, although a considerable amount of indirect evidence suggests that a large number of isozymes are encoded by genes that were produced by ancient regional gene duplication events in a genome ancestral to the genomes now present in the species. A full assessment of the role of regional gene duplication in the production of hexaploid wheat isozymes must await further studies. The isozyme structural gene locations thus far determined indicate that the gene synteny relationships that existed in the ancestral wheat genome are in large part conserved in each of the three genomes of cv Chinese Spring and that the genetic content of most individual chromosome arms has also been in large part conserved.

Biological Evolution↗
PubMedDate not supplied

[Double-mutation hypothesis of carcinogenesis].

Recent data on cell oncogenes, recessive mutations of certain genes which result in malignization, protective effects of polyploidy are discussed from the standpoint of mutation hypothesis of carcinogenesis. In general, these data and models confirm main conclusions of the two-step hypothesis of carcinogenesis which was put forward by V. A. Strunnikov in 1958.

Alleles↗
PubMed1983

Malignant histiocytosis. The diagnosis based on chromosomal, immunologic and histiopathologic analysis.

A 38-year-old female suffered for several months from persistent fever without signs of infectious or immunologic disease. 57Co-bleomycin scintigraphy revealed abnormal concentration in the liver. Following a diagnostic laparotomy, the patient died from abdominal haemorrhage. Malignant cell infiltration was demonstrated in a biopsy from the liver. Histiocytic cells were demonstrated in a bone marrow smear obtained shortly before death. Investigation of cultured lymphocytes obtained from the patient the day before she died showed deficiency of T-lymphocytes. Investigations of chromosomes delineated several clones with polyploidi. The diagnosis of malignant histiocytosis was based on erythrophagocytosis, and immunologic and chromosomal aberrations. If malignant histiocytosis is the primary disease, a terminal stage of different diseases or a sign of complication secondary to immuno incompetence (e.g. virus infection) is an open question.

Adult↗
PubMedDate not supplied

[Chromosomal control of early mammalian development].

A review of recent studies on mammalian embryos, mostly mice, with chromosomal aberrations. Morphological, biochemical and cytological studies on mice with polyploidy, aneuploidy and some structural aberrations are discussed. Some types of chromosomal aberrations, especially monosomy for individual chromosomes (2, 5, 7, or 17), are already evident during early cleavage and are inevitably lethal by the morula stage. A direct relationship exists between the duration of survival and chromosome aberrations (trisomy and monosomy) for every chromosome. Differential gene activity of the mouse autosomes becomes evident already at the very early developmental stages. Some feasible causes of the early death of embryos with autosomal monosomy are discussed and a hypothetical mechanism for the activation of homologous autosomes at the early developmental stages is proposed. Perspectives of future studies in cytogenetics of mammalian development are outlined.

Aneuploidy↗
PubMed1981

Cytogenic analysis of preimplantation blastocysts from prepuberal gilts treated with gonadotropins.

Metaphase chromosomes were examined in 10-day-old embryos collected from prepuberal gilts that had been induced to ovulate, using a combination of 200 IU of human chorionic gonadotropin (HCG) and 400, 600, or 800 IU of pregnant mare serum gonadotropin (PMSG) followed 72 hours later by 500 IU of HCG. A repeatable, reliable method was developed for the processing of early porcine embryos in the hatched spherical blastocyst stage for cytogenetic analysis. Of 170 embryos recovered and processed from 21 gilts, 169 yielded analyzable metaphase cells for determination of somatic cell chromosome number for an overall success rate of 99.4%. All embryos were diploid (2n = 38) in chromosomal constitution, and although isolated tetraploid (4n = 76) and octaploid (8n = 152) cells were found, true triploid or other polyploid embryos were not present. The absence of these aberrations indicated that at the dosage levels tested, the hormone PMSG did not cause an increase in occurrence of polyploidy in porcine blastocysts present at day 10 of gestation. Analyses showed no significant (P less than 0.05) increase in numbers of corpora lutea or embryos at day 10 of gestation in gilts treated with these PMSG dosage levels.

Animals↗
PubMed1980

Diagnosis of a triploid fetus at genetic amniocentesis.

Nearly 20% of spontaneously aborted fetuses with chromosomal errors have been shown to have a triploid karyotype. Such a fetus is rarely encountered during the course of an amniocentesis at midtrimester. Because amniotic fluid cell polyploidy is an occasional finding among normal fetuses at midtrimester, the following report illustrates the importance of gathering corroborative evidence of an affected fetus before arriving at a prenatal diagnosis.

Adult↗
PubMed1995

Detection of triploidy in fish using the cytokinesis-blocked method for erythrocyte and hepatic cells.

The use of two cytochalasin-blocked methods with erythrocyte and hepatic cells was developed to identify spontaneous and/or induced triploid fish by observing the presence of trinucleated cells. Spontaneous triploids were found in two specimens out of fifteen commercial rainbow trout from a hatchery at 2 years of age. Some rare spontaneous triploid (3n) trinucleated cells were also found in the other thirteen diploid (2n) trout specimens under investigation. The use of this novel technique in a study of the triploidy in vitro, allows evaluation of the polyploid specimens under field and laboratory experimental conditions. The potential contribution of binucleated hepatic and erythrocyte techniques in fish to the assessment of polyploidy is discussed.

Animals↗
PubMed1994

The connection between the nuclei of binucleated hepatocytes: an ultrastructural study.

Hepatocytes commonly have double nuclei and polyploidy. Both increase with age. The relationship of the double nuclei to each other has never been investigated at the ultrastructural level. Using a newly developed extraction and embedding technique we observed that the two nuclei were often linked by connecting DNA strands which span the gap between the two nuclei. The DNA nature of these filaments was determined by digestion with DNase. Artifactual intermolecular disulfide bonds were prevented by the employment of iodoacetamide in the extracting medium. It was further shown that partially fused and/or separated nuclei were observed by phase microscopy of living cultures as well as in fixed liver tissue. The results may indicate that one way in which binucleation occurs is through nuclear separation when the nucleus contains multiples of DNA (polyploid).

Animals↗
PubMed1995

Factors regulating megakaryocyte progenitor commitment to polyploidization.

Recognizable megakaryocytes are polyploid cells generated by a clonogenic, diploid progenitor, termed CFU-MKC (colony forming unit, megakaryocyte). In order to quantify polyploidization, ploidy histograms of megakaryocytes determined by microphotometric or flow cytometric measurements of megakaryocyte DNA have generally been used. However these techniques provide no information on the rate of commitment of CFU-MKC to polyploidy. Using a technique of clonal analysis determining the distributions of the number of doublings (NbD) undergone by CFU-MKC before committing to polyploidization, the polyploidization probability of CFU-MKC could be derived. This probability was found to be a constant independent from CFU-MKC mitotic history, since NbD distributions are exponential functions characterized by a constant rate of decay per doubling. By studying the effects of growth factors on polyploidization probability, it was also shown that: (1) this parameter is negatively regulated by growth factors contained in poke-weed or WEHI conditioned media, as well as by erythropoietin; (2) commitment to polyploidization does not require prior CFU-MKC division; (3) bipotent erythroid-megakaryocyte progenitors have a lower polyploidization probability than CFU-MKC; (4) determination of polyploidization probability reflects the activity of growth factors with greater accuracy than megakaryocyte colony count.

Acetylcholinesterase↗
PubMed1995

Behavioural differences and cytogenetic analysis of a transformed cellular population derived from a Vero cell line.

Arising from a Vero cell line, an altered population was spontaneously obtained, which grew in multiple layers. Cytogenetic analyses revealed a higher polyploidy index (19%) than occurred in the initial population (5%). A modal chromosome number of 56 was found for the altered population, while the initial cell culture had only 54 chromosomes. Karyotypic studies showed that the extranumerary chromosomes were homologues of the 8th and the 27th pairs. The altered population probably resulted from a transformation of the initial line, and their transformed phenotypes may have been associated with the cytological differences.

Animals↗
PubMed1994

Toxicity studies on Reactive Blue-2 leached from affinity material exposed to extreme chemical conditions.

Toxicity effects related to leached ligands from affinity sorbents that can contaminate biological preparations were investigated in the particular case of immobilized Reactive Blue-2. Initially, identification of the real chemical structure of leached dye has been done by HPLC after incubation in extreme conditions. Toxicity investigations in vitro involving several well known tests showed no toxic effects within the studied range of dye concentration. Cell cultures behaved normally when the adhesion phase was successful; polyploidy induction in human cells by the native dye and its derivatives identified as possible leached material was very similar to standard cultures. Genotoxicity studies did not evidence any toxic effect in E. Coli cultures of dyes themselves or of the same dyes after metabolic activation.

Cell Adhesion↗
PubMed1995

Factors regulating megakaryocyte progenitor commitment to polyploidization.

Recognizable megakaryocytes are polyploid cells generated by a clonogenic, diploid progenitor, termed CFU-MKC (colony forming unit, megakaryocyte). In order to quantify polyploidization, ploidy histograms of megakaryocytes determined by microphotometric or flow cytometric measurements of megakaryocyte DNA have generally been used. However these techniques provide no information on the rate of commitment of CFU-MKC to polyploidy. Using a technique of clonal analysis determining the distributions of the number of doublings (NbD) undergone by CFU-MKC before committing to polyploidization, the polyploidization probability of CFU-MKC could be derived. This probability was found to be a constant independent from CFU-MKC mitotic history, since NbD distributions are exponential functions characterized by a constant rate of decay per doubling. By studying the effects of growth factors on polyploidization probability, it was also shown that: (1) this parameter is negatively regulated by growth factors contained in poke-weed or WEHI conditioned media, as well as by erythropoietin; (2) commitment to polyploidization does not require prior CFU-MKC division; (3) bipotent erythroid-megakaryocyte progenitors have a lower polyploidization probability than CFU-MKC; (4) determination of polyploidization probability reflects the activity of growth factors with greater accuracy than megakaryocyte colony count.

Acetylcholinesterase↗