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At least 991 records · Page 55Linked to original sources
PubMed1977

Evidence for dosage compensation in parthenogenetic Hymenoptera.

Amounts of DNA-Feulgen staining in individual somatic nuclei and mature sperm of the parthenogenetic wasps, Habrobracon juglandis, H. serinopae, and Mormoniella vitripennis, were determined with a scanning microdensitometer. The haploid genome for both species of Habrobracon was estimated to be 0.15-0.16 X 10-(12) gDNA, corresponding to a molecular weight of roughly 10 X10(10) daltons. The haploid genome of M. vitripennis is approximately twice this value, 0.33-0.34 X 10-(12) g, or about 20X10(10) daltons. Measurements made on dividing nuclei from syncytial preblastoderm embryos of H. juglandis and M. viripennis showed that the chromosomes of impaternate males were present in the haploid number and contained the C amount of DNA; whereas nuclei from female preblastoderm embryos contained the diploid number of chromosomes and the 2C amount of DNA. However, hemocyte and brain cell nuclei from either male or female adult wasps contained 2C and 4C amounts of DNA. Both sexes also showed equivalent levels of polyploidy (8C, 16C, or 32C) in Malpighian tubule nuclei. Therefore, in these parthenogenetic species,, a mechanism must exist the compensates during later development for the initial two-fold difference in the chromatin content of somatic nuclei in haploid male and diploid female embryos. Hemocytes from impaternate Mormoniella diploid males and triploid females contain the 2C and 3C amounts of DNA, respectively Therefore dosage compensation involves an additional cycle of DNA replication only in hapoid cells, and it insures that a certain minimum quantity of DNA is received by each somatic cell.

Animals↗
PubMed1985

Maternal age-specific rates of numerical chromosome abnormalities with special reference to trisomy.

The effect of maternal age on the incidence of chromosomally normal spontaneous abortion and different categories of chromosome abnormality among all clinically recognized human pregnancies was evaluated. The results provide no evidence for a significant association of age with sex chromosome monosomy or polyploidy, but clearly demonstrate an effect of age on the frequency of trisomy and chromosomally normal spontaneous abortions. Estimated maternal age-specific rates of trisomy among all recognized pregnancies were calculated and suggest that a majority of oocytes of women aged 40 years and older may be aneuploid.

Abortion, Spontaneous↗
PubMed1986

Detection of metabolic changes in hepatocytes by quantitative cytochemistry.

Studies by means of quantitative histochemistry and cytochemistry have greatly contributed to the knowledge of metabolic changes in liver parenchymal cells. In the present paper recent work along this line is reviewed with emphasis on three topics, polyploidy as a source of metabolic heterogeneity, proteolysis in the regulation of hepatocyte cell mass and ischemic injury of hepatocytes. In all three fields, accuracy and precision of information obtained by quantitative histochemical means has been greatly enhanced by a thorough knowledge of the mechanisms of histochemical reactions obtained by fundamental work on matrix chemistry, and well-considered application of optical measuring tools and conditions of measurement. These are the principles put forward by van Duijn since the pioneer period of histochemistry and to whom this review is dedicated.

Alanine Transaminase↗
PubMed1991

Effects of bistramide A on a non-small-cell bronchial carcinoma line.

The antiproliferative effects of bistramide A, a nitrogenous dilactam polyether from Lissoclinum bistratum Sluiter (Urochordata), were studied at the level of the cell cycle in asynchronous cells of the NSCLCN6-L16 line. Bistramide A has a dual mechanism that induces blockade in the G1 phase (compatible with differentiation properties reported elsewhere) and causes polyploidy that is suggestive of inaptitude for cytokinesis. These effects confirm the results of cytomorphology studies in electron microscopy.

Acetamides↗
PubMed1989

Electron microscopic and Golgi study in a case of hemimegalencephaly.

Pathological findings in a case of hemimegalencephaly are presented. Hemispherectomy, performed because of intractable seizures, allowed an electron microscopic and Golgi study. Glial abnormalities consisted of hyperplasia of glia cells with giant astrocytes often containing several nuclei and proliferation of numerous Rosenthal fibers. Golgi stain showed many giant neurons with a perikaryon covered by perisomatic processes, and a complex dendritic tree. Glial abnormalities could be correlated with the firmness of the hemisphere and intense hypersignal on magnetic resonance imaging. Giant neurons were associated with an increase in size of the perikaryon and dendritic tree; this pattern suggests a polyploidy.

Brain↗
PubMed1985

Characterization of four human malignant glioma cell lines.

In this paper, the characterization of four human malignant glioma cell lines is described. The four lines are positive for glial fibrillary acidic protein (GFAP) in variable amounts. One of them, LN 992, is positive for S-100 protein. Myelin basic protein could not be detected in any of the four lines. The four lines had high levels of CNPase activity. The karyotype shows polyploidy for all lines, with modal numbers ranging from 80 to 120 and various numbers of marker chromosomes. Particular attention has been paid to the surface phenotype and a panel of three antiglioma monoclonal antibodies (Mabs), five antimelanoma Mabs, one anti-CALLA Mab, and two anti-HLA-DR Mabs has been used in an antibody-binding radioimmunoassay for the four cell lines. Lines LN 215 and LN 235 are positive with two antiglioma Mabs, LN 992 is negative. The four lines are positive with all five antimelanoma Mabs, except for LN 992 which ist negative with Mab D5. LN 992 and LN 215 are positive with the anti-CALLA Mab N2A12. LN 308 and LN 992 are positive with anti-HLA-DR Mab D4-22. There was no correlation between the in vitro morphology of the lines and the expression of the various biochemical or surface markers. These results stress the heterogeneity of the phenotype of human malignant glioma lines. These lines will be useful tools for further immunologic studies.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1992

Adozelesin, a potent new alkylating agent: cell-killing kinetics and cell-cycle effects.

Adozelesin (U-73975) was highly cytotoxic to V79 cells in culture and was more cytotoxic than several clinically active antitumor drugs as determined in a human tumor-cloning assay. Phase-specificity studies showed that cells in the M+early G1 phase were most resistant to adozelesin and those in the late G1 + early S phase were most sensitive. Adozelesin transiently slowed cell progression through the S phase and then blocked cells in G2. Some cells escaped the G2 block and either divided or commenced a second round of DNA synthesis (without undergoing cytokinesis) to become tetraploid. Adozelesin inhibited DNA synthesis more than it did RNA or protein synthesis. However, the dose needed for inhibition of DNA synthesis was 10-fold that required for inhibition of L1210 cell growth. The observation that cell growth was inhibited at doses that did not cause significant inhibition of DNA synthesis and that cells were ultimately capable of completing two rounds of DNA synthesis in the presence of the drug suggests that adozelesin did not exert its cytotoxicity by significant inhibition of DNA synthesis. It is likely that adozelesin alkylates DNA at specific sites, which leads to transient inhibition of DNA synthesis and subsequent G2 blockade followed by a succession of events (polyploidy and unbalanced growth) that result in cell death.

Alkylating Agents↗
PubMed1988

Bizarre leiomyoma of the prostate.

Obstruction of the urethra, caused by a prostatic tumour necessitated prostatectomy in a 49-yr-old man. Histology revealed a moderately cellular and vascular tumour with marked cellular atypia. After a follow-up for three years, the results of both the clinical investigations and prostatic needle biopsy were negative. Thus the original opinion of malignant prostatic mesenchymal tumour was revised, resulting in the diagnosis of bizarre leiomyoma. Subsequently the smooth muscle cell origin and the benign nature of the tumour were demonstrated by electron microscopy and Feulgen-cytophotometry, respectively. This is the first prostatic bizarre leiomyoma in which malignancy was excluded by demonstrating euploid polyploidy. This case also calls the attention to the need of more sophisticated methods in everyday diagnostic pathology.

Humans↗
PubMedDate not supplied

Early proliferative changes in hearts of hypertensive Goldblatt rats: an immunohistochemical and flow-cytometrical study.

Hyperplasia of myocytes in cardiac adaptation is a rare event in the mammalian cardiac muscle. Recent findings support the concept that proliferation of myocytes in the adult mammalian heart may be induced after a prolonged increase in pressure load on the myocardium. To determine whether short-term hypertension leads to hyperplasia of myocyte nuclei in the rat heart renal hypertension was produced in 12 Wistar rats. As soon as hypertension occurred, bromodeoxyuridine (BrdU) (50 mg/kg/day) was injected intraperitoneally on three subsequent days. Twelve sham-operated rats served as controls. After 3 days, the left cardiac ventricle was excised and double-staining with anti-BrdU antibody and propidium iodide was performed to determine the phase of cell-cycle of the BrdU-positive cells by flow-cytometry. Immunohistochemical double-staining with desmin, smooth muscle actin, vimentin, and BrdU was done to classify the BrdU-positive cells. Most of the BrdU-positive cells were in the G0/G1-phase of the cell-cycle, suggesting cell proliferation or DNA-repair have taken place; polyploidy was not observed. In the hypertensive group (4.62% +/- 2.36) significantly more cells incorporated BrdU than in the control group (1.46% +/- 0.96). Immunohistochemically, the majority of the BrdU-positive cells consisted of fibrocytes, smooth muscle cells, and endothelial cells. Only 0.35% +/- 0.26 of cardiac myocytes in the normotensive group showed positive BrdU-staining compared to 0.48% +/- 0.32 in the hypertensive group. This difference was statistically not significant. This study showed that early after onset of hypertension proliferation of non-myocytes, but not of myocytes occurred. DNA synthesis is limited almost completely to the interstitial cells and does not occur in any significant extent in cardiac myocytes. In conclusion, hyperplasia of cardiac myocytes is not observed at early stages of hypertension, but it may develop at a late stage of cardiac adaptation.

Actins↗
PubMed1975

Reaction of smooth muscle cells of blood vessels to an increase in functional load.

Changes in the muscle tissue of the caudal vena cava of rats and its branches after disturbance of the blood drainage were studied by the methods of isotope biochemistry, autoradiography, immunomorphology, and cytophotometry. Enlargement and polyploidy of the DNA-synthesizing muscle cells with activation of protein synthesis in them and the formation of intimal layers resembling the muscular layers were found in the main trunk of the vein which was dilated the most. Activation of DNA and protein synthesis in the less distended femoral vein was much less marked than in the main trunk. Activation of protein synthesis occurred after a delay compared with the activation of DNA synthesis but both processes were phases of development of hypertrophy of the muscle tissue of the vessel wall in response to increased functional loading.

Animals↗
PubMed1997

Regeneration processes in human myocardium after acute ischaemia--quantitative determination of DNA, cell number and collagen content.

We examined and compared 22 human hearts (6 normal hearts, 4 with hypertrophic cardiomyopathy and 12 after acute ischaemia) for their DNA and collagen content and their cell number. A positive correlation between total heart weight and DNA content was demonstrated in all hearts. The relative DNA content decreased and the rate of polyploidy increased in the infarcted and hypertrophied hearts. An aneuploid DNA content was found only in the infarcted hearts. Both hypertrophied and infarcted hearts showed a significantly higher collagen content than did the normal hearts. There was a positive correlation between collagen content and total heart weight in the hypertrophied hearts but not in the infarcted hearts. In the infarcted hearts, the increase in the relative collagen content in the left ventricle was significantly larger than that in the right ventricle. Heart cell number was higher than normal in some hearts with acute ischaemia, which was possibly a sign of compensatory regeneration of heart cells in hearts damaged by ischaemia.

Aged↗
PubMed1993

Porokeratosis large skin lesions are susceptible to skin cancer development: histological and cytological explanation for the susceptibility.

Porokeratosis (PK), an autosomal dominant inherited skin disorder, is known to develop malignant skin tumors on its skin lesions. Our recent literature survey has revealed that large PK skin lesions are frequently a precursor of malignant changes. In the study, large and small PK skin lesions were investigated in terms of histological features of the epidermis and of the cellular DNA content of epidermal cells. Large PK lesions frequently showed hypertrophic epidermis with many mitotic cells, while small lesions usually presented atrophic epidermis without such mitotic cells. Abnormal cells, like those containing hyperchromatic, large, and/or irregularly shaped nuclei, were present in the epidermis of both large and small lesions with a preponderance in the former over the latter. DNA polyploidy was seen more frequently in large PK lesions than in small ones. DNA index values were significantly higher in large lesions than in small ones. The histological features and DNA ploidy abnormalities probably reflect the higher proliferation and the greater potential for malignant changes of large PK skin lesions. Our study helps to explain the clinical evidence that large PK skin lesions are frequently a precursor of malignant skin tumors.

Adult↗
PubMed1993

Slow and ultrarapid freezing of fully grown germinal vesicle-stage mouse oocytes: optimization of survival rate outweighed by defective blastocyst formation.

PURPOSE: The cryopreservation of mature metaphase II-stage mouse oocytes is associated with decreased fertilizability, spindle damage, and increased polyploidy. Therefore, we investigated the outcome of cryopreservation of immature germinal vesicle-stage mouse oocytes. METHODS: Oocytes were punctured from Graafian follicles in primed F1 hybrid mice and were then released into maturation medium containing the meiotic inhibitor dibutyryl cyclic AMP. Both slow and ultrarapid freezing protocols with dimethyl sulfoxide, 1,2-proponediol, or a mixture of both agents were tested. We recorded morphological survival rates, in vitro maturation rates, and two-cell and blastocyst formation rates. Each group of frozen oocytes was compared with both unfrozen germinal vesicle-stage oocytes and metaphase II-stage oocytes. RESULTS: An optimal cryosurvival rate of 78% was reached after ultrarapid freezing with 3 M dimethyl sulfoxide followed by one-step dilution, but a decreased rate of two-cell formation was observed. Freezing with a combination of dimethyl sulfoxide and 1,2-propanediol did not improve this fertilization-decreasing effect. Very low cryosurvival rates after freezing with 1,2-propanediol indicated its inappropriateness for ultrarapid freezing of immature oocytes. The rates of in vitro maturation were equivalent for frozen-thawed and freshly collected germinal vesicle-stage oocytes, independent of the freezing protocol used. We report, nevertheless, as a general characteristic for both slow and ultrarapid freezing of fully grown germinal vesicle-stage oocytes, that the in vitro development up to the blastocyst stage is inhibited despite full nuclear maturation. CONCLUSION: We report that cryopreservation of immature germinal vesicle-stage oocytes is invariably associated with a low developmental capacity after fertilization. The rate of in vitro nuclear maturation did not equate with developmental competence. This in turn suggests the importance of cytoplasmic maturation for embryonic development.

Analysis of Variance↗
PubMed1992

An efficient multiple-exposure analysis of the toxicity of crisnatol, a DNA intercalator in phase II clinical trials.

To investigate the toxicity and mechanism of action of crisnatol (CRS), a new DNA intercalator currently in phase II clinical trials, we analyzed cellular and nuclear flow cytometric (FCM) parameters of murine erythroleukemic cells (MELC) exposed to a range of CRS concentrations over three exposure conditions: short-term (4 h), long-term (24 h), and short-term with recovery (4 h+/19 h-). At 0.5-1.0 microM CRS, 4 h exposure results in a reversible G2-phase block, while 24 h exposure results in greater than G2 polyploidy. At 5-10 microM CRS concentrations, cells exhibit persistent retardation of S-phase progression or irreversible G2 and/or greater than G2 blocks, depending on duration of exposure. Cells terminally blocked in G2 exhibit increased nuclear/cellular volumes and increased nuclear fluorescein isothiocyanate (protein) staining, suggestive of unbalanced growth. At 25-50 microM CRS concentrations, MELC exhibit severe membrane perturbation (loss of viability) regardless of exposure. In contrast, following similar exposures to an inactive isomer of CRS, MELC exhibit minimal cell cycle effects, suggesting that cell cycle kinetics may be a useful criterion for assessing potential efficacy. Similar analyses with different classes of chemotherapeutic agents reveal that the range of induced cellular/nuclear perturbations varies with the class of compound used. Taken together, these results suggest that drug toxicity can vary with both concentration and duration of exposure and, as such, a selective multiple-exposure FCM analysis may better represent the spectrum of drug action for drug development and pharmacodynamic studies.

Animals↗
PubMed1990

NCI-H292 as an alternative cell line for the isolation and propagation of the human paramyxoviruses.

Primary rhesus monkey kidney (MK) cells have long been the cells of choice for isolation and propagation of the human paramyxoviruses (parainfluenza 1, 2, 3, 4A, 4B, and mumps). However, problems with the supply and cost of MK cells and the presence of endogenous viruses, including herpes B virus and SV-5, necessitated a search for an alternative cell line. Continuous cell cultures of human origin (L132, A-549, HuT-292, HEK, G-293, G-401, A-498, A-704, CAKI-1, RD) and simian origin (LLC-MK2, BSC-1, MA-104, Vero) were evaluated for their capacity to support the growth of the human paramyxoviruses, as followed by cytopathic effect, hemadsorption, hemagglutination, and EIA. NCI-H292 (HuT-292) human lung mucoepidermoid carcinoma cells (ATCC # CRL-1848) proved to be the most sensitive line for cultivating all serotypes and strains of the paramyxoviruses. These cells were also shown to be a suitable substitute for MK in primary isolation of paramyxoviruses from clinical specimens. RPMI-1640 with 1.5 micrograms/ml trypsin was the preferred maintenance medium; alternatively, Eagle's MEM supplemented with 1.5 micrograms/ml trypsin and 0.1% ITS was satisfactory. NCI-H292 cells are a continuous line with excellent growth characteristics, although the genetic polyploidy of the cells may limit the number of passages of usable cells.

Animals↗
PubMed1990

Establishment and characterization of four new squamous cell carcinoma cell lines derived from oral tumors.

Four cell lines were established from squamous cell carcinomas (SCC) of the oral cavity. Cell lines AW 13516 and AW 8507 were derived from poorly differentiated SCC and epidermoid carcinoma of the tongue respectively. Cell line AW 10498 was derived from moderately differentiated SCC of the lower alveolus, and AW 9803 grew from a well-differentiated SCC of a retromolar trigone. The cultures showed typical epithelial cell morphology, numerous mitotic figures, occasional multinucleated giant cells, individual cell diskeratosis and nuclear and nucleolar abnormalities. The cell lines AW 13516 and AW 8507 were fast growers with a doubling time of 35.5 h and 31.9 h, respectively, which was independent of the initial seeding density. Cell lines AW 10498 (doubling time 52.2 h) and AW 9803 (doubling time 66 h) showed slower growth and had shorter doubling times at higher seeding densities. The presence of cytokeratins was detected in all the four cell lines by using polyclonal antikeratin antisera in indirect immunofluorescence and in Western blotting. None of the cell lines expressed major histocompatibility complex (MHC) class II antigens. MHC class I antigens were expressed by three cell lines but not by AW 9803. Flow cytometric analysis of DNA content and chromosomal studies suggested the presence of polyploidy and aneuploidy in all the four cell lines. Ultrastructural studies revealed typical epithelial cell features, such as the presence of desmosomes, tonofilaments and keratin bundles.

Carcinoma, Squamous Cell↗
PubMed1996

Expression of V-SRC and chromosome analysis of a newly established cell line from rat sarcoma induced by an avian retroviral strain.

In the newly established rat sarcoma cell line LSR-SF (SR) expression of pp60v-src was detected. Karyotype analyses revealed various chromosome aberrations during prolonged passaging of the tumor cells in vitro. Polyploidy was found to be a characteristic feature of the line studied. A large metacentric chromosome persistently present in the cells was accepted as a line marker.

Animals↗
PubMed1989

[Megakaryocytic myelosis--clinical aspects, morphology and platelet function].

The study reviews 22 patients, aged between 19 to 73 years, with megakaryocytic myelosis. In the course of the disease 11 patients presented haemorrhagic manifestations, 12 patients thrombotic complications, and 6 patients the association of haemorrhage and thrombosis. The maximum platelet counts ranged from 524 to 2700 x 10(9)/l. The bone marrow showed a conspicuous megakaryocytic proliferation with polyploidy of the nuclei, giant forms and clusters. Marked alterations of erythro- and granulopoiesis were excluded. There was no evidence for a reactive thrombocytosis in any case. Patients with thrombocythaemia due to megakaryocytic myelosis (n = 14), with secondary thrombocytosis of various origin (n = 16), and a control group of healthy donors (n = 20) were investigated with respect to the aggregation behaviour and the total calcium content of blood platelets. In 9 of 14 patients with megakaryocytic myelosis platelet rich plasma did not respond to epinephrine (15 mumol/l), a concentration which induced at least weak aggregation in 14 of 16 patients with secondary thrombocytosis and also in healthy subjects. In patients with megakaryocytic myelosis the mean extent of aggregation induced by epinephrine, collagen or adenosine diphosphate was significant lower as compared to controls whereas in patients with secondary thrombocytosis in most cases this parameter did not differ significantly from that of controls. The total calcium content of platelets was significantly lower in both groups of patients as compared to controls. In 14 patients with megakaryocytic myelosis the concentration of the glycoprotein (GP) IIb-IIIa complex was estimated by crossed- and rocket-immunoelectrophoresis and found to be decreased in 8 of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗