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PubMed1987

Studies on radiation-induced chromosome aberrations in mouse spermatocytes. I. Stage specificity and dose-response relationships of chromosome aberrations induced in mouse primary spermatocytes following X-irradiation.

The cytological analysis of chromosome aberrations induced at diplotene, mid-pachytene, zygotene and leptotene stages following X-irradiation was performed at diakinesis-metaphase I in mouse spermatocytes. The dose-response relationships fitted well to linear equations for deletion-type aberrations at each stage, and to linear-quadratic equations for exchange-type aberrations at all stages except for leptotene. The radiosensitivity to chromosome aberration induction tended to increase gradually with progression through synaptic and post-synaptic stages, diplotene being the most sensitive. Chromatid exchanges were hardly observed at leptotene, the aberrations being mainly isochromatid fragments. On the contrary, chromatid exchanges and isochromatid deletions were mainly observed at later stages (zygotene-diplotene). The specificity of chromosome aberration induction in primary spermatocytes might be influenced by chromatin organization and chromosomal configuration peculiar to meiotic cells.

Animals↗
PubMed1994

Prediction of human cell radiosensitivity: comparison of clonogenic assay with chromosome aberrations scored using premature chromosome condensation with fluorescence in situ hybridization.

PURPOSE: The purpose of the present investigation was to determine whether chromosome aberrations scored by premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) can predict the radiosensitivity of human cell lines, thereby providing a possible means of assessing the in situ radiosensitivity of normal tissues and the radiocurability of individual human cancers. METHODS AND MATERIALS: We used four cells lines of different radiosensitivity: normal human fibroblasts (AG1522), ataxia-telangiectasia fibroblasts (AT2052), a human fibrosarcoma cell line (HT1080), and a human melanoma cell line (melanoma 903). These were irradiated in plateau phase with a range of doses and assessed both for clonogenic cell survival and for aberrations in a single chromosome (number 4) immediately after, and 24 h after irradiation. RESULTS: The initial number of breaks in chromosome 4 was proportional to irradiation dose and was identical for all the different human cell lines, irrespective of radiosensitivity. On the other hand, the number of chromosome 4 breaks remaining 24 h after irradiation reflected the radiosensitivity of the cells such that the relationship between residual chromosome aberrations and cell survival was the same for the different cell lines. CONCLUSIONS: These results suggest that the scoring of chromosome aberrations in interphase using FISH with PCC holds considerable promise for predicting the radiosensitivity of normal and tumor tissues in situ.

Ataxia Telangiectasia↗
PubMed1980

DNA repair and chromosome aberrations: the effect of cytosine arabinoside on the frequency of chromosome aberrations induced by radiation and chemicals.

The frequency of x-ray-induced chromosome aberrations in G0 human lymphocytes was greatly increased when cells were incubated with cytosine arabinoside (ara-C) after irradiation. The frequency of dicentrics increased with increasing ara-C incubation times (one, two, and three hours). Lymphocytes from Down syndrome individuals were more sensitive to aberration induction by x-rays in G0, and the increase in dicentric frequency with ara-C incubation was much more rapid than with normal cells. When G2 normal lymphocytes were x-irradiated and incubated for two or three hours with ara-C until fixation, there was a large increase in deletion frequency compared to cells x-irradiated and incubated in the absence of ara-C. However, no exchanges were observed in the presence of ara-C, compared to 0.29 per cell as when x-rays alone were given. These results form the basis for a discussion of the mechanism of aberration induction by x-rays. Experiments with two chemicals, 4-nitroquinoline-N-oxide and methyl methanesulfonate, show that chromosome-type aberrations can be induced in G1 treated lymphocytes incubated with ara-C. However, these chemicals, in the absence of ara-C incubation, induced no aberrations in G1 at the concentrations used. The mechanism of aberration induction is discussed, particularly in terms of whether or not chemicals can be defined as S-phase dependent.

4-Nitroquinoline-1-oxide↗
PubMed1997

Clonal chromosome aberrations with monosomy of chromosome 8 in a case of grade III chondrosarcoma.

We report cytogenetic findings in a case of grade III chondrosarcoma. Complex clonal chromosome aberrations including monosomy of chromosomes 4, 8, 13, and a consistent t(5;14)(q23;p12) were observed in all cells. There were no structural or numerical anomalies involving chromosome 12. The complexity of the chromosome aberrations reflect the advanced stage of this chondrosarcoma; we suggest a possible involvement of the EXT1 gene located on chromosome 8.

Aged↗
PubMed1985

Studies on chromosome aberrations in the eggs of mice fertilized in vitro after irradiation. II. Chromosome aberrations induced in mature oocytes and fertilized eggs at the pronuclear stage following X-irradiation.

Cytological analysis of the first-cleavage metaphase of eggs exposed to X-rays at the mature oocyte stage or the pronuclear stage 4 h after fertilization was performed using the in vitro fertilization technique. The frequency of chromosome aberrations in irradiated mature oocytes increased exponentially with dose, the dose-response relationship being best fitted to the linear-quadratic model. On the other hand, in eggs irradiated at the early pronuclear stage, the frequency increased linearly with dose and the dose-response relationship was best fitted to the linear model. The aberrations were mainly chromosome-type (mature oocytes: 86.0% and pronuclear stage: 88.5%) and the majority were fragments in both cases. Eggs in the early pronuclear stage were markedly more radiation-sensitive than mature oocytes. A comparison of the present results with the previous ones (Matsuda et al., 1985b) showed that the sensitivities to induction of chromosome aberrations were in the order: egg at early pronuclear stage (highest) greater than mature oocyte greater than mature sperm.

Animals↗
PubMed2000

Induction of premature chromosome condensation by a phosphatase inhibitor and a protein kinase in unstimulated human peripheral blood lymphocytes: a simple and rapid technique to study chromosome aberrations using specific whole-chromosome DNA hybridization probes for biological dosimetry.

We developed a simple and rapid method to study chromosome aberrations involving specific chromosomes using unstimulated human peripheral blood lymphocytes (HPBL). Premature chromosome condensation (PCC) was induced by incubating unstimulated HPBL in the presence of okadaic acid (OA, a phosphatase inhibitor), adenosine triphosphate (ATP), and p34(cdc2)/cyclin B kinase [an essential component of mitosis-promoting factor (MPF)], which eliminated the need for fusion with mitotic cells. OA concentration and duration of incubation for PCC induction was optimized using mitogen-stimulated HPBL; a final concentration of 0.75 microM incubated for 3 h was optimum, resulting in approximately 20% PCC yield. In unstimulated HPBL, PCC was induced by the addition of p34(cdc2)/cyclin B kinase at concentrations as low as 5 units/ml to a cell culture medium containing OA. Increases in the concentration of p34(cdc2)/cyclin B kinase from 5 to 50 units/ml resulted in a concentration-dependent increase in PCC yield (30% to 42%). We demonstrate that this technique of inducing PCC in unstimulated HPBL is suitable for studying radiation-induced aberrations involving a specific chromosome (chromosome 1) after 24 h repair using a whole-chromosome in situ hybridization probe and chromosome painting. Cells with aberrant chromosome number 1 are characterized with more than two chromosome spots. The frequency of cells with aberrant chromosome 1 increased with 60Co gamma-radiation doses in the region 0-7.5 Gy. The observed dose-effect relationship for the percentage of cells with aberrant chromosome 1 (Y) was explained by using both a linear [Y=(2.77+/-0.230)D+0.90+/-0.431, r(2)=0.966] and a nonlinear power [Y=(5.70+/-0.46)D((0.61+/-0.05)), r(2)=0.9901) model. This technique can be applied to biological dosimetry of radiation exposures involving uniform whole-body low linear energy transfer (LET) exposures.

CDC2 Protein Kinase↗
PubMed1974

Variation of spontaneous occurrence rates of chromosomal aberrations in the second chromosomes of Drosophila melanogaster.

After accumulating mutations by the aid of marked inversions, spontaneous occurrence rates of chromosome aberrations were estimated for 1148 chromosome lines that originated from five stem line second chromosomes of Drosophila melanogaster. In chromosome lines originating from three stem chromosomes (CH, PQ, and RT), mutations were accumulated for 7550, 7252, and 7256 chromosome generations, respectively, but no structural change was detected. For the chromosome lines that originated from the other two stem chromosomes, the situation was different: Twenty aberrations (19 paracentric inversions and 1 translocation between the second and the third chromosomes) during 45990 chromosome generations took place in the 500 chromosome lines derived from stem line chromosome (AW), and 92 aberrations (83 paracentric inversions, 6 pericentric inversions, 2 translocations between the second and the third chromosomes and 1 transposition) arose during 45006 chromosome generations in the 500 chromosome lines derived from stem line chromosome (JH). For the AW group the occurrence rate becomes 0.00043 per chromosome per generation for all aberrations and 0.00041 for inversions. For the JH group the corresponding rates are 0.00204 and 0.00198, respectively.-A non-random distribution of the breakpoint on the salivary gland chromosome was observed and the breakpoints were concentrated in the regions 26, 29, 33, and 34.-The cytoplasms and the chromosomes (other than the second chromosomes) were made approximately uniform throughout the experiments. Thus, this remarkable variability in the occurrence rate is most probably due to the differences in one or more chromosomal elements on the original five stem chromosomes. The mutable chromosomes (AW and JH) appear to carry a kind of mutator factor such as hi (Ives 1950).

Animals↗
PubMed1990

[Chromosome aberrations in chronic and lupus glomerulonephritis ].

The levels of aberration of chromosomes in peripheral blood leucocytes were investigated in patients with chronic and lupoid glomerulonephritis considering the clinical variants and morphological forms of the disease. In chronic glomerulonephritis high levels of chromosome aberration were found in patients with nephrotic type; in lupoid glomerulonephritis the frequency of chromosome aberration was higher in patients with active glomerulonephritis. Chronic renal failure did not essentially change the level of chromosome aberration both in chronic and lupoid glomerulonephritis. In different morphological forms of glomerulonephritis the frequency of chromosome aberration was determined by the clinical variant of the disease.

Adolescent↗
PubMedDate not supplied

Delayed cell cycle kinetics and chromosome aberrations induced by girostan in human peripheral blood lymphocytes (PBL) in vitro. Note 2. Chromosome aberrations.

Human peripheral blood lymphocytes (PBL) maintained in vitro for 72 hours were labeled with 5-Bromodeoxyuridine (BrdU) at 50 ug/ml and concomitantly treated with girostan at 1.5; 2 and 2.5 ug/ml during the last 13; 11; 9; 7; 5 and 3 hours before cells gathering to estimate the chromosome aberrations induced during different stages of cell cycle traverse as determined by incorporation banding pattern observed in metaphase spreads; similar untreated cultures but labeled with BrdU were set-up as controls in order to determine the phase of cell cycle traverse in the moment when girostan was given to the cultures. Chromosome aberrations were induced especially when treatments were performed 13 and 11 hours before fixation. Their frequency was rather low (up to 7% of observed metaphases) and the lesions were not dose-related. When cells were treated during S- and G2-phases, chromatid and chromosome gaps, breaks, deletions and fragments were observed. Chromatid rearrangements as tri- or quadriradials were seen only when girostan was given during middle S-phase indicating that DNA breaking and misrejoining are successive steps during the same replication round. When cells were exposed to BrdU and girostan during the last 3 hours of incubation, no labeled metaphase or structural aberration was seen, but spiralization defects and premature separation of despiralated chromatids frequently appeared. This could indicate that the induction of chromosome condensing factor and of proteins responsible for normal centromere activity is disturbed when girostan treatment is applied during the last part of G2-phase, in the immediate proximity of mitosis.

Bromodeoxyuridine↗
PubMed1975

Three cases of minor chromosomal aberrations discovered by prenatal chromosome determination.

A case of pronounced secondary constriction of a chromosome belonging to pair N0. 9, a case of deletion of the short arms of one of the chromosomes in pair No. 13, and a case of partial trisomy of the distal portion of a chromosome in pair No. 14 were discovered by prenatal chromosome determination. Analysis of the parents' karyotypes enabled the clinical importance of the three different chromosomal aberrations to be elucidated.

Abortion, Induced↗
PubMed1988

[Identification of aberrant chromosomes based on the morphometry of the synaptonemal complexes in a sterile male mouse].

The synaptonemal complexes (SCs) of surface-spread spermatocytes of male mouse from the F1 progeny of a male exposed to a mutagen have been examined by electron microscopy. Nonreciprocal translocation was recognised in analysing configuration of SC. Electron microscope analysis revealed translocation in 100% pachytene spermatocytes and light microscope analysis of air-dried metaphase spermatocytes demonstrated this in 58% cells. Different types of association of X-chromosome with aberrant chromosomes were discovered in pachytene spermatocytes. Computer analysis of relative length of SCs permits to detect a nonreciprocal translocation from chromosome 4 to chromosome 16. The length of the translocated fragment was determined to be from 66 to 75% of the length of chromosome 4. It has been impossible to discover a telomere fragment of chromosome 16, because the break point of chromosome 16 is too close to the distal end.

Animals↗
PubMed1997

Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Part III: Evaluation of the effect of the induced alpha and beta activity on the chromosomal aberration yield.

AIM: Further experiments were performed to explain a difference in chromosomal aberration yield found between samples cultivated immediately after fission neutron irradiation and samples which were cultivated with 96 h delay after irradiation. MATERIAL AND METHOD: Human peripheral blood samples were irradiated in mixed fission neutron/gamma field (1800 s) and biological effect assessed in the mean of analysis of unstable chromosome aberrations with a time delay in culturing cells of 12, 24, 48, and 96 h. Additional measurements were performed on irradiated and blank blood samples with the aim to detect any increase in alpha and beta activity after fission neutron irradiation. No difference was found. Results were compared to theoretically calculated values of the alpha and beta activity released from natural radioactive isotopes. RESULT AND CONCLUSION: As a conclusion it is shown that in our experimental conditions the secondary effects resulting from nuclear transformations of natural or induced radioactive isotopes, recoil reactions and accompanying alpha, beta, and gamma radiation are not the reason for the increase observed in chromosomal aberration yield in blood samples cultured with a time delay of at least 24 hours.

Alpha Particles↗
PubMed1992

Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Part II: Evaluation of the effect of the induced Na-24 activity on the chromosomal aberration yield.

Blood samples were spiked with Na-24 to study the separate effect of this nuclide on the incidence of chromosomal aberrations in neutron irradiated blood samples. A delay of 96 h was allowed before cultivation, so the results of chromosomal aberration analysis could be compared with the results obtained by direct irradiation of blood samples with U-235 fission neutrons [7]. The absorbed dose was calculated using a simple conservative model. From the results obtained we can conclude that Na-24 alone was not the reason for the difference in the incidence of chromosomal aberrations between blood samples cultivated immediately after "in vitro" irradiation by U-235 fission neutrons and samples which were cultivated after 96 h storage.

Absorption↗