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PubMed2002

Prognostically important chromosomal aberrations in soft tissue sarcomas: a report of the Chromosomes and Morphology (CHAMP) Study Group.

Cytogenetic analysis has not only provided important information on the pathogenesis of soft tissue tumors but, by disclosing distinct chromosomal rearrangements in different histopathological entities, has also come to serve as a valuable diagnostic tool. Little is known as yet about the potential prognostic impact of cytogenetic features detected in these tumors. A total of 239 benign and 221 malignant soft tissue tumors with clonal chromosome aberrations were subdivided according to general karyotypic features, such as degree of complexity and ploidy level, and rearrangements of specific chromosomal regions. The cytogenetic variables were analyzed regarding clinical outcome, using time to metastasis as the end point. Selected variables were then compared with established clinicopathological predictors of metastasis development. When the entire material was considered, 167 of 268 investigated cytogenetic variables were associated with clinical outcome. Focusing on the subset of 151 patients with high-grade sarcoma, 17 variables were identified that, besides grade and size, were associated with increased risk of metastasis development. A final Cox regression analysis identified five independent cytogenetic predictors of adverse outcome; breakpoints in chromosome regions 1p1, 1q4, 14q1, and 17q2, and gain of regions 6p1/p2. An increasing effect on metastatic risk was seen with increasing involvement of the selected cytogenetic variables, even when different histopathological types were studied separately. We conclude that cytogenetic data provide independent prognostic information in soft tissue sarcomas. Furthermore, our results point to specific areas of the genome harboring genes that may influence the metastatic potential of sarcoma cells.

Adolescent↗
PubMed1992

[Chiasma distribution in the lampbrush chromosomes of the chicken Gallus gallus domesticus: hot spots of recombination and their possible role in proper dysjunction of homologous chromosomes at the first meiotic division].

Chiasma distribution in the lambrush chromosomes of the chicken Gallus gallus domesticus was studied. The data of the authors show that the general pattern of chiasmata in the interstitional region of chromosomes corresponds to the Poisson distribution. However, in the telomeric and subtelomeric regions of all chicken macrochromosomes one can see chiasma as a rule. In the half of 140 microchromosomes from 24 different oocytes, there are also the telomeric chiasmata. On the basis of this observation, it may be predicted that there are hot spots of recombination near or into the telomeric GC-rich heterochromatic bands of chicken chromosomes. We suggest that these hot spots of recombination near the telomeres are a necessary facility for not only macrochromosomes but all microchromosomes as well to have at least one chiasma. The constant presence of at least one chiasma in a bivalent in needed for correct disjunction of homologous chromosomes at the first meiotic division.

Animals↗
PubMed2005

Chromosomal duplications along the Y-chromosome and their potential impact on Y-STR interpretation.

Y-chromosome short tandem repeat (Y-STR) markers are being used as potential tools for distinguishing low levels of male DNA in the presence of excess female DNA as is present in many sexual assault samples. Usually single copy Y-STR loci produce a single amplicon in single source samples, and thus the observation of multiple peaks at such a locus could suggest to an analyst that a mixture of more than one male contributor is present in the tested sample. However, many regions of the Y-chromosome are duplicated or even triplicated in some individuals and this fact can thus complicate potential mixture interpretation. Reasons for the presence of duplications at multiple loci within a single sample are explored in the context of Y-STR marker location along the chromosome. True male-male mixtures commonly exhibit more than one locus-specific PCR product across multiple Y-STR loci that are not adjacent to one another on the Y-chromosome. In addition, duplicated loci typically possess alleles that differ by only a single repeat unit and possess similar peak heights.

Alleles↗
PubMed1982

[Scanning electron microscopy of metaphase chromosomes. I. The relation of chromosome morphology to the method of drying the preparations].

The surface of metaphase chromosomes fixed in methanol--acetic acid (3 : 1) has been examined by high resolution scanning electron microscopy. The chromosomes were prepared both by the standard method (spread on the slide) and as isolated cells. The absence of microconvules on the surface of air-dried chromosomes is considered to be result of destruction of fibrillar structure by surface tension forces, rather than of covering of chromosomes by remnant of the cytoplasmic membrane.

Animals↗
PubMed1982

Nuclear envelope formation around metaphase chromosomes: chromosome decondensation and nuclear envelope reconstitution during mitosis.

The hypothesis of a possible correlation between reconstitution of the nuclear envelope and decondensation of the chromosomes has been experimentally examined. In the presence of colcemid, which delays C-metaphase chromosome decondensation for several hours, compared to normal mitosis, nuclear envelope formation is also significantly delayed. On the contrary, the treatment of the cells with a hypotonic solution, resulting in some swelling of metaphase chromosomes, induces the establishment of contacts between these chromosomes and membranes and the formation of an envelope around them. A new method, by which micronuclei are formed under hypotonic treatment, is discussed.

Animals↗
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↗
PubMed1996

Human sperm chromosome analysis--study on human sperm chromosome mutagenesis induced by carbon disulfide.

The aim of this study was to investigate the effect CS2 of on human sperm chromosomal aberration. The human sperm/hamster egg fusion technique was used to analyze 203 human sperm chromosome complement from 9 healthy volunteers. The incidence of numerical aberration was 1.0% and that of structural chromosome aberration was 5.9% and total abnormalities was 6.9%. Structural aberrations consisted of breaks, deletions, centric rings, fragments, and chromatid exchange. The results from high concentration group (10 mumol.L-1 CS2) showed that the incidence of chromosomal aberration rate was significantly higher than that of the control group. The results indicate that high concentration of CS2 might directly cause mutagenesis of the germ cell.

Adult↗
PubMed1996

[A study on complicated chromosome translocation by fluorescence in situ hybridization (FISH) of G-banded chromosomes].

An experimental method of fluorescence in situ hybridization (FISH) with conventionally G-band chromosomes was developed to analyze the complex chromosome rearrangements of patients. In order to obtain optimal results of both G-banding and fluorescence signals, it was essential that G-banded chromosomes were fixed with formaldehyde prior to fluorescence in situ hybridization. The karyotype of a patient with spontaneous abortion might be described as 46, XX, t(1; 5; 12) (1pter-->1q25 : : 12q24-->12qter; 5qter-->5p11 : : 1q25-->1qter; 12pter-->12q24 : : 5p11-->5pter) by the analysis of conventional cytogenetics. However, her karyotype should be identified as 46, XX, t(1; 5; 12) (1pter-->1q23 : : 12q22-->12qter; 5qter-->5p11 : : 1q25-->1qter; 12pter-->12q22 : : 1q23-->1q25 : : 5p11-->5pter) with this newly established method. This investigation indicates that this technique described above is a powerful tool to detect complex chromosome rearrangements of patients.

Adult↗
PubMed1996

[Studies on prematurely condensed chromosomes and induced condensed chromosomes with SEM].

The ultrastructure of prematurely condensed chromosomes (PCC) in BK cells and the CHO metaphase chromosomes (the PCC inducer) were studied with cell fusion technique and SEM. The methods for preparing complete specimens for SEM, were used to eliminate artifact as complete as possible, so the natural states of PCC ultrastructure, especially the ultrastructure of the early, mid, and late S-PCC, were observed for the first time. In the three phases of S-PCC multiple double strand helical structure were revealed, on the chromosome segments of BK cells. On the surface of CHO metaphase chromosomes which may induce PCC may regularly arrayed short hair-like loop-protrusions consisting of helical chromatin fibers were observed.

Animals↗
PubMed1997

Are rice chromosomes components of a holocentric chromosome ancestor?

Comparative genomics reveals that cereal genomes are composed of similar genomic building blocks (linkage blocks). By stacking these blocks in a unique order, it is possible to construct a single ancestral 'chromosome' which can be cleaved to give the basic structure of the 56 different chromosomes found in wheat, rice, maize, sorghum, millet and sugarcane. The borders of linkage blocks are defined by cereal centromeric and telomeric sites. However, a number of studies have shown that telomeric heterochromatin has neocentromeric activity, implying that linkage blocks are in fact defined by centromeric-like sites with conserved sequences. The structure of the ancestral cereal genome thus resembles a holocentric chromosome, which is the chromosome structure shared by the closest relatives of the Gramineae, the Cypericeae and Juncaceae.

Biological Evolution↗
PubMed2003

Characterization of a chromosome 8-derived minute marker chromosome using microdissection and FISH in a boy with growth retardation.

In a 9-year-old boy referred because of growth retardation, chromosome analysis showed the presence of a minute marker chromosome in 75% of the metaphases examined. The application of microdissection in combination with fluorescence in situ hybridization demonstrated that the marker was derived from the centromere region of chromosome 8, the karyotype being: mos 47,XY,+mar.ish der(8)(D8Z1+)[75]/46,XY[25]. The clinical and cytogenetical findings are compared with cases previously reported in the literature.

Child↗
PubMed2006

Genotoxicity of hydrochlorothiazide in cultured human lymphocytes. I. Evaluation of chromosome delay and chromosome breakage.

Hypertension is often treated with diuretics, like hydrochlorothiazide (HCTZ). Previous results on the in vitro genotoxicity of HCTZ are equivocal. In the present study, we have evaluated the genotoxicity of HCTZ in cultured human lymphocytes using the Cytokinesis Blocked Micronucleus (CBMN) assay. In addition, micronucleus (MN) induction was analyzed by Fluorescence In Situ Hybridization (FISH) with an alpha-satellite DNA centromeric probe to distinguish between clastogenic and aneugenic effects. Lymphocyte cultures from 32 healthy adults were exposed to 5 and 40 microg/ml HCTZ. Age, gender, and smoking were evaluated as factors affecting the MN analysis. We found that HCTZ increased MN frequencies. FISH analysis revealed that HCTZ exerts its genotoxicity more strongly at the 40 microg/ml concentration, and principally through chromosome delay (aneugenicity). Multiregression analysis of our results confirmed the known effect of age and gender on MN induction in human lymphocytes. Smoking was also a confounding factor for MN induction, especially for centromere-negative MN frequencies. Under the experimental conditions used, only age had a clear positive effect on the response of lymphocytes to HCTZ. These data indicate that HCTZ produces micronuclei in cultured human lymphocytes by a mechanism that involves chromosome delay and to a lesser extent through chromosome breakage.

Adult↗
PubMed1993

Mapping of the human NMDA receptor subunit (NMDAR1) and the proposed NMDA receptor glutamate-binding subunit (NMDARA1) to chromosomes 9q34.3 and chromosome 8, respectively.

A role for the N-methyl-D-aspartate (NMDA) receptor in the molecular pathology underlying Huntington disease (HD) has been proposed on the basis of neurochemical studies in HD and the ability of the NMDA receptor to mediate neuronal cell death. The molecular cloning of the human NMDA receptor subunit (NMDAR1) and a proposed glutamate-binding subunit of the NMDA receptor (NMDARA1) have provided an opportunity to test the hypothesis that either of these genes might be directly involved in the causation of HD. We have mapped NMDAR1 to 9q34.3 using in situ hybridization studies and NMDARA1 to human chromosome 8 using a somatic cell hybrid panel. Because the gene causing HD has been localized to chromosome 4p16.3, the chromosome assignments reported here are inconsistent with either of these genes playing a causative role in the molecular pathology of HD. However, it is noteworthy that the gene for torsion dystonia has also been localized by genetic studies to 9q34.3, the same regional map location as NMDAR1.

Animals↗
PubMed1994

A 6.5-Mb yeast artificial chromosome contig incorporating 33 DNA markers on the human X chromosome at Xq22.

The Xq22 region of the human X chromosome contains genes for a number of inherited disorders. Sixty-nine yeast artificial chromosome clones have been isolated and assembled into a 6.5-Mb contig that contains 33 DNA markers localized to this region. This contig extends distally from DXS366 to beyond DXS87 and includes the genes involved in X-linked agammaglobulinemia (btk), Fabry disease (GLA), and Pelizaeus-Merzbacher disease (PLP). The order of markers in this contig is consistent with the known genetic and physical mapping information of Xq22. This cloned material provides a source from which to isolate other genes located in this part of the X chromosome.

Adult↗
PubMed1994

Human type I pituitary adenylate cyclase activating polypeptide receptor (ADCYAP1R): localization to chromosome band 7p14 and integration into the cytogenetic, physical, and genetic map of chromosome 7.

The gene encoding the human type I pituitary adenylate cyclase activating polypeptide receptor (ADCYAP1R1) was mapped to chromosome 7 by PCR analysis of genomic DNA from a human/rodent somatic cell hybrid mapping panel. This assignment was confirmed and the gene localized to chromosome band 7p14 by fluorescence in situ hybridization. A yeast artificial chromosome containing ADCYAP1R1 was identified in the CEPH "B" Mega-YAC library. This YAC includes two highly polymorphic dinucleotide repeat sequences that will facilitate genetic studies of the contribution of ADCYAP1R1 in disease states of the central nervous and neuroendocrine systems.

Animals↗
PubMed1994

Yeast artificial chromosome and radiation hybrid map of loci in chromosome band 8p22, a common region of allelic loss in multiple human cancers.

Polymorphic alleles at loci such as LPL (lipoprotein lipase) and MSR (macrophage scavenger receptor) in chromosome band 8p22 are frequently lost during the genesis of several types of human cancer, including colorectal, non-small cell lung, hepatocellular, and prostatic carcinomas. A physical map of 31 published or novel probes and sequence-tagged sites in this genetic region was constructed using a radiation hybrid panel and the CEPH (Centre d'Etude du Polymorphisme Humain) yeast artificial chromosome (YAC) library. Thirty-six overlapping YACs defined a physical order for the following polymorphic markers: tel-D8S26-D8S511-D8S549-MSR-D8S254-D8S233- D8S261-D8S21-LPL-D8S258-cen. These maps unify small consensus regions of allelic loss on chromosome 8p defined by restriction fragment length polymorphisms with more informative PCR-based polymorphisms and widely available YAC mapping resources.

Alleles↗
PubMed1995

Mapping of the gene for the Mel1a-melatonin receptor to human chromosome 4 (MTNR1A) and mouse chromosome 8 (Mtnr1a).

The pineal hormone melatonin elicits potent circadian and reproductive effects in mammals. We report the chromosomal location of the gene for the Mel1a-melatonin receptor that likely mediates these circadian and reproductive actions. PCR analysis of human-rodent somatic cell hybrids showed that the receptor gene (MTNR1A) maps to human chromosome 4q35.1. An interspecific backcross analysis revealed that the mouse gene (Mtnr1a) maps to the proximal portion of chromosome 8. These loci may be involved in genetically based circadian and neuroendocrine disorders.

Animals↗
PubMed1995

The orphan nuclear receptor ROR alpha (RORA) maps to a conserved region of homology on human chromosome 15q21-q22 and mouse chromosome 9.

ROR alpha is a novel member of the steroid/thyroid/retinoid receptor superfamily with unique DNA-binding properties. We have mapped the RORA gene by fluorescence in situ hybridization to human chromosome 15q21-q22. To map the mouse Rora gene, a partial mouse cDNA clone was isolated from brain. Using interspecific backcross analysis, we have mapped the Rora gene to mouse chromosome 9. This places the human RORA gene in the proximity of the PML gene, which is involved in a reciprocal chromosomal translocation t(15:17) with the RARA gene in patients with acute promyelocytic leukemia.

Animals↗

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