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Cell-growth kinetics and karyotype analysis of human memory lymphocytes responding to alloantigen and mitogen.

Peripheral-blood lymphocytes were primed in vitro with the mitogen phytohemagglutinin (PHA) or with allogeneic cells and their memory responses studied following sequential restimulation with either mitogen or alloantigen. Chromosome preparations were made every 24 hours following exposure to the stimulating agents. Cultures were labeled with BUdR for sister-chromatid staining of the chromosomes which provided information about the kinetics of cell growth and rates of sister chromatid exchange. Cultures containing n BUdR were used for the investigation of cell karyotypes after chromosome-banding. Following PHA as well as alloantigen restimulation, an earlier reaction of the responding cells was observed. The peak response after the first stimulation was found at 120 h with allogeneic stimulation and at 60 h with mitogen stimulation. In the second round of stimulation, the peak occurred after 48 h (allogeneic) and 36 h (PHA) and following the third stimulation after 36 h (allogeneic) and 24 h (PHA). The speed of cell growth was decreased following restimulation with either alloantigen and mitogen. In contrast to the allogeneic restimulation, the number of cells responding after PHA restimulation was decreased. No systematic numerical or structural aberration of the karyotype was detected following repeated stimulation with either alloantigen or mitogen. In this sense, the lymphocyte subpopulations selected by repeated stimulation did not differ from the starting material. On the other hand, the sister-chromatid exchange (SCE) frequency was increased following allogeneic restimulation, whereas it remained constant with PHA restimulation.

Humans↗

The synaptonemal complexes of Caenorhabditis elegans: pachytene karyotype analysis of male and hermaphrodite wild-type and him mutants.

Only five synaptonemal complexes (SC), representing the 5 autosomes, are present in wild-type, him-4 and him-8, Caenorhabditis elegans males, whereas there are six SCs, accounting for 5 autosomal bivalents and the XX bivalent, in the C. elegans hermaphrodite. The univalent X chromosome of the male is present as a heterochromatic 'X-body' in spermatocyte pachytene nuclei. The XX bivalent in wild-type, him-4 and him-8 hermaphrodites (SC1, 2.5 microns in length) represented 6% of the total karyotype length and a SC of this size is missing from the respective male karyotypes. This corresponds with the fact that the total male karyotype length is only approximately 94% that of the hermaphrodite. Associated with the central element of the SC are structures termed 'SC knobs' that were first described in the wild-type hermaphrodite. The six SC knobs present in the wild-type hermaphrodite oocyte pachytene nuclei and the two SC knobs in the male spermatocyte pachytene nuclei are apparently randomly placed with the exception that they are never found at the ends of the SC. This is also true in him-4 and him-8 in which case there are 3 and zero SC knobs in the hermaphrodites, respectively, and one SC knob each in the male pachytene nuclei. The decrease in number of SC knobs in hermaphrodite to male represents a true sex difference. The presence or absence of the SC knobs may influence the X chromosome nondisjunction process and this effect is not localized to the region of the SC on which the SC knob is located.

Animals↗

Karyotype analysis of Leishmania species and its use in classification and clinical diagnosis.

Chromosomes of four species of Leishmania represented by ten different geographic isolates were analyzed by pulsed field gradient gel electrophoresis (PFG) to assess chromosome stability in these parasitic protozoans. Among different geographic isolates of the same subspecies, more than two-thirds of chromosomes had similar sizes, ethidium bromide staining intensities, and locations of alpha,beta-tubulin genes. However, among New World Leishmania, members of different species or subspecies have fewer than one-third of their chromosomes in common. Therefore, PFG karyotypes of Leishmania exhibit intraspecific variability similar to that reported for other parasitic protozoans. The greater similarities of the karyotypes of members of the same Leishmania subspecies may indicate that they represent valid taxa. These similarities also allowed the use of PFG in clinical diagnosis for rapid and accurate typing of patient isolates.

Chromosomes↗

Investigation of human giardiasis by karyotype analysis.

The patterns of transmission of Giardia lamblia and the potential contribution of strain differences to pathogenicity of infection is poorly understood. We used pulsed field gradient gel electrophoresis (PFGE) to separate chromosome-sized DNA molecules of 22 stocks of G. lamblia isolated from 13 individuals (6 symptomatic, 7 asymptomatic) living in Jerusalem. PGFE gels run under a variety of conditions revealed up to nine ethidium bromide-stained bands per isolate ranging in size from 0.7 to greater than 3 megabasepairs. Relative staining intensities indicated that some bands contained multiple chromosomes. Major differences in the number, size, and intensity of bands allowed a clear differentiation of the karyotypes of isolates from each of the different individuals. This is in contrast to previous studies where the karyotype of different isolates have been strikingly homogeneous. Hybridization of Southern blots with surface antigen, beta-tubulin, and ribosomal RNA genes revealed that these gene families were distributed to different sized chromosomes amongst the different isolates. PFGE thus revealed major differences in the karyotypes of different G. lamblia isolates that were obtained over a short period of time from a relatively confined geographic area. In contrast, karyotypes of isolates established either by direct cultivation of duodenal trophozoites or by excystation of stool cysts from the same individuals were almost identical. Also, isolates from the same individuals obtained over a prolonged period of time revealed only minor differences in their karyotype, suggesting that recurrent infection can be caused by genetically similar organisms. We conclude that chronic giardiasis can result from recurrence of occult infection or reinfection from a common source.

Adolescent↗

Human intraspecific somatic cell hybrids: a genetic and karyotypic analysis of crosses between lymphocytes and D98/AH-2.

A number of human intraspecific hybrids were produced by fusing the 8-azaguanine-resistant cell line D98/AH-2 with PHA-stimulated lymphocytes from a normal human male, followed by selection in HAT medium. The parent cells differed in zymogram patterns for 4 enzyme systems. Hypoxanthine-guanine phophoribosyltransferase was missing in D98/AH-2 and was determined in the hybrids by the normal gene derived from the lymphocyte donor's X chromosome. The HL-A antigens of the lymphocyte donor as well as the W28 specificity from HeLa were easily recognized by a cytotoxicity assay on the hybrid cells, while D98/AH-2 itself was not killed in the normal way by any HL-4 typing sera. The initial hybrid karyotype in all lines was relatively stable, but slow loss of chromosomes occurred following extended growth in culture. The importance of the culture conditions for the rate of chromosome loss was demonstrated. The behavior of several chromosomes was followed in the hybrids and their derivatives. There was relatively nonspecific loss of small numbers of chromosomes, showing that loss of chromosomes from both the D98/AH-2 and the normal lymphocyte parent can occur. Cell lines resistant to 6-thioguanine were selected from the sensitive hybrids. Most had lost the lymphocyte donor's X chromosome, thereby losing the only active allele for HGPRT present in the initial hybrids. However, one line, DMR41, apparently retained the X chromosome and may have a mutated allele for HGPRT. Two lines that are the products of spontaneous segregation are also described. DM4CS and DM17A.

Acid Phosphatase↗

[Karyotype analysis of clone L929 murine fibroblasts by using differential chromosome staining].

Karyological analysis of mouse fibroblasts L929 has been carried out using the differential staining of chromosomes (44-58% of the total chromosome number), and their derivatives, i.e. markers of the particular clone. Normal, non-rearranged chromosomes are mainly present in 1-3 copies, while the markers are available as a single copy only. The frequency of occurrence of diverse chromosomes differs from cell to cell, the total number of chromosomes in the cells being not constant. The modal class consists of 62-64 chromosomes. Two new chromosome markers were found after a repeated karyological analysis one year after the cultivation of cells under the standard conditions. A possible role of some chromosome aberrations in the process of transformation of mouse fibroblasts is discussed. The particular attention is given to alteration of chromosome 15.

Animals↗

A simplified method for fixation of human and mouse preimplantation embryos which facilitates G-banding and karyotypic analysis.

A reliable method for the fixation of large numbers of preimplantation embryos was developed to allow application of routine G-banding methods to preimplantation stage embryos. The technique resulted in minimal loss of embryos and was suitable for both 1-cell mouse embryos and multi-pronuclear human embryos. Application of this method will increase the information gained from chromosome studies of embryonic development.

Animals↗

Interphase karyotypic analysis of chromosomes 11, 17 and X in invasive squamous-cell carcinoma of the cervix: morphological correlation with HPV infection.

Human papillomavirus (HPV) infection has been widely implicated in cervical carcinogenesis, but it appears to be an early event, with other genetic abnormalities being required for biological transformation. In this study, interphase cytogenetic analysis of numerical abnormalities of chromosomes 11, 17 and X was performed on paraffin-embedded tissue sections from 25 invasive squamous-cell carcinomas of the cervix and compared with both histopathological features and the morphological distribution of HPV sequences as determined by in situ hybridisation. Numerical differences between chromosomes were identified in 76% of cases, with underrepresentation of chromosomes 11 and/or 17 relative to X in 64% of the total; 22 of 25 cases were HPV-positive, containing either HPV 16, 18 or 31. There was no relationship between the distribution of viral sequences and chromosomal pattern, suggesting that HPV infection precedes karyotypic changes. Our findings suggest that relative reduction in number of chromosomes 11 and 17 is important in the development of invasive cervical neoplasia and are consistent with the putative presence of relevant tumour-suppressor genes on these chromosomes.

Carcinoma, Squamous Cell↗

[Karyotype analysis during development of chronic myelocytic leukemia].

We report cytogenetic data concerning 9 patients with chronica granulocytic leukemia and eosinophilia at the onset and during the chronic phase of the disease before the blastic crisis. The cariotype analises in the intermediate phases allowed to determine the first changes which could be involved in the evolutionary events of the disease up to the moment in which the typical markers of the blastic crisis can be found.

Adult↗

Karyotype analysis of the plant-parasitic nematode Heterodera glycines by electron microscopy. 1. The diploid.

Heterodera glycines is a diploid amphimictic nematode with n = 9 chromosomes. Nine normal synaptonemal complexes (SC) were detected following 3-dimensional reconstruction of pachytene nuclei from electron microscopy of serial sections. Regions of unique 'modified synaptonemal complexes' (MSC) were observed along 2 SCs. These consist of a heterochromatic knob within which the SC appears either disorganized or stacked in layers of lateral elements. Its function is not known. Recombination nodules and 'cylindrical granular complexes', were not observed in H. glycines.

Animals↗

Pachytene karyotype analysis of tetraploid Meloidogyne hapla females by electron microscopy.

Pairing of homologous chromosomes results in the formation of 34 synaptonemal complexes (SC) at pachytene, corresponding to the 34 bivalents at metaphase I. No multivalent associations were observed and pairing occurs two-by-two. The modified SC, which lacks a central element, does not affect the pairing process. Only one end of the SC is attached to the nuclear envelope, although either end can attach. Total SC length and the number of recombination nodules in the tetraploid were about 1.5 times greater than in the diploid.

Aneuploidy↗

Tripronuclear human oocytes: altered cleavage patterns and subsequent karyotypic analysis of embryos.

Between 1 and 4% of human oocytes fertilized in vitro are tripronuclear. It has been reported that these tripronuclear oocytes can develop to grossly normal-appearing morulae and that chromosomally, these embryos could be triploid, diploid, or severely depleted. The etiology and proportion of apparently diploid and aneuploid embryos deriving from tripronuclear human oocytes is unknown. This study provides evidence for the first time that most (18 of 29) tripronuclear human oocytes cleave directly to 3-cells at the first cleavage division. These embryos have a severely abnormal (but not triploid) chromosomal complement. Furthermore, some (4 of 29) tripronuclear human oocytes cleave to 2-cells plus an extrusion, and these embryos are diploids, whereas some (7 of 29) cleave to 2-cells, and these embryos are triploid after the first cleavage division. These findings demonstrate that most tripronuclear human oocytes have an altered cleavage pattern at the first cleavage division, that most tripronuclear human oocytes (76% in this study) do not develop into triploid embryos, and that a correlation exists between the pattern of the first cleavage division and the subsequent karyotype of these embryos. Insight into the mechanisms by which these oocytes fail to develop into triploid embryos is also provided.

Aneuploidy↗

A prospective comparative study on fluorescence in situ hybridization (FISH) of uncultured amniocytes and standard karyotype analysis.

Fluorescence in situ hybridization (FISH) on uncultured amniocytes and standard cytogenetic analysis after amniocentesis have been performed for 904 samples. The experience with the FISH method and its clinical relevance is described in a large clinical pilot study. Commercially available chromosome-specific DNA probes for chromosomes 13, 18, 21, X and Y were used. FISH assays were performed from 12 weeks of gestation to the third trimester. In 96 per cent of the cases, hybridization was performed successfully. At least 50 nuclei for all probes could be counted in 88 per cent of the cases and in 8 per cent between 10 and 49 nuclei were scored. All trisomies 13, 18 and 21 and all cases with gonosomal aberrations were detected by FISH analysis with the exception of one case of trisomy 21 in which hybridization failed due to technical problems. Neither false-positive nor false-negative results were obtained with the DNA probes, in complete agreement with standard cytogenetics. In our experience, FISH is a valuable and reliable method for rapid diagnosis. Consequences of FISH diagnosis are discussed.

Amniocentesis↗

Molecular karyotype analysis of Cryptosporidium parvum: evidence for eight chromosomes and a low-molecular-size molecule.

We report improved separation of chromosome-sized DNA molecules of the coccidian parasite Cryptosporidium parvum with contour-clamped homogeneous electric fields (CHEF). We used scanning densitometry to determine that the most likely number of chromosomes is eight. Molecular probes consisting of cloned genes were used to distinguish each of five bands visible on CHEF gels. We have also identified a low-molecular-size DNA molecule possibly related to the 35-kb circular DNAs found in other Apicomplexa.

Animals↗

Karyotypic analysis in primary myelodysplastic syndromes.

Cytogenetics has provided new insights into the biology and pathogenesis of myelodysplastic syndromes. In patients with refractory anemia, it has provided proof of clonality and has helped differentiate chronic myelomonocytic leukemia from chronic myeloid leukemia. As a prognostic tool, cytogenetics has been predictive of duration of survival and leukemic transformation. However, its role as an independent prognostic factor compared with recent prognostic scoring systems remains to be determined. New techniques such as fluorescent in situ hybridization using chromosome-specific DNA probes may expand the usefulness of cytogenetics. The prognostic impact of cytogenetics may not be fully realized until more effective treatments become available.

Adult↗

A comprehensive karyotypic analysis on a newly established sarcomatoid hepatocellular carcinoma cell line SH-J1 by comparative genomic hybridization and chromosome painting.

We first established a sarcomatoid hepatocellular carcinoma cell line, designated as SH-J1, and applied comparative genomic hybridization and fluorescence in situ hybridization (FISH) with chromosome painting probes for the characterization of the chromosomal rearrangements. In the SH-J1 cell line, the pleomorphic spindle cells were arranged in bundles of interlacing patterns and were positive in immunohistochemical staining with hepatocyte-related markers. By G-banding and FISH, the chromosomal gains were detected at 6p and 17, whereas losses were observed at 3p21-pter, 3q27-qter, 4, 6q, 13pter-q11, 16, 18, 19p13, and Y.

Carcinoma, Hepatocellular↗

Karyotype analysis of Ascaris lumbricoides var. suum. Male and female pachytene nuclei by 3-D reconstruction from electron microscopy of serial sections.

Twelve synaptonemal complexes are present in both oocyte and spermatocyte pachytene nuclei of Ascaris lumbricoides var. suum, as determined by 3-D reconstruction of the nuclear contents from electron microscropy of serial sections and therefore, n=12 in the strain of Ascaris described here. In the female the heterochromatic end of each synaptonemal complex is attached to the nuclear envelope and the other end is free in the nucleoplasm. In the male neither end of the synaptonemal complex is attached, but there is a heterochromatic knob at one end of each complex. Five additional large heterochromatic masses are present in the spermatocyte nucleus and these may be the sex chromosomes described by earlier workers.

Animals↗