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PubMed2002

ST1571 (imatinib mesylate) reduces bone marrow cellularity and normalizes morphologic features irrespective of cytogenetic response.

The tyrosine kinase inhibitor STI571 (imatinib mesylate, Gleevec) is an effective treatment for chronic myeloid leukemia (CML). We examined bone marrow samples from 53 patients with CML who were receiving STI571 in 3 multicenter phase 2 trials to assess morphologic changes and cytogenetic response to this drug. In most patients with initially increased blasts, the bone marrow blast count rapidly decreased during STI571 therapy. Reductions in cellularity, the myeloid/erythroid ratio (commonly with relative erythroid hyperplasia), and reticulin fibrosis (if present pretreatment) also were seen in most patients, resulting in an appearance resembling normal marrow in many cases. Eighteen patients (34%) had some degree of cytogenetic response. Surprisingly, these striking morphologic changes occurred irrespective of any cytogenetic response to STI571. Thus, STI571 seems to affect the differentiation of CML cells in vivo, causing even extensively Philadelphia chromosome-positive hematopoiesis to exhibitfeatures resembling normal hematopoiesis.

Antineoplastic Agents↗
PubMed2003

Some difficult choices in cytogenetics.

In making a selection of features of these technologies, it is inevitable that some will be omitted that other cytogeneticists feel should have been included. The author could probably justifiably be accused of bias. However, based on experience in a laboratory that has used almost every type of assay mentioned in this chapter, the following opinions are offered about their current value in providing a routine malignancy cytogenetics service: 1. The foundation is still a conventional cytogenetic study, preferably with the use of an automated karyotyping system. 2. Added to this, there should be the capability of performing FISH studies using chromosome paints and gene-specific probes. Cytogenetics and FISH form a powerful partnership when backed by experienced cytogeneticists. MFISH or SKY are also useful if the laboratory can afford the considerable extra expense. CGH and fibre FISH are generally better suited to research projects, and at present have few applications in a routine diagnostics service. 3. At present, molecular methods such as RT-PCR mostly tend to produce results that have a greater need of confirmation by other techniques before they can be used for clinical management.

Cytogenetics↗
PubMed2000

Use of interphase cytogenetics in demonstrating specific chromosomal aberrations in solid tumors--new insights in the pathogenesis of malignant melanoma and head and neck squamous cell carcinoma.

The detection of structural and numerical chromosomal aberrations is an important part of the characterization of tumors and genetic diseases. The direct demonstration of DNA sequences in interphase nuclei and metaphases by fluorescence in situ hybridization (FISH) has been termed interphase cytogenetics. It has been proven as a powerful technique to detect specific aberrations in a wide variety of cell types, including paraffin-embedded tissue. Nowadays a standard method in leukemia and lymphoma, interphase cytogenetics contributes mainly to the diagnosis in these tumors and helps to classify soft tissue tumors. Therefore FISH is mandatory for the choice of therapy in these tumors. In contrast to the aforementioned, up to now, the value of FISH in solid tumors is mostly limited to pure research and contributes in this way to our understanding of tumor biology. But with the use of paraffin-embedded tissue and the first results obtained, it seems very likely that a direct correlation between histological classification and cytogenetic characteristics of solid tumors can be achieved in the near future. This information might not only provide insights into tumor biology, but could also contribute to a different tumor classification, a sort of risk estimation, where we might predict the possible biological behavior of solid tumors. This could greatly influence further therapeutic decisions thus establishing the FISH technique as an indisputable part in the diagnosis of solid tumors.

Animals↗
PubMed2006

A standard cytogenetic photomap for the mosquito Anopheles stephensi (Diptera: Culicidae): application for physical mapping.

To facilitate physical genome mapping, we have developed a new cytogenetic photomap for Anopheles stephensi (Liston) (Diptera: Culicidae), an important malaria vector in Asia. The high-resolution images of the ovarian polytene chromosomes have been straightened and divided by numbered divisions and lettered subdivisions. The exact chromosomal locations of eight DNA probes have been determined by fluorescent in situ hybridization. Using the DNA sequences, we have established correspondence between chromosomal arms among An. stephensi, Anopheles gambiae (Patton), and Anopheles funestus (Giles). The results support previous cytogenetic observations of arm translocations taking place during diversification of the species. To make the cytogenetic map useful for population genetics studies, we have indicated the chromosomal positions for the breakpoints of 19 polymorphic inversions.

Animals↗
PubMed1994

Rat tumor cytogenetics: a critical evaluation of the literature.

Cancer cytogenetics is a valuable tool for the analysis of cellular and molecular aberrations during malignant transformation and tumor progression. The rat has served as an important experimental model to investigate various steps in oncogenesis. An attempt was made to compile data on rat tumor cytogenetics from previously published data in order to provide a basis for further research, especially when combining classic and molecular cytogenetics, a yet underdeveloped area of research in rat tumorigenesis. The wealth of data presented here provides a contrast to its impact on biological specificity. Because of the different experimental procedures involved with tumor induction and the application of carcinogens at relatively high dosages, as well as occasional less than careful histological documentation, a delineation of unambiguous chromosome alterations, critical in the process of carcinogenesis, is rare in the rat. Future studies should be performed with spontaneously arising rat tumors and/or tumors after low, single-dose carcinogen exposure in order to reduce unspecific karyotype alterations not intrinsically related to tumor initiation and progression. Short-term culture or early passages in vitro should be methods of choice, especially for solid tumors, to avoid erroneous karyotype analyses because of contaminating normal cells. The combined karyological and molecular genetic approach to an analysis of tumor-specific changes, still hindered by an almost complete lack of cell type-, chromosome-, or gene-specific molecular probes for the rat, should become a focus of research in order to continue having the advantages this species offers for stage-specific analysis of tumorigenesis.

Animals↗
PubMed2002

Current developments in human molecular cytogenetic techniques.

In the last decade a variety of fluorescence in situ hybridization (FISH) assays have been developed. In this paper we present an overview on the currently available methods in molecular cytogenetics, highlighting their advantages and limitations, as well as their applications. Even though one has to be impressed by the total number of new techniques introduced in molecular cytogenetics, one has to be aware of the fact that it is not the brilliance of a technique that is important but the scientific question that can be addressed by it. In this review special emphasis has given in describing possible strategies for the characterization of marker and derivative chromosomes in tumor- and clinical cytogenetics.

Centromere↗
PubMed1996

Clinical aspects, cytogenetics and disease evolution in myelodysplastic syndromes.

Myelodysplastic syndrome (MDS) is a morphologically characterized hematologic entity that is one of the clonal myeloproliferative disorders. Approximately 50 approximately 70% of MDS patients have cytogenetic abnormalities; these are usually chromosomal deletions, but some involve translocations such as t(1;7) (q10;p10). Translocations involving chromosomal regions 3q26 or 22q11 are often therapy-related. Recent studies have demonstrated that cytogenetic changes in MDS patients have clinical relevance. Accordingly, there are now scoring systems for predicting the prognoses of MDS patients. In this review, we describe the clinical significance of cytogenetic changes in MDS. We include MDS with some atypical forms, such as MDS with hypocellular bone marrow, MDS with minimal dysplasia, and MDS with myelofibrosis.

Chromosomes, Human↗
PubMed2001

Combined study of prostatic carcinoma by classical cytogenetic analysis and comparative genomic hybridization.

Conventional cytogenetic analysis of prostatic carcinoma (PC) is characterized by inefficient growth of tumor cells during in vitro culture, leading to a lack of aberrant karyotypes in many of investigated tumors. In this study we have combined a modified short-term tissue culture method for conventional banding analysis and comparative genomic hybridization (CGH) to examine genetic changes in PC, and to evaluate the effect of the in vitro culture on chromosomal changes by comparing results of the two methods. Cytogenetic analysis was performed on 34 PCs using both, conventional and molecular methods. Tumor tissues were obtained predominantly from untreated primary tumors from 48 patients. For karyotyping all tumor samples were short-term cultured using a feeder layer technique. Additionally DNA from uncultured tumor material from 17 of those patients was isolated and screened for copy number changes using CGH. Conventional banding analysis: clonal aberrations were detected in 65% of the tumor samples. Most of the chromosomal findings were numerical changes, including loss of chromosomes Y (32%), 18, 19 and 21 (each 12%). Less frequent, trisomy of chromosome 7 and monosomy of chromosomes 9, 12 and 22 (each 9%) was found. Additionally an inversion of chromosome 9p and a deletion at chromosome 7q was found in two cases. In 35% no clonal aberrations could be detected. CGH: DNA copy number changes were detected in 65% of the analyzed tumors. Predominantly losses of DNA sequences were found. The most common losses were found at chromosome regions 13q21q33 (29%), 6q11q23 (24%), 16q, and 18 (each 18%), and the most common gains at 19 (18%). In six tumors no copy number changes were found. Both methods showed a similar aneuploidy rate, suggesting that the feeder layer technique is quite a suitable method for in vitro culture of PC cells. However, the two techniques produced substantially differing results for most of the tumor samples, and in some cases the discrepancies are quite striking. Therefore eventual culture effects need to be taken into account when comparing results from conventional cytogenetics and CGH. Some contrary findings from the two methods are discussed.

Aged↗
PubMed2026

Three-Year Experience of Cytogenetic and Molecular Genetic Evaluation in Patients With Disorders of Sex Development at a Tertiary Care Centre in Eastern India.

OBJECTIVES: Disorders of sex development (DSD) include a range of conditions in which chromosomal, gonadal, or anatomical sex deviates from the typical developmental pathway. The diagnostic approach to DSD has shifted from karyotyping to molecular genetic tools. This study evaluated the clinical presentation, cytogenetic spectrum, and diagnostic utility of conventional and advanced molecular genetic investigations in patients with suspected DSD managed at a tertiary care facility in Eastern India over a three-year period. METHODS: A retrospective observational study was conducted at the Genetics Laboratory of a tertiary care teaching hospital in Eastern India. Consecutive patients with clinically suspected DSD referred between January 2022 and December 2024 were included. Demographic and clinical data were obtained from referral records, and peripheral blood samples were analysed using standard G-banded karyotyping according to the International System for Human Cytogenomic Nomenclature (ISCN 2020). Fluorescence in situ hybridisation (FISH), chromosomal microarray analysis (CMA), and whole-genome sequencing (WGS) were selectively performed in cases with inconclusive cytogenetic findings, suspected structural chromosomal abnormalities, or complex phenotypes. RESULTS: A total of 98 suspected DSD cases were evaluated during the study period. The most frequent chromosomal constitution was 46,XY DSD (37, 37.8%), followed by 46,XX DSD (30, 30.6%) and sex chromosome DSD (21, 21.4%). Culture failure occurred in 10 (10.2%) samples. Advanced genetic techniques, including FISH, CMA, and WGS, improved diagnostic clarification in selected complex cases. CONCLUSION: This experience highlights the importance of integrating contemporary high-resolution technologies with conventional cytogenetics to enhance the assessment, counselling, and treatment of individuals with DSD.

chromosomal analysis↗
PubMed1998

[Cytogenetic changes in low grade central osteosarcomas].

Low grade central osteosarcomas are a group of rare bone neoplasms morphologically simulating benign bone tumors or tumor-like lesions (fibrous dysplasia, nonossifying fibroma, osteoblastoma, chondromyxoidfibroma or aneurysmal bone cyst). Because of the apparent bland histology they may be misinterpreted as benign lesions despite their primary low malignant behavior and late metastatic potential including the capability to transform into a highly malignant sarcoma. In contrast to high grade osteosarcomas cytogenetic studies of these entities are very rare. Karyotyping including FISH analysis with painting- and centromere-specific probes was done in 2 cases of low grade central osteosarcomas (fibrous dysplasia like type). One case was a primary lesion in the upper femur, the other was a recurrent lesion in the upper humerus. Additionally a static DNA cytometry using Feulgen stained imprints was carried out in both cases. In the first case clonal aberrations with a Robertsonian translocation between chromosomes #14 und #15, balanced translocations including chromosomes #5 and #21, #12 and #20, and a supernumary ring chromosome derived from chromosome #1 were detected in a near diploid karyotype. The second case displayed the development from a DNA-diploid to a DNA-peritetraploid lesion during a follow up of six years. Cytogenetic different marker chromosomes and again ring chromosomes were detected in a near tetraploid karyotype. Low grade central osteosarcomas of fibrous dysplasia like type may be characterized by chromosomal aberrations including ring chromosomes. Regarding the last feature these cytogenetic findings resemble those found in low grade parosteal osteosarcomas and other mesenchymal lesions of borderline behavior or low malignancy grade (for example dermatofibrosarcoma protuberans, low grade liposarcoma).

Adolescent↗
PubMed1999

Chromosomal aberrations in breast cancer: a comparison between cytogenetics and comparative genomic hybridization.

The analysis of chromosomal imbalances in solid tumors using comparative genetic hybridization (CGH) has gained much attention. A survey of the literature suggests that CGH is more sensitive in detecting copy number aberrations than is karyotyping, although careful comparisons between CGH and cytogenetics have not been performed. Here, we compared cytogenetics and CGH in 29 invasive breast cancers after converting the karyotypes into net copy number gains and losses. We found 15 tumors (56%) with a significant agreement between the two methods and 12 tumors (44%) where the methods were in disagreement (two cases failed CGH analysis). Interestingly, in 13 of the 15 tumors where the two methods were concordant, there was also a strong correlation between chromosome index and DNA index by flow cytometry. In the opposite situation, i.e., when chromosome and DNA indices were not matching, there was disagreement between cytogenetics and CGH in 10 of the 12 tumors. Of the discordant cases, all except one had a "simple" abnormal karyotype. Unresolved chromosomal aberrations (marker chromosomes, homogeneously staining regions, double minutes) could not completely explain the differences between CGH and karyotyping. A likely explanation for the discrepancies is that the methods analyzed different cell populations. Gains and losses found by CGH represented the predominant (often aneuploid) clone, whereas the abnormal, near-diploid karyotypes represented minor cell clone(s), which, for unknown reasons, had a growth advantage in vitro.

Aneuploidy↗
PubMed1999

AlphaIFN-induced hematologic and cytogenetic remission in chronic eosinophilic leukemia with t(1;5).

Chronic eosinophilic leukemia (CEL) is a myeloproliferative disease characterized by excessive eosinophilic proliferation with clonal cytogenetic abnormalities. The most frequent cytogenetic abnormality is a break in the q 31-35 region of chromosome 5, where genes encoding for IL-3, IL-5 and GM-CSF (all cytokines involved in eosinophilopoiesis) are located. We report the case of a patient with CEL with t(1;5) (q23;q31), who obtained complete hematologic and major cytogenetic response after two years of alpha-interferon (alpha-IFN) therapy. Two other cases of complete response to alpha-IFN are reported in the literature. A trial with alpha-IFN could be considered as front line treatment in this rare disease.

Adult↗
PubMed1999

[Determination of trisomy 9p by molecular cytogenetic technology].

OBJECTIVE: To use molecular cytogenetic techniques for the determination of complex chromosomal aberrations that could not be distinguished by conventional cytogenetic method. METHODS: Chromosome painting, comparative genomic hybridization (CGH) and color banding chromosome analysis (RxFISH) were used to identify a case with chromosome 9 aberration by G-banding. RESULTS: The patient has a karyotype of 46,XX,9p+ by G-banding. Both chromosomes 9 were uniformly painted, including the extra segment on one of the 9p alleles. CGH revealed a duplication of the entire 9p short arm. After analysis with RxFISH the patient's karyotype could be accurately described as 46,XX,dup9p (p11-->p24::p24-->qter). CONCLUSION: The present report shows that some late technological developments in the field of cytogenetics can facilitate the study of the diseases linked to complex chromosomal aberrations and may find significant application in basic and clinical medical studies.

Child, Preschool↗
PubMed2000

Cytogenetics as an aid in the diagnosis of lymphomas.

Multiple classifications of lymphomas are available. Generally, distinctions are made to identify low, intermediate, and high-risk groups. Histopathologic differentiation is at times difficult. The revised European-American lymphoma classification (REAL) uses histology, clusters of differentiation markers, histochemistry, and cytogenetics for definitive identification. This work reviews the karyotypic and FISH (fluorescent in situ hybridization) findings in some common lymphomas. B-Cell lymphomas, which make up approximately 85-90% of lymphomas, are associated with cytogenetic changes of +12, 13q14, 14q32, 2p11, and 22q13. Translocations help to support the diagnosis of follicular cell lymphoma t(14;18),(q32;q21), mantle cell lymphoma t(11;14)(q13;q32), and Burkitt's lymphoma t(2;8),t(8;14) and t(8;22). T-Cell lymphomas may show changes in 14q11,7p or 7q. Many of the lymphomas are characterized by complex karyotypic changes. Specific FISH probes are useful in determining characteristic or identifying marker chromosomes. Cytogenetic and FISH studies aid in the diagnosis, correct classification, and evaluation of therapy for a variety of lymphomas.

Bone Marrow Neoplasms↗
PubMed2000

Cytogenetic damage and cell-mediated immunity in pneumoconiosis.

The International Agency for Research on Cancer (IARC) determined that crystalline silica inhaled from occupational sources should be classified as carcinogenic to humans and upgraded it from group 2A to group 1. It has also been found that silicosis may be associated with cancer of various organs and with autoimmune diseases. We studied both the cytogenetic effects and the influence on cell-mediated immunity of mineral dust inhalation in patients with pneumoconiosis, including silicosis. The frequency of sister chromatid exchanges and micronucleus in the pneumoconiosis group were significantly higher than in the controls, suggesting a cytogenetic influence of the occupationally inhaled dust. Alterations in the immunoregulatory T cells were observed in the pneumoconiosis groups, suggesting that inhaled mineral dust may cause immunotoxic effects. Based on these findings, we can consider that cytogenetic damages and immunoregulatory abnormalities in pneumoconiosis patients may play a role in the pathogenesis of various cancers and autoimmune diseases associated with pneumoconiosis.

Aged↗
PubMed2000

[Cooperation between genetic counseling centers, cytogenetic laboratories and in vitro fertilization centers in the treatment of reproductive disorders].

The techniques of assisted reproduction have recently become the most effective methods of treatment of infertility; namely ICSI (intra-cytoplasmic sperm injection), MESA (microepididymal sperm aspiration), TESA (testicular sperm aspiration) and TESE (testicular sperm extraction). The techniques have been increasingly successful, even above the average efficiency of classical IVF (in vitro fertilization). It can be demonstrated by the percentage of ICSI-aided births percentage per 100% of embryotransfers in ISCARE; 1996 = 21.3%, 1997 = 26.15%, 1998 = 29.7%. The successful use of these techniques is associated with the rise of risks which result from the selection of couples for assisted reproduction with genetic-based infertility and with the rise of risks involving the introduction of genetic-based defects in to the next generation. Presently, a list of indications is being developed, which, while still not accepted officially, identifies patients for genetic counselling. Only the counselling center has the competence to estimate genetic risks over generations. Subsequently, after selection by the center, during 1997 and 1998 the chromosomes of 731 patients were cytogenetically examined, representing 429 infertile couples from the centres ISCARE, PRONATAL, FERTIMED, and CAR 1. LF UK. Within these 429 couples, belonging to four groups of indications, the cytogenetic examination was informative in 8.15%. This finding of a relatively high percentage (10 times more than in the general population) confirms the validity of the list of indications and the necessity of cooperation among the genetic counselling center, cytogenetic laboratory and the IVF centre.

Chromosome Aberrations↗
PubMed2000

Cytogenetic characterization of acute myeloid leukemia in Shwachman's syndrome. A case report.

We report on a case of acute myeloid leukemia in a 17-year old boy affected by Shwachman Diamond syndrome (SDS). Conventional cytogenetics at diagnosis revealed an abnormal clone with complex karyotypic changes including typical myeloid aberrations, such as monosomy 5, tetrasomy of chromosome 8, trisomy 9, and deletion of the short arm of chromosome 12. The boy was treated with conventional chemotherapy and reached complete remission of leukemia, confirmed by cytogenetics and fluorescence in situ hybridization. Nevertheless he failed to regenerate normal marrow cellularity and blood cell count. Cytogenetic information on hematologic malignancies in SDS patients are discussed.

Abnormalities, Multiple↗
PubMed2000

[Methods in molecular cytogenetics for determination of prognostically important chromosome changes in patients with chronic lymphatic leukemias].

BACKGROUND: We applied classical cytogenetics, FISH and CGH to investigate prognostic important chromosomal changes, deletions of 17p, 11q and trisomy of chromosome 12 in 90 B-CLL patients at the time of diagnosis. METHODS AND RESULTS: Using classical cytogenetics the chromosomal changes were detected in 17 (18%) patients. Trisomy 12 was found in three patients, deletion 11q in two patients and deletion 17p in four patients. The employment of FISH and CGH revealed chromosomal changes in 52 (58%) patients, the trisomy of chromosome 12 was detected in 12 (13%) patients, the deletions of 11q and deletions of 17p in 10 patients (11%). Statistically significant correlation between higher disease activity and the stage of disease and the presence of deletion 11q and 17p was found. The trisomy of chromosome 12 was found in patients with abnormal markers and in patients with higher stage of the disease. CONCLUSIONS: According to our results, the majority of chromosomal abnormalities in B-CLL may escape detection when classical cytogenetics is the only diagnostic technique used. It stresses the importance of employing additional techniques including FISH and CGH at the time of diagnosis.

Adult↗