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Biomedical subjects

I Slavutsky

Publications and source records attributed to I Slavutsky.

At least 19 recordsLinked to original sources

Intron 22 factor VIII gene inversions in Argentine families with severe haemophilia A.

Intron 22 factor VIII gene inversion (Inv22) is the most common mutation causing severe haemophilia A (SHA). We studied Inv22 in 34 SHA affected families by Southern blotting. Data from the familial history of the disease and the inhibitor status were also included. We found Inv22 in 41 % of SHA Argentine families (35 % with type 1 and 6 % with type 2), in close agreement with previously reported series. No significant correlation between the inheritance (familiar or sporadic disease) and the presence of inversions was found. Our population showed 24 % of families included at least one hemophiliac with inhibitor. In families positive for Inv22, 29 % of patients developed inhibitor but this increased frequency was not statistically significant. In conclusion, analysis of Inv22 in SHA patients should be used as a first line method because it provides useful and secure information for carrier detection and prenatal diagnosis in a high percentage of cases.

Argentina

Spontaneous breakage and fragile site expression in chronic lymphocytic leukemia.

It has been suggested that genetic predisposition to cancer might be related to spontaneous chromosome instability or to fragile site expression. Therefore, spontaneous breakage and fragile sites were analyzed in nine untreated chronic lymphocytic leukemia (CLL) patients to determine their relation to cancer rearrangements. Five cases presented spontaneous gaps and breaks with a random distribution of breakpoints. In cultures treated with fluorodeoxyuridine or aphidicolin, 29 specific bands could be defined as fragile sites. A significant clustering of these sites was found with known common fragile sites (c-fra) and cancer breakpoints described in the literature. Most of these cancer breakpoints were involved in structural abnormalities associated with CLL (p < 0.00001). These data suggest that the expression of specific fragile sites might be related to structural chromosomal aberrations in CLL.

Aged

Cytogenetic characterization of an extra structurally abnormal chromosome associated with severe mental retardation: inv dup (15) (q13).

We have studied an extra structually abnormal chromosome (ESAC) in a 13 years old boy with profound mental, psychomotor and speech retardation, behavioral problems, seizures and abnormal electroencephalogram. The examination of the bisatellited ESAC with chromosome banding demonstrated that the karyotype was: 47, XY, +inv dup (15) (pter-->q13::q13-->pter). The cytogenetic characterization of the inv dup (15) is reported with special emphasis on the usefulness of DA/DAPI staining when G-banding is sequentially performed to discard possible heteromorphisms in DA/DAPI positive chromosomes, and the importance of Ag-NOR heteromorphisms to ascertain the maternal origin of the inv dup (15). A U-type exchange between two non-sister chromatids is proposed as its mechanism of formation. The clinical features of the case were consistent with those previously reported in similar cases.

Adolescent

Age related decrease of NOR activity in bone marrow metaphase chromosomes from healthy individuals.

AIMS: To present data obtained from human bone marrow preparations from healthy individual showing that the proportion of metaphases with silver stained nucleolar organiser region (AgNOR) chromosomes is associated with the age of the donor. METHODS: Bone marrow preparations from eight Russian and 10 Argentinian healthy individuals donating bone marrow for heterologous transplantation were studied by silver staining. The Russian bone marrow preparations were used directly, while the bone marrow specimens from Argentinian donors were incubated for 24 hours at 37 degrees C in F-10 medium with 15% fetal bovine serum. The slides were silver stained by the one step method of Howell and Black with slight modifications. Thirty metaphases with clearly defined D and G group chromosomes were scored for the numbers of AgNORs. All metaphases that were adjacent to silver stained interphase nuclei were analysed to assess the percentage of AgNOR positive mitoses. The Kruskal Wallis test and Kendall's rank correlation coefficient (rK) were used to assess the relation between age and the percentage of AgNOR positive cells. RESULTS: The mean numbers (SE) of AgNORs per metaphase were 5.06 (0.17) and 5.56 (0.23) for the Russian and Argentinian groups, respectively, with no significant differences between the two groups. The common percentage of AgNOR positive cells decreased significantly as a function of age, with an rK = -0.57 (p < 0.0012). CONCLUSIONS: The percentages of AgNOR negative metaphases in bone marrow from healthy individuals is strongly associated with age and this may be related to age related telomere loss.

Adolescent

The human breast cancer cell line IIB-BR-G has amplified c-myc and c-fos oncogenes in vitro and is spontaneously metastatic in vivo.

IIB-BR-G is an undifferentiated, highly heterogeneous, hormone receptor negative human breast cancer cell line previously established in our laboratory from a patient's primary tumor. An in vitro growing cell line (IIB-BR-G) and a xenotransplanted tumor growing in nude mice (IIB-BR-G(NUDE)) were derived. To further characterize these systems, immunocytochemical analysis was performed for differentiation antigens (PEM 200 kDa, CEA, NCA 90 kDa), blood-group related antigens (Le(x), sTn), oncogenes and tumor suppressor gene products (Her-2/neu protein, p53), metastasis-related cathepsin D and CD63/5.01 Ag, and the chemokine monocyte chemotactic protein 1 (MCP-1). Expression of markers was heterogeneous in these different systems. Previously reported karyotypic analysis has shown extensive chromosomal alterations including double min. Searching for oncogene amplification, we detected augmented copy number of c-myc and c-fos, the last one with two rearranged fragments. No amplification was found for c-erbB-2 in the cell line or in IIB-BR-G(NUDE), although this oncogene was amplified in the patient's primary tumor DNA. The differences observed between the patient's tumor, the cell line and the IIB-BR-G(NUDE) tumors are probably due to clonal expansion of cell variants not present in the original tumor. Electron microscopy of IIB-BR-G growing cells revealed epithelial characteristics with abundant dense granules, presumably secretory, distributed all over the cytoplasm and great nuclear pleomorphism. In vitro, IIB-BR-G cells showed a significant number of invading cells by Matrigel assay. After nearly 40 sequential subcutaneous passages of the original xenograft through nude mice, 80% of recipients developed spontaneous metastases, primarily to the lung and lymph nodes. Since this experimental model allowed to analyze changes produced in cancer cells from the primary tumor during adaptation to in vitro and in vivo growth, our results provide novel insights on the behaviour of hormone independent metastatic breast cancer.

Animals

Vinorelbine: cell cycle kinetics and differential sensitivity of human lymphocyte subpopulations.

Antiproliferative activity induced by vinorelbine (VRB) was studied in whole blood cultures (WBC) and in lymphocyte subpopulations evaluated by the MAC (morphology-antibody-chromosome) method. In WBC a significant delay in cell cycle kinetics in VRB-treated cultures compared with controls (P < 0.001) was observed. The highest dose (1.0 microg/ml) arrested all cells at the first metaphase. Both WBC and isolated lymphocyte cultures showed a significant increase in the mitotic index (MI) in VRB-treated cultures compared with controls (P < 0.001). Moreover, a significant increase in the MI was found in VRB-treated CD4 cells compared with VRB-treated CD8 (P < 0.01) and B-lymphocytes (P < 0.001).

Adult

[Large granular lymphocytic leukemia. Case report with scarce expression in peripheral blood].

The case of a 33 year old woman with a large granular lymphocytic leukemia is presented. The main symptoms were neutropenia and recurrent respiratory bacterial infections. No enlargement of the liver, spleen or lymph nodes was noted. Circulating lymphocytes averaged 3000/microliter with 35% of large granular cells. The bone marrow biopsy showed lymphatic infiltration with both nodular and interstitial pattern. Lymphocytes bore the T suppressor phenotype (CD8+, CD45 RO+, CD20-, kappa-, lambda-). Cytogenetic studies revealed a low expression clone with 7q-: del (7)(q36). Gene rearrangements for immunoglobulins or T-cell receptors could not be demonstrated by Southern Blot. Bone marrow cultures grew normally while both normal and patient bone marrow showed marked inhibition when incubated with patients serum. Normalization of the peripheral granulocytic count was obtained with prednisone, while granulocytic-stimulating factors, chlorambucil, and cyclosporine A were partially active or inactive. We suggest that this case represents a form of the lymphoproliferative disease of granular lymphocytes. To our knowledge, the deletion of the long arm of chromosome 7 has not been described in this disease.

Adult

Chromosome instability in untreated adult celiac disease patients.

Spontaneous chromosome aberrations (CAs) and induced fragile sites (FSs) were analysed in 12 untreated adult coeliac disease (CD) patients and 8 healthy controls. Blood lymphocytes from each individual were cultured for 72 h at 37 degrees C in F-10 medium with 5% fetal calf serum and 0.1 ml phytohemagglutinine. FSs were induced by FudR (10 micrograms/ml, 24 h before harvesting) and caffeine (2.2 mM. 6 h before harvest). Spontaneous CAs and FSs were analysed on 30-50 Giemsa-stained and G-banded metaphases. The mean frequencies of spontaneous CAs (abnormal cells, gaps/cell and breaks/cell) of CD patients (0.24 +/- 0.02, 0.21 +/- 0.02 and 0.13 +/- 0.02, respectively) were significantly higher than those of controls (0.04 +/- 0.01, 0.02 +/- 0.01 and 0.02 +/- 0.01, respectively) (p < 0.001). Fourteen spontaneous CAs and 5 FSs specific for CD patients presented a strong coincidence (70%) with bands involved in T- and B-cell malignant lymphoma rearrangements. These findings suggest that CD has chromosome instability affecting specific points that could be related to the high prevalence of malignancies in this disorder.

Adolescent

Variant (8;22) translocation in lymphoblastic lymphoma.

Occasional cases with the chromosomal translocations that juxtapose the c-myc oncogene to Ig genes have been reported in large cell, small lymphocytic, immunoblastic, and follicular lymphomas. In this report, we present a 20 year-old female with lymphoblastic lymphoma of B-cell type and a translocation t(8;22), in which cytogenetic, immunologic, and molecular studies were performed. To the best of our knowledge this is the first report of this association.

Adult

Molecular study of the interferon genes in chronic myeloid leukemia.

The interferons alpha, beta, and w (IFNA, IFNB, IFNW), are a family of genes that have been mapped on the short arm of chromosome 9 (9p21-22). Deletions of genetic material on 9p are frequently observed in hematological diseases, particularly in lymphoid neoplasias. In this paper we have performed the molecular studies of IFNA and IFNB genes in chronic myeloid leukemia (CML) in order to determine if the deletions of these genes are prevalent in this pathology. Forty CML patients, Philadelphia positive or with BCR/ABL rearrangement, were studied at diagnosis. The analysis of IFNA and IFNB genes was performed by Southern and dot blot techniques. Homozygous or hemizygous deletions of IFNA and IFNB genes could not be detected, indicating that deletions of these genes would not be present or would be a very infrequent event in the chronic phase of the CML patients.

Adult

Micronuclei induction by carboplatin in human lymphocyte subpopulations.

Micronuclei (MN) induction by carboplatin, cis-diammine-1,1-cyclobutane decarboxylate platinum (II) (CBDCA), in B and T lymphocytes was studied by the MAC (morphology/antibody/chromosome) method which allows the immunologic identification of different cell lineages. An increased frequency of MN in B and T lymphocytes in CBDCA-treated cultures compared with controls was observed (p < 0.001). CBD cells were found to be more sensitive to CBDCA damage. CBDCA-treated cultures showed a decrease, albeit statistically non-significant, in the proportion of CBD interphasic and mitotic cells. Furthermore, higher MN frequencies in isolated lymphocytes than in whole blood in both control and CBDCA-treated cultures were observed.

Adult

Biologic, immunocytochemical, and cytogenetic characterization of two new human melanoma cell lines: IIB-MEL-LES and IIB-MEL-IAN.

Two human melanoma cell lines, derived from metastases of two patients with epithelioid malignant amelanotic melanomas, and designated IIB-MEL-LES and IIB-MEL-IAN, have been established. Both cell lines have been in continuous culture over 2 years and were propagated continuously for 85 and 75 serial passages, respectively. Morphologically, IIB-MEL-LES is composed predominantly of spindle shaped cells, whereas IIB-MEL-IAN grows as a monolayer of cuboid and stellate shaped cells with many rounded cells in suspension. Immunocytochemical studies revealed that both cell lines express S-100 protein, vimentin, and GD3 and GD2 gangliosides but are negative for keratin and collagen. Both cell lines express HLA class I and HLA-DR antigens in variable proportions. The MAGE-1 gene is expressed only by the IIB-MEL-IAN cell line, as revealed by PCR analysis. Cytogenetic analysis of both cell lines revealed abnormal karyotypes; the modal chromosome numbers of IIB-MEL-LES and IIB-MEL-IAN were 48 and 81, respectively. IIB-MEL-LES cells presented rearrangements in chromosomes 1, 14 and X, gains in chromosomes 10, 20, and 21 losses in chromosomes 15 and Y. The most frequent markers observed in IIB-MEL-IAN cells were 7q+, 10p+, 2p+, i(6p), 2q+, and 10q-. Clonal gains were observed in chromosomes 12 and 21, whereas losses were seen in chromosomes 1, 2, 3, 4, 6, 7, 11, and 17. Both cell lines were capable of forming colonies in soft agar and developed tumors when transplanted into nude mice, reproducing and maintaining the characteristics of the original tumors. These cell lines and their xenografts appear to provide useful systems for studying the biology, genetics and histogenesis of human malignant melanoma and could be utilized for the development of melanoma vaccines.

Adult

AZT-induction of micronuclei in human lymphocyte subpopulations.

Micronucleus (MN) induction by azidothymidine (AZT) in B and T lymphocytes was analyzed by a recently developed MAC (morphology-antibody-chromosome) method which allows the immunologic identification of different cell lineages. An increased frequency of MN in AZT-treated cultures compared with controls was observed. CD4 cells were found to be more sensitive to AZT damage. AZT-treated cultures showed a significant decrease in the proportion of CD4 interphasic cells. Furthermore, higher MN frequencies in isolated lymphocytes than in whole blood in both control and AZT-treated cultures were observed.

Adult

Increased rDNA transcriptional activity in celiac disease.

The activity of nucleolar organizer regions (NORs) in chromosomes of peripheral blood lymphocyte cultures from 20 healthy subjects and 32 patients with celiac disease (CD) (nine untreated patients, nine treated but with dietary lapses, and 14 treated with gluten-free diet (GFD) and normal small bowel histology) was studied. Furthermore, three female patients diagnosed with small bowel non-Hodgkin's lymphoma (NHL) complicating CD were studied. Silver (Ag)-staining technique was used to visualize positive NORs. In each individual, 20 metaphases were analyzed to determine the number of NORs per cell. The average of Ag-NOR+ per cell, expressed as mean +/- SD, was found to be higher in the CD group (6.62 +/- 0.65) compared with controls (5.70 +/- 0.81) (p less than 0.001). This increase was evident in both groups of chromosomes analyzed (D and G). No differences were found among the three groups, but all of them were found to be statistically different compared to controls (p less than 0.001). The NHL complicating CD patients showed a statistically increased frequency of Ag-NORs (7.20 +/- 0.39) with respect to CD patients (p less than 0.02) and controls (p less than 0.001). These findings show an increase of the transcriptional activity of rDNA in CD that could be related to the high incidence of malignancy in this pathology. Longitudinal studies of CD patients should be performed to confirm this evidence.

Adolescent

Description of a new human breast cancer cell line, IIB-BR-G, established from a primary undifferentiated tumor.

The establishment of a new human breast cancer cell line (IIB-BR-G) was successful after a previous growth of the cells isolated from a breast primary tumor in a female nude mouse. The IIB-BR-G cell line and the primary tumor do not express estrogen or progesterone receptors. Vimentin and keratin expression were found in the cell line and in the nude mouse tumor. This cell line displays high morphological heterogeneity with atypical multinucleated megacells, and it is capable of anchorage-independent growth and tumor formation in nude mice. The cytogenetic analysis confirmed its human origin and revealed multiple marker chromosomes and extensive chromosomal alterations including rearrangements, gains, losses, isochromosomes, and double minutes (DMs).

Animals

Ag-NOR staining and satellite association in lymphoproliferative disorders.

The nucleolar organizer regions (NORs) activity and the frequency of satellite associations (SA) in peripheral blood lymphocytes from patients with two chronic lymphoproliferative disorders were studied: 10 cases with B-cell chronic lymphocytic leukemia (B-CLL) and 10 with mycosis fungoides (MF). Thirteen healthy individuals formed the MF control group, and the oldest 7 constituted the B-CLL control group. The mean of Ag-NORs per metaphase was increased in B-CLL patients (8.80 +/- 0.63) compared with their controls (7.99 +/- 0.90) (P less than 0.025), meanwhile MF patients' value did not differ from their controls. In both disorders, the frequency of Ag-NORs in the G chromosomes was increased. The analysis of SA in B-CLL patients only revealed an increase in the frequency of cells with more than 4 ASPs (association pairs). Meanwhile, a significant higher mean of ASPs per cell in MF patients (1.74 +/- 0.41) compared to controls (1.40 +/- 0.24) (P less than 0.05) was observed. Furthermore, a close correlation between cells with complexes of 3 or more chromosomes and the mean of ASPs per cell was also found in MF. In conclusion, an increase of the Ag-NORs expression in B-CLL patients and a modification in the degree of SA in MF patients were found.

Adult