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A Amiel

Publications and source records attributed to A Amiel.

At least 19 recordsLinked to original sources
PubMed2001

Comparative genomic hybridization in polycythemia vera and essential thrombocytosis patients.

Polycythemia vera (PV) and essential thrombocytosis (ET) are clonal chronic myeloproliferative disorders originating from a multipotent stem cell. Bone marrow examinations reveal chromosomal abnormalities in 15-43% of PV patients and 5% of ET patients, but no specific recurring abnormality has been found to date. We aimed to find cytogenetic aberrations in PV and ET by comparative genomic hybridization (CGH), a relatively new molecular cytogenetic technique. In this study, CGH analysis was performed on peripheral blood leukocytes of 12 PV patients and 8 ET patients. One patient (8.3%) with PV had an abnormal karyotype with a deletion in 7q11.2 and one patient with ET (12.5%) had a gain in 18p. Peripheral blood analysis by CGH revealed a low frequency of cytogenetic abnormalities in PV and ET patients. However, using CGH we were able to detect two cytogenetic aberrations that were not reported previously in these disorders.

Aged↗
PubMed2001

Fetal cells in the uterine cervix: a source for early non-invasive prenatal diagnosis.

Various non-invasive techniques for prenatal diagnosis have been under investigation. We evaluated the success of fetal sexing using a non-invasive technique for obtaining fetal cells, uterine cervix brushing, in combination with FISH. Thirty pregnant women who completed between 6 and 10 weeks of gestation and who were scheduled to undergo pregnancy termination were included in the study. A Pap smear cytobrush was inserted through the external os to a maximum depth of 2 cm and removed while rotating it a full turn. The material that was caught on the brush was spread on four microscope slides. Two-color FISH was used for fetal sexing. Following pregnancy termination, a placental sample was used for full karyotyping. In 29/30 cases FISH diagnosis was confirmed by chromosomal analysis. The only male case in which a Y chromosome was not seen was from a pregnancy of 6 weeks 6 days gestational age. One case was mosaic of 46,XY/47,XXY (25%). In most cases (7/13) the Y chromosome was already identified in the first analyzed slide. With the use of a cytobrush fetal cells can be easily obtained for the purpose of prenatal diagnosis of chromosomal disorders.

Cervix Uteri↗
PubMed2001

Interchromosomal effect leading to an increase in aneuploidy in sperm nuclei in a man heterozygous for pericentric inversion (inv 9) and C-heterochromatin.

We describe a man with pericentric inversion 9 and constitutive heterochromatin, and a high disomy rate in his sperm cells (with all probes analyzed). The disomy rate was estimated with the following probes: 8, 9, 18, X, and Y, and was significantly higher than that in control sperm cells, while chromosome 9 showed the highest disomy frequency. The probes of X and Y together showed the same disomy frequency as X and Y alone, which indicates the same nondisjunction rate in the first meiotic division. We suggest that the interchromosomal effect found in this man differed from other findings in sperm cells of men carrying an inversion in terms of the difference in the length of the heterochromatin between the two chromosomes 9. Also, it is well known that the effect of inversion 9 with increased heterochromatin is highly variable and may even vary in members of the same family.

Abortion, Spontaneous↗
PubMed2001

The influence of cytogenetic aberrations on gene replication in chronic lymphocytic leukemia patients.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in humans, with the major cytogenetic aberrations of trisomy 12 and deletion of 13q14. This study examined the influence of these aberrations on general gene replication. The study group included three subgroups: (1) 15 CLL patients, (2) 4 CLL patients with trisomy 12, (3) 3 CLL patients with deletions in 13q14. Five healthy individuals served as a control group. Monocolor fluorescence in situ hybridization (FISH) with probes for c-myc, HER-2/neu, and p53 was applied to lymphocyte nuclei for the evaluation of replication timing. Asynchronous replication (SD) rate was significantly higher in all CLL patients (P < 0.01) when compared to the control group and was even higher in the group of CLL patients with trisomy 12 and 13q14 deletion (P < 0.01). The asynchrony rate was significantly higher in cells with trisomy 12 for all three probes analyzed, compared to "healthy" cells in the same patients (P < 0.001). To conclude, in CLL patients with a chromosomal aberration such as trisomy 12 and 13q14 deletion we were able to demonstrate a high rate of asynchrony of replication. The high correlation between cells with trisomy 12 and SD pattern could reflect direct influence of the aberration on gene replication and cell cycle control.

Aged↗
PubMed2001

Modified order of allelic replication in lymphoma patients at different disease stages.

Asynchronous replication of homologous loci was reported in lymphocytes of patients with lymphoma, ovarian and renal cancer as well as in lymphocytes of patients with premalignant conditions, for example, essential mixed cryoglobulinemia associated with hepatitis C virus and in monoclonal gammopathy of unknown significance. In the present study we evaluated the replication pattern in lymphocytes of four groups of patients with intermediate grade of non-Hodgkin lymphoma at various stages of their disease: 1) at diagnosis; 2) during cytotoxic treatment; 3) in remission; and 4) in relapse. A significantly higher proportion of the asynchronous pattern of replication at diagnosis, during cytotoxic treatment, and in relapse was noted as compared to healthy controls and to patients who achieved remission of their lymphoma. Also, the frequency of the two doublets (DD) pattern in every group studied was significantly lower than in the controls. If our findings can be confirmed in larger, long-term prospective studies, it may allow the use of a simple and inexpensive tool to closely observe patients with lymphoma who are at high risk for relapse.

Aged↗
PubMed2000

Bcl-2 rearrangement in patients with chronic hepatitis C associated with essential mixed cryoglobulinemia type II.

Hepatitis C virus (HCV) infection is found in 80% to 90% of patients with essential mixed cryoglobulinemia (EMC) type II, which is associated with monoclonal IgMk produced by monoclonal B cells. It was investigated whether bcl-2 rearrangement is associated with the clonal B-cell proliferation of EMC induced by hepatitis C. The study groups were composed of 15 patients with HCV and EMC, 12 patients with HCV without EMC, and 7 patients with chronic liver disease (CLD) unrelated to HCV. Fluorescence in situ hybridization with probes was applied to JH and to bcl-2 to study whether JH/bcl-2 translocation was present in these patients. Thirteen of 15 (86%) of patients with HCV-related EMC had the JH/bcl-2 translocation, a significantly higher rate than in HCV patients without EMC (16%; P < .001). Bcl-2 rearrangement was not detected in the patients with CLD not related to HCV. The JH/bcl-2 translocation may constitute a pathogenetic link for the development of NHL in patients with HCV infection. (Blood. 2000;96:2910-2912)

Adult↗
PubMed2000

Complete hydatidiform mole and a coexistent viable fetus: report of two cases and review of the literature.

OBJECTIVE: The aim of this study was to report the clinical features, management, and outcome of two cases of complete hydatidiform mole with a coexisting viable fetus and to review the literature. PATIENTS: In this article, we report on the well-documented follow-up of 2 cases of twin pregnancies with complete hydatidiform mole and a viable fetus, both of which ended with the delivery of a normal infant at 41 and 26 weeks of gestation. It is of interest that both pregnancies were achieved following induction of ovulation with hMG/hCG. Since 1977, the year in which complete and partial moles were characterized as distinct pathologic entities, 15 cases (including our 2) have been reported. RESULTS: Persistent GTT developed in eight patients (53.3%) and four patients (27.7%) developed metastatic disease. Seventy-five percent patients with persistent GTT were treated with single-agent chemotherapy. The median gestational age of the patients with subsequent persistent GTT was 34.5 weeks compared to 38 weeks in the patients without persistent GTT. CONCLUSION: Complete hydatidiform mole and coexistent fetus is a rare occurrence and is associated with an increased risk of persistent gestational trophoblastic tumor. Based on currently available information, it seems that in the presence of a stable pregnancy, normal karyotype, and a normal sonogram it is reasonable to allow the pregnancy to continue.

Adult↗
PubMed2000

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Journal Article↗
PubMed2000

Multiple myeloma: monoallelic deletions of the tumor suppressor genes TP53 and RB1 in long-term follow-up.

Recently, a working-model of a stepwise malignant transformation in the molecular pathogenesis of multiple myeloma (MM) was proposed, involving the tumor suppressor gene TP53 and retinoblastoma gene (RB1) as prominent components of cell cycle control. To further define the role of TP53 and RB1 in disease progression, we retrospectively analyzed by fluorescence in situ hybridization (FISH) cytological material from 16 patients who underwent sequential bone marrow biopsies during the course of their disease. For TP53, no deletions were detected at presentation or during follow-up. It is possible that the patients reported here represent a subset with relatively long survival, and therefore did not demonstrate the TP53 deletions that had been reported in patients with a very poor prognosis. For RB1, monoallelic deletion was demonstrated in nine patients. In each case, the deletion appeared already in the first biopsy analyzed. The presence of a deletion did not affect the rate of tumor progression or the length of follow-up, and thus prognosis. Monoallelic deletions of RB1 appear to be a frequent and early event in the pathogenesis of MM, without obvious relevance for disease progression.

Aged↗
PubMed2000

Replication status as a marker for predisposition for lymphoma in patients with chronic hepatitis C with and without cryoglobulinemia.

OBJECTIVE: Essential mixed cryoglobulinemia (EMC) type II is associated with hepatitis C virus (HCV) in 90% of the patients with this disorder. A significant subset of these patients is at risk to develop non-Hodgkin lymphoma (NHL). The objective of this study was to examine whether the presence of EMC, a presumably premalignant step of lymphoproliferation, is associated with changes in the replication state of normal structural genes. MATERIALS AND METHODS: The study group included three subgroups: (1) seven patients with HCV without EMC; (2) eight patients with HCV associated with EMC. 3. Seven patients with follicular lymphoma; and (3) six healthy individuals served as control group. Monocolor fluorescent in situ hybridization (FISH) with probes to p53, RB-1, and 21q22 was applied to leukocytes nuclei for the evaluation of replication timing. RESULTS: Asynchronous replication (SD) rate was similar in patients with NHL and those with HCV associated with EMC and both are significantly higher when compared to patients with HCV without EMC and to normal controls (p < 0.01) for each comparison. This held true for all studied loci (21q22, RB-1, and p53). Patients infected by HCV (but without EMC) had a significantly higher rate of asynchronous pattern in comparison with healthy controls (p < 0.01). CONCLUSIONS: Patients with a "premalignant" clinical condition HCV with EMC already demonstrate asynchronous type of replication which is similar to patients who already have an established malignant disease (i.e., NHL). In the future, replication may be used to assess the risk of malignant transformation in patients with "benign" proliferation.

Adult↗
PubMed2000

Replication asynchrony increases in women at risk for aneuploid offspring.

We attempted to demonstrate a relation between a loss of replication control, centromere dysfunction, and predisposition to non-disjunction. Couples with a Down syndrome offspring were the high-risk probands. One-color FISH (fluorescent in-situ hybridization) was applied to interphase nuclei (lymphocytes). Replication pattern of two pairs of alleles, RB-1 and 21q22, were studied, and the rate of aneuploidy was estimated using two alpha-satellite probes of chromosomes 8 and 18. Our results suggest the existence of an association between replication timing and the rate of non-disjunction. A higher rate of allele asynchrony and aneuploidy was found in older women and in mothers of a Down syndrome offspring. These findings may reflect a predisposition for meiotic non-disjunction in these women.

Adult↗
PubMed1999

Deletion of 6q27 in chronic lymphocytic leukemia and multiple myeloma detected by fluorescence in situ hybridization.

Nonrandom deletions of the long arm of chromosome 6 (6q) are associated with various lymphoid malignancies. It has been suggested that deletions of 6q25-27, 6q21, and 6q23 typically occur in intermediate-grade, high-grade, and low-grade lymphomas, respectively. We used fluorescence in situ hybridization (FISH) to evaluate the occurrence of 6q27 deletion in chronic lymphatic leukemia (CLL) and multiple myeloma (MM). 6q27 deletion was detected in 21% of patients with CLL and in 28% of patients with MM. The percentage of cells containing deletions ranged between 25-49. Two patients with MM had progressive disease and the aberration was detected in both. We conclude that FISH is a sensitive method to detect 6q27 deletion in lymphoproliferative disorders. Also, this deletion is not specific to intermediate-grade lymphomas, but occurs also in CLL and MM.

Aged↗
PubMed1999

Replication pattern in cancer: asynchronous replication in multiple myeloma and in monoclonal gammopathy.

In this study we evaluated the replication pattern and cell-cycle dynamics of cells from patients considered to have a premalignant condition (monoclonal gammopathy, or MGUS) and patients with multiple myeloma (MM), as well as healthy controls. We applied the fluorescence in situ hybridization (FISH) technique with the TP53, RB-1 and 21q22 loci on the patient's cells. Asynchrony was determined by the presence of one single and one set of double dots in the same cell. The rate of asynchronic replication was significantly higher in the cells from MM patients, with intermediate value in the cells from MGUS, while the lowest rate was in cells from controls. We suggest that these results may reflect the changes in gene replication and cell-cycle progression that occur in premalignant and malignant cells.

Aged↗
PubMed1999

Deletion 5q31 in patients with stable, melphalan-treated multiple myeloma.

The risk of myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML) in patients with multiple myeloma has been estimated to be 10-20% after 10 years. Most myeloma patients develop MDS/AML after 3-4 years of treatment with alkylating agents, mainly melphalan; chromosomes 5 and 7 are most frequently involved. We studied 14 patients with myeloma by fluorescence in situ hybridization (FISH) with a probe to 5q31 (the critical area of deletion on chromosome 5) to verify whether deletion of 5q31 occurs during the course of stable, uncomplicated myeloma, and to assess the clinical importance of this abnormality. We found 2 patients (14%) with deletion of 5q31 in 30-40% of their peripheral white blood cells. One patient with this deletion received a high cumulative amount of melphalan, and the other patient was treated with multiple alkylating agents, including melphalan. In these patients, no clinical or laboratory evidence of transformation occurred 14 and 12 months after the finding of the aberration. These findings suggest that 5q-may occur months prior to the overt development of (t)-MDS/AML, and raise important concerns regarding the management of patients with this and similar aberrations, including modification of treatment and performance of cytogenetic evaluation prior to autologous or PSC transplantation. The clinical and biological implications of these findings should be evaluated in larger clinical and laboratory studies.

Aged↗
PubMed1998

Replication pattern of the p53 and 21q22 loci in the premalignant and malignant stages of carcinoma of the cervix.

BACKGROUND: Loss of replication synchrony during the S-phase of the cell cycle has been shown to be associated with aneuploidy in malignant cells. METHODS: The replication pattern of cervical cells obtained from normal patients and from patients with preinvasive and invasive carcinoma of the cervix was evaluated. The fluorescence in situ hybridization technique was applied to Papanicolaou smear slides using p53 and 21q22 loci. Asynchrony was determined by the presence of one single and one set of double dots in the same cell. RESULTS: The rate of asynchrony in low grade squamous intraepithelial lesions was not significantly different from that of normal controls. However, the rate of asynchrony was significantly higher in the high grade squamous intraepithelial lesions and even higher in the invasive carcinoma. CONCLUSIONS: The authors believe these results reflect impairment of the replication control of homologous loci and that this phenomenon may be correlated to the phenotype of the tumor.

Chromosomes, Human, Pair 21↗
PubMed1998

Dilemma of trisomy 20 mosaicism detected prenatally: is it an innocent finding?

The clinical significance of mosaicism trisomy 20 detected prenatally following amniocentesis remains uncertain, due to the rarity of liveborn cases with inconsistent clinical findings, the short postnatal follow-up, and failure in evaluating other fetal tissues for the presence of the trisomy. We report on a 15 month-old 46,XX chromosome constitution in white blood cells, while skin fibroblasts demonstrated trisomy 20 mosaicism (54%) by fluorescence in situ hybridization (FISH) analysis. Clinical examination of the baby showed only minor phenotypic signs (bilateral epicanthal folds, delayed closure of fontanel with no other gross anomalies), but demonstrated a considerable developmental delay in gross and fine motor skills along with hypotonicity. This is the second oldest described liveborn with trisomy 20 mosaicism confirmed in skin fibroblasts. This cytogenetic aberration along with her developmental delay suggests that the two findings are related and that aberration affects various fetal tissues and is not confined to extra-embryonic tissue as suggested previously. Yet, an undiagnosed condition may be the cause of the child's developmental delay. Based on this case and following a review of the literature we suggest that when mosaic trisomy 20 is identified in amniocytes, further evaluation is required. Cord blood should be analyzed preferably by FISH. During counseling the parents should be advised of an additional risk, such as developmental delay, even when fetal cord karyotype and detailed ultrasonic scan are normal.

Chromosomes, Human, Pair 20↗
PubMed1998

Temporal differences in replication timing of homologous loci in malignant cells derived from CML and lymphoma patients.

A close association usually exists between replication timing of a given locus and its transcriptional activity: expressed loci replicate early whereas silent ones replicate late. Accordingly, alleles that show concomitant expression replicate synchronously, while those displaying an allele-specific mode of expression show temporal differences in their replication timing, i.e., they replicate asynchronously. We aimed in our study to see whether the cancer phenotype is accompanied by a relaxation in the temporal control of allelic replication. Fluorescence in situ hybridization (FISH) was used to determine the level of synchronization in replication timing of four pairs of homologous loci in samples of malignant cells derived from patients with chronic myeloid leukemia (CML) and lymphoma and in samples from healthy individuals. Four loci, HER2 mapped to 17q11.2-q12, a locus at 21q22, TP53 mapped to 17q13.1, and MYC mapped to 8q24 were studied. In each sample we analyzed two chromosomal regions, either 17q11.2-q12 and 21q22 or 17p13.1 and 8q24. The results showed distinct differences between healthy individuals and CML/lymphoma patients: all samples derived from noncancerous subjects showed high levels of synchrony in replication timing of alleles, whereas those of cancer patients displayed a large temporal difference in replication timing, indicating early and late replicating alleles. Thus, as judged by four unrelated loci, malignancy is associated with changes in the replication pattern of homologous loci.

Alleles↗