Biomedical subjects

A Amiel

Publications and source records attributed to A Amiel.

At least 19 recordsLinked to original sources

PubMed2003

Application of comparative genomic hybridization technique for detection of chromosomal aberrations in benign cystic teratoma.

Benign cystic teratoma, also known as dermoid cyst, is the most common of all ovarian neoplasms accounting for 10%-20% of all ovarian cysts. Most have a normal 46,XX karyotype. Less than 2% can undergo malignant transformation. By using the comparative genomic hybridization technique on nine benign ovarian cysts we were able to show two cases with chromosomal aberrations not seen before in dermoid cysts but known to be involved in malignant ovarian tumors. We speculate that these are the tumors carrying the potential for malignant transformation.

Adult↗

PubMed2003

Application of comparative genomic hybridization in search for genetic aberrations in fibroadenomas of the breast.

We applied a comparative genomic hybridization (CGH) technique to paraffin-embedded tissue samples taken from fibroadenomas, benign breast tumors, to detect possible numerical and unbalanced genetic changes. We compared the results to those from previous cytogenetic studies of fibroadenomas. In concurrence with previous cytogenetic studies of fibroadenomas, we detected genetic aberrations in chromosomes 4-6, 8-13, 16, 18, 19, 20, and 22. In addition, with the CGH technique we were able to find two new aberrations, 15q+ and 16p-. Because these aberrations have also been reported to be present in breast cancer, the importance of this finding is yet to be determined.

Adolescent↗

PubMed2003

Molecular cytogenetic parameters in Ewing sarcoma.

To evaluate possible genomic instability and possible random aneuploidy, we applied comparative genomic hybridization and fluorescence in situ techniques, and evaluated telomerase activity in 16 cases of Ewing sarcoma (EWS) and compared the results to 7 controls. Common secondary aberrations (gains of chromosomes 8 and 12) were found in the study group. There was a direct correlation between the detection of random aneuploidy and development of tumor relapse (P = 0.0047). Other detectable abnormal parameters (secondary) and high telomerase activity were also more common among the cases with relapse but did not reach a statistical significance (probably because of the small sample size). In EWS, the detection of random aneuploidy seems to be a sensitive parameter in the prediction of tumor relapse.

Adolescent↗

PubMed2003

The effect of chlorambucil treatment on cytogenetic parameters in chronic lymphocytic leukemia patients.

The most common treatment of chronic lymphocytic leukemia (CLL) is the alkylating agent chlorambucil (CLB), with or without prednisone. In the present study, our aim was to evaluate whether treatment with CLB for more than one year induced genetic changes manifested by comparative genomic hybridization (CGH) as new chromosomal aberrations. We also studied whether CLB affected the pattern of replication by using fluorescence in situ hybridization (FISH). We found a similar rate of asynchronous pattern of replication in both treated and untreated patients with CLL. Most of the aberrations found with CGH were previously reported in CLL. More prognostically unfavorable aberrations and more cases with genetic changes were found in the treated group. The changes found were not typical of the secondary genetic aberrations associated with alkylating agents. Thus, we conclude that treatment of CLL with CLB for at least a year does not affect the parameters analyzed in this study. Longer studies are needed to further explore the effects of alkylating agents on normal and malignant cells.

Aged↗

PubMed2003

Low maternal serum concentrations of human chorionic gonadotropin as part of the triple test screening: a follow-up study.

OBJECTIVE: To determine whether low maternal serum concentrations of human chorionic gonadotropin (hCG) were associated with poor pregnancy outcome. METHODS: Between 1999 and 2000, 20,880 women underwent triple test screening in our hospital. The levels of hCG were detected by fluorescent immunoassay. Low hCG levels (< or = 0.20 MoM in our center) were considered to be a marker for increased risk for trisomy 18 or adverse pregnancy outcome. Each patient completed a questionnaire regarding fetal karyotype, complications of pregnancy and pregnancy outcome. RESULTS: Low maternal serum concentrations of hCG were detected in 119 pregnancies (0.57%). Of these, 19 (16%) were found to be missed abortions. The distribution of the remaining 100 cases was as follows: 72% had an isolated low hCG level, 24% had a low hCG level and a combination of hCG + alpha-fetoprotein < 0.80 MoM, and 4% had a low hCG level and a combination of hCG + unconjugated estriol < 0.80 MoM. No trisomy 18 or other chromosomal abnormalities were detected in our patient population. However, there were perinatal complications. CONCLUSION: Based on our screened population, a combination of multiple analytes seemed to be a better marker than an isolated finding of low maternal serum concentrations of hCG with regards to abnormal fetal karyotype, specifically trisomy 18, although it did determine a high-risk group in terms of complications of pregnancy.

Chorionic Gonadotropin↗

PubMed2002

A negative second trimester triple test and absence of specific ultrasonographic markers may decrease the need for genetic amniocentesis in advanced maternal age by 60%.

OBJECTIVE: A study was conducted to evaluate the sensitivity of combining a second trimester triple test and targeted ultrasound in order to detect Down syndrome in women undergoing amniocentesis over 35 years of age. METHODS: Women over 35 years of age underwent a triple test and an ultrasound examination for chromosomal markers immediately prior to genetic amniocentesis. RESULTS: One thousand and six women were examined. Four hundred and thirty seven were triple test-positive and in 195 cases ultrasonographic abnormalities were observed. Thirteen had Down syndrome and eight had other chromosomal abnormalities. All women with Down syndrome babies were triple test-positive and seven also had ultrasonographic markers. Three of eight women who had babies with chromosomal aberrations other then Down syndrome were also triple test-positive. CONCLUSIONS: The use of the triple test as a screening tool in our population would reduce the number of amniocenteses by 60%, while no cases of Down syndrome would be missed. Ultrasonographic markers have added little to this population. Three non-Down syndrome chromosomal abnormalities and two Down syndrome mosaic cases would be missed by this approach.

Adult↗

PubMed2002

CGH in the detection of confined placental mosaicism (CPM) in placentas of abnormal pregnancies.

Comparative genomic hybridization (CGH) was applied to samples taken from various sites of placentas originating from complicated pregnancies: 24 with intrauterine growth restriction (IUGR), one with multiple fetal malformation, one with toxemia, one with hydrocephalus and two with undetectable maternal serum alpha-fetoprotein (MSAFP). One of the most common aberrations in the IUGR cases was the addition of a whole or part of the X chromosome. Other aberrations such as additional Y chromosome or of 13(q22) or loss of chromosome 17 also appeared in different cases. In one IUGR case trisomy 8 (in one site) and 47,XXY (in all sites) were detected. In the two cases with undetectable MSAFP monosomy 16 was found. Some of the results were also confirmed by the FISH technique. In all the control cases (six normal and five with aneuploidy) CGH concurred with the known karyotype. Our results demonstrate the usefulness of the CGH technique in the genetic evaluation of fresh and paraffin embedded placentas in problematic pregnancies even when morphology is normal. However, it is very important to take multiple samples from different sites of the placenta.

Adult↗

PubMed2002

Familial lethal skeletal dysplasia with cloverleaf skull and multiple anomalies of brain, eye, face and heart: a new autosomal recessive multiple congenital anomalies syndrome.

We report on a 'new' lethal familial short-limb bone dysplasia associated with multiple anomalies in three sibs born to Arabic-Muslim consanguineous healthy parents. Clinical abnormalities included short limbs and short hands, cloverleaf skull, frontal bossing, wide anterior fontanel, hypertelorism, bilateral microphthalmia, cataract, low-set ears, narrow chest, ambiguous genitalia, cardiac ventricular septal defect (VSD) and agenesis of the corpus callosum. Radiological abnormalities included cloverleaf skull, hypoplastic clavicles and scapulae, thin, wavy cupped ribs, flat vertebral bodies with coronal clefting and several unossified vertebral pedicles and hypo-ossification of the pubic bone. The main changes noted in the long bones consisted of short-bowed long bones with abnormal metaphyses and unossified epiphyses. Chondro-osseous morphology documented degenerating chondrocytes with disorganization of the hypertrophied cartilage and short disorganized columns of hypertrophied areas. An autosomal recessive mode of inheritance seems most likely.

Abnormalities, Multiple↗

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

Acrocentric centromere organization within the chromocenter of the human sperm nucleus.

It has recently been reported that in human sperm cells, the centromeres are clustered in a chromocenter in the interior region of the nucleus. The aim of the present study was to determine the intra-chromocenter organization of the five centromeres of the acrocentric chromosomes responsible for the biosynthesis of rRNA. The acrocentric centromeres were labeled by fluorescence in situ hybridization (FISH) after mild decondensation of the sperm nuclei to preserve the tail structure. The tail was used as a topographical marker for the orientation of the nucleus. The following results were obtained: (a) the association among the five centromeres was higher than expected from random distribution; (b) all the centromeres observed were randomly located within the chromocenter, occupying about 87% of the total area of the internal nucleus; (c) a major subpopulation of centromeres was located in a preferred area occupying 8.3% of the total nuclear area, with a peak 0.6 microm on the lateral axis and 1.0 microm on the apical side of the longitudinal axis; and (d) The dispersion of the centromeres was not influenced by the degree of the nuclear decondensation. We conclude that in human sperm nuclei, the acrocentric centromeres are organized within a nonlocalized structural element in the chromocenter. The chromocenter can range from an expanded size of 87% of the whole nucleus to a preferred size of 8.3% independent of the degree of nuclear decondensation. These findings have important implications for nuclear function (rRNA) that is not directly related to sperm cell function or early embryo development.

Cell Nucleus↗

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↗

PubMed2001

Analysis of chromosomal aberrations in large hepatocellular carcinomas by comparative genomic hybridization.

Hepatocellular carcinoma (HCC) is a very common and highly malignant tumor, associated mainly with chronic viral hepatitis, cirrhosis of any cause, aflatoxin exposure and ethanol consumption. The aim of this study was to map genomic aberrations in HCC by a recently developed technique: comparative genomic hybridization (CGH). We applied CGH on 17 liver specimens, of which seven were HCCs. The rest were benign liver tumors, cirrhotic and normal livers, and other liver malignancies. Our study included mainly large tumors (mean size 10.5 cm) unrelated to viral hepatitis or cirrhosis. Our CGH analysis detected genomic imbalances in 42% of HCCs. The common aberrations included DNA gains of 1q, 9p, and 8q and DNA losses of 17p, 13q, 9q, 4q, and 11q. Also, we detected trisomies 8, 9, 18 and 21, which have not been reported previously. Gains and losses of DNA found in this study probably involve oncogenes and tumor suppressor genes that play a role in the puzzle of hepatocarcinogenesis. This study also suggests a possible link between the size of the tumor and the burden of genetic changes.

Adult↗

PubMed2001

Replication status as a possible marker for genomic instability in cells originating from genotypes with balanced rearrangements.

Most allelic pairs of DNA replicate synchronously during the S phase of the cell cycle. However, some genes frequently replicate asynchronously, i.e. genes on the X chromosome and imprinted genes. Earlier studies demonstrated an asynchronous pattern of replication in some precancerous and invasive squamous carcinoma of the cervix as well as in multiple myeloma. A high rate of asynchronous pattern was found in: (1) lymphocytes of individuals with solid tumors as well as in other malignancies; (2) amniocytes of genotypes with an extra chromosome 13, 18 and 21; (3) lymphocytes of young mothers of a Down syndrome pregnancy. The asynchronic pattern was not locus specific and was found in all loci analyzed. These findings suggested that the mechanism controlling the temporal order of replication could be altered in cells with a genetic predisposition to cancer or aneuploidy. In this study, we found a higher rate of asynchronous pattern in genotypes carrying inversions 2 and 9 and in balanced heritable translocations (p < 0.01) and an even higher rate in cases with a de-novo balanced translocation. The process of tumorigenesis may begin with a change in cell cycle regulation which includes the duplication, replication and segregation of genetic information. However, it remains unknown whether individuals with balanced chromosome rearrangements are at increased risk of developing cancer later in life.

Alleles↗

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↗