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M R Caballin

Publications and source records attributed to M R Caballin.

16 recordsLinked to original sources
PubMed2006

Analysis of gamma-rays induced chromosome aberrations: a fingerprint evaluation with a combination of pan-centromeric and pan-telomeric probes.

PURPOSE: To evaluate the types of induced chromosome aberrations after the exposure of peripheral blood to gamma-rays by the simultaneous detection of all centromeres and telomeres; and to analyse the suitability of different radiation fingerprints for the assessment of radiation quality in cases of recent exposures. MATERIAL AND METHODS: Peripheral blood samples were irradiated at 2, 4 and 6 Gy of gamma-rays. Cytogenetic analysis was carried out by fluorescence in situ hybridization (FISH) technique with pan-centromeric and peptide nucleic acid (PNA)-telomeric DNA probes. Cells were analysed using a Cytovision FISH workstation, chromosome aberrations and the length of the acentric fragments were recorded. RESULTS: The total number of the incomplete chromosome elements was 276. The ratio between incomplete elements and multicentrics was 0.38. The number of acentrics was 1096, 71% were complete acentrics, 15% incomplete acentrics, and 14% interstitial fragments. The relative length of complete, incomplete and interstitial acentrics fragments were 2.70 +/- 0.04, 1.91 +/- 0.07, and 1.42 +/- 0.04 respectively. The mean value of the F-ratio was 11.5 higher than the one, 5.5, previously obtained for alpha-particles. For the G-ratio there was no difference between gamma-rays and alpha-particles, 2.8 and 2.8 respectively. The mean value of the H-ratio for gamma-rays, 0.25, was lower than for alpha-particles 0.40. CONCLUSION: The results support that the percentage of incomplete chromosome aberrations depends on radiation type; low-linear energy transfer (LET) radiation would produces less incomplete aberrations than high-LET radiation. The F- and H-ratios seem to be good indicators of radiation quality, although a real estimation of the H-ratio is only possible using pan-telomeric probes.

Adult↗
PubMed2005

Translocation yields in peripheral blood lymphocytes from control populations.

PURPOSE: To record the latest information on control levels of translocations in cultured human lymphocytes. MATERIALS AND METHODS: Control-level data from seven European laboratories that are using fluorescence in situ hybridization (FISH) techniques for retrospective biological dosimetry have been combined in a meta-analysis. After correction for the differing probe combinations used, tests of consistency are performed. The combined data have been used to test for individual variation, systematic variation with age, gender and smoking habits. RESULTS: There is a strong variation of translocation yield with age but no variation was detectable with gender or smoking habits. After correction for age, homogeneity tests showed that about 10% of individuals were outside the 95% confidence limits as opposed to 5% expected. From a total of 385, there is an excess of about 20 individuals most of whom have an unexpectedly high yield of translocations. CONCLUSIONS: For retrospective biological dosimetry purposes a generic age-dependent control level can be assumed. No other lifestyle factors such as smoking appear to have a significant effect on translocation yield.

Adolescent↗
PubMed2005

Review of translocations detected by FISH for retrospective biological dosimetry applications.

Several European laboratories have combined their research efforts to arrive at a consensus view on using fluorescence in situ hybridisation (FISH) for retrospective dosimetry. The aim of this review is to report these views and to highlight some areas where further work is needed. Translocations in the stable cells should be measured only in the cells that contain the full complement of the painted material. Two-way and one-way translocations should be combined with equal weight. The control level of translocations has a strong dependence on age, which has now been measured and the system has been calibrated. In conclusion, the technique works and a lifetime dose to the bone marrow from low-linear energy transfer radiation of 0.5 Gy above normal background levels can be measured for any individual. The main application is considered to provide an independent verification of lifetime doses to individuals who might form a part of an epidemiological study.

Calibration↗
PubMed2004

A cytogenetic follow-up of some highly irradiated victims of the Chernobyl accident.

A follow-up of 10 highly irradiated men, mostly reactor crew, from the Chernobyl accident is described. Their pre-accident medical conditions and relevant medical status approximately 10-13 y later are listed. A comparison is made between estimates of their average whole-body penetrating radiation doses derived from several biological parameters. First estimates were based on their presenting severity of prodromal sickness, early changes in blood cell counts and dicentric chromosome aberrations in lymphocytes. In three cases ESR measurements on tooth enamel were also made. Retrospective dosimetry using FISH translocations was attempted 10-13 y later. This showed good agreement for those patients with the lower earlier dose estimates, up to about 3 Gy. For the others, extending up to about 12 Gy, the translocations indicated lower values, suggesting that in these cases translocations had somewhat declined. Repeated chromosomal examinations during the follow-up period showed an expected decline in dicentric frequencies. The pattern of decline was bi-phasic with a more rapid first phase, with a half-life of approximately 4 months followed by a slower decline with half-lives around 2-4 y. The rapid phase persisted for a longer time in those patients who had received the highest doses. 10-13 y later dicentric levels were still above normal background, but well below the translocation frequencies.

Adult↗
PubMed2004

Analysis of alpha-particle induced chromosome aberrations in human lymphocytes, using pan-centromeric and pan-telomeric probes.

PURPOSE: The aim of the present study has been the evaluation of the incomplete chromosome aberrations induced after alpha-particle irradiation by the simultaneous detection of all centromeres and telomeres present in human lymphocytes. Moreover, a study on the lengths of the different acentric fragments is presented. MATERIALS AND METHODS: Attached lymphocytes were irradiated at doses of 0.2, 0.5, 0.7 and 1 Gy using a 241Am source. Flourescent in-situ hybridization (FISH) techniques were applied using pan-centromeric and pan-telomeric probes. All abnormal cells were digitalised and analysed using a Cytovision FISH workstation. The description of all abnormalities observed, and the length of the acentric fragments was recorded. RESULTS: A total of 378 incomplete chromosomes plus incomplete acentrics was found. Cases with more than 92 telomeres were not detected. The ratio between total incomplete elements and multicentrics was 1.00. The total number of acentric (ace) fragments was 822; 57% of them were complete fragments ace (+,+), 26% incomplete fragments ace (+,-), and 17% interstitial fragments ace(-,-); the mean relative lengths were 2.91 +/- 0.06, 1.91 +/- 0.07 and 1.63 +/- 0.07, respectively. In all three cases a secondary peak in the length distribution was found, corresponding to a relative length between 3.5 and 4. CONCLUSION: The percentage of incomplete rejoinings is higher after alpha-particle exposure than that described previously for low-linear energy transfer (LET) radiation exposures. The results seem to indicate that compared to low-LET radiation, after alpha-particle exposure centromere-containing elements are more likely to be repaired.Many interstitial fragments are large linear forms that cannot be considered as non-distinguishable acentric rings.

Alpha Particles↗
PubMed2003

Prenatal detection of rare chromosomal autosomal abnormalities in Europe.

The aim of the present study was to evaluate the prenatal detection of rare chromosomal autosomal abnormalities by ultrasound (US) examination. Data were obtained from 19 congenital malformation registries from 11 European countries, between 01/07/96 and 31/12/98. A total of 664,340 births were covered and 7,758 cases with congenital malformations were recorded. Rare autosomal abnormalities were diagnosed in 114 cases (6.6%) from a total of 1,738 chromosome abnormalities. There were a wide variety of autosomal abnormalities: the most common were deletions (33 cases), duplications (32 cases), trisomies of chromosomes 8, 9, 10, 14, 15, and 16 (23 cases), and unbalanced rearrangements (19 cases). Out of these cases, 45.6% were detected prenatally by US examination due to the presence of congenital anomaly. As for the types of chromosomal anomaly, unbalanced rearrangements and deletions were the most frequently detected by US. A high percentage of cases with balanced rearrangements were associated with severe congenital anomalies. The most frequent congenital anomalies detected by US were cystic hygroma (20.6%), central nervous system defects (17.6%), cardiac defects (13.2%), and diaphragm defects (10.3%). This large series offers useful information about prenatal diagnosis by US of congenital defects associated with rare autosomal abnormalities and it provides a valuable knowledge about outcome. Fetal anomalies detected by US that were associated with rare autosomal abnormalities were significantly more frequent than those associated with common chromosomal abnormalities (45.6 vs. 34.7%). This study indicates the need to increase the detection of congenital anomalies by US.

Chromosome Aberrations↗
PubMed1998

Clinical, morphological, cytogenetic and molecular aspects of a series of Ph-negative chronic myeloid leukemias.

Clinical, morphological, cytogenetic and molecular (fluorescence in situ hybridization and RT-PCR) data were analyzed in twelve Philadelphia negative chronic myeloid leukemias (Ph-negative CMLs). Four patients were classified as BCR-positive. A standard b2a2 or b3a2 transcript was found, and the BCR-ABL hybrid gene was located on the 22q11 band in three cases and on the 1p35 band in one case with a t(1;9)(p35;q34). All were classified as typical chronic granulocytic leukemia (CGL) according to the French-American-British (FAB) morphological guidelines. Responses to therapy were evaluated by FISH in the four patients, and proved to be poorer than in Ph-positive CMLs. Eight BCR-negative patients were identified. They could be characterized by an older age, a less proliferative form of disease than the BCR-positive patients, and a frequent (six out of eight) abnormal karyotype. The FAB classification identified four CGLs and four atypical CMLs (aCML). A normal karyotype was more frequent in the patients classified as CGL whereas all the aCMLs had a chromosomal abnormality. Three patients had chromatin clumping and this morphologic feature was associated with trisomy 8 in two. No correlation between the cytogenetic, morphologic and the clinical data were found. Five patients had poor tolerance to therapy with a frequent occurrence of bone marrow failure and hemorragic syndrome, whereas three patients responded to a standard treatment of CML. Our study reinforces previous data on Ph-negative BCR-positive CMLs and emphasizes the difficulty in correlating clinical, morphologic, cytogenetic data in Ph-negative BCR-negative CMLs. However, our data also argue in favor of the existence of true Ph-negative BCR-negative CMLs and suggest that some of them can respond to a standard treatment of CML.

Adult↗
PubMed1997

Location of the BCR-ABL fusion gene on the 9q34 band in two cases of Ph-positive chronic myeloid leukemia.

Two new variant Philadelphia (Ph) chromosomes with an aberrant location of the BCR-ABL fusion gene on 9q34 of the derivative 9 are reported. One presented cytogenetically as a standard t(9;22)(q34;q11), whereas the other was classified as an ins(9;22)(q34;q11.1q11.2) using the combined interpretation of cytogenic, FISH, and molecular data. The mechanisms of the two rearrangements are presented. It is suggested that the insertion has occurred in a single event in the patient with ins(9;22). In the patient with t(9;22), both a translocation and an insertion, occurring either sequentially or simultaneously, can account for the location of the BCR-ABL fusion gene on the derivative 9. A possible poor prognostic impact of this aberrant location of the BCR-ABL is also suggested by the clinical data reported in such patients.

Aged↗
PubMed1992

Cytogenetic studies in 112 cases of untreated myelodysplastic syndromes.

Cytogenetic studies were performed in 112 untreated cases of myelodysplastic syndrome (MDS) between 1985 and 1990. Among 112 patients who were examined at the time of diagnosis, 54 had an abnormal karyotype (48%). The highest frequency of chromosome abnormalities was observed in refractory anemia with excess of blasts (RAEB) and RAEB in transformation (RAEB-t) and the lowest in refractory anemia with ring sideroblasts (RARS) and chronic myelomonocytic leukemia (CMMoL). Numerical changes were observed in 19 cases and structural in 17; chromosome 8 was most frequently gained (11 cases), whereas chromosome 7 was most frequently lost (6 cases), 5q- in 14 (4 as a sole anomaly); involvement of 7q22 was seen in 3 cases, 11p in 2 patients, 11q in 3 (one patient as a sole anomaly), 12p in 4 (2 patients as a sole anomaly), i(17q) in 4 (3 patients as a sole anomaly), and complex chromosomal defects in 10 patients. If one takes into account the prognosis value, a complex karyotype and the presence of ring chromosomes were correlated with the worst prognosis, followed by -7/7q-; an intermediate prognosis corresponds to i(17q), 12p as a sole anomaly, +8 (as a sole anomaly or plus other anomalies), and involvement of 12p. Patients with a 5q- as a sole anomaly or with a normal karyotype, had the best prognosis.

Adolescent↗
PubMed1990

Trisomy 7 may be a primary change in noninvasive transitional cell carcinoma of the bladder.

We describe two cases of transitional cell carcinoma of the bladder associated with trisomy 7. In one of them, trisomy 7 was the only chromosome abnormality observed. In the second case, trisomy 7 was found in 25 (80.6%) of the metaphases; in two of them this was the only anomaly, while in three metaphases trisomy 8 was also present, and in other two trisomy 10 was also observed. Our results suggest that trisomy 7 could be a primary change in TCC, and a review of the literature indicates that when it is present as the sole karyotypic abnormality is may be associated with a non-invasive behavior of the tumor.

Aged↗
PubMed1990

Centromere splitting in bladder cancer.

Cytogenetic studies on a bladder carcinoma, carried out using short time cultures, showed centromere splitting (CS) mainly affecting chromosomes 22, 13, 14, 21, 15, 20, 12, 7, 17, and 18. Clonal trisomies and monosomies were also detected. Our case is the first description of CS in bladder tumor cells. Our results suggest that CS is an early phenomenon in the karyotypic evolution of this case; it can be considered a primary, yet unspecific, chromosome change related to aneuploidy in bladder cancer.

Aneuploidy↗
PubMed1990

Cytogenetic study of a patient with the Sézary syndrome.

A cytogenetic study was performed in a patient with Sézary syndrome, which is a T-helper lymphoproliferative disorder. Metaphases were obtained from a phytohemagglutinin-stimulated lymphocyte culture. Normal, hypodiploid (42 to 45 chromosomes) and hypotetraploid (84 to 88 chromosomes) cells were observed. Both abnormal cell lines showed the same abnormalities involving chromosomes 1, 2, 4, 6, 10, 11, 12, 14, 16, and 20.

Aged↗
PubMed1988

Human sperm chromosomes.

Sperm chromosome studies have been performed in 70 normal males. The incidence of aneuploidy in this group is approximately 3-4%, and that of structural anomalies close to 5%. In carriers of reciprocal or Robertsonian translocations, the results are extremely variable, with percentages of unbalanced sperm from 8 to 87%. No unbalanced spermatozoa have been observed in patients with pericentric or paracentric inversions. In cancer patients treated with radio and/or chemotherapy, the incidence of chromosome abnormalities is much higher, and significantly different from that found in controls.

Aneuploidy↗
PubMed1987

Expression of a possible constitutional "hot spot" in sperm chromosomes of a patient treated for Wilms' tumor.

Sperm chromosomes were studied in a man who was treated for Wilms' tumor with radiotherapy (RT) and chemotherapy (CT) 18 years ago. Human pronuclear sperm chromosomes were obtained after penetration of zona-free hamster eggs. Eighty-nine sperm chromosome complements were analyzed; 12.4% of them showed structural anomalies. This percentage was statistically different from the one found in our laboratory for controls (p less than 0.05). Five of eleven structurally abnormal metaphases had the same aberration: fission of chromosome #1 with the breakpoint at or near the centromere. Breaks and rearrangements of chromosome #1, often involving the centromere region, are among the most frequent anomalies found in Wilms' tumor cells.

Adult↗
PubMed1977

Trisomy 20 mosaicism.

The first known case of trisomy 20 mosaicism is described. As in other cases of (partial) trisomy 20, the patient showed scarce physical malformations. It is suggested that trisomies for chromosomes of the F group are rare not because they are lethal but as a result of the morphology of the chromosomes involved.

Chromosomes, Human, 19-20↗