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J M García-Sagredo

Publications and source records attributed to J M García-Sagredo.

At least 19 recordsLinked to original sources
PubMed2000

Trisomy/ tetrasomy of chromosome 8 and +i(8q) as the sole chromosome abnormality in three adult patients with myelomonocytic leukemia.

We report three cases of tetrasomy 8 associated with myeloid disease. Two patients had chronic myelomonocytic leukemia (CMMoL) and the other had acute monocytic leukemia (AML M5 FAB). Two patients had trisomy/tetrasomy chromosome 8 as the sole abnormality. The other patient with CMMoL had two normal 8 chromosomes plus one isochromosome 8q; this is the first case of long arm chromosome 8 tetrasomy without short arm 8 monosomy. This cytogenetic finding suggests the importance of the genes located in the long arms of chromosome 8.

Adult↗
PubMed1998

Automated FISH spot counting in interphase nuclei: statistical validation and data correction.

The evaluation of an automated system for Fluorescence In Situ Hybridization (FISH) spot counting in interphase nuclei is presented in this paper. Different types of experiments have been performed with samples from known populations. In all of them the goal is to detect mosaicism of chromosome X in leukocytes from mixtures in known proportions of healthy male and female blood. First the initial results from the automatic FISH analysis system were obtained and evaluated. Then the analysis was modified to reduce systematic errors, so that the results are closer to what an experienced human operator would have obtained (system calibration step). Finally, an additional control probe of chromosome Y was used to detect and discard cells where incorrect hybridization or other abnormal situations had occurred. In each step the system sensitivity was determined by the use of two statistical validation tests, so that the improvement brought about by the correction methods could be assessed. The results obtained in the study showed that, using both corrections, the system is able to detect 10% monosomies with a significance level alpha = 0.1%.

Algorithms↗
PubMed1997

Applying watershed algorithms to the segmentation of clustered nuclei.

Cluster division is a critical issue in fluorescence microscopy-based analytical cytology when preparation protocols do not provide appropriate separation of objects. Overlooking clustered nuclei and analyzing only isolated nuclei may dramatically increase analysis time or affect the statistical validation of the results. Automatic segmentation of clustered nuclei requires the implementation of specific image segmentation tools. Most algorithms are inspired by one of the two following strategies: 1) cluster division by the detection of internuclei gradients; or 2) division by definition of domains of influence (geometrical approach). Both strategies lead to completely different implementations, and usually algorithms based on a single view strategy fail to correctly segment most clustered nuclei, or perform well just for a specific type of sample. An algorithm based on morphological watersheds has been implemented and tested on the segmentation of microscopic nuclei clusters. This algorithm provides a tool that can be used for the implementation of both gradient- and domain-based algorithms, and, more importantly, for the implementation of mixed (gradient- and shape-based) algorithms. Using this algorithm, almost 90% of the test clusters were correctly segmented in peripheral blood and bone marrow preparations. The algorithm was valid for both types of samples, using the appropriate markers and transformations.

Algorithms↗
PubMed1996

Cytogenetic study of neuroendocrine carcinoma of Merkel cells.

We describe the cytogenetic study of a neuroendocrine tumor of Merkel cells which appeared in a patient following a heart transplant. An abnormal karyotype was observed in a metastatic lymph node. The abnormality includes two markers derived from the long arm of chromosome 1, while maintaining two normal chromosomes 1.

Aneuploidy↗
PubMed1995

Frequency and characteristics of familial aggregation of Paget's disease of bone.

The cause of Paget's disease of bone (PDB) is unknown. In an attempt to ascertain the proportion of familial cases and evaluate the influence of genetic factors on the occurrence of the disease, a study was undertaken based on 35 PDB patients from our Unit. Their families were investigated, with the participation of a total of 128 first-degree relatives. Fourteen (40%) of these 35 index cases had at least one other first-degree relative affected with PDB and were defined as "familial." The remaining 21 (60%) were considered "sporadic." The frequency of males in the familial cases (79%) was significantly higher than among the sporadics (29%; p < or = 0.01). Mean age at diagnosis (63.1 +/- 12.6 vs. 71.3 +/- 8.7; p < or = 0.02), proportion of polyostotic cases (85.7% vs. 52.4%, p < or = 0.05), and mean number of involved bones per patient (4.36 +/- 2.50 vs. 2.33 +/- 1.93, p < or = 0.01) differ significantly in the familial and sporadic groups. The disease appears to be transmitted via both paternal and maternal sides, and pedigree analysis suggested an autosomal dominant inheritance or multifactorial mechanism. Apart from green-and-blue eye color, which was clearly associated with familial grouping (OR 6.25, 95% CI 1.15-37.16, p < or = 0.01), crude analysis on several genetically based traits and environmental variables revealed no other significant differences between the groups. The adjusted odds ratio estimated for green-and-blue eye color was 2.92 (95% CI 0.38-22.74).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Interstitial del(12)(q15q22) in myelodysplastic syndromes.

A patient with a myelodysplastic syndrome and a 12q deletion was studied and followed-up. After 10 years and several cytogenetic studies, it is suggested that this abnormality can be the sole chromosomal change in myelodysplastic syndromes.

Anemia, Refractory, with Excess of Blasts↗
PubMed1994

Automatic scoring of sister chromatid exchanges by image analysis in a dose response experiment.

A system which automatically selects second division metaphases and then, automatically scores the number of SCEs of each cell is described. In an initial set of experiments, the performance of the components of the system was measured using a data set in which metaphases had been visually classified as either 2nd division or other; and in 2nd division metaphases, every SCE had been marked on a hard copy. SCE scoring had a true positive rate of about 75% and a false positive rate of about 1.5 false SCEs per metaphase analyzed. Second division detection had a true positive rate of 80% and a false positive rate of about 10% of the non-2nd division cells. Next, the overall system was compared to human visual scoring in a dose-response experiment by analyzing the effect of mitomycin C on human chromosomes scored visually by two observers and by the fully automatic scoring. Human visual scoring and machine analysis showed similar dose responses, but the variability between them was considerable.

Cell Division↗
PubMed1994

Chromosomal disorder and neoplastic diseases in a family with inherited fragile 16. Causality or casualty?

We describe a family with an inherited fragile chromosome 16 with the concurrence of a constitutional chromosome abnormality, together with neoplastic pathology within the family. The following findings should be pointed out: in relation to the constitutional chromosome pathology, of the proband's 3 children, the eldest daughter was a carrier of the fragile 16, the same as the father, and the second child, a son, had Down syndrome (trisomy 21). Regarding the tumoral pathology of this family, one of the proband's daughters died in childhood from acute lymphoblastic leukemia, whereas the proband developed two different malignant hematologic disorders: a follicular lymphoma and an acute nonlymphocytic leukemia (M5 type). Moreover, two independent acquired chromosome disorders coexisted in the proband; each of these was related to one of the respective hematologic disorders.

Aged↗
PubMed1994

Burkitt lymphoma with a duplication of der(8)t(2;8). Interpretation of a complex karyotype by chromosome painting.

A 51-year-old male patient was diagnosed with Burkitt lymphoma 3 months after cardiac transplantation. The bone marrow karyotype was very complex, and to better define the complex karyotype we used the in situ suppression hybridization technique. Previously we interpreted this karyotype to be: 48,XY,t(2;8)(p11;q24), +der(2)t(2;8)(p11;q24),del(2)(q23), +7, +der(8)t(2;8)(p11;q24), +12, -13, -18, by G banding techniques, with a duplication of the t(2;8) derivatives. After in situ hybridization we changed to a: 48,XY,t(2;8)(p11;q24),t(2;18)(q23;q22), +7, +der(8)t(2;8)(p11;q24), +12, -13, which implies duplication of only one t(2;8) derivative.

Burkitt Lymphoma↗
PubMed1992

Ph-positive chronic myeloid leukemia with t(8;21)(q22;q22) in blastic crisis.

A patient diagnosed with chronic myeloid leukemia was studied periodically during his illness. The result showed the presence of a Philadelphia (Ph) chromosome by a 9;22 translocation as a single abnormality to the time of blastic crisis. At that time, the chromosome studies showed a clonal evolution. Furthermore, a second derivated line was added to the Ph line. This new anomaly consisted of a 8;21 translocation, considered as specific of M2 type acute nonlymphoblastic leukemia of French-American-British classification.

Adult↗
PubMed1992

[Use of a chromosome 21 gene library in the identification of a marker chromosome in chronic myeloid leukemia].

The non-isotopic in situ hybridization makes it possible the analysis of, both, numeric and structural chromosome aberrations in interphase nuclei. Moreover, this technique is useful for identification of chromosome markers of unknown origin, frequently present in malignant diseases. In our case, the fluorescent in situ hybridization allowed us, in a CML patient in accelerated phase, to know the origin of a chromosome marker, and then, to state that the patient had a 21 trisomy added to the Philadelphia chromosome.

Blast Crisis↗
PubMed1991

Unusual translocations and other changes in acute leukemia.

We report three cases of ANLL and one case of ALL in which we found chromosome abnormalities not previously described. The first patient had a (9;11;16)(p22;q23;p13) translocation in the relapse after bone marrow transplantation. In the second case, a secondary leukemia following a Wilms' tumor, there was a single chromosome anomaly, an inversion of chromosome 13. The third case also presented an isochromosome 13q. In the fourth patient we observed a translocation between two achrocentric chromosomes, as in the third patient, but not of the Robertsonian type: t(21;21)(q22.1;q22.5).

Adolescent↗