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Biomedical subjects

R Miró

Publications and source records attributed to R Miró.

At least 73 records · Page 4Linked to original sources
PubMed1989

Expression of folate-sensitive fragile sites in lymphocyte chromosomes.

The expression of folate-sensitive fragile sites (FS) was analyzed using MTX as a fragility inducer in seven normal subjects [four unrelated persons and three members of one family (father, mother, and son)]; a woman heterozygous for fra Xq27.3 with a 47,XXX karyotype; and her son, affected by the fra-X syndrome. The mean expression of chromosome lesions (CL) other than Xq27.3 was 70.1% (686CL in 978 metaphases), and the coincidence between CL and FS was 68.9%. We propose six new c-fra sites: bands 4q33 and 11q22 because they were found in two members of the same family; band 13q32 because it had a frequency of expression of 3% of metaphases; and bands 3p13, 8q21, and Xq21 because they were observed in four of the nine individuals studied.

Adult↗
PubMed1989

Cytogenetic effects of radiotherapy. Breakpoint distribution in induced chromosome aberrations.

A total of 660 breakpoints were identified in the chromosome aberrations detected in lymphocytes from cancer patients after radiotherapy. The results show that chromosomes 1, 3, and 7 were significantly more affected than other chromosomes by ionizing radiation in vivo. Chromosome arms 1p, 1q, 7q, and 11p were also significantly more affected. Some bands also showed a special sensitivity to radiation, and band 1q32 was the most affected. This band is proposed as a "hot point" for the clastogenic effect of ionizing radiation. A significant clustering of breakpoints in G bands was also found, especially at the telomeres, as previously described by other authors. Clustering of breakpoints was also observed in bands where fragile sites, protooncogenes, breakpoints involved in chromosomal cancer rearrangements, and breakpoints involved in chromosomal evolution of the Hominoidea are located.

Adult↗
PubMed1987

Fragile sites, chromosome evolution, and human neoplasia.

In a study of the possible relationship between human fragile sites, chromosomal rearrangements related to neoplasia, and chromosome regions involved in evolutionary changes, we have found that 17 fragile sites related to cancer, 15 fragile sites not related to cancer, and 17 non-fragile regions also related to human malignancy correspond or are close to bands involved in rearrangements that have taken place during chromosomal evolution in primates.

Animals↗
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↗
PubMed1980

Balanced translocation (10;13) in a father, ascertained through the study of meiosis in semen, and partial trisomy 10q in his son. Characterization of the region responsible for the partial trisomy 10q syndrome.

We describe a reciprocal translocation (10;13) in a man, ascertained through the study of meiosis in semen, and a partial trisomy 10q in his abnormal son. The phenotypic anomalies of the partial 10q trisomy syndrome are probably due to the presence in triplicate of the region q25 = to qter of chromosome 10.

Abnormalities, Multiple↗
PubMed1979

Chromosomal polymorphism and somatic segregation in Saimiri sciureus.

Quinacrine (Q) and Giemsa (G) banding, and sister chromatid exchange (SCE) studies have been carried out in Saimiri sciureus. In one male and one female studied, the diploid number was 2n = 44 and the karyotype corresponded to that described for the geographical region of Georgetown, Guyana. In the second male three different cell lines were observed, one corresponding to the geographical region of Leticia (Colombia), another to the geographical location of Iquitos (Peru) and a third line with 46 chromosomes. In the three lines, pair A2 was heterozygous, with nucleolar organizers of different size, and pari B6 was also heterozygous, with different amounts of heterochromatin in the short arms. The presence of three different cell lines in this male may be due to a mechanism of somatic segregation. The chromosomal changes involved in the intraspecific polymorphism found in Saimiri have been reinterpreted.

Animals↗
PubMed1978

Mosaicism in XX males.

Three males with a 46,XX karyotype are described. In two of them, evidence of a Y-containing line was found. In the first case, 1 of 500 lymphocyte metaphases was 48,XXY. In the second, 1 of 400 oral mucosa cells contained a Y body. The proportion of low-grade XX/XXY mosaics found among XX males now stands at about 17%.

Humans↗
PubMed1978

Banding patterns of the chromosomes of Nycticebus coucang (Boddaert, 1785).

Q, G and C banding studies of the chromosomes of Nycticebus coucang permitted the identification of all pairs in the complement. The X was a long submetacentric, the Y a rather long metacentric. All members of the complement were non-acrocentrics. The differences between the 2n = 52 and the 2n = 50 karyotypes described in this species may be due to a centric translocation mechanism.

Animals↗
PubMed1976

Banding patterns of the chromosomes of Cebus albifrons. Comparative study with Cebur apella.

Quinacrine- and Giemsa-banding studies of the chromosomes of Cebus albifrons permitted to obtain a pattern that characterizes the species. The topography of the bands has been compared with that of Cebus apella. Each chromosome pair of C. albifrons has a homologue in C. apella. The differences between the two karyotypes are the result of five pericentric inversions.

Animals↗