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Biomedical subjects

C Ligas

Publications and source records attributed to C Ligas.

8 recordsLinked to original sources
PubMed1997

Sister chromatid exchange (SCE) rates in human melanoma cells as an index of mutagenesis.

Melanomas are highly clonogenic. Genetic variability and polymorphism of tumour cell populations have been reported. However, no direct evidence of mutator activity as a source of genetic polymorphism for melanoma cells has been described. Some intermediates of melanin synthesis are cytotoxic and genotoxic and their mutagenic power has been described. We show here that the rate of sister chromatid exchange (SCE) of the line of human melanoma cells used varies with the concentration of the melanin precursor L-tyrosine, in the culture medium. An increase of melanin synthesis results in increased SCE rates. The highest values of SCEs are found in melanotic melanoma cells compared with the amelanotic ones. Indeed we present evidence that melanoma cells show higher levels of SCE when compared with normal human lymphocytes, and to the SCE frequencies derived from the literature on the lymphocytes of familial malignant melanoma, sporadic malignant melanoma patients and the lymphocytes of relatives of familial and sporadic melanoma patients.

Culture Media↗
PubMed1994

Cytogenetic findings in primary non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) shows a complex cytogenetic heterogeneity and up to now no particular chromosomal aberration seems to characterize its malignant evolution. We therefore performed cytogenetic analyses of 20 primary NSCLC, 8 adenocarcinomas and 12 squamous cell carcinomas on direct preparations or short-term cultures. Only 1 case was analyzed after long-term culture. Results were obtained from 11 samples and clonal rearrangements were found in 3 cases, a diploid and a near-triploid clone with several aberrations such as i (9q), rob (14; 15) and rob (21; 21) in 1 case, a near-triploid clone in 1 case, and Y chromosome loss in 1 case. Other aberrations found were sporadic, but +7 aneuploidy and translocations involving 1p were detected in 2 and 3 samples respectively. Although to date it has been very difficult to recognize primary changes in NSCLC, nevertheless a literature review and our results indicate that i(9q) and robertsonian translocations are relevant findings.

Aged↗
PubMed1994

Partial monosomy of 7q32 in a case of de novo rcp(7;15)(q32;q15).

A de novo apparently balanced translocation between chromosomes 7 and 15 with breakpoints in q32 and q15 respectively is reported in a female child. Clinical features included general growth and psychomotor retardation, feeding problems, microcephaly, low set ears, a short neck, and brachydactyly. These findings suggested possible physical or functional partial monosomy of the 7q32 or 15q15 segments. The phenotype of this case is similar to other cases of 7q deletion.

Abnormalities, Multiple↗
PubMed1992

Cytogenetic findings in terminal large cell transformation in a case of Sézary syndrome.

A long-lasting case of Sézary syndrome, whose chromosomal pattern had been repeatedly investigated during a follow-up period of several years, was studied in the terminal transforming phase, which took place more than 5 years after the initial diagnosis. To the best of the authors' knowledge, this appears to be the first instance of cytogenetic studies carried out in a large cell transformation of cutaneous T-cell lymphoma. The results clearly indicate that the atypical large cells seen in the transforming phase were clonally derived from the pre-existing cerebriform cells. Newly detected relevant cytogenetic findings were: a) drop of tumor cell ploidy from hypotetraploid to hypotriploid, with striking chromosomal imbalance; b) additional structural aberrations of chromosomes 2 and 7, which had been already preferentially involved in the earlier phases, and involvement of the previously unaffected chromosomes 1, 3, and X; and c) presence in 100% of the abnormal metaphases of a large HSR on the long arm of chromosome 17.

Aged↗
PubMed1991

Paracentric inversion of chromosome 15(q15q24): description of three families.

Three unrelated families with paracentric inversion of chromosome 15(q15q24) are reported. An additional pericentric inversion of chromosome 9 with breakpoints in p11.2q13 was also observed in one of the three families. Reproductive problems, such as stillbirths, spontaneous abortions and two live-born children with multiple abnormalities, were present.

Adult↗
PubMed1990

Nonrandom chromosome changes in multiple sclerosis.

In order to study the role of genetic factors in multiple sclerosis, cytogenetic analysis was performed on 48 patients with the clinically defined disease. We found a high incidence of subjects (50%) with abnormal chromosomes, showing premature centromere division of the X chromosome and structural aberrations, translocations, or deletions that could suggest preferential breakpoints. Correlation between clinical and cytogenetic data showed that cytogenetic abnormalities were more common in patients with high frequency of relapse or with a progressive form of the disease.

Adolescent↗
PubMed1990

Cytogenetic follow-up in a case of Sézary syndrome.

A cytogenetic follow-up study was performed for a 3-year period on a 70-year-old patient with Sézary syndrome (SS). The results showed formation of hypotetraploid cell clones with 60 to 89 chromosomes and 19 markers, some of which appeared during the period of study and stabilized thereafter. The incidence of these clonal cells increased from 29% to 85% during the follow-up study. The results confirm the presence of hypotetraploid cell clones, especially in the more advanced stages of SS. Moreover, some marker chromosomes in our patient (M2 and M3), derived from chromosome 2, were similar to those observed in SS by other investigators. According to our data and to those in the literature, SS appears to involve preferentially chromosomal regions 2p12-13, 2p21-22, 2q37, 17p13, 13q1, 9q11, 10p13, 14q11, 14q32, 7p1 and, to a lesser extent, 5q and 6q.

Aged↗