Cytogenetic studies have an important role in the evaluation of couples with repeated miscarriages and poor obstetric history. To estimate the prevalence of chromosomal abnormalities and polymorphic variants in 158 couples with repeated miscarriages, a cross-sectional study was conducted in Monterrey, Mexico from 1995 to 2003. Peripheral blood lymphocytes were cultured for chromosomal studies using standard methods. Twelve couples showed chromosomal abnormalities (7.60%), two Robertsonian translocations (1.27%), two balanced translocations (1.27%), one inversion (0.63%), and one a novel insertion (0.63%). This insertion [46, XX, ins (15;8) (q26;p11p23)] is unique, and is the third reported in association with repeated abortion. Mosaicism was observed in six couples (3.80%, three with structural abnormalities and three with numerical abnormalities). A female to male ratio of 1.4:1 was observed. In addition to these chromosomal abnormalities, polymorphic variants in constitutive heterochromatin of the 1qh+, 9qh+, and 16qh+ chromosomes were observed in 25 couples (15.82%), of the Yqh+ chromosome in 21 couples (13.29%), and of satellite in 35 couples (22.15%). In conclusion, chromosome analysis is necessary for appropriate clinical management of these patients.

BACKGROUND Mycobacterium tuberculosis is an intracellular pathogen, which may either block cellular defensive mechanisms and survive inside the host cell or induce cell death. Several studies are still exploring the mechanisms involved in these processes.OBJECTIVESTo evaluate the genomic instability of M. tuberculosis-infected macrophages and compare it with that of uninfected macrophages.METHODSWe analysed the possible variations in the genomic instability of Mycobacterium-infected macrophages using the DNA breakage detection fluorescence in situ hybridisation (DBD-FISH) technique with a whole human genome DNA probe.FINDINGSQuantitative image analyses showed a significant increase in DNA damage in infected macrophages as compared with uninfected cells. DNA breaks were localised in nuclear membrane blebs, as confirmed with DNA fragmentation assay. Furthermore, a significant increase in micronuclei and nuclear abnormalities were observed in infected macrophages versus uninfected cells.MAIN CONCLUSIONSGenomic instability occurs during mycobacterial infection and these data may be seminal for future research on host cell DNA damage in M. tuberculosis infection.

This study investigated possible variations in DNA damage in HeLa cells with silenced expression of the HPV/E6 oncogene compared with HeLa cells with normal expression of the E6 oncogene using the DNA breakage detection-fluorescence in situ hybridization (DBD-FISH) technique and a whole human genome DNA probe. The variable levels of DNA breaks present were measured quantitatively using image analysis after whole-genome DNA hybridization. HeLa cells with silenced expression of the HPV18/E6 oncogene showed a significant decrease in DNA damage compared with parental cells with normal expression of the E6 oncogene. These results were confirmed by alkaline comet assay. In conclusion, we demonstrated a decrease in DNA damage in HeLa clones associated with low expression of the HPV/E6 oncogene. The significance of this decrease regarding the HPV life cycle and carcinogenesis requires further exploration.

Introduction: Knowing if the document that supports the informed consent (IC) granted by the patient who undergoes genetic laboratory tests is legible and understandable is important. Objective: To analyze the readability of IC documents for laboratory genetic tests (LGT) in Mexico. Methods: Readability of 10 free IC forms on the internet used for LGT was analyzed using the Legible.es program; the Flesh index, Fernández-Huerta version, and the INFLESZ scale were evaluated. The number of syllables, words, phrases, paragraphs and strange words, time to read the document and minimum years of education required to understand it were counted. Results: 60 % of the analyzed IC documents were found to have poor readability. On average, 3,290 syllables, 1,459 words, 124 sentences, 58 paragraphs and 52 strange words were counted. The time required for reading it was seven minutes and minimum level of education to understand it was six years. Conclusions: The analyzed IC forms for LGT have low readability rates and exceed the recommended number of words. We propose an IC model for LGT in Mexico that complies with appropriate readability indexes for a correct understanding of the document.