DNA Damage in Bat Blood Leukocytes Using a Chromatin Dispersion Test (CDT): Biomarker of Environmental Genotoxicity.

Environmental pollutants produce adverse effects on organisms and ecosystems. Biomonitoring and biomarkers offer a reasonable approach to make these assessments. Induced genetic changes can be using as a biomarker in organisms that react to a given compound in the ecosystem. Monitoring environmental genotoxicity necessitates the choice of model animals known as "sentinels or biological monitors" and the suitability of validated tests for DNA damage evaluation. We aimed to estimate the DNA damage produced by thermal stress in the leukocytes of the Mexican free-tailed bat (Tadarida brasiliensis). The DNA damage in bat leukocytes exposed to different temperatures (35 °C, 45 °C, and 55 °C) was evaluated by the adapted chromatin dispersion test (CDT) and the results were confirmed by the alkaline comet test. The CDT permitted a clear representation of leukocytes with fragmented DNA and of nonfragmented DNA. In addition, we detected nuclear anomalies in relation to cell death cellular swelling, nuclear fragmentation, and chromatin lysis. The alkaline comet assay revealed that the halos of diffuse chromatin include fragmented DNA. The assay of the method employing the CDT is well established, precise, and cost-effective for the routine quantitative analysis of DNA damage on the effect of the leukocytes of bats exposed to thermal stress. This could also apply as a sensitive screening tool for the evaluation of genotoxicity in environmental protection programs.

DBD-FISH Using Specific Chromosomal Region Probes for the Study of Cervical Carcinoma Progression.

Genomic instability is an important biomarker in the progression of cervical carcinoma. DBD-FISH (DNA breakage detection-fluorescence in situ hybridization) is a sensitive method that detects strand breaks, alkali-labile sites, and incomplete DNA excision repair in cells of the cervical epithelium. This technique integrates the microgel immersion of cells from a vaginal lesion scraping and the DNA unwinding treatment with the capacity of FISH integrated into digital image analysis. Cells captured within an agarose matrix are lysed and submerged in an alkaline unwinding solution that generates single-stranded DNA motifs at the ends of internal DNA strand breaks. After neutralization, the microgel is dehydrated and the cells are incubated with DNA-labeled probes. The quantity of a hybridized probe at a target sequence corresponds to the measure of the single-stranded DNA produced during the unwinding step, which is equivalent to the degree of local DNA breakage. DNA damage does not show uniformly throughout the entire DNA of a cell; rather, it is confined to specific chromosomal sites. In this chapter, an overview of the technique is supplied, focusing on its ability for assessing the association between DNA damage in specific sequences and in the progressive stages of cervical carcinoma.

Green synthesis of ethyl cinnamates under microwave irradiation: photophysical properties, cytotoxicity, and cell bioimaging.

A simple and green method for the synthesis of six ethyl cinnamates was performed via Horner-Wadsworth-Emmons reaction under microwave irradiation. The photoluminescent properties of all compounds in ethyl acetate solutions were evaluated demonstrating that all compounds exhibit fluorescence. Five compounds exhibited blue emissions in the 369-442 nm range, and another compound exhibited blue-green emission at 504 nm. This last compound showed the largest Stokes shift (134 nm), and the highest quantum yield (17.8%). Two compounds showed extinction coefficient values (ε) higher than 30 000 M-1 cm-1, which are appropriate for cell bioimaging applications. In this sense, cytotoxicity assays were performed using Vero cells at different concentrations; the results showed that these compounds were not cytotoxic at the highest concentration tested (20 µg mL-1). Finally, the analysis by fluorescence microscopy for localization and cellular staining using Vero cells demonstrated that the compounds stained the cytoplasm and the nuclei in a selective way.

Identification of variants in genes associated with hypertrophic cardiomyopathy in Mexican patients.

The objective of this work was to identify genetic variants in Mexican patients diagnosed with hypertrophic cardiomyopathy (HCM). According to world literature, the genes mainly involved are MHY7 and MYBPC3, although variants have been found in more than 50 genes related to heart disease and sudden death, and to our knowledge there are no studies in the Mexican population. These variants are reported and classified in the ClinVar (PubMed) database and only some of them are recognized in the Online Mendelian Information in Men (OMIM). The present study included 37 patients, with 14 sporadic cases and 6 familial cases, with a total of 21 index cases. Next-generation sequencing was performed on a predesigned panel of 168 genes associated with heart disease and sudden death. The sequencing analysis revealed twelve (57%) pathogenic or probably pathogenic variants, 9 of them were familial cases, managing to identify pathogenic variants in relatives without symptoms of the disease. At the molecular level, nine of the 12 variants (75%) were single nucleotide changes, 2 (17%) deletions, and 1 (8%) splice site alteration. The genes involved were MYH7 (25%), MYBPC3 (25%) and ACADVL, KCNE1, TNNI3, TPM1, SLC22A5, TNNT2 (8%). In conclusion; we found five variants that were not previously reported in public databases. It is important to follow up on the reclassification of variants, especially those of uncertain significance in patients with symptoms of the condition. All patients included in the study and their relatives received family genetic counseling.

[Complete androgen insensitivity syndrome: diagnosis and multidisciplinary management]. / Síndrome de insensibilidad completa a los andrógenos: diagnóstico y manejo multidisciplinario.

Background: Complete androgen insensitivity syndrome (CAIS) is a sexual differentiation disorder, caused by a defect in the androgen receptor gene (AR; OMIM# 313700). It is characterized by the resistance of target tissues to the action of testosterone, which prevents normal male genital development. The objective is to describe a family case of CAIS and highlight the importance of multidisciplinary medical management and early diagnosis of this syndrome. Clinical case: We present two cases of SICA in a Mexican family. Case 1: 18-year-old female patient with primary amenorrhea and a history of surgery at an early age, without performing gonadectomy. Case 2: 11-year-old female patient who, due to the history of her sister, underwent surgery at that age. In both patients, absence of uterus and ovaries, hypoplastic vagina and male gonads is reported. The 46,XY karyotype was detected with the GTG and CBG band technique and fluorescent in situ hybridization with the presence of the Y chromosome in 100% of the cells analyzed. Although both patients were identified with their assigned sex, they were referred to the institution's psychiatric clinic. Conclusions: The importance of multidisciplinary management for the diagnosis of SICA at an early age is discussed, in order to make decisions regarding the treatment and management of patients, avoiding malignant transformation of the male gonads.

Introducción: el síndrome de insensibilidad completa a los andrógenos (SICA) es un desorden de la diferenciación sexual, causado por un defecto en el gen receptor de andrógenos (AR; OMIM# 313700). Se caracteriza por la resistencia de los tejidos diana a la acción de la testosterona, lo que impide el desarrollo genital masculino de manera normal. El objetivo es describir un caso familiar de SICA y destacar la importancia del manejo médico multidisciplinario y el diagnóstico temprano de este síndrome. Caso clínico: presentamos dos casos de SICA en una familia mexicana. Caso 1: paciente de 18 años con amenorrea primaria y antecedente de intervención quirúrgica a edad temprana, sin realizarle gonadectomía. Caso 2: paciente de 11 años que debido al antecedente de su hermana fue intervenida quirúrgicamente a esa edad. En ambas pacientes, se reporta ausencia de útero y ovarios, vagina hipoplásica y gónadas masculinas. El cariotipo 46,XY fue detectado con técnica de bandas GTG y CBG e hibridación in situ fluorescente con presencia del cromosoma Y en el 100% de las células analizadas. Aunque ambas se identificaban con su sexo de asignación, fueron referidas a consulta de psiquiatría de la institución. Conclusiones: se discute la importancia del manejo multidisciplinario para el diagnóstico de SICA a edades tempranas con la finalidad de tomar decisiones respecto al tratamiento y manejo de las pacientes y evitar la malignización de las gónadas masculinas.

Readability analysis of informed consent forms for genetic tests in Mexico.

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.

INTRODUCCIÓN: Es importante conocer si el documento que ampara el consentimiento informado (CI) del paciente a quien se le realizan pruebas genéticas de laboratorio (PGL) es legible y comprensible. OBJETIVO: Analizar la legibilidad de documentos de consentimiento informado (CI) para pruebas genéticas de laboratorio (PGL) en México. MÉTODOS: Se analizó la legibilidad de 10 formatos de CI libres en internet utilizados para PGL mediante el programa Legible.es; se evaluó índice de Flesh, versión de Fernández Huerta, y la escala INFLESZ. Se contabilizó el número de sílabas, palabras, frases, párrafos y palabras raras, tiempo para leer el documento y años de escolaridad mínima para entenderlo. RESULTADOS: Se identificó que 60 % de los formatos de CI analizados son poco legibles. En promedio, se contabilizaron 3290 sílabas, 1459 palabras, 124 frases, 58 párrafos y 52 palabras raras. El tiempo requerido para la lectura fue de siete minutos y la escolaridad mínima de seis años. CONCLUSIONES: Los formatos de CI analizados tuvieron bajos índices de legibilidad y exceden el número recomendado de palabras. Proponemos un modelo de CI para PGL en México, que cumple con los índices de legibilidad para la correcta comprensión del documento.

Análisis de legibilidad de formatos de consentimiento informado para pruebas genéticas en México / Readability analysis of informed consent forms for genetic tests in Mexico

Resumen Introducción: Es importante conocer si el documento que ampara el consentimiento informado (CI) del paciente a quien se le realizan pruebas genéticas de laboratorio (PGL) es legible y comprensible. Objetivo: Analizar la legibilidad de documentos de CI para pruebas genéticas de laboratorio (PGL) en México. Métodos: Se analizó la legibilidad de 10 formatos de CI libres en internet utilizados para PGL mediante el programa Legible.es; se evaluó índice de Flesh, versión de Fernández Huerta, y la escala INFLESZ. Se contabilizó el número de sílabas, palabras, frases, párrafos y palabras raras, tiempo para leer el documento y años de escolaridad mínima para entenderlo. Resultados: Se identificó que 60 % de los formatos de CI analizados son poco legibles. En promedio, se contabilizaron 3290 sílabas, 1459 palabras, 124 frases, 58 párrafos y 52 palabras raras. El tiempo requerido para la lectura fue de siete minutos y la escolaridad mínima de seis años. Conclusiones: Los formatos de CI analizados tuvieron bajos índices de legibilidad y exceden el número recomendado de palabras. Proponemos un modelo de CI para PGL en México, que cumple con los índices de legibilidad para la correcta comprensión del documento.

Abstract 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.

Mycobacterium tuberculosis promotes genomic instability in macrophages

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. OBJECTIVES To evaluate the genomic instability of M. tuberculosis-infected macrophages and compare it with that of uninfected macrophages. METHODS We 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. FINDINGS Quantitative 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 CONCLUSIONS Genomic instability occurs during mycobacterial infection and these data may be seminal for future research on host cell DNA damage in M. tuberculosis infection.

Mycobacterium tuberculosis promotes genomic instability in macrophages.

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. OBJECTIVES: To evaluate the genomic instability of M. tuberculosis-infected macrophages and compare it with that of uninfected macrophages. METHODS: We 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. FINDINGS: Quantitative 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 CONCLUSIONS: Genomic instability occurs during mycobacterial infection and these data may be seminal for future research on host cell DNA damage in M. tuberculosis infection.

Chromosome segregation and chromatin integrity in spermatozoa from a t(2;8)(p24;p21)mat carrier: A case-report.

BACKGROUND: Chromosome rearrangements can produce genomic imbalance in gametes which causes a drastic decrease in fertility. Several studies have described the relationship between high levels of DNA damage and chromosomal alterations in the spermatozoa of infertile or subfertile males. However, the nature of this relation is poorly understood. In this study, the meiotic segregation pattern and chromatin integrity were analyzed in the ejaculated spermatozoa of a 46, XY, t(2;8)(p24;p21)mat carrier with normozoospermia and a lack of conception. CASE: A 39-year-old infertile man with a 46, XY, t(2;8)(p24;p21)mat inherited from his mother, was studied. The wife of the proband (30 yrs old) had a normal karyotype and no reproductive problems. The meiotic segregation pattern and aneuploidy of chromosome-8 and chromosome-2 were analyzed by FISH. Sperm DNA damage was evaluated by the Sperm Dispersion Chromatin, alkaline comet assay and DNA breaking detection. Five healthy male donors were included as controls. The frequency of genetically unbalanced spermatozoa was 61.6%. Analysis of the aneuploidy of chromosome-8 and chromosome-Y revealed approximately three and 24 fold increased level respectively in comparison with that of the control group. CONCLUSION: We suggest that the accumulation of genetically unbalanced spermatozoa, and increased sperm aneuploidy level is related to male infertility. Interestingly, the case described here has a high level of sperm chromosomal imbalance appears to be linked to sperm DNA fragmentation status. This information could be useful in assisted reproductive techniques.

Expression of the HPV18/E6 oncoprotein induces DNA damage.

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 detection­fluorescence in situ hybridization (DBD­FISH) 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.

Chromosome abnormalities in northeastern Mexico: ten years of experience in a private laboratory (1999-2009).

Throughout the world, chromosome alterations are one of the main causes of major malformations in newborns and of multiple clinical characteristics in patients of other ages. The present study had as its principle objective to determine the distribution of chromosome alterations obtained from 1999-2009 at a private laboratory located in Monterrey, Nuevo Leon state, Mexico, and that received samples from other northeastern Mexican states. We studied 1,652 cases of peripheral blood karyotypes. Samples were obtained from patients in whom there was a suspicion of some chromosome alteration based on the clinical history. Of the karyotypes evaluated, 1,250 (76.0%) had normal karyotype, 320 (19.0%) presented chromosome alterations, among which 270 (84%) were numerical, 50 (16%) were structural, and 82 (5.0%) were polymorphisms. Chromosome alteration frequency and type found in the present study is similar to that found in studies conducted in other countries and to that reported in the literature.

Chromosomal abnormalities and polymorphic variants in couples with repeated miscarriage in Mexico.

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.