RESUMO
This study aimed to assess the suitability of egg yolk (EY) supplementation to a tris-citric acid-based extender on cryosurvival of guinea pig (Cavia porcellus) epididymal spermatozoa. Two synthetic-based extenders, tris-citric acid-glucose plus 20% EY (TCG-EY) and tris-citric acid-fructose (TCF) both with 5% glycerol, were compared. Thirty-two epididymides were recovered from 16 adult guinea pig males by gonadectomy, and then the sperm samples were retrieved by retrograde flushing using TCG-EY and TCF extenders for left or right epididymis, respectively. TCG-EY and TCF sperm samples were frozen in static liquid nitrogen vapors through a two-step cooling procedure. Before freezing, the percentage of progressive sperm motility and sperm with intact plasma and acrosome membranes from TCG-EY sperm samples were higher (p < 0.05) than those diluted with TCF. Post-thaw sperm kinematic variables and membrane integrity were drastically reduced (p < 0.001) compared with prefreezing samples, regardless of extender type. The post-thaw plasmatic and acrosome membrane integrity from TCG-EY sperm samples was higher (p < 0.05) than those from TCF samples. Except for the length, the morphometric head dimensions of sperm diluted with TCG-EY or TCF did not vary (p > 0.05) after the freezing-thawing process compared with the prefreezing samples. In conclusion, despite greater cell cryoinjury with both extenders, the EY supplementation exerted greater cell membrane protection before and after the freezing-thawing process. This research shows an in-depth analysis of guinea pig sperm cryopreservation; however, more studies are recommended.
RESUMO
Introducción. El cáncer de mama es una enfermedad muy heterogénea a nivel clínico, morfológico y biológico, que se clasifica en diferentes subgrupos. El tipo «triple negativo» representa el 10-20% de todos los cánceres de mama, frecuentemente muestra expresión de marcadores basales, afecta a mujeres jóvenes y tiene mal pronóstico, sin una terapia dirigida. Material y método. Estudio retrospectivo de análisis de tres alteraciones moleculares (mutación de EGFR y PIK3CA e hipermetilación del promotor del gen BRCA1), mediante la técnica de pirosecuenciación, en 60 casos de cáncer de mama «triple negativo». Resultados. Un 28,33% de las pacientes fueron diagnosticadas con 50 o menos años, y el 16,67% progresaron por diseminación vía hematógena con metástasis viscerales y murieron (menos una) en un intervalo de entre 1-5 años desde el diagnóstico. En 5 de los 16 casos estudiados se encontró una mutación patogénica de BRCA. Inmunohistoquímicamente la mayoría eran tumores con alto índice proliferativo de Ki67 y un 73,33% eran «basal-like» por expresión de CK5/6 y/o EGFR. A nivel molecular, no se encontraron mutaciones activadoras de EGFR, aunque el 53,33% de los casos mostraron sobreexpresión inmunohistoquímica de EGFR. La mutación de PIK3CA se detectó en un 10% de casos, con predominio en exón20 y con coexpresión de receptores de andrógenos en la mitad de los casos. La hipermetilación de la región promotora del gen BRCA1 estaba presente en un 25% de los casos, coexistiendo en un caso con hipermetilación del estroma no tumoral y en dos con mutación patogénica del gen BRCA1. Conclusiones. El hallazgo de alguna alteración molecular específica, aunque sea infrecuente, puede plantear una posible diana terapéutica dirigida (AU)
Introduction. Breast cancer is a clinically, morphologically and biologically heterogeneous disease. It is classified in distinct subtypes. Triple-negative breast cancers represent approximately 10-20% of all breast cancers and often express basal markers. This type preferentially affects young women and has no specific therapy. Material and method. We conducted a retrospective study of three molecular alterations (the EGFR and PIK3CA mutations and BRCA1 promoter hypermethylation) by pyrosequencing in a series of 60 patients with a diagnosis of triple-negative breast cancer. Results. A total of 28.33% of patients were diagnosed at age 50 years or younger. Only 16.67% of patients had clinical progression due to haematological dissemination with visceral metastasis and all of them, except one, died from breast cancer between 1 and 5 years after diagnosis. The BRCA1 mutation was studied in 16 patients and a known pathogenic mutation was found in 5. Immunohistochemical study showed a high Ki67 proliferative index and 73.33% of carcinomas were basal-like due to CK5/6 and/or EGFR expression. Although we found no EGFR-activating mutations, EGFR overexpression was present in 53.33% of patients. The PIK3CA mutation was identified in 10% of patients, predominantly in exon 20 and with androgen receptor expression in half of these patients. BRCA1 promoter hypermethylation was observed in 25% of the patients. Only one of these patients exhibited BRCA1 hypermethylation of non-tumoural stroma and two showed a pathogenic mutation of the BRCA1 gene. Conclusion. The finding of specific molecular alterations, although infrequent, could suggest a possible directed therapeutic target (AU)
