Browsing by Author "Aguayo González, Francisco Renan"

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    Búsqueda de mutaciones en el gen UL 97 asociadas a resistencia a ganciclovir en citomegalovirus obtenidos desde muestras biológicas de pacientes chilenos
    (2010) Oyarzún Andrade, María Angélica; Bustos, Patricia; González Agüero, Marcela Margot; Domínguez Moreno, María Isabel; Aguayo González, Francisco Renan; Nervi Nattero, Bruno; Ferrés, Marcela
    Background: Long term use of ganciclovir (GCV) is associated with acquired resistance to it. Ninety percent of the responsible mutations occur in cytomegalovirus (CMV) UL97 gene. Aim: To search for these mutations, comparing nucleotide sequences of CMV-positive samples from post transplant and immunocompromised patients receiving GCV, with sequences of CMV isolates obtained from subjects not exposed to the drug. Patients and Methods: Codons 440 to 465 of gene UL97, including the most common mutations causing resistance to GCV, were amplified in 33 plasma samples from patients exposed to GCV and in 15 urine samples of newborns. Both populations and their nucleotide sequences were compared with the prototype strain CMV AD169. Results: Samples of exposed patients had multiple mutations but only one had a mutation associated with clinical resistance (M4601). Eight subjects had the D605E mutation, whose role in resistance is controversial. The remaining 150 mutations were silent mutations. Conclusions: A low frequency of mutations associated with CMV resistance to GCV was found in these exposed and unexposed samples. These mutations may reflect coexistence of multiple genetic variants of CMV. The absence of clinical expression of resistance, even with these mutations, can be explained by the use of GCV for a shorter lapse than that associated with the appearance of resistance. (Rev Med Chile 2010; 138: 421-427).
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    Factores de riesgo de alteraciones citológicas del cuello uterino en mujeres Chilenas: Un estudio de casos y controles
    (2010) Solís, M. T.; Aguayo González, Francisco Renan; Vargas, M.; Olcay, F.; Puschel Illanes, Klaus; Corvalán Rodríguez, Alejandro; Ferreccio Readi, Catterina
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    Genotipos de virus papiloma humano (VPH) en pacientes con cáncer cérvico-uterino en un hospital público y una clínica privada de Santiago, Chile
    (2010) Valdivia Leiva, Isabel Margarita; Aguayo González, Francisco Renan; Pruyas A., Martha; Snijders, Peter J. F.; Corvalán Rodríguez, Alejandro; Ferreccio Readi, Fresia Catterina
    We compared HPV genotypes among squamous cervical cancer samples from a public hospital (n = 55) and a private clinic (n = 35 cases) of Santiago. Paraffin-embedded specimens were analyzed by PCR followed by an immunoenzimatic assay. Reverse line blotting was used for the identification of 36 HPV genotypes. We found HPV DNA in 94.4% of all cancers. Single infections: HPV16: 40.0%, (clinic 37.1%, hospital 41.8%) VPH18:7.8% (clinic 2.9%, hospital 10.9%); single+multiple infections: VPH16: 61.1% (clinic 53.1%, hospital 71.7%), VPH18: 34.4% (clinic 21.9%, hospital 45.2%). HPV16 or HPV18 occurred in 75.6% of cases, higher in the hospital than the clinic (87.3%-95% CI: 84.9-96.3 - and 57.1%-95% CI: 46.6-66 - respectively, p = 0.002). Other genotypes in single infections: HPV 26, 31, 33, 45, 58, 67; in co-infections: HPV 35,52,56,59 and 66. HPV16 but specially HPV18 were significantly more frequent in the public hospital; 75.6% of squamous cervical cancer were associated to the vaccine preventable HPV16/18.