Abstract Background: Gallbladder cancer (GBC) is the most common tumor of the biliary tract. The incidence of GBC shows a large geographic variability, being particularly frequent in Native American populations. In Chile, GBC represents the second cause of cancer-related death among women. We describe here the establishment of three novel cell lines derived from the ascitic fluid of a Chilean GBC patient, who presented 46% European, 36% Mapuche, 12% Aymara and 6% African ancestry. Results: After immunocytochemical staining of the primary cell culture, we isolated and comprehensively characterized three independent clones (PUC-GBC1, PUC-GBC2 and PUC-GBC3) by short tandem repeat DNA profiling and RNA sequencing as well as karyotype, doubling time, chemosensitivity, in vitro migration capability and in vivo tumorigenicity assay. Primary culture cells showed high expression of CK7, CK19, CA 19-9, MUC1 and MUC16, and negative expression of mesothelial markers. The three isolated clones displayed an epithelial phenotype and an abnormal structure and number of chromosomes. RNA sequencing confirmed the increased expression of cytokeratin and mucin genes, and also of TP53 and ERBB2 with some differences among the three cells lines, and revealed a novel exonic mutation in NF1. The PUC-GBC3 clone was the most aggressive according to histopathological features and the tumorigenic capacity in NSG mice. Conclusions: The first cell lines established from a Chilean GBC patient represent a new model for studying GBC in patients of Native American descent.

Background: The dose of oral anticoagulants (OAC) shows great variability among patients. Pharmacogenetic studies have shown that common variants in genes CYP2C9 (*2 and *3) and VKORC1 (-1639G>A) are associated with lower requirements of OAC. Aim: To study the association between average maintenance doses of oral anticoagulant therapy required to maintain a stable INR and CYP2C9 and VKORC1 gene variants in Chilean adults. Material and Methods: Prospective study of patients on anticoagulant treatment and with a stable international normalized ratio (INR) for prothrombin time for at least three months. Patients were classified as having high or low acenocoumarol or warfarin requirements. Peripheral blood DNA genotyping was performed by polymerase chain reaction and restriction fragment polymorphism or sequencing and electrophoresis. Results: The study included 185 patients, 125 on acenocoumarol and 60 on warfarin. Patients with VKORC1-1639A allele were more likely to require lower doses of both drugs than patients with the G allele (Odds ratio [OR] for acenocoumarol 9.06, and OR for warfarin = 18.7). There was no association between CYP2C9*2 and*3 and acenocoumarol or warfarin requirements. Conclusions: There is an association between VKORC1-1639A variant and anticoagulant doses.

Background: Molecular techniques for human papillomavirus (HPV) detection have a good performance as screening tests and could be included in cervical cancer early detection programs. We conducted a population-based trial comparing HPV detection and Papanicolaou as primary screening tests, in a public health service in Santiago, Chile. Aim: To describe the experience of implementing this new molecular test and present the main results of the study. Material and Methods: Women aged 25 to 64 enrolled in three public health centers were invited to participate. In all women, samples were collected for Papanicolaou and HPV DNA testing, and naked-eye visual inspection of the cervix with acetic acid was performed. Women with any positive screening test were referred to the local area hospital for diagnostic confirmation with colposcopy and biopsy of suspicious lesions. Results: Screening results were obtained for 8265 women, of whom 931 (11.3%) were positive to any test. The prevalence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was 1.1%; nine women had invasive cervical cancer. Sensitivities for the detection of CIN2+ were 22.1% (95% confidence interval (CI) 16.4-29.2) for Papanicolaou and 92.7% (95% CI 84.4-96.8) for HPV testing; specificities were 98.9% (95% CI 98.7-99.0) and 92.0% (95% CI 91.4-92.6) respectively. Conclusion: This experience showed that the implementation of a molecular test for cervical cancer screening is not a major challenge in Chile: it was well accepted by both the health team and the participants, and it may improve the effectiveness of the screening program.

Background: Although P. jiroveci pneumonia affects immunocompromised (IC) patients of any etiology, clinical features and prognostic outcomes are different depending if they are patients with HIV infection or other causes of IC. Objectives: To compare clinical and laboratory features as well as outcomes of P. jiroveci pneumonia in HIV versus non-HIV patients. Methods: Retrospective review of clinical records of HIV and non-HIV patients with P. jiroveci pneumonia managed at the Hospital Clínico Universidad Católica in Santiago, Chile, between 2005 and 2007. Results: We included 28 HIV and 45 non-HIV patients with confirmed P. jiroveci pneumonia. The non-HIV population was older (65 vs 36,2 years, p < 0,01), had shorter duration of symptoms (7 [1-21] vs 14 [2-45] days, p < 0,01), required more invasive techniques (60 vs 21%, p < 0,01) and RT-PCR to confirm the diagnosis (93 vs 68%, p < 0,01), were more frequently treated at intensive care units (58 vs. 25%, p < 0,01) requiring artificial ventilation (56 vs 11%, p < 0,01), and had a higher attributable mortality (33% vs 0%, p < 0,01). Conclusions: Our study confirmed that P. jiroveci pneumonia in non-HIV IC patients is more severe, more difficult to diagnose and has higher mortality that in HIV patients. Therefore, it is mandatory to optimize diagnostic and therapeutic strategies for this patients group.

Introducción: Pneumocystis jiroveci puede causar neumonía en pacientes inmunocomprometidos de cualquier etiología, pero las diferencias clínicas y pronósticas entre inmunocomprometidos por VIH y por otras causas han sido poco exploradas. Objetivo: Comparar las características clínicas, de laboratorio y pronóstico de neumonía por P. jiroveci en pacientes inmunocomprometidos por infección VIH versus no infectados por VIH. Métodos: Análisis retrospectivo de casos confirmados de neumonía por P. jiroveci en adultos con infección por VIH y no infectados, entre los años 2005 y 2007. Resultados: Se incluyeron 28 pacientes infectados por VIH y 45 no infectados, con neumonía por P. jiroveci confirmada. La población no infectada por VIH presentaba mayor edad (65 vs 36,2 años, p < 0,01), menor duración de síntomas previos a la consulta (7 [121] vs 14 [2-45] días, p < 0,01), mayor requerimiento de técnica invasora (60 vs 21%, p < 0,01) y estudio molecular (93 vs 68%, p < 0,01) para confirmación diagnóstica, mayor requerimiento de camas críticas (58 vs 25%, p < 0,01), y ventilación mecánica (56 vs 11%, p < 0,01), con mayor mortalidad atribuible (33 vs 0%, p < 0,01). Conclusiones: La neumonía por P. jiroveci en pacientes inmunocomprometidos no infectados por VIH ofrece más dificultades diagnósticas y presenta mayor gravedad y mortalidad que en pacientes con infección por VIH; por esto, es mandatario optimizar los procesos diagnóstico y terapéutico en esta población.

Mortality rates for cervical cancer (CC) in Chile are higher than those of developed countries and it has an unequal socioeconomic distribution. The recognition of human papilloma virus (HPV) as the causal agent of cervical cancer in the early 80’s changed the prevention paradigms. Current goals are to prevent HPV infection by vaccination before the onset of sexual activity and to detect HPV infection in women older than 30 years. This article reviews CC prevention and early detection methods, discusses relevant evidence to support a change in Chile and presents an innovation proposal. A strategy of primary screening based on HPV detection followed by triage of HPV-positive women by colposcopy in primary care or by cytological or molecular reflex testing is proposed. Due to the existence in Chile of a well-organized nationwide CC prevention program, the replacement of a low-sensitivity screening test such as the Papanicolau test with a highly sensitive one such as HPV detection, could quickly improve the effectiveness of the program. The program also has a network of personnel qualified to conduct naked-eye inspections of the cervix, who could easily be trained to perform triage colposcopy. The incorporation of new prevention strategies could reduce the deaths of Chilean women and correct inequities.

OBJECTIVE: To evaluate acceptance, preference and compliance with referral of vaginal self-sampling for the detection of Human papillomavirus (HPV) among women non-adherent to Papanicolaou (Pap) screening in Santiago, Chile. MATERIALS AND METHODS: Using multistage sampling we identified women aged 30-64 years who reported not receiving a Pap test in the previous three years and offered them Pap testing at the health center or vaginal self-sampling for HPV testing at home. Self-collected samples were analyzed with hybrid capture. All HPV+ women were referred for colposcopy, biopsy and treatment when needed. RESULTS: 1 254 eligible women were contacted; 86.5% performed self-sampling and 8.1% refused; 124 women were HPV+ (11.4%: 95%CI 9.6-13.5) of whom 85.5% attended colposcopy; 12 had CIN2+ (1.1%: 95 %CI 0.5-1.7). CONCLUSION: HPV vaginal self-sampling can be easily implemented in Chile and could improve coverage, successfully reaching women who drop out of the screening program.

OBJETIVO: Evaluar la aceptación, preferencia y adherencia a seguimiento de la autotoma vaginal para detección del virus del papiloma humano (VPH) en mujeres inasistentes a Papanicolaou (Pap) en Santiago, Chile. MATERIAL Y MÉTODOS: Mediante un muestreo polietápico se identificaron mujeres entre 30 y 64 años inasistentes a Pap por < 3 años, invitándolas a realizarse un Pap en su centro de salud o una autotoma vaginal a domicilio. Las muestras fueron analizadas con captura de híbridos. Las mujeres VPH+ fueron referidas a colposcopía, biopsia y tratamiento en caso necesario. RESULTADOS: 1 254 mujeres elegibles fueron contactadas; 86.5% aceptó la autotoma vaginal y 8.1% la rechazó; 124 mujeres resultaron VPH+ (11.4%: IC95% 9.6-13.5) de las que 85.5% asistió a colposcopía; 12 tenían CIN2+ (1.1%: IC95% 0.5-1.7). CONCLUSIÓN: La autotoma vaginal para detección de VPH es implementable en Chile y su utilización podría mejorar la cobertura del programa rescatando a mujeres inasistentes.

OBJECTIVE: To evaluate acceptance, preference and compliance with referral of vaginal self-sampling for the detection of Human papillomavirus (HPV) among women non-adherent to Papanicolaou (Pap) screening in Santiago, Chile. MATERIALS AND METHODS: Using multistage sampling we identified women aged 30-64 years who reported not receiving a Pap test in the previous three years and offered them Pap testing at the health center or vaginal self-sampling for HPV testing at home. Self-collected samples were analyzed with hybrid capture. All HPV+ women were referred for colposcopy, biopsy and treatment when needed. RESULTS: 1 254 eligible women were contacted; 86.5% performed self-sampling and 8.1% refused; 124 women were HPV+ (11.4%: 95%CI 9.6-13.5) of whom 85.5% attended colposcopy; 12 had CIN2+ (1.1%: 95 %CI 0.5-1.7). CONCLUSION: HPV vaginal self-sampling can be easily implemented in Chile and could improve coverage, successfully reaching women who drop out of the screening program.

OBJETIVO: Evaluar la aceptación, preferencia y adherencia a seguimiento de la autotoma vaginal para detección del virus del papiloma humano (VPH) en mujeres inasistentes a Papanicolaou (Pap) en Santiago, Chile. MATERIAL Y MÉTODOS: Mediante un muestreo polietápico se identificaron mujeres entre 30 y 64 años inasistentes a Pap por < 3 años, invitándolas a realizarse un Pap en su centro de salud o una autotoma vaginal a domicilio. Las muestras fueron analizadas con captura de híbridos. Las mujeres VPH+ fueron referidas a colposcopía, biopsia y tratamiento en caso necesario. RESULTADOS: 1 254 mujeres elegibles fueron contactadas; 86.5% aceptó la autotoma vaginal y 8.1% la rechazó; 124 mujeres resultaron VPH+ (11.4%: IC95% 9.6-13.5) de las que 85.5% asistió a colposcopía; 12 tenían CIN2+ (1.1%: IC95% 0.5-1.7). CONCLUSIÓN: La autotoma vaginal para detección de VPH es implementable en Chile y su utilización podría mejorar la cobertura del programa rescatando a mujeres inasistentes.

Background: Hemophilia A is an inherited disorder caused by alterations in factor VIII gene (F8) located on the X-chromosome, the intron 22 inversion being the most common mutation. The rest are predominantly point mutations distributed along this large gene of 26 exons. Aim: To implement a molecular diagnostic test to detect mutations in the F8 gene in Chilean patients with Hemophilia A. Material and Methods: To validate the testing methods, we analyzed samples with intron 22 and intron 1 inversion, and with point mutations previously studied, as well as one subject without Hemophilia. We also studied unrelated Chilean patients with Hemophilia A and their female relatives for carrier testing. Intron 22 and intron 1 inversions were studied by long distance polymerase chain reaction (PCR) and point mutations by sequencing the coding and promoter regions of the F8 gene. Results: The results obtained in all samples used for validation were concordant with those obtained previously. In the Chilean patients, the intron 22 inversion and point mutations previously described were observed. In 6 out of 9 patients with mild Hemophilia A we found the same mutation (Arg2159Cys) in exon 23, which has been described as prevalent in mild Hemophilia A. Conclusions: The analysis of intron 22 and intron 1 inversions, as well as of point mutations in the F8 gene will help us to confirm the diagnosis in patients with severe, moderate and mild Hemophilia A, and also it will allow us to perform carrier testing and to provide better genetic counseling.

It has been demonstrated that HLA-B*5701 screening reduces the risk for hypersensitivity reaction to abacavir in HIV-infected patients. Since B*5701 prevalence varies among different populations, it is important to determine the carrier frequency prior to its use for the screening of HIV-infected patients.The aim of this study was to determine HLA-B*5701 carrier frequency in Chilean general population and HIV-infected patients referred for B*5701 typing. For that purpose 300 blood bank donors and 492 abacavir-naïve HIV-infected patients from Chile were screened for B*5701 by a sequence specific primer PCR.We detected 14/300 (4.7%) B*57-positive individuals in the Chilean general population, 11 (3.7%) were B*5701 positive, and 3 (1%) had another subtype.All were heterozygous,thus a B*5701 allele frequency of 2% was determined.Eleven of 492 (2.2 %) HIV-patients carried a B*5701 allele. The difference between these frequencies is probably due to slow progression of HIV infection in HLA-B*5701 carriers, thus less patients would require antiretroviral therapy and B*5701 typing. Considering the usefulness of B*5701 screening, its prevalence in the Chilean general population,and the availability of a validated method,we conclude that HLA-B*5701 typing in Chilean HIV-infected patients about to initiate abacavir treatment is strongly recommended

Background: Metallo-ß-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. Aim: To detect the presence of MBL in imipenem resistant Psae strains. Material and methods: Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains, were studied by pulse field gel electrophoresis. Results: The presente of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. AH the strains were also multiresistant. Conclusions: The presence of MBL was detected in 19% of imipenem resistant Psae strains