RESUMEN
OBJECTIVE: Mexican Cervical Cancer Screening Study II (MECCS II) seeks to develop a highly sensitive and highly specific screening program able to be adapted to all socioeconomic levels in Mexico. The objectives of MECCS II are (1) to compare the sensitivity and specificity for cervical intraepithelial neoplasia (CIN) 3 or cancer of self-collected vaginal specimens tested for high-risk types of the human papillomavirus (HR-HPV) by APTIMA with those tested for HR-HPV by Hybrid Capture 2 (HC2); and (2) determine the efficacy of cryotherapy in the treatment of HR-HPV-positive and acetic acid-aided visual inspection (VIA)-positive and -negative women after VIA triage. METHODS: The study was conducted in rural Mexico. Women aged 30 to 50 years, nonpregnant, with no history of hysterectomy or pelvic irradiation and varied histories of screening, participated. A direct endocervical sample was tested for cytology, HC2, and APTIMA assay (AHPV). Subjects positive on any test were recalled for triage VIA, biopsies, and immediate cryotherapy. Tests were compared using McNemar test. RESULTS: Two thousand forty-nine patients have complete results. Mean age of the patients was 39.2 years; 7.7% presented with ≥atypical squamous cells of uncertain significance (ASCUS), 1.8% ≥low-grade squamous intraepithelial neoplasia, and 0.5% ≥high-grade squamous intraepithelial neoplasia. Two percent of patients had ≥CIN2, and 0.78% had ≥CIN3 (including 2 with invasive disease). The sensitivity of ThinPrep (>ASCUS), HC2, and AHPV for >CIN3 for direct endocervical collection was 87.5%, 100%, and 100%, respectively. The specificity of ThinPrep (>ASCUS), HC2, and AHPV for >CIN3 was 94.1%, 92.2%, and 93.5%, respectively. Specificities of HC2 and AHPV differed significantly. The overall percentage of agreement among HPV assays (HC2 vs APTIMA) is 97%. Four hundred sixty-nine women returned for VIA. Two hundred ninety-one women were treated with cryotherapy. CONCLUSIONS: The specificity of the APTIMA assay along with high sensitivity is an advantage for primary screening. Follow-up evaluation will be important to determine the true impact of potential undertreatment in the screening algorithm. Self-sampling applications are explored.
Asunto(s)
Carcinoma de Células Escamosas/diagnóstico , Tamizaje Masivo , Infecciones por Papillomavirus/diagnóstico , Displasia del Cuello del Útero/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Ácido Acético , Adulto , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/virología , Cuello del Útero/patología , Citodiagnóstico , ADN Viral/genética , Detección Precoz del Cáncer , Femenino , Estudios de Seguimiento , Humanos , México/epidemiología , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Papillomaviridae/genética , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Prevalencia , Pronóstico , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Manejo de Especímenes , Displasia del Cuello del Útero/epidemiología , Displasia del Cuello del Útero/virología , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virología , Frotis VaginalRESUMEN
Pseudomonas aeruginosa is able to utilize leucine/isovalerate and acyclic terpenes as sole carbon sources. Key enzymes which play an important role in these catabolic pathways are 3-hydroxy-3-methylglutaryl-coenzyme A (CoA) lyase (EC 4.1.3.4; HMG-CoA lyase) and the 3-hydroxy-3-isohexenylglutaryl-CoA lyase (EC 4.1.2.26; HIHG-CoA lyase), respectively. HMG-CoA lyase is encoded by the liuE gene while the gene for HIHG-CoA lyase remains unidentified. A mutant in the liuE gene was unable to utilize both leucine/isovalerate and acyclic terpenes indicates an involvement of liuE in both catabolic pathways (Chávez-Avilés et al. 2009, FEMS Microbiol Lett 296:117-123). The LiuE protein was purified as a His-tagged recombinant protein and in addition to show HMG-CoA lyase activity (Chávez-Avilés et al. 2009, FEMS Microbiol Lett 296:117-123), also displays HIHG-CoA lyase activity, indicating a bifunctional role in both the leucine/isovalerate and acyclic terpenes catabolic pathways.
Asunto(s)
Proteínas Bacterianas/metabolismo , Oxo-Ácido-Liasas/metabolismo , Pseudomonas aeruginosa/enzimología , Electroforesis en Gel de Poliacrilamida , Redes y Vías Metabólicas , Proteínas Recombinantes/metabolismoRESUMEN
The enzymes involved in the catabolism of leucine are encoded by the liu gene cluster in Pseudomonas aeruginosa PAO1. A mutant in the liuE gene (ORF PA2011) of P. aeruginosa was unable to utilize both leucine/isovalerate and acyclic terpenes as the carbon source. The liuE mutant grown in culture medium with citronellol accumulated metabolites of the acyclic terpene pathway, suggesting an involvement of liuE in both leucine/isovalerate and acyclic terpene catabolic pathways. The LiuE protein was expressed as a His-tagged recombinant polypeptide purified by affinity chromatography in Escherichia coli. LiuE showed a mass of 33 kDa under denaturing and 79 kDa under nondenaturing conditions. Protein sequence alignment and fingerprint sequencing suggested that liuE encodes 3-hydroxy-3-methylglutaryl-coenzyme A lyase (HMG-CoA lyase), which catalyzes the cleavage of HMG-CoA to acetyl-CoA and acetoacetate. LiuE showed HMG-CoA lyase optimal activity at a pH of 7.0 and 37 degrees C, an apparent K(m) of 100 microM for HMG-CoA and a V(max) of 21 micromol min(-1) mg(-1). These results demonstrate that the liuE gene of P. aeruginosa encodes for the HMG-CoA lyase, an essential enzyme for growth in both leucine and acyclic terpenes.