RESUMEN
Certain human papillomaviruses (HPV), mainly types 16 and 18, have been widely recognized as an essential etiologic factor for the development of carcinoma of the uterine cervix. The early HPV proteins E6 and E7 are consistently expressed in the tumor cells, and cervical-carcinoma patients can develop antibodies against these oncoproteins. For cervical-carcinoma patients from Eastern Europe and Russia, detailed information on HPV DNA prevalence and HPV-specific immune responses is limited. The presence of HPV DNA in 128 Russian cervical-carcinoma tissues was determined: HPV16 DNA was found in 78% of the cases, HPV18 DNA in 14%, and no HPV-DNA in 10%. Using 4 recently developed sensitive and highly specific second-generation enzyme-linked immunosorbent assays, we also analyzed the prevalence of antibodies against HPV16 and -18 E6 and E7 proteins in sera from 95 cervical-carcinoma patients, from 61 female patients with non-HPV-associated tumors and from 83 female healthy controls. The strong association of E6 and/or E7 antibodies with cervical carcinoma was confirmed, with 36% seropositives in this group against only 2% in the control groups. The detected antibodies are highly HPV-type-specific since all 26 HPV16-E6- or -E7-antibody-positive patients had HPV16 DNA in their tumor and 6 out of the 8 HPV18-antibody-positive patients had HPV18 DNA. Antibody responses to HPV16 E6 and E7 appear to be dependent on clinical stage of the disease, with 21% seropositives found in FIGO stage I, 42% in stage II and 53% in stage III. Antibody response to HPV16 E6 is more frequent than to E7, especially in early stages.
Asunto(s)
Anticuerpos Antivirales/análisis , Carcinoma/virología , ADN Viral/análisis , Proteínas de Unión al ADN , Proteínas Oncogénicas Virales/inmunología , Papillomaviridae , Infecciones por Papillomavirus/inmunología , Infecciones Tumorales por Virus/inmunología , Neoplasias del Cuello Uterino/virología , Adulto , Anciano , Anticuerpos Antivirales/sangre , Carcinoma/inmunología , Carcinoma/patología , Estudios de Casos y Controles , ADN Viral/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Papillomaviridae/genética , Papillomaviridae/inmunología , Infecciones por Papillomavirus/complicaciones , Prevalencia , Federación de Rusia , Infecciones Tumorales por Virus/complicaciones , Neoplasias del Cuello Uterino/inmunología , Neoplasias del Cuello Uterino/patologíaRESUMEN
Chromosome 6 is frequently affected in different tumors. However, little information exists on chromosome 6 deletions in cervical cancer. We have studied loss of heterozygosity (LOH) and microsatellite instability (MIN) in 62 invasive squamous cell carcinomas of the cervix (CC) using 19 polymorphic microsatellite markers spanning both arms of chromosome 6 and one marker located at 5p15. We found that LOH at chromosome 6 is a common feature of cervical carcinomas: 90% (56/62) of CC had LOH at least at one locus and about 58% (36/62) had LOH on both arms of chromosome 6. The highest LOH incidence was shown in HLA region (6p21.3-6p21.1) with markers D6S273 and D6S276 in 52.7% and 45.2% of informative cases respectively. Frequent LOH on 6q was found at loci D6S311 (6q24-25. 1), D6S305 (6q26) and D6S281 (6q27-6qter) in 37.8%, 33.3% and 39.0% of informative cases respectively. There was no significant correlation observed between clinical parameters of cervical cancer (age, histologic grade, clinical stages and progression) and LOH frequency. Microsatellite instability was found in 3 out of 62 cases (4.8%) at three and more loci out of 20 tested. The study shows that several regions on 6p and 6q may harbour potential tumor-suppressor genes important for cervical cancer progression.
Asunto(s)
Carcinoma de Células Escamosas/genética , Cromosomas Humanos Par 6 , Pérdida de Heterocigocidad , Neoplasias del Cuello Uterino/genética , Mapeo Cromosómico , Progresión de la Enfermedad , Femenino , Humanos , Repeticiones de Microsatélite/genéticaRESUMEN
Nanometer-size presolar diamonds from the Efremovka CV3 chondrite were physically separated into several grain size fractions by ultracentrifugation. The coarsest size fraction is the most enriched in carbon-12; the others have broadly similar carbon isotopic compositions. Measurement of noble gases shows that their concentration decreases with decreasing grain size. This effect is attributed to ion implantation. Such an episode could occur in the envelope of a supernova that produced the diamonds, or in interstellar space; in either case, ions with energies above a certain threshold pass completely through the smaller diamond grains without being captured. Concentrations of nitrogen show only minor variations with grain size, indicating a different mechanism of incorporation into the diamonds.