A novel human adenovirus hexon protein of species D found in an AIDS patient.

To date, human adenoviruses are classified into 53 types (types 1-51 and types 53 and 54), which have been grouped into six species named A through F, and the recently identified type 52 has been proposed as member of a new species, G. Type classification is based on type-specific epitopes within loop 1 (L1) and loop 2 (L2) of the hexon protein, which contain seven hypervariable regions that are responsible for type specificity. In this paper, we present the characterization of an adenovirus strain isolated from a male AIDS patient in Cordoba, Argentina. This strain was found to be a member of species D by genomic Sma I restriction analysis. Sequencing of the L1 and L2 regions of the hexon gene and immunological characterization by virus neutralization revealed this hexon to be unique and distinct from the previously identified hexons of types within species D. A seroepidemiologic study in the human population of Cordoba showed that this strain was not endemic in the local human population.

[Human herpesvirus-6 circulation in healthy adults and oncologic patients]. / Circulación del virus Herpes 6 humano en adultos normales y en pacientes oncológicos.

The aim of this paper was to assess the prevalence of antibodies to HHV-6 in the general population and study the virus circulation among individuals with cancer, in order to analyze HHV-6 involvement in lymphoproliferative disorders. A total of 200 sera from the general population and 67 from patients with neoplasia were studied. The latter were divided in 3 groups: lymphoma/myeloma, leukemia and non-immune solid tumors. HHV-6 antibodies (IgG and IgM) were assayed by IFA and viral genomes were detected using nested PCR. The prevalence of the infection in the healthy population was 63.5% with a titer geometric mean (TGM) of 48.67 +/- 1.23. A control group was obtained by systematic sampling of the healthy population. Among the patients with neoplasia, the prevalence was 95.5%. In the lymphoma/myeloma group, TGM was 268.73 +/- 1.62; in the leukemia group it was 151.1 +/- 1.88 and in the non-immunogenic solid tumors group it was 95.67 +/- 1.57. Statistically significant differences were observed (p < 0.01) between the control group and the lymphoma/myeloma and leukemia groups. Serum IgM or free viral genomes were not detected in any serum sample. The antibody prevalence found in the general population documents the high circulation of this lymphotropic virus which could indirectly contribute to the pathogenesis of the lymphoproliferative disorder.

Circulacion del virus Herpes 6 humano en adultos normales y en pacientes / Human herpesvirus-6 circulation in healthy adults and oncologic patients

The aim of this paper was to assess the prevalence of antibodies to HHV-6 in the general population and study the virus circulation among individuals with cancer, in order to analyze HHV-6 involvement in lymphoproliferative disorders. A total of 200 sera from the general population and 67 from patients with neoplasia were studied. The latter were divided in 3 groups: lymphoma/myeloma, leukemia and non-immune solid tumors. HHV-6 antibodies (IgG and IgM) were assayed by IFA and viral genomes were detected using nested PCR. The prevalence of the infection in the healthy population was 63.5 percent with a titer geometric mean (TGM) of 48.67 +/- 1.23. A control group was obtained by systematic sampling of the healthy population. Among the patients with neoplasia, the prevalence was 95.5 percent. In the lymphoma/myeloma group, TGM was 268.73 +/- 1.62; in the leukemia group it was 151.1 +/- 1.88 and in the non-immunogenic solid tumors group it was 95.67 +/- 1.57. Statistically significant differences were observed (p < 0.01) between the control group and the lymphoma/myeloma and leukemia groups. Serum IgM or free viral genomes were not detected in any serum sample. The antibody prevalence found in the general population documents the high circulation of this lymphotropic virus which could indirectly contribute to the pathogenesis of the lymphoproliferative disorder.

Aislamiento de Chlamydia Trachomatis y respuesta inmune en diferentes poblaciones / Isolation of Chlamydia trachomatis and immune response in different populations

Se estudió la presencia de IgG específica para C. trachomatis en diferentes grupos de pacientes adultos y la presencia de IgM en los neonatos y se relacionaron con el aislamiento de la bacteria en cultivos celulares. Se empleó un método de IFI sobre células McCoy, infectadas con el serotipo L(2)434/Bu de C. trachomatis. El método demostró ser específico, sensible y reproducible, utilizando las placas de plástico de 24 pozos para hacer crecer las células. Encontramos IgG específica para C. trachomatis en el 27 por ciento de las mujeres con síntomas clínicos, en el 40 por ciento de las que concurrieron al control ginecológico, en el 60 por ciento de las que consultaron por esterilidad y en el 10 por ciento de las embarazadas. Con un test de hipótesis para comparar proporciones se demostró que los valores e la presencia de IgG específicas es altamente significativa (p < 0,0001) para las estériles con respecto a las emabarazadas. De la relación del aislamiento de la bacteria con la presencia de IgG específica se formaron 4 grupos de pacientes, 7 de 10 tuvieron aislamiento e IFI positivo, 5 de 8, aislamiento positivo e IFI negativo; 25 de 28 (grupo de embarazadas), aislamiento negativo e IFI positivo y 63 de 76 dieron negativo en las 2 pruebas. El test de McNemar indica que la presencia de IgG tiene un alto grado de significación en las mujeres estériles con respecto a los otros grupos con una p < 0,001. En los neonatos se detectó C. trachomatis por aislamiento en un 20 por ciento, y presencia de IgM específica en un 10 por ciento. En los neonatos, habría un mejor diagnóstico combinando las 2 técnicas. Nuestros resultados sugieren que la detección de la IgG específica no es un criterio suficiente para el diagnóstico, debiendo acompañarse con el aislamiento de la bacteria. Sólo habría presencia de IgG con valores diagnósticos en mujeres estériles con antecedentes de C. trachomatis. Estos resultados señalan la importancia de la detección de C. trachomatis en jóvenes para evitar la infertilidad, y en embarazadas para prevenir la infección neonatal y la posibilidad de nacimientos prematuros y bajo peso al nacer de los niños.