Identification of Genetic Variants of Human Papillomavirus in a Group of Mexican HIV/AIDS Patients and Their Possible Association with Cervical Cancer.

Infections caused by the human immunodeficiency virus (HIV) and human papillomavirus (HPV) cause thousands of deaths worldwide each year. So far, there has been no consensus on whether there is a direct relationship between the incidence of neoplasms and the immunosuppression caused by HIV that could help understand if coinfection increases the likelihood of cervical cancer. The objective of the study was to identify the presence of genetic variants of HPV in a group of HIV-positive women and their possible association with cervical cancer. Cervical samples were taken from HIV-positive patients for cytological analysis to identify the HPV genotype by polymerase chain reaction (PCR) and sequencing. The most prevalent L1 capsid protein mutations in the HPV genotype were analyzed in silico. Various types of HPV were identified, both high-risk (HR) and low-risk (LR). The most prevalent genotype was HPV51. Analysis of the L1 gene sequences of HPV51 isolates showed nucleotide variations. Of the samples analyzed in Puebla, Mexico, HPV51 had the highest incidence (17.5%, 7/40). Different mutations, which could be used as population markers, were detected in this area, and they have not been reported in the L1 databases for HPV51 in Mexico. Genotypes 6, 14, 86, 87, 89, and 91, not detected or reported in samples from patients with HPV in Mexico, were also identified. Data from the population analyzed suggest no direct relationship between HIV immunosuppression and cervical cancer, regardless of the high- or low-risk HPV genotype. Furthermore, it is possible to develop regional population markers for the detection of HPV based on the mutations that occur in the sequence of nucleotides analyzed.

Absence of human papillomavirus sequences in epithelial breast cancer in a Mexican female population.

The role of human papillomavirus (HPV) in breast cancer is controversial. We evaluated 118 breast carcinomas and two paraffin-embedded tissues of lesions of the nipple of Mexican patients for HPV sequences. No carcinoma sample exhibited koilocytosis, in contrast to lesions of the nipple. We subjected purified DNAs to PCR employing two HPV16/E6 or GP5/6 primer set oligonucleotides. Results showed that HPV DNA sequences were absent in the breast tissues. Absence of HPV in breast carcinoma failed to support an association between HPV infection and this carcinoma.

[The PQQ-dehydrogenases. A novel example of bacterial quinoproteins]. / Las PQQ-deshidrogenasas. Un novedoso ejemplo de quinoproteínas bacterianas.

The word "quinoprotein" describes four groups of different enzymes which have cofactors containing o-quinones. Pyrrolo-quinoline quinone (PQQ) is not covalently attached. PQQ is the cofactor of several quinoprotein bacterial dehydrogenases including glucose dehydrogenase (G-DH), alcohol dehydrogenase (A-DH) and aldehyde dehydrogenase (AL-DH). These dehydrogenases are located in the periplasm of Gram-negative bacteria. This report summarises the structural properties of quinoprotein dehydrogenases, such as the biological functions and biotechnological aspects more important.