BackgroundHuman papillomavirus (HPV) currently represents an important risk factor for cancer development and infertility in humans. Whilst binding of HPV to spermatozoa has been associated with male infertility, an investigation about the presence of HPV-DNA in non-spermatozoal semen cells is lacking. Previous findings documented the presence of HPV in peripheral blood leukocytes. The aim of this study was to investigate the expression of HPV markers in semen and blood leukocytes during HPV-16 infection.MethodsA total of 32 subjects, 16 patients affected by HPV-16 semen infection and 16 controls, were evaluated in our andrological centre and enrolled in the study. Semen non-spermatozoal cells from all subjects were isolated and evaluated for the expression of HPV-16 markers (DNA and L1, E6 proteins) and further characterized for their molecular phenotype. Analogue determination was performed on peripheral blood mononuclear cells.ResultsThe presence of HPV-DNA by FISH analysis in a round cell population from semen, confirmed to be CD45+ leukocytes, was observed. These HPV-DNA containing-cells also displayed HPV-16-E6 and HPV-16-L1 viral proteins and, upon further investigation, were found to be CD20+ and CD56+, likely phenotypes of B cells and natural killer cells (NK) respectively. In 25% of the patient group, a very small population of peripheral blood mononuclear cells was found to be positive for HPV-DNA via FISH. These cells displayed the CD20+ and CD56+ phenotype alike. None of the control subjects displayed HPV-DNA in either semen or peripheral blood.ConclusionConsidering the role of CD20+ and CD56+ cell populations in the antiviral immune response, the detection of HPV markers on leukocytes may reflect the presence of virus particles within the endosomal compartment. However, the presence of HPV markers in circulating mononuclear cells raise concerns about the risk of developing cancers to distal organs.
Botulinum neurotoxins type D and F are zincendopeptidases with a unique specificity for VAMP/synaptobrevin, an essential component of the exocytosis apparatus. VAMP contains two copies of a nine residue motif, termed VI and V2, which are determinants of the interaction with tetanus and botulinum B and G neurotoxins. Here, we show that VI plays a major role in VAMP recognition by botulinum neurotoxins D and F and that V2 is also involved in F binding. Site-directed mutagenesis of VI and V2 indicates that different residues are the determinants of the VAMP interaction with the two endopeptidases. The study of the VAMP-neurotoxins interaction suggest a pairing of the VI and V2 segments.
Classic nephropathic or infantile cystinosis (NC) is an autosomal recessive disorder; the gene coding for the integral membrane protein cystinosin, which is responsible for membrane transport of cystine (CTNS), was cloned. Mutation analysis of the CTNS gene of Caucasian patients revealed a common 57-kb deletion, and several other mutations spread throughout the entire gene. In the present study, we report the CTNS mutations identified in 42 of 46 Italian families with NC. The percentage of mutations characterized in this study is 86%. The mutational spectrum of the Italian population is different from that of populations of North European origin: the 57-kb deletion is present in a lower percentage, while the splicing mutations represent 30% of mutation detected in our sample. In all, six novel mutations have been identified, and the origin of one recurrent mutation has been traced.
KRAS somatic mutations are found in 30-40% of colorectal cancer (CRC). Seven mutations in codons 12 and 13 of KRAS (95% of the observed human mutations) preclude the efficacy of anti-EGFR therapy for the treatment of CRC. Assessment of KRAS mutational status has become a standard procedure in the management of patients with CRC. Technically, KRAS mutation testing can be performed with different methods, characterized by distinct sensitivities and specificities. The present study analyzed KRAS in 182 CRC histological samples by using direct sequencing and a new kit based on a Real-Time Sequence-Specific Primers-PCR technology. The kit allowed to recover as positive 17 samples that were negative or unclear by sequencing, with a recovery rate equal to 13.82%. This study proposes a fast, sensitive, and high-throughput system to identify such seven described mutations of KRAS gene in CRC samples.
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