ABSTRACT
Infection with high risk Human papillomavirus (HR-HPV) is necessary but not sufficient to cause cervical carcinoma. This study explored whether multiple HR-HPV or coinfection with Epstein-Barr virus (EBV) influence the integration status of HPV16 genome. The presence and typing of HPV in a series of 125 cervical specimens were assessed by polymerase chain reaction (PCR) using the specific primers for the HPV L1 region. As for EBV infection, the viral EBNA1 gene was used for its detection through PCR amplification. Disruption of the HPV E2 gene was assessed by amplification of the entire E2 gene with single set of primers, while E2 transcripts were evaluated by a reverse transcription PCR method (RT-PCR). The overall prevalence of HPVDNA was of 81.8% in cervical cancers versus 26.9% in benign lesions. In HPV positive cases, HPV16 and HPV18 were the most prevalent types, followed by HPV types 33, 31. EBV EBNA1 prevalence was statistically more frequent in cervical carcinomas than in benign lesions (29.5%, vs 9.6%; P=0.01). No viral infection was detected in healthy control women. The uninterrupted E2 gene was correlated with the presence of E2 transcripts originating from the HPV episomal forms. It was observed that integration was more common in HPV18 and EBV coinfection. The presence of EBV caused a five-fold [OR= 5; CI= 1.15-21.8; P = 0.04] increase in the risk of HPV16 genome integration in the host genome. This study indicates that EBV infection is acting as a cofactor for induction of cervical cancer by favoring HPVDNA integration.
Subject(s)
Humans , Gene Amplification , Genome , Herpesviridae Infections , /genetics , Uterine Cervical Neoplasms/genetics , Papillomavirus Infections , /genetics , Risk Factors , Reverse Transcriptase Polymerase Chain Reaction/methods , Polymerase Chain Reaction/methods , Electrophoresis , Methods , Patients , PrevalenceABSTRACT
Beja is an agricultural area in northwest Tunisia. It contributes to national needs by offering cereals and milk to the market for human and animal consumption. A small number of studies on mycotoxin occurrence in feedstuffs and raw milk from lactating dairy cows in this region are available. Therefore, 226 samples were collected from farms and local markets during November 2008 until April 2010. Samples consisted of 112 raw cow milk, 56 blood from lactating cows and 58 feed destined for dairy cows. Plasma and feed were analysed for aflatoxin B1 (AFB1). Milk samples were analysed for aflatoxin M1 (AFM1). All samples were treated using a simultaneous methanolic-aqueous extraction, followed by immunoaffinity column clean-ups and were investigated by competitive enzyme-linked immunoabsorbent assay (ELISA). Recoveries were 80%-95% and 81%-92% for AFB1 and AFM1, respectively, while the limit of detection (LOD) was 0.01 µg/kg or µg/l for both mycotoxins. Results revealed the presence of AFB1 in 84.4% of the feed samples (mean 18.7 ± 1.4 µg/kg), and 39.2% of the plasma-examined samples (median 7.1 ± 1.0 µg/l) were found to be contaminated at levels higher than the Tunisian and the European Union (EU) limit for dairy animals, which are 20 and 5 µg/kg in animal feed, respectively. AFM1 was detected in 60.7% of the cow raw milk samples examined (median 13.6 ± 1.4 µg/l). Contaminated levels were higher than the EU limit of 0.05 µg/l. It was concluded that more precaution should be taken on hygiene controls in order to prevent fungal contamination.
Subject(s)
Aflatoxin B1/analysis , Aflatoxin M1/analysis , Animal Feed/analysis , Carcinogens/analysis , Food Contamination , Lactation/blood , Milk/chemistry , Aflatoxin B1/blood , Analytic Sample Preparation Methods/veterinary , Animal Feed/standards , Animals , Cattle , Chromatography, Affinity/veterinary , Dairying , Enzyme-Linked Immunosorbent Assay/veterinary , European Union , Female , Food Inspection , Guideline Adherence , Health Policy , Health Promotion , Humans , Milk/economics , TunisiaABSTRACT
Infection with high risk Human papillomavirus (HR-HPV) is necessary but not sufficient to cause cervical carcinoma. This study explored whether multiple HR-HPV or coinfection with Epstein-Barr virus (EBV) influence the integration status of HPV16 genome. The presence and typing of HPV in a series of 125 cervical specimens were assessed by polymerase chain reaction (PCR) using the specific primers for the HPV L1 region. As for EBV infection, the viral EBNA1 gene was used for its detection through PCR amplification. Disruption of the HPV E2 gene was assessed by amplification of the entire E2 gene with single set of primers, while E2 transcripts were evaluated by a reverse transcription PCR method (RT-PCR). The overall prevalence of HPVDNA was of 81.8% in cervical cancers versus 26.9% in benign lesions. In HPV positive cases, HPV16 and HPV18 were the most prevalent types, followed by HPV types 33, 31. EBV EBNA1 prevalence was statistically more frequent in cervical carcinomas than in benign lesions (29.5%, vs 9.6%; P=0.01). No viral infection was detected in healthy control women. The uninterrupted E2 gene was correlated with the presence of E2 transcripts originating from the HPV episomal forms. It was observed that integration was more common in HPV18 and EBV coinfection. The presence of EBV caused a five-fold [OR= 5; CI= 1.15-21.8; P = 0.04] increase in the risk of HPV16 genome integration in the host genome. This study indicates that EBV infection is acting as a cofactor for induction of cervical cancer by favoring HPVDNA integration.
