15 research outputs found
Superconducting proximity effect in clean ferromagnetic layers
We investigate superconducting proximity effect in clean ferromagnetic layers
with rough boundaries. The subgap density of states is formed by Andreev bound
states at energies which depend on trajectory length and the ferromagnetic
exchange field. At energies above the gap, the spectrum is governed by resonant
scattering states. The resulting density of states, measurable by tunneling
spectroscopy, exhibits a rich structure, which allows to connect the
theoretical parameters from experiments.Comment: 11 pages, 5 figures (included
The epidemiology of human papillomavirus in HIV-negative and HIV-infected men who have sex with men
This thesis studied the epidemiology and seroepidemiology of human papillomavirus (HPV) among HIV-negative and HIV-infected men who have sex with men (MSM) in Amsterdam, the Netherlands. Anal, penile, and oral HPV prevalence and incidence were high, in particular among HIV-infected MSM. Clearance of anal HPV infection was lower among HIV-infected compared to HIV-negative MSM. HIV infection was strongly associated with HPV infection, independent of sexual behavior and other possible confounders. However, within HIV-infected MSM no association between increasing level of immunosuppression (i.e., low CD4 T-cell count) and HPV infection was observed. Furthermore, HPV seroprevalence was high, especially among MSM with HIV infection or anal HPV infection. In longitudinal analyses incident or persistent anal HPV infections were the main drivers of type-specific HPV seroconversion. HPV seropositivity, however, did not seem to protect adult, sexually active MSM from subsequent type-specific HPV infection. Future research should focus on increasing insight in the effect of HIV-related immunosuppression on HPV infection and sequelae, the function of naturally induced HPV antibodies, and optimizing HPV prevention strategies
Twelve-month incidence and clearance of oral HPV infection in HIV-negative and HIV-infected men who have sex with men: the H2M cohort study
Our aim was to compare the 12-month incidence and clearance of oral high-risk HPV infection between HIV-infected men who have sex with men (MSM) and HIV-negative MSM. MSM aged 18 years or older were recruited in Amsterdam, the Netherlands. Questionnaire data and oral-rinse and gargle samples were collected at baseline, and after 6 and 12 months. HPV DNA was genotyped using the SPF10-PCR & DEIA-LiPA25 system (version 1). Determinants of oral HPV incidence and clearance were explored using Cox and logistic regression analyses respectively. 433 HIV-negative and 290 HIV-infected MSM were included in these analyses. The median follow-up time per participant was 12 months (range 3-15). During follow-up, 114 incident oral high-risk HPV infections were observed. The incidence rate of HPV-16 was 3.5/1000 person-months (PM) in HIV-infected and 0.9/1000 PM in HIV-negative MSM (IRR 4.1; 95% CI 1.3-13.2). The incidence rates of other high-risk HPV types ranged between 1.3-3.5/1000 PM in HIV-infected and 0.0-1.1/1000 PM in HIV-negative MSM. In multivariable analyses, HIV infection (adjusted hazard ratio [aHR] 3.8; 95% CI 2.3-6.2) and a higher number of recent oral sex partners (aHR 2.4 for ≥8 partners compared to ≤2; 95% CI 1.4-4.2) were associated with HPV incidence. Of the 111 baseline oral high-risk infections, 59 (53.2%) were cleared. In multivariable analyses, only a higher number of recent oral sex partners was associated with HPV clearance (adjusted odds ratio 3.4 for ≥8 compared to ≤2 partners; 95% CI 1.3-9.0). The incidence rate of oral high-risk HPV infection was higher in HIV-infected MSM and in those with a higher number of recent oral sex partners. Just over half of the oral high-risk HPV infections at baseline were cleared after 12 months, with a higher likelihood of clearance among MSM reporting higher numbers of recent oral sex partners, but no difference by HIV statu
Characterization of the early cellular immune response induced by HPV vaccines
Introduction: Current human papillomavirus (HPV) vaccines consist of virus-like particles (VLPs) which are based on the L1 protein, but they are produced by different expression systems and use different adjuvants. We performed in-depth immunophenotyping of multiple innate and adaptive immune cells after vaccination with bivalent versus nonavalent HPV vaccines. Method: Twenty pre-menopausal HPV-seronegative women were enrolled and randomized to receive three-doses of either the bivalent or the nonavalent HPV vaccine. Blood samples were collected at multiple time points from baseline up to 7 months after first vaccination. Four extensive EuroFlow flow cytometry antibody panels were used to monitor various immune cell subsets. Additionally, HPV-specific memory B- and T cells were determined by ELISPOT and HPV-specific antibody levels were measured by a VLP-based multiplex immunoassay. Results: In both cohorts, the numbers of plasma cells expanded in the first week after both primary and tertiary vaccination. HPV16 and HPV18-specific antibody levels and memory B and T-cell responses were higher in the bivalent than in the nonavalent vaccinees one month post third vaccination. For HPV31 and HPV45-specific antibody levels this pattern was reversed. Monocytes showed an expansion one day after vaccination in both cohorts but were significantly higher in the bivalent vaccine cohort. Large heterogeneity in responses of the other cell subsets was observed between donors. Conclusion: This pilot study showed a consistent response of monocytes and plasma cells after vaccination and a considerable variation in other circulating immune cells in both types of HPV vaccines between donors.</p
Characterization of the early cellular immune response induced by HPV vaccines
IntroductionCurrent human papillomavirus (HPV) vaccines consist of virus-like particles (VLPs) which are based on the L1 protein, but they are produced by different expression systems and use different adjuvants. We performed in-depth immunophenotyping of multiple innate and adaptive immune cells after vaccination with bivalent versus nonavalent HPV vaccines. MethodTwenty pre-menopausal HPV-seronegative women were enrolled and randomized to receive three-doses of either the bivalent or the nonavalent HPV vaccine. Blood samples were collected at multiple time points from baseline up to 7 months after first vaccination. Four extensive EuroFlow flow cytometry antibody panels were used to monitor various immune cell subsets. Additionally, HPV-specific memory B- and T cells were determined by ELISPOT and HPV-specific antibody levels were measured by a VLP-based multiplex immunoassay. ResultsIn both cohorts, the numbers of plasma cells expanded in the first week after both primary and tertiary vaccination. HPV16 and HPV18-specific antibody levels and memory B and T-cell responses were higher in the bivalent than in the nonavalent vaccinees one month post third vaccination. For HPV31 and HPV45-specific antibody levels this pattern was reversed. Monocytes showed an expansion one day after vaccination in both cohorts but were significantly higher in the bivalent vaccine cohort. Large heterogeneity in responses of the other cell subsets was observed between donors. ConclusionThis pilot study showed a consistent response of monocytes and plasma cells after vaccination and a considerable variation in other circulating immune cells in both types of HPV vaccines between donors.Experimental cancer immunology and therap