Initiation of an anal cancer screening in HIV+MSM: results of cytology, biopsy and determination of risk factors

Incidence of anal cancer is increasing and risk of anal cancer is higher in MSM, especially if they are HIV+. European guidelines for treatment of HIV-infected adults recommend anal cancer screening by digital rectal exam±Pap test with anuscopy if Pap test is abnormal. A systematic anal cancer screening in HIV+MSM with anal cytology (Pap smears) was established in June 2011 in our reference centre in Brussels. If anal cytology was abnormal, high-resolution anuscopy (HRA) with biopsy was performed. 353 MSM HIV+were screened by anal smears between June 2011 and May 2012. 90% were Caucasians, median age was 44.5 years, 83% were on HAART and 74% had an undetectable viral load, median CD4 was 632/µl and 33% had a nadir CD4<200. Thirty-three (9.3%) were excluded because of poor quality. Cytology was abnormal in 46% of the 320 remaining patients: high-grade squamous intraepithelial lesion (HSIL) 3%, low-grade squamous intraepithelial lesion (LSIL) 24%, atypical squamous cells of undetermined significance (ASC-US) 16%, and atypical squamous cells / cannot rule out a high-grade lesion (ASC-H) 3%. Viral load (VL) was more frequently undetectable (82% vs 64%, p=0.0003) and median duration of HAART was longer (111 vs 61 months, p=0.0145) in patients with normal cytology. 80 HRA with biopsies have been performed. 12.5% were normal, 44% showed anal intraepithelial neoplasia (AIN) 1, 24% AIN 2 and 19% AIN 3. For this analysis, high-grade AIN (2 and 3) were put together (AIN 2+). Among patients with AIN 2+(n=33), cytology had showed 8 (24%) ASC-US, 3 (9%) ASC-H, 19 (57%) LSIL, 3 (9%) HSIL. When patients with normal cytology or normal biopsy and patients with AIN 2+were compared, the only significant risk factor found for AIN 2+was a nadir CD4<100/µl (32% of the patients with AIN 2+vs 14% in patients with normal smear, p=0.0073). Anal precancerous lesions are frequent and at different stages. Among 46% abnormal cytology, 87% had abnormal biopsy including half AIN 2+.Cytology±biopsy is the only way to detect those lesions and should be performed systematically in HIV+MSM. Risk factor for AIN2+was a nadir CD4<100/µl. A normal cytology was associated with an undetectable VL and a longer duration of HAART. Those results provide further argument for early initiation of HAART

Snow spectral albedo at Summit, Greenland: measurements and numerical simulations based on physical and chemical properties of the snowpack

The broadband albedo of surface snow is determined both by the near-surface profile of the physical and chemical properties of the snowpack and by the spectral and angular characteristics of the incident solar radiation. Simultaneous measurements of the physical and chemical properties of snow were carried out at Summit Camp, Greenland (72°36´ N, 38°25´ W, 3210 m a.s.l.) in May and June 2011, along with spectral albedo measurements. One of the main objectives of the field campaign was to test our ability to predict snow spectral albedo by comparing the measured albedo to the albedo calculated with a radiative transfer model, using measured snow physical and chemical properties. To achieve this goal, we made daily measurements of the snow spectral albedo in the range 350–2200 nm and recorded snow stratigraphic information down to roughly 80 cm. The snow specific surface area (SSA) was measured using the DUFISSS instrument (DUal Frequency Integrating Sphere for Snow SSA measurement, Gallet et al., 2009). Samples were also collected for chemical analyses including black carbon (BC) and dust, to evaluate the impact of light absorbing particulate matter in snow. This is one of the most comprehensive albedo-related data sets combining chemical analysis, snow physical properties and spectral albedo measurements obtained in a polar environment. The surface albedo was calculated from density, SSA, BC and dust profiles using the DISORT model (DIScrete Ordinate Radiative Transfer, Stamnes et al., 1988) and compared to the measured values. Results indicate that the energy absorbed by the snowpack through the whole spectrum considered can be inferred within 1.10%. This accuracy is only slightly better than that which can be obtained considering pure snow, meaning that the impact of impurities on the snow albedo is small at Summit. In the near infrared, minor deviations in albedo up to 0.014 can be due to the accuracy of radiation and SSA measurements and to the surface roughness, whereas deviations up to 0.05 can be explained by the spatial heterogeneity of the snowpack at small scales, the assumption of spherical snow grains made for DISORT simulations and the vertical resolution of measurements of surface layer physical properties. At 1430 and around 1800 nm the discrepancies are larger and independent of the snow properties; we propose that they are due to errors in the ice refractive index at these wavelengths. This work contributes to the development of physically based albedo schemes in detailed snowpack models, and to the improvement of retrieval algorithms for estimating snow properties from remote sensing data

Climate driven life histories: the case of the Mediterranean Storm petrel

Seabirds are affected by changes in the marine ecosystem. The influence of climatic factors on marine food webs can be reflected in long-term seabird population changes. We modelled the survival and recruitment of the Mediterranean storm petrel (Hydrobates pelagicus melitensis) using a 21-year mark-recapture dataset involving almost 5000 birds. We demonstrated a strong influence of prebreeding climatic conditions on recruitment age and of rainfall and breeding period conditions on juvenile survival. The results suggest that the juvenile survival rate of the Mediterranean subspecies may not be negatively affected by the predicted features of climate change, i.e., warmer summers and lower rainfall. Based on considerations of winter conditions in different parts of the Mediterranean, we were able to draw inferences about the wintering areas of the species for the first time

Generation and characterization of a defective HIV-1 Virus as an immunogen for a therapeutic vaccine

BACKGROUND: The generation of new immunogens able to elicit strong specific immune responses remains a major challenge in the attempts to obtain a prophylactic or therapeutic vaccine against HIV/AIDS. We designed and constructed a defective recombinant virus based on the HIV-1 genome generating infective but non-replicative virions able to elicit broad and strong cellular immune responses in HIV-1 seropositive individuals. RESULTS: Viral particles were generated through transient transfection in producer cells (293-T) of a full length HIV-1 DNA carrying a deletion of 892 base pairs (bp) in the pol gene encompassing the sequence that codes for the reverse transcriptase (NL4-3/ΔRT clone). The viral particles generated were able to enter target cells, but due to the absence of reverse transcriptase no replication was detected. The immunogenic capacity of these particles was assessed by ELISPOT to determine γ-interferon production in a cohort of 69 chronic asymptomatic HIV-1 seropositive individuals. Surprisingly, defective particles produced from NL4-3/ΔRT triggered stronger cellular responses than wild-type HIV-1 viruses inactivated with Aldrithiol-2 (AT-2) and in a larger proportion of individuals (55% versus 23% seropositive individuals tested). Electron microscopy showed that NL4-3/ΔRT virions display immature morphology. Interestingly, wild-type viruses treated with Amprenavir (APV) to induce defective core maturation also induced stronger responses than the same viral particles generated in the absence of protease inhibitors. CONCLUSIONS: We propose that immature HIV-1 virions generated from NL4-3/ΔRT viral clones may represent new prototypes of immunogens with a safer profile and stronger capacity to induce cellular immune responses than wild-type inactivated viral particles.This study was supported by grants FIS PI050265, FIS PI040503, FIS PI070291, FIS Intrasalud 080752, FIS PS09/01297, FIS PI10/02984, SAF2006-26667-E, FIT 09-010-205-9, FIPSE 36780/08, Fundación Mútua Madrileña, TRA-094, EC10-153, ISCIII-RETIC RD06/0006, HIVACAT–HIV Development Program in Catalonia, FIPSE 36630/07, UE Program Health 2009 CHAARM. Spanish Health Institute Carlos III (ISCIII) and the Health Department of the Catalan Government (Generalitat de Catalunya). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

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