7 research outputs found
Geon black holes and quantum field theory
Black hole spacetimes that are topological geons in the sense of Sorkin can
be constructed by taking a quotient of a stationary black hole that has a
bifurcate Killing horizon. We discuss the geometric properties of these geon
black holes and the Hawking-Unruh effect on them. We in particular show how
correlations in the Hawking-Unruh effect reveal to an exterior observer
features of the geometry that are classically confined to the regions behind
the horizons.Comment: 11 pages. Talk given at the First Mediterranean Conference on
Classical and Quantum Gravity, Kolymbari (Crete, Greece), September 2009.
Dedicated to Rafael Sorkin. v2: typesetting bug fixe
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
Malignancies among children and young people with HIV in Western and Eastern Europe and Thailand
Malignancies among children and young people with HIV in Western and Eastern Europe and Thailand the European Pregnancy and Paediatric Infections Cohort Collaboration (EPPICC) study group
Objectives: Investigate trends over time and predictors of malignancies among children and young people with HIV. Design: Pooled data from 17 cohorts in 15 countries across Europe and Thailand. Methods: Individuals diagnosed with HIV and presenting to paediatric care less than 18 years of age were included. Time at risk began at birth for children with documented vertically acquired HIV, and from first HIV-care visit for others. Children were followed until death, loss-to-follow-up, or last visit in paediatric or adult care (where data after transfer to adult care were available). Rates of reported malignancies were calculated overall and for AIDS-defining malignancies (ADM) and non-AIDS-defining malignancies (NADM) separately. Risk factors for any malignancy were explored using Poisson regression, and for mortality following a malignancy diagnosis using Cox regression. Results: Among 9632 individuals included, 140 (1.5%) were ever diagnosed with a malignancy, of which 112 (80%) were ADM. Overall, the rate of any malignancy was 1.18 per 1000 person-years; the rate of ADM decreased over time whereas the rate of NADM increased. Male sex, being from a European cohort, vertically acquired HIV, current severe immunosuppression, current viral load greater than 400 copies/ml, older age, and, for those not on treatment, earlier calendar year, were risk factors for a malignancy diagnosis. Fifty-eight (41%) individuals with a malignancy died, a median 2.4 months (IQR 0.6-8.8) after malignancy diagnosis. Conclusion: The rate of ADM has declined since widespread availability of combination ART, although of NADM, there was a small increase. Mortality following a malignancy was high, warranting further investigation
Children living with HIV in Europe: do migrants have worse treatment outcomes?
Objectives: To assess the effect of migrant status on treatment outcomes among children living with HIV in Europe. Methods: Children aged < 18 years at the start of antiretroviral therapy (ART) in European paediatric HIV observational cohorts where â„ 5% of children were migrants (defined as born abroad) were included. Three outcomes were considered: (i) severe immunosuppression-for-age; (ii) viraemic viral load (â„ 400 copies/mL) at 1 year after ART initiation; and (iii) AIDS/death after ART initiation. The effect of migrant status was assessed using univariable and multivariable logistic and Cox models. Results: Of 2620 children included across 12 European countries, 56% were migrants. At ART initiation, migrant children were older than domestic-born children (median 6.1 vs. 0.9 years, p < 0.001), with slightly higher proportions being severely immunocompromised (35% vs. 33%) and with active tuberculosis (2% vs. 1%), but a lower proportion with an AIDS diagnosis (14% vs. 19%) (all p < 0.001). At 1 year after beginning ART, a lower proportion of migrant children were viraemic (18% vs. 24%) but there was no difference in multivariable analysis (p = 0.702), and no difference in severe immunosuppression (p = 0.409). However, there was a trend towards higher risk of AIDS/death in migrant children (adjusted hazard ratio = 1.51, 95% confidence interval: 0.96â2.38, p = 0.072). Conclusions: After adjusting for characteristics at ART initiation, migrant children have virological and immunological outcomes at 1 year of ART that are comparable to those who are domestic-born, possibly indicating equity in access to healthcare in Europe. However, there was some evidence of a difference in AIDS-free survival, which warrants further monitoring
Children living with HIV in Europe: do migrants have worse treatment outcomes?
International audienceTo assess the effect of migrant status on treatment outcomes among children living with HIV in Europe