66 research outputs found
Construction and characterisation of infectious recombinant HIV-1 clones containing CTL epitopes from structural proteins in Nef.
In this study the construction is described of HIV-1 molecular clones in which CTL epitopes from RT or Env late proteins were inserted into the Nef early protein. The ectopic epitopes were efficiently processed from the recombinant Nef proteins, were recognized by their cognate CTL in cytolytic assays, and did not perturb virus replication or viral protein expression in vitro. These recombinant viruses will therefore be an important tool in studying the effect of distinct epitope expression kinetics on the efficiency of CTL-mediated suppression of HIV-1 replication
Impact of FDG PET on the management of TBC treatment
The AIM: of this study is to assess the potential
impact of double-phase FDG PET versus routine
staging in HIV-negative patients suffering
from tuberculosis. PATIENTS, METHODS: 16 consecutive
patients suffering from tuberculosis underwent contrast-enhanced CT and double-phase FDG PET imaging (45 min, 120 min). Early (E) and delayed (D) SUVmax values were determined for all identified lesions
and % change in SUV calculated (ΔSUV).
RESULTS: Seven patients presented with lung lesions on PET as well as CT (mean SUVmaxE 8.2, mean SUVmaxD 11.1, (p = 0.002), ΔSUV
35%. In two patients, lesions were judged as non-active on CT. In nine patients, 18 sites of LN involvement were identified on both early
and delayed FDG PET images (mean SUVmaxE 6.3, mean SUVmaxD 7.9, (p = 0.0001), ΔSUV: 25%). 9 out of 18 sites of LN involvement, occurring in five patients, were missed on CT. In four of these five patients, sites of LN involvement were the only sites of
extra-pulmonary involvement identified. In 6 out of 16 patients, pleural involvement was identified, respectively in 5 on FDG PET and in
6 on CT imaging (mean SUVmaxE 1.3, mean SUVmaxD 1.7, (p = 0.06), ΔSUV 21%). In 4 patients, osseous involvement was identified by
both FDG PET and CT (mean SUVmaxE 7.2, mean SUVmaxD 10.7, (p = 0,06), ΔSUV 45%).
Finally, in 3 patients, joint involvement was
identified on both FDG PET as well as on CT imaging
(mean SUVmaxE 4.7, mean SUVmaxD 5.2, ΔSUV 23%). FDG PET did not identify CTadditional sites of involvement that would have resulted in a prolonged treatment.
CONCLUSION: In HIV-negative patients suffering from tuberculosis, FDG PET images suggested a more extensive involvement by Mycobacterium tuberculosis when compared to contrast
enhanced CT.Ziel dieser Studie ist die Beurteilung eines möglichen
Einflusses der 2-Phasen-FDG-PET im Vergleich
zum Routine-Staging bei HIV-negativen
Patienten mit Tuberkulose. PATIENTEN, METHODEN:
Bei 16 aufeinanderfolgenden Patienten
mit Tuberkulose wurden ein kontrastverstärktes
CT sowie eine 2-Phasen-FDG-PET (45 min,
120 min) durchgeführt. Frühe (E) und späte (D)
SUVmax-Werte wurden für alle dargestellten Läsionen bestimmt; die prozentuale Veränderung
der SUV (ΔSUV) wurde berechnet. ERGEBNISSE:
Bei sieben Patienten zeigten sich pulmonale
Herde sowohl in der PET als auch im
CT (mittlere SUVmaxE 8,2, mittlere SUVmaxD
11,1, (p = 0,002), ΔSUV 35%). Bei zwei Patienten
wurden die Läsionen im CT als nicht
aktiv beurteilt. Bei neun Patienten wurde sowohl
in den frühen als auch in den späten
FDG-PET-Aufnahmen ein Lymphknotenbefall
an 18 Stellen identifiziert (mittlere SUVmaxE
6,3, mittlere SUVmaxD 7,9, (p = 0,0001),
ΔSUV 25%). Bei fünf Patienten fehlten im CT 9
der 18 befallenen Lymphknoten. Bei vier dieser
fünf Patienten stellte der Lymphknotenbefall
die einzige extrapulmonale Beteiligung
dar. Bei 6/16 Patienten wurde eine pleurale
Beteiligung festgestellt, bei 5 in der FDG-PET
bzw. bei 6 im CT (mittlere SUVmaxE 1,3, mittlere
SUVmaxD 1,7, (p = 0,06), ΔSUV 21 %).
Bei 4 Patienten wurde eine Knochenbeteiligung
sowohl in der FDG-PET als auch im CT
diagnostiziert (mittlere SUVmaxE 7,2, mittlere
SUVmaxD 10,7, (p = 0,06), ΔSUV 45%).
Schließlich wurde bei 3 Patienten ein Befall
der Gelenke sowohl in der FDG-PET als auch
im CT festgestellt (mittlere SUVmaxE 4,7,
mittlere SUVmaxD 5,2, ΔSUV 23%). In der
FDG-PET konnte kein über das CT hinausgehender
Befall festgestellt werden, der zu
längerer Behandlungsdauer geführt hätte.
SCHLUSSFOLGERUNG: Bei HIV-negativen Patienten
mit Tuberkulose können die FDG-PET-Aufnahmen
einen ausgedehnteren Befall mit Mycobacterium
tuberculosis vermuten lassen als
das kontrastverstärkte CT
Assessment of epidemic projections using recent HIV survey data in South Africa: a validation analysis of ten mathematical models of HIV epidemiology in the antiretroviral therapy era
Background Mathematical models are widely used to simulate the eff ects of interventions to control HIV and to
project future epidemiological trends and resource needs. We aimed to validate past model projections against data
from a large household survey done in South Africa in 2012.
Methods We compared ten model projections of HIV prevalence, HIV incidence, and antiretroviral therapy (ART)
coverage for South Africa with estimates from national household survey data from 2012. Model projections for 2012
were made before the publication of the 2012 household survey. We compared adult (age 15–49 years) HIV prevalence
in 2012, the change in prevalence between 2008 and 2012, and prevalence, incidence, and ART coverage by sex and by
age groups between model projections and the 2012 household survey.
Findings All models projected lower prevalence estimates for 2012 than the survey estimate (18·8%), with eight
models’ central projections being below the survey 95% CI (17·5–20·3). Eight models projected that HIV prevalence
would remain unchanged (n=5) or decline (n=3) between 2008 and 2012, whereas prevalence estimates from the
household surveys increased from 16·9% in 2008 to 18·8% in 2012 (diff erence 1·9, 95% CI –0·1 to 3·9). Model
projections accurately predicted the 1·6 percentage point prevalence decline (95% CI –0·3 to 3·5) in young adults
aged 15–24 years, and the 2·2 percentage point (0·5 to 3·9) increase in those aged 50 years and older. Models
accurately represented the number of adults on ART in 2012; six of ten models were within the survey 95% CI of
1·54–2·12 million. However, the diff erential ART coverage between women and men was not fully captured; all
model projections of the sex ratio of women to men on ART were lower than the survey estimate of 2·22 (95% CI
1·73–2·71).
Interpretation Projections for overall declines in HIV epidemics during the ART era might have been optimistic.
Future treatment and HIV prevention needs might be greater than previously forecasted. Additional data about
service provision for HIV care could help inform more accurate projections
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HIV Treatment as Prevention: Systematic Comparison of Mathematical Models of the Potential Impact of Antiretroviral Therapy on HIV Incidence in South Africa
Background: Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across models is challenging because models have addressed slightly different questions and have reported different outcome metrics. This study compares the predictions of several mathematical models simulating the same ART intervention programmes to determine the extent to which models agree about the epidemiological impact of expanded ART. Methods and Findings: Twelve independent mathematical models evaluated a set of standardised ART intervention scenarios in South Africa and reported a common set of outputs. Intervention scenarios systematically varied the CD4 count threshold for treatment eligibility, access to treatment, and programme retention. For a scenario in which 80% of HIV-infected individuals start treatment on average 1 y after their CD4 count drops below 350 cells/µl and 85% remain on treatment after 3 y, the models projected that HIV incidence would be 35% to 54% lower 8 y after the introduction of ART, compared to a counterfactual scenario in which there is no ART. More variation existed in the estimated long-term (38 y) reductions in incidence. The impact of optimistic interventions including immediate ART initiation varied widely across models, maintaining substantial uncertainty about the theoretical prospect for elimination of HIV from the population using ART alone over the next four decades. The number of person-years of ART per infection averted over 8 y ranged between 5.8 and 18.7. Considering the actual scale-up of ART in South Africa, seven models estimated that current HIV incidence is 17% to 32% lower than it would have been in the absence of ART. Differences between model assumptions about CD4 decline and HIV transmissibility over the course of infection explained only a modest amount of the variation in model results. Conclusions: Mathematical models evaluating the impact of ART vary substantially in structure, complexity, and parameter choices, but all suggest that ART, at high levels of access and with high adherence, has the potential to substantially reduce new HIV infections. There was broad agreement regarding the short-term epidemiologic impact of ambitious treatment scale-up, but more variation in longer term projections and in the efficiency with which treatment can reduce new infections. Differences between model predictions could not be explained by differences in model structure or parameterization that were hypothesized to affect intervention impact
Mitchell-Riley Syndrome : Improving Clinical Outcomes and Searching for Functional Impact of RFX-6 Mutations
Aims/HypothesisCaused by biallelic mutations of the gene encoding the transcription factor RFX6, the rare Mitchell-Riley syndrome (MRS) comprises neonatal diabetes, pancreatic hypoplasia, gallbladder agenesis or hypoplasia, duodenal atresia, and severe chronic diarrhea. So far, sixteen cases have been reported, all with a poor prognosis. This study discusses the multidisciplinary intensive clinical management of 4 new cases of MRS that survived over the first 2 years of life. Moreover, it demonstrates how the mutations impair the RFX6 function. MethodsClinical records were analyzed and described in detail. The functional impact of two RFX6(R181W) and RFX6(V506G) variants was assessed by measuring their ability to transactivate insulin transcription and genes that encode the L-type calcium channels required for normal pancreatic beta-cell function. ResultsAll four patients were small for gestational age (SGA) and prenatally diagnosed with duodenal atresia. They presented with neonatal diabetes early in life and were treated with intravenous insulin therapy before switching to subcutaneous insulin pump therapy. All patients faced recurrent hypoglycemic episodes, exacerbated when parenteral nutrition (PN) was disconnected. A sensor-augmented insulin pump therapy with a predictive low-glucose suspension system was installed with good results. One patient had a homozygous c.1517T>G (p.Val506Gly) mutation, two patients had a homozygous p.Arg181Trp mutation, and one patient presented with new compound heterozygosity. The RFX6(V506G) and RFX6(R181W) mutations failed to transactivate the expression of insulin and genes that encode L-type calcium channel subunits required for normal pancreatic beta-cell function. Conclusions/InterpretationMultidisciplinary and intensive disease management improved the clinical outcomes in four patients with MRS, including adjustment of parenteral/oral nutrition progression and advanced diabetes technologies. A better understanding of RFX6 function, in both intestine and pancreas cells, may break ground in new therapies, particularly regarding the use of drugs that modulate the enteroendocrine system.Peer reviewe
Health benefits, costs, and cost-effectiveness of earlier eligibility for adult antiretroviral therapy and expanded treatment coverage: a combined analysis of 12 mathematical models.
BACKGROUND: New WHO guidelines recommend ART initiation for HIV-positive persons with CD4 cell counts ≤500 cells/µL, a higher threshold than was previously recommended. Country decision makers must consider whether to further expand ART eligibility accordingly. METHODS: We used multiple independent mathematical models in four settings-South Africa, Zambia, India, and Vietnam-to evaluate the potential health impact, costs, and cost-effectiveness of different adult ART eligibility criteria under scenarios of current and expanded treatment coverage, with results projected over 20 years. Analyses considered extending eligibility to include individuals with CD4 ≤500 cells/µL or all HIV-positive adults, compared to the previous recommendation of initiation with CD4 ≤350 cells/µL. We assessed costs from a health system perspective, and calculated the incremental cost per DALY averted (/DALY was less than the country's per capita gross domestic product (GDP; South Africa: 1425, India: 1407) and 'cost-effective' if 237 to 749/DALY. Results were similar in scenarios with substantially expanded treatment access and for expanding eligibility to all HIV-positive adults. Expanding treatment coverage in the general population was therefore found to be cost-effective. In India, eligibility for all HIV-positive persons ranged from 241/DALY and in Vietnam eligibility for CD4 ≤500 cells/µL cost $290/DALY. In concentrated epidemics, expanded access among key populations was also cost-effective. INTERPRETATION: Earlier ART eligibility is estimated to be very cost-effective in low- and middle-income settings, although these questions should be revisited as further information becomes available. Scaling-up ART should be considered among other high-priority health interventions competing for health budgets. FUNDING: The Bill and Melinda Gates Foundation and World Health Organization
Assessment of epidemic projections using recent HIV survey data in South Africa: A validation analysis of ten mathematical models of HIV epidemiology in the antiretroviral therapy era
Background: Mathematical models are widely used to simulate the effects of interventions to control HIV and to project future epidemiological trends and resource needs. We aimed to validate past model projections against data from a large household survey done in South Africa in 2012. Methods: We compared ten model projections of HIV prevalence, HIV incidence, and antiretroviral therapy (ART) coverage for South Africa with estimates from national household survey data from 2012. Model projections for 2012 were made before the publication of the 2012 household survey. We compared adult (age 15-49 years) HIV prevalence in 2012, the change in prevalence between 2008 and 2012, and prevalence, incidence, and ART coverage by sex and by age groups between model projections and the 2012 household survey. Findings: All models projected lower prevalence estimates for 2012 than the survey estimate (18·8%), with eight models' central projections being below the survey 95% CI (17·5-20·3). Eight models projected that HIV prevalence would remain unchanged (n=5) or decline (n=3) between 2008 and 2012, whereas prevalence estimates from the household surveys increased from 16·9% in 2008 to 18·8% in 2012 (difference 1·9, 95% CI -0·1 to 3·9). Model projections accurately predicted the 1·6 percentage point prevalence decline (95% CI -0·3 to 3·5) in young adults aged 15-24 years, and the 2·2 percentage point (0·5 to 3·9) increase in those aged 50 years and older. Models accurately represented the number of adults on ART in 2012; six of ten models were within the survey 95% CI of 1·54-2·12 million. However, the differential ART coverage between women and men was not fully captured; all model projections of the sex ratio of women to men on ART were lower than the survey estimate of 2·22 (95% CI 1·73-2·71). Interpretation: Projections for overall declines in HIV epidemics during the ART era might have been optimistic. Future treatment and HIV prevention needs might be greater than previously forecasted. Additional data about service provision for HIV care could help inform more accurate projections. Funding: Bill & Melinda Gates Foundation
Réorganisation de l'activation cérébrale au décours d'accidents vasculaires ischémiques sous-corticaux (corrélation à la récupération clinique)
TOULOUSE3-BU Santé-Centrale (315552105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Monostatic Radar time response for the electromagnetic scattering from a measured rough surface
International audienceThis paper computes the monostatic Radar frequency and time responses of the electromagnetic field scattered by a 1D profile of a natural soil. The rough surface profile was measured with a profilometer which uses a stylus to measure the variations of the heights on the ground of a fallow land. Then, from this experimental surface, the electromagnetic response is calculated from the rigorous Method of Moments (MoM) for moderate incidence angles and by considering a Barker code as the input signal
Monostatic Radar time response for the electromagnetic scattering from a measured rough surface
International audienceThis paper computes the monostatic Radar frequency and time responses of the electromagnetic field scattered by a 1D profile of a natural soil. The rough surface profile was measured with a profilometer which uses a stylus to measure the variations of the heights on the ground of a fallow land. Then, from this experimental surface, the electromagnetic response is calculated from the rigorous Method of Moments (MoM) for moderate incidence angles and by considering a Barker code as the input signal
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