73 research outputs found
Dynamics and dispensability of variant-specific histone H1 Lys-26/Ser-27 and Thr-165 post-translational modifications
Jean-Michel Terme et al.In mammals, the linker histone H1, involved in DNA packaging into chromatin, is represented by a family of variants. H1 tails undergo post-translational modifications (PTMs) that can be detected by mass spectrometry. We developed antibodies to analyze several of these as yet unexplored PTMs including the combination of H1.4 K26 acetylation or trimethylation and S27 phosphorylation. H1.2-T165 phosphorylation was detected at S and G2/M phases of the cell cycle and was dispensable for chromatin binding and cell proliferation; while the H1.4-K26 residue was essential for proper cell cycle progression. We conclude that histone H1 PTMs are dynamic over the cell cycle and that the recognition of modified lysines may be affected by phosphorylation of adjacent residues. © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.This work was supported by the Spanish Ministry of Science and Innovation (MICINN) and European Regional Development Fund (Grant BFU2011-23057 to A.J., and Grant BFU2008-00460 to P.S.), and by the Regional Government of Catalonia (Generalitat de Catalunya; Grant 2009-SGR-1222 to A.J.). J.-M.T. received a JAE-Doc contract from the Spanish National Research Council (CSIC)-MICINN; R.M. a TA contract from CSIC-MICINN; and L.M.-A. an FPU predoctoral fellowship from MICINNPeer Reviewe
Molecular surveillance of pfhrp2 and pfhrp3 deletions in Plasmodium falciparum isolates from Mozambique
BACKGROUND: Malaria programmes use Plasmodium falciparum
histidine-rich protein-2 (PfHRP2) based rapid diagnostic tests
(RDTs) for malaria diagnosis. The deletion of this target
antigen could potentially lead to misdiagnosis, delayed
treatment and continuation of active transmission. METHODS:
Plasmodium falciparum isolates (n = 1162) collected in Southern
Mozambique were assessed by RDTs, microscopy and/or 18SrRNA
qPCR. pfhrp2 and pfhrp3 deletions were investigated in isolates
from individuals who were negative by RDT but positive by
microscopy and/or qPCR (n = 69) using gene-specific PCRs, with
kelch13 PCR as the parasite DNA control. RESULTS: Lack of pfhrp2
PCR amplification was observed in one of the 69 isolates
subjected to molecular analysis [1.45% (95% CI 0.3-7.8%)].
CONCLUSIONS: The low prevalence of pfhrp2 deletions suggests
that RDTs will detect the vast majority of the P. falciparum
infections. Nevertheless, active surveillance for changing
deletion frequencies is required
Dynamics of Afebrile Plasmodium falciparum Infections in Mozambican Men
Background: Afebrile Plasmodium falciparum infections usually
remain undetected and untreated in the community and could
potentially contribute to sustaining local malaria transmission
in areas aiming for malaria elimination. Methods: Thirty-two men
with afebrile P. falciparum infections detected with rapid
diagnostic test (RDTs) were followed for 28 days. Kaplan-Meier
estimates were computed to estimate probability of parasite
positivity and of reducing parasitaemia by half of its initial
level by day 28. Trends of parasite densities quantified by
microscopy and qPCR were assessed using Poisson regression
models, and the microscopy to qPCR positivity ratio was
calculated at each time point. Three survival distributions
(Gompertz, Weibull, and gamma) were used to evaluate their
strength of fit to the data and to predict the median lifetime
of infection. Results: The cumulative probability of parasite
qPCR positivity by day 28 was 81% (95% CI 60.2-91.6). Geometric
mean parasitemia at recruitment was 516.1 parasites/muL and fell
to <100 parasites/muL by day 3, reaching 56.7 parasites/muL
on day 28 (p-value<0.001). The ratio of P. falciparum
positive samples by microscopy to qPCR decreased from 0.9 to
0.52 from recruitment to day 28. The best model fit to the data
was obtained assuming a Gompertz distribution. Conclusions:
Afebrile P.falciparum infections detectable by RDT in
semi-immune adults fall and stabilize at low-density levels
during the first four days since detection, suggesting a rapid
decline of potential transmissibility in this hidden parasite
reservoir
In-Vivo Efficacy of Chloroquine to Clear Asymptomatic Infections in Mozambican Adults: A Randomized, Placebo-controlled Trial with Implications for Elimination Strategies
Recent reports regarding the re-emergence of parasite
sensitivity to chloroquine call for a new consideration of this
drug as an interesting complementary tool in malaria elimination
efforts, given its good safety profile and long half-life. A
randomized (2:1), single-blind, placebo-controlled trial was
conducted in Manhica, Mozambique, to assess the in-vivo efficacy
of chloroquine to clear plasmodium falciparum (Pf) asymptomatic
infections. Primary study endpoint was the rate of adequate and
parasitological response (ACPR) to therapy on day 28
(PCR-corrected). Day 0 isolates were analyzed to assess the
presence of the PfCRT-76T CQ resistance marker. A total of 52
and 27 male adults were included in the CQ and Placebo group
respectively. PCR-corrected ACPR was significantly higher in the
CQ arm 89.4% (95%CI 80-98%) compared to the placebo (p <
0.001). CQ cleared 49/50 infections within the first 72 h while
placebo cleared 12/26 (LRT p < 0.001). The PfCRT-76T mutation
was present only in one out of 108 (0.9%) samples at baseline,
well below the 84% prevalence found in 1999 in the same area.
This study presents preliminary evidence of a return of
chloroquine sensitivity in Mozambican Pf isolates, and calls for
its further evaluation in community-based malaria elimination
efforts, in combination with other effective anti-malarials.
TRIAL REGISTRATION: www.clinicalTrials.gov NCT02698748
Dynamics and dispensability of variant-specific histone H1 Lys-26/Ser-27 and Thr-165 post-translational modifications
Jean-Michel Terme et al.In mammals, the linker histone H1, involved in DNA packaging into chromatin, is represented by a family of variants. H1 tails undergo post-translational modifications (PTMs) that can be detected by mass spectrometry. We developed antibodies to analyze several of these as yet unexplored PTMs including the combination of H1.4 K26 acetylation or trimethylation and S27 phosphorylation. H1.2-T165 phosphorylation was detected at S and G2/M phases of the cell cycle and was dispensable for chromatin binding and cell proliferation; while the H1.4-K26 residue was essential for proper cell cycle progression. We conclude that histone H1 PTMs are dynamic over the cell cycle and that the recognition of modified lysines may be affected by phosphorylation of adjacent residues. © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.This work was supported by the Spanish Ministry of Science and Innovation (MICINN) and European Regional Development Fund (Grant BFU2011-23057 to A.J., and Grant BFU2008-00460 to P.S.), and by the Regional Government of Catalonia (Generalitat de Catalunya; Grant 2009-SGR-1222 to A.J.). J.-M.T. received a JAE-Doc contract from the Spanish National Research Council (CSIC)-MICINN; R.M. a TA contract from CSIC-MICINN; and L.M.-A. an FPU predoctoral fellowship from MICINNPeer Reviewe
Vocabulario de la enfermedad por el virus del ébola (EN-ES)
Se trata de un estudio terminológico sistemático sobre la enfermedad por el virus del Ébola (Ebola virus disease)
A multiphase program for malaria elimination in southern Mozambique (the Magude project): A before-after study
Background: Malaria eradication remains the long-term vision of the World Health Organization (WHO). However, whether malaria elimination is feasible in areas of stable transmission in sub-Saharan Africa with currently available tools remains a subject of debate. This study aimed to evaluate a multiphased malaria elimination project to interrupt Plasmodium falciparum malaria transmission in a rural district of southern Mozambique.
Methods and findings: A before-after study was conducted between 2015 and 2018 in the district of Magude, with 48,448 residents living in 10,965 households. Building on an enhanced surveillance system, two rounds of mass drug administrations (MDAs) per year over two years (phase I, August 2015-2017), followed by one year of reactive focal mass drug administrations (rfMDAs) (phase II, September 2017-June 2018) were deployed with annual indoor residual spraying (IRS), programmatically distributed long-lasting insecticidal nets (LLINs), and standard case management. The four MDA rounds covered 58%-72% of the population, and annual IRS reported coverage was >70%. Yearly parasite surveys and routine surveillance data were used to monitor the primary outcomes of the study-malaria prevalence and incidence-at baseline and annually since the onset of the project. Parasite prevalence by rapid diagnostic test (RDT) declined from 9.1% (95% confidence interval [CI] 7.0-11.8) in May 2015 to 2.6% (95% CI 2.0-3.4), representing a 71.3% (95% CI 71.1-71.4, p < 0.001) reduction after phase I, and to 1.4% (95% CI 0.9-2.2) after phase II. This represented an 84.7% (95% CI 81.4-87.4, p < 0.001) overall reduction in all-age prevalence. Case incidence fell from 195 to 75 cases per 1,000 during phase I (61.5% reduction) and to 67 per 1,000 during phase II (65.6% overall reduction). Interrupted time series (ITS) analysis was used to estimate the level and trend change in malaria cases associated with the set of project interventions and the number of cases averted. Phase I interventions were associated with a significant immediate reduction in cases of 69.1% (95% CI 57.5-77.6, p < 0.001). Phase II interventions were not associated with a level or trend change. An estimated 76.7% of expected cases were averted throughout the project (38,369 cases averted of 50,005 expected). One malaria-associated inpatient death was observed during the study period. There were 277 mild adverse events (AEs) recorded through the passive pharmacovigilance system during the four MDA rounds. One serious adverse event (SAE) that resulted in death was potentially related to the drug. The study was limited by the incomplete coverage of interventions, the quality of the routine and cross-sectional data collected, and the restricted accuracy of ITS analysis with a short pre-intervention period.
Conclusion: In this study, we observed that the interventions deployed during the Magude project fell short of interrupting P. falciparum transmission with the coverages achieved. While new tools and strategies may be required to eventually achieve malaria elimination in stable transmission areas of sub-Saharan Africa, this project showed that innovative mixes of interventions can achieve large reductions in disease burden, a necessary step in the pathway towards elimination
Setting the scene and generating evidence for malaria elimination in Southern Mozambique
Mozambique has historically been one of the countries
with the highest malaria burden in the world. Starting in the
1960s, malaria control efforts were intensified in the southern
region of the country, especially in Maputo city and Maputo
province, to aid regional initiatives aimed to eliminate malaria
in South Africa and eSwatini. Despite significant reductions in
malaria prevalence, elimination was never achieved. Following
the World Health Organization's renewed vision of a
malaria-free-world, and considering the achievements from the
past, the Mozambican National Malaria Control Programme (NMCP)
embarked on the development and implementation of a strategic
plan to accelerate from malaria control to malaria elimination
in southern Mozambique. An initial partnership, supported by the
Bill and Melinda Gates Foundation and the La Caixa Foundation,
led to the creation of the Mozambican Alliance Towards the
Elimination of Malaria (MALTEM) and the Malaria Technical and
Advisory Committee (MTAC) to promote national ownership and
partner coordination to work towards the goal of malaria
elimination in local and cross-border initiatives. Surveillance
systems to generate epidemiological and entomological
intelligence to inform the malaria control strategies were
strengthened, and an impact and feasibility assessment of
various interventions aimed to interrupt malaria transmission
were conducted in Magude district (Maputo Province) through the
"Magude Project". The primary aim of this project was to
generate evidence to inform malaria elimination strategies for
southern Mozambique. The goal of malaria elimination in areas of
low transmission intensity is now included in the national
malaria strategic plan for 2017-22 and the NMCP and its partners
have started to work towards this goal while evidence continues
to be generated to move the national elimination agenda forward
The Genomic and Immune Landscapes of Lethal Metastatic Breast Cancer
TCR repertoire; Breast cancer; Clade mutationsRepertori TCR; Cà ncer de mama; Mutacions cladeRepertorio TCR; Cáncer de mama; Mutaciones cladoThe detailed molecular characterization of lethal cancers is a prerequisite to understanding resistance to therapy and escape from cancer immunoediting. We performed extensive multi-platform profiling of multi-regional metastases in autopsies from 10 patients with therapy-resistant breast cancer. The integrated genomic and immune landscapes show that metastases propagate and evolve as communities of clones, reveal their predicted neo-antigen landscapes, and show that they can accumulate HLA loss of heterozygosity (LOH). The data further identify variable tumor microenvironments and reveal, through analyses of T cell receptor repertoires, that adaptive immune responses appear to co-evolve with the metastatic genomes. These findings reveal in fine detail the landscapes of lethal metastatic breast cancer
Cell free circulating tumor DNA in cerebrospinal fluid detects and monitors central nervous system involvement of B-cell lymphomas
The levels of cell free circulating tumor DNA (ctDNA) in plasma correlate with treatment response and outcome in systemic lymphomas. Notably, in brain tumors, the levels of ctDNA in the cerebrospinal fluid (CSF) are higher than in plasma. Nevertheless, their role in central nervous system (CNS) lymphomas remains elusive. We evaluated the CSF and plasma from 19 patients: 6 restricted CNS lymphomas, 1 systemic and CNS lymphoma, and 12 systemic lymphomas. We performed whole exome sequencing or targeted sequencing to identify somatic mutations of the primary tumor, then variant-specific droplet digital polymerase chain reaction was designed for each mutation. At time of enrollment, we found ctDNA in the CSF of all patients with restricted CNS lymphoma but not in patients with systemic lymphoma without CNS involvement. Conversely, plasma ctDNA was detected in only 2 out of 6 patients with restricted CNS lymphoma with lower variant allele frequencies than CSF ctDNA. Moreover, we detected CSF ctDNA in one patient with CNS lymphoma in complete remission and in one patient with systemic lymphoma, 3 and 8 months before CNS relapse was confirmed, indicating that CSF ctDNA might detect CNS relapse earlier than conventional methods. Finally, in two cases with CNS lymphoma, CSF ctDNA was still detected after treatment even though no tumoral cells were observed by flow cytometry (FC), indicating that CSF ctDNA detected residual disease better than FC. In conclusion, CSF ctDNA can detect CNS lesions better than plasma ctDNA and FC. In addition, CSF ctDNA predicted CNS relapse in CNS and systemic lymphomas
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