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1.  Panspecies Small-Molecule Disruptors of Heterochromatin-Mediated Transcriptional Gene Silencing 
Molecular and Cellular Biology  2014;35(4):662-674.
Heterochromatin underpins gene repression, genome integrity, and chromosome segregation. In the fission yeast Schizosaccharomyces pombe, conserved protein complexes effect heterochromatin formation via RNA interference-mediated recruitment of a histone H3 lysine 9 methyltransferase to cognate chromatin regions. To identify small molecules that inhibit heterochromatin formation, we performed an in vivo screen for loss of silencing of a dominant selectable kanMX reporter gene embedded within fission yeast centromeric heterochromatin. Two structurally unrelated compounds, HMS-I1 and HMS-I2, alleviated kanMX silencing and decreased repressive H3K9 methylation levels at the transgene. The decrease in methylation caused by HMS-I1 and HMS-I2 was observed at all loci regulated by histone methylation, including centromeric repeats, telomeric regions, and the mating-type locus, consistent with inhibition of the histone deacetylases (HDACs) Clr3 and/or Sir2. Chemical-genetic epistasis and expression profiles revealed that both compounds affect the activity of the Clr3-containing Snf2/HDAC repressor complex (SHREC). In vitro HDAC assays revealed that HMS-I1 and HMS-I2 inhibit Clr3 HDAC activity. HMS-I1 also alleviated transgene reporter silencing by heterochromatin in Arabidopsis and a mouse cell line, suggesting a conserved mechanism of action. HMS-I1 and HMS-I2 bear no resemblance to known inhibitors of chromatin-based activities and thus represent novel chemical probes for heterochromatin formation and function.
PMCID: PMC4301722  PMID: 25487573
2.  Artemisinin resistance – modelling the potential human and economic costs 
Malaria Journal  2014;13(1):452.
Artemisinin combination therapy is recommended as first-line treatment for falciparum malaria across the endemic world and is increasingly relied upon for treating vivax malaria where chloroquine is failing. Artemisinin resistance was first detected in western Cambodia in 2007, and is now confirmed in the Greater Mekong region, raising the spectre of a malaria resurgence that could undo a decade of progress in control, and threaten the feasibility of elimination. The magnitude of this threat has not been quantified.
This analysis compares the health and economic consequences of two future scenarios occurring once artemisinin-based treatments are available with high coverage. In the first scenario, artemisinin combination therapy (ACT) is largely effective in the management of uncomplicated malaria and severe malaria is treated with artesunate, while in the second scenario ACT are failing at a rate of 30%, and treatment of severe malaria reverts to quinine. The model is applied to all malaria-endemic countries using their specific estimates for malaria incidence, transmission intensity and GDP. The model describes the direct medical costs for repeated diagnosis and retreatment of clinical failures as well as admission costs for severe malaria. For productivity losses, the conservative friction costing method is used, which assumes a limited economic impact for individuals that are no longer economically active until they are replaced from the unemployment pool.
Using conservative assumptions and parameter estimates, the model projects an excess of 116,000 deaths annually in the scenario of widespread artemisinin resistance. The predicted medical costs for retreatment of clinical failures and for management of severe malaria exceed US$32 million per year. Productivity losses resulting from excess morbidity and mortality were estimated at US$385 million for each year during which failing ACT remained in use as first-line treatment.
These ‘ballpark’ figures for the magnitude of the health and economic threat posed by artemisinin resistance add weight to the call for urgent action to detect the emergence of resistance as early as possible and contain its spread from known locations in the Mekong region to elsewhere in the endemic world.
PMCID: PMC4254187  PMID: 25418416
Malaria; Artemisinins; Anti-malarial resistance; Economics
3.  Alterations to Bone Mineral Composition as an Early Indication of Osteomyelitis in the Diabetic Foot 
Diabetes Care  2013;36(11):3652-3654.
Osteomyelitis in the diabetic foot is a major risk factor for amputation, but there is a limited understanding of early-stage infection, impeding limb-preserving diagnoses. We hypothesized that bone composition measurements provide insight into the early pathophysiology of diabetic osteomyelitis.
Compositional analysis by Raman spectroscopy was performed on bone specimens from patients with a clinical diagnosis of osteomyelitis in the foot requiring surgical intervention as either a biopsy (n = 6) or an amputation (n = 11).
An unexpected result was the discovery of pathological calcium phosphate minerals in addition to normal bone mineral. Dicalcium phosphate dihydrate, also called brushite, and uncarbonated apatite were found to be exclusively associated with infected bone.
Compositional measurements provided a unique insight into the pathophysiology of osteomyelitis in diabetic foot ulcers. At-patient identification of pathological minerals by Raman spectroscopy may serve as an early-stage diagnostic approach.
PMCID: PMC3816922  PMID: 23920085
4.  Expression of Mesenchymal and α-Cell Phenotypic Markers in Islet β-Cells in Recently Diagnosed Diabetes 
Diabetes Care  2013;36(11):3818-3820.
Relative contributions of reversible β-cell dysfunction and true decrease in β-cell mass in type 2 diabetes remain unclear. Definitive rodent lineage-tracing studies have identified β-cell dedifferentiation and subsequent reprogramming to α-cell fate as a novel mechanism underlying β-cell failure. The aim was to determine whether phenotypes of β-cell dedifferentiation and plasticity are present in human diabetes.
Immunofluorescence colocalization studies using classical endocrine and mesenchymal phenotypic markers were undertaken using pancreatic sections and isolated islets from three individuals with diabetes and five nondiabetic control subjects.
Intraislet cytoplasmic coexpression of insulin and vimentin, insulin and glucagon, and vimentin and glucagon were demonstrated in all cases. These phenotypes were not present in nondiabetic control subjects.
Coexpression of mesenchymal and α-cell phenotypic markers in human diabetic islet β-cells has been confirmed, providing circumstantial evidence for β-cell dedifferentiation and possible reprogramming to α-cells in clinical diabetes.
PMCID: PMC3816907  PMID: 24062329
5.  The diminishing returns of atovaquone-proguanil for elimination of Plasmodium falciparum malaria: modelling mass drug administration and treatment 
Malaria Journal  2014;13(1):380.
Artemisinin resistance is a major threat to current efforts to eliminate Plasmodium falciparum malaria which rely heavily on the continuing efficacy of artemisinin combination therapy (ACT). It has been suggested that ACT should not be used in mass drug administration (MDA) in areas where artemisinin-resistant P. falciparum is prevalent, and that atovaquone-proguanil (A-P) might be a preferable alternative. However, a single point mutation in the cytochrome b gene confers high level resistance to atovaquone, and such mutant parasites arise frequently during treatment making A-P a vulnerable tool for elimination.
A deterministic, population level, mathematical model was developed based on data from Cambodia to explore the possible effects of large-scale use of A-P compared to dihydroartemisinin-piperaquine ACT for mass drug administration and/or treatment of P. falciparum malaria, with and without adjunctive primaquine (PQ) and long-lasting insecticide-treated bed nets (LLIN). The aim was local elimination.
The model showed the initial efficacy of ACT and A-P for MDA to be similar. However, each round of A-P MDA resulted in rapid acquisition and spread of atovaquone resistance. Even a single round of MDA could compromise efficacy sufficient to preclude its use for treatment or prophylaxis. A switch to A-P for treatment of symptomatic episodes resulted in a complete loss of efficacy in the population within four to five years of its introduction. The impact of MDA was temporary and a combination of maintained high coverage with ACT treatment for symptomatic individuals and LLIN was necessary for elimination.
For malaria elimination, A-P for MDA or treatment of symptomatic cases should be avoided. A combined strategy of high coverage with ACT for treatment of symptomatic episodes, LLIN and ACT + P MDA would be preferable.
Electronic supplementary material
The online version of this article (doi:10.1186/1475-2875-13-380) contains supplementary material, which is available to authorized users.
PMCID: PMC4192368  PMID: 25249272
Mathematical; Model; Falciparum; Malaria; Atovaquone; Artemisinin; Dihydroartemisinin; Resistance
6.  Assessment of Copy Number Status of Chromosomes 6 and 11 by FISH Provides Independent Prognostic Information in Primary Melanoma 
Melanoma incidence has been rising steadily for decades, while mortality rates have remained flat. This type of discordant pattern between incidence and mortality has been linked to diagnostic drift in cancers of the thyroid, breast, and prostate. Ancillary tests such as fluorescent in situ hybridization (FISH) are now being used to help differentiate melanomas from melanocytic nevi. Multicolor FISH has been shown to distinguish between these two with 86.7% sensitivity and 95.4% specificity. To assess the ability of FISH to differentiate melanomas with metastatic or lethal potential from those with an indolent disease course, we performed FISH with probes targeting 6p25, centromere 6, 6q23, and 11q13 on 144 primary melanomas with a minimal tumor thickness of 2 mm and compared the development of metastatic disease and melanoma-specific mortality as well as relapse-free and disease-specific survival between FISH-positive and negative cases. 82% of melanomas were positive by FISH according to previously defined criteria. The percentage was significantly higher (93%) in cases that developed systemic metastases (n=43) than in patients that did not (77%, n=101). FISH-positive primaries had a significantly increased risk of metastasis or melanoma-related death compared to FISH-negative cases (odds ratio 4.11, confidence interval (CI) 1.14-22.7 and 7.0, CI 1.03-300.4, respectively). FISH status remained an independent parameter when controlling for known prognostic factors. This data indicates that the group of melanomas diagnosed with routine histopathology that lack aberrations detected by FISH is enriched for melanomas with a more indolent disease course. This suggests that molecular techniques can assist in a more accurate identification of tumors with metastatic potential.
PMCID: PMC4153784  PMID: 21716079
7.  Ethics, Economics, and the Use of Primaquine to Reduce Falciparum Malaria Transmission in Asymptomatic Populations 
PLoS Medicine  2014;11(8):e1001704.
Yoel Lubell and colleagues consider ethical and economic perspectives on mass drug administration of primaquine to limit transmission of P. falciparum malaria.
Please see later in the article for the Editors' Summary
PMCID: PMC4137981  PMID: 25137246
8.  Digoxin Reduces 30-Day All-Cause Hospital Admission in Older Patients with Chronic Systolic Heart Failure 
The American journal of medicine  2013;126(8):701-708.
Heart failure is a leading cause of hospital admission and readmission in older adults. The new United States healthcare reform law has created provisions for financial penalties for hospitals with higher-than-expected 30-day all-cause readmission rates for hospitalized Medicare beneficiaries ≥65 years with heart failure. We examined the effect of digoxin on 30-day all-cause hospital admission in older patients with heart failure and reduced ejection fraction.
In the main Digitalis Investigation Group (DIG) trial, 6800 ambulatory patients with chronic heart failure (ejection fraction ≤45%) were randomly assigned to digoxin or placebo. Of these, 3405 were ≥65 years (mean age, 72 years, 25% women, 11% non-whites). The main outcome in the current analysis was 30-day all-cause hospital admission.
In the first 30 days after randomization, all-cause hospitalization occurred in 5.4% (92/1693) and 8.1% (139/1712) of patients in the digoxin and placebo groups, respectively, (hazard ratio {HR} when digoxin was compared with placebo, 0.66; 95% confidence interval {CI}, 0.51–0.86; p=0.002). Digoxin also reduced both 30-day cardiovascular (3.5% vs. 6.5%; HR, 0.53; 95% CI, 0.38–0.72; p<0.001) and heart failure (1.7 vs. 4.2%; HR, 0.40; 95% CI, 0.26–0.62; p<0.001) hospitalizations, with similar trends for 30-day all-cause mortality (0.7% vs. 1.3%; HR, 0.55; 95% CI, 0.27–1.11; p=0.096). Younger patients were at lower risk of events but obtained similar benefits from digoxin.
Digoxin reduces 30-day all-cause hospital admission in ambulatory older patients with chronic systolic heart failure. Future studies need to examine its effect on 30-day all-cause hospital readmission in hospitalized patients with acute heart failure.
PMCID: PMC3926199  PMID: 23490060
Digoxin; heart failure; 30-day all-cause hospital admission
9.  Evidence for a glassy state in strongly driven carbon 
Scientific Reports  2014;4:5214.
Here, we report results of an experiment creating a transient, highly correlated carbon state using a combination of optical and x-ray lasers. Scattered x-rays reveal a highly ordered state with an electrostatic energy significantly exceeding the thermal energy of the ions. Strong Coulomb forces are predicted to induce nucleation into a crystalline ion structure within a few picoseconds. However, we observe no evidence of such phase transition after several tens of picoseconds but strong indications for an over-correlated fluid state. The experiment suggests a much slower nucleation and points to an intermediate glassy state where the ions are frozen close to their original positions in the fluid.
PMCID: PMC4048912  PMID: 24909903
10.  Outcomes among non-ST-segment elevation acute coronary syndromes patients with no angiographically obstructive coronary artery disease: observations from 37,101 patients 
Limited data exist concerning outcomes of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) with no angiographically obstructive coronary artery disease (non-obstructive CAD). We assessed the frequency of clinical outcomes among patients with non-obstructive CAD compared with obstructive CAD.
Methods and results:
We pooled data from eight NSTE ACS randomized clinical trials from 1994 to 2008, including 37,101 patients who underwent coronary angiography. The primary outcome was 30-day death or myocardial infarction (MI). Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for 30-day death or MI for non-obstructive versus obstructive CAD were generated for each trial. Summary ORs (95% CIs) across trials were generated using random effects models. Overall, 3550 patients (9.6%) had non-obstructive CAD. They were younger, more were female, and fewer had diabetes mellitus, previous MI or prior percutaneous coronary intervention than patients with obstructive CAD. Thirty-day death or MI was less frequent among patients with non-obstructive CAD (2.2%) versus obstructive CAD (13.3%) (ORadj 0.15; 95% CI, 0.11–0.20); 30-day death or spontaneous MI and six-month mortality were also less frequent among patients with non-obstructive CAD (ORadj 0.19 (0.14–0.25) and 0.37 (0.28–0.49), respectively).
Among patients with NSTE ACS, one in 10 had non-obstructive CAD. Death or MI occurred in 2.2% of these patients by 30 days. Compared with patients with obstructive CAD, the rate of major cardiac events was lower in patients with non-obstructive CAD but was not negligible, prompting the need to better understand management strategies for this group.
PMCID: PMC3932771  PMID: 24562802
Acute coronary syndromes; angiography; atherosclerosis; coronary disease; infarction
11.  The Policy Implications of the Cost Structure of Home Health Agencies 
Medicare & Medicaid Research Review  2014;4(1):mmrr2014.004.01.a03.
To examine the cost structure of home health agencies by estimating an empirical cost function for those that are Medicare-certified, ten years following the implementation of prospective payment.
Design and Methods
2010 national Medicare cost report data for certified home health agencies were merged with case-mix information from the Outcome and Assessment Information Set (OASIS). We estimated a fully interacted (by tax status) hybrid cost function for 7,064 agencies and calculated marginal costs as percent of total costs for all variables.
The home health industry is dominated by for-profit agencies, which tend to be newer than the non-profit agencies and to have higher average costs per patient but lower costs per visit. For-profit agencies tend to have smaller scale operations and different cost structures, and are less likely to be affiliated with chains. Our estimates suggest diseconomies of scale, zero marginal cost for contracting with therapy workers, and a positive marginal cost for contracting with nurses, when controlling for quality.
Our findings suggest that efficiencies may be achieved by promoting non-profit, smaller agencies, with fewer contract nursing staff. This conclusion should be tested further in future studies that address some of the limitations of our study.
PMCID: PMC4062313  PMID: 24949224
home care; cost functions; economies of scale; marginal costs; case-mix
12.  Identification of new ALK and RET gene fusions from colorectal and lung cancer biopsies 
Nature medicine  2012;18(3):382-384.
Applying a next-generation sequencing assay targeting 145 cancer-relevant genes in 40 colorectal cancer and 24 non–small cell lung cancer formalin-fixed paraffin-embedded tissue specimens identified at least one clinically relevant genomic alteration in 59% of the samples and revealed two gene fusions, C2orf44-ALK in a colorectal cancer sample and KIF5B-RET in a lung adenocarcinoma. Further screening of 561 lung adenocarcinomas identified 11 additional tumors with KIF5B-RET gene fusions (2.0%; 95% CI 0.8–3.1%). Cells expressing oncogenic KIF5B-RET are sensitive to multi-kinase inhibitors that inhibit RET.
PMCID: PMC3916180  PMID: 22327622
13.  Joint Effects of Smoking and Sedentary Lifestyle on Lung Function in African Americans: The Jackson Heart Study Cohort 
This study examined: (a) differences in lung function between current and non current smokers who had sedentary lifestyles and non sedentary lifestyles and (b) the mediating effect of sedentary lifestyle on the association between smoking and lung function in African Americans. Sedentary lifestyle was defined as the lowest quartile of the total physical activity score. The results of linear and logistic regression analyses revealed that non smokers with non sedentary lifestyles had the highest level of lung function, and smokers with sedentary lifestyles had the lowest level. The female non-smokers with sedentary lifestyles had a significantly higher FEV1% predicted and FVC% predicted than smokers with non sedentary lifestyles (93.3% vs. 88.6%; p = 0.0102 and 92.1% vs. 86.9%; p = 0.0055 respectively). FEV1/FVC ratio for men was higher in non smokers with sedentary lifestyles than in smokers with non sedentary lifestyles (80.9 vs. 78.1; p = 0.0048). Though smoking is inversely associated with lung function, it seems to have a more deleterious effect than sedentary lifestyle on lung function. Physically active smokers had higher lung function than their non physically active counterparts.
PMCID: PMC3945550  PMID: 24477212
lung function; Jackson Heart Study; African Americans; smoking; sedentary lifestyle
14.  Assessing Risk Prediction Models Using Individual Participant Data From Multiple Studies 
Pennells, Lisa | Kaptoge, Stephen | White, Ian R. | Thompson, Simon G. | Wood, Angela M. | Tipping, Robert W. | Folsom, Aaron R. | Couper, David J. | Ballantyne, Christie M. | Coresh, Josef | Goya Wannamethee, S. | Morris, Richard W. | Kiechl, Stefan | Willeit, Johann | Willeit, Peter | Schett, Georg | Ebrahim, Shah | Lawlor, Debbie A. | Yarnell, John W. | Gallacher, John | Cushman, Mary | Psaty, Bruce M. | Tracy, Russ | Tybjærg-Hansen, Anne | Price, Jackie F. | Lee, Amanda J. | McLachlan, Stela | Khaw, Kay-Tee | Wareham, Nicholas J. | Brenner, Hermann | Schöttker, Ben | Müller, Heiko | Jansson, Jan-Håkan | Wennberg, Patrik | Salomaa, Veikko | Harald, Kennet | Jousilahti, Pekka | Vartiainen, Erkki | Woodward, Mark | D'Agostino, Ralph B. | Bladbjerg, Else-Marie | Jørgensen, Torben | Kiyohara, Yutaka | Arima, Hisatomi | Doi, Yasufumi | Ninomiya, Toshiharu | Dekker, Jacqueline M. | Nijpels, Giel | Stehouwer, Coen D. A. | Kauhanen, Jussi | Salonen, Jukka T. | Meade, Tom W. | Cooper, Jackie A. | Cushman, Mary | Folsom, Aaron R. | Psaty, Bruce M. | Shea, Steven | Döring, Angela | Kuller, Lewis H. | Grandits, Greg | Gillum, Richard F. | Mussolino, Michael | Rimm, Eric B. | Hankinson, Sue E. | Manson, JoAnn E. | Pai, Jennifer K. | Kirkland, Susan | Shaffer, Jonathan A. | Shimbo, Daichi | Bakker, Stephan J. L. | Gansevoort, Ron T. | Hillege, Hans L. | Amouyel, Philippe | Arveiler, Dominique | Evans, Alun | Ferrières, Jean | Sattar, Naveed | Westendorp, Rudi G. | Buckley, Brendan M. | Cantin, Bernard | Lamarche, Benoît | Barrett-Connor, Elizabeth | Wingard, Deborah L. | Bettencourt, Richele | Gudnason, Vilmundur | Aspelund, Thor | Sigurdsson, Gunnar | Thorsson, Bolli | Kavousi, Maryam | Witteman, Jacqueline C. | Hofman, Albert | Franco, Oscar H. | Howard, Barbara V. | Zhang, Ying | Best, Lyle | Umans, Jason G. | Onat, Altan | Sundström, Johan | Michael Gaziano, J. | Stampfer, Meir | Ridker, Paul M. | Michael Gaziano, J. | Ridker, Paul M. | Marmot, Michael | Clarke, Robert | Collins, Rory | Fletcher, Astrid | Brunner, Eric | Shipley, Martin | Kivimäki, Mika | Ridker, Paul M. | Buring, Julie | Cook, Nancy | Ford, Ian | Shepherd, James | Cobbe, Stuart M. | Robertson, Michele | Walker, Matthew | Watson, Sarah | Alexander, Myriam | Butterworth, Adam S. | Angelantonio, Emanuele Di | Gao, Pei | Haycock, Philip | Kaptoge, Stephen | Pennells, Lisa | Thompson, Simon G. | Walker, Matthew | Watson, Sarah | White, Ian R. | Wood, Angela M. | Wormser, David | Danesh, John
American Journal of Epidemiology  2013;179(5):621-632.
Individual participant time-to-event data from multiple prospective epidemiologic studies enable detailed investigation into the predictive ability of risk models. Here we address the challenges in appropriately combining such information across studies. Methods are exemplified by analyses of log C-reactive protein and conventional risk factors for coronary heart disease in the Emerging Risk Factors Collaboration, a collation of individual data from multiple prospective studies with an average follow-up duration of 9.8 years (dates varied). We derive risk prediction models using Cox proportional hazards regression analysis stratified by study and obtain estimates of risk discrimination, Harrell's concordance index, and Royston's discrimination measure within each study; we then combine the estimates across studies using a weighted meta-analysis. Various weighting approaches are compared and lead us to recommend using the number of events in each study. We also discuss the calculation of measures of reclassification for multiple studies. We further show that comparison of differences in predictive ability across subgroups should be based only on within-study information and that combining measures of risk discrimination from case-control studies and prospective studies is problematic. The concordance index and discrimination measure gave qualitatively similar results throughout. While the concordance index was very heterogeneous between studies, principally because of differing age ranges, the increments in the concordance index from adding log C-reactive protein to conventional risk factors were more homogeneous.
PMCID: PMC3927974  PMID: 24366051
C index; coronary heart disease; D measure; individual participant data; inverse variance; meta-analysis; risk prediction; weighting
15.  Sequencing of Culex quinquefasciatus establishes a platform for mosquito comparative genomics 
Arensburger, Peter | Megy, Karine | Waterhouse, Robert M. | Abrudan, Jenica | Amedeo, Paolo | Antelo, Beatriz | Bartholomay, Lyric | Bidwell, Shelby | Caler, Elisabet | Camara, Francisco | Campbell, Corey L. | Campbell, Kathryn S. | Casola, Claudio | Castro, Marta T. | Chandramouliswaran, Ishwar | Chapman, Sinéad B. | Christley, Scott | Costas, Javier | Eisenstadt, Eric | Feshotte, Cedric | Fraser-Liggett, Claire | Guigo, Roderic | Haas, Brian | Hammond, Martin | Hansson, Bill S. | Hemingway, Janet | Hill, Sharon | Howarth, Clint | Ignell, Rickard | Kennedy, Ryan C. | Kodira, Chinnappa D. | Lobo, Neil F. | Mao, Chunhong | Mayhew, George | Michel, Kristin | Mori, Akio | Liu, Nannan | Naveira, Horacio | Nene, Vishvanath | Nguyen, Nam | Pearson, Matthew D. | Pritham, Ellen J. | Puiu, Daniela | Qi, Yumin | Ranson, Hilary | Ribeiro, Jose M. C. | Roberston, Hugh M. | Severson, David W. | Shumway, Martin | Stanke, Mario | Strausberg, Robert | Sun, Cheng | Sutton, Granger | Tu, Zhijian (Jake) | Tubio, Jose Manuel C. | Unger, Maria F. | Vanlandingham, Dana L. | Vilella, Albert J. | White, Owen | White, Jared R. | Wondji, Charles S. | Wortman, Jennifer | Zdobnov, Evgeny M. | Birren, Bruce | Christensen, Bruce M. | Collins, Frank H. | Cornel, Anthony | Dimopoulos, George | Hannick, Linda I. | Higgs, Stephen | Lanzaro, Gregory C. | Lawson, Daniel | Lee, Norman H. | Muskavitch, Marc A. T. | Raikhel, Alexander S. | Atkinson, Peter W.
Science (New York, N.Y.)  2010;330(6000):86-88.
Culex quinquefasciatus (the Southern house mosquito) is an important mosquito vector of viruses such as West Nile virus and St. Louis encephalitis virus as well of nematodes that cause lymphatic filariasis. It is one species within the Culex pipiens species complex and enjoys a distribution throughout tropical and temperate climates of the world. The ability of C. quinquefasciatus to take blood meals from birds, livestock and humans contributes to its ability to vector pathogens between species. We describe the genomic sequence of C. quinquefasciatus, its repertoire of 18,883 protein-coding genes is 22% larger than Ae. aegypti and 52% larger than An. gambiae with multiple gene family expansions including olfactory and gustatory receptors, salivary gland genes, and genes associated with xenobiotic detoxification.
PMCID: PMC3740384  PMID: 20929810
16.  Cactin is essential for G1 progression in Toxoplasma gondii 
Molecular Microbiology  2012;84(3):566-577.
Toxoplasma gondii is an obligate intracellular protozoan parasite whose rapid lytic replication cycles define its pathogenicity. We identified a temperature sensitive growth mutant, FV-P6, which irreversibly arrests before the middle of the G1 stage of the tachyzoite cell cycle. This arrest is caused by a point mutation in a gene conserved across eukaryotes, Cactin, whose product localizes to the nucleus. To elucidate the role of TgCactin we performed genome-wide expression profiling. Besides the expected G1 expression profile, many genes associated with the extracellular state as well as with the bradyzoite cyst stage were identified. Consistent with these profiles were the expression of AP2 transcription factors typically associated with extracellular and bradyzoite stage parasites. This suggests a role for TgCactin in control of gene expression. Since TgCactin does not contain any functionally defined domains we reasoned TgCactin exerts its function through interactions with other proteins. In support of this model we demonstrated that TgCactin is present in a protein complex and can oligomerize. Taken together, these results suggest that TgCactin acts as a pivotal protein potentially regulating gene expression at several transition points in parasite development.
PMCID: PMC3331927  PMID: 22486860
Toxoplasma; Cactin; cell cycle; G1; AP2
17.  CloVR-ITS: Automated internal transcribed spacer amplicon sequence analysis pipeline for the characterization of fungal microbiota 
Microbiome  2013;1:6.
Besides the development of comprehensive tools for high-throughput 16S ribosomal RNA amplicon sequence analysis, there exists a growing need for protocols emphasizing alternative phylogenetic markers such as those representing eukaryotic organisms.
Here we introduce CloVR-ITS, an automated pipeline for comparative analysis of internal transcribed spacer (ITS) pyrosequences amplified from metagenomic DNA isolates and representing fungal species. This pipeline performs a variety of steps similar to those commonly used for 16S rRNA amplicon sequence analysis, including preprocessing for quality, chimera detection, clustering of sequences into operational taxonomic units (OTUs), taxonomic assignment (at class, order, family, genus, and species levels) and statistical analysis of sample groups of interest based on user-provided information. Using ITS amplicon pyrosequencing data from a previous human gastric fluid study, we demonstrate the utility of CloVR-ITS for fungal microbiota analysis and provide runtime and cost examples, including analysis of extremely large datasets on the cloud. We show that the largest fractions of reads from the stomach fluid samples were assigned to Dothideomycetes, Saccharomycetes, Agaricomycetes and Sordariomycetes but that all samples were dominated by sequences that could not be taxonomically classified. Representatives of the Candida genus were identified in all samples, most notably C. quercitrusa, while sequence reads assigned to the Aspergillus genus were only identified in a subset of samples. CloVR-ITS is made available as a pre-installed, automated, and portable software pipeline for cloud-friendly execution as part of the CloVR virtual machine package (
The CloVR-ITS pipeline provides fungal microbiota analysis that can be complementary to bacterial 16S rRNA and total metagenome sequence analysis allowing for more comprehensive studies of environmental and host-associated microbial communities.
PMCID: PMC3869194  PMID: 24451270
Internal transcribed spacer (ITS); Fungal microbiota; Automated sequence analysis pipeline; Cloud computing
18.  Survivin Expression Induced by Endothelin-1 Promotes Myofibroblast Resistance to Apoptosis 
Fibrosis of the lungs and other organs is characterized by the accumulation of myofibroblasts, effectors of wound-repair that are responsible for the deposition and organization of new extracellular matrix (ECM) in response to tissue injury. During the resolution phase of normal wound repair, myofibroblast apoptosis limits the continued deposition of ECM. Mounting evidence suggests that myofibroblasts from fibrotic wounds acquire resistance to apoptosis, but the mechanisms regulating this resistance have not been fully elucidated. Endothelin-1 (ET-1), a soluble peptide strongly associated with fibrogenesis, decreases myofibroblast susceptibility to apoptosis through activation of phosphatidylinositol 3′-OH kinase (PI3K)/AKT. Focal adhesion kinase (FAK) also promotes myofibroblast resistance to apoptosis through PI3K/AKT-dependent and – independent mechanisms, although the role of FAK in ET-1 mediated resistance to apoptosis has not been explored. The goal of this study was to investigate whether FAK contributes to ET-1 mediated myofibroblast resistance to apoptosis and to examine potential mechanisms downstream of FAK and PI3K/AKT by which ET-1 regulates myofibroblast survival. Here, we show that ET-1 regulates myofibroblast survival by Rho/ROCK-dependent activation of FAK. The anti-apoptotic actions of FAK are, in turn, dependent on activation of PI3K/AKT and the subsequent increased expression of Survivin, a member of the inhibitor of apoptosis protein (IAP) family. Collectively, these studies define a novel mechanism by which ET-1 promotes myofibroblast resistance to apoptosis through upregulation of Survivin.
PMCID: PMC3241828  PMID: 22041029
Fibrosis; Rho-kinase; Inhibitor of Apoptosis; Mesenchymal Cell; Focal Adhesion Kinase; AKT
19.  A framework for human microbiome research 
Methé, Barbara A. | Nelson, Karen E. | Pop, Mihai | Creasy, Heather H. | Giglio, Michelle G. | Huttenhower, Curtis | Gevers, Dirk | Petrosino, Joseph F. | Abubucker, Sahar | Badger, Jonathan H. | Chinwalla, Asif T. | Earl, Ashlee M. | FitzGerald, Michael G. | Fulton, Robert S. | Hallsworth-Pepin, Kymberlie | Lobos, Elizabeth A. | Madupu, Ramana | Magrini, Vincent | Martin, John C. | Mitreva, Makedonka | Muzny, Donna M. | Sodergren, Erica J. | Versalovic, James | Wollam, Aye M. | Worley, Kim C. | Wortman, Jennifer R. | Young, Sarah K. | Zeng, Qiandong | Aagaard, Kjersti M. | Abolude, Olukemi O. | Allen-Vercoe, Emma | Alm, Eric J. | Alvarado, Lucia | Andersen, Gary L. | Anderson, Scott | Appelbaum, Elizabeth | Arachchi, Harindra M. | Armitage, Gary | Arze, Cesar A. | Ayvaz, Tulin | Baker, Carl C. | Begg, Lisa | Belachew, Tsegahiwot | Bhonagiri, Veena | Bihan, Monika | Blaser, Martin J. | Bloom, Toby | Vivien Bonazzi, J. | Brooks, Paul | Buck, Gregory A. | Buhay, Christian J. | Busam, Dana A. | Campbell, Joseph L. | Canon, Shane R. | Cantarel, Brandi L. | Chain, Patrick S. | Chen, I-Min A. | Chen, Lei | Chhibba, Shaila | Chu, Ken | Ciulla, Dawn M. | Clemente, Jose C. | Clifton, Sandra W. | Conlan, Sean | Crabtree, Jonathan | Cutting, Mary A. | Davidovics, Noam J. | Davis, Catherine C. | DeSantis, Todd Z. | Deal, Carolyn | Delehaunty, Kimberley D. | Dewhirst, Floyd E. | Deych, Elena | Ding, Yan | Dooling, David J. | Dugan, Shannon P. | Dunne, Wm. Michael | Durkin, A. Scott | Edgar, Robert C. | Erlich, Rachel L. | Farmer, Candace N. | Farrell, Ruth M. | Faust, Karoline | Feldgarden, Michael | Felix, Victor M. | Fisher, Sheila | Fodor, Anthony A. | Forney, Larry | Foster, Leslie | Di Francesco, Valentina | Friedman, Jonathan | Friedrich, Dennis C. | Fronick, Catrina C. | Fulton, Lucinda L. | Gao, Hongyu | Garcia, Nathalia | Giannoukos, Georgia | Giblin, Christina | Giovanni, Maria Y. | Goldberg, Jonathan M. | Goll, Johannes | Gonzalez, Antonio | Griggs, Allison | Gujja, Sharvari | Haas, Brian J. | Hamilton, Holli A. | Harris, Emily L. | Hepburn, Theresa A. | Herter, Brandi | Hoffmann, Diane E. | Holder, Michael E. | Howarth, Clinton | Huang, Katherine H. | Huse, Susan M. | Izard, Jacques | Jansson, Janet K. | Jiang, Huaiyang | Jordan, Catherine | Joshi, Vandita | Katancik, James A. | Keitel, Wendy A. | Kelley, Scott T. | Kells, Cristyn | Kinder-Haake, Susan | King, Nicholas B. | Knight, Rob | Knights, Dan | Kong, Heidi H. | Koren, Omry | Koren, Sergey | Kota, Karthik C. | Kovar, Christie L. | Kyrpides, Nikos C. | La Rosa, Patricio S. | Lee, Sandra L. | Lemon, Katherine P. | Lennon, Niall | Lewis, Cecil M. | Lewis, Lora | Ley, Ruth E. | Li, Kelvin | Liolios, Konstantinos | Liu, Bo | Liu, Yue | Lo, Chien-Chi | Lozupone, Catherine A. | Lunsford, R. Dwayne | Madden, Tessa | Mahurkar, Anup A. | Mannon, Peter J. | Mardis, Elaine R. | Markowitz, Victor M. | Mavrommatis, Konstantinos | McCorrison, Jamison M. | McDonald, Daniel | McEwen, Jean | McGuire, Amy L. | McInnes, Pamela | Mehta, Teena | Mihindukulasuriya, Kathie A. | Miller, Jason R. | Minx, Patrick J. | Newsham, Irene | Nusbaum, Chad | O’Laughlin, Michelle | Orvis, Joshua | Pagani, Ioanna | Palaniappan, Krishna | Patel, Shital M. | Pearson, Matthew | Peterson, Jane | Podar, Mircea | Pohl, Craig | Pollard, Katherine S. | Priest, Margaret E. | Proctor, Lita M. | Qin, Xiang | Raes, Jeroen | Ravel, Jacques | Reid, Jeffrey G. | Rho, Mina | Rhodes, Rosamond | Riehle, Kevin P. | Rivera, Maria C. | Rodriguez-Mueller, Beltran | Rogers, Yu-Hui | Ross, Matthew C. | Russ, Carsten | Sanka, Ravi K. | Pamela Sankar, J. | Sathirapongsasuti, Fah | Schloss, Jeffery A. | Schloss, Patrick D. | Schmidt, Thomas M. | Scholz, Matthew | Schriml, Lynn | Schubert, Alyxandria M. | Segata, Nicola | Segre, Julia A. | Shannon, William D. | Sharp, Richard R. | Sharpton, Thomas J. | Shenoy, Narmada | Sheth, Nihar U. | Simone, Gina A. | Singh, Indresh | Smillie, Chris S. | Sobel, Jack D. | Sommer, Daniel D. | Spicer, Paul | Sutton, Granger G. | Sykes, Sean M. | Tabbaa, Diana G. | Thiagarajan, Mathangi | Tomlinson, Chad M. | Torralba, Manolito | Treangen, Todd J. | Truty, Rebecca M. | Vishnivetskaya, Tatiana A. | Walker, Jason | Wang, Lu | Wang, Zhengyuan | Ward, Doyle V. | Warren, Wesley | Watson, Mark A. | Wellington, Christopher | Wetterstrand, Kris A. | White, James R. | Wilczek-Boney, Katarzyna | Wu, Yuan Qing | Wylie, Kristine M. | Wylie, Todd | Yandava, Chandri | Ye, Liang | Ye, Yuzhen | Yooseph, Shibu | Youmans, Bonnie P. | Zhang, Lan | Zhou, Yanjiao | Zhu, Yiming | Zoloth, Laurie | Zucker, Jeremy D. | Birren, Bruce W. | Gibbs, Richard A. | Highlander, Sarah K. | Weinstock, George M. | Wilson, Richard K. | White, Owen
Nature  2012;486(7402):215-221.
A variety of microbial communities and their genes (microbiome) exist throughout the human body, playing fundamental roles in human health and disease. The NIH funded Human Microbiome Project (HMP) Consortium has established a population-scale framework which catalyzed significant development of metagenomic protocols resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 to 18 body sites up to three times, which to date, have generated 5,177 microbial taxonomic profiles from 16S rRNA genes and over 3.5 Tb of metagenomic sequence. In parallel, approximately 800 human-associated reference genomes have been sequenced. Collectively, these data represent the largest resource to date describing the abundance and variety of the human microbiome, while providing a platform for current and future studies.
PMCID: PMC3377744  PMID: 22699610
20.  Biomedical Tissue Phantoms with Controlled Geometric and Optical Properties for Raman Spectroscopy and Tomography 
The Analyst  2011;136(21):4437-4446.
To support the translation of Raman spectroscopy into clinical applications, synthetic models are needed to accurately test, optimize and validate prototype fiber optic instrumentation. Synthetic models (also called tissue phantoms) are widely used for developing and testing optical instrumentation for diffuse reflectance, fluorescence, and Raman spectroscopies. While existing tissue phantoms accurately model tissue optical scattering and absorption, they do not typically model the anatomic shapes and chemical composition of tissue. Because Raman spectroscopy is sensitive to molecular composition, Raman tissue phantoms should also approximate the bulk tissue composition. We describe the fabrication and characterization of tissue phantoms for Raman tomography and spectroscopy. These phantoms have controlled chemical and optical properties, and also multilayer morphologies which approximate the appropriate anatomic shapes. Tissue phantoms were fabricated to support on-going Raman studies by simulating human wrist and rat leg. Surface meshes (triangle patch models) were generated from computed tomography (CT) images of a human arm and rat leg. Rapid prototyping was used to print mold templates with complex geometric patterns. Plastic casting techniques used for movie special effects were adapted to fabricate molds from the rapid prototypes, and finally to cast multilayer gelatin tissue phantoms. The gelatin base was enriched with additives to model the approximate chemistry and optical properties of individual tissue layers. Additional studies were performed to determine optimal casting conditions, phantom stability, layer delamination and chemical diffusion between layers. Recovery of diffuse reflectance and Raman spectra in tissue phantoms varied with probe placement. These phantoms enable optimization of probe placement for human or rat studies. These multilayer tissue phantoms with complex geometries are shown to be stable, with minimal layer delamination and chemical diffusion.
PMCID: PMC3289090  PMID: 21912794
21.  Defining Falciparum-Malaria-Attributable Severe Febrile Illness in Moderate-to-High Transmission Settings on the Basis of Plasma PfHRP2 Concentration 
The Journal of Infectious Diseases  2012;207(2):351-361.
Background. In malaria-endemic settings, asymptomatic parasitemia complicates the diagnosis of malaria. Histidine-rich protein 2 (HRP2) is produced by Plasmodium falciparum, and its plasma concentration reflects the total body parasite burden. We aimed to define the malaria-attributable fraction of severe febrile illness, using the distributions of plasma P. falciparum HRP2 (PfHRP2) concentrations from parasitemic children with different clinical presentations.
Methods. Plasma samples were collected from and peripheral blood slides prepared for 1435 children aged 6−60 months in communities and a nearby hospital in northeastern Tanzania. The study population included children with severe or uncomplicated malaria, asymptomatic carriers, and healthy control subjects who had negative results of rapid diagnostic tests. The distributions of plasma PfHRP2 concentrations among the different groups were used to model severe malaria-attributable disease.
Results. The plasma PfHRP2 concentration showed a close correlation with the severity of infection. PfHRP2 concentrations of >1000 ng/mL denoted a malaria-attributable fraction of severe disease of 99% (95% credible interval [CI], 96%–100%), with a sensitivity of 74% (95% CI, 72%–77%), whereas a concentration of <200 ng/mL denoted severe febrile illness of an alternative diagnosis in >10% (95% CI, 3%–27%) of patients. Bacteremia was more common among patients in the lowest and highest PfHRP2 concentration quintiles.
Conclusions. The plasma PfHRP2 concentration defines malaria-attributable disease and distinguishes severe malaria from coincidental parasitemia in African children in a moderate-to-high transmission setting.
PMCID: PMC3532834  PMID: 23136222
case definition; severe malaria; Plasmodium falciparum; histidine-rich protein 2; malaria-attributable disease; asymptomatic parasitemia; bacteremia; Tanzania
22.  Temporal trends in severe malaria in Chittagong, Bangladesh 
Malaria Journal  2012;11:323.
Epidemiological data on malaria in Bangladesh are sparse, particularly on severe and fatal malaria. This hampers the allocation of healthcare provision in this resource-poor setting. Over 85% of the estimated 150,000-250,000 annual malaria cases in Bangladesh occur in Chittagong Division with 80% in the Chittagong Hill Tracts (CHT). Chittagong Medical College Hospital (CMCH) is the major tertiary referral hospital for severe malaria in Chittagong Division.
Malaria screening data from 22,785 inpatients in CMCH from 1999–2011 were analysed to investigate the patterns of referral, temporal trends and geographical distribution of severe malaria in Chittagong Division, Bangladesh.
From 1999 till 2011, 2,394 malaria cases were admitted, of which 96% harboured Plasmodium falciparum and 4% Plasmodium vivax. Infection was commonest in males (67%) between 15 and 34 years of age. Seasonality of malaria incidence was marked with a single peak in P. falciparum transmission from June to August coinciding with peak rainfall, whereas P. vivax showed an additional peak in February-March possibly representing relapse infections. Since 2007 there has been a substantial decrease in the absolute number of admitted malaria cases. Case fatality in severe malaria was 18% from 2008–2011, remaining steady during this period.
A travel history obtained in 226 malaria patients revealed only 33% had been to the CHT in the preceding three weeks. Of all admitted malaria patients, only 9% lived in the CHT, and none in the more remote malaria endemic regions near the Indian border.
The overall decline in admitted malaria cases to CMCH suggests recent control measures are successful. However, there are no reliable data on the incidence of severe malaria in the CHT, the most endemic area of Bangladesh, and most of these patients do not reach tertiary health facilities. Improvement of early treatment and simple supportive care for severe malaria in remote areas and implementation of a referral system for cases requiring additional supportive care could be important contributors to further reducing malaria-attributable disease and death in Bangladesh.
PMCID: PMC3544696  PMID: 22970881
Malaria; Bangladesh; Epidemiology; Incidence; Severe; Falciparum; Vivax
23.  Diagnosing Severe Falciparum Malaria in Parasitaemic African Children: A Prospective Evaluation of Plasma PfHRP2 Measurement 
PLoS Medicine  2012;9(8):e1001297.
Arjen Dondorp and colleagues investigate whether the plasma level of Plasmodium falciparum histidine-rich protein 2 can be used to distinguish between severe malaria and other severe febrile illness in African children with malaria.
In African children, distinguishing severe falciparum malaria from other severe febrile illnesses with coincidental Plasmodium falciparum parasitaemia is a major challenge. P. falciparum histidine-rich protein 2 (PfHRP2) is released by mature sequestered parasites and can be used to estimate the total parasite burden. We investigated the prognostic significance of plasma PfHRP2 and used it to estimate the malaria-attributable fraction in African children diagnosed with severe malaria.
Methods and Findings
Admission plasma PfHRP2 was measured prospectively in African children (from Mozambique, The Gambia, Kenya, Tanzania, Uganda, Rwanda, and the Democratic Republic of the Congo) aged 1 month to 15 years with severe febrile illness and a positive P. falciparum lactate dehydrogenase (pLDH)-based rapid test in a clinical trial comparing parenteral artesunate versus quinine (the AQUAMAT trial, ISRCTN 50258054). In 3,826 severely ill children, Plasmadium falciparum PfHRP2 was higher in patients with coma (p = 0.0209), acidosis (p<0.0001), and severe anaemia (p<0.0001). Admission geometric mean (95%CI) plasma PfHRP2 was 1,611 (1,350–1,922) ng/mL in fatal cases (n = 381) versus 1,046 (991–1,104) ng/mL in survivors (n = 3,445, p<0.0001), without differences in parasitaemia as assessed by microscopy. There was a U-shaped association between log10 plasma PfHRP2 and risk of death. Mortality increased 20% per log10 increase in PfHRP2 above 174 ng/mL (adjusted odds ratio [AOR] 1.21, 95%CI 1.05–1.39, p = 0.009). A mechanistic model assuming a PfHRP2-independent risk of death in non-malaria illness closely fitted the observed data and showed malaria-attributable mortality less than 50% with plasma PfHRP2≤174 ng/mL. The odds ratio (OR) for death in artesunate versus quinine-treated patients was 0.61 (95%CI 0.44–0.83, p = 0.0018) in the highest PfHRP2 tertile, whereas there was no difference in the lowest tertile (OR 1.05; 95%CI 0.69–1.61; p = 0.82). A limitation of the study is that some conclusions are drawn from a mechanistic model, which is inherently dependent on certain assumptions. However, a sensitivity analysis of the model indicated that the results were robust to a plausible range of parameter estimates. Further studies are needed to validate our findings.
Plasma PfHRP2 has prognostic significance in African children with severe falciparum malaria and provides a tool to stratify the risk of “true” severe malaria-attributable disease as opposed to other severe illnesses in parasitaemic African children.
Please see later in the article for the Editors' Summary.
Editors' Summary
Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected mosquitoes. In 2010, malaria caused an estimated 655,000 deaths worldwide, mostly in Africa, where according to the World Health Organization, one African child dies every minute from the disease. There are four Plasmodium parasite species that cause malaria in humans, with one species, Plasmodium falciparum, causing the most severe disease. However, diagnosing severe falciparum malaria in children living in endemic areas is problematic, as many semi-immune children may have the malaria parasites in their blood (described as being parasitaemic) but do not have clinical disease. Therefore, a positive malaria blood smear may be coincidental and not be diagnostic of severe malaria, and unfortunately, neither are the clinical symptoms of severe malaria, such as shock, acidosis, or coma, which can also be caused by other childhood infections. For these reasons, the misdiagnosis of falciparum malaria in severely ill children is an important problem in sub-Saharan Africa, and may result in unnecessary child deaths.
Why Was This Study Done?
Previous studies have suggested that a parasite protein—P. falciparum histidine-rich protein-2 (PfHRP2)—is a measure of the total number of parasites in the patient. Unlike the circulating parasites detected on a blood film, which do not represent the parasites that get stuck in vital organs, PfHRP2 is distributed equally through the total blood plasma volume, and so can be considered a measure of the total parasite burden in the previous 48 hours. So in this study, the researchers assessed the prognostic value of plasma PfHRP2 in African children with severe malaria and whether this protein could distinguish children who really do have severe malaria from those who have severe febrile illness but coincidental parasitaemia, who may have another infection.
What Did the Researchers Do and Find?
The researchers assessed levels of plasma PfHRP2 in 3,826 out of a possible 5,425 African children who participated in a large multinational trial (in Mozambique, The Gambia, Rwanda, Tanzania, Kenya, Uganda, and the Democratic Republic of Congo) that compared the anti-malarial drugs quinine and artesunate for the treatment of severe malaria. All children had a clinical diagnosis of severe malaria confirmed by a rapid diagnostic test, and the researchers used clinical signs to define the severity of malaria. The researchers assessed the relationship between plasma PfHRP2 concentrations and risk of death taking other well established predictors of death, such as coma, convulsions, hypoglycaemia, respiratory distress, and shock, into account.
The researchers found that PfHRP2 was detectable in 3,800/3,826 (99%) children with severe malaria and that the average plasma PfHRP2 levels was significantly higher in the 381 children who died from malaria than in children who survived (1,611 ng/mL versus 1,046 ng/mL). Plasma PfHRP2 was also significantly higher in children with severe malaria signs and symptoms such as coma, acidosis, and severe anaemia. Importantly, the researchers found that high death rates were associated with either very low or very high values of plasma PfHRP2: the odds (chance) of death were 20% higher per unit increase in PfHRP2 above a specific threshold (174 ng/ml), but below this concentration, the risk of death increased with decreasing levels, probably because at lower levels disease was caused by a severe febrile disease other than malaria, like septicemia. Finally, the researchers found that in children within the highest PfHRP2 tertile, the chance of death when treated with the antimalarial drug artesunate versus quinine was 0.61 but that there was no difference in death rates in the lowest tertile, which supports that patients with very low plasma PfHRP2 have a different severe febrile illness than malaria. The researchers use mathematical modeling to provide cut-off values for plasma PfHRP2 denoting the proportion of patients with a diagnosis other than severe malaria.
What Do These Findings Mean?
These findings suggest that in areas of moderate or high malaria transmission where a high proportion of children are parasitaemic, plasma PfHRP2 levels taken on admission to hospital can differentiate children at highest risk of death from severe falciparum malaria from those likely to have alternative causes of severe febrile illness. Therefore, plasma PfHRP2 could be considered a valuable additional diagnostic tool and prognostic indicator in African children with severe falciparum malaria. This finding is important for clinicians treating children with severe febrile illnesses in malaria-endemic countries: while high levels of plasma PfHRP2 is indicative of severe malaria which needs urgent antimalarial treatment, low levels suggest that another severe infective disease should be considered, warranting additional investigations and urgent treatment with antibiotics.
Additional Information
Please access these Web sites via the online version of this summary at
A previous small study in PLOS ONE explores the relationship between plasma PfHRP2 and severe malaria in Tanzanian children
The WHO website and the website of Malaria No More have comprehensive information about malaria
PMCID: PMC3424256  PMID: 22927801
24.  Structure-guided lead optimization of triazolopyrimidine-ring substituents identifies potent Plasmodium falciparum dihydroorotate dehydrogenase inhibitors with clinical candidate potential 
Journal of medicinal chemistry  2011;54(15):5540-5561.
Drug therapy is the mainstay of antimalarial therapy, yet current drugs are threatened by the development of resistance. In an effort to identify new potential anti-malarials we have undertaken a lead optimization program around our previously identified triazolopyrimidine-based series of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) inhibitors. The X-ray structure of PfDHODH was used to inform the medicinal chemistry program allowing the identification of a potent and selective inhibitor (DSM265) that acts through DHODH inhibition to kill both sensitive and drug resistant strains of the parasite. This compound has similar potency to chloroquine in the humanized SCID mouse P. falciparum model, can be synthesized by a simple route, and rodent pharmacokinetic studies demonstrated it has excellent oral bioavailability, a long half-life and low clearance. These studies have identified the first candidate in the triazolopyrimidine series to meet previously established progression criteria for efficacy and ADME properties, justifying further development of this compound towards clinical candidate status.
PMCID: PMC3156099  PMID: 21696174
25.  Informing the development of services supporting self-care for severe, long term mental health conditions: a mixed method study of community based mental health initiatives in England 
Supporting self-care is being explored across health care systems internationally as an approach to improving care for long term conditions in the context of ageing populations and economic constraint. UK health policy advocates a range of approaches to supporting self-care, including the application of generic self-management type programmes across conditions. Within mental health, the scope of self-care remains poorly conceptualised and the existing evidence base for supporting self-care is correspondingly disparate. This paper aims to inform the development of support for self-care in mental health by considering how generic self-care policy guidance is implemented in the context of services supporting people with severe, long term mental health problems.
A mixed method study was undertaken comprising standardised psychosocial measures, questionnaires about health service use and qualitative interviews with 120 new referrals to three contrasting community based initiatives supporting self-care for severe, long term mental health problems, repeated nine months later. A framework approach was taken to qualitative analysis, an exploratory statistical analysis sought to identify possible associations between a range of independent variables and self-care outcomes, and a narrative synthesis brought these analyses together.
Participants reported improvement in self-care outcomes (e.g. greater empowerment; less use of Accident and Emergency services). These changes were not associated with level of engagement with self-care support. Level of engagement was associated with positive collaboration with support staff. Qualitative data described the value of different models of supporting self-care and considered challenges. Synthesis of analyses suggested that timing support for self-care, giving service users control over when and how they accessed support, quality of service user-staff relationships and decision making around medication are important issues in supporting self-care in mental health.
Service delivery components – e.g. peer support groups, personal planning – advocated in generic self-care policy have value when implemented in a mental health context. Support for self-care in mental health should focus on core, mental health specific qualities; issues of control, enabling staff-service user relationships and shared decision making. The broad empirical basis of our research indicates the wider relevance of our findings across mental health settings.
PMCID: PMC3468356  PMID: 22769593
Long term conditions; Mental health; Self-care; Self-management; Peer support

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