query: Elevated cell-free mitochondrial DNA levels are associated with mortality.

title: Circulating Mitochondrial DNA in Patients in the ICU as a Marker of Mortality: Derivation and Validation

text:
BACKGROUND Mitochondrial DNA (mtDNA) is a critical activator of inflammation and the innate immune system. However, mtDNA level has not been tested for its role as a biomarker in the intensive care unit (ICU). We hypothesized that circulating cell-free mtDNA levels would be associated with mortality and improve risk prediction in ICU patients.
 METHODS AND FINDINGS Analyses of mtDNA levels were performed on blood samples obtained from two prospective observational cohort studies of ICU patients (the Brigham and Women's Hospital Registry of Critical Illness [BWH RoCI, n = 200] and Molecular Epidemiology of Acute Respiratory Distress Syndrome [ME ARDS, n = 243]). mtDNA levels in plasma were assessed by measuring the copy number of the NADH dehydrogenase 1 gene using quantitative real-time PCR. Medical ICU patients with an elevated mtDNA level (≥3,200 copies/µl plasma) had increased odds of dying within 28 d of ICU admission in both the BWH RoCI (odds ratio [OR] 7.5, 95% CI 3.6-15.8, p = 1×10(-7)) and ME ARDS (OR 8.4, 95% CI 2.9-24.2, p = 9×10(-5)) cohorts, while no evidence for association was noted in non-medical ICU patients. The addition of an elevated mtDNA level improved the net reclassification index (NRI) of 28-d mortality among medical ICU patients when added to clinical models in both the BWH RoCI (NRI 79%, standard error 14%, p<1×10(-4)) and ME ARDS (NRI 55%, standard error 20%, p = 0.007) cohorts. In the BWH RoCI cohort, those with an elevated mtDNA level had an increased risk of death, even in analyses limited to patients with sepsis or acute respiratory distress syndrome. Study limitations include the lack of data elucidating the concise pathological roles of mtDNA in the patients, and the limited numbers of measurements for some of biomarkers.
 CONCLUSIONS Increased mtDNA levels are associated with ICU mortality, and inclusion of mtDNA level improves risk prediction in medical ICU patients. Our data suggest that mtDNA could serve as a viable plasma biomarker in medical ICU patients.

title: Circulating mitochondrial DNA in serum of patients with granulomatosis with polyangiitis.

text: Neutrophil is a key cell in pathophysiology of granulomatosis with polyangiitis. Recently, neutrophil extracellular traps were described in this disease. Mitochondrial DNA is also released during traps formation. We measured circulating cell-free mitochondrial and genomic DNA in serum of patients with granulomatosis with polyangiitis. Subjects with the disease (14 active and 11 in remission stage) and 10 healthy controls were enrolled. Quantitative real-time polymerase chain reaction (PCR) was used to measure 79 base pairs (bp) and 230 bp mtDNA fragments. Alu repeats were quantified to evaluate abundance of nuclear DNA in serum at the presence of plasmid control. Both fragments of mtDNA (79 bp and 230 bp) and genomic DNA were elevated significantly in granulomatosis with polyangiitis compared to controls. Only the shorter 79 bp mtDNA correlated with active stage of granulomatosis with polyangiitis and clinical symptoms. A mechanism of extracellular release of mitochondrial DNA accompanies the active stage of the disease. Circulating mtDNA is extremely high in untreated patients. This suggests that biomarker properties of mtDNA are useful for monitoring of treatment.

title: Effect of lipid restriction on mitochondrial free radical production and oxidative DNA damage.

text: Many studies have shown that caloric restriction (40%) decreases mitochondrial reactive oxygen species (ROS) generation in rodents. Moreover, we have recently found that 7 weeks of 40% protein restriction without strong caloric restriction also decreases ROS production in rat liver. This is interesting since it has been reported that protein restriction can also extend longevity in rodents. In the present study we have investigated the possible role of dietary lipids in the effects of caloric restriction on mitochondrial oxidative stress. Using semipurified diets, the ingestion of lipids in male Wistar rats was decreased by 40% below controls, while the other dietary components were ingested at exactly the same level as in animals fed ad libitum. After 7 weeks of treatment the liver mitochondria of lipid-restricted animals showed significant increases in oxygen consumption with complex I-linked substrates (pyruvate/malate and glutamate/malate). Neither mitochondrial H(2)O(2) production nor oxidative damage to mitochondrial or nuclear DNA was modified in lipid-restricted animals. Oxidative damage to mitochondrial DNA was one order of magnitude higher than that of nuclear DNA in both dietary groups. These results deny a role for lipids and reinforce the possible role of dietary proteins as being responsible for the decrease in mitochondrial ROS production and DNA damage in caloric restriction.

title: BAX/BAK-independent mitoptosis during cell death induced by proteasome inhibition?

text: Proteasome inhibitors induce rapid death of cancer cells. We show that in epithelial cancer cells, such death is associated with dramatic and simultaneous up-regulation of several BH3-only proteins, including BIK, BIM, MCL-1S, NOXA, and PUMA, as well as p53. Elevated levels of these proteins seem to be the result of direct inhibition of their proteasomal degradation, induction of transcription, and active translation. Subsequent cell death is independent of BAX, and probably BAK, and proceeds through the intrinsic mitochondrial apoptosis pathway. We identify the cascade of molecular events responsible for cell death induced by a prototypical proteasome inhibitor, MG132, starting with rapid accumulation of BH3-only proteins in the mitochondria, proceeding through mitochondrial membrane permeabilization and subsequent loss of DeltaPsi(m), and leading to irreversible changes of mitochondrial ultrastructure, degradation of mitochondrial network, and detrimental impairment of crucial mitochondrial functions. Our results also establish a rationale for the broader use of proteasome inhibitors to kill apoptosis-resistant tumor cells that lack functional BAX/BAK proteins.

title: Evaluation of the association between the first observation and the longitudinal change in C-reactive protein, and all-cause mortality.

text:
OBJECTIVE To evaluate the association between vascular inflammation as measured by subacute C-reactive protein (CRP; 1-10 mg/l) and all-cause mortality and the association between change in CRP status (normal <or=3 mg/l and elevated >3 mg/l) and all-cause mortality.
 METHODS Probabilistic record linkage was used to match hospital episode data, laboratory reports and mortality statistics in a large urban population. Survival was evaluated using Cox proportional hazards regression models.
 RESULTS 22 962 patients had their first CRP measurement in the subacute range (1-10 mg/l). Analysis grouped by each additional unit increase in CRP across the subacute range was associated with a 7.3% (95% CI 5.4% to 9.2%) increase in the hazard ratio (HR) of death over 4 years, after controlling for confounding factors (p<0.001). Repeated CRP observations around 1 year apart were recorded in 5811 subjects. After controlling for confounding factors, in patients whose CRP changed from normal (<or=3 mg/l) to elevated (>3 mg/l), the HR increased 6.7-fold (p<0.001) relative to cases whose CRP remained normal. By comparison, among those subjects whose CRP was reduced from elevated to normal, the hazard ratio halved to 3.5 (p = 0.018). In an underpowered analysis of time to cardiovascular events, an identical pattern of risk emerged.
 CONCLUSIONS CRP level predicted all-cause mortality, and additional inclusion of prior change in CRP level and current CRP level more so. Increasing vascular inflammation, as measured by CRP, increases the likelihood of death.

title: The role of red cell distribution width in the prognosis of patients with gastric cancer.

text:
BACKGROUND Although the red cell distribution width (RDW) has been reported as a reliable predictor of prognosis in several types of cancer, to our knowledge the prognostic value of RDW in gastric carcinoma has not been studied, so far.
 OBJECTIVE We aimed to investigate the role of red cell distribution width (RDW) in predicting prognosis in gastric cancer patients.
 METHODS All gastric cancer patients who underwent curative surgery (n= 172, 110M/62F) over a five-year study period were evaluated. Data on demographics, preoperative RDW levels, tumor characteristics (early stage: I and II, advanced stage: IIIA-B-C), disease-free (DFS) and overall survival (OS) were retrospectively reviewed. Patients were classified as high RDW group (RDW ≥ 16, n= 62) or low RDW group (RDW < 16, n= 110).
 RESULTS Overall mortality and postoperative 60-day mortality in both groups were 55% and 14%, respectively. A borderline significant association between RDW (0.063) and mortality was noted. Preoperative RDW levels were significantly higher in patients with short-term mortality (17.9 ± 4.3 vs. 16 ± 3.2, p= 0.015). In high RDW group, the incidence of advanced gastric cancer was significantly higher (75 vs. 51%, p= 0.002), whereas DFS (0.035) and OS (p= 0.04) were lower.
 CONCLUSION The frequency of advanced cancer was high in patients with high RDWvalues. High RDW values were strongly associated with short-term mortality although only a borderline relationship with overall survival was observed.

title: The Antiretroviral Therapy in Lower Income Countries (ART-LINC) Collaboration and ART Cohort Collaboration (ART-CC) groups Summary

text:
BACKGROUND Highly active antiretroviral therapy (HAART) is being scaled up in developing countries. We compared baseline characteristics and outcomes during the first year of HAART between HIV-1-infected patients in low-income and high-income settings.
 METHODS 18 HAART programmes in Africa, Asia, and South America (low-income settings) and 12 HIV cohort studies from Europe and North America (high-income settings) provided data for 4810 and 22,217, respectively, treatment-naïve adult patients starting HAART. All patients from high-income settings and 2725 (57%) patients from low-income settings were actively followed-up and included in survival analyses.
 FINDINGS Compared with high-income countries, patients starting HAART in low-income settings had lower CD4 cell counts (median 108 cells per muL vs 234 cells per muL), were more likely to be female (51%vs 25%), and more likely to start treatment with a non-nucleoside reverse transcriptase inhibitor (NNRTI) (70%vs 23%). At 6 months, the median number of CD4 cells gained (106 cells per muL vs 103 cells per muL) and the percentage of patients reaching HIV-1 RNA levels lower than 500 copies/mL (76%vs 77%) were similar. Mortality was higher in low-income settings (124 deaths during 2236 person-years of follow-up) than in high-income settings (414 deaths during 20,532 person-years). The adjusted hazard ratio (HR) of mortality comparing low-income with high-income settings fell from 4.3 (95% CI 1.6-11.8) during the first month to 1.5 (0.7-3.0) during months 7-12. The provision of treatment free of charge in low-income settings was associated with lower mortality (adjusted HR 0.23; 95% CI 0.08-0.61).
 INTERPRETATION Patients starting HAART in resource-poor settings have increased mortality rates in the first months on therapy, compared with those in developed countries. Timely diagnosis and assessment of treatment eligibility, coupled with free provision of HAART, might reduce this excess mortality.

title: Atm-deficient mice exhibit increased sensitivity to dextran sulfate sodium-induced colitis characterized by elevated DNA damage and persistent immune activation.

text: The role of ataxia telangiectasia mutated (ATM), a DNA double-strand break recognition and response protein, in inflammation and inflammatory diseases is unclear. We have previously shown that high levels of systemic DNA damage are induced by intestinal inflammation in wild-type mice. To determine the effect of Atm deficiency in inflammation, we induced experimental colitis in Atm(-/-), Atm(+/-), and wild-type mice via dextran sulfate sodium (DSS) administration. Atm(-/-) mice had higher disease activity indices and rates of mortality compared with heterozygous and wild-type mice. Systemic DNA damage and immune response were characterized in peripheral blood throughout and after three cycles of treatment. Atm(-/-) mice showed increased sensitivity to levels of DNA strand breaks in peripheral leukocytes, as well as micronucleus formation in erythroblasts, compared with heterozygous and wild-type mice, especially during remission periods and after the end of treatment. Markers of reactive oxygen and nitrogen species-mediated damage, including 8-oxoguanine and nitrotyrosine, were present both in the distal colon and in peripheral leukocytes, with Atm(-/-) mice manifesting more 8-oxoguanine formation than wild-type mice. Atm(-/-) mice showed greater upregulation of inflammatory cytokines and significantly higher percentages of activated CD69+ and CD44+ T cells in the peripheral blood throughout treatment. ATM, therefore, may be a critical immunoregulatory factor dampening the deleterious effects of chronic DSS-induced inflammation, necessary for systemic genomic stability and homeostasis of the gut epithelial barrier.

title: Elevated red blood cell distribution width contributes to poor prognosis in patients undergoing resection for nonmetastatic rectal cancer

text: Several studies have reported that elevated red blood cell distribution width (RDW) was associated with the poor prognosis of different kinds of cancers. The aim of this study was to investigate the prognostic role of RDW in patients undergoing resection for nonmetastatic rectal cancer. We retrospectively reviewed a database of 625 consecutive patients who underwent curative resection for nonmetastatic rectal cancer at our institution from January 2009 to December 2014. The cutoff value of RDW was calculated by receiver-operating characteristic curve. The results demonstrated that patients in high RDW-cv group had a lower overall survival (OS) (P = .018) and disease-free survival (P = .004). We also observed that patients in high RDW-sd group were associated with significantly lower OS (P = .033), whereas the disease-free survival (DFS) was not significantly different (P = .179).In multivariate analysis, we found elevated RDW-cv was associated poor DFS (hazard ratio [HR] = 1.56, P = .010) and RDW-sd can predict a worse OS (HR = 1.70, P = .009).We confirmed that elevated RDW can be an independently prognostic factor in patients undergoing resection for nonmetastatic rectal cancer. So more intervention or surveillance might be paid to the patients with nonmetastatic rectal cancer and elevated RDW values in the future.

title: Genetic Drift Can Compromise Mitochondrial Replacement by Nuclear Transfer in Human Oocytes.

text: Replacement of mitochondria through nuclear transfer between oocytes of two different women has emerged recently as a strategy for preventing inheritance of mtDNA diseases. Although experiments in human oocytes have shown effective replacement, the consequences of small amounts of mtDNA carryover have not been studied sufficiently. Using human mitochondrial replacement stem cell lines, we show that, even though the low levels of heteroplasmy introduced into human oocytes by mitochondrial carryover during nuclear transfer often vanish, they can sometimes instead result in mtDNA genotypic drift and reversion to the original genotype. Comparison of cells with identical oocyte-derived nuclear DNA but different mtDNA shows that either mtDNA genotype is compatible with the nucleus and that drift is independent of mitochondrial function. Thus, although functional replacement of the mitochondrial genome is possible, even low levels of heteroplasmy can affect the stability of the mtDNA genotype and compromise the efficacy of mitochondrial replacement.

title: Mechanisms of pancreatic beta-cell death in type 1 and type 2 diabetes: many differences, few similarities.

text: Type 1 and type 2 diabetes are characterized by progressive beta-cell failure. Apoptosis is probably the main form of beta-cell death in both forms of the disease. It has been suggested that the mechanisms leading to nutrient- and cytokine-induced beta-cell death in type 2 and type 1 diabetes, respectively, share the activation of a final common pathway involving interleukin (IL)-1beta, nuclear factor (NF)-kappaB, and Fas. We review herein the similarities and differences between the mechanisms of beta-cell death in type 1 and type 2 diabetes. In the insulitis lesion in type 1 diabetes, invading immune cells produce cytokines, such as IL-1beta, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma. IL-1beta and/or TNF-alpha plus IFN-gamma induce beta-cell apoptosis via the activation of beta-cell gene networks under the control of the transcription factors NF-kappaB and STAT-1. NF-kappaB activation leads to production of nitric oxide (NO) and chemokines and depletion of endoplasmic reticulum (ER) calcium. The execution of beta-cell death occurs through activation of mitogen-activated protein kinases, via triggering of ER stress and by the release of mitochondrial death signals. Chronic exposure to elevated levels of glucose and free fatty acids (FFAs) causes beta-cell dysfunction and may induce beta-cell apoptosis in type 2 diabetes. Exposure to high glucose has dual effects, triggering initially "glucose hypersensitization" and later apoptosis, via different mechanisms. High glucose, however, does not induce or activate IL-1beta, NF-kappaB, or inducible nitric oxide synthase in rat or human beta-cells in vitro or in vivo in Psammomys obesus. FFAs may cause beta-cell apoptosis via ER stress, which is NF-kappaB and NO independent. Thus, cytokines and nutrients trigger beta-cell death by fundamentally different mechanisms, namely an NF-kappaB-dependent mechanism that culminates in caspase-3 activation for cytokines and an NF-kappaB-independent mechanism for nutrients. This argues against a unifying hypothesis for the mechanisms of beta-cell death in type 1 and type 2 diabetes and suggests that different approaches will be required to prevent beta-cell death in type 1 and type 2 diabetes.

title: ER-associated mitochondrial division links the distribution of mitochondria and mitochondrial DNA in yeast

text: Mitochondrial division is important for mitochondrial distribution and function. Recent data have demonstrated that ER-mitochondria contacts mark mitochondrial division sites, but the molecular basis and functions of these contacts are not understood. Here we show that in yeast, the ER-mitochondria tethering complex, ERMES, and the highly conserved Miro GTPase, Gem1, are spatially and functionally linked to ER-associated mitochondrial division. Gem1 acts as a negative regulator of ER-mitochondria contacts, an activity required for the spatial resolution and distribution of newly generated mitochondrial tips following division. Previous data have demonstrated that ERMES localizes with a subset of actively replicating mitochondrial nucleoids. We show that mitochondrial division is spatially linked to nucleoids and that a majority of these nucleoids segregate prior to division, resulting in their distribution into newly generated tips in the mitochondrial network. Thus, we postulate that ER-associated division serves to link the distribution of mitochondria and mitochondrial nucleoids in cells. DOI:http://dx.doi.org/10.7554/eLife.00422.001.

title: The cell cycle in polyploid megakaryocytes is associated with reduced activity of cyclin B1-dependent cdc2 kinase.

text: The platelet precursor, the megakaryocyte, matures to a polyploid cell as a result of DNA replication in the absence of mitosis (endomitosis). The factors controlling endomitosis are accessible to analysis in our megakaryocytic cell line, MegT, generated by targeted expression of temperature-sensitive simian virus 40 large T antigen to megakaryocytes of transgenic mice. We aimed to define whether endomitosis consists of a continuous phase of DNA synthesis (S) or of S phases interrupted by gaps. Analysis of the cell cycle in MegT cells revealed that, upon inactivation of large T antigen, the cells shifted from a mitotic cell cycle to an endomitotic cell cycle consisting of S/Gap phases. The level of the G1/S cyclin, cyclin A, as well as of the G1 phase cyclin, cyclin D3, were elevated at the onset of DNA synthesis, either in MegT cells undergoing a mitotic cell cycle or during endomitosis. In contrast, the level of the mitotic cyclin, cyclin B1, cycled in cells displaying a mitotic cell cycle while not detectable during endomitosis. Comparable levels of the mitotic kinase protein, Cdc2, were detected during the mitotic cell cycle or during endomitosis; however, cyclin B1-dependent Cdc2 kinase activity was largely abolished in the polyploid cells. Fibroblasts immortalized with the same heat-labile oncogene do not display reduced levels of cyclin B1 upon shifting to high temperature nor do they become polyploid, indicating that reduced levels of cyclin B1 is a property of megakaryocytes and not of the T-antigen mutant. We conclude that cellular programming during endoreduplication in megakaryocytes is associated with reduced levels of cyclin B1.

title: Oxygen Metabolism Causes Chromosome Breaks and Is Associated with the Neuronal Apoptosis Observed in DNA Double-Strand Break Repair Mutants

text: Cells deficient in a major DNA double-strand break repair pathway (nonhomologous DNA end joining [NHEJ]) have increased spontaneous chromosome breaks; however, the source of these chromosome breaks has remained undefined. Here, we show that the observed spontaneous chromosome breaks are partially suppressed by reducing the cellular oxygen tension. Conversely, elevating the level of reactive oxygen species by overexpressing the antioxidant enzyme superoxide dismutase 1 (SOD1), in a transgenic mouse, increases chromosome breakage. The effect of SOD1 can also be modulated by cellular oxygen tension. The elevated chromosome breakage correlates histologically with a significant increase in the amount of neuronal cell death in Ku86(-/-) SOD1 transgenic embryos over that seen in Ku86(-/-) embryos. Therefore, oxygen metabolism is a major source of the genomic instability observed in NHEJ-deficient cells and, presumably, in all cells.

title: Oxidative stress in cancer associated fibroblasts drives tumor-stroma co-evolution: A new paradigm for understanding tumor metabolism, the field effect and genomic instability in cancer cells.

text: Loss of stromal fibroblast caveolin-1 (Cav-1) is a powerful single independent predictor of poor prognosis in human breast cancer patients, and is associated with early tumor recurrence, lymph node metastasis and tamoxifen-resistance. We developed a novel co-culture system to understand the mechanism(s) by which a loss of stromal fibroblast Cav-1 induces a "lethal tumor micro-environment. " Here, we propose a new paradigm to explain the powerful prognostic value of stromal Cav-1. In this model, cancer cells induce oxidative stress in cancer-associated fibroblasts, which then acts as a "metabolic" and "mutagenic" motor to drive tumor-stroma co-evolution, DNA damage and aneuploidy in cancer cells. More specifically, we show that an acute loss of Cav-1 expression leads to mitochondrial dysfunction, oxidative stress and aerobic glycolysis in cancer associated fibroblasts. Also, we propose that defective mitochondria are removed from cancer-associated fibroblasts by autophagy/mitophagy that is induced by oxidative stress. As a consequence, cancer associated fibroblasts provide nutrients (such as lactate) to stimulate mitochondrial biogenesis and oxidative metabolism in adjacent cancer cells (the "Reverse Warburg Effect"). We provide evidence that oxidative stress in cancer-associated fibroblasts is sufficient to induce genomic instability in adjacent cancer cells, via a bystander effect, potentially increasing their aggressive behavior. Finally, we directly demonstrate that nitric oxide (NO) over-production, secondary to Cav-1 loss, is the root cause for mitochondrial dysfunction in cancer associated fibroblasts. In support of this notion, treatment with anti-oxidants (such as N-acetyl-cysteine, metformin and quercetin) or NO inhibitors (L-NAME) was sufficient to reverse many of the cancer-associated fibroblast phenotypes that we describe. Thus, cancer cells use "oxidative stress" in adjacent fibroblasts (i) as an "engine" to fuel their own survival via the stromal production of nutrients and (ii) to drive their own mutagenic evolution towards a more aggressive phenotype, by promoting genomic instability. We also present evidence that the "field effect" in cancer biology could also be related to the stromal production of ROS and NO species. eNOS-expressing fibroblasts have the ability to downregulate Cav-1 and induce mitochondrial dysfunction in adjacent fibroblasts that do not express eNOS. As such, the effects of stromal oxidative stress can be laterally propagated, amplified and are effectively "contagious"--spread from cell-to-cell like a virus--creating an "oncogenic/mutagenic" field promoting widespread DNA damage.

title: Obesity, type 2 diabetes, and cancer: the insulin and IGF connection.

text: Epidemiological studies suggest a positive association between obesity and type 2 diabetes mellitus (T2D) with the risk of cancer and cancer-related mortality. Insulin resistance, hyperinsulinemia, increased levels of IGF, elevated levels of steroid and peptide hormones, and inflammatory markers appear to play a role in the connection between these different diseases. Medications, such as metformin and exogenous insulin, used to treat T2D may affect the risk of cancer and cancer-related mortality. Newer therapies targeting the insulin and IGF1 systems are being developed for use in cancer therapy.

title: Nitrite protects against morbidity and mortality associated with TNF- or LPS-induced shock in a soluble guanylate cyclase–dependent manner

text: Nitrite (NO(2)(-)), previously viewed as a physiologically inert metabolite and biomarker of the endogenous vasodilator NO, was recently identified as an important biological NO reservoir in vasculature and tissues, where it contributes to hypoxic signaling, vasodilation, and cytoprotection after ischemia-reperfusion injury. Reduction of nitrite to NO may occur enzymatically at low pH and oxygen tension by deoxyhemoglobin, deoxymyoglobin, xanthine oxidase, mitochondrial complexes, or NO synthase (NOS). We show that nitrite treatment, in sharp contrast with the worsening effect of NOS inhibition, significantly attenuates hypothermia, mitochondrial damage, oxidative stress and dysfunction, tissue infarction, and mortality in a mouse shock model induced by a lethal tumor necrosis factor challenge. Mechanistically, nitrite-dependent protection was not associated with inhibition of mitochondrial complex I activity, as previously demonstrated for ischemia-reperfusion, but was largely abolished in mice deficient for the soluble guanylate cyclase (sGC) alpha1 subunit, one of the principal intracellular NO receptors and signal transducers in the cardiovasculature. Nitrite could also provide protection against toxicity induced by Gram-negative lipopolysaccharide, although higher doses were required. In conclusion, we show that nitrite can protect against toxicity in shock via sGC-dependent signaling, which may include hypoxic vasodilation necessary to maintain microcirculation and organ function, and cardioprotection.

title: Dementia incidence and mortality in middle-income countries, and associations with indicators of cognitive reserve: a 10/66 Dementia Research Group population-based cohort study

text:
BACKGROUND Results of the few cohort studies from countries with low incomes or middle incomes suggest a lower incidence of dementia than in high-income countries. We assessed incidence of dementia according to criteria from the 10/66 Dementia Research Group and Diagnostic and Statistical Manual of Mental Disorders (DSM) IV, the effect of dementia at baseline on mortality, and the independent effects of age, sex, socioeconomic position, and indicators of cognitive reserve.
 METHODS We did a population-based cohort study of all people aged 65 years and older living in urban sites in Cuba, the Dominican Republic, and Venezuela, and rural and urban sites in Peru, Mexico, and China, with ascertainment of incident 10/66 and DSM-IV dementia 3-5 years after cohort inception. We used questionnaires to obtain information about age in years, sex, educational level, literacy, occupational attainment, and number of household assets. We obtained information about mortality from all sites. For participants who had died, we interviewed a friend or relative to ascertain the likelihood that they had dementia before death.
 FINDINGS 12,887 participants were interviewed at baseline. 11,718 were free of dementia, of whom 8137 (69%) were reinterviewed, contributing 34,718 person-years of follow-up. Incidence for 10/66 dementia varied between 18·2 and 30·4 per 1000 person-years, and were 1·4-2·7 times higher than were those for DSM-IV dementia (9·9-15·7 per 1000 person-years). Mortality hazards were 1·56-5·69 times higher in individuals with dementia at baseline than in those who were dementia-free. Informant reports suggested a high incidence of dementia before death; overall incidence might be 4-19% higher if these data were included. 10/66 dementia incidence was independently associated with increased age (HR 1·67; 95% CI 1·56-1·79), female sex (0·72; 0·61-0·84), and low education (0·89; 0·81-0·97), but not with occupational attainment (1·04; 0·95-1·13).
 INTERPRETATION Our results provide supportive evidence for the cognitive reserve hypothesis, showing that in middle-income countries as in high-income countries, education, literacy, verbal fluency, and motor sequencing confer substantial protection against the onset of dementia.
 FUNDING Wellcome Trust Health Consequences of Population Change Programme, WHO, US Alzheimer's Association, FONACIT/ CDCH/ UCV.

title: Association between CYP2D6 polymorphisms and outcomes among women with early stage breast cancer treated with tamoxifen.

text:
CONTEXT The growth inhibitory effect of tamoxifen, which is used for the treatment of hormone receptor-positive breast cancer, is mediated by its metabolites, 4-hydroxytamoxifen and endoxifen. The formation of active metabolites is catalyzed by the polymorphic cytochrome P450 2D6 (CYP2D6) enzyme.
 OBJECTIVE To determine whether CYP2D6 variation is associated with clinical outcomes in women receiving adjuvant tamoxifen.
 DESIGN, SETTING, AND PATIENTS Retrospective analysis of German and US cohorts of patients treated with adjuvant tamoxifen for early stage breast cancer. The 1325 patients had diagnoses between 1986 and 2005 of stage I through III breast cancer and were mainly postmenopausal (95.4%). Last follow-up was in December 2008; inclusion criteria were hormone receptor positivity, no metastatic disease at diagnosis, adjuvant tamoxifen therapy, and no chemotherapy. DNA from tumor tissue or blood was genotyped for CYP2D6 variants associated with reduced (*10, *41) or absent (*3, *4, *5) enzyme activity. Women were classified as having an extensive (n=609), heterozygous extensive/intermediate (n=637), or poor (n=79) CYP2D6 metabolism.
 MAIN OUTCOME MEASURES Time to recurrence, event-free survival, disease-free survival, and overall survival.
 RESULTS Median follow-up was 6.3 years. At 9 years of follow-up, the recurrence rates were 14.9% for extensive metabolizers, 20.9% for heterozygous extensive/intermediate metabolizers, and 29.0% for poor metabolizers, and all-cause mortality rates were 16.7%, 18.0%, and 22.8%, respectively. Compared with extensive metabolizers, there was a significantly increased risk of recurrence for heterozygous extensive/intermediate metabolizers (time to recurrence adjusted hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.04-1.90) and for poor metabolizers (time to recurrence HR, 1.90; 95% CI, 1.10-3.28). Compared with extensive metabolizers, those with decreased CYP2D6 activity (heterozygous extensive/intermediate and poor metabolism) had worse event-free survival (HR, 1.33; 95% CI, 1.06-1.68) and disease-free survival (HR, 1.29; 95% CI, 1.03-1.61), but there was no significant difference in overall survival (HR, 1.15; 95% CI, 0.88-1.51).
 CONCLUSION Among women with breast cancer treated with tamoxifen, there was an association between CYP2D6 variation and clinical outcomes, such that the presence of 2 functional CYP2D6 alleles was associated with better clinical outcomes and the presence of nonfunctional or reduced-function alleles with worse outcomes.

title: Cell death from antibiotics without the involvement of reactive oxygen species.

text: Recent observations have suggested that classic antibiotics kill bacteria by stimulating the formation of reactive oxygen species (ROS). If true, this notion might guide new strategies to improve antibiotic efficacy. In this study, the model was directly tested. Contrary to the hypothesis, antibiotic treatment did not accelerate the formation of hydrogen peroxide in Escherichia coli and did not elevate intracellular free iron, an essential reactant for the production of lethal damage. Lethality persisted in the absence of oxygen, and DNA repair mutants were not hypersensitive, undermining the idea that toxicity arose from oxidative DNA lesions. We conclude that these antibiotic exposures did not produce ROS and that lethality more likely resulted from the direct inhibition of cell-wall assembly, protein synthesis, and DNA replication.


query: Eliminating the last sporadic cases of malaria requires considerable funding.

title: Costs and financial feasibility of malaria elimination

text: The marginal costs and benefits of converting malaria programmes from a control to an elimination goal are central to strategic decisions, but empirical evidence is scarce. We present a conceptual framework to assess the economics of elimination and analyse a central component of that framework-potential short-term to medium-term financial savings. After a review that showed a dearth of existing evidence, the net present value of elimination in five sites was calculated and compared with effective control. The probability that elimination would be cost-saving over 50 years ranged from 0% to 42%, with only one site achieving cost-savings in the base case. These findings show that financial savings should not be a primary rationale for elimination, but that elimination might still be a worthy investment if total benefits are sufficient to outweigh marginal costs. Robust research into these elimination benefits is urgently needed.

title: The feasibility of malaria elimination in South Africa

text:
BACKGROUND Following the last major malaria epidemic in 2000, malaria incidence in South Africa has declined markedly. The decrease has been so emphatic that South Africa now meets the World Health Organization (WHO) threshold for malaria elimination. Given the Millennium Development Goal of reversing the spread of malaria by 2015, South Africa is being urged to adopt an elimination agenda. This study aimed to determine the appropriateness of implementing a malaria elimination programme in present day South Africa.
 METHODS An assessment of the progress made by South Africa in terms of implementing an integrated malaria control programme across the three malaria-endemic provinces was undertaken. Vector control and case management data were analysed from the period of 2000 until 2011.
 RESULTS Both malaria-related morbidity and mortality have decreased significantly across all three malaria-endemic provinces since 2000. The greatest decline was seen in KwaZulu-Natal where cases decreased from 42,276 in 2000 to 380 in 2010 and deaths dropped from 122 in 2000 to six in 2010. Although there has been a 49.2 % (8,553 vs 4,214) decrease in the malaria cases reported in Limpopo Province, currently it is the largest contributor to the malaria incidence in South Africa. Despite all three provinces reporting average insecticide spray coverage of over 80%, malaria incidence in both Mpumalanga and Limpopo remains above the elimination threshold. Locally transmitted case numbers have declined in all three malaria provinces but imported case numbers have been increasing. Knowledge gaps in vector distribution, insecticide resistance status and drug usage were also identified.
 CONCLUSIONS Malaria elimination in South Africa is a realistic possibility if certain criteria are met. Firstly, there must be continued support for the existing malaria control programmes to ensure the gains made are sustained. Secondly, cross border malaria control initiatives with neighbouring countries must be strongly encouraged and supported to reduce malaria in the region and the importation of malaria into South Africa. Thirdly, operational research, particularly on vector distribution and insecticide resistance status must be conducted as a matter of urgency, and finally, the surveillance systems must be refined to ensure the information required to inform an elimination agenda are routinely collected.

title: Lessons learnt from malaria epidemics in the Islamic Republic of Iran.

text: The Islamic Republic of Iran is in the pre-elimination phase of malaria control, but malaria epidemics are still a concern in the south of the country. This retrospective study presents the epidemiological characteristics and predisposing factors of 60 of the malaria epidemics reported in Sistan va Baluchestan province during 2005-09. A zero-truncated negative binomial model was used to investigate the relation between predictor variables and the total number of malaria cases. Malaria epidemics occurred mainly in the southern part of the province, mostly between July and October, peaking in August. Most malaria epidemics were small-scale (68.3% were < 100 cases) and short (51.7% lasted < 1 month). Plasmodium falciparum was present in 46.7% of the epidemics. An increase in the rainfall rate as well as population movements were the most significant predisposing factors. The results may help inform an epidemic investigation and reporting system as the country approaches the malaria elimination phase.

title: Determination of Malaria Epidemiological Status in Iran’s Malarious Areas as Baseline Information for Implementation of Malaria Elimination Program in Iran

text:
BACKGROUND According to willingness of the Ministry of Health, Iran and presence of appropriate conditions for disease elimination, national malaria control program decided to conduct a research to clarify malaria status in 2007 and to provide required information to perform the elimination program. This review is comprised of the basis of national malaria elimination program in vision of 2025, which was started in 2010.
 METHODS In this descriptive study, data were analyzed by applications of different variables at district level. All districts in the three south eastern provinces, in which malaria has local transmission, were considered. Malaria cases has been determined and studied based on the national malaria surveillance system.
 RESULTS Since vivax malaria is predominant in Sistan & Baluchestan Province, number of vivax cases is equal to malaria positive cases approximately. The important point is that Nikshahr contains the maximum number of local vivax cases in this province and the maximum number of falciparum cases is reported from Sarbaz district. Among all districts of Hormozgan Province, no case of autochthonous falciparum was detected except in Bandar Jask and one case in Minab. There was no case of autochthonous falciparum in Kerman Province, except in Kahnoj and Ghale Ganj that each of them had one case in 2007.
 CONCLUSION It appears that the report of locally transmitted cases in Iran is increasing over the past few years, before starting malaria elimination plan. Since the Afghan refugees started to return to their own country so the main source of reporting of imported malaria cases reduced and local cases would be demonstrated more clearly.

title: Ecology, economics and political will: the vicissitudes of malaria strategies in Asia.

text: The documented history of malaria in parts of Asia goes back more than 2,000 years, during which the disease has been a major player on the socioeconomic stage in many nation states as they waxed and waned in power and prosperity. On a much shorter time scale, the last half century has seen in microcosm a history of large fluctuations in endemicity and impact of malaria across the spectrum of rice fields and rain forests, mountains and plains that reflect the vast ecological diversity inhabited by this majority aggregation of mankind. That period has seen some of the most dramatic changes in social and economic structure, in population size, density and mobility, and in political structure in history: all have played a part in the changing face of malaria in this extensive region of the world. While the majority of global malaria cases currently reside in Africa, greater numbers inhabited Asia earlier this century before malaria programs savored significant success, and now Asia harbors a global threat in the form of the epicenter of multidrug resistant Plasmodium falciparum which is gradually encompassing the tropical world. The latter reflects directly the vicissitudes of economic change over recent decades, particularly the mobility of populations in search of commerce, trade and personal fortunes, or caught in the misfortunes of physical conflicts. The period from the 1950s to the 1990s has witnessed near "eradication" followed by resurgence of malaria in Sri Lanka, control and resurgence in India, the influence of war and postwar instability on drug resistance in Cambodia, increase in severe and cerebral malaria in Myanmar during prolonged political turmoil, the essential disappearance of the disease from all but forested border areas of Thailand where it remains for the moment intractable, the basic elimination of vivax malaria from many provinces of central China. Both positive and negative experiences have lessons to teach in the debate between eradication and control as alternative strategies. China has for years held high the goal of "basic elimination", eradication by another name, in sensible semi-defiance of WHO dictates. The Chinese experience makes it clear that, given community organization, exhaustive attention to case detection, management and focus elimination, plus the political will at all levels of society, it is possible both to eliminate malaria from large areas of an expansive nation and to implement surveillance necessary to maintain something approaching eradication status in those areas. But China has not succeeded in the international border regions of the tropical south where unfettered population movement confounds the program. Thailand, Malaysia and to an extent Vietnam have also reached essential elimination in their rice field plains by vigorous vertical programs but fall short at their forested borders. Economics is central to the history of the rise and fall of nations, and to the history of disease in the people who constitute nations. The current love affair with free market economics as the main driving force for advance of national wealth puts severe limitations on the essential involvement of communities in malaria management. The task of malaria control or elimination needs to be clearly related to the basic macroeconomic process that preoccupies governments, not cloistered away in the health sector Historically malaria has had a severe, measurable, negative impact on the productivity of nations. Economic models need rehoning with political aplomb and integrating with technical and demographic strategies. Recent decades in Chinese malaria history carry some lessons that may be relevant in this context.

title: How absolute is zero? An evaluation of historical and current definitions of malaria elimination

text: Decisions to eliminate malaria from all or part of a country involve a complex set of factors, and this complexity is compounded by ambiguity surrounding some of the key terminology, most notably "control" and "elimination. " It is impossible to forecast resource and operational requirements accurately if endpoints have not been defined clearly, yet even during the Global Malaria Eradication Program, debate raged over the precise definition of "eradication. " Analogous deliberations regarding the meaning of "elimination" and "control" are basically nonexistent today despite these terms' core importance to programme planning. To advance the contemporary debate about these issues, this paper presents a historical review of commonly used terms, including control, elimination, and eradication, to help contextualize current understanding of these concepts. The review has been supported by analysis of the underlying mathematical concepts on which these definitions are based through simple branching process models that describe the proliferation of malaria cases following importation. Through this analysis, the importance of pragmatic definitions that are useful for providing malaria control and elimination programmes with a practical set of strategic milestones is emphasized, and it is argued that current conceptions of elimination in particular fail to achieve these requirements. To provide all countries with precise targets, new conceptual definitions are suggested to more precisely describe the old goals of "control" - here more exactly named "controlled low-endemic malaria" - and "elimination. " Additionally, it is argued that a third state, called "controlled non-endemic malaria," is required to describe the epidemiological condition in which endemic transmission has been interrupted, but malaria resulting from onwards transmission from imported infections continues to occur at a sufficiently high level that elimination has not been achieved. Finally, guidelines are discussed for deriving the separate operational definitions and metrics that will be required to make these concepts relevant, measurable, and achievable for a particular environment.

title: Malaria eradication back on the table.

text: After a lapse of almost 40 years, malaria eradication is back on the global health agenda. Inspired by the Gates Malaria Forum in October 2007,1,2 key organizations are starting to debate the pros and cons of redefining eradication as an explicit goal of malaria control efforts. Attempts to eliminate malaria in southern Africa3 and Pacific Island states,4 and WHO’s Global Malaria Programme agenda and field manual for malaria elimination,5,6 foreshadow this movement towards another global attempt at eradication.     When marking 60 years of WHO’s commitment to fighting malaria, we must ask what has been achieved, but also what can we learn from the past. We now know so much more about the biology of parasite-host responses, the determinants of endemicity and transmission dynamics, the social, economic and cultural implications of malaria at household, community and national levels, and the demands made upon health systems in endemic countries. We do not yet know how to synthesize and integrate this knowledge to achieve elimination in different settings.     Regional malaria elimination campaigns were first conducted in the late 1940s, preparing the ground for the Global Malaria Eradication Program in 1955. This campaign succeeded in eliminating malaria from Europe, North America, the Caribbean and parts of Asia and South-Central America.7 But no major success occurred in sub-Saharan Africa, which accounts for 80% of today’s burden of malaria.8 When the aspiration of global eradication was abandoned in 1969, the main reasons for failure were technical challenges of executing the strategy especially in Africa.     The post-eradication era from 1969 to 1991 focused on technical issues, and research and development for new tools, leading to advances in drug and vaccine development, vector control and insecticide-treated nets. These decades also brought a better understanding of the social, economic and cultural dimensions of malaria. There was little global support provided specifically for malaria control in the newly independent states of Africa that were struggling to establish broad-based health systems and primary health care. By 1992, the combination of a worsening malaria situation and promising technical developments led to renewed global focus on malaria control.     The Roll Back Malaria initiative, launched by WHO in 1998, led to the Abuja Declaration in 2000, which defined progressive intervention coverage targets for control designed to eliminate malaria as a public health problem, while emphasizing that this could only be achieved through vastly strengthened local health systems.9 Increased resources through the Global Fund to Fight AIDS, Tuberculosis and Malaria, the World Bank’s Booster Program, the US President’s Malaria Initiative and many others has meant that this page is finally beginning to turn as intervention coverage is rising.10    It is against this background that we hear this call for elimination/eradication. The challenges remain formidable. We all know that elimination in Africa is not possible with current tools. But efforts must focus beyond simply developing better tools, to include how existing and future tools can be strategically combined for maximum synergistic effectiveness when integrated into different health and social systems prevailing in endemic areas. Aiming at elimination and eradication further implies the need for effective surveillance strategies to monitor progress (again a challenge for health systems). This in turn requires a better understanding of malaria transmission heterogeneity in a globalized world with rapidly changing dynamics in environment, climate, migration and transnational cooperation.     Maintaining long-term momentum in the face of success in regional elimination while waiting to achieve final eradication will be a major challenge. Shrinking the map by starting on the malaria margins with the “easy-to-eliminate” settings will boost morale initially but may bring marginal benefits to such areas at the expense of those where the burden of malaria is highest. Any strategic plan – and here we learn again from the past – needs to be a synchronous global effort, locally adapted in all endemic areas.     Although we lack sufficient knowledge, systems and tools to eradicate malaria today, we do have a window of political will and financial resources to refocus on the goal of effective control through universal coverage of appropriate interventions. The prerequisites for a successful start are: (i) a process of inclusive discourse to agree on global vision, goals and strategy; and (ii) a global plan for all endemic areas describing how, where and when we move from control towards elimination. What must distinguish the new era, especially in Africa, is a real rather than rhetorical emphasis on health systems. ■

title: Optimising Strategies for Plasmodium falciparum Malaria Elimination in Cambodia: Primaquine, Mass Drug Administration and Artemisinin Resistance

text:
BACKGROUND Malaria elimination requires a variety of approaches individually optimized for different transmission settings. A recent field study in an area of low seasonal transmission in South West Cambodia demonstrated dramatic reductions in malaria parasite prevalence following both mass drug administration (MDA) and high treatment coverage of symptomatic patients with artemisinin-piperaquine plus primaquine. This study employed multiple combined strategies and it was unclear what contribution each made to the reductions in malaria.
 METHOD AND FINDINGS A mathematical model fitted to the trial results was used to assess the effects of the various components of these interventions, design optimal elimination strategies, and explore their interactions with artemisinin resistance, which has recently been discovered in Western Cambodia. The modelling indicated that most of the initial reduction of P. falciparum malaria resulted from MDA with artemisinin-piperaquine. The subsequent continued decline and near elimination resulted mainly from high coverage with artemisinin-piperaquine treatment. Both these strategies were more effective with the addition of primaquine. MDA with artemisinin combination therapy (ACT) increased the proportion of artemisinin resistant infections, although much less than treatment of symptomatic cases with ACT, and this increase was slowed by adding primaquine. Artemisinin resistance reduced the effectiveness of interventions using ACT when the prevalence of resistance was very high. The main results were robust to assumptions about primaquine action, and immunity.
 CONCLUSIONS The key messages of these modelling results for policy makers were: high coverage with ACT treatment can produce a long-term reduction in malaria whereas the impact of MDA is generally only short-term; primaquine enhances the effect of ACT in eliminating malaria and reduces the increase in proportion of artemisinin resistant infections; parasite prevalence is a better surveillance measure for elimination programmes than numbers of symptomatic cases; combinations of interventions are most effective and sustained efforts are crucial for successful elimination.

title: Challenges for malaria elimination in Zanzibar: pyrethroid resistance in malaria vectors and poor performance of long-lasting insecticide nets

text:
BACKGROUND Long-lasting insecticide treated nets (LLINs) and indoor residual house spraying (IRS) are the main interventions for the control of malaria vectors in Zanzibar. The aim of the present study was to assess the susceptibility status of malaria vectors against the insecticides used for LLINs and IRS and to determine the durability and efficacy of LLINs on the island.
 METHODS Mosquitoes were sampled from Pemba and Unguja islands in 2010-2011 for use in WHO susceptibility tests. One hundred and fifty LLINs were collected from households on Unguja, their physical state was recorded and then tested for efficacy as well as total insecticide content.
 RESULTS Species identification revealed that over 90% of the Anopheles gambiae complex was An. arabiensis with a small number of An. gambiae s.s. and An. merus being present. Susceptibility tests showed that An. arabiensis on Pemba was resistant to the pyrethroids used for LLINs and IRS. Mosquitoes from Unguja Island, however, were fully susceptible to all pyrethroids tested. A physical examination of 150 LLINs showed that two thirds were damaged after only three years in use. All used nets had a significantly lower (p < 0.001) mean permethrin concentration of 791.6 mg/m2 compared with 944.2 mg/m2 for new ones. Their efficacy decreased significantly against both susceptible An. gambiae s.s. colony mosquitoes and wild-type mosquitoes from Pemba after just six washes (p < 0.001).
 CONCLUSION The sustainability of the gains achieved in malaria control in Zanzibar is seriously threatened by the resistance of malaria vectors to pyrethroids and the short-lived efficacy of LLINs. This study has revealed that even in relatively well-resourced and logistically manageable places like Zanzibar, malaria elimination is going to be difficult to achieve with the current control measures.

title: The last and the next hundred years of malariology.

text: The founding fathers of malariology combined scientific originality, perseverance in research, strong characters, breadth of interest and social concern. A hundred years later research and understanding has made immense progress but the world still bears a huge burden of malaria. For the next century research requires both more specialism and a holistic range if it is to be used in control, requiring multidisciplinary team work. Environmental changes and interventions produce a dynamic and changing pattern of malaria, not the static one of the past. From the original parasite life cycle, research has analysed a series of other cycles at electron microscope, biochemical and genome levels on decreasing size scales and quantitative epidemiological cycles for control. Recent additions to these concepts have been stage-specific antigens, cycles of disease rather than parasites alone, considering populations of parasites rather than just cases, and also genetic variation in each component of the parasite-human host-vector triad. In this volume there emerges for the first time a coherent overall picture of the biomedical aspects of basic malariology as the interacting population genetics of malaria parasites, anophelines and people. This provides a coherent model for the new century dealing with the great biological malaria problems of drug resistance, vaccine development, insecticidal and net control and can feed, with socio-economic work, into the gathering renewal of control efforts. New work on large-scale changes of malaria in space and time enables us to be precise about effects of local and global environmental changes to predict epidemics. Future research will be as much about linking these different scales of understanding as control will be about linking different levels of the health system. The grim situation in poor holoendemic countries also requires practical support of the type that the founders of malariology were involved in. A coherent understanding needs to feed into the new control efforts, from Roll Back Malaria onwards, for the next century.

title: Reducing Plasmodium falciparum Malaria Transmission in Africa: A Model-Based Evaluation of Intervention Strategies

text:
BACKGROUND Over the past decade malaria intervention coverage has been scaled up across Africa. However, it remains unclear what overall reduction in transmission is achievable using currently available tools.
 METHODS AND FINDINGS We developed an individual-based simulation model for Plasmodium falciparum transmission in an African context incorporating the three major vector species (Anopheles gambiae s.s., An. arabiensis, and An. funestus) with parameters obtained by fitting to parasite prevalence data from 34 transmission settings across Africa. We incorporated the effect of the switch to artemisinin-combination therapy (ACT) and increasing coverage of long-lasting insecticide treated nets (LLINs) from the year 2000 onwards. We then explored the impact on transmission of continued roll-out of LLINs, additional rounds of indoor residual spraying (IRS), mass screening and treatment (MSAT), and a future RTS,S/AS01 vaccine in six representative settings with varying transmission intensity (as summarized by the annual entomological inoculation rate, EIR: 1 setting with low, 3 with moderate, and 2 with high EIRs), vector-species combinations, and patterns of seasonality. In all settings we considered a realistic target of 80% coverage of interventions. In the low-transmission setting (EIR approximately 3 ibppy [infectious bites per person per year]), LLINs have the potential to reduce malaria transmission to low levels (<1% parasite prevalence in all age-groups) provided usage levels are high and sustained. In two of the moderate-transmission settings (EIR approximately 43 and 81 ibppy), additional rounds of IRS with DDT coupled with MSAT could drive parasite prevalence below a 1% threshold. However, in the third (EIR = 46) with An. arabiensis prevailing, these interventions are insufficient to reach this threshold. In both high-transmission settings (EIR approximately 586 and 675 ibppy), either unrealistically high coverage levels (>90%) or novel tools and/or substantial social improvements will be required, although considerable reductions in prevalence can be achieved with existing tools and realistic coverage levels.
 CONCLUSIONS Interventions using current tools can result in major reductions in P. falciparum malaria transmission and the associated disease burden in Africa. Reduction to the 1% parasite prevalence threshold is possible in low- to moderate-transmission settings when vectors are primarily endophilic (indoor-resting), provided a comprehensive and sustained intervention program is achieved through roll-out of interventions. In high-transmission settings and those in which vectors are mainly exophilic (outdoor-resting), additional new tools that target exophagic (outdoor-biting), exophilic, and partly zoophagic mosquitoes will be required.

title: Do physicians follow systemic treatment and funding policy guidelines?

text:
BACKGROUND The use of bisphosphonates for the prevention of skeletal related events in women with bone metastases from breast cancer is well established. We undertook an evaluation of bisphosphonate use in clinical practice in three Canadian cancer centres. In addition we assessed whether or not physicians at these centres are following their local treatment guidelines and funding policies.
 METHODS Charts and electronic files of patients who had received either clodronate or pamidronate at any time between January 2000 and December 2001 at three Canadian cancer centres were retrospectively reviewed.
 RESULTS There has been a marked improvement in the time between the diagnosis of bone metastases and the commencement of bisphosphonates from a median of 155 days in 1998 to 24 days in 2001. However, despite a local funding policy requiring that oral clodronate be the first bisphosphonate used, this was the case in only 67% of patients. In addition, despite one centre's guidelines recommending that bisphosphonates be stopped once the patient was progressing, 90% of their patients remained on bisphosphonates until they died.
 CONCLUSIONS A considerable amount of effort is spent on the creation of "evidence based" treatment guidelines. Funding agencies develop policies based on these treatment guidelines, but often funding is more restrictive than the treatment guideline would suggest. It is clear from this review that physicians still appear to manage a substantial proportion of patients outside of funding policies, but within evidence based recommendations. Therefore, a need exists for either the creation of guidelines and policies that physicians will follow or the implementation of methods to ensure that restrictive policies are actually followed.

title: Population dynamics of a pathogen: the conundrum of vivax malaria

text: Building a mathematical model of population dynamics of pathogens within their host involves considerations of factors similar to those in ecology, as pathogens can prey on cells in the host. But within the multicellular host, attacked cell types are integrated with other cellular systems, which in turn intervene in the infection. For example, immune responses attempt to sense and then eliminate or contain pathogens, and homeostatic mechanisms try to compensate for cell loss. This review focuses on modeling applied to malarias, diseases caused by single-cell eukaryote parasites that infect red blood cells, with special concern given to vivax malaria, a disease often thought to be benign (if sometimes incapacitating) because the parasite only attacks a small proportion of red blood cells, the very youngest ones. However, I will use mathematical modeling to argue that depletion of this pool of red blood cells can be disastrous to the host if growth of the parasite is not vigorously check by host immune responses. Also, modeling can elucidate aspects of new field observations that indicate that vivax malaria is more dangerous than previously thought. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12551-010-0034-3) contains supplementary material, which is available to authorized users.

title: Increased Microerythrocyte Count in Homozygous α+-Thalassaemia Contributes to Protection against Severe Malarial Anaemia

text:
BACKGROUND The heritable haemoglobinopathy alpha(+)-thalassaemia is caused by the reduced synthesis of alpha-globin chains that form part of normal adult haemoglobin (Hb). Individuals homozygous for alpha(+)-thalassaemia have microcytosis and an increased erythrocyte count. Alpha(+)-thalassaemia homozygosity confers considerable protection against severe malaria, including severe malarial anaemia (SMA) (Hb concentration < 50 g/l), but does not influence parasite count. We tested the hypothesis that the erythrocyte indices associated with alpha(+)-thalassaemia homozygosity provide a haematological benefit during acute malaria.
 METHODS AND FINDINGS Data from children living on the north coast of Papua New Guinea who had participated in a case-control study of the protection afforded by alpha(+)-thalassaemia against severe malaria were reanalysed to assess the genotype-specific reduction in erythrocyte count and Hb levels associated with acute malarial disease. We observed a reduction in median erythrocyte count of approximately 1.5 x 10(12)/l in all children with acute falciparum malaria relative to values in community children (p < 0.001). We developed a simple mathematical model of the linear relationship between Hb concentration and erythrocyte count. This model predicted that children homozygous for alpha(+)-thalassaemia lose less Hb than children of normal genotype for a reduction in erythrocyte count of >1.1 x 10(12)/l as a result of the reduced mean cell Hb in homozygous alpha(+)-thalassaemia. In addition, children homozygous for alpha(+)-thalassaemia require a 10% greater reduction in erythrocyte count than children of normal genotype (p = 0.02) for Hb concentration to fall to 50 g/l, the cutoff for SMA. We estimated that the haematological profile in children homozygous for alpha(+)-thalassaemia reduces the risk of SMA during acute malaria compared to children of normal genotype (relative risk 0.52; 95% confidence interval [CI] 0.24-1.12, p = 0.09).
 CONCLUSIONS The increased erythrocyte count and microcytosis in children homozygous for alpha(+)-thalassaemia may contribute substantially to their protection against SMA. A lower concentration of Hb per erythrocyte and a larger population of erythrocytes may be a biologically advantageous strategy against the significant reduction in erythrocyte count that occurs during acute infection with the malaria parasite Plasmodium falciparum. This haematological profile may reduce the risk of anaemia by other Plasmodium species, as well as other causes of anaemia. Other host polymorphisms that induce an increased erythrocyte count and microcytosis may confer a similar advantage.

title: Ranking of elimination feasibility between malaria-endemic countries

text: Experience gained from the Global Malaria Eradication Program (1955-72) identified a set of shared technical and operational factors that enabled some countries to successfully eliminate malaria. Spatial data for these factors were assembled for all malaria-endemic countries and combined to provide an objective, relative ranking of countries by technical, operational, and combined elimination feasibility. The analysis was done separately for Plasmodium falciparum and Plasmodium vivax, and the limitations of the approach were discussed. The relative rankings suggested that malaria elimination would be most feasible in countries in the Americas and Asia, and least feasible in countries in central and west Africa. The results differed when feasibility was measured by technical or operational factors, highlighting the different types of challenge faced by each country. The results are not intended to be prescriptive, predictive, or to provide absolute assessments of feasibility, but they do show that spatial information is available to facilitate evidence-based assessments of the relative feasibility of malaria elimination by country that can be rapidly updated.

title: Sporadic Creutzfeldt-Jakob disease in the United Kingdom: analysis of epidemiological surveillance data for 1970-96.

text:
OBJECTIVE To identify changes in the occurrence of Creutzfeldt-Jakob disease that might be related to the epidemic of bovine spongiform encephalopathy.
 DESIGN Epidemiological surveillance of the United Kingdom population for Creutzfeldt-Jakob disease based on (a) referral of suspected cases by neurologists, neuropathologists, and neurophysiologists and (b) death certificates.
 SETTING England and Wales during 1970-84, and whole of the United Kingdom during 1985-96.    SUBJECTS All 662 patients identified as sporadic cases of Creutzfeldt-Jakob disease.
 MAIN OUTCOME MEASURES Age distribution of patients, age specific time trends of disease, occupational exposure to cattle, potential exposure to causative agent of bovine spongiform encephalopathy.
 RESULTS During 1970-96 there was an increase in the number of sporadic cases of Creutzfeldt-Jakob disease recorded yearly in England and Wales. The greatest increase was among people aged over 70. There was a statistically significant excess of cases among dairy farm workers and their spouses and among people at increased risk of contact with live cattle infected with bovine spongiform encephalopathy. During 1994-6 there were six deaths from sporadic Creutzfeldt-Jakob disease in the United Kingdom in patients aged under 30.
 CONCLUSIONS The increase in the incidence of sporadic Creutzfeldt-Jakob disease and the high incidence in dairy farmers in the United Kingdom may be unrelated to bovine spongiform encephalopathy. The most striking change in the pattern of Creutzfeldt-Jakob disease in the United Kingdom after the epidemic of bovine spongiform encephalopathy is provided by the incidence in a group of exceptionally young patients with a consistent and unusual neuropathological profile. The outcome of mouse transmission studies and the future incidence of the disease in the United Kingdom and elsewhere, will be important in judging whether the agent causing bovine spongiform encephalopathy has infected humans.

title: Transmission of sporadic Creutzfeldt-Jakob disease by blood transfusion: risk factor or possible biases.

text:
BACKGROUND The occurrence of transfusion transmissions of variant Creutzfeldt-Jakob disease (CJD) cases has reawakened attention to the possible similar risk posed by other forms of CJD.    STUDY DESIGN AND METHODS CJD with a definite or probable diagnosis (sporadic CJD, n = 741; genetic CJD, n = 175) and no-CJD patients with definite alternative diagnosis (n = 482) with available blood transfusion history were included in the study. The risk of exposure to blood transfusion occurring more than 10 years before disease onset and for some possible confounding factors was evaluated by calculating crude odds ratios (ORs). Variables with significant ORs in univariate analyses were included in multivariate logistic regression analyses.
 RESULTS In the univariate model, blood transfusion occurring more than 10 years before clinical onset is 4.1-fold more frequent in sporadic CJD than in other neurologic disorders. This significance is lost when the 10-year lag time was not considered. Multivariate analyses show that the risk of developing sporadic CJD after transfusion increases (OR, 5.05) after adjusting for possible confounding factors. Analysis conducted on patients with genetic CJD did not reveal any significant risk factor associated with transfusion.
 CONCLUSION This is the first case-control study showing a significant risk of transfusion occurring more than 10 years before clinical onset in sporadic CJD patients. It remains questionable whether the significance of these data is biologically plausible or the consequence of biases in the design of the study, but they counterbalance previous epidemiologic negative reports that might have overestimated the assessment of blood safety in sporadic CJD.

title: Imported malaria in children: a national surveillance in the Netherlands and a review of European studies.

text:
BACKGROUND Falciparum malaria or malaria tropica is one of the leading causes of childhood mortality worldwide. Malaria-related deaths occur mainly in sub-Saharan Africa, where an estimated 365 million clinical cases of Plasmodium falciparum malaria occur each year. In Europe, imported malaria cases occur due to returning travellers or immigration mostly from African countries. Children are more at risk than adults. The objective of this study was to identify high risk groups for imported childhood malaria in Europe in order to guide development of strategies for prevention, early recognition and management.
 METHODS In the period May 2003-January 2005 we reviewed all cases of paediatric malaria in the Netherlands notified by the Dutch Paediatric Surveillance System (Nederland Signalerings Centrum Kindergeneeskunde, NSCK) and the literature on imported malaria in children in Europe published between 1996 and 2006.
 RESULTS Malaria occurred mainly in children of long-term (n = 15, 47%) and new (n = 8, 25%) immigrants and was mostly acquired in sub-Saharan Africa. The dominant species was P. falciparum. Only one quarter of children had used adequate malaria chemoprophylaxis. Complicated disease occurred in 10 (31%) of cases. We also reviewed the literature and found 6082 reported cases of imported malaria among children in Europe; among these, four died and only one was reported to develop neurological sequelae.
 CONCLUSION Imported malaria in children remains an important problem and is unlikely to decrease unless the reasons for inadequate prophylaxis are addressed.

title: Quality Testing of Artemisinin-Based Antimalarial Drugs in Myanmar.

text: Artemisinin-based combination therapies are the frontline treatment of Plasmodium falciparum malaria. The circulation of falsified and substandard artemisinin-based antimalarials in Southeast Asia has been a major predicament for the malaria elimination campaign. To provide an update of this situation, we purchased 153 artemisinin-containing antimalarials, as convenience samples, in private drug stores from different regions of Myanmar. The quality of these drugs in terms of their artemisinin derivative content was tested using specific dipsticks for these artemisinin derivatives, as point-of-care devices. A subset of these samples was further tested by high-performance liquid chromatography (HPLC). This survey identified that > 35% of the collected drugs were oral artesunate and artemether monotherapies. When tested with the dipsticks, all but one sample passed the assays, indicating that the detected artemisinin derivative content corresponded approximately to the labeled contents. However, one artesunate injection sample was found to contain no active ingredient at all by the dipstick assay and subsequent HPLC analysis. The continued circulation of oral monotherapies and the description, for the first time, of falsified parenteral artesunate provides a worrisome picture of the antimalarial drug quality in Myanmar during the malaria elimination phase, a situation that deserves more oversight from regulatory authorities.

title: Modelling the Impact of Artemisinin Combination Therapy and Long-Acting Treatments on Malaria Transmission Intensity

text:
BACKGROUND Artemisinin derivatives used in recently introduced combination therapies (ACTs) for Plasmodium falciparum malaria significantly lower patient infectiousness and have the potential to reduce population-level transmission of the parasite. With the increased interest in malaria elimination, understanding the impact on transmission of ACT and other antimalarial drugs with different pharmacodynamics becomes a key issue. This study estimates the reduction in transmission that may be achieved by introducing different types of treatment for symptomatic P. falciparum malaria in endemic areas.
 METHODS AND FINDINGS We developed a mathematical model to predict the potential impact on transmission outcomes of introducing ACT as first-line treatment for uncomplicated malaria in six areas of varying transmission intensity in Tanzania. We also estimated the impact that could be achieved by antimalarials with different efficacy, prophylactic time, and gametocytocidal effects. Rates of treatment, asymptomatic infection, and symptomatic infection in the six study areas were estimated using the model together with data from a cross-sectional survey of 5,667 individuals conducted prior to policy change from sulfadoxine-pyrimethamine to ACT. The effects of ACT and other drug types on gametocytaemia and infectiousness to mosquitoes were independently estimated from clinical trial data. Predicted percentage reductions in prevalence of infection and incidence of clinical episodes achieved by ACT were highest in the areas with low initial transmission. A 53% reduction in prevalence of infection was seen if 100% of current treatment was switched to ACT in the area where baseline slide-prevalence of parasitaemia was lowest (3.7%), compared to an 11% reduction in the highest-transmission setting (baseline slide prevalence = 57.1%). Estimated percentage reductions in incidence of clinical episodes were similar. The absolute size of the public health impact, however, was greater in the highest-transmission area, with 54 clinical episodes per 100 persons per year averted compared to five per 100 persons per year in the lowest-transmission area. High coverage was important. Reducing presumptive treatment through improved diagnosis substantially reduced the number of treatment courses required per clinical episode averted in the lower-transmission settings although there was some loss of overall impact on transmission. An efficacious antimalarial regimen with no specific gametocytocidal properties but a long prophylactic time was estimated to be more effective at reducing transmission than a short-acting ACT in the highest-transmission setting.
 CONCLUSIONS Our results suggest that ACTs have the potential for transmission reductions approaching those achieved by insecticide-treated nets in lower-transmission settings. ACT partner drugs and nonartemisinin regimens with longer prophylactic times could result in a larger impact in higher-transmission settings, although their long term benefit must be evaluated in relation to the risk of development of parasite resistance.