We need to combine generalist and specialist skills
CONSERVATION Keep cruise ships off remote reef in South Pacific rich in species p.372 PUBLISHING Use ORCID and DOIs more for frictionless communication p.372 HISTORY Maria Mitchell, pioneering astronomer and pithy pedagogue p.370 POLICY Conservation tries a new way to catalogue and synthesize research p.364 Four principles for synthesizing evidence Reward the creation of analyses for policymakers that are inclusive, rigorous, transparent and accessible, urge Christl A. Donnelly and colleagues. To improve vaccine uptake, nations can build on others' experience-if research is synthesized regularly and well.
The introduction of artemisinin-based combination therapy in sub-Saharan Africa has prompted calls for increased use of parasitologic diagnosis for malaria. We evaluated the cost-effectiveness of rapid diagnostic tests (RDTs) in comparison to microscopy in guiding treatment of non-severe febrile illness at varying levels of malaria endemicity using data on test accuracy and costs collected as part of a Tanzanian trial. If prescribers complied with current guidelines, microscopy would give rise to lower average costs per patient correctly treated than RDTs in areas of both high and low transmission. RDT introduction would result in an additional 2.3% and 9.4% of patients correctly treated, at an incremental cost of $25 and $7 in the low and high transmission settings, respectively. Cost-effectiveness would be worse if prescribers do not comply with test results. The cost of this additional benefit may be higher than many countries can afford without external assistance or lower RDT prices.
Objectives To examine the impact of use of rapid diagnostic tests for malaria on prescribing of antimicrobials, specifically antibiotics, for acute febrile illness in Africa and Asia.Design Analysisof nine preselected linked and codesigned observational and randomised studies (eight cluster or individually randomised trials and one observational study).Setting Public and private healthcare settings, 2007-13, in Afghanistan, Cameroon, Ghana, Nigeria, Tanzania, and Uganda.Participants 522 480 children and adults with acute febrile illness.Interventions Rapid diagnostic tests for malaria.Main outcome measures Proportions of patients for whom an antibiotic was prescribed in trial groups who had undergone rapid diagnostic testing compared with controls and in patients with negative test results compared with patients with positive results. A secondary aim compared classes of antibiotics prescribed in different settings.Results Antibiotics were prescribed to 127 052/238 797 (53%) patients in control groups and 167 714/283 683 (59%) patients in intervention groups. Antibiotics were prescribed to 40% (35 505/89 719) of patients with a positive test result for malaria and to 69% (39 400/57 080) of those with a negative result. All but one study showed a trend toward more antibiotic prescribing in groups who underwent rapid diagnostic tests. Random effects meta-analysis of the trials showed that the overall risk of antibiotic prescription was 21% higher (95% confidence interval 7% to 36%) in intervention settings. In most intervention settings, patients with negative test results received more antibiotic prescriptions than patients with positive results for all the most commonly used classes: penicillins, trimethoprim-sulfamethoxazole (one exception), tetracyclines, and metronidazole.Conclusions Introduction of rapid diagnostic tests for malaria to reduce unnecessary use of antimalarials—a beneficial public health outcome—could drive up untargeted use of antibiotics. That 69% of patients were prescribed antibiotics when test results were negative probably represents overprescription.This included antibiotics from several classes, including those like metronidazole that are seldom appropriate for febrile illness, across varied clinical, health system, and epidemiological settings. It is often assumed that better disease specific diagnostics will reduce antimicrobial overuse, but they might simply shift it from one antimicrobial class to another. Current global implementation of malaria testing might increase untargeted antibiotic use and must be examined.
We assessed the abundance of dopamine transporter messenger RNA (DAT mRNA) in various human midbrain dopamine cell groups using in situ hybridization. The youngest individuals studied (17-23 years of age) exhibited significant regional heterogeneity of DAT expression, both in terms of the number of dopamine neurons expressing DAT mRNA and the abundance of DAT mRNA per cell, with the highest levels of expression evident within the ventral tier of the substantia nigra and lowest expression within the retrorubral field. In the older subjects (65-72 years old) analyzed, DAT mRNA in all regions was reduced to the level seen in the retrorubal field, indicating a positive correlation between initial levels of DAT expression and subsequent age-related reductions, with some regions exhibiting up to a 75% loss of DAT mRNA with age. The age-related decline in DAT mRNA was due to both a decrease in the abundance of DAT mRNA per dopamine cell as well as a decrease in the total number of dopamine cells expressing DAT mRNA, although tyrosine hydroxylase expression was less affected. These results indicate that changes in dopamine neurotransmission seen in normal aging may be related to altered DAT gene expression.
BackgroundMany patients with malaria-like symptoms seek treatment in private medicine retail outlets (PMR) that distribute malaria medicines but do not traditionally provide diagnostic services, potentially leading to overtreatment with antimalarial drugs. To achieve universal access to prompt parasite-based diagnosis, many malaria-endemic countries are considering scaling up malaria rapid diagnostic tests (RDTs) in these outlets, an intervention that may require legislative changes and major investments in supporting programs and infrastructures. This review identifies studies that introduced malaria RDTs in PMRs and examines study outcomes and success factors to inform scale up decisions.MethodsPublished and unpublished studies that introduced malaria RDTs in PMRs were systematically identified and reviewed. Literature published before November 2016 was searched in six electronic databases, and unpublished studies were identified through personal contacts and stakeholder meetings. Outcomes were extracted from publications or provided by principal investigators.ResultsSix published and six unpublished studies were found. Most studies took place in sub-Saharan Africa and were small-scale pilots of RDT introduction in drug shops or pharmacies. None of the studies assessed large-scale implementation in PMRs. RDT uptake varied widely from 8%-100%. Provision of artemisinin-based combination therapy (ACT) for patients testing positive ranged from 30%-99%, and was more than 85% in five studies. Of those testing negative, provision of antimalarials varied from 2%-83% and was less than 20% in eight studies. Longer provider training, lower RDT retail prices and frequent supervision appeared to have a positive effect on RDT uptake and provider adherence to test results. Performance of RDTs by PMR vendors was generally good, but disposal of medical waste and referral of patients to public facilities were common challenges.ConclusionsExpanding services of PMRs to include malaria diagnostic services may hold great promise to improve malaria case management and curb overtreatment with antimalarials. However, doing so will require careful planning, investment and additional research to develop and sustain effective training, supervision, waste-management, referral and surveillance programs beyond the public sector.
Chronic exposure to cocaine induces long-term adaptations that are likely to involve changes in transcription factor expression. This possibility has not been examined in the cocaine-exposed human brain. The transcription factor nurr1 is highly expressed in rodent midbrain dopamine neurons and is essential for their proper phenotypic development. Here we show that human NURR1 gene expression is robust within control subjects and reduced markedly within the dopamine neurons of human cocaine abusers. NURR1 is known to regulate transcription of the gene encoding the cocainesensitive dopamine transporter (DAT). We show here that DAT gene expression also is reduced markedly in the dopamine neurons of NURR1-deficient cocaine abusers, suggesting that NURR1 plays a critical role in vivo in controlling human DAT gene expression and adaptation to repeated exposure to cocaine.
The molecular characteristics of midbrain dopamine (DA) neurons have been extensively studied in Parkinson's disease (PD). No such studies of the characteristics of midbrain DA neurons in Alzheimer's disease (AD) or Alzheimer's disease with parkinsonism (AD/Park) have been published. We examined the levels of tyrosine hydroxylase (TH) protein, and the expression of TH and dopamine transporter (DAT) mRNAs, in midbrain neurons of PD, AD, and AD/Park cases. In PD, the loss of TH protein in the ventral tier of the substantia nigra pars compacta (SNpc) of the PD group in accompanied by severe losses in the number of neurons that express TH mRNA and DAT mRNA (74% loss). Remaining neurons show a shift to higher concentrations of TH mRNA but a shift to lower concentrations of DAT mRNA per cell. Hence, there is evidence that compensation in the remaining neurons can elevate concentrations of TH mRNA and lower DAT mRNA. Alternatively, there may be a predilection for a loss of neurons with high levels of DAT mRNA and low TH mRNA levels within the SNpc of PD cases. There was no change in TH protein but an elevation of TH mRNA concentrations per neuron without any change in concentrations of DAT mRNA in the AD group. The AD/Park group did not exhibit changes in the level of TH protein, but showed a small loss (26%) of neurons in the SNpc and a greater loss in other regions of the midbrain (43-53%). Remaining DA neurons showed a marked shift to lower concentrations of DAT mRNA per neuron and a nonsignificant shift in cellular concentration of TH mRNA to higher levels. This is consistent with our previous work showing that with AD/Park there is a significant reduction in the number of DAT sites located on DA terminals in the striatum, but the midbrain neurons have not died. Our results indicate that the differential regulation of mRNAs encoding TH and DAT is similar in the parkinsonian disorders (PD and AD/Park) even though the degree of cell death is very different. This might suggest that compensatory events occur in these DA neurons in AD/Park that are similar to those in PD and that result in differential effects on mRNAs encoding TH and DAT proteins.
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