Exposure of Escherichia coli to antibiotic-efflux pump inhibitor combinations in a pharmacokinetic model: impact on bacterial clearance and drug resistance

BACKGROUND

Efflux pump inhibitors (EPIs) offer an attractive therapeutic option when combined with existing classes. However, their optimal dosing strategies are unknown.

METHODS

MICs of ciprofloxacin (CIP)+/-chlorpromazine, phenylalanine-arginine β naphthylamide (PAβN) and a developmental molecule MBX-4191 were determined and the pharmacodynamics (PD) was studied in an in vitro model employing Escherichia coli MG1655 and its isogenic MarR mutant (I1147). Exposure ranging experiments were performed initially then fractionation. Changes in bacterial load and population profiles were assessed. Strains recovered after EPI simulations were studied by WGS.

RESULTS

The CIPMICs for E. coli MG1655 and I1147 were 0.08 and 0.03 mg/L. Chlorpromazine at a concentration of 60 mg/L, PAβN concentrations of 30 mg/L and MBX-4191 concentrations of 0.5-1.0 mg/L reduced CIP MICs for I1147 and enhanced bacterial killing. Using CIP at an AUC of 1.2 mg·h/L, chlorpromazine AUC was best related to reduction in bacterial load at 24 h, however, when the time drug concentration was greater than 25 mg/L (T > 25 mg/L) chlorpromazine was also strongly related to the effect. For PaβN with CIP AUC, 0.6 mg·h/L PaβN AUC was best related to a reduction in bacterial load. MBX-4191T > 0.5-0.75 mg·h/L was best related to reduction in bacterial load. Changes in population profiles were not seen in experiments of ciprofloxacin + EPIs. WGS of recovered strains from simulations with all three EPIs showed mutations in gyrA, gyrB or marR.

CONCLUSIONS

AUC was the pharmacodynamic driver for chlorpromazine and PAβN while T > threshold was the driver for MBX-4191 and important in the activity of chlorpromazine and PAβN. Changes in population profiles did not occur with combinations of ciprofloxacin + EPIs, however, mutations in gyrA, gyrB and marR were detected.

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks.

Thermal neutron transmutation doping of GaN semiconductors

High quality Ge doping of GaN is demonstrated using primarily thermal neutrons for the first time. In this study, GaN was doped with Ge to concentrations from 10¹⁶ Ge atoms/cm³ to 10¹⁸ Ge atoms/cm³. The doping concentrations were measured using gamma-ray spectroscopy and confirmed using SIMS analysis. The data from SIMS analysis also show consistent Ge doping concentration throughout the depth of the GaN wafers. After irradiation, the GaN was annealed in a nitrogen environment at 950 °C for 30 min. The neutron doping process turns out to produce spatially uniform doping throughout the whole volume of the GaN substrate.

Qualitative Ampule and Multitest for Beta-Lactam Residues in Fluid Milk Products: Collaborative Study

A collaborative study was performed on a rapid Bacillus stearothermophilus agar diffusion ampule method to detect low levels of penicillin G in 7 types of fluid milk products. A multitest technique for processing a large number of samples simultaneously was also studied. Slight modifications were made in the original method to establish more uniformity and to eliminate doubtful responses by specifying a confirmation procedure. Twenty samples spiked with penicillin G (0.000 to 0.008 IU/mL) and tetracycline hydrochloride were frozen and sent to 20 laboratories in the ampule test, and 16 laboratories in the multitest. Each analyst was asked to do a screening run and a confirmation run. Results were reported by color reaction and also as positive or negative for β-lactam inhibitors. The concentrations (penicillin G) where percent positive results equal 100 or not significantly less than 100 (α = 0.05) ranged from 0.005 to 0.007 IU/mi in the ampule test and from 0.004 to 0.007 IU/mL in the multitest. Both techniques have been adopted official first action.

An emerging framework for fully incorporating public involvement (PI) into patient-reported outcome measures (PROMs)

Patient-reported outcome measures (PROMs) are widely used in the United Kingdom (UK) and internationally to report and monitor patients’ subjective assessments of their symptoms and functional status and also their quality of life. Whilst the importance of involving the public in PROM development to increase the quality of the developed PROM has been highlighted this practice is not widespread. There is a lack of guidance on how public involvement (PI) could be embedded in the development of PROMs, where the roles can be more complex than in other types of research. This paper provides a timely review and sets out an emerging framework for fully incorporating PI into PROM development.

The burden of child and maternal malnutrition and trends in its indicators in the states of India: the Global Burden of Disease Study 1990-2017

BACKGROUND

Malnutrition is a major contributor to disease burden in India. To inform subnational action, we aimed to assess the disease burden due to malnutrition and the trends in its indicators in every state of India in relation to Indian and global nutrition targets.

METHODS

We analysed the disease burden attributable to child and maternal malnutrition, and the trends in the malnutrition indicators from 1990 to 2017 in every state of India using all accessible data from multiple sources, as part of Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017. The states were categorised into three groups using their Socio-demographic Index (SDI) calculated by GBD on the basis of per capita income, mean education, and fertility rate in women younger than 25 years. We projected the prevalence of malnutrition indicators for the states of India up to 2030 on the basis of the 1990-2017 trends for comparison with India National Nutrition Mission (NNM) 2022 and WHO and UNICEF 2030 targets.

FINDINGS

Malnutrition was the predominant risk factor for death in children younger than 5 years of age in every state of India in 2017, accounting for 68·2% (95% UI 65·8-70·7) of the total under-5 deaths, and the leading risk factor for health loss for all ages, responsible for 17·3% (16·3-18·2) of the total disability-adjusted life years (DALYs). The malnutrition DALY rate was much higher in the low SDI than in the middle SDI and high SDI state groups. This rate varied 6·8 times between the states in 2017, and was highest in the states of Uttar Pradesh, Bihar, Assam, and Rajasthan. The prevalence of low birthweight in India in 2017 was 21·4% (20·8-21·9), child stunting 39·3% (38·7-40·1), child wasting 15·7% (15·6-15·9), child underweight 32·7% (32·3-33·1), anaemia in children 59·7% (56·2-63·8), anaemia in women 15-49 years of age 54·4% (53·7-55·2), exclusive breastfeeding 53·3% (51·5-54·9), and child overweight 11·5% (8·5-14·9). If the trends estimated up to 2017 for the indicators in the NNM 2022 continue in India, there would be 8·9% excess prevalence for low birthweight, 9·6% for stunting, 4·8% for underweight, 11·7% for anaemia in children, and 13·8% for anaemia in women relative to the 2022 targets. For the additional indicators in the WHO and UNICEF 2030 targets, the trends up to 2017 would lead to 10·4% excess prevalence for wasting, 14·5% excess prevalence for overweight, and 10·7% less exclusive breastfeeding in 2030. The prevalence of malnutrition indicators, their rates of improvement, and the gaps between projected prevalence and targets vary substantially between the states.

INTERPRETATION

Malnutrition continues to be the leading risk factor for disease burden in India. It is encouraging that India has set ambitious targets to reduce malnutrition through NNM. The trends up to 2017 indicate that substantially higher rates of improvement will be needed for all malnutrition indicators in most states to achieve the Indian 2022 and the global 2030 targets. The state-specific findings in this report indicate the effort needed in each state, which will be useful in tracking and motivating further progress. Similar subnational analyses might be useful for other low-income and middle-income countries.

FUNDING

Bill & Melinda Gates Foundation; Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, Government of India.

Mapping the global prevalence, incidence, and mortality of Plasmodium falciparum, 2000-17: a spatial and temporal modelling study

BACKGROUND

Since 2000, the scale-up of malaria control interventions has substantially reduced morbidity and mortality caused by the disease globally, fuelling bold aims for disease elimination. In tandem with increased availability of geospatially resolved data, malaria control programmes increasingly use high-resolution maps to characterise spatially heterogeneous patterns of disease risk and thus efficiently target areas of high burden.

METHODS

We updated and refined the Plasmodium falciparum parasite rate and clinical incidence models for sub-Saharan Africa, which rely on cross-sectional survey data for parasite rate and intervention coverage. For malaria endemic countries outside of sub-Saharan Africa, we produced estimates of parasite rate and incidence by applying an ecological downscaling approach to malaria incidence data acquired via routine surveillance. Mortality estimates were derived by linking incidence to systematically derived vital registration and verbal autopsy data. Informed by high-resolution covariate surfaces, we estimated P falciparum parasite rate, clinical incidence, and mortality at national, subnational, and 5 × 5 km pixel scales with corresponding uncertainty metrics.

FINDINGS

We present the first global, high-resolution map of P falciparum malaria mortality and the first global prevalence and incidence maps since 2010. These results are combined with those for Plasmodium vivax (published separately) to form the malaria estimates for the Global Burden of Disease 2017 study. The P falciparum estimates span the period 2000-17, and illustrate the rapid decline in burden between 2005 and 2017, with incidence declining by 27·9% and mortality declining by 42·5%. Despite a growing population in endemic regions, P falciparum cases declined between 2005 and 2017, from 232·3 million (95% uncertainty interval 198·8-277·7) to 193·9 million (156·6-240·2) and deaths declined from 925 800 (596 900-1 341 100) to 618 700 (368 600-952 200). Despite the declines in burden, 90·1% of people within sub-Saharan Africa continue to reside in endemic areas, and this region accounted for 79·4% of cases and 87·6% of deaths in 2017.

INTERPRETATION

High-resolution maps of P falciparum provide a contemporary resource for informing global policy and malaria control planning, programme implementation, and monitoring initiatives. Amid progress in reducing global malaria burden, areas where incidence trends have plateaued or increased in the past 5 years underscore the fragility of hard-won gains against malaria. Efforts towards elimination should be strengthened in such areas, and those where burden remained high throughout the study period.

FUNDING

Bill & Melinda Gates Foundation.

The global burden of tuberculosis: results from the Global Burden of Disease Study 2015

BACKGROUND

An understanding of the trends in tuberculosis incidence, prevalence, and mortality is crucial to tracking of the success of tuberculosis control programmes and identification of remaining challenges. We assessed trends in the fatal and non-fatal burden of tuberculosis over the past 25 years for 195 countries and territories.

METHODS

We analysed 10 691 site-years of vital registration data, 768 site-years of verbal autopsy data, and 361 site-years of mortality surveillance data using the Cause of Death Ensemble model to estimate tuberculosis mortality rates. We analysed all available age-specific and sex-specific data sources, including annual case notifications, prevalence surveys, and estimated cause-specific mortality, to generate internally consistent estimates of incidence, prevalence, and mortality using DisMod-MR 2.1, a Bayesian meta-regression tool. We assessed how observed tuberculosis incidence, prevalence, and mortality differed from expected trends as predicted by the Socio-demographic Index (SDI), a composite indicator based on income per capita, average years of schooling, and total fertility rate. We also estimated tuberculosis mortality and disability-adjusted life-years attributable to the independent effects of risk factors including smoking, alcohol use, and diabetes.

FINDINGS

Globally, in 2015, the number of tuberculosis incident cases (including new and relapse cases) was 10·2 million (95% uncertainty interval 9·2 million to 11·5 million), the number of prevalent cases was 10·1 million (9·2 million to 11·1 million), and the number of deaths was 1·3 million (1·1 million to 1·6 million). Among individuals who were HIV negative, the number of incident cases was 8·8 million (8·0 million to 9·9 million), the number of prevalent cases was 8·9 million (8·1 million to 9·7 million), and the number of deaths was 1·1 million (0·9 million to 1·4 million). Annualised rates of change from 2005 to 2015 showed a faster decline in mortality (-4·1% [-5·0 to -3·4]) than in incidence (-1·6% [-1·9 to -1·2]) and prevalence (-0·7% [-1·0 to -0·5]) among HIV-negative individuals. The SDI was inversely associated with HIV-negative mortality rates but did not show a clear gradient for incidence and prevalence. Most of Asia, eastern Europe, and sub-Saharan Africa had higher rates of HIV-negative tuberculosis burden than expected given their SDI. Alcohol use accounted for 11·4% (9·3-13·0) of global tuberculosis deaths among HIV-negative individuals in 2015, diabetes accounted for 10·6% (6·8-14·8), and smoking accounted for 7·8% (3·8-12·0).

INTERPRETATION

Despite a concerted global effort to reduce the burden of tuberculosis, it still causes a large disease burden globally. Strengthening of health systems for early detection of tuberculosis and improvement of the quality of tuberculosis care, including prompt and accurate diagnosis, early initiation of treatment, and regular follow-up, are priorities. Countries with higher than expected tuberculosis rates for their level of sociodemographic development should investigate the reasons for lagging behind and take remedial action. Efforts to prevent smoking, alcohol use, and diabetes could also substantially reduce the burden of tuberculosis.

FUNDING

Bill & Melinda Gates Foundation.

GRIPP2 reporting checklists: tools to improve reporting of patient and public involvement in research

BACKGROUND

While the patient and public involvement (PPI) evidence base has expanded over the past decade, the quality of reporting within papers is often inconsistent, limiting our understanding of how it works, in what context, for whom, and why.

OBJECTIVE

To develop international consensus on the key items to report to enhance the quality, transparency, and consistency of the PPI evidence base. To collaboratively involve patients as research partners at all stages in the development of GRIPP2.

METHODS

The EQUATOR method for developing reporting guidelines was used. The original GRIPP (Guidance for Reporting Involvement of Patients and the Public) checklist was revised, based on updated systematic review evidence. A three round Delphi survey was used to develop consensus on items to be included in the guideline. A subsequent face-to-face meeting produced agreement on items not reaching consensus during the Delphi process.

RESULTS

One hundred forty-three participants agreed to participate in round one, with an 86% (123/143) response for round two and a 78% (112/143) response for round three. The Delphi survey identified the need for long form (LF) and short form (SF) versions. GRIPP2-LF includes 34 items on aims, definitions, concepts and theory, methods, stages and nature of involvement, context, capture or measurement of impact, outcomes, economic assessment, and reflections and is suitable for studies where the main focus is PPI. GRIPP2-SF includes five items on aims, methods, results, outcomes, and critical perspective and is suitable for studies where PPI is a secondary focus.

CONCLUSIONS

GRIPP2-LF and GRIPP2-SF represent the first international evidence based, consensus informed guidance for reporting patient and public involvement in research. Both versions of GRIPP2 aim to improve the quality, transparency, and consistency of the international PPI evidence base, to ensure PPI practice is based on the best evidence. In order to encourage its wide dissemination this article is freely accessible on The BMJ and Research Involvement and Engagement journal websites.

GRIPP2 reporting checklists: tools to improve reporting of patient and public involvement in research

Background While the patient and public involvement (PPI) evidence base has expanded over the past decade, the quality of reporting within papers is often inconsistent, limiting our understanding of how it works, in what context, for whom, and why.Objective To develop international consensus on the key items to report to enhance the quality, transparency, and consistency of the PPI evidence base. To collaboratively involve patients as research partners at all stages in the development of GRIPP2.Methods The EQUATOR method for developing reporting guidelines was used. The original GRIPP (Guidance for Reporting Involvement of Patients and the Public) checklist was revised, based on updated systematic review evidence. A three round Delphi survey was used to develop consensus on items to be included in the guideline. A subsequent face-to-face meeting produced agreement on items not reaching consensus during the Delphi process.Results 143 participants agreed to participate in round one, with an 86% (123/143) response for round two and a 78% (112/143) response for round three. The Delphi survey identified the need for long form (LF) and short form (SF) versions. GRIPP2-LF includes 34 items on aims, definitions, concepts and theory, methods, stages and nature of involvement, context, capture or measurement of impact, outcomes, economic assessment, and reflections and is suitable for studies where the main focus is PPI. GRIPP2-SF includes five items on aims, methods, results, outcomes, and critical perspective and is suitable for studies where PPI is a secondary focus.Conclusions GRIPP2-LF and GRIPP2-SF represent the first international evidence based, consensus informed guidance for reporting patient and public involvement in research. Both versions of GRIPP2 aim to improve the quality, transparency, and consistency of the international PPI evidence base, to ensure PPI practice is based on the best evidence. In order to encourage its wide dissemination this article is freely accessible on The BMJ and Research Involvement and Engagement journal websites.

Measuring the health-related Sustainable Development Goals in 188 countries: a baseline analysis from the Global Burden of Disease Study 2015

BACKGROUND

In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030. We provide an analysis of 33 health-related SDG indicators based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015).

METHODS

We applied statistical methods to systematically compiled data to estimate the performance of 33 health-related SDG indicators for 188 countries from 1990 to 2015. We rescaled each indicator on a scale from 0 (worst observed value between 1990 and 2015) to 100 (best observed). Indices representing all 33 health-related SDG indicators (health-related SDG index), health-related SDG indicators included in the Millennium Development Goals (MDG index), and health-related indicators not included in the MDGs (non-MDG index) were computed as the geometric mean of the rescaled indicators by SDG target. We used spline regressions to examine the relations between the Socio-demographic Index (SDI, a summary measure based on average income per person, educational attainment, and total fertility rate) and each of the health-related SDG indicators and indices.

FINDINGS

In 2015, the median health-related SDG index was 59·3 (95% uncertainty interval 56·8-61·8) and varied widely by country, ranging from 85·5 (84·2-86·5) in Iceland to 20·4 (15·4-24·9) in Central African Republic. SDI was a good predictor of the health-related SDG index (r2=0·88) and the MDG index (r2=0·92), whereas the non-MDG index had a weaker relation with SDI (r2=0·79). Between 2000 and 2015, the health-related SDG index improved by a median of 7·9 (IQR 5·0-10·4), and gains on the MDG index (a median change of 10·0 [6·7-13·1]) exceeded that of the non-MDG index (a median change of 5·5 [2·1-8·9]). Since 2000, pronounced progress occurred for indicators such as met need with modern contraception, under-5 mortality, and neonatal mortality, as well as the indicator for universal health coverage tracer interventions. Moderate improvements were found for indicators such as HIV and tuberculosis incidence, minimal changes for hepatitis B incidence took place, and childhood overweight considerably worsened.

INTERPRETATION

GBD provides an independent, comparable avenue for monitoring progress towards the health-related SDGs. Our analysis not only highlights the importance of income, education, and fertility as drivers of health improvement but also emphasises that investments in these areas alone will not be sufficient. Although considerable progress on the health-related MDG indicators has been made, these gains will need to be sustained and, in many cases, accelerated to achieve the ambitious SDG targets. The minimal improvement in or worsening of health-related indicators beyond the MDGs highlight the need for additional resources to effectively address the expanded scope of the health-related SDGs.

FUNDING

Bill & Melinda Gates Foundation.

Leaf venation, as a resistor, to optimize a switchable IR absorber

Leaf vascular patterns are the mechanisms and mechanical support for the transportation of fluidics for photosynthesis and leaf development properties. Vascular hierarchical networks in leaves have far-reaching functions in optimal transport efficiency of functional fluidics. Embedding leaf morphogenesis as a resistor network is significant in the optimization of a translucent thermally functional material. This will enable regulation through pressure equalization by diminishing flow pressure variation. This paper investigates nature's vasculature networks that exhibit hierarchical branching scaling applied to microfluidics. To enable optimum potential for pressure drop regulation by algorithm design. This code analysis of circuit conduit optimization for transport fluidic flow resistance is validated against CFD simulation, within a closed loop network. The paper will propose this self-optimization, characterization by resistance seeking targeting to determine a microfluidic network as a resistor. To advance a thermally function material as a switchable IR absorber.

Demographic and epidemiologic drivers of global cardiovascular mortality

BACKGROUND

Global deaths from cardiovascular disease are increasing as a result of population growth, the aging of populations, and epidemiologic changes in disease. Disentangling the effects of these three drivers on trends in mortality is important for planning the future of the health care system and benchmarking progress toward the reduction of cardiovascular disease.

METHODS

We used mortality data from the Global Burden of Disease Study 2013, which includes data on 188 countries grouped into 21 world regions. We developed three counterfactual scenarios to represent the principal drivers of change in cardiovascular deaths (population growth alone, population growth and aging, and epidemiologic changes in disease) from 1990 to 2013. Secular trends and correlations with changes in national income were examined.

RESULTS

Global deaths from cardiovascular disease increased by 41% between 1990 and 2013 despite a 39% decrease in age-specific death rates; this increase was driven by a 55% increase in mortality due to the aging of populations and a 25% increase due to population growth. The relative contributions of these drivers varied by region; only in Central Europe and Western Europe did the annual number of deaths from cardiovascular disease actually decline. Change in gross domestic product per capita was correlated with change in age-specific death rates only among upper-middle income countries, and this correlation was weak; there was no significant correlation elsewhere.

CONCLUSIONS

The aging and growth of the population resulted in an increase in global cardiovascular deaths between 1990 and 2013, despite a decrease in age-specific death rates in most regions. Only Central and Western Europe had gains in cardiovascular health that were sufficient to offset these demographic forces. (Funded by the Bill and Melinda Gates Foundation and others.).

Global, regional, and national levels and causes of maternal mortality during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

The fifth Millennium Development Goal (MDG 5) established the goal of a 75% reduction in the maternal mortality ratio (MMR; number of maternal deaths per 100,000 livebirths) between 1990 and 2015. We aimed to measure levels and track trends in maternal mortality, the key causes contributing to maternal death, and timing of maternal death with respect to delivery.

METHODS

We used robust statistical methods including the Cause of Death Ensemble model (CODEm) to analyse a database of data for 7065 site-years and estimate the number of maternal deaths from all causes in 188 countries between 1990 and 2013. We estimated the number of pregnancy-related deaths caused by HIV on the basis of a systematic review of the relative risk of dying during pregnancy for HIV-positive women compared with HIV-negative women. We also estimated the fraction of these deaths aggravated by pregnancy on the basis of a systematic review. To estimate the numbers of maternal deaths due to nine different causes, we identified 61 sources from a systematic review and 943 site-years of vital registration data. We also did a systematic review of reports about the timing of maternal death, identifying 142 sources to use in our analysis. We developed estimates for each country for 1990-2013 using Bayesian meta-regression. We estimated 95% uncertainty intervals (UIs) for all values.

FINDINGS

292,982 (95% UI 261,017-327,792) maternal deaths occurred in 2013, compared with 376,034 (343,483-407,574) in 1990. The global annual rate of change in the MMR was -0·3% (-1·1 to 0·6) from 1990 to 2003, and -2·7% (-3·9 to -1·5) from 2003 to 2013, with evidence of continued acceleration. MMRs reduced consistently in south, east, and southeast Asia between 1990 and 2013, but maternal deaths increased in much of sub-Saharan Africa during the 1990s. 2070 (1290-2866) maternal deaths were related to HIV in 2013, 0·4% (0·2-0·6) of the global total. MMR was highest in the oldest age groups in both 1990 and 2013. In 2013, most deaths occurred intrapartum or postpartum. Causes varied by region and between 1990 and 2013. We recorded substantial variation in the MMR by country in 2013, from 956·8 (685·1-1262·8) in South Sudan to 2·4 (1·6-3·6) in Iceland.

INTERPRETATION

Global rates of change suggest that only 16 countries will achieve the MDG 5 target by 2015. Accelerated reductions since the Millennium Declaration in 2000 coincide with increased development assistance for maternal, newborn, and child health. Setting of targets and associated interventions for after 2015 will need careful consideration of regions that are making slow progress, such as west and central Africa.

FUNDING

Bill & Melinda Gates Foundation.

Quantitative neurodegenerative pathology does not explain the degree of hippocampal atrophy on MRI in degenerative dementia

OBJECTIVE

The purpose of this study was to investigate the neuropathological substrates underlying in vivo hippocampal atrophy on magnetic resonance imaging (MRI) in autopsy confirmed neurodegenerative dementia cases.

METHODS

Thirty-one neuropathologically verified cases (23 with Lewy body dementia (LBD) and eight with Alzheimer's disease (AD)) were included who had undergone an MRI scan close to death (mean 1.5 years). Manual volumetric measurements were undertaken for the hippocampus, entorhinal cortex and amygdala on MRI, along with quantitative neuropathological analysis of plaque, tangle and Lewy body pathology in the same regions. The relationship between neuropathology and MRI volumes was assessed using correlations and linear regression.

RESULTS

Hippocampal and amygdala volumes were significantly smaller in cases with AD than with LBD, but there was no difference in entorhinal cortex volume. Analysing all cases together, a significant positive correlation was observed between normalised hippocampal volume and percent area of Lewy bodies in the hippocampus (r=0.449, p=0.017) but not with tangles (r=0.059, p=0.766) or plaques (r=-0.361, p=0.119). There were no other significant correlations between regional MRI volume and measures of neuropathology. Regression analysis showed that overall diagnosis of AD rather than burden of individual pathological changes was the most significant predictor of hippocampal volume loss in autopsy confirmed cases.

CONCLUSION

Our results suggest that (i) hippocampal and amygdala but not entorhinal cortex, volumes differ between AD and LBD and (ii) factors other than current markers of neurodegenerative pathological change are responsible for atrophy of medial temporal lobe structures in AD and LBD.

Health self-advocacy training for persons with intellectual disabilities

BACKGROUND

People with intellectual disabilities (ID) have unequal access to health care. While systemic efforts are addressing health inequalities, there remains a need to demonstrate that persons with ID can increase their health self-advocacy skills.

METHOD

A randomised control design with up to 6-month follow-up was used to evaluate the 3Rs (Rights, Respect and Responsibility) health self-advocacy training program for persons with ID (n = 31). Training involved teaching participants to recognise and redress health rights violations in the context of respect and responsibility. Training materials included PowerPoint slides and interactive video scenarios illustrating health rights, respect and responsibility problem and non-problems. Two-hour training sessions were conducted twice a week in a group format where participants played a game and answered questions.

RESULTS

The health rights training group made significantly more correct responses on post training and follow-up tests than the control group. Training effects generalised to untrained scenarios and in situ health interviews.

CONCLUSIONS

The results of this study suggest that persons with ID can learn complex skills related to health self-advocacy. More research is needed to improve in situ generalisation.

Degenerative Myelopathy in Two Boxer Dogs

Degenerative myelopathy (DM) is a common, slowly progressive, debilitating disease reported in several dog breeds, including the German Shepherd Dog and Pembroke Welsh Corgi. Boxer dogs present occasionally for a thoracolumbar myelopathy for which no cause is identified on MRI or cerebrospinal fluid analysis. Despite a lack of a histologic description of DM in the Boxer in the veterinary literature, such dogs are presumed to have DM. Here we report 2 histologically confirmed cases of DM in the Boxer breed in which histologic studies disclosed marked degenerative changes in the spinal cord that were most prominent in the thoracic and cranial lumbar segments. Lesions consisted of myelin vacuolation and degeneration, myelophagocytosis, reactive astrocytosis, and ellipsoid formation most prominent in the lateral and ventral funiculi. We present a detailed histologic description of DM in the Boxer dog and compare it to DM in other purebred dogs.

Medial temporal lobe atrophy on MRI differentiates Alzheimer's disease from dementia with Lewy bodies and vascular cognitive impairment: a prospective study with pathological verification of diagnosis

The purpose of this study was to determine the diagnostic accuracy of medial temporal lobe atrophy (MTA) on MRI for distinguishing Alzheimer's disease from other dementias in autopsy confirmed cases, and to determine pathological correlates of MTA in Alzheimer's disease, dementia with Lewy bodies (DLB) and vascular cognitive impairment (VCI). We studied 46 individuals who had both antemortem MRI and an autopsy. Subjects were clinicopathologically classified as having Alzheimer's disease (n = 11), DLB (n = 23) or VCI (n = 12). MTA was rated visually using a standardized (Scheltens) scale blind to clinical or autopsy diagnosis. Neuropathological analysis included Braak staging as well as quantitative analysis of plaques, tangles and alpha-synuclein Lewy body-associated pathology in the hippocampus. Correlations between MTA and pathological measures were carried out using Spearman's rho, linear regression to assess the contributions of local pathologic changes to MTA. Receiver operator curve analysis was used to assess the diagnostic specificity of MTA for Alzheimer's disease among individuals with Alzheimer's disease, DLB and VCI. MTA was a highly accurate diagnostic marker for autopsy confirmed Alzheimer's disease (sensitivity of 91% and specificity of 94%) compared with DLB and VCI. Across the entire sample, correlations were observed between MTA and Braak stage (rho = 0.50, P < 0.001), per cent area of plaques in the hippocampus (rho = 0.37, P = 0.014) and per cent area of tangles in the hippocampus (rho = 0.49, P = 0.001). Linear regression showed Braak stage (P = 0.022) to be a significant predictor of MTA but not percent area of plaques (P = 0.375), percent area of tangles (P = 0.330) or percent area of Lewy bodies (P = 0.086). MTA on MRI had robust discriminatory power for distinguishing Alzheimer's disease from DLB and VCI in pathologically confirmed cases. Pathologically, it is more strongly related to tangle rather than plaque or Lewy body pathology in the temporal lobe. It may have utility as a means for stratifying samples in vivo on the basis of putative differences in pathology.

Evaluation of the BD ProbeTec ET system for the direct detection of Mycobacterium tuberculosis from clinical samples

Early detection of disease caused by members of the Mycobacterium tuberculosis complex (MTBC) is essential in controlling transmission of tuberculosis. Clinical evaluation of the BD ProbeTec ET system for the direct detection of MTBC organisms in clinical specimens is carried out by comparing results obtained with conventional liquid culture and reference laboratory identification. In 186 specimens (159 respiratory, 27 non-respiratory), the BD ProbeTec ET assay detected eight out of 11 MTBC culture-positive specimens, with overall sensitivity, specificity, positive predictive value and negative predictive value of 85%, 100%, 100% and 99%, respectively. The data show that the BD ProbeTec ET assay is a highly sensitive and specific technique, and gives an accurate result from a clinical specimen within three to four hours.

White matter lesions in an unselected cohort of the elderly: astrocytic, microglial and oligodendrocyte precursor cell responses

White matter lesions in an unselected cohort of the elderly: astrocytic, microglial and oligodendrocyte precursor cell responsesHyperintense lesions are frequently identified in T2-weighted magnetic resonance images (MRI) in the ageing brain. The pathological correlate and pathogenesis of white matter lesions (WML) remain unclear, and it is uncertain whether pathology and pathogenesis differ in periventricular lesions (PVL) compared with deep subcortical lesions (DSCL). Therefore we characterized astrocytic, microglial and oligodendrocyte responses in PVL and DSCL and compared them with control white matter using immunohistochemistry. Both PVL and DSCL were associated with severe myelin loss and increased microglia (P = 0.069 and P < 0.001), compared with nonlesional aged brain. Clasmatodendritic astroglia, immunoreactive for the serum protein fibrinogen, were present in 67% of PVL examined and 42% of DSCL. Compared with control and DSCL cases, more MAP-2 +13 positive remyelinating oligodendrocytes (P = 0.003 and P = 0.035) and platelet-derived growth factor alpha receptor positive reactive astrocytes (P < 0.001) were present in the perilesional white matter of PVL. In addition to a role for hypoperfusion, our data suggest that dysfunction of the blood-brain barrier may also contribute to the pathogenesis of a proportion of cerebral WML associated with ageing, and that attempts at remyelination are only associated with PVL and not DSCL.

APOE epsilon4 and cognitive decline in older stroke patients with early cognitive impairment

BACKGROUND

Dementia is common post stroke, but the potential role of early cognitive impairment and APOE epsilon4 as risk factors is unclear.

METHOD

Stroke survivors older than 75 years without dementia at 3 months post stroke received a detailed neuropsychological evaluation at 3 and 15 months post stroke, which included the Cambridge Assessment of Mental Disorders in the Elderly (CAMCOG). Early cognitive impairment was diagnosed using the criteria for cognitive impairment/no dementia (vascular CIND). APOE genotype was determined using a standardized method.

RESULTS

One hundred thirty-seven older stroke patients without dementia (mean age 80.6 +/- 4.3, mean CAMCOG score 83.5 +/- 10.4, 68 women) participated in the study, of whom 40 met the criteria for CIND. Stroke patients with one or more APOE epsilon4 alleles were significantly more likely to have CIND (14/40 vs 17/97, odds ratio = 2.5, 95% CI 1.1 to 5.8). Over the 1 year of follow-up, CIND patients with one or more APOE epsilon4 alleles had a mean decline on the total CAMCOG of 2.7 points compared with an improvement of >4 points among patients without APOE epsilon4 (T = 2.9 p = 0.006). CIND patients with an APOE epsilon4 allele also experienced greater decline in memory (T = 2.5, p = 0.015).

CONCLUSION

In older stroke patients with early cognitive impairment, the presence of an APOE epsilon4 allele is associated with greater progression of cognitive decline. This has implications for interventions aimed at the secondary prevention of dementia in stroke patients.

Deep Impact: observations from a worldwide Earth-based campaign

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

NINDS AIREN neuroimaging criteria do not distinguish stroke patients with and without dementia

OBJECTIVE

To determine the utility of the neuroimaging component within the National Institute of Neurological Disorders and Stroke (NINDS) Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN) criteria for vascular dementia for distinguishing between patients with and without dementia in the context of cerebrovascular disease.

METHOD

One hundred twenty-five poststroke patients age > or =75 (27 with and 98 without poststroke dementia) from representative hospital-based stroke registers in the North East of England were evaluated using a 1.5 T MR scanner. The proportion of patients with and without poststroke dementia meeting the imaging component of the NINDS AIREN criteria was determined, and hippocampal atrophy (measured using the Schelten scale) was compared between the two groups.

RESULTS

There were no significant differences between the patients with and without poststroke dementia on any criteria of the imaging parameters within the NINDS AIREN criteria. In addition, there were no significant differences in the number or size of cortical or subcortical infarcts between the two groups, with 13 patients without dementia having cortical infarcts >50 mm. Patients with dementia had greater hippocampal atrophy (right: Mann-Whitney U test, Z = 2.5, p = 0.01; left: Mann-Whitney U test, Z = 2.5, p = 0.01).

CONCLUSION

The neuroimaging component of the NINDS AIREN criteria does not distinguish between older patients with and without poststroke dementia.

Hippocampal atrophy, whole brain volume, and white matter lesions in older hypertensive subjects

OBJECTIVE

To determine the potential role of whole brain atrophy, hippocampal atrophy, or both, and small vessel disease/white matter lesions as mechanisms underlying the cognitive impairment associated with hypertension.

METHODS

Using MRI scanning the authors determined hippocampal volumes, whole brain volumes, and location and severity of white matter lesions, using Scheltens scale, in 103 hypertensive (166 +/- 8/88 +/- 7 mm Hg, 54 female) and 51 normotensive (132 +/- 12/74 +/- 7 mm Hg, 21 female) subjects age > or = 70 years.

RESULTS

Compared to normotensive subjects, older hypertensive subjects had significantly smaller whole brain volumes (887 +/- 109 vs 930 +/- 97 cm3, p = 0.02) and nonsignificantly reduced hippocampal volumes (5.39 +/- 1.60 vs 5.67 +/- 1.80 cm3, p = 0.33). Hypertensive subjects had an increased burden of periventricular lesions: bands (p = 0.03), frontal caps (p = 0.08), occipital caps (p = 0.07), and total periventricular hyperintensities (p = 0.02). They also had higher scores in subcortical areas: frontal (p = 0.04), temporal (p = 0.03), and deep white matter areas (p = 0.05). A correlation was found between whole brain volumes and systolic blood pressure (r = -0.19, p = 0.02). No correlation was seen between whole brain volumes and white matter lesion burden.

CONCLUSIONS

Moderate hypertension in non-impaired older subjects is associated with smaller whole brain volume and an increased burden of subcortical and periventricular white matter lesions.

The application of serial MRI analysis techniques to the study of cerebral atrophy in late-onset dementia

We have used a serial MR image analysis technique previously developed for studies of cerebral atrophy in early-onset dementia and applied it to a study of late-onset dementia patients with images acquired using a different scanner and scan sequence. Validation and optimisation tests showed that with only small changes to key analysis parameters the technique can successfully be applied to previously untested data with dissimilar image characteristics. The overall accuracy in estimation of cerebral atrophy using the technique was determined to be between 2 and 4 ml (1sigma) depending on the conditions during image acquisition. By comparing the results of alternative registration techniques we demonstrate the potential of using of fully automated 9 DOF image registration as an effective and efficient means of correcting for scanner pixel size variations, even in the presence of significant cerebral atrophy. Applied to the late-onset dementia study, patients were found to have significantly increased mean atrophy rates (p<0.001) compared to controls. In general the analysis technique is shown to be a robust, accurate and transferable tool of potential value for future studies of dementia and related neuro-degenerative disorders.

Comparison of the pathology of cerebral white matter with post-mortem magnetic resonance imaging (MRI) in the elderly brain

White matter lesions (WML) on magnetic resonance imaging (MRI) brain scans are associated with ageing. They are unrelated to specific disorders, and their impact on cognitive and other brain functions is poorly characterized. Pathological studies often omit systematic survey of WML because of the need to study multiple full coronal tissue blocks, and uncertainty over the significance of lesions identified in periventricular and deep subcortical regions. Post-mortem MRI provides a means of mapping WML but the sensitivity and specificity of the method are unresolved. In this study post-mortem MRI of WML in fixed brain slices was compared with pathology in 33 brains donated to the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS). This study shows that MRI detection of WML was less sensitive than pathology: periventricaular lesions (PVL) sensitivity = 95% (87-99%), specificity = 71% (44-90%); deep subcortical lesions (DSCL) sensitivity = 86% (79-93%), specificity = 80% (72-88%). False negative MRI was associated with milder pathology, but lesions detected by myelin attenuation alone showed both microglial and endothelial activation. Therefore post-mortem MRI of formalin-fixed brain slices is a reliable method to obtain systematic data on the severity and distribution of cerebral white matter disease, and appears to detect those WML most likely to have clinical impact.

Visual rating of age-related white matter changes on magnetic resonance imaging: scale comparison, interrater agreement, and correlations with quantitative measurements

BACKGROUND AND PURPOSE

To provide further insight into the MRI assessment of age-related white matter changes (ARWMCs) with visual rating scales, 3 raters with different levels of experience tested the interrater agreement and comparability of 3 widely used rating scales in a cross-sectional and follow-up setting. Furthermore, the correlation between visual ratings and quantitative volumetric measurement was assessed.

METHODS

Three raters from different sites using 3 established rating scales (Manolio, Fazekas and Schmidt, Scheltens) evaluated 74 baseline and follow-up scans from 5 European centers. One investigator also rated baseline scans in a set of 255 participants of the Austrian Stroke Prevention Study (ASPS) and measured the volume of ARWMCs.

RESULTS

The interrater agreement for the baseline investigation was fair to good for all scales (kappa values, 0.59 to 0.78). On the follow-up scans, all 3 raters depicted significant ARWMC progression; however, the direct interrater agreement for this task was poor (kappa, 0.19 to 0.39). Comparison of the interrater reliability between the 3 scales revealed a statistical significant difference between the scale of Manolio and that of Fazekas and Schmidt for the baseline investigation (z value, -2.9676; P=0.003), demonstrating better interrater agreement for the Fazekas and Schmidt scale. The rating results obtained with all 3 scales were highly correlated with each other (Spearman rank correlation, 0.712 to 0.806; P< or =0.01), and there was significant agreement between all 3 visual rating scales and the quantitative volumetric measurement of ARWMC (Kendall W, 0.37, 0.48, and 0.57; P<0.001).

CONCLUSIONS

Our data demonstrate that the 3 rating scales studied reflect the actual volume of ARWMCs well. The 2 scales that provide more detailed information on ARWMCs seemed preferential compared with the 1 that yields more global information. The visual assessment of ARWMC progression remains problematic and may require modifications or extensions of existing rating scales.

Patterns of cerebral atrophy in dementia with Lewy bodies using voxel-based morphometry

Previous cross-sectional MRI studies based on region-of-interest analyses have shown that increased cerebral atrophy is a feature of both Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Relative preservation of the hippocampus and temporal lobe structures in DLB compared to AD has been reported in region-of-interest-based studies. Recently, image processing techniques such as voxel-based morphometry (VBM) have been developed to provide an unbiased, visually informative, and comprehensive means of studying patterns of cerebral atrophy. We report the first study to use the voxel-based approach to assess patterns of cerebral atrophy in DLB compared to control subjects and AD. Regional gray matter volume loss was observed bilaterally in the temporal and frontal lobes and insular cortex of patients with DLB compared to control subjects. Comparison of dementia groups showed preservation of the medial temporal lobe, hippocampus, and amygdala in DLB relative to AD. Significant gray matter loss was also observed in the thalamus of AD patients compared to DLB.