Remeasuring the influence of ageing on heat-related mortality in Spain, 1980 to 2018

Climate change and population ageing are converging challenges that are expected to significantly worsen the health impacts of high temperatures. We aimed to remeasure the implications of ageing for heat-related mortality by comparing time trends based on chronological age (number of years already lived) with those derived from the application of state-of-the-art demographic methodology which better captures the dynamics of evolving longevity: prospective age (number of years still to be lived). We conducted a nationwide time-series analysis of 13 regions in Spain over 1980-2018 using all-cause mortality microdata for people aged 65+ and annual life tables from the Spanish National Institute of Statistics, and daily mean temperatures from E-OBS. Based on confounder-adjusted quasi-Poisson regression with distributed lag non-linear models and multivariate meta-analysis in moving 15-year timeslices, we assessed sex-specific changes in absolute risk and impacts for heat-related mortality at extreme and moderate temperatures, for chronological and prospective age groups. In the conventional chronological age analysis, absolute risk fell over the study period (e.g. females, extreme heat: -54%; moderate heat: -23%); after accounting for rising longevity, the prospective age analysis, however, found a smaller decline in risk for extreme heat (-15%) and a rise for moderate heat (+46%). Additionally, while the chronological age analysis suggested a shift in mortality towards higher ages, the prospective age analysis showed that over the study period, people of largely the same (prospective) age were impacted. Further, the prospective age analysis revealed excess risk in females (compared to males) rose from 20% to 27% for extreme heat, and from 40% to 70% for moderate heat. Assessing the implications of ageing using a prospective age perspective showed the urgency of re-doubling risk reduction efforts, including accelerating healthy ageing programs that incorporate climate considerations. The age patterns of impacts suggested that such actions have the potential to mitigate ageing-related heat-health threats to generate climate change-ready, healthy societies.

Ambient temperature and risk of cardiovascular and respiratory adverse health outcomes: a nationwide cross-sectional study from Spain

AIMS

We assessed the association of temperature and temperature variability with cause-specific emergency hospitalizations and mortality from cardiovascular and respiratory diseases in Spain, as well as the effect modification of this association by individual and contextual factors.

METHODS AND RESULTS

We collected data on health (hospital admissions and mortality), weather (temperature and relative humidity), and relevant contextual indicators for 48 Spanish provinces during 2004-2019. The statistical analysis was separately performed for the summer (June-September) and winter (December-March) seasons. We first applied a generalized linear regression model with quasi-Poisson distribution to estimate daily province-specific temperature-health associations, and then we fitted multilevel multivariate meta-regression models to the evaluate effect modification of the contextual characteristics on heat- and cold-related risks. High temperature increased the risk of mortality across all cardiovascular and respiratory diseases, with the strongest effect for hypertension (relative risk (RR) at 99th temperature percentile vs. optimum temperature: 1.510 [95% empirical confidence interval {eCI} 1.251 to 1.821]), heart failure (1.528 [1.353 to 1.725]), and pneumonia (2.224 [1.685 to 2.936]). Heat also had an impact on all respiratory hospitalization causes (except asthma), with similar risks between pneumonia (1.288 [1.240 to 1.339]), acute bronchitis and bronchiolitis (1.307 [1.219 to 1.402]), and chronic obstructive pulmonary disease (1.260 [1.158 to 1.372]). We generally found significant risks related to low temperature for all cardiovascular and respiratory causes, with heart failure (RR at 1st temperature percentile vs. optimum temperature: 1.537 [1.329 to 1.779]) and chronic obstructive pulmonary disease (1.885 [1.646 to 2.159]) exhibiting the greatest risk for hospitalization, and acute myocardial infarction (1.860 [1.546 to 2.238]) and pneumonia (1.734 [1.219 to 2.468]) for mortality. Women and the elderly were more vulnerable to heat, while people with secondary education were less susceptible to cold compared to those not achieving this educational stage. Results from meta-regression showed that increasing heating access to the highest current provincial value (i.e. 95.6%) could reduce deaths due to cold by 59.5% (57.2 to 63.5).

CONCLUSION

Exposure to low and high temperatures was associated with a greater risk of morbidity and mortality from multiple cardiovascular and respiratory conditions, and heating was the most effective societal adaptive measure to reduce cold-related mortality.

Drivers of the time-varying heat-cold-mortality association in Spain: A longitudinal observational study

BACKGROUND

A number of studies have reported reductions in mortality risk due to heat and cold over time. However, questions remain about the drivers of these adaptation processes to ambient temperatures. We aimed to analyse the demographic and socioeconomic drivers of the downward trends in vulnerability to heat- and cold-related mortality observed in Spain during recent decades (1980-2018).

METHODS

We collected data on all-cause mortality, temperature and relevant contextual indicators for 48 provinces in mainland Spain and the Balearic Islands between Jan 1, 1980, and Dec 31, 2018. Fourteen contextual indicators were analysed representing ageing, isolation, urbanicity, heating, air conditioning (AC), house antiquity and ownership, education, life expectancy, macroeconomics, socioeconomics, and health investment. The statistical analysis was separately performed for the range of months mostly causing heat- (June-September) and cold- (October-May) related mortality. We first applied a quasi-Poisson generalised linear regression in combination with distributed lag non-linear models (DLNM) to estimate province-specific temperature-mortality associations for different periods, and then we fitted univariable and multivariable multilevel spatiotemporal meta-regression models to evaluate the effect modification of the contextual characteristics on heat- and cold-related mortality risks over time.

FINDINGS

The average annual mean temperature has risen at an average rate of 0·36 °C per decade in Spain over 1980-2012, although the increase in temperature has been more pronounced in summer (0·40 °C per decade in June-September) than during the rest of the year (0·33 °C per decade). This warming has been observed, however, in parallel with a progressive reduction in the mortality risk associated to both hot and cold temperatures. We found independent associations for AC with heat-related mortality, and heating with cold-related mortality. AC was responsible for about 28·6% (31·5%) of the decrease in deaths due to heat (extreme heat) between 1989 and 1993 and 2009-2013, and heating for about 38·3% (50·8%) of the reductions in deaths due to cold (extreme cold) temperatures. Ageing (ie, proportion of population over 64 years) attenuated the decrease in cold-related mortality.

INTERPRETATION

AC and heating are effective societal adaptive measures to heat and cold temperatures. This evidence holds important implications for climate change health adaptation policies, and for the projections of climate change impacts on human health.

The Direct and Indirect Influences of Interrelated Regional-Level Sociodemographic Factors on Heat-Attributable Mortality in Europe: Insights for Adaptation Strategies

BACKGROUND

Heat is a significant cause of mortality, but impact patterns are heterogenous. Previous studies assessing such heterogeneity focused exclusively on risk rather than heat-attributable mortality burdens and assume predictors are independent.

OBJECTIVES

We assessed how four interrelated regional-level sociodemographic predictors-education, life expectancy, the ratio of older to younger people (aging index), and relative income-influence heterogeneity in heat-attributable mortality burdens in Europe and then derived insights into adaptation strategies.

METHODS

We extracted four outcomes from a temperature-mortality study covering 16 European countries: the rate of increase in mortality risk at moderate and extreme temperatures (moderate and extreme slope, respectively), the minimum mortality temperature percentile (MMTP), and the underlying mortality rate. We used structural equation modeling with country-level random effects to quantify the direct and indirect influences of the predictors on the outcomes.

RESULTS

Higher levels of education were directly associated with lower heat-related mortality at moderate and extreme temperatures via lower slopes and higher MMTPs. A one standard deviation increase in education was associated with a - 0.46 ± 0.14 , - 0.41 ± 0.12 , and 0.41 ± 0.12 standard deviation (± standard error ) change in the moderate slope, extreme slope, and MMTP, respectively. However, education had mixed indirect influences via associations with life expectancy, the aging index, and relative income. Higher life expectancy had mixed relations with heat-related mortality, being associated with higher risk at moderate temperatures (0.33 ± 0.11 for the moderate slope; - 0.19 ± 0.097 for the MMTP) but lower underlying mortality rates (- 0.72 ± 0.097 ). A higher aging index was associated with higher burdens through higher risk at extreme temperatures (0.13 ± 0.072 for the extreme slope) and higher underlying mortality rates (0.93 ± 0.055 ). Relative income had relatively small, mixed influences.

DISCUSSION

Our novel approach provided insights into actions for reducing the health impacts of heat. First, the results show the interrelations between possible vulnerability-generating mechanisms and suggest future research directions. Second, the findings point to the need for a dual approach to adaptation, with actions that explicitly target heat exposure reduction and actions focused explicitly on the root causes of vulnerability. For the latter, the climate crisis may be leveraged to accelerate ongoing general public health programs. https://doi.org/10.1289/EHP11766.

Model Choice for Quantitative Health Impact Assessment and Modelling: An Expert Consultation and Narrative Literature Review

BACKGROUND

Health impact assessment (HIA) is a widely used process that aims to identify the health impacts, positive or negative, of a policy or intervention that is not necessarily placed in the health sector. Most HIAs are done prospectively and aim to forecast expected health impacts under assumed policy implementation. HIAs may quantitatively and/ or qualitatively assess health impacts, with this study focusing on the former. A variety of quantitative modelling methods exist that are used for forecasting health impacts, however, they differ in application area, data requirements, assumptions, risk modelling, complexities, limitations, strengths, and comprehensibility. We reviewed relevant models, so as to provide public health researchers with considerations for HIA model choice.

METHODS

Based on an HIA expert consultation, combined with a narrative literature review, we identified the most relevant models that can be used for health impact forecasting. We narratively and comparatively reviewed the models, according to their fields of application, their configuration and purposes, counterfactual scenarios, underlying assumptions, health risk modelling, limitations and strengths.

RESULTS

Seven relevant models for health impacts forecasting were identified, consisting of (i) comparative risk assessment (CRA), (ii) time series analysis (TSA), (iii) compartmental models (CMs), (iv) structural models (SMs), (v) agent-based models (ABMs), (vi) microsimulations (MS), and (vii) artificial intelligence (AI)/machine learning (ML). These models represent a variety in approaches and vary in the fields of HIA application, complexity and comprehensibility. We provide a set of criteria for HIA model choice. Researchers must consider that model input assumptions match the available data and parameter structures, the available resources, and that model outputs match the research question, meet expectations and are comprehensible to end-users.

CONCLUSION

The reviewed models have specific characteristics, related to available data and parameter structures, computational implementation, interpretation and comprehensibility, which the researcher should critically consider before HIA model choice.

Thinking Health-related Behaviors in a Climate Change Context: A Narrative Review

BACKGROUND

Human activities have changed the environment so profoundly over the past two centuries that human-induced climate change is now posing serious health-related threats to current and future generations. Rapid action from all scientific fields, including behavioral medicine, is needed to contribute to both mitigation of, and adaption to, climate change.

PURPOSE

This article aims to identify potential bi-directional associations between climate change impacts and health-related behaviors, as well as a set of key actions for the behavioral medicine community.

METHODS

We synthesized the existing literature about (i) the impacts of rising temperatures, extreme weather events, air pollution, and rising sea level on individual behaviors (e.g., eating behaviors, physical activity, sleep, substance use, and preventive care) as well as the structural factors related to these behaviors (e.g., the food system); and (ii) the concurrent positive and negative roles that health-related behaviors can play in mitigation and adaptation to climate change.

RESULTS

Based on this literature review, we propose a first conceptual model of climate change and health-related behavior feedback loops. Key actions are proposed, with particular consideration for health equity implications of future behavioral interventions. Actions to bridge the fields of behavioral medicine and climate sciences are also discussed.

CONCLUSIONS

We contend that climate change is among the most urgent issues facing all scientists and should become a central priority for the behavioral medicine community.

Developing a programme theory for a transdisciplinary research collaboration: Complex Urban Systems for Sustainability and Health

Background: Environmental improvement is a priority for urban sustainability and health and achieving it requires transformative change in cities. An approach to achieving such change is to bring together researchers, decision-makers, and public groups in the creation of research and use of scientific evidence. Methods: This article describes the development of a programme theory for Complex Urban Systems for Sustainability and Health (CUSSH), a four-year Wellcome-funded research collaboration which aims to improve capacity to guide transformational health and environmental changes in cities. Results: Drawing on ideas about complex systems, programme evaluation, and transdisciplinary learning, we describe how the programme is understood to "work" in terms of its anticipated processes and resulting changes. The programme theory describes a chain of outputs that ultimately leads to improvement in city sustainability and health (described in an 'action model'), and the kinds of changes that we expect CUSSH should lead to in people, processes, policies, practices, and research (described in a 'change model'). Conclusions: Our paper adds to a growing body of research on the process of developing a comprehensive understanding of a transdisciplinary, multiagency, multi-context programme. The programme theory was developed collaboratively over two years. It involved a participatory process to ensure that a broad range of perspectives were included, to contribute to shared understanding across a multidisciplinary team. Examining our approach allowed an appreciation of the benefits and challenges of developing a programme theory for a complex, transdisciplinary research collaboration. Benefits included the development of teamworking and shared understanding and the use of programme theory in guiding evaluation. Challenges included changing membership within a large group, reaching agreement on what the theory would be 'about', and the inherent unpredictability of complex initiatives.

Developing a programme theory for a transdisciplinary research collaboration: Complex Urban Systems for Sustainability and Health

Background: Environmental improvement is a priority for urban sustainability and health and achieving it requires transformative change in cities. An approach to achieving such change is to bring together researchers, decision-makers, and public groups in the creation of research and use of scientific evidence.

Methods: This article describes the development of a programme theory for Complex Urban Systems for Sustainability and Health (CUSSH), a four-year Wellcome-funded research collaboration which aims to improve capacity to guide transformational health and environmental changes in cities.

Results: Drawing on ideas about complex systems, programme evaluation, and transdisciplinary learning, we describe how the programme is understood to “work” in terms of its anticipated processes and resulting changes. The programme theory describes a chain of outputs that ultimately leads to improvement in city sustainability and health (described in an ‘action model’), and the kinds of changes that we expect CUSSH should lead to in people, processes, policies, practices, and research (described in a ‘change model’).

Conclusions: Our paper adds to a growing body of research on the process of developing a comprehensive understanding of a transdisciplinary, multiagency, multi-context programme. The programme theory was developed collaboratively over two years. It involved a participatory process to ensure that a broad range of perspectives were included, to contribute to shared understanding across a multidisciplinary team. Examining our approach allowed an appreciation of the benefits and challenges of developing a programme theory for a complex, transdisciplinary research collaboration. Benefits included the development of teamworking and shared understanding and the use of programme theory in guiding evaluation. Challenges included changing membership within a large group, reaching agreement on what the theory would be ‘about’, and the inherent unpredictability of complex initiatives.

A tool for assessing the climate change mitigation and health impacts of environmental policies: the Cities Rapid Assessment Framework for Transformation (CRAFT)

Background: A growing number of cities, including Greater London, have set ambitious targets, including detailed policies and implementation plans, to reach global goals on sustainability, health, and climate change. Here we present a tool for a rapid assessment of the magnitude of impact of specific policy initiatives to reach these targets. The decision-support tool simultaneously quantifies the environmental and health impacts of specified selected policies. Methods: The 'Cities Rapid Assessment Framework for Transformation (CRAFT)' tool was applied to Greater London. CRAFT quantifies the effects of ten environmental policies on changes in (1) greenhouse gas (GHG) emissions, (2) exposures to environmental hazards, (3) travel-related physical activity, and (4) mortality (the number of attributable deaths avoided in one typical year). Publicly available data and epidemiological evidence were used to make rapid quantitative estimates of these effects based on proportional reductions in GHG emissions and environmental exposures from current baseline levels and to compute the mortality impacts. Results: The CRAFT tool estimates that, of roughly 50,000 annual deaths in Greater London, the modelled hazards (PM 2.5 (from indoor and outdoor sources), outdoor NO 2, indoor radon, cold, overheating) and low travel-related physical activity are responsible for approximately 10,000 premature environment-related deaths. Implementing the selected polices could reduce the annual mortality number by about 20% (~1,900 deaths) by 2050. The majority of these deaths (1,700) may be avoided through increased uptake in active travel. Thus, out of ten environmental policies, the 'active travel' policy provides the greatest health benefit. Also, implementing the ten policies results in a GHG reduction of around 90%. Conclusions: The CRAFT tool quantifies the effects of city policies on reducing GHG emissions, decreasing environmental health hazards, and improving public health. The tool has potential value for policy makers through providing quantitative estimates of health impacts to support and prioritise policy options.

Climate change, hunger and rural health through the lens of farming styles: An agent-based model to assess the potential role of peasant farming

Undernutrition is a major contributor to the global-burden of disease, and global-level health impact models suggest that climate change-mediated reductions in food quantity and quality will negatively affect it. These models, however, capture just some of the processes that will shape future nutrition. We adopt an alternative standpoint, developing an agent-based model in which producer-consumer smallholders practice different ‘styles of farming’ in the global food system. The model represents a hypothetical rural community in which ‘orphan’ (subsistence) farmers may develop by adopting an ‘entrepreneurial’ style (highly market-dependent) or by maintaining a ‘peasant’ style (agroecology). We take a first look at the question: how might patterns of farming styles—under various style preference, climate, policy, and price transmission scenarios—impact on hunger and health-supporting conditions (incomes, work, inequality, ‘real land productivity’) in rural areas? imulations without climate change or agricultural policy found that style preference patterns influence production, food price, and incomes, and there were trade-offs between them. For instance, entrepreneurial-oriented futures had the highest production and lowest prices but were simultaneously those in which farms tended towards crisis. Simulations with climate change and agricultural policy found that peasant-orientated agroecology futures had the highest production, prices equal to or lower than those under entrepreneurial-oriented futures, and better supported rural health. There were, however, contradictory effects on nutrition, with benefits and harms for different groups. Collectively the findings suggest that when attempting to understand how climate change may impact on future nutrition and health, patterns of farming styles—along with the fates of the households that practice them—matter. These issues, including the potential role of peasant farming, have been neglected in previous global-level climate-nutrition modelling but go to the heart of current debates on the future of farming: thus, they should be given more prominence in future work.

A tool for assessing the climate change mitigation and health impacts of environmental policies: the Cities Rapid Assessment Framework for Transformation (CRAFT)

Background: A growing number of cities, including Greater London, have set ambitious targets, including detailed policies and implementation plans, to reach global goals on sustainability, health, and climate change. Here we present a tool for a rapid assessment of the magnitude of impact of specific policy initiatives to reach these targets. The decision-support tool simultaneously quantifies the environmental and health impacts of specified selected policies. Methods: The 'Cities Rapid Assessment Framework for Transformation (CRAFT)' tool was applied to Greater London. CRAFT quantifies the effects of ten environmental policies on changes in (1) greenhouse gas (GHG) emissions, (2) exposures to environmental hazards, (3) travel-related physical activity, and (4) mortality (the number of attributable deaths avoided in one typical year). Publicly available data and epidemiological evidence were used to make rapid quantitative estimates of these effects based on proportional reductions in GHG emissions and environmental exposures from current baseline levels and to compute the mortality impacts. Results: The CRAFT tool estimates that, of roughly 50,000 annual deaths in Greater London, the modelled hazards (PM 2.5 (from indoor and outdoor sources), outdoor NO 2, indoor radon, cold, overheating) and low travel-related physical activity are responsible for approximately 10,000 premature environment-related deaths. Implementing the selected polices could reduce the annual mortality number by about 20% (~1,900 deaths) by 2050. The majority of these deaths (1,700) may be avoided through increased uptake in active travel. Thus, out of ten environmental policies, the 'active travel' policy provides the greatest health benefit. Also, implementing the ten policies results in a GHG reduction of around 90%. Conclusions: The CRAFT tool quantifies the effects of city policies on reducing GHG emissions, decreasing environmental health hazards, and improving public health. The tool has potential value for policy makers through providing quantitative estimates of health impacts to support and prioritise policy options.

A Global-Level Model of the Potential Impacts of Climate Change on Child Stunting via Income and Food Price in 2030

BACKGROUND

In 2016, 23% of children (155 million) aged [Formula: see text] were stunted. Global-level modeling has consistently found climate change impacts on food production are likely to impair progress on reducing undernutrition.

OBJECTIVES

We adopt a new perspective, assessing how climate change may affect child stunting via its impacts on two interacting socioeconomic drivers: incomes of the poorest 20% of populations (due to climate impacts on crop production, health, labor productivity, and disasters) and food prices.

METHODS

We developed a statistical model to project moderate and severe stunting in children aged [Formula: see text] at the national level in 2030 under low and high climate change scenarios combined with poverty and prosperity scenarios in 44 countries.

RESULTS

We estimated that in the absence of climate change, 110 million children aged [Formula: see text] would be stunted in 2030 under the poverty scenario in comparison with 83 million under the prosperity scenario. Estimates of climate change-attributable stunting ranged from 570,000 under the prosperity/low climate change scenario to [Formula: see text] under the poverty/high climate change scenario. The projected impact of climate change on stunting was greater in rural vs. urban areas under both socioeconomic scenarios. In countries with lower incomes and relatively high food prices, we projected that rising prices would tend to increase stunting, whereas in countries with higher incomes and relatively low food prices, rising prices would tend to decrease stunting. These findings suggest that food prices that provide decent incomes to farmers alongside high employment with living wages will reduce undernutrition and vulnerability to climate change.

CONCLUSIONS

Shifting the focus from food production to interactions between incomes and food price provides new insights. Futures that protect health should consider not just availability, accessibility, and quality of food, but also the incomes generated by those producing the food. https://doi.org/10.1289/EHP2916.

Climate change, crop yields, and undernutrition: development of a model to quantify the impact of climate scenarios on child undernutrition

BACKGROUND

Global climate change is anticipated to reduce future cereal yields and threaten food security, thus potentially increasing the risk of undernutrition. The causation of undernutrition is complex, and there is a need to develop models that better quantify the potential impacts of climate change on population health.

OBJECTIVES

We developed a model for estimating future undernutrition that accounts for food and nonfood (socioeconomic) causes and can be linked to available regional scenario data. We estimated child stunting attributable to climate change in five regions in South Asia and sub-Saharan Africa (SSA) in 2050.

METHODS

We used current national food availability and undernutrition data to parameterize and validate a global model, using a process-driven approach based on estimations of the physiological relationship between a lack of food and stunting. We estimated stunting in 2050 using published modeled national calorie availability under two climate scenarios and a reference scenario (no climate change).

RESULTS

We estimated that climate change will lead to a relative increase in moderate stunting of 1-29% in 2050 compared with a future without climate change. Climate change will have a greater impact on rates of severe stunting, which we estimated will increase by 23% (central SSA) to 62% (South Asia).

CONCLUSIONS

Climate change is likely to impair future efforts to reduce child malnutrition in South Asia and SSA, even when economic growth is taken into account. Our model suggests that to reduce and prevent future undernutrition, it is necessary to both increase food access and improve socioeconomic conditions, as well as reduce greenhouse gas emissions.

Quantitative PCR demonstrates a positive correlation between a Rickettsia-like organism and severity of strawberry disease lesions in rainbow trout, Oncorhynchus mykiss (Walbaum)

Strawberry disease (SD) is an inflammatory skin disorder in rainbow trout, Oncorhynchus mykiss (Walbaum). The aetiology of SD is unknown although the 16S rDNA sequence of a Rickettsia-like organism (RLO) has been associated with SD lesions using a nested PCR assay. In this study, we developed a Taqman quantitative PCR assay (qPCR) that targeted the RLO 16S rDNA sequence to examine the distribution of RLO relative to lesion status. We compared 18 lesion samples from 13 fish representing high or low lesion severity as judged by gross examination. QPCR results showed that there was a higher number of RLO sequences in high severity lesions (mean of 12,068 copies) compared with fewer copies of RLO sequence in low severity lesions (mean of 3287 copies, P = 0.012). Grossly normal skin samples (n = 13) from SD-affected fish were all negative by qPCR except two samples (121 and 139 copies). The qPCR assay described herein is a useful tool to investigate the role of RLO in SD in the absence of a culture system for RLO. Our results demonstrate a positive correlation between copy number and lesion severity consistent with the hypothesis that the RLO is the aetiologic agent of SD.

Association of red-mark syndrome with a Rickettsia-like organism and its connection with strawberry disease in the USA

Red-mark syndrome (RMS), a disease seen mostly in rainbow trout, Oncorhynchus mykiss, is of unknown aetiology. The research presented here indicates the presence of an intracellular bacterium in RMS-affected fish. A positive reaction was observed using immunohistochemistry (IHC) with skin lesions, liver, kidney and spleen of affected fish sampled from several locations within the United Kingdom using two different polyclonal antisera raised against Piscirickettsia salmonis. The same reaction was also seen with a number of different anti-P. salmonis monoclonal antibodies (MAbs). A disease with similar clinical signs to RMS, referred to as strawberry disease (SD), has been reported in the USA. A Rickettsia-like organism (RLO) has recently been associated with SD based on analysis of 16S rDNA sequences. Using the same panel of anti-P. salmonis antibodies used to screen the RMS samples, similar staining was obtained in tissue of SD-affected fish by IHC. A polymerase chain reaction (PCR) using RLO-specific primers was also performed on RMS-affected fish from the United Kingdom, and the samples were positive for the RLO 16S rRNA sequence. These findings suggest that the same aetiological agent may be responsible for RMS in the United Kingdom and SD in the USA.

The direct impact of climate change on regional labor productivity

Global climate change will increase outdoor and indoor heat loads, and may impair health and productivity for millions of working people. This study applies physiological evidence about effects of heat, climate guidelines for safe work environments, climate modeling, and global distributions of working populations to estimate the impact of 2 climate scenarios on future labor productivity. In most regions, climate change will decrease labor productivity, under the simple assumption of no specific adaptation. By the 2080s, the greatest absolute losses of population-based labor work capacity (in the range 11% to 27%) are seen under the A2 scenario in Southeast Asia, Andean and Central America, and the Caribbean. Increased occupational heat exposure due to climate change may significantly impact on labor productivity and costs unless preventive measures are implemented. Workers may need to work longer hours, or more workers may be required, to achieve the same output and there will be economic costs of lost production and/or occupational health interventions against heat exposures.

Structural characterization of TiN/NbN multilayers: X-ray diffraction, energy-filtered TEM and Fresnel contrast techniques compared

Two TiN/NbN multilayers with wavelength 13.6 and 6.15 nm have been characterized by X-ray diffraction (XRD), Fresnel contrast analysis (FCA) and energy-filtered transmission electron microscopy (EFTEM). Good agreement between the composition profile obtained by FCA and EFTEM is obtained if the lower resolution of the EFTEM images is taken into account. The relative advantages and disadvantages of the techniques are discussed. Used together the two TEM techniques provide a quantitative characterization that is consistent with, and for some parameters provides more precise values than, that from XRD. The analysis shows that the multilayers have narrow interfaces (< 1 nm) and a composition amplitude close to 95% for the longer wavelength.

Measurement of magnetic domain wall width using energy-filtered Fresnel images

Magnetic domain walls in Nd2Fe14B have been examined using a series of energy-filtered Fresnel images in the field emission gun transmission electron microscope (FEGTEM). We describe the changes in the intensity distribution of the convergent wall image as a function of defocus, foil thickness and domain wall width. The effect of tilted domain walls and beam convergence on the fringe pattern is also discussed. A comparison of the experimental intensity profile with that from simulations allows the domain wall width to be determined. Measurement of very narrow walls is made possible only by using a relatively thick foil, which necessitates energy-filtering to allow quantitative comparison with simulations. The magnetic domain wall width in Nd2Fe14B was found to be 3 +/- 2 nm.

Effects of interlayer coupling on the irreversibility lines of NbN/AlN superconducting multilayers

We have studied the temperature dependence of the in-plane resistivity of NbN/AlN multilayer samples with varying insulating layer thickness in magnetic fields up to 7 T parallel and perpendicular to the films. The upper critical field shows a crossover from 2D to 3D behavior in parallel fields. The irreversibility lines have the form (1-T/T(c))(alpha), where alpha varies from 4 / 3 to 2 with increasing anisotropy. The results are consistent with simultaneous melting and decoupling transitions for the low anisotropy sample, and with melting of decoupled pancakes in the superconducting layers for higher anisotropy samples.

Spironolactone in the treatment of congestive heart failure

OBJECTIVE

To evaluate evidence supporting the use of spironolactone in managing congestive heart failure.

DATA SOURCES

Literature accessed through MEDLINE (January 1966-December 1999) and cross-referencing of selected articles. Search terms included spironolactone and heart failure.

DATA SYNTHESIS

Heart failure is a leading cause of morbidity and mortality. Through aldosterone antagonism, spironolactone may be an effective pharmacotherapeutic addition to patients not responding to standard drug therapy for heart failure.

RESULTS

Clinical trials have demonstrated that, in patients with heart failure, spironolactone improves laboratory indices, quality of life, and morbidity. Recently, spironolactone has been demonstrated to improve the survival of patients with New York Heart Association (NYHA) III or IV heart failure.

CONCLUSIONS

Spironolactone use should be considered in patients with NYHA Class III or IV heart failure.

The mechanism of aconitase: 1.8 A resolution crystal structure of the S642a:citrate complex

The crystal structure of the S642A mutant of mitochondrial aconitase (mAc) with citrate bound has been determined at 1.8 A resolution and 100 K to capture this binding mode of substrates to the native enzyme. The 2.0 A resolution, 100 K crystal structure of the S642A mutant with isocitrate binding provides a control, showing that the Ser --> Ala replacement does not alter the binding of substrates in the active site. The aconitase mechanism requires that the intermediate product, cis-aconitate, flip over by 180 degrees about the C alpha-C beta double bond. Only one of these two alternative modes of binding, that of the isocitrate mode, has been previously visualized. Now, however, the structure revealing the citrate mode of binding provides direct support for the proposed enzyme mechanism.

An unusual seat belt injury in a 7-year-old boy

A luxation injury of a lower primary incisor in a 7-year-old boy was caused by the shoulder component of a seat belt. This highlights the increased risk of injury in children who are too large for safety seats but still too small for adult seat belts.

Y13C Azotobacter vinelandii ferredoxin I. A designed [Fe-S] ligand motif contains a cysteine persulfide

Ferredoxins that contain [4Fe-4S]2+/+ clusters often obtain three of their four cysteine ligands from a highly conserved CysXXCysXXCys sequence motif. Little is known about the in vivo assembly of these clusters and the role that this sequence motif plays in that process. In this study, we have used structure as a guide in attempts to direct the formation of a [4Fe-4S]2+/+ in the [3Fe-4S]+/0 location of native (7Fe) Azotobacter vinelandii ferredoxin I (AvFdI) by providing the correct three-dimensional orientation of cysteine ligands without introducing a CysXXCysXXCys motif. Tyr13 of AvFdI occupies the position of the fourth ligating cysteine in the homologous and structurally characterized 8Fe ferredoxin from Peptococcus aerogenes and a Y13C variant of AvFdI could be easily modeled as an 8Fe protein. However, characterization of purified Y13C FdI by UV-visible spectra, circular dichroism, electron paramagnetic resonance spectroscopies, and by x-ray crystallography revealed that the protein failed to use the introduced cysteine as a ligand and retained its [3Fe-4S]+/0 cluster. Further, electrochemical characterization showed that the redox potential and pH behavior of the cluster were unaffected by the substitution of Tyr by Cys. Although Y13C FdI is functional in vivo it does differ significantly from native FdI in that it is extremely unstable in the reduced state possibly due to increased solvent exposure of the [3Fe-4S]0 cluster. Surprisingly, the x-ray structure showed that the introduced cysteine was modified to become a persulfide. This modification may have occurred in vivo via the action of NifS, which is known to be expressed under the growth conditions used. It is interesting to note that neither of the two free cysteines present in FdI was modified. Thus, if NifS is involved in modifying the introduced cysteine there must be specificity to the reaction.

The lymphatic circulation plays a dynamic role in blood volume and plasma protein restitution after hemorrhage

The purpose of this study was to determine the contribution of the lymphatic circulation to blood volume and plasma protein restitution after hemorrhage. Splenectomized sheep were prepared with thoracic duct and vascular catheters. The day after surgery, thoracic duct lymph flow, thoracic duct lymph protein, plasma protein, mean arterial pressure, and blood volume were measured. After 12 h, awake sheep were either bled 25% of blood volume over 5 min (HEM; n = 6) or observed (SHAM; n = 5) and measurements were recorded for 48 h. In HEM, the thoracic duct protein return rate and thoracic duct lymph flow transiently decreased (0-.5 h) but were then equal to or greater than that in SHAM. In HEM, there was restitution of both blood volume and plasma protein mass approximately 12 h after hemorrhage. Both thoracic duct lymph flow and protein return rate are significant contributors to blood volume and plasma protein restitution after hemorrhage. These findings and the prior demonstration by the authors that lymphatic vessel pumping is increased after hemorrhage suggest a dynamic role for the lymphatic circulation in blood volume homeostasis after hemorrhage.

Genetic identification of an autoinhibitor in CDPK, a protein kinase with a calmodulin-like domain

CDPKs are a family of calcium (Ca2+)-dependent protein kinases which are defined by a carboxyl-terminal calmodulin-like domain. Mutational analysis indicates that the junction domain, which joins the kinase and calmodulin-like domains, contains an autoinhibitor. CDPK isoform AK1 from Arabidopsis was expressed in Escherichia coli as a fusion protein sandwiched between glutathione S-transferase and six consecutive histidines at the N- and C-terminal ends, respectively. This fusion, called AK1-6H, was purified and displayed kinase activity which was stimulated up to 127-fold by Ca2+, with a typical specific activity of 2000 nmol min-1 mg-1, using syntide-2 as peptide substrate. A truncation which deletes the calmodulin-like domain, as in mutant delta C-6H, disrupts Ca2+ activation and leaves the enzyme with a basal level of activity. Delta C-6H could be activated 87-fold by preincubation with a purified polyclonal IgG which was raised against a junction domain fusion. A further deletion of the junction domain, as in mutant delta JC, results in a constitutively active enzyme. This indicates that the junction domain in delta C-6H can function as an autoinhibitor. Its function as an autoinhibitor in a full-length enzyme was confirmed by site-specific mutagenesis, as shown by mutant KJM23-6H, which had a six-residue substitution in the junction domain between A422 and A432. Both delta JC and KJM23-6H encoded Ca(2+)-independent enzymes which had specific activities greater than 70% that of a fully active AK1-6H and displayed equivalent Km values for ATP and syntide-2. Inhibition studies on delta JC, using peptides based on the autoinhibitory domains of Ca2+/calmodulin-dependent protein kinases, are consistent with a model where the junction domain contains a similar pseudosubstrate-type autoinhibitor.

Intrinsic pumping of mesenteric lymphatics is increased after hemorrhage in awake sheep

Lymphatic vessels have the ability to contract and transport liquid and protein from tissue spaces to the intravascular space. The purpose of this investigation was to test whether this lymph pump is stimulated following a fixed volume hemorrhage in awake sheep. To quantitate lymphatic pumping in vivo, a mesenteric lymphatic was isolated from all lymph input and provided with Krebs solution at a fixed transmural pressure. A branch of the mesenteric duct was cannulated to provide a measure of lymph flow rate. Each animal was either bled 25% of blood volume over 5 min or was observed. Systemic arterial blood pressure declined in all bled sheep (P < 0.05). Hemorrhage had no effect on lymph flow from mesenteric ducts. However, hemorrhage significantly enhanced lymphatic pumping, approximately 200% of control values 3 hr after hemorrhage (P < 0.01). Increased lymphatic pumping after hemorrhage may play an important role in blood volume and protein restitution.

Induction of alloxan/streptozotocin diabetes in dogs: a revised experimental technique

The diabetic dog represents an excellent model for use in many aspects of diabetic research. The present paper describes, in detail, a reproducible experimental protocol for the successful induction of chemical diabetes in beagles using a combination of the 2 pancreatic beta-cell cytoxic agents alloxan and streptozotocin.

Purification of choline acetyltransferase from the locust Schistocerca gregaria and production of serum antibodies to this enzyme

Choline acetyltransferase (ChAT; EC 2.3.1.6) was purified from the heads of Schistocerca gregaria to a final specific activity of 1.61 mumol acetylcholine (ACh) formed min-1 mg-1 protein. The molecular mass of the enzyme as determined by gel filtration is 66,800 daltons. The final enzyme preparation showed one major band at 65,000 daltons on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, which corresponds with the native molecular mass of the enzyme, a band at 56,000 daltons, and two bands at 40,500 and 38,000 daltons. Antibodies raised against ChAT in rabbit react only with the active band on native gel after Western blotting. They strongly react with the 65,000-dalton polypeptide band on Western blots of SDS gel separation of pure preparation of enzyme and with both the 65,000- and 56,000-dalton bands after SDS gel separation of crude extract.

Activation of the multifunctional Ca2+/calmodulin-dependent protein kinase by autophosphorylation: ATP modulates production of an autonomous enzyme

The multifunctional Ca2+/calmodulin-dependent protein kinase purified from rat brain cytosol undergoes an intramolecular self-phosphorylation or autophosphorylation. Autophosphorylation produces two strikingly different effects on kinase activity that are dependent on the level of ATP used in the reaction. At low but saturating levels of ATP (5 microM), autophosphorylation causes a 75% reduction in kinase activity, with the residual activity still retaining a dependence on Ca2+ and calmodulin. By contrast, at high but physiological levels of ATP (500 microM), the kinase is converted by autophosphorylation to a form that is autonomous of Ca2+ and calmodulin, with no accompanying reduction in activity. The extent of phosphate incorporation does not determine whether the kinase becomes inhibited or autonomous. Autophosphorylated kinase shows the functional change characteristic of the ATP concentration used during the reaction--inhibited at low ATP and autonomous at high ATP--even when compared at the same level of incorporated phosphate. ATP appears to regulate the site(s) phosphorylated during activation of the kinase and thereby modulates the dual effects of autophosphorylation. Events triggered by transient elevations of cellular Ca2+ may be potentiated and retained by generation of the Ca2+/calmodulin-independent protein kinase activity.

A possible circulating plasma factor in Duchenne muscular dystrophy

Basal (Na+, K+)AtPase activity was found to be significantly reduced in erythrocyte ghosts from patients with Duchenne muscular dystrophy, and, whereas ouabain inhibited enzyme activity in controls, it stimulated activity in patients. Prior incubation of normal erythrocyte ghosts in Duchenne plasma resulted in an increase in enzyme activity on subsequent exposure to ouabain. This suggests there may be a "circulating plasma factor" in Duchenne muscular dystrophy responsible for the abnormal response to ouabain. This "factor" was rendered inactive by dialysis or deproteination of the plasma.

Amenorrhea and galactorrhea: results of therapy with 2-Brom-alpha-ergocryptine (CB-154)

Administration of Brom-ergocryptine (CB-154) has a dramatic effect on breast secretion. Inhibition of lactation occurs within three to four weeks in women with amenorrhea and galactorrhea. Resumption of normal ovulatory function was documented by serum progesterone levels, as well as pregnancy, in three of four women attempting to conceive. Serum prolactin levels become normal following initiation of Brom-ergocryptine. Discontinuation of Brom-ergocryptine was found to result in a return of both inappropriate lactation and elevation of serum prolactin in this study. No deleterious side effects of Brom-ergocryptine have been found in any of the volunteers either clinically or on the basis of sequential laboratory studies.