Quantitation of ER Morphology and Dynamics

The plant endoplasmic reticulum forms a network of tubules connected by three-way junctions or sheet-like cisternae. Although the network is three-dimensional, in many plant cells, it is constrained to thin volume sandwiched between the vacuole and plasma membrane, effectively restricting it to a 2-D planar network. The structure of the network, and the morphology of the tubules and cisternae can be automatically extracted following intensity-independent edge-enhancement and various segmentation techniques to give an initial pixel-based skeleton, which is then converted to a graph representation. ER dynamics can be determined using optical flow techniques from computer vision or persistency analysis. Collectively, this approach yields a wealth of quantitative metrics for ER structure and can be used to describe the effects of pharmacological treatments or genetic manipulation. The software is publicly available.

Long-Term Imaging of Endoplasmic Reticulum Morphology in Embryos During Seed Germination

Imaging plant embryos at the cellular level over time is technically challenging, since the embryo, once its protective seed coat is removed, must be kept viable and unstressed on a microscope slide for the duration of the experiment. Here we describe a procedure and suitable apparatus for the visualization, over several days, of changes in endoplasmic reticulum (ER) morphology associated with the process of germination in Arabidopsis thaliana seeds. Moreover, we also present a user-friendly image analysis tool, which enables subtle perturbations in the ER network to be measured.

A tell tail sign: a conserved C-terminal tail-anchor domain targets a subset of pathogen effectors to the plant endoplasmic reticulum

The endoplasmic reticulum (ER) is the entry point to the secretory pathway and, as such, is critical for adaptive responses to biotic stress, when the demand for de novo synthesis of immunity-related proteins and signalling components increases significantly. Successful phytopathogens have evolved an arsenal of small effector proteins which collectively reconfigure multiple host components and signalling pathways to promote virulence; a small, but important, subset of which are targeted to the endomembrane system including the ER. We identified and validated a conserved C-terminal tail-anchor motif in a set of pathogen effectors known to localize to the ER from the oomycetes Hyaloperonospora arabidopsidis and Plasmopara halstedii (downy mildew of Arabidopsis and sunflower, respectively) and used this protein topology to develop a bioinformatic pipeline to identify putative ER-localized effectors within the effectorome of the related oomycete, Phytophthora infestans, the causal agent of potato late blight. Many of the identified P. infestans tail-anchor effectors converged on ER-localized NAC transcription factors, indicating that this family is a critical host target for multiple pathogens.

Chloroplasts play a central role in facilitating MAMP-triggered immunity, pathogen suppression of immunity and crosstalk with abiotic stress

Microbe-associated molecular pattern (MAMP)-triggered immunity (MTI) research has traditionally centred around signal transduction pathways originating from activated membrane-localized pattern recognition receptors (PRRs), culminating in nuclear transcription and posttranslational modifications. More recently, chloroplasts have emerged as key immune signalling hubs, playing a central role in integrating environmental signals. Notably, MAMP recognition induces chloroplastic reactive oxygen species (cROS) that is suppressed by pathogen effectors, which also modify the balance of chloroplast-synthesized precursors of the defence hormones, jasmonic acid, salicylic acid (SA) and abscisic acid. This study focuses on how well-characterized PRRs and coreceptors modulate chloroplast physiology, examining whether diverse signalling pathways converge to similarly modulate chloroplast function. Pretreatment of receptor mutant plants with MAMP and D(Damage)AMP peptides usually protect against effector modulation of chlorophyll fluorescence and prevent Pseudomonas syringae effector-mediated quenching of cROS and suppression of maximum dark-adapted quantum efficiency (the ratio of variable/maximum fluorescence [F_v /F_m ]). The MTI coreceptor double mutant, bak1-5/bkk1-1, exhibits a remarkable decrease in F_v /F_m compared to control plants during infection, underlining the importance of MTI-mediated signalling in chloroplast immunity. Further probing the role of the chloroplast in immunity, we unexpectedly found that even moderate changes in light intensity can uncouple plant immune signalling.

The Passage of H2O2 from Chloroplasts to Their Associated Nucleus during Retrograde Signalling: Reflections on the Role of the Nuclear Envelope

The response of chloroplasts to adverse environmental cues, principally increases in light intensity, stimulates chloroplast-to-nucleus retrograde signalling, which leads to the induction of immediate protective responses and longer-term acclimation. Hydrogen peroxide (H₂O₂), generated during photosynthesis, is proposed to both initiate and transduce a retrograde signal in response to photoinhibitory light intensities. Signalling specificity achieved by chloroplast-sourced H₂O₂ for signal transduction may be dependent upon the oft-observed close association of a proportion of these organelles with the nucleus. In this review, we consider more precisely the nature of the close association between a chloroplast appressed to the nucleus and the requirement for H₂O₂ to cross both the double membranes of the chloroplast and nuclear envelopes. Of particular relevance is that the endoplasmic reticulum (ER) has close physical contact with chloroplasts and is contiguous with the nuclear envelope. Therefore, the perinuclear space, which transducing H₂O₂ molecules would have to cross, may have an oxidising environment the same as the ER lumen. Based on studies in animal cells, the ER lumen may be a significant source of H₂O₂ in plant cells arising from the oxidative folding of proteins. If this is the case, then there is potential for the ER lumen/perinuclear space to be an important location to modify chloroplast-to-nucleus H₂O₂ signal transduction and thereby introduce modulation of it by additional different environmental cues. These would include for example, heat stress and pathogen infection, which induce the unfolded protein response characterised by an increased H₂O₂ level in the ER lumen.

Analysis of the impact of indole-3-acetic acid (IAA) on gene expression during leaf senescence in Arabidopsis thaliana

Leaf senescence is an important developmental process for the plant life cycle. It is controlled by endogenous and environmental factors and can be positively or negatively affected by plant growth regulators. It is characterised by major and significant changes in the patterns of gene expression. Auxin, especially indole-3-acetic acid (IAA), is a plant growth hormone that affects plant growth and development. The effect of IAA on leaf senescence is still unclear. In this study, we performed microarray analysis to investigate the role of IAA on gene expression during senescence in Arabidopsis thaliana. We sprayed IAA on plants at 3 different time points (27, 31 or 35 days after sowing). Following spraying, PSII activity of the eighth leaf was evaluated daily by measurement of chlorophyll fluorescence parameters. Our results show that PSII activity decreased following IAA application and the IAA treatment triggered different gene expression responses in leaves of different ages.

Arabidopsis Lunapark proteins are involved in ER cisternae formation

The plant endoplasmic reticulum (ER) is crucial to the maintenance of cellular homeostasis. The ER consists of a dynamic and continuously remodelling network of tubules and cisternae. Several conserved membrane proteins have been implicated in formation and maintenance of the ER network in plants, such as RHD3 and the reticulon proteins. Despite the recent work in mammalian and yeast cells, the detailed molecular mechanisms of ER network organization in plants remain largely unknown. Recently, novel ER network-shaping proteins called Lunapark (LNP) have been identified in yeast and mammalian cells. Here we identify two Arabidopsis LNP homologues and investigate their subcellular localization via confocal microscopy and potential function in shaping the ER network using protein-protein interaction assays and mutant analysis. We show that AtLNP1 overexpression in tobacco leaf epidermal cells mainly labels cisternae in the ER network, whereas AtLNP2 labels the whole ER. Overexpression of LNP proteins results in an increased abundance of ER cisternae and lnp1 and lnp1lnp2 amiRNA lines display a reduction in cisternae and larger polygonal areas. Thus, we hypothesize that AtLNP1 and AtLNP2 are involved in determining the network morphology of the plant ER, possibly by regulating the formation of ER cisternae.

A C-terminal amphipathic helix is necessary for the in vivo tubule-shaping function of a plant reticulon

Reticulons (RTNs) are a class of endoplasmic reticulum (ER) membrane proteins that are capable of maintaining high membrane curvature, thus helping shape the ER membrane into tubules. The mechanism of action of RTNs is hypothesized to be a combination of wedging, resulting from the transmembrane topology of their conserved reticulon homology domain, and scaffolding, arising from the ability of RTNs to form low-mobility homo-oligomers within the membrane. We studied the plant RTN isoform RTN13, which has previously been shown to locate to ER tubules and the edges of ER cisternae and to induce constrictions in ER tubules when overexpressed, and identified a region in the C terminus containing a putative amphipathic helix (APH). Here we show that deletion of this region or disruption of the hydrophobic face of the predicted helix abolishes the ability of RTN13 to induce constrictions of ER tubules in vivo. These mutants, however, still retain their ability to interact and form low-mobility oligomers in the ER membrane. Hence, our evidence indicates that the conserved APH is a key structural feature for RTN13 function in vivo, and we propose that RTN, like other membrane morphogens, rely on APHs for their function.

A local regulatory network around three NAC transcription factors in stress responses and senescence in Arabidopsis leaves

A model is presented describing the gene regulatory network surrounding three similar NAC transcription factors that have roles in Arabidopsis leaf senescence and stress responses. ANAC019, ANAC055 and ANAC072 belong to the same clade of NAC domain genes and have overlapping expression patterns. A combination of promoter DNA/protein interactions identified using yeast 1-hybrid analysis and modelling using gene expression time course data has been applied to predict the regulatory network upstream of these genes. Similarities and divergence in regulation during a variety of stress responses are predicted by different combinations of upstream transcription factors binding and also by the modelling. Mutant analysis with potential upstream genes was used to test and confirm some of the predicted interactions. Gene expression analysis in mutants of ANAC019 and ANAC055 at different times during leaf senescence has revealed a distinctly different role for each of these genes. Yeast 1-hybrid analysis is shown to be a valuable tool that can distinguish clades of binding proteins and be used to test and quantify protein binding to predicted promoter motifs.

Arabidopsis defense against Botrytis cinerea: chronology and regulation deciphered by high-resolution temporal transcriptomic analysis

Transcriptional reprogramming forms a major part of a plant's response to pathogen infection. Many individual components and pathways operating during plant defense have been identified, but our knowledge of how these different components interact is still rudimentary. We generated a high-resolution time series of gene expression profiles from a single Arabidopsis thaliana leaf during infection by the necrotrophic fungal pathogen Botrytis cinerea. Approximately one-third of the Arabidopsis genome is differentially expressed during the first 48 h after infection, with the majority of changes in gene expression occurring before significant lesion development. We used computational tools to obtain a detailed chronology of the defense response against B. cinerea, highlighting the times at which signaling and metabolic processes change, and identify transcription factor families operating at different times after infection. Motif enrichment and network inference predicted regulatory interactions, and testing of one such prediction identified a role for TGA3 in defense against necrotrophic pathogens. These data provide an unprecedented level of detail about transcriptional changes during a defense response and are suited to systems biology analyses to generate predictive models of the gene regulatory networks mediating the Arabidopsis response to B. cinerea.

High-resolution temporal profiling of transcripts during Arabidopsis leaf senescence reveals a distinct chronology of processes and regulation

Leaf senescence is an essential developmental process that impacts dramatically on crop yields and involves altered regulation of thousands of genes and many metabolic and signaling pathways, resulting in major changes in the leaf. The regulation of senescence is complex, and although senescence regulatory genes have been characterized, there is little information on how these function in the global control of the process. We used microarray analysis to obtain a high-resolution time-course profile of gene expression during development of a single leaf over a 3-week period to senescence. A complex experimental design approach and a combination of methods were used to extract high-quality replicated data and to identify differentially expressed genes. The multiple time points enable the use of highly informative clustering to reveal distinct time points at which signaling and metabolic pathways change. Analysis of motif enrichment, as well as comparison of transcription factor (TF) families showing altered expression over the time course, identify clear groups of TFs active at different stages of leaf development and senescence. These data enable connection of metabolic processes, signaling pathways, and specific TF activity, which will underpin the development of network models to elucidate the process of senescence.

A specific group of genes respond to cold dehydration stress in cut Alstroemeria flowers whereas ambient dehydration stress accelerates developmental senescence expression patterns

Petal development and senescence entails a normally irreversible process. It starts with petal expansion and pigment production, and ends with nutrient remobilization and ultimately cell death. In many species this is accompanied by petal abscission. Post-harvest stress is an important factor in limiting petal longevity in cut flowers and accelerates some of the processes of senescence such as petal wilting and abscission. However, some of the effects of moderate stress in young flowers are reversible with appropriate treatments. Transcriptomic studies have shown that distinct gene sets are expressed during petal development and senescence. Despite this, the overlap in gene expression between developmental and stress-induced senescence in petals has not been fully investigated in any species. Here a custom-made cDNA microarray from Alstroemeria petals was used to investigate the overlap in gene expression between developmental changes (bud to first sign of senescence) and typical post-harvest stress treatments. Young flowers were stressed by cold or ambient temperatures without water followed by a recovery and rehydration period. Stressed flowers were still at the bud stage after stress treatments. Microarray analysis showed that ambient dehydration stress accelerates many of the changes in gene expression patterns that would normally occur during developmental senescence. However, a higher proportion of gene expression changes in response to cold stress were specific to this stimulus and not senescence related. The expression of 21 transcription factors was characterized, showing that overlapping sets of regulatory genes are activated during developmental senescence and by different stresses.

Socioeconomic differences in physical disability at older age

BACKGROUND

This study aims to investigate the association between socioeconomic position (SEP) and physical disability at older age, using a framework that incorporates education, social class and wealth. Wave One data from the English Longitudinal Study of Ageing are used.

METHODS

Self-reported difficulties with activities of daily living, instrumental activities of daily living and motor skills were combined and categorised into "no disability", "mild disability" and "severe disability". The indicators of SEP used were wealth, education and social class. Multinomial regression was used to assess the associations between SEP and physical functioning reflecting the temporal relationship between education, social class and wealth.

RESULTS

Men and women who had the highest levels of wealth, education and social class also had the lowest disability rates. The association was stronger in younger age groups and in men. The association of education with disability, which was found to be significant in the unadjusted models, was attenuated when adjusted for other factors such as occupation or wealth. This supports a temporal model of education feeding into occupation and then wealth. The association of SEP with disability was stronger for men and for men and women in the younger age group.

CONCLUSIONS

Socioeconomic circumstances affect the prevalence and scale of physical disability even at older ages. In particular, wealth appears more important as a socioeconomic factor for physical disability than social class or education. Socioeconomic gradients in physical disability are greater for men than for women and for those in the younger age groups.

Cardiorespiratory risk factors as predictors of 40-year mortality in women and men

OBJECTIVE

Most historical studies of cardiorespiratory risk factors as predictors of mortality have been based on men. This study examines whether they predict mortality over long periods in women and men.

DESIGN

Prospective cohort study.

SETTING

Participants were employees of the General Post Office.

METHODS

Risk factor data were collected via clinical examination and questionnaire, 1966-7. Associations between cardiorespiratory risk factors and 40-year mortality were determined for 644 women and 1272 men aged 35-70 at examination.

MAIN OUTCOME MEASURES

All-cause, cardiovascular (CVD), cancer and respiratory mortality.

RESULTS

Associations between systolic blood pressure and all-cause and stroke mortality were equally strong for women and men, hazard ratio (95% confidence interval) 1.25 (1.1 to 1.4) and 1.18 (1.1 to 1.3); and 2.17 (1.7 to 2.8) and 1.69 (1.4 to 2.1), respectively. Cholesterol was higher in women and was associated with all-cause 1.22 (1.1 to 1.4) and CVD 1.39 (1.2 to 1.7) mortality, while associations between 2-hour glucose and all-cause 1.15 (1.1 to 1.2), coronary heart disease (CHD) 1.25 (1.1 to 1.4) and respiratory mortality 1.21 (1.0 to 1.5) were observed in men. Obesity was associated with stroke in women (2.42 (1.12 to 5.24)) and CHD in men (1.59 (1.02 to 2.49)), while ECG ischaemia was associated with CVD in both sexes. The strongest, most consistent predictor of mortality was smoking in women and poor lung function in men. However, evidence of sex differences in associations between the cardiorespiratory risk factors measured and mortality was sparse.

CONCLUSIONS

Data from a 40-year follow-up period show remarkably persistent associations between risk factors and cardiorespiratory and all-cause mortality in women and men.

Transcriptional regulation of plant senescence: from functional genomics to systems biology

Leaf senescence is an active process that involves the increased expression of many hundreds of genes. Many putative transcription factors show enhanced transcription during leaf senescence in Arabidopsis and functional analysis of these should help to indicate their role in controlling gene expression during leaf senescence. In this paper, we describe the analysis of knockout insertion mutants in two different senescence-enhanced genes, one encodes a heat shock transcription factor and the other a zinc finger protein. Plants mutated in these genes show accelerated leaf senescence and reduced tolerance to drought stress, indicating that expression of these genes during senescence has a protective role to maintain viability during this essential developmental process. Analysis of gene expression changes in both mutants compared to the wild-type plants indicates an increased rate of senescence but does not show clearly the pathway that is dependent on these genes for expression. The complexities of signalling networks in plant stress and the plasticity of plant responses mean that the direct consequences of mutation are very difficult to define. The usefulness of this type of approach to address the burning question of how senescence is regulated is discussed, and an alternative approach aimed at a more global analysis of gene regulation using systems biology methods is described.

Overexpression of a chromatin architecture-controlling AT-hook protein extends leaf longevity and increases the post-harvest storage life of plants

Leaf senescence is the final stage of leaf development and is finely regulated via a complex genetic regulatory network incorporating both developmental and environmental factors. In an effort to identify negative regulators of leaf senescence, we screened activation-tagged Arabidopsis lines for mutants that exhibit a delayed leaf senescence phenotype. One of the mutants (ore7-1D) showed a highly significant delay of leaf senescence in the heterozygous state, leading to at least a twofold increase in leaf longevity. The activated gene (ORE7/ESC) encoded a protein with an AT-hook DNA-binding motif; such proteins are known to co-regulate transcription of genes through modification of chromatin architecture. We showed that ORE7/ESC, in addition to binding to a plant AT-rich DNA fragment, could also modify the chromatin architecture, as illustrated by an altered distribution of a histone-GFP fusion protein in the nucleus of the mutant. Globally altered gene expression, shown by microarray analysis, also indicated that activation of ORE7/ESC results in a younger condition in the mutant leaves. We propose that ectopically expressed ORE7/ESC is negatively regulating leaf senescence and suggest that the resulting chromatin alteration may have a role in controlling leaf longevity. Interestingly, activation of ORE7/ESC also led to a highly extended post-harvest storage life.

Socioeconomic gradients in cardiorespiratory disease and diabetes in the 1960s: baseline findings from the GPO study

OBJECTIVES

To describe the socioeconomic distribution of risk factors for cardiorespiratory disease and diabetes in employed women and men in the late 1960s.

STUDY DESIGN AND METHODS

Cross-sectional data were collected from 3345 General Post Office (GPO) employees in London, via a questionnaire and clinical examination, between October 1966 and April 1967.

RESULTS

Our occupational grade classification conformed to expected patterns of greater car ownership and gardening among higher-grade women and men, and greater height in higher-grade men (highest-lowest grade 175.0-170.7 cm, P<0.001). A strong inverse grade gradient in bronchitis (2.1-9.4%, P<0.001) and a strong positive gradient in FEV1 (3.10-2.58l, P<0.001) were observed in men, although smoking was less consistently associated with grade. There was no consistent inverse association between grade and any cardiovascular risk factor in either sex, but strong inverse gradients in prevalence of impaired glucose tolerance (IGT) (5.1-18.2%, P<0.001) and 2-h glucose (4.14-4.25 mmol/l, P<0.001) in non-diabetic men. Using car ownership as an alternative measure of socioeconomic position, findings in men were replicated for respiratory measures, IGT and 2-h glucose prevalence. Inverse gradients were additionally observed for blood pressure, cholesterol and electrocardiogram abnormalities.

CONCLUSIONS

The GPO study confirms existing evidence of socioeconomic gradients in respiratory risk factors and provides new evidence of gradients in risk factors for diabetes in men. Although there was no conclusive evidence of an occupational gradient in any cardiovascular risk factor, car ownership was a good indicator of lower risk in men. No socioeconomic gradients in cardiorespiratory or diabetic risk factors were observed in women.

Obesity and overweight in relation to disease-specific mortality in men with and without existing coronary heart disease in London: the original Whitehall study

OBJECTIVE

To examine the relations between obesity or overweight and coronary heart disease (CHD) mortality in men with and without prevalent CHD in a prospective cohort study.

METHODS

In the Whitehall study of London-based male government employees, 18 403 middle age men were followed up for a maximum of 35 years having participated in a medical examination in the late 1960s in which weight, height, CHD status, and a range of other social, physiological, and behavioural characteristics were measured.

RESULTS

In age-adjusted analyses of men with baseline CHD there was a modest raised risk in the overweight relative to normal weight groups for all cause mortality (hazard ratio 1.10, 95% confidence interval (CI) 1.00 to 1.20) and CHD mortality (1.28, 95% CI 1.11 to 1.47) but not for stroke mortality (1.01, 95% CI 0.73 to 1.40). Mortality was similarly raised in the obese group. While these slopes were much steeper in men who were apparently CHD-free at study induction, the difference in the gradients according to baseline CHD status did not attain significance at conventional levels (p value for interaction >or= 0.24). The weight-mortality relations were somewhat attenuated when potential mediating and confounding factors were added to the multivariable models in both men with and men without a history of CHD.

CONCLUSIONS

Avoidance of obesity and overweight in adult life in men with and without CHD may reduce their later risk of total and CHD mortality.

Obesity and overweight in relation to organ-specific cancer mortality in London (UK): findings from the original Whitehall study

OBJECTIVE

To examine the relation of obesity and overweight with organ-specific cancer mortality.

METHODS

In the Whitehall prospective cohort study of London-based government employees, 18 403 middle-age men participated in a medical examination between 1967 and 1970. Subjects were followed up for cause-specific mortality for up to 35 y (median: interquartile range (25th-75th centile); 28.1 y: 18.6-33.8).

RESULTS

There were over 3000 cancer deaths in this cohort. There was a raised risk of mortality from carcinoma of the rectum, bladder, colon, and liver, and for lymphoma in obese or overweight men following adjustment for range of covariates, which included socioeconomic position and physical activity. These relationships held after exclusion of deaths occurring in the first 20 y of follow-up.

CONCLUSION

Avoidance of obesity and overweight in adult life may reduce the risk of developing some cancers.

Comparative transcriptome analysis reveals significant differences in gene expression and signalling pathways between developmental and dark/starvation-induced senescence in Arabidopsis

An analysis of changes in global gene expression patterns during developmental leaf senescence in Arabidopsis has identified more than 800 genes that show a reproducible increase in transcript abundance. This extensive change illustrates the dramatic alterations in cell metabolism that underpin the developmental transition from a photosynthetically active leaf to a senescing organ which functions as a source of mobilizable nutrients. Comparison of changes in gene expression patterns during natural leaf senescence with those identified, when senescence is artificially induced in leaves induced to senesce by darkness or during sucrose starvation-induced senescence in cell suspension cultures, has shown not only similarities but also considerable differences. The data suggest that alternative pathways for essential metabolic processes such as nitrogen mobilization are used in different senescent systems. Gene expression patterns in the senescent cell suspension cultures are more similar to those for dark-induced senescence and this may be a consequence of sugar starvation in both tissues. Gene expression analysis in senescing leaves of plant lines defective in signalling pathways involving salicylic acid (SA), jasmonic acid (JA) and ethylene has shown that these three pathways are all required for expression of many genes during developmental senescence. The JA/ethylene pathways also appear to operate in regulating gene expression in dark-induced and cell suspension senescence whereas the SA pathway is not involved. The importance of the SA pathway in the senescence process is illustrated by the discovery that developmental leaf senescence, but not dark-induced senescence, is delayed in plants defective in the SA pathway.

Socioeconomic differences in the prevalence of common chronic diseases: an overview of eight European countries

BACKGROUND

Few studies have compared socioeconomic inequalities in the prevalence of both fatal and non-fatal diseases. This paper aims to give the first international overview for several common chronic diseases.

METHODS

Micro-level data were pooled from non-standardized national health surveys conducted in eight European countries in the 1990s. Surveys ranged in size from 3700 to 41 200 participants. The prevalence of 17 chronic disease groups were analysed in relation to education. Standardized prevalence rates and age-adjusted odds ratios (ORs) were calculated.

RESULTS

Most diseases showed higher prevalence among the lower education group. Stroke, diseases of the nervous system, diabetes, and arthritis displayed relatively large inequalities (OR > 1.50). No socioeconomic differences were evident for cancer, kidney diseases, and skin diseases. Allergy was more common in the higher education group. Relative socioeconomic differences were often smaller among the 60-79 age group as compared with the 25-59 age group. Cancer was more prevalent among the lower educated in the 25-59 age group, but among the higher educated in the 60-79 age group. For diabetes, hypertension, and heart disease, socioeconomic differences were larger among women as compared with men. Inequalities in heart disease were larger in northern European countries as compared with southern European countries.

CONCLUSION

There are large variations between chronic diseases in the size and pattern of socioeconomic differences in their prevalence. The large inequalities that are found for some specific fatal diseases (e.g. stroke) and non-fatal diseases (e.g. arthritis) require special attention in equity-oriented research and policies.

Area deprivation, social class, and quality of life among people aged 75 years and over in Britain

BACKGROUND

There is a shortage of research studies that assess how selected characteristics of neighbourhood and personal social circumstances contribute towards health-related quality of life (QoL) among older people.

METHODS

Analysis of baseline data for 5581 people aged > or =75 years and over from the Trial of Assessment and Management of Older People in the Community. The scores for four dimensions from the UK version of the Sickness Impact Profile and for the Philadelphia Geriatric Morale Scale were analysed in relation to individual social class and the Carstairs score of socioeconomic deprivation for the enumeration district of residence.

RESULTS

In age and sex adjusted analyses, the proportion of participants of social class IV/V living in the most deprived areas who were in the quintile with worst QoL scores was more than double that among those from social class I/II living in the least deprived areas. Individual social class and area deprivation score contributed roughly equally to this doubling for home management, self-care and social interaction, whereas social class appeared a stronger determinant for mobility. Adjustment for living circumstances, health symptoms, and health behaviours substantially reduced the excess risk associated with social class and area deprivation. Being in a rural area was associated with lower risk of poor morale.

CONCLUSION

Poor socioeconomic characteristics of both the area and the individual are associated with worse functioning (QoL) of older people in the community. This is not fully explained by health status. Policy should consider community-level interventions as well as those directed at individuals.

Gene expression patterns to define stages of post-harvest senescence in Alstroemeria petals

Petal senescence in many species is regulated by ethylene but some flowers, such as those on the monocotyledonous plant Alstroemeria, var. Rebecca are ethylene insensitive. Changes in gene expression during the post-harvest senescence of Alstroemeria flowers were investigated using several different techniques. Suppressive subtractive hybridization (SSH) was used to obtain cDNA libraries enriched for genes expressed at selected stages of petal senescence. Sequencing of the EST clones obtained resulted in over 1000 sequences that represent approximately 500 different genes. Analysis of the potential functions of these genes provides a snapshot of the processes that are taking place during petal development. Both cell wall related genes and genes involved in metabolism were present at a higher proportion in the earlier stages. Genes encoding metal binding proteins (mostly metallothionein-like) were the major component of senescence enhanced libraries. This limited the diversity of genes identified showing differential expression at the later stages. Changes in the expression of all genes were analysed using microarray hybridization, and genes showing either up or down-regulation were identified. The expression pattern of a selection of genes was confirmed using Northern hybridization. Northern hybridization confirmed the up-regulation of metallothioneins after floral opening, however, this was not detected by the microarray analysis, indicating the importance of using a combination of methods to investigate gene expression patterns. Considerably more genes were up-regulated than down-regulated. This may reflect the need during Alstroemeria petal senescence for the expression of a whole new set of genes involved with degradation and mobilization. The potential uses of expression profiling to improve floral quality in breeding programmes or as a diagnostic tool are discussed.

Vitamin B12 and folate deficiency in later life

OBJECTIVES

to examine the prevalence of vitamin B12 deficiency and folate deficiency in later life in representative samples of the elderly population in the United Kingdom.

DESIGN

a population-based cross-sectional analysis of 3,511 people aged 65 years or older from three studies was used to estimate the age-specific prevalence of vitamin B12 deficiency and of folate deficiency. Vitamin B12 deficiency is conventionally diagnosed if serum vitamin B12 < 150 pmol/l ('low vitamin B12'). We defined 'metabolically significant vitamin B12 deficiency' as vitamin B12 < 200 pmol/l and blood total homocysteine >20 micro mol/l. Folate deficiency, which usually refers to serum folate <5 nmol/l, was defined as 'metabolically significant' if serum folate was <7 nmol/l and homocysteine >20 micro mol/l.

RESULTS

the prevalence of vitamin B12 deficiency, whether defined as low vitamin B12 or metabolically significant vitamin B12 deficiency increased with age in all three studies, from about 1 in 20 among people aged 65-74 years to 1 in 10 or even greater among people aged 75 years or greater. The prevalence of folate deficiency also increased with age, and was similar to that for vitamin B12 deficiencies, but only about 10% of people with low vitamin B12 levels also had low folate levels.

CONCLUSION

the high prevalence of vitamin B12 and folate deficiency observed in older people indicates a particular need for vigilance for deficiency of these vitamins. Reliable detection and treatment of vitamin deficiency could reduce the risk of deficiency-related disability in old age.

Prevalence of visual impairment in people aged 75 years and older in Britain: results from the MRC trial of assessment and management of older people in the community

AIMS

To measure the prevalence of visual impairment in a large representative sample of people aged 75 years and over participating in the MRC trial of assessment and management of older people in the community.

METHODS

53 practices in the MRC general practice research framework. Data were obtained from 14 600 participants aged 75 years and older. Prevalence of visual impairment overall (binocular visual acuity <6/18) which was categorised separately into low vision (binocular visual acuity <6/18-3/60) or blindness (binocular visual acuity of <3/60). The prevalence of binocular acuity <6/12 was presented for comparison with other studies. Visual acuity was measured using Glasgow acuity charts; glasses, if worn, were not removed.

RESULTS

Visual acuity was available for 14 600 people out of 21 241 invited (69%). Among people with visual acuity data, 12.4% overall (1803) were visually impaired (95% confidence intervals 10.8% to 13.9%); 1501 (10.3%) were categorised as having low vision (8.7% to 11.8%), and 302 (2.1%) were blind (1.8% to 2.4%). At ages 75-79, 6.2% of the cohort were visually impaired (5.1% to 7.3%) with 36.9% at age 90+ (32.5% to 41.3%). At ages 75-79, 0.6% (0.4% to 0.8%) of the study population were blind, with 6.9% (4.8% to 9.0%) at age 90+. In multivariate regression, controlling for age, women had significant excess risk of visual impairment (odds ratio 1.43, 95% confidence interval 1.29 to 1.58). Overall, 19.9% of study participants had a binocular acuity of less than 6/12 (17.8% to 22.0%).

CONCLUSION

The results from this large study show that visual impairment is common in the older population and that this risk increases rapidly with advancing age, especially for women. A relatively conservative measure of visual impairment was used. If visual impairment had been defined as visual acuity of <6/12 (American definition of visual impairment), the age specific prevalence estimates would have increased by 60%.

Randomised comparison of three methods of administering a screening questionnaire to elderly people: findings from the MRC trial of the assessment and management of older people in the community

OBJECTIVE

To compare three different methods of administering a brief screening questionnaire to elderly people: post, interview by lay interviewer, and interview by nurse.

DESIGN

Randomised comparison of methods within a cluster randomised trial.

SETTING

106 general practices in the United Kingdom.

PARTICIPANTS

32 990 people aged 75 years or over registered with participating practices.

MAIN OUTCOME MEASURES

Response rates, proportion of missing values, prevalence of self reported morbidity, and sensitivity and specificity of self reported measures by method of administration of questionnaire for four domains.

RESULTS

The response rate was higher for the postal questionnaire than for the two interview methods combined (83.5% v 74.9%; difference 8.5%, 95% confidence interval 4.4% to 12.7%, P<0.001). The proportion of missing or invalid responses was low overall (mean 2.1%) but was greater for the postal method than for the interview methods combined (4.1% v 0.9%; difference 3.2%, 2.7% to 3.6%, P<0.001). With a few exceptions, levels of self reported morbidity were lower in the interview groups, particularly for interviews by nurses. The sensitivity of the self reported measures was lower in the nurse interview group for three out of four domains, but 95% confidence intervals for the estimates overlapped. Specificity of the self reported measures varied little by method of administration.

CONCLUSIONS

Postal questionnaires were associated with higher response rates but also higher proportions of missing values than were interview methods. Lower estimates of self reported morbidity were obtained with the nurse interview method and to a lesser extent with the lay interview method than with postal questionnaires.

Comparison of quality of life and cough on eprosartan and enalapril in people with moderate hypertension

The objective of this study was to compare quality of life and incidence of dry persistent cough among patients treated with eprosartan and enalapril for mild-moderate hypertension. This was a randomised 26-week double-blind controlled trial carried out in clinics in nine countries of North America, Europe and South Africa. A total of 529 patients aged 18 and over with diastolic blood pressure between 95 mm Hg and 114 mm Hg were studied. Treatment comprised of eprosartan or enalapril monotherapy for 12 weeks with the option of hydrochlorothiazide addition for the remaining 14 weeks. The primary outcome measures were cough and the Psychological General Wellbeing Index (PGWB) total and subscales (anxiety, self-control, depression, general health, positive wellbeing and vitality). The results were that 17.8% of enalapril patients and 13.2% of eprosartan patients withdrew from randomised treatment. Those on enalapril were twice as likely to have gained a definite or possible cough by study end point as those on eprosartan (7.6% vs 3.2%) P = 0.099. At monotherapy end point the differences were greater (9.9% vs 2.1%) and of statistical significance, P = 0.001. Patients treated with enalapril, however, had small but significant improvements in measures of self-control and total PGWB compared with those on eprosartan. The effect sizes of 0.2 or less indicated that there were small differences. In conclusion eprosartan was associated with fewer coughs than enalapril but it performed less well on some aspects of quality of life.

Quality of life and cough on antihypertensive treatment: a randomised trial of eprosartan, enalapril and placebo

The objective of this study was to compare the quality of life and incidence of dry cough with the angiotensin II antagonist eprosartan, the ACE-inhibitor enalapril, and placebo, in hypertensive patients with a history of ACE-inhibitor cough. The study was a multicentre, randomised, double-blind, parallel group controlled trial. A total of 136 patients judged to have ACE-inhibitor cough during single-blind enalapril treatment which was lost during a subsequent placebo washout phase, were randomised to receive either eprosartan 300 mg twice daily, or enalapril 20 mg once daily, or placebo for 6 weeks. Self-completion questionnaires assessing quality of life and cough were examined at baseline and end of study. At study end point 23% of patients in the enalapril group and 5% in the eprosartan and placebo groups reported cough (which included definite, probable and possible coughs) (P = 0.02). After adjusting for multiple comparisons, the eprosartan group was not significantly different from either placebo or enalapril. There were no significant differences in the Psychological General Wellbeing Index (PGWB). In conclusion the incidence of self-reported cough on eprosartan was similar to that on placebo, and lower than on enalapril but this difference was not significant when adjustments were made for multiple comparisons. There were no differences in quality of life.

Do socioeconomic disadvantages persist into old age? Self-reported morbidity in a 29-year follow-up of the Whitehall Study

OBJECTIVES

This study examined (1) the relation of employment grade in middle age to self-reported poor health and functional limitations in old age and (2) whether socioeconomic status at approximately the time of retirement modifies health differentials in old age.

METHODS

Survivors of the Whitehall Study cohort of men were resurveyed. Respondents were aged 40 to 69 years when they were originally screened in 1967 to 1970.

RESULTS

Compared with senior administrators, men in clerical or manual (low-grade) jobs in middle age had quadruple the odds of poor physical performance in old age, triple the odds of poor general health, and double the odds of poor mental health and disability. At most, 20% of these differences were explained by baseline health or risk factors. Men who moved from low to middle grades before retirement were less likely than those who remained in low grades to have poor mental health.

CONCLUSIONS

Socioeconomic status in middle age and at approximately retirement age is associated with morbidity in old age.

Re-survey of the Whitehall study of London civil servants: changes in risk factors for cardiovascular disease during 29 years of follow-up

BACKGROUND

Substantial uncertainty persists about the relevance of blood pressure and cholesterol to the risk of cardiovascular disease in the elderly.

OBJECTIVE

To investigate the determinants of cardiovascular risk in old age, and the relevance of such risk factors when recorded in middle and old age.

METHODS

A re-survey in 1997 of 8537 survivors of a cohort of men who were originally examined in 1967-1970 when aged 40-69 years.

RESULTS

Completed questionnaires were received from 7050 (82%) of the survivors, and blood pressure and blood samples from 5427 (64%). The response rate declined with increasing age, was inversely related to markers of socioeconomic status in 1967-70 and in 1997, and was lower in those who had been current smokers or had a higher blood pressure level in 1967-70. After excluding those with reported cardiovascular disease (25% of respondents), the mean levels of total cholesterol and apolipoprotein B were lower in older age groups, whereas apolipoprotein A1 levels did not vary much with age. Among those with risk factors recorded both in 1967-70 and 1997, the prevalence of smoking had declined by two-thirds (32% in 1970 and 12% in 1997), the prevalence of diabetes had increased (0.3% versus 4.5%), and the mean systolic blood pressure had increased by 16 mmHg (130 versus 146 mmHg), but the diastolic blood pressure had not changed materially (80 versus 81 mmHg), and the measured levels of total cholesterol had increased by 0.5 mmol/l (although that change may be artefactual).

CONCLUSION

Follow-up of vital status in this cohort should permit an assessment of the relevance of risk factors recorded in middle and old age to cardiovascular disease in old age.

Socioeconomic and demographic predictors of mortality and institutional residence among middle aged and older people: results from the Longitudinal Study

STUDY OBJECTIVES

To identify socioeconomic and demographic predictors of long term mortality and institutional residence in old age, taking into account changes in socioeconomic and demographic circumstances between the 1971 and 1981 censuses.

DESIGN

Multivariate logistic regression modelling of outcomes for 10 year age cohorts of each gender. The outcomes were death by 31 December 1992; being in an institution in 1991.

SETTING

Members of the Longitudinal Study (a 1% sample of the British Census): 43,092 men and 50,839 women aged 55-74 in 1971.

MAIN RESULTS

Being in rented accommodation and in a household without access to a car carried 35-45% higher mortality rate over 21 years and similar excess risk of being in an institution in 1991. Marital status and living arrangements were weaker predictors of death but being single was a major predictor of moving to an institution for men. Losing household access to a car was a strong factor for mortality for men and for institutionalisation for men aged 55-64 in 1971. The effects were weaker for women. Moving into rented accommodation was a predictor of both outcomes for women and of death for the younger cohort of men. People who started to live alone in the inter-census period were at reduced risk of dying.

CONCLUSIONS

These results demonstrate persistence of inequalities in health related outcomes throughout old age, both in those with unfavourable circumstances in mid-life and in those who, in later life, have lost earlier advantages.

Design, objectives, and lessons from a pilot 25 year follow up re-survey of survivors in the Whitehall study of London Civil Servants

DESIGN

To assess the feasibility of conducting a re-survey of men who are resident in the United Kingdom 25 years after enrollment in the Whitehall study of London Civil Servants.

METHODS

A random sample of 401 study survivors resident in three health authority areas was selected for this pilot study. They were mailed a request to complete a self administered questionnaire, and then asked to attend their general practice to have their blood pressure, weight, and height measured and a blood sample collected into a supplied vacutainer, and mailed to a central laboratory. Using a 2 x 2 factorial design, the impact of including additional questions on income and of an informant questionnaire on cognitive function was assessed.

RESULTS

Accurate addresses were obtained from the health authorities for 96% of the sample. Questionnaires were received from 73% and blood samples from 61% of the sample. Questions on income had no adverse effect on the response rate, but inclusion of the informant questionnaire did. Between 1970 and 1995 there were substantial changes within men in the mean blood pressure and blood total cholesterol recorded, as reflected by correlation coefficients between 1970 and 1995 values of 0.26, and 0.30 for systolic and diastolic blood pressure and 0.38 for total cholesterol.

CONCLUSION

This pilot study demonstrated the feasibility of conducting a re-survey using postal questionnaires and mailed whole blood samples. The magnitude of change in blood pressure and blood total cholesterol concentrations within individuals was greater than anticipated, suggesting that such remeasurements may be required at different intervals in prospective studies to help interpret risks associations properly. These issues will be considered in a re-survey of the remaining survivors of the Whitehall study.