Rhinitis associated with asthma is distinct from rhinitis alone: The ARIA-MeDALL hypothesis

Asthma, rhinitis and atopic dermatitis (AD) are interrelated clinical phenotypes that partly overlap in the human interactome. The concept of "one-airway-one-disease", coined over 20 years ago, is a simplistic approach of the links between upper- and lower-airway allergic diseases. With new data, it is time to reassess the concept. This article reviews (i) the clinical observations that led to Allergic Rhinitis and its Impact on Asthma (ARIA), (ii) new insights into polysensitisation and multimorbidity, (iii) advances in mHealth for novel phenotype definition, (iv) confirmation in canonical epidemiologic studies, (v) genomic findings, (vi) treatment approaches and (vii) novel concepts on the onset of rhinitis and multimorbidity. One recent concept, bringing together upper- and lower-airway allergic diseases with skin, gut and neuropsychiatric multimorbidities, is the "Epithelial Barrier Hypothesis". This review determined that the "one-airway-one-disease" concept does not always hold true and that several phenotypes of disease can be defined. These phenotypes include an extreme "allergic" (asthma) phenotype combining asthma, rhinitis and conjunctivitis. Rhinitis alone and rhinitis and asthma multimorbidity represent two distinct diseases with the following differences: (i) genomic and transcriptomic background (Toll-Like Receptors and IL-17 for rhinitis alone as a local disease; IL-33 and IL-5 for allergic and non-allergic multimorbidity as a systemic disease), (ii) allergen sensitisation patterns (mono- or pauci-sensitisation versus polysensitisation), (iii) severity of symptoms and (iv) treatment response. In conclusion, rhinitis alone (local disease) and rhinitis with asthma multimorbidity (systemic disease) should be considered as two distinct diseases, possibly modulated by the microbiome, and may be a model for understanding the epidemics of chronic and auto-immune diseases.

An update on prevalence and risk of snus and nicotine replacement therapy during pregnancy and breastfeeding

AIM

In parallel with falling smoking rates, use of the oral moist tobacco product snus increases among women in reproductive age. We report an update on prevalence and effects of maternal use of snus and nicotine replacement therapy (NRT) during pregnancy and breastfeeding.

METHODS

A literature search of human studies in Medline, PubMed and EMBASE was conducted from September 2016 to May 2018, with stepwise screening of abstracts and subsequent relevant full-text papers for inclusion in Scandinavian and English languages.

RESULTS

Based on three studies, the prevalence of snus use in pregnancy was up to 3.4% in the first trimester and 2.1% in the third trimester. In 12 studies, we found increased risk of several adverse effects, especially preterm delivery, stillbirth and small for gestational age associated with maternal snus use during pregnancy. Knowledge on effects of NRT during pregnancy was conflicting and inconclusive in 10 studies. We did not identify any studies on prevalence or potential health effects of snus or NRT during breastfeeding.

CONCLUSION

Few studies with updated data on the prevalence and adverse health effects of maternal use of snus and NRT during pregnancy were found. No studies during breastfeeding were identified.

Google Trends terms reporting rhinitis and related topics differ in European countries

Google Trends (GT) searches trends of specific queries in Google and reflects the real-life epidemiology of allergic rhinitis. We compared Google Trends terms related to allergy and rhinitis in all European Union countries, Norway and Switzerland from 1 January 2011 to 20 December 2016. The aim was to assess whether the same terms could be used to report the seasonal variations of allergic diseases. Using the Google Trend 5-year graph, an annual and clear seasonality of queries was found in all countries apart from Cyprus, Estonia, Latvia, Lithuania and Malta. Different terms were found to demonstrate seasonality depending on the country - namely 'hay fever', 'allergy' and 'pollen' - showing cultural differences. A single set of terms cannot be used across all European countries, but allergy seasonality can be compared across Europe providing the above three terms are used. Using longitudinal data in different countries and multiple terms, we identified an awareness-related spike of searches (December 2016).

Building Bridges for Innovation in Ageing: Synergies between Action Groups of the EIP on AHA

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma and rhinitis and (3) to develop guidelines with all stakeholders that could be used globally for all countries and populations. ARIA—disseminated and implemented in over 70 countries globally—is now focusing on the implementation of emerging technologies for individualized and predictive medicine. MASK [MACVIA (Contre les Maladies Chroniques pour un Vieillissement Actif)-ARIA Sentinel NetworK] uses mobile technology to develop care pathways for the management of rhinitis and asthma by a multi-disciplinary group and by patients themselves. An app (Android and iOS) is available in 20 countries and 15 languages. It uses a visual analogue scale to assess symptom control and work productivity as well as a clinical decision support system. It is associated with an inter-operable tablet for physicians and other health care professionals. The scaling up strategy uses the recommendations of the European Innovation Partnership on Active and Healthy Ageing. The aim of the novel ARIA approach is to provide an active and healthy life to rhinitis sufferers, whatever their age, sex or socio-economic status, in order to reduce health and social inequalities incurred by the disease.

Paving the way of systems biology and precision medicine in allergic diseases: the MeDALL success story: Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015

MeDALL (Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015) has proposed an innovative approach to develop early indicators for the prediction, diagnosis, prevention and targets for therapy. MeDALL has linked epidemiological, clinical and basic research using a stepwise, large-scale and integrative approach: MeDALL data of precisely phenotyped children followed in 14 birth cohorts spread across Europe were combined with systems biology (omics, IgE measurement using microarrays) and environmental data. Multimorbidity in the same child is more common than expected by chance alone, suggesting that these diseases share causal mechanisms irrespective of IgE sensitization. IgE sensitization should be considered differently in monosensitized and polysensitized individuals. Allergic multimorbidities and IgE polysensitization are often associated with the persistence or severity of allergic diseases. Environmental exposures are relevant for the development of allergy-related diseases. To complement the population-based studies in children, MeDALL included mechanistic experimental animal studies and in vitro studies in humans. The integration of multimorbidities and polysensitization has resulted in a new classification framework of allergic diseases that could help to improve the understanding of genetic and epigenetic mechanisms of allergy as well as to better manage allergic diseases. Ethics and gender were considered. MeDALL has deployed translational activities within the EU agenda.

Developmental determinants in non-communicable chronic diseases and ageing

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.

Can early skin care normalise dry skin and possibly prevent atopic eczema? A pilot study in young infants

BACKGROUND

Atopic eczema (AE) affects approximately 20% of children in Northern countries. Onset during early infancy is common and is characterised by altered skin barrier, increased water loss and defective lipid layer. Restoration of skin barrier by emollients and/or oil baths is an important part of AE treatment, but its role in preventing xerosis and AE is unknown. The present pilot study aimed to assess if xerosis, and possibly AE, could be reduced at six months of age by early introduction of frequent oil baths/facial fat cream in infants with dry skin.

METHODS

A controlled intervention pilot study included 56 six-week-old infants with xerosis, but not AE. Skin quality score ranging from 0 (normal skin) to 4 (probable AE), was assessed at inclusion, three and six months of age, with skin quality at six months as main outcome. One well baby clinic was recruited for intervention, frequent skin care (oil bath (0.5 dl) and facial fat cream, five well baby clinics recruited for observation only.

RESULTS

The intervention group (n=24) had more often normal skin (75%) at six months than the observation group (37.5%) (p<0.001), and less often probable AE (4.0 vs. 19.0%, respectively, ns). Oil baths were performed regularly, 2-4 up to 5-7 times/week in the intervention group, vs. fewer oil baths with sparse volume of oil in the observation group. No adverse reactions were reported.

CONCLUSION

Regular oil baths in infants seem to reduce xerosis and may possibly reduce atopic eczema.

Integrated care pathways for airway diseases (AIRWAYS-ICPs)

The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers).

Allergic Rhinitis and its Impact on Asthma (ARIA): achievements in 10 years and future needs

Allergic rhinitis (AR) and asthma represent global health problems for all age groups. Asthma and rhinitis frequently coexist in the same subjects. Allergic Rhinitis and its Impact on Asthma (ARIA) was initiated during a World Health Organization workshop in 1999 (published in 2001). ARIA has reclassified AR as mild/moderate-severe and intermittent/persistent. This classification closely reflects patients' needs and underlines the close relationship between rhinitis and asthma. Patients, clinicians, and other health care professionals are confronted with various treatment choices for the management of AR. This contributes to considerable variation in clinical practice, and worldwide, patients, clinicians, and other health care professionals are faced with uncertainty about the relative merits and downsides of the various treatment options. In its 2010 Revision, ARIA developed clinical practice guidelines for the management of AR and asthma comorbidities based on the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system. ARIA is disseminated and implemented in more than 50 countries of the world. Ten years after the publication of the ARIA World Health Organization workshop report, it is important to make a summary of its achievements and identify the still unmet clinical, research, and implementation needs to strengthen the 2011 European Union Priority on allergy and asthma in children.

Severe chronic allergic (and related) diseases: a uniform approach--a MeDALL--GA2LEN--ARIA position paper

Concepts of disease severity, activity, control and responsiveness to treatment are linked but different. Severity refers to the loss of function of the organs induced by the disease process or to the occurrence of severe acute exacerbations. Severity may vary over time and needs regular follow-up. Control is the degree to which therapy goals are currently met. These concepts have evolved over time for asthma in guidelines, task forces or consensus meetings. The aim of this paper is to generalize the approach of the uniform definition of severe asthma presented to WHO for chronic allergic and associated diseases (rhinitis, chronic rhinosinusitis, chronic urticaria and atopic dermatitis) in order to have a uniform definition of severity, control and risk, usable in most situations. It is based on the appropriate diagnosis, availability and accessibility of treatments, treatment responsiveness and associated factors such as comorbidities and risk factors. This uniform definition will allow a better definition of the phenotypes of severe allergic (and related) diseases for clinical practice, research (including epidemiology), public health purposes, education and the discovery of novel therapies.

[ARIA (Allergic Rhinitis and its Impact on Asthma) achievements in 10 years and future needs]

Allergic rhinitis and asthma represent global health problems for all age groups. Asthma and rhinitis frequently co-exist in the same subjects. Allergic Rhinitis and its Impact on Asthma (ARIA) was initiated during a World Health Organization (WHO) workshop in 1999 and was published in 2001. ARIA has reclassified allergic rhinitis as mild/moderate-severe and intermittent/persistent. This classification schema closely reflects the impact of allergic rhinitis on patients. In its 2010 Revision, ARIA developed clinical practice guidelines for the management of allergic rhinitis and asthma co-morbidities based on GRADE (Grading of Recommendation, Assessment, Development and Evaluation). ARIA has been disseminated and implemented in over 50 countries of the world. In Turkey, it is important to make a record of ARIA achievements and to identify the still unmet clinical, research and implementation needs in order to strengthen the 2011 EU Priority on allergy and asthma in children.

Practical guide to skin prick tests in allergy to aeroallergens

This pocket guide is the result of a consensus reached between members of the Global Allergy and Asthma European Network (GA(2) LEN) and Allergic Rhinitis and its Impact on Asthma (ARIA). The aim of the current pocket guide is to offer a comprehensive set of recommendations on the use of skin prick tests in allergic rhinitis-conjunctivitis and asthma in daily practice. This pocket guide is meant to give simple answers to the most frequent questions raised by practitioners in Europe, including 'practicing allergists', general practitioners and any other physicians with special interest in the management of allergic diseases. It is not a long or detailed scientific review of the topic. However, the recommendations in this pocket guide were compiled following an in-depth review of existing guidelines and publications, including the 1993 European Academy of Allergy and Clinical Immunology position paper, the 2001 ARIA document and the ARIA update 2008 (prepared in collaboration with GA(2) LEN). The recommendations cover skin test methodology and interpretation, allergen extracts to be used, as well as indications in a variety of settings including paediatrics and developing countries.

Do allergic families avoid keeping furry pets?

Studies addressing the relationship between pet keeping and development of asthma and allergies may be influenced by pet avoidance in families with a history of allergic disease. Following a cohort of 1019 children in Oslo till 10 years of age, we studied the association of pet keeping with socio-economic factors and allergic disease in the family. A family history of asthma and rhinoconjunctivitis was not significantly associated with pet ownership at birth or with pet removal by 10 years. Acquiring cats and dogs was less likely if the child had allergic rhinoconjunctivitis, whereas no association was seen with asthma (in any family member). Single parenthood increased the likelihood of acquiring a cat, smoking parents more often had cats or dogs, and having older siblings was associated with keeping dogs and other furry pets. Among 319 families reporting pet avoidance, 70% never had pets, 8% had given up pets, and 22% avoided a particular type of pet only. Twenty-four per cent of the parents failed to retrospectively report pet keeping during the child's first year of life. Overall, allergic rhinitis, but not asthma was associated with actual pet avoidance, whereas the strongest predictors for keeping pets were found to be socio-economic factors.

PRACTICAL IMPLICATIONS

Allergic disease in a child most often does not lead to the removal of the family's furry pet. Pet avoidance is associated with allergic symptoms, but not asthma. Socio-economic factors like parental education, single parenthood and smoking affects the families' decisions on pet keeping, including the type of pets the families will avoid or acquire. The large recall error demonstrated points to the need for prospective data regarding pet keeping.

Norwegian adolescents with asthma are physical active and fit

BACKGROUND

Evidence regarding habitual physical activity levels and aerobic fitness of asthmatic compared to nonasthmatic children and adolescents is contradictory, and it is unclear if low physical activity levels can contribute to asthma development. The present study therefore aimed to determine whether adolescents with asthma have reduced physical activity levels and aerobic fitness, or increased energy intake and body fat compared to controls.

METHODS

From the environment and childhood asthma study in Oslo, 174 (13- to 14-year old) adolescents, 95 (66 boys) with and 79 (41 boys) without asthma performed maximal running on a treadmill with oxygen consumption measurement (aerobic fitness) and had the sum of four skinfolds and waist circumference recorded (body fat), followed by wearing an activity monitor and registering diet for four consecutive days. Asthma was defined by at least two of the following three criteria fulfilled: (1) dyspnoea, chest tightness and/or wheezing; (2) a doctor's diagnosis of asthma; (3) use of asthma medication. Participants with asthma used their regular medications.

RESULTS

Neither aerobic fitness, total energy expenditure nor hours in moderate to very vigorous intensity physical activity during week and weekend differed between adolescents with and without asthma. Energy intake and body fat was similar in both groups.

CONCLUSIONS

Total energy expenditure, aerobic fitness and hours in moderate to very vigorous intensity physical activity were not reduced and energy intake and body fat measured with skinfolds not increased among Norwegian adolescents with asthma.

A TLR2 polymorphism is associated with type 1 diabetes and allergic asthma

Type 1 diabetes (T1D) and allergic asthma are immune-mediated diseases. Pattern recognition receptors are proteins expressed by cells in the immune system to identify microbial pathogens and endogenous ligands. Toll-like receptors (TLRs) and CD14 are members of this family and could represent a molecular link between microbial infections and immune-mediated diseases. Diverging hypotheses regarding whether there exists a common or inverse genetic etiology behind these immune-mediated diseases have been presented. We aimed to test whether there exist common or inverse associations between polymorphisms in the pattern recognition receptors TLR2, TLR4 and CD14 and T1D and allergic asthma. Eighteen single nucleotide polymorphisms (SNPs) were genotyped in TLR2 (2), TLR4 (12) and CD14 (4) in 700 T1D children, 357 nuclear families with T1D children and 796 children from the 'Environment and Childhood Asthma' study. Allele and haplotype frequencies were analyzed in relation to diseases and in addition transmission disequilibrium test analyses were performed in the family material. Both T1D and allergic asthma were significantly associated with the TLR2 rs3804100 T allele and further associated with the haplotype including this SNP, possibly representing a susceptibility locus common for the two diseases. Neither TLR4 nor CD14 were associated with T1D or allergic asthma.

Severity of obstructive airways disease by age 2 years predicts asthma at 10 years of age

BACKGROUND

Predicting school-age asthma from obstructive airways disease (OAD) in early life is difficult, even when parental and children's atopic manifestations are taken into consideration.

OBJECTIVE

To assess if the severity of OAD in the first 2 years of life predicts asthma at 10 years of age.

METHODS

From a nested case control study within the Environment and Childhood Asthma study, 233 2-year-old subjects with recurrent (> or = 2 episodes) bronchial obstruction (rBO+) and 216 subjects without bronchial obstruction (rBO-) underwent clinical examination, parental interview, treadmill test and metacholine bronchial hyperresponsiveness (BHR) measurement at 10 years. A severity score at 2 years was calculated by frequency, persistence of bronchial obstruction and hospital admissions because of OAD.

MAIN OUTCOMES

Current asthma at 10 years (asthma with symptoms and/or asthma medication during the past year and/or positive treadmill test). Secondary outcome was metacholine BHR at 10 years.

RESULTS

Compared with rBO- subjects, adjusted odds ratio (95% CI) of current asthma among rBO+ was 7.9 (4.1, 15.3), and among rBO+ with a severity score of > 5, 20.2 (9.9, 41.3). In receiver operated characteristic analysis, positive and negative predictive values demonstrated the applicability and value of the score, with an optimal cut-off at severity score 5. Children with severity score > 5 had severe BHR more often (PD20 metacholine < 1 micromol) than children with a lower or 0 score (p = 0.0041).

CONCLUSION

Using a simple scoring system, a high severity score of OAD by 2 years of age is a strong risk factor for, and may predict, current asthma at 10 years of age.

Standard skin prick testing and sensitization to inhalant allergens across Europe--a survey from the GALEN network

Skin prick testing (SPT) is the standard method for diagnosing allergic sensitization but is to some extent performed differently in clinical centres across Europe. There would be advantages in harmonizing the standard panels of allergens used in different European countries, both for clinical purposes and for research, especially with increasing mobility within Europe and current trends in botany and agriculture. As well as improving diagnostic accuracy, this would allow better comparison of research findings in European allergy centres. We have compared the different SPT procedures operating in 29 allergy centres within the Global Allergy and Asthma European Network (GA(2)LEN). Standard SPT is performed similarly in all centres, e.g. using commercial extracts, evaluation after 15-20 min exposure with positive results defined as a wheal >3 mm diameter. The perennial allergens included in the standard SPT panel of inhalant allergens are largely similar (e.g. cat: pricked in all centres; dog: 26 of 29 centres and Dermatophagoides pteronyssinus: 28 of 29 centres) but the choice of pollen allergens vary considerably, reflecting different exposure and sensitization rates for regional inhalant allergens. This overview may serve as reference for the practising doctor and suggests a GA(2)LEN Pan-European core SPT panel.

Acid suppression does not change respiratory symptoms in children with asthma and gastro-oesophageal reflux disease

BACKGROUND

Epidemiological studies have shown an association between gastro-oesophageal reflux disease (GORD) and asthma, and oesophageal acid perfusion may cause bronchial constriction. However, no causative relation has been proven.

AIM

To assess whether acid suppression would lead to reduced asthma symptoms in children with concomitant asthma and GORD.

METHODS

Thirty eight children (mean age 10.8 years, range 7.2-16.8; 29 males) with asthma and a reflux index > or =5.0 assessed by 24 hour oesophageal pH monitoring were randomised to 12 weeks of treatment with omeprazole 20 mg daily or placebo. The groups were similar in age, gender, mean reflux index, and asthma severity. Primary endpoints were asthma symptoms (daytime wheeze, symptoms at night, in the morning, and during exercise) and quality of life (PAQLQ). Secondary endpoints were changes in lung function and the use of short acting bronchodilators. At the end of the study a repeated pH study was performed to confirm the efficacy of acid suppression.

RESULTS

The change in total symptom score did not differ significantly between the omeprazole and the placebo group, and decreased by 1.28 (95% CI -0.1 to 2.65) and 1.28 (95% CI -0.72 to 3.27) respectively. The PAQLQ score increased by 0.62 (95% CI 0.29 to 0.95) in the omeprazole group compared to 0.50 (95% CI 0.29 to 0.70) in the placebo group. Change in lung function and use of short acting bronchodilators were similar in the groups. The acid suppression was adequate (reflux index <5.0) under omeprazole treatment.

CONCLUSION

Omeprazole treatment did not improve asthma symptoms or lung function in children with asthma and GORD.

Perinatal risk factors for recurrent wheeze in early life

The possible value of tidal flow volume (TFV) loops measured at birth in relation to the risk of developing recurrent or persistent bronchial obstruction within two years of life was assessed. TFV loops were measured at a mean age of 2.7 days in 802 neonates enrolled in the 'Environment and Childhood Asthma' (ECA) study in Oslo. Of these, 77 children developed recurrent or persistent bronchial obstruction (cases) and were included in a nested case-control study within the ECA study; 88 controls (the child born closest in time to the case), with no history of bronchial obstruction in the first two years of life, were also included. Information on socio-economic factors, parental atopic diseases and parental smoking habits during the pregnancy was collected from a questionnaire completed by the parents in the maternity ward, and cord blood IgE (CB-IgE) was determined as part of routine sampling in the delivery ward. Mean tPTEF/tE (time to reach peak flow to total expiratory time) was slightly lower in cases (0.31; 95% CI 0.28-0.34) than in controls (0.33; 0.31-0.35) (difference not significant), whereas geometric mean CB-IgE was significantly higher among cases (0.39; 0.30-0.52) than controls (0.27; 0.23-0.33). No significant differences between cases and controls were found for respiratory rate, peak tidal expiratory flow or expiratory volume. However, the odds ratio for developing recurrent or persistent bronchial obstruction was 3.5 (1.1-11.6) if tPTEF/tE was < 0.20 and 4.1 (1.1-14.5) with maternal daily smoking during the pregnancy, after adjusting for age, weight, sex, CB-IgE, parental atopy, maternal education and family income. The TFV parameter tpTEF/tE < 0.20 measured within the first week of life as well as maternal daily smoking during pregnancy are significant, independent risk factors for developing recurrent or persistent bronchial obstruction within the first two years of life.