Metabolic alterations in adipose tissue during the early phase of experimental endotoxemia in humans

Adipose tissue plays an important role in energy homeostasis; however, there is only little knowledge about its metabolic activity during critical illness or sepsis. We assessed adipose tissue metabolic activity and local blood flow during experimental endotoxemia in otherwise healthy humans. In a prospective, placebo controlled and randomized experiment we measured changes in lactate, glycerol, and pyruvate concentrations in microdialysate samples of femoral adipose tissue after an intravenous bolus of lipopolysaccharide (LPS, 4 ng/kg). Intravenous endotoxin caused an early and constant increase in interstitial pyruvate, while formation of lactate in adipose tissue was not affected. In contrast, lactate levels in serum were elevated significantly after 90 min (p<0.05) and likewise, serum glycerol concentrations rose 90 min after LPS treatment (p<0.05) and 60 min earlier than in adipose tissue. Subcutaneous adipose tissue blood perfusion increased 2-fold while there was a strong decline in skin blood flow. Pyruvate accumulation in subcutaneous adipose tissue is an early marker of endotoxemia. While adipose tissue is a major source of serum glycerol and lactate in humans during physiological conditions, it contributes only little to increased serum lactate and glycerol levels during endotoxemia.

FADS gene variants modulate the effect of dietary fatty acid intake on allergic diseases in children

BACKGROUND

The association between dietary fatty acid intake and the development of atopic diseases has been inconsistent. This could be due to inter-individual genetic differences in fatty acid metabolism.

OBJECTIVE

The aim of the current study was to assess the influence of FADS1 FADS2 gene cluster polymorphisms on the association between dietary fatty acid intake and atopic diseases and allergic sensitization in 10-year-old children.

METHODS

The analysis was based on data from two German prospective birth cohort studies. Data on margarine and fatty acid intake were collected using a food frequency questionnaire. Information on atopic diseases was collected using a questionnaire completed by the parents. Specific IgE against common food and inhalant allergens were measured. Six variants of the FADS1 FADS2 gene cluster (rs174545, rs174546, rs174556, rs174561, rs174575 and rs3834458) were tested. Logistic regression modelling, adjusted for gender, age, maternal education level and study centre, was used to analyse the association between fatty acid intake and atopic diseases stratified by genotype.

RESULTS

No significant association was found between the six FADS single nucleotide polymorphisms (SNPs) and allergic diseases or atopic sensitization. The total n-3/total n-6 ratio was positive associated with an increased risk of hayfever in homozygous major allele carriers ranging from an adjusted odds ratios of 1.25 (95%-CI: 1.00-1.57) to 1.31 (95%-CI: 1.01-1.69) across the six tested SNPs although this association was not significant anymore after correcting for multiple testing. Daily margarine intake was significantly associated with asthma [1.17 (1.03-1.34) to 1.22 (1.06-1.40)] in individuals carrying the homozygous major allele. This association was also significant after correcting for multiple testing.

CONCLUSIONS & CLINICAL RELEVANCE

The association between dietary intake of fatty acids and allergic diseases might be modulated by FADS gene variants in children.

Infant eczema, infant sleeping problems, and mental health at 10 years of age: the prospective birth cohort study LISAplus

BACKGROUND

Cross-sectional studies suggest an association between eczema and mental health problems, possibly modified by sleeping problems, but prospective evidence is missing. We aimed to prospectively investigate the relationship between infant eczema (within first 2 years of age), infant sleeping problems (within first 2 years of age), and the risk of mental health problems at 10 years of age.

METHODS

Between 1997 and 1999, a population-based birth cohort was recruited in Munich, Leipzig, Wesel, and Bad Honnef, Germany, and followed until 10 years of age. Physician-diagnosed eczema, parent-reported sleeping problems, and known environmental risk factors for atopy were regularly assessed until 10 years of age. Mental health was measured using the Strengths and Difficulties Questionnaire (parent version) at 10 years of age. We applied logistic regression modeling adjusting for environmental and lifestyle factors, allergic comorbidity, and family history of eczema.

RESULTS

From the original cohort of 3097 neonates, 1658 (54%) were followed until age 10, while 1578 (51%) were eligible for analysis. In the fully adjusted model, children with infant eczema were at increased risk of hyperactivity/inattention at 10 years of age [odds ratio (OR) 1.78; 95% confidence interval (95% CI) 1.02-3.09]. Infant eczema with concurrent sleeping problems predicted emotional problems [OR 2.63; 95% confidence interval (95% CI) 1.20-5.76] and conduct problems (OR 3.03; 95% CI 1.01-9.12) at 10 years of age.

CONCLUSIONS

Infant eczema with concurrent sleeping problems appears to be a risk factor for the development of mental health problems.

Association between attendance of day care centres and increased prevalence of eczema in the German birth cohort study LISAplus

BACKGROUND

Day care centre attendance is much more common in East than in West Germany. Although there is evidence that early day care might be protective against atopic diseases, several studies have shown a higher prevalence of childhood eczema in East Germany compared to West Germany.

OBJECTIVES

To compare prevalence and cumulative incidence of eczema in a birth cohort study in East and West Germany and to identify risk factors that are associated with eczema, which might explain regional differences.

METHODS

We used data from the ongoing population-based birth cohort study Influence of Life-style factors on the development of the Immune System and Allergies in East and West Germany Plus the influence of traffic emissions and genetics. In 1997, 3097 children from study areas in East and West Germany were recruited. Cumulative incidence and 1-year prevalences of eczema up to the age of 6 years were determined from yearly questionnaires. Cox regression and generalized estimating equations/logistic regression were used to quantify regional differences and to identify risk factors that might explain them.

RESULTS

Prevalence and incidence of eczema were higher in children living in East Germany than those living in West Germany. We identified 11 risk factors that showed significant regional differences. From these factors, only 'day care attendance during the first 2 years of life' was significantly associated with eczema (odds ratio 1.56, 95% confidence interval CI 1.31-1.86). The regional differences in eczema could be explained by differences in early day care utilization.

CONCLUSION

Day care centre attendance is associated with an increased prevalence and incidence of eczema. Regional differences in eczema prevalence could be explained by regional differences in utilization of early day care.

Respiratory health in children, and indoor exposure to (1,3)-β-D-glucan, EPS mould components and endotoxin

For a long time, exposure to mould and dampness-derived microbial components was considered a risk factor for the development of respiratory diseases and symptoms. Some recent studies suggested that early childhood exposure to mould components, such as (1,3)-β-D-glucan and extracellular polysaccharides (EPSs), may protect children from developing allergy. We investigated the association of exposure to (1,3)-β-D-glucan, EPS and endotoxin with asthma and allergies in 6-yr-old children. This investigation was the follow-up to a nested case-control study among three European birth cohorts. Children from two ongoing birth cohort studies performed in Germany (n = 358) and one in the Netherlands (n = 338) were selected. Levels of (1,3)-β-D-glucan, EPS and endotoxin were measured in settled house dust sampled from children's mattresses and living-room floors when the children were, on average, 5 yrs of age. At the age of 6 yrs, health outcome information was available for 678 children. In the two German subsets, domestic EPS and endotoxin exposure from children's mattresses were significantly negatively associated with physician-diagnosed asthma (OR per interquartile range increase 0.60 (95% CI 0.39-0.92) and 0.55 (95% CI 0.31-0.97), respectively). In addition, EPS exposure was inversely related to physician-diagnosed allergic rhinitis (OR 0.50, 95% CI 0.31-0.81). For the Dutch population, no associations were observed between exposure to microbial agents and respiratory health outcomes. We found inverse associations between domestic exposure to EPS and endotoxin from children's mattresses, and doctor-diagnosed asthma and rhinitis in German, but not in Dutch, school children. The reasons for the differences between countries are not clear.

[Diagnostics for fungal infections of the lungs]

Recognition of and therapy for fungal infections of the lungs still presents problems even for the experienced clinician. The distinction between invasive mycoses of the lungs and fungal colonisations that do not require therapy is cinically difficult and can often not be made satisfactorily even with advanced microbiological diagnostics. One must differentiate between a primary, often locally limited, endemic pulmonary mycosis and a pulmonary mycosis against the background of a locally or systemically compromised immune system. Patients at risk include those with advanced HIV infections, patients under long-term antibiotic therapy as well as oncological and multimorbid patients. The pulmonary manifestation of a mycosis may not only be the starting point for a systemic dissemination but can also arise in the course of hematogenous spread of the infection. The latter can appear, for example, as an invasive pulmonary aspergillosis in immunesuppressed patients. Thus, early clinical, radiological and biological confirmation of the diagnosis is essential in order to avoid the possible complications of pulmonary mycosis.

[Diagnosis of infections in pneumology]

Lower respiratory tract infections rank among the leading causes of morbidity and mortality worldwide. In clinical practice, especially in the care of severely ill patients, discrimination between tracheobronchial colonisation with potentially pathogenic microorganisms and infection is a common diagnostic challenge. While prompt antibiotic treatment is needed in critically ill patients with pneumonia, an inadequate use of antibiotics is the major cause for the emergence of drug-resistant microorganisms. The first part of this review provided a detailed overview of the currently available methods for the diagnosis of pulmonary infectious diseases. In the present second part of the manuscript, we focus upon methods and criteria for the differentiation between lower respiratory tract bacterial colonisation and lower respiratory tract infections, highlighting important pathogens.

[Management of a new influenza A/H1N1 virus pandemic within the hospital. Statement of the German Society of Pneumology]

This update summarized the hospital experience from the first wave of the new influenza A/H1/N1 pandemic.

Common variants in FCER1A influence total serum IgE levels from cord blood up to six years of life

BACKGROUND

In a recent genome wide scan, a functional promoter variant (rs2251746) in the gene encoding the alpha chain of the high affinity receptor for immunoglobulin E (IgE) (FCER1A) was identified as major determinant of serum IgE levels.

OBJECTIVE

The aim of this study was to investigate the role of rs2251746 on total IgE levels measured at different stages of life from birth (cord blood) up to the age of 6 and to evaluate its interaction with the environmental influences in two German birth cohorts.

METHOD

Data from two German birth cohorts were analysed (n = 1043 for the LISA cohort and n = 1842 for the GINI cohort). In the studies, total serum IgE was measured from cord blood, and blood samples taken at the age of 2/3 and 6 years. In a subgroup of the LISA study, house dust samples were collected at age of 3 months and the amount of endotoxin was determined. Random effect models were used to analyse the longitudinal health outcomes.

RESULTS

In the two cohorts, the heterozygote and the rare homozygote of rs2251746 was consistently associated with lower total IgE levels from birth up to the age of 6 years with an allele-dose effect (P < 0.02 for blood samples taken at each time point in both cohorts). No interaction between the two FCER1A encoding gene and environmental exposures including endotoxin, worm infestation and day care centre attendance during early childhood were observed.

CONCLUSION

Common variants in FCER1A strongly influence basal IgE production independently from environmental stimuli. These effects can be observed already in cord blood pointing to altered gene expression in foetus.

Stress-related maternal factors during pregnancy in relation to childhood eczema: results from the LISA Study

BACKGROUND

Stress has been suggested to impact the onset and exacerbation of eczema and other atopic disorders. Whether early exposure to stress-related factors might exert long-term effects remains to be clarified.

OBJECTIVE

The objective of this study was to investigate whether stress-related maternal factors during pregnancy are associated with childhood eczema during the first 6 years of life.

METHODS

Data from 3004 children from a prospective German birth cohort study (LISA) were analyzed. Information from maternity certificates and questionnaire information on unwanted pregnancy were used to evaluate stress-related maternal factors during pregnancy. Prevalence data for physician-diagnosed eczema were available up to the age of 6 years.

RESULTS

Maternal factors during pregnancy were positively associated with childhood eczema in terms of cumulative prevalence up to the age of 2 years (adjusted odds ratio, 1.48; 95% confidence interval, 0.95-2.30) after adjusting for potential confounders. Beyond the second year no increased risk was observed.

CONCLUSIONS

The results of this study suggest that stress-related maternal factors during pregnancy are associated with an increased risk of childhood eczema during the first 2 years of life. The impact of postnatal stress such as parental divorce or separation on this association could not be clarified. Future studies should therefore further elucidate how prenatal and postnatal stress interact and whether prenatal stress might have a programming effect. If future studies confirm the findings of this study, reducing maternal stress during pregnancy might be a possible target in the primary prevention of eczema during childhood.