Reversible Control by Vitamin D of Granulocytes and Bacteria in the Lungs of Mice: An Ovalbumin-Induced Model of Allergic Airway Disease

Vitamin D may be essential for restricting the development and severity of allergic diseases and asthma, but a direct causal link between vitamin D deficiency and asthma has yet to be established. We have developed a ‘low dose’ model of allergic airway disease induced by intraperitoneal injection with ovalbumin (1 µg) and aluminium hydroxide (0.2 mg) in which characteristics of atopic asthma are recapitulated, including airway hyperresponsiveness, antigen-specific immunoglobulin type-E and lung inflammation. We assessed the effects of vitamin D deficiency throughout life (from conception until adulthood) on the severity of ovalbumin-induced allergic airway disease in vitamin D-replete and -deficient BALB/c mice using this model. Vitamin D had protective effects such that deficiency significantly enhanced eosinophil and neutrophil numbers in the bronchoalveolar lavage fluid of male but not female mice. Vitamin D also suppressed the proliferation and T helper cell type-2 cytokine-secreting capacity of airway-draining lymph node cells from both male and female mice. Supplementation of initially vitamin D-deficient mice with vitamin D for four weeks returned serum 25-hydroxyvitamin D to levels observed in initially vitamin D-replete mice, and also suppressed eosinophil and neutrophil numbers in the bronchoalveolar lavage fluid of male mice. Using generic 16 S rRNA primers, increased bacterial levels were detected in the lungs of initially vitamin D-deficient male mice, which were also reduced by vitamin D supplementation. These results indicate that vitamin D controls granulocyte levels in the bronchoalveolar lavage fluid in an allergen-sensitive manner, and may contribute towards the severity of asthma in a gender-specific fashion through regulation of respiratory bacteria.     

ALBUMIN CAN REVERSE THE RELEASE OF POTASSIUM FROM HUMAN ERYTHROCYTES TREATED WITH THE NON-IONIC DETERGENT,BRIJ 58

Exchange of erythrocyte intracellular (i/c) K⁺for extracellular (e/c) Na⁺in human erythrocytes treated with sub-CMC concentrations of the non-ionic detergent Brij 58 can be stopped by reincubation in serum or albumin containing solutions. The progressive equilibration of the K⁺contents of detergent-treated human erythrocytes with the incubation medium was reversed by an albumin-mediated withdrawal of detergent molecules from the cell. Re-establishment of near normal [K⁺] in terms of K⁺/kg water proceeds in two ways: (i) a metabolism-dependent net accumulation of K⁺ions; and (ii) a metabolism-independent shrinkage of erythrocytes, this being the more significant factor.     

The clinical significance,natural history and predictors of bone marrow lesion change over eight years

Introduction

There is increasing evidence to suggest that bone marrow lesions (BMLs) play a key role in the pathogenesis of osteoarthritis (OA). However, there is a lack of long term data. The aim of this study was to describe the natural history of knee BMLs, their association with knee pain and examine predictors of BML change over eight years.

Methods

A total of 198 subjects (109 adult offspring of subjects who had a knee replacement and 89 community-based controls) were studied. Knee pain and BML size were assessed at two and ten year visits.

Results

At the two year visit, 64% of participants (n = 127) had 229 BMLs (34% patella, 26% femoral and 40% tibial). Over eight years, 24% (55/229) increased in size, 55% (125/229) remained stable and 21% (49/229) decreased in size or resolved completely. Of the participants without BMLs at baseline, 52% (37/71) developed incident BMLs.After adjusting for confounders, eight year change in total BML size was associated with change in knee pain in offspring (β = 2.50, 95% confidence interval (CI) 0.96 to 4.05) but not controls. This association was stronger in males. Incident BMLs were associated with increase in pain (β = 3.60, 95% CI 1.14 to 6.05). Body mass index (BMI) and strenuous activity (but not radiographic osteoarthritis or smoking) were associated with an increase in BML size.

Conclusion

In this midlife cohort, the proportion of BMLs increasing in size was similar to those decreasing in size with the majority remaining stable. Change in BMLs was predicted by BMI and strenuous activity. An increase in BML size or a new BML resulted in an increase in pain especially in males and those with a family history of OA.     

Pilot study: assessing the clinical diagnosis of allergy in atopic children using a microarray assay in addition to skin prick testing and serum specific IgE

Background

Children with atopic dermatitis (AD) are at risk of developing allergy. Alongside clinical history, testing modalities include skin prick tests (SPT), specific immunoglobulin-E (sp-IgE) and recently, microarray assays. The aim of this pilot study was to assess current tests and the ISAC sIgE-112 system in the diagnosis of food and aeroallergen allergy.

Methods

Children aged 0–11 years with moderate to severe AD were included. An initial allergy assessment including clinical history, SPT and sp-IgE was performed to determine food and aeroallergen sensitization. A second independent clinical assessment using the same information given to the first assessor and ISAC test results for food and aeroallergen sensitization was also made for each participant. The results from both were compared.

Results

30 children [mean age 3.91 years (SD 3.3)] were included; 53.3 and 46.7 % had moderate and severe AD, respectively. Sp-IgE tests had a higher percentage of positive results compared to SPT and ISAC tests for common allergens. There was a significant difference between the three tests in detecting aeroallergen sensitization (p = 0.038), especially between sp-IgE and ISAC tests, but no significant difference between the tests for food allergen sensitization. There was good agreement between the two assessors; 70 % of the children had a change in diagnosis, with 60 % having at least one diagnosis added and 40 % having at least one diagnosis removed.

Conclusions

There is a role for the use of ISAC testing in diagnosing sensitization and allergy in children with AD as it leads to a change in diagnosis for many patients. Further work is required to assess its clinical and cost effectiveness.

     

Molecular engineering of the cellulosome complex for affinity and bioenergy applications

The cellulosome complex has evolved to degrade plant cell walls and, as such, combines tenacious binding to cellulose with diverse catalytic activities against amorphous and crystalline cellulose. Cellulolytic microorganisms provide an extensive selection of domains; those with affinity for cellulose, cohesins and their dockerin binding partners that define cellulosome stoichiometry and architecture, and a range of catalytic activities against carbohydrates. These robust domains provide the building blocks for molecular design. This review examines how protein modules derived from the cellulosome have been incorporated into chimaeric proteins to provide biosynthetic tools for research and industry. These applications include affinity tags for protein purification, and non-chemical methods for immobilisation and presentation of recombinant protein domains on cellulosic substrates. Cellulosomal architecture provides a paradigm for design of enzymatic complexes that synergistically combine multiple catalytic subunits to achieve higher specific activity than would be obtained using free enzymes. Multimeric enzymatic complexes may have industrial applications of relevance for an emerging carbon economy. Biocatalysis will lead to more efficient utilisation of renewable carbon-fixing energy sources with the added benefits of reducing chemical waste streams and reliance on petroleum.     

Acid stress damage of DNA is prevented by Dps binding in <Emphasis Type="Italic">Escherichia coli</Emphasis>O157:H7

Background  

Acid tolerance in Escherichia coli O157:H7 contributes to persistence in its bovine host and is thought to promote passage through the gastric barrier of humans. Dps (DNA-binding protein in starved cells) mutants of E. coli have reduced acid tolerance when compared to the parent strain although the role of Dps in acid tolerance is unclear. This study investigated the mechanism by which Dps contributes to acid tolerance in E. coli O157:H7.     

18S rRNA data indicate that Aschelminthes are polyphyletic in origin and consist of at least three distinct clades

The Aschelminthes is a collection of at least eight animal phyla, historically grouped together because the absence of a true body cavity was perceived as a pseudocoelom. Analyses of 18S rRNA sequences from six Aschelminth phyla (including four previously unpublished sequences) support polyphyly for the Aschelminthes. At least three distinct groups of Aschelminthes were detected: the Priapulida among the protostomes, the Rotifera-Acanthocephala as a sister group to the protostomes, and the Nematoda as a basal group to the triploblastic Eumetazoa.      

Characterization and comparison of Clostridium cellulovorans endoglucanases-xylanases EngB and EngD hyperexpressed in Escherichia coli.

By the use of a T7 expression system, endoglucanases-xylanases EngB and EngD from Clostridium cellulovorans were hyperexpressed and purified from Escherichia coli. The two enzymes demonstrated both endoglucanase and xylanase activities. The substrate specificities of both endoglucanases were similar except that EngD had four-times-greater p-nitrophenyl beta-1,4-cellobiosidase activity. The two proteins were very homologous (80%) up to the Pro-Thr-Thr region which divided the protein into -NH2- and -COOH-terminals. The -COOH- region of EngB has high homology to the endoglucanases and a xylanase from Clostridium thermocellum and to an endoglucanase from Clostridium cellulolyticum and did not show strong binding to cellulose (Avicel). However, the -COOH- region of EngD, which had homology to the cellulose-binding domains of Cellulomonas fimi exo- and endoglucanases and to Pseudomonas fluorescens endoglucanase, demonstrated binding ability to cellulose even when the domain was fused to the N-terminal domain of EngB. By probing the Avicel-purified cellulase complex (F8) with anti-EngB and anti-EngD antibodies, both EngB and EngD were shown to be present on the cellulase complex of C. cellulovorans. Many proteins homologous to EngB and EngD were also present on the complex.