Lifestyle treatments in cystic fibrosis: The NHS should not pay.

Lifestyle treatments can be defined as those which may have in impact on quality of life but do not affect health outcomes. Particular treatment options may be preferred by patients because they are for example, easier to use, take up less time or taste better. The impact on adherence needs to be considered. Treatment options that promote greater adherence to therapy are likely to be more efficacious and so are not, by definition, lifestyle treatments. The NHS is facing unprecedented financial pressure and resources are limited. When lifestyle treatments are more expensive than standard therapy, they should not be funded by the NHS.

How much of the paediatric core curriculum do medical students remember?

Few educational studies have investigated how well information learned by medical students is retained over time. The primary aim of this study was to investigate how much of the paediatric core curriculum undergraduates remembered a year after originally passing their paediatrics examination. In addition, we looked at whether students' repeat performance is related to their approach to learning. Medical students were presented with 8 out of a possible 46 core curriculum short answer questions (Mark 1). A year later these same students were re-tested, without prior warning, on the same 8 questions (Mark 2) and a further 8 questions (Mark 3) from the bank of 46. The participants also completed the Revised two-factor Study Process Questionnaire to characterise their approach to learning. After a year, students scores had diminished by 51.2 % (95 % CI 48.2-54.2 %, p < 0.0001) from a Mark 1 average of 89.1 % (standard deviation, SD = 9.2 %) to a Mark 2 average of 37.9 % (SD 6.1 %). Students who reported a superficial approach to learning achieved higher scores for mark 1 (4.1 % increase (95 % CI 0.9-7.4 %) per one standard deviation unit increase in Surface Approach score (p = 0.01)). Neither deep nor surface approach to learning significantly predicted performance a year later (Marks 2 and 3). Students had forgotten more than half of the paediatric core curricular content that they had previously proven that they knew for their summative assessment. Adopting either a deep or superficial approach to learning did not predict ability to retain this information a year later.

Pediatric pyoderma gangrenosum with splenic and pulmonary involvement.

An 8-year-old boy presented with ulcers on the lip and limbs, scattered pustules, fever, and general malaise. Further investigation revealed splenic and pulmonary lesions. A diagnosis of pyoderma gangrenosum with splenic and pulmonary involvement was made. The authors have not found a previous report of pediatric pyoderma with splenic involvement in the literature.

British Thoracic Society guideline for respiratory management of children with neuromuscular weakness: commentary.

The British Thoracic Society guideline for respiratory management of children with neuromuscular weakness summarises the available evidence in this field and provides recommendations that will aid healthcare professionals in delivering good quality patient care.

Early use of high-dose riboflavin in a case of Brown-Vialetto-Van Laere syndrome.

Brown-Vialetto-Van Laere syndrome (BVVLS) is a genetic condition caused by a mutation in the C20orf54 gene, which also codes for an intestinal riboflavin transporter. We report the case of a female who presented at 22 months with acute-onset stridor and generalized muscle weakness, in whom a genetic diagnosis of BVVLS was made, and whose symptoms improved on therapy with high-dose riboflavin. She had previously been developing normally and was able to walk at 11 months, then developed progressive muscle weakness at 22 months, and within 2 weeks was unable to sit without support. She also demonstrated stridor and paradoxical breathing indicating diaphragmatic weakness, and required continuous non-invasive ventilation (NIV) through a tracheostomy. After treatment with riboflavin she was able to walk unaided, and her Gross Motor Functional Classification level improved from level IV to level I, having fully regained the motor function she showed before symptom onset. There were no longer signs of diaphragmatic paralysis while on NIV, and she was able to tolerate 10-minute periods off NIV before paradoxical breathing again became apparent. We therefore recommend that in all cases suspected to be in the BVVLS or Fazio-Londe spectrum, early treatment with high-dose riboflavin must be considered.

Identification of common genetic variation that modulates alternative splicing.

Alternative splicing of genes is an efficient means of generating variation in protein function. Several disease states have been associated with rare genetic variants that affect splicing patterns. Conversely, splicing efficiency of some genes is known to vary between individuals without apparent ill effects. What is not clear is whether commonly observed phenotypic variation in splicing patterns, and hence potential variation in protein function, is to a significant extent determined by naturally occurring DNA sequence variation and in particular by single nucleotide polymorphisms (SNPs). In this study, we surveyed the splicing patterns of 250 exons in 22 individuals who had been previously genotyped by the International HapMap Project. We identified 70 simple cassette exon alternative splicing events in our experimental system; for six of these, we detected consistent differences in splicing pattern between individuals, with a highly significant association between splice phenotype and neighbouring SNPs. Remarkably, for five out of six of these events, the strongest correlation was found with the SNP closest to the intron-exon boundary, although the distance between these SNPs and the intron-exon boundary ranged from 2 bp to greater than 1,000 bp. Two of these SNPs were further investigated using a minigene splicing system, and in each case the SNPs were found to exert cis-acting effects on exon splicing efficiency in vitro. The functional consequences of these SNPs could not be predicted using bioinformatic algorithms. Our findings suggest that phenotypic variation in splicing patterns is determined by the presence of SNPs within flanking introns or exons. Effects on splicing may represent an important mechanism by which SNPs influence gene function.

Innate immunity in ocular Chlamydia trachomatis infection: contribution of IL8 and CSF2 gene variants to risk of trachomatous scarring in Gambians.

BACKGROUND: Trachoma, a chronic keratoconjunctivitis caused by Chlamydia trachomatis, is the world's commonest infectious cause of blindness. Blindness is due to progressive scarring of the conjunctiva (trachomatous scarring) leading to in-turning of eyelashes (trichiasis) and corneal opacification. We evaluated the contribution of genetic variation across the chemokine and cytokine clusters in chromosomes 4q and 5q31 respectively to risk of scarring trachoma and trichiasis in a large case-control association study in a Gambian population. METHODS: Linkage disequilibrium (LD) mapping was used to investigate risk effects across the 4q and 5q31 cytokine clusters in relation to the risk of scarring sequelae of ocular Ct infection. Disease association and epistatic effects were assessed in a population based study of 651 case-control pairs by conditional logistic regression (CLR) analyses. RESULTS: LD mapping suggested that genetic effects on risk within these regions mapped to the pro-inflammatory innate immune genes interleukin 8 (IL8) and granulocyte-macrophage colony stimulatory factor (CSF2) loci. The IL8-251 rare allele (IL8-251 TT) was associated with protection from scarring trachoma (OR = 0.29 p = 0.027). The intronic CSF2_27348 A allele in chromosome 5q31 was associated with dose dependent protection from trichiasis, with each copy of the allele reducing risk by 37% (p = 0.005). There was evidence of epistasis, with effects at IL8 and CSF2 loci interacting with those previously reported at the MMP9 locus, a gene acting downstream to IL8 and CSF2 in the inflammatory cascade. CONCLUSION: innate immune response SNP-haplotypes are linked to ocular Ct sequelae. This work illustrates the first example of epistatic effects of two genes on trachoma.

TLR9 polymorphisms in African populations: no association with severe malaria, but evidence of cis-variants acting on gene expression.

BACKGROUND: During malaria infection the Toll-like receptor 9 (TLR9) is activated through induction with plasmodium DNA or another malaria motif not yet identified. Although TLR9 activation by malaria parasites is well reported, the implication to the susceptibility to severe malaria is not clear. The aim of this study was to assess the contribution of genetic variation at TLR9 to severe malaria. METHODS: This study explores the contribution of TLR9 genetic variants to severe malaria using two approaches. First, an association study of four common single nucleotide polymorphisms was performed on both family- and population-based studies from Malawian and Gambian populations (n>6000 individual). Subsequently, it was assessed whether TLR9 expression is affected by cis-acting variants and if these variants could be mapped. For this work, an allele specific expression (ASE) assay on a panel of HapMap cell lines was carried out. RESULTS: No convincing association was found with polymorphisms in TLR9 for malaria severity, in either Gambian or Malawian populations, using both case-control and family based study designs. Using an allele specific expression assay it was observed that TLR9 expression is affected by cis-acting variants, these results were replicated in a second experiment using biological replicates. CONCLUSION: By using the largest cohorts analysed to date, as well as a standardized phenotype definition and study design, no association of TLR9 genetic variants with severe malaria was found. This analysis considered all common variants in the region, but it is remains possible that there are rare variants with association signals. This report also shows that TLR9 expression is potentially modulated through cis-regulatory variants, which may lead to differential inflammatory responses to infection between individuals.

Familial susceptibility to severe respiratory infection in early life.

Lower respiratory tract infections (LRTI) are common in the first year of life and are mostly caused by viruses. Severity of LRTI in infants is associated with early-life environmental factors. Genetic association studies also suggest a role of heredity in susceptibility to acute bronchiolitis. We designed a case control study to further investigate relative importance of familial influences in risk of LRTI in early childhood compared to environmental factors. From a hospital database, we selected 1,308 children (436 cases; 872 controls) living in Oxfordshire. Cases were children under age 5 years admitted to hospital with LRTI. Parental history and other exposures were recorded in cases and controls by postal questionnaire. Maternal history of asthma increased the risk of severe LRTI in the first year of life, independent of subsequent asthma in a child. History of maternal bronchiolitis also increased the risk of infant LRTI. These results further support the possibility that genetic factors play an important role in susceptibility to severe viral respiratory infections in early life, and suggest that this effect may be independent of subsequent childhood asthma.

The value of non-invasive ventilation.

Non-invasive ventilation (NIV) use has increased markedly over the last 10 years. Children being treated with NIV are now a common sight in most paediatric intensive care units and high dependency units and nearly all tertiary respiratory units will look after a cohort of children who use NIV at home. Although the published evidence base for use of NIV in acute and chronic respiratory failure is relatively weak, it is now very unlikely that there will be any more randomised controlled trials of this intervention. Effectiveness of NIV will need to be evaluated on each child as it used. It is important to define the purpose of using NIV in each child, and then determine whether it is effective.

Should Inhaled Corticosteroids Be Used to Treat Recurrent Wheeze in Preschool Children?

Wheeze in preschool children is common. In a small proportion of children, it can be very troublesome, requiring repeated visits for medical attention. Response to treatment is variable and often disappointing. Children with frequent wheeze, particularly if they have a family history of asthma, are likely to benefit from inhaled corticosteroids, in terms of both improved symptom control and reduced number and severity of exacerbations. Children with infrequent episodic wheeze do not benefit from regular inhaled corticosteroids, and their use should be avoided in children with this pattern of wheeze.

Localization of a long-range cis-regulatory element of IL13 by allelic transcript ratio mapping.

It appears that, for many genes, the two alleles possessed by an individual may produce different amounts of transcript. When such allelic differences in transcription are observed for some individuals but not others, a plausible explanation is genetic variation in the cis-acting elements that regulate the gene in question. Here we describe a novel analytical approach that uses such observations, combined with genotyping data from the HapMap project, to define the genomic location of cis-acting regulatory elements. When applied to the human 5q31 chromosomal region, where complex regulatory mechanisms are known to exist, we demonstrate the sensitivity of this approach by locating a highly significant cis-regulatory element operating on IL13 at long range from a position 250 kb upstream from the gene (P = 2 x 10(-6)). As this method is unaffected by other sources of variation, such as environmental and trans-acting genetic factors, it provides a tractable approach for dissecting the complexities of genetic variation in gene regulation.

Accuracy of haplotype reconstruction from haplotype-tagging single-nucleotide polymorphisms.

Many investigators are now using haplotype-tagging single-nucleotide polymorphism (htSNPs) as a way of screening regions of the genome for association with disease. A common approach is to genotype htSNPs in a study population and to use this information to draw inferences about each individual's haplotypic makeup, including SNPs that were not directly genotyped. To test the validity of this approach, we simulated the exercise of typing htSNPs in a large sample of individuals and compared the true and inferred haplotypes. The accuracy of haplotype inference varied, depending on the method of selecting htSNPs, the linkage-disequilibrium structure of the region, and the amount of missing data. At the stage of selection of htSNPs, haplotype-block-based methods required a larger number of htSNPs than did unstructured methods but gave lower levels of error in haplotype inference, particularly when there was a significant amount of missing data. We present a Web-based utility that allows investigators to compare the likely error rates of different sets of htSNPs and to arrive at an economical set of htSNPs that provides acceptable levels of accuracy in haplotype inference.

Genetic variation at the IL10 gene locus is associated with severity of respiratory syncytial virus bronchiolitis.

The intense airway inflammatory response associated with respiratory syncytial virus (RSV) infection may be an important determinant in the severity of the disease. Interleukin (IL)-10 is a key regulatory cytokine known to be secreted during this infection. We investigated the role that IL-10 plays in RSV disease by studying the effects that variation in the IL10 gene has on the outcome of the disease. Eight single nucleotide polymorphisms (SNPs) spanning the IL10 gene were selected, and haplotypes were constructed. SNPs that efficiently tagged these haplotypes were then typed in 580 infants with severe RSV bronchiolitis and in 580 control subjects. None of the SNPs or haplotypes was associated with RSV bronchiolitis. In a subgroup analysis, 2 SNPs (IL10-1117 and IL10-3585) were associated (odds ratio, 1.7; P=.004) with the need for mechanical ventilation. These data are consistent with the theory that IL10 plays a role in the severity of RSV infection in infants.

Evolution of a polymorphic regulatory element in interferon-gamma through transposition and mutation.

Mammalian transposable elements have intrinsic regulatory elements that can activate neighboring genes, and it is speculated that they can also carry extrinsic transactivating DNA sequences to new genomic locations. We have identified a polymorphic segment of the human interferon-gamma promoter region where two adjacent binding sites for NF-kappaB and NFAT originated from the insertion of an Alu element approximately 22-34 MYA. Both binding sites lie outside the Alu consensus sequence but within the boundaries of the insertion, suggesting that this segment of DNA was comobilized when the Alu element moved from another part of the genome. Sequence comparisons and examination of DNA-protein interactions across nine different primate species indicate that the inserted sequence contained the intact NFAT binding site, whereas the ability to bind NF-kappaB evolved through a series of mutations after the insertion. These observations are consistent with the notion that retropseudogenes can comobilize intact regulatory sequences to new locations and thereby influence the evolution of gene regulatory networks; however, the extent to which such events have shaped the evolution of gene regulation remains unknown.

Variants of the chemokine receptor CCR5 are associated with severe bronchiolitis caused by respiratory syncytial virus.

Respiratory syncytial virus (RSV) bronchiolitis is characterized by intense inflammation of the airways, and high levels of proinflammatory cytokines and chemokines can be found in respiratory secretions of affected infants. Important among these chemokines are RANTES (regulated on activation, normal T cell-expressed and -secreted) and macrophage inflammatory-protein alpha, MIP-1alpha, both of which show correlation with severe RSV bronchiolitis. It is not clear whether high levels of these chemokines are important in disease pathogenesis, and this study addresses this question by studying genetic variants of their major receptor, CC chemokine receptor 5. Results from both a case-control and family-based genetic-association analysis show that the -2459G and -2554T variants are associated with severe RSV bronchiolitis (P=.01). It is proposed that these CCR5 variants influence the inflammatory response, and these data provide further evidence of the important role that host genetic variability plays in the determination of disease severity in RSV bronchiolitis.