Diagnosing idiopathic learning disability: a cost-effectiveness analysis of microarray technology in the National Health Service of the United Kingdom

Array based comparative genomic hybridisation (aCGH) is a powerful technique for detecting clinically relevant genome imbalance and can offer 40 to > 1000 times the resolution of karyotyping. Indeed, idiopathic learning disability (ILD) studies suggest that a genome-wide aCGH approach makes 10–15% more diagnoses involving genome imbalance than karyotyping. Despite this, aCGH has yet to be implemented as a routine NHS service. One significant obstacle is the perception that the technology is prohibitively expensive for most standard NHS clinical cytogenetics laboratories. To address this, we investigated the cost-effectiveness of aCGH versus standard cytogenetic analysis for diagnosing idiopathic learning disability (ILD) in the NHS. Cost data from four participating genetics centres were collected and analysed. In a single test comparison, the average cost of aCGH was ￡442 and the average cost of karyotyping was ￡117 with array costs contributing most to the cost difference. This difference was not a key barrier when the context of follow up diagnostic tests was considered. Indeed, in a hypothetical cohort of 100 ILD children, aCGH was found to cost less per diagnosis (￡3,118) than a karyotyping and multi-telomere FISH approach (￡4,957). We conclude that testing for genomic imbalances in ILD using microarray technology is likely to be cost-effective because long-term savings can be made regardless of a positive (diagnosis) or negative result. Earlier diagnoses save costs of additional diagnostic tests. Negative results are cost-effective in minimising follow-up test choice. The use of aCGH in routine clinical practice warrants serious consideration by healthcare providers. Copyright statement The Corresponding Author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive licence (or non exclusive for government employees) on a worldwide basis to the BMJ Publishing Group Ltd, and its Licensees to permit this article (if accepted) to be published in BMJ editions and any other BMJPGL products and to exploit all subsidiary rights, as set out in our licence (bmj.com/advice/copyright.shtml). Authorship The authors included on this paper fulfil the criteria of authorship and no one who fulfils the criteria has been excluded from authorship. The authors made a substantial contribution to the conception, design, analysis and interpretation of data. They were involved in drafting the article or revising it critically for important intellectual content and approving the version to be published. Contributorship Sarah Wordsworth (Guarantor): Planning, conducting and reporting work, interpretation of data, drafting and revising article. James Buchanan: Conducting and reporting work, interpretation of data, revising article. Regina Regan: Completing costing questionnaire, providing protocol details, other costing information, interpretation of data, information about learning disability and genome imbalance and revising article. Val Davison: Completing costing questionnaire, providing protocol details, sharing overall laboratory experience and drafting article. Kim Smith: Completing costing questionnaire, providing protocol details, drafting article. Sara Dyer: Completing costing questionnaire and providing protocol details. Carolyn Campbell: Completing costing questionnaire and providing protocol details. Edward Blair: Critical appraisal of article for clinical content and revising article. Eddy Maher: Completing costing questionnaire, providing protocol details, sharing overall laboratory experience and drafting article. Jenny Taylor: Planning and facilitating work between centres. Drafting and revising article. Samantha JL Knight: Completing costing questionnaire, providing protocol details, other costing information, interpretation of data, providing information about learning disability and genome imbalance, drafting and revising article. Jenny Taylor and Samantha JL Knight contributed equally to the work presented.     

Sex specific response of cultured human bone cells to ERα and ERβ specific agonists by modulation of cell proliferation and creatine kinase specific activity

We have previously reported that human cultured bone cells (hObs) respond to estradiol-17β (E2) by stimulating DNA synthesis, creatine kinase BB specific activity (CK) and other parameters sex-specifically. We now investigate the sex specificity of the response of these hObs to estrogen receptor (ER) α and ERβ specific agonists. Real time PCR revealed that all cells express mRNA for both ERs. ERα mRNA but not ERβ mRNA was stimulated by all estrogenic compounds in both pre- and post-menopausal hObs with no effect in male hObs. Cells treated with E2, 2,3-bis (4-hydroxyphenyl)-propionitrile (DPN; ERβ specific agonist) and 4,4',4″-[4-propyl-(1H)-pyrazol-1,3,5-triyl] tris-phenol (PPT; ERα specific agonist) showed increased DNA synthesis and CK in all female but not male hObs. Raloxifene (Ral), a specific ERα antagonist, inhibited the stimulation of DNA synthesis and CK by E2 or PPT, but not by DPN. DPN and PPT like E2 modulated the expression of both 12 and 15 lipooxygenase (LO) mRNA in both female but not male hObs. 12 and 15 HETE production was modulated only by DPN and PPT in these cells. The LO inhibitor baicaleine inhibited only E2 and PPT but not DPN effects in both female hObs. In conclusion, we provide herein evidence for the separation of age- and sex-dependent mediation via both ERα and ERβ pathways in the effects of estrogens on hObs, with a yet unknown mechanism.     

Strain-dependent proliferation in response to human gastric mucin and adhesion properties of Helicobacter pylori are not affected by co-isolated Lactobacillus sp

Background: Helicobacter pylori colonize the mucus layer that covers the gastric epithelium and can cause gastritis, ulcers, and gastric cancer. Recently, Lactobacillus sp. have also been found to reside in this niche permanently. This study compares adhesive properties and proliferation of co‐isolated lactobacilli and H. pylori in the presence of mucins and investigates possibilities for lactobacilli‐mediated inhibition of H. pylori. Materials and methods: Binding and proliferation of four H. pylori and four Lactobacillus strains, simultaneously isolated after residing in the stomachs of four patients for >4 years, to human gastric mucins were investigated using microtiter‐based methods. Results: The H. pylori strains co‐isolated with lactobacilli exhibited the same mucin binding properties as demonstrated for H. pylori strains previously. In contrast, no binding to mucins was detected with the Lactobacillus strains. Proliferation of mucin‐binding H. pylori strains was stimulated by the presence of mucins, whereas proliferation of non‐binding H. pylori and Lactobacillus strains was unaffected. Associative cultures of co‐isolated H. pylori and Lactobacillus strains showed no inhibition of H. pylori proliferation because of the presence of whole bacteria or supernatant of lactobacilli. Conclusions: The presence of lactobacilli in the stomach did not select for different mucin binding properties of H. pylori, and Lactobacillus sp. did neither compete for binding sites nor inhibit the growth of co‐isolated H. pylori. The effects of human gastric mucins on H. pylori proliferation vary between strains, and the host–bacteria interaction in the mucus niche thus depends on both the H. pylori strain and the microenvironment provided by the host mucins.     

Identification of phenolic compounds in isolated vacuoles of the medicinal plant Catharanthus roseus and their interaction with vacuolar class III peroxidase: an H₂O₂ affair?

Class III peroxidases (Prxs) are plant enzymes capable of using H(2)O(2) to oxidize a range of plant secondary metabolites, notably phenolic compounds. These enzymes are localized in the cell wall or in the vacuole, which is a target for secondary metabolite accumulation, but very little is known about the function of vacuolar Prxs. Here, the physiological role of the main leaf vacuolar Prx of the medicinal plant Catharanthus roseus, CrPrx1, was further investigated namely by studying its capacity to oxidize co-localized phenolic substrates at the expense of H(2)O(2). LC-PAD-MS analysis of the phenols from isolated leaf vacuoles detected the presence of three caffeoylquinic acids and four flavonoids in this organelle. These phenols or similar compounds were shown to be good CrPrx1 substrates, and the CrPrx1-mediated oxidation of 5-O-caffeoylquinic acid was shown to form a co-operative regenerating cycle with ascorbic acid. Interestingly, more than 90% of total leaf Prx activity was localized in the vacuoles, associated to discrete spots of the tonoplast. Prx activity inside the vacuoles was estimated to be 1809 nkat ml(-1), which, together with the determined concentrations for the putative vacuolar phenolic substrates, indicate a very high H(2)O(2) scavenging capacity, up to 9 mM s(-1). Accordingly, high light conditions, known to increase H(2)O(2) production, induced both phenols and Prx levels. Therefore, it is proposed that the vacuolar couple Prx/secondary metabolites represent an important sink/buffer of H(2)O(2) in green plant cells.     

Structural characterization of the O-chain polysaccharide from an environmentally beneficial bacterium Pseudomonas chlororaphis subsp. aureofaciens strain M71

Pseudomonas chlororaphis subsp. aureofaciens strain M71 was isolated from the root of a tomato plant and it was able to control in vivo Fusarium oxysporum f. sp. radicis-lycopersici responsible for the tomato crown and root rot. Recently, strain M71 was evaluated even for its efficacy in controlling Seiridium cardinale, the causal agent of bark canker of common cypress (Cupressus sempervirens L.). Strain M71 ability to persist on the tomato rhizosphere and on the aerial part of cypress plants could be related to the nature of the lipopolysaccharides (LPS) present on the outer membrane and in particular to the O-specific polysaccharide.A neutral O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide from P. chlororaphis subsp. aureofaciens strain M71. By means of compositional analyses and NMR spectroscopy, the chemical repeating unit of the polymer was identified as the following linear trisaccharide.     

Interspecific hybridization in oysters: Restriction Enzyme Digestion Chromosome Banding confirms Crassostrea angulata × Crassostrea gigas F1 hybrids

The taxonomic status of the two commercially important cupped oysters, Crassostrea angulata, the Portuguese oyster (Lamarck, 1819) and Crassostrea gigas, the Japanese oyster (Thunberg, 1793) has long been in question. The recent observation of the hybridization between C. gigas and C. angulata and the production of fertile F1s led us to search for cytogenetic evidence of both parental genomes in the interspecific hybrids. The cytogenetic characterization of the hybrids was performed by the use of restriction endonuclease treatments. This technique has recently shown the potential for individual chromosome identification by banding in oysters. Chromosomes of C. gigas, C. angulata and their hybrids were treated with two different restriction enzymes (ApaI and HaeIII), stained with Giemsa, and examined for banding patterns. These chromosome markers allowed the parental haploid sets to be identified in the hybrids. The analysis of the banded karyotypes of the interspecific hybrids showed that for each chromosome pair, one of the homologues presented a banding pattern consistent with that of C. gigas and the other homologue presented a banding pattern consistent with that of C. angulata. These cytogenetic results substantiate the reported interspecific hybridization between C. gigas and C. angulata. In view of these results and taking into account the present expansion of C. gigas aquaculture in southern Europe, the question of the need for preservation of pure C. angulata stocks should be raised as only a few populations remain in the south of Spain and Portugal. Recently, changes in the genetic composition of populations in southern Portugal have indeed been observed, showing that human activities have created contact zones between the two taxa while no natural sympatric zones exist in Europe.     

Muc5b and Muc5ac are the major oligomeric mucins in equine airway mucus

Horses frequently suffer from respiratory diseases, which, irrespective of etiology, are often associated with airway mucus accumulation. Studies on human airways have shown that the key structural components of the mucus layer are oligomeric mucins, which can undergo changes of expression and properties in disease. However, there is little information on these gel-forming glycoproteins in horse airways mucus. Therefore, the aims of this study were to isolate equine airways oligomeric mucins, characterize their macromolecular properties, and identify their gene products. To this end, pooled tracheal washes, collected from healthy horses and horses suffering from respiratory diseases, were solubilized with 6 M guanidinium chloride (GdmCl). The oligomeric mucins were purified by density gradient centrifugation followed by size exclusion chromatography. Biochemical and biophysical analyses showed the mucins were stiffened random coils in solution that were polydisperse in size (M(r) = 6-20 MDa, average M(r) = 14 MDa) and comprised of disulfide-linked subunits (average M(r) = 7 MDa). Agarose gel electrophoresis showed that the pooled mucus sample contained at least two populations of oligomeric mucins. Electrospray ionization tandem mass spectrometry of tryptic digests of the unfractionated mucin preparation showed that the oligomeric mucins Muc5b and Muc5ac were present. In summary, we have shown that equine airways mucus is a mixture of Muc5b and Muc5ac mucins that have a similar macromolecular organization to their human counterparts. This study will form the basis for future studies to analyze the contribution of these two mucins to equine airways pathology associated with mucus accumulation.     

Nox2 B-loop peptide, Nox2ds, specifically inhibits the NADPH oxidase Nox2

In recent years, reactive oxygen species (ROS) derived from the vascular isoforms of NADPH oxidase, Nox1, Nox2, and Nox4, have been implicated in many cardiovascular pathologies. As a result, the selective inhibition of these isoforms is an area of intense current investigation. In this study, we postulated that Nox2ds, a peptidic inhibitor that mimics a sequence in the cytosolic B-loop of Nox2, would inhibit ROS production by the Nox2-, but not the Nox1- and Nox4-oxidase systems. To test our hypothesis, the inhibitory activity of Nox2ds was assessed in cell-free assays using reconstituted systems expressing the Nox2-, canonical or hybrid Nox1-, or Nox4-oxidase. Our findings demonstrate that Nox2ds, but not its scrambled control, potently inhibited superoxide (O₂^•−) production in the Nox2 cell-free system, as assessed by the cytochrome c assay. Electron paramagnetic resonance confirmed that Nox2ds inhibits O₂^•− production by Nox2 oxidase. In contrast, Nox2ds did not inhibit ROS production by either Nox1- or Nox4-oxidase. These findings demonstrate that Nox2ds is a selective inhibitor of Nox2-oxidase and support its utility to elucidate the role of Nox2 in organ pathophysiology and its potential as a therapeutic agent.