W E Ollier

The University of Manchester, Manchester, England, United Kingdom

Are you W E Ollier?

Claim your profile

Publications (513)2161.11 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives/HypothesisAge-related hearing loss has a genetic component, but there have been limited genetic studies in this field. Both N-acetyltransferase 2 and apolipoprotein E genes have previously been associated. However, these studies have either used small sample sizes, examined a limited number of polymorphisms, or have produced conflicting results. Here we use a haplotype tagging approach to determine association with age-related hearing loss and investigate epistasis between these two genes.Study DesignCandidate gene association study of a continuous phenotype.Methods We investigated haplotype tagging single nucleotide polymorphisms in the N-acetyltransferase 2 gene and the presence/absence of the apolipoprotein E ε4 allele for association with age-related hearing loss in a cohort of 265 Caucasian elderly volunteers from Greater Manchester, United Kingdom. Hearing phenotypes were generated using principal component analysis of the hearing threshold levels for the better ear (severity, slope, and concavity). Genotype data for the N-acetyltransferase 2 gene was obtained from existing genome-wide association study data from the Illumina 610-Quadv1 chip. Apolipoprotein E genotyping was performed using Sequenom technology. Linear regression analysis was performed using Plink and Stata software.ResultsNo significant associations (P value, > 0.05) were observed between the N-acetyltransferase 2 or apolipoprotein E gene polymorphisms and any hearing factor. No significant association was observed for epistasis analysis of apolipoprotein E ε4 and the N-acetyltransferase 2 single nucleotide polymorphism rs1799930 (NAT2*6A).Conclusion We found no evidence to support that either N-acetyltransferase 2 or apolipoprotein E gene polymorphisms are associated with age-related hearing loss in a cohort of 265 elderly volunteers.Level of EvidenceN/A. Laryngoscope, 2014
    The Laryngoscope 08/2014; · 1.98 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cognitive abilities vary among people. About 40-50% of this variability is due to general intelligence (g), which reflects the positive correlation among individuals' scores on diverse cognitive ability tests. g is positively correlated with many life outcomes, such as education, occupational status, and health, motivating the investigation of its underlying biology. In psychometric research, a distinction is made between general fluid intelligence (gF) - the ability to reason in novel situations - and general crystallized intelligence (gC) - the ability to apply acquired knowledge. This distinction is supported by developmental and cognitive neuroscience studies. Classical epidemiological studies and recent genome-wide association studies (GWASs) have established that these cognitive traits have a large genetic component. However, no robust genetic associations have been published thus far due largely to the known polygenic nature of these traits and insufficient sample sizes. Here, using two GWAS datasets, in which the polygenicity of gF and gC traits was previously confirmed, a gene- and pathway-based approach was undertaken with the aim of characterizing and differentiating their genetic architecture. Pathway analysis, using genes selected on the basis of relaxed criteria, revealed notable differences between these two traits. gF appeared to be characterized by genes affecting the quantity and quality of neurons and therefore neuronal efficiency, whereas long term depression (LTD) seemed to underlie gC. Thus, this study supports the gF-gC distinction at the genetic level and identifies functional annotations and pathways worthy of further investigation.
    Genes Brain and Behavior 06/2014; · 3.60 Impact Factor
  • Annals of the rheumatic diseases 05/2014; · 8.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cranial cruciate ligament rupture (CCLR) is the most common cause of pelvic limb lameness in dogs. To investigate the genetic basis of canine CCLR, we conducted a genome-wide association study using a canine SNP array in Newfoundland pedigree dogs with and without CCLR (n = 96). We identified three main chromosomal regions of CCLR association (on chromosomes 1, 3 and 33). Each of these regions was confirmed by Sequenom genotyping in a further cohort of Newfoundlands (n = 271). The results, particularly SNPs identified in the SORCS2 and SEMA5B genes, suggest that there may be neurological pathways involved in susceptibility to canine CCLR.
    Animal Genetics 05/2014; · 2.58 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess candidate genes for association with osteoarthritis (OA) and identify promising genetic factors and, secondarily, to assess the candidate gene approach in OA. A total of 199 candidate genes for association with OA were identified using Human Genome Epidemiology (HuGE) Navigator. All of their single-nucleotide polymorphisms (SNPs) with an allele frequency of >5% were assessed by fixed-effects meta-analysis of 9 genome-wide association studies (GWAS) that included 5,636 patients with knee OA and 16,972 control subjects and 4,349 patients with hip OA and 17,836 control subjects of European ancestry. An additional 5,921 individuals were genotyped for significantly associated SNPs in the meta-analysis. After correction for the number of independent tests, P values less than 1.58 × 10(-5) were considered significant. SNPs at only 2 of the 199 candidate genes (COL11A1 and VEGF) were associated with OA in the meta-analysis. Two SNPs in COL11A1 showed association with hip OA in the combined analysis: rs4907986 (P = 1.29 × 10(-5) , odds ratio [OR] 1.12, 95% confidence interval [95% CI] 1.06-1.17) and rs1241164 (P = 1.47 × 10(-5) , OR 0.82, 95% CI 0.74-0.89). The sex-stratified analysis also showed association of COL11A1 SNP rs4908291 in women (P = 1.29 × 10(-5) , OR 0.87, 95% CI 0.82-0.92); this SNP showed linkage disequilibrium with rs4907986. A single SNP of VEGF, rs833058, showed association with hip OA in men (P = 1.35 × 10(-5) , OR 0.85, 95% CI 0.79-0.91). After additional samples were genotyped, association at one of the COL11A1 signals was reinforced, whereas association at VEGF was slightly weakened. Two candidate genes, COL11A1 and VEGF, were significantly associated with OA in this focused meta-analysis. The remaining candidate genes were not associated.
    Arthritis & rheumatology (Hoboken, N.J.). 04/2014; 66(4):940-9.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Cranial Cruciate Ligament rupture (CCLR) is one of the most common forms of lameness in dogs and is analogous to rupture of the anterior cruciate ligament in humans, for which it can serve as a model. As there is a strong breed-related predisposition to CCLR in dogs (1), a study was undertaken to consider putative genetic components in susceptible dog breeds. A candidate gene, single nucleotide polymorphism (SNP) genotyping approach using MALDI-TOF mass spectrometry (Sequenom Ltd) was designed to investigate several CCLR-susceptible dog breeds and identify CCLR-associated genes/gene regions that may confer susceptibility or resistance. A meta-analysis was performed using the breed case/control candidate gene data to identify SNP associations that were common to the whole cohort of susceptible dogs. We identified SNPs in key genes involved in ligament strength, stability and extracellular matrix formation (COL5A1, COL5A2, COL1A1, COL3A1, COL11A1, COL24A1, FBN1, LOX, LTBP2) which were significantly associated with CCLR susceptibility across the dog breeds used in this study. These SNPs could have an involvement in CCLR due to a detrimental effect on ligament structure and strength. This is the first published candidate gene study that has revealed significant genetic associations with canine CCLR.
    Connective tissue research 04/2014; · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Canine anal furunculosis (AF) is characterised by ulceration and fistulation of perianal tissue and is a disease that particularly affects German shepherd dogs (GSDs). There are some similarities between AF and perianal Crohn's disease (CD) in man. An immune-mediated aetiopathogenesis for AF has been suggested due to tissue pathology, a major histocompatibility complex (MHC) association and clinical response to ciclosporin. Genome-wide association studies (GWAS) can be conducted in dogs with fewer markers and individuals than would be required in a human study. A discovery GWAS was performed on 21 affected and 25 control GSDs from the UK. No SNPs reached genome-wide significance levels at this stage. However, 127 nominally associated SNPs were genotyped in further 76 cases and 191 controls from the UK and Finland. Sequencing of these regions was undertaken to discover novel genetic variation. Association testing of these variants in the UK and Finnish cohorts revealed nine significantly associated SNPs, six of which cause non-synonymous changes in protein sequence. The ADAMTS16 and CTNND2 gene regions were most significantly associated with disease. Members of the butyrophilin protein family, important in intestinal inflammatory regulation, were also associated with disease, but their independence from the MHC region remains to be established. The CTNND2 gene region is also interesting as this locus was implicated in human ulcerative colitis and CD, albeit at a different candidate gene: DAP. We suggest that this represents a common association between inflammatory bowel disease-related conditions in both species and believe that future studies will strengthen this link.
    Immunogenetics 03/2014; · 2.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Gene variants known to contribute to Autoimmune Addison's disease (AAD) susceptibility include those at the MHC, MICA, CIITA, CTLA4, PTPN22, CYP27B1, NLRP-1 and CD274 loci. The majority of the genetic component to disease susceptibility has yet to be accounted for. To investigate the role of 19 candidate genes in AAD susceptibility in six European case-control cohorts. A sequential association study design was employed with genotyping using Sequenom iPlex technology. In phase one, 85 SNPs in 19 genes were genotyped in UK and Norwegian AAD cohorts (691 AAD, 715 controls). In phase two, 21 SNPs in 11 genes were genotyped in German, Swedish, Italian and Polish cohorts (1264 AAD, 1221 controls). In phase three, to explore association of GATA3 polymorphisms with AAD and to determine if this association extended to other autoimmune conditions, 15 SNPs in GATA3 were studied in UK and Norwegian AAD cohorts, 1195 type 1 diabetes patients from Norway, 650 rheumatoid arthritis patients from New Zealand and in 283 UK Graves' disease patients. Meta-analysis was used to compare genotype frequencies between the participating centres, allowing for heterogeneity. We report significant association with alleles of two STAT4 markers in AAD cohorts (rs4274624: P = 0.00016; rs10931481: P = 0.0007). In addition, nominal association of AAD with alleles at GATA3 was found in 3 patient cohorts and supported by meta-analysis. Association of AAD with CYP27B1 alleles was also confirmed, which replicates previous published data. Finally, nominal association was found at SNPs in both the NF-κB1 and IL23A genes in the UK and Italian cohorts respectively. Variants in the STAT4 gene, previously associated with other autoimmune conditions, confer susceptibility to AAD. Additionally, we report association of GATA3 variants with AAD: this adds to the recent report of association of GATA3 variants with rheumatoid arthritis.
    PLoS ONE 01/2014; 9(3):e88991. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Differences in general cognitive ability (intelligence) account for approximately half of the variation in any large battery of cognitive tests and are predictive of important life events including health. Genome-wide analyses of common single-nucleotide polymorphisms indicate that they jointly tag between a quarter and a half of the variance in intelligence. However, no single polymorphism has been reliably associated with variation in intelligence. It remains possible that these many small effects might be aggregated in networks of functionally linked genes. Here, we tested a network of 1461 genes in the postsynaptic density and associated complexes for an enriched association with intelligence. These were ascertained in 3511 individuals (the Cognitive Ageing Genetics in England and Scotland (CAGES) consortium) phenotyped for general cognitive ability, fluid cognitive ability, crystallised cognitive ability, memory and speed of processing. By analysing the results of a genome wide association study (GWAS) using Gene Set Enrichment Analysis, a significant enrichment was found for fluid cognitive ability for the proteins found in the complexes of N-methyl-D-aspartate receptor complex; P=0.002. Replication was sought in two additional cohorts (N=670 and 2062). A meta-analytic P-value of 0.003 was found when these were combined with the CAGES consortium. The results suggest that genetic variation in the macromolecular machines formed by membrane-associated guanylate kinase (MAGUK) scaffold proteins and their interaction partners contributes to variation in intelligence.
    Translational psychiatry. 01/2014; 4:e341.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous functional gene group analyses implicated common single nucleotide polymorphisms (SNPs) in heterotrimeric G protein coding genes as being associated with differences in human intelligence. Here, we sought to replicate this finding using five independent cohorts of older adults including current IQ and childhood IQ, and using both gene- and SNP-based analytic strategies. No significant associations were found between variation in heterotrimeric G protein genes and intelligence in any cohort at either of the two time points. These results indicate that, whereas G protein systems are important in cognition, common genetic variation in these genes is unlikely to be a substantial influence on human intelligence differences.
    PLoS ONE 01/2014; 9(3):e91690. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It has long been recognized that generalized deficits in cognitive ability represent a core component of schizophrenia (SCZ), evident before full illness onset and independent of medication. The possibility of genetic overlap between risk for SCZ and cognitive phenotypes has been suggested by the presence of cognitive deficits in first-degree relatives of patients with SCZ; however, until recently, molecular genetic approaches to test this overlap have been lacking. Within the last few years, large-scale genome-wide association studies (GWAS) of SCZ have demonstrated that a substantial proportion of the heritability of the disorder is explained by a polygenic component consisting of many common single-nucleotide polymorphisms (SNPs) of extremely small effect. Similar results have been reported in GWAS of general cognitive ability. The primary aim of the present study is to provide the first molecular genetic test of the classic endophenotype hypothesis, which states that alleles associated with reduced cognitive ability should also serve to increase risk for SCZ. We tested the endophenotype hypothesis by applying polygenic SNP scores derived from a large-scale cognitive GWAS meta-analysis (~5000 individuals from nine nonclinical cohorts comprising the Cognitive Genomics consorTium (COGENT)) to four SCZ case-control cohorts. As predicted, cases had significantly lower cognitive polygenic scores compared to controls. In parallel, polygenic risk scores for SCZ were associated with lower general cognitive ability. In addition, using our large cognitive meta-analytic data set, we identified nominally significant cognitive associations for several SNPs that have previously been robustly associated with SCZ susceptibility. Results provide molecular confirmation of the genetic overlap between SCZ and general cognitive ability, and may provide additional insight into pathophysiology of the disorder.Molecular Psychiatry advance online publication, 17 December 2013; doi:10.1038/mp.2013.166.
    Molecular psychiatry 12/2013; · 15.05 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate whether there is overlap in the genetic determinants of Type 2 diabetes and cognitive ageing by testing whether a genetic risk score for Type 2 diabetes can predict variation in cognitive function in older people without dementia. Type 2 diabetes genetic risk scores were estimated using various single nucleotide polymorphism significance inclusion criteria from an initial genome-wide association study, the largest in Type 2 diabetes to date. Scores were available for 2775-3057 individuals, depending on the cognitive trait. Type 2 diabetes genetic risk was associated with self-reported diabetes mellitus. Across varying single nucleotide polymorphism-inclusion levels, a significant association between Type 2 diabetes genetic risk and change in general cognitive function was found (median r=0.04); however, this was such that higher Type 2 diabetes genetic risk related to higher cognitive scores. To investigate more fully the source of the often observed comorbidity between Type 2 diabetes and cognitive impairment, one direction for future research will be to use cognitive ability polygenic risk scores to predict Type 2 diabetes in line with the reverse causation hypothesis that people with lower pre-morbid cognitive ability are more likely to develop Type 2 diabetes. This article is protected by copyright. All rights reserved.
    Diabetic Medicine 12/2013; · 3.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective To identify new genetic associations with juvenile and adult dermatomyositis (DM). Methods We performed a genome-wide association study (GWAS) of adult and juvenile DM patients of European ancestry (n = 1,178) and controls (n = 4,724). To assess genetic overlap with other autoimmune disorders, we examined whether 141 single-nucleotide polymorphisms (SNPs) outside the major histocompatibility complex (MHC) locus, and previously associated with autoimmune diseases, predispose to DM. ResultsCompared to controls, patients with DM had a strong signal in the MHC region consisting of GWAS-level significance (P < 5 × 10–8) at 80 genotyped SNPs. An analysis of 141 non-MHC SNPs previously associated with autoimmune diseases showed that 3 SNPs linked with 3 genes were associated with DM, with a false discovery rate (FDR) of
    Arthritis & Rheumatology 12/2013; 65(12). · 7.48 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Apolipoprotein E (ApoE) is the most well-described genetic risk factor for Alzheimer's disease and nonpathological cognitive decline. While possession of the E2 allele may have protective properties, substantial research evidence suggests the E4 allele increases the risk of cognitive degeneration. As neurodegenerative processes are implicated in swallowing dysfunction, we hypothesized that the presence of ApoE 4 would be predictive of dysphagia symptoms in older adults. Eight hundred members of a genetically well characterized community dwelling elderly cohort received the Sydney oropharyngeal dysphagia questionnaire via mail. Cognitive function was also measured using the modified Telephone Interview of Cognitive Status (TiCS-m) and depression with the Geriatric Depression Score (GDS). ApoE allele was genotyped on blood samples from all subjects and data analyzed using standard statistical software (SPSS version 16). Completed questionnaire response rate was 79% (23.5% men, 76.5% women; mean age 81 ± 5 years; range 69-98 years). Possession of one or more of the ApoE 4 and 2 alleles was found in 23.5% and 16%, respectively. Swallowing score was significantly related to GDS (rho 0.133, P < 0.001**) and age (rho 0.107, P < 0.007**) but not general cognitive function as measured by TICS-m. Self-reported swallowing function was not significantly associated with heterozygosity of any allele or homozygosity for E2 or E3 alleles. Although infrequent (1.1% of all subjects) ApoE E4 homozygosity was significantly associated with higher swallowing scores compared to all other allele combinations (P = 0.033) and while attenuated, was still predicted in multivariate regression modeling (B = 0.812; SE = 0.323; P = 0.012). We report the association between ApoE 4 homozygous genotype and self-reported oropharyngeal dysphagia symptoms in community-dwelling older adults. As this association is weakened by the multivariate analysis and the population frequency of ApoE 4 allele homozygosity is low, this finding while intriguing requires replication in larger independent cohorts.
    Diseases of the Esophagus 11/2013; · 1.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Alzheimer's disease (AD) and non-pathological cognitive aging have phenotypic similarities which may be influenced by an overlapping set of genetic variants. Genome-wide complex trait analysis estimates that common genetic variants account for about 24% of the variation contributing to liability for AD. It is also estimated that 24% of the variance of non-pathological cognitive aging is accounted for by common single nucleotide polymorphisms. However, although the APOE locus is associated with both AD and cognitive aging, it is not known to what extent other common genetic variants, with smaller effect sizes that influence both, overlap. We test the hypothesis that polygenic risk for AD is associated with cognitive ability and cognitive change in about 3,000 non-demented older people (Cognitive Ageing Genetics England and Scotland-CAGES-consortium). We found no significant association of polygenic risk for AD with cognitive ability or cognitive change in CAGES, indicating that the genetic etiologies of AD and non-pathological cognitive decline differ.
    Journal of Alzheimer's disease: JAD 11/2013; · 4.17 Impact Factor
  • Source
    Dataset: 6363780a
  • [Show abstract] [Hide abstract]
    ABSTRACT: The hypothesis of the study was that IGF2 gene polymorphisms were associated with longitudinal trends in weight through modification of IGF-II concentration.Observational study that explored associations of the IGF2 gene and baseline circulating IGF-II concentration with ‘real-world' longitudinal trends in body-mass index in a type 2 diabetes population.26 haplotype tagging single nucleotide polymorphisms (SNPs) from the IGF2 and H19 genes were studied in 485 Caucasian individuals in the Salford Longitudinal Diabetes Cohort. A generalised-estimating equation (GEE) model was used to separately study the association of SNPs and IGF-II concentration with 8-year longitudinal trends in body-mass index.High serum IGF-II concentration at baseline was associated with weight loss over the study period (β=-0.006, 95% CI -0.009 to -0.002, p<0.001). 8 SNPs were associated with longitudinal body-mass index trends, of which 4 retained significance after multiple -testing correction. 2 SNPs rs10770063 and rs3842767 were associated with both IGF-II concentration as well as longitudinal weight changes.We report novel associations between polymorphisms in the IGF2 gene, with concentration of circulating IGF-II and also with longitudinal weight change in type 2 diabetes. Our data indicate that the IGF2 gene and its gene product may be important determinants of longitudinal weight trends in type 2 diabetes.
    Experimental and Clinical Endocrinology & Diabetes 06/2013; 121(6):361-7. · 1.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Canine diabetes mellitus (DM) shares many similarities with human type 1 diabetes (T1D). It is a complex genetic disorder, which shows marked differences in breed susceptibility, with Samoyed dogs being highly susceptible, whereas the Boxer breed is relatively resistant. A number of immune response genes, which have been associated with human T1D, have also been implicated in determining susceptibility to canine DM, suggesting an immune-mediated component to the disease pathogenesis. Single nucleotide polymorphisms (SNPs) in the CTLA4 gene have consistently and reproducibly been associated with human T1D and other autoimmune diseases but the canine CTLA4 gene has not previously been investigated for involvement in canine DM. SNPs of particular interest in the human association studies are those in the promoter region which affect CTLA4 expression levels, and that of exon 1 which results in a non-synonymous amino acid change. We performed a canine SNP discovery investigation of CTLA4 on a region of DNA containing exon 1 and 1.5 kb upstream sequence in order to identify promoter region SNPs. Confirmed SNPs were used in a genetic association study of a canine diabetic cohort showing that CTLA4 promoter polymorphisms were associated with diabetes in crossbreed dogs and in five Pedigree breeds–Samoyed, Miniature Schnauzer, West Highland White Terrier, Border Terrier and Labrador. Meta-analysis of these breeds showed 9 out of 15 SNPs were associated with DM and genotype and haplotype analyses also confirmed the allelic associations in these breeds.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Digital dermatitis is a painful foot disease compromising welfare in dairy cattle. The disease has a complex multibacterial aetiology, but little is known about its pathogenesis. In this study, gene expression in skin biopsies from five bovine digital dermatitis lesions and five healthy bovine feet was compared using RNA-Seq technology. Differential gene expression was determined after mapping transcripts to the Btau 4.0 genome. Pathway analysis identified gene networks involving differentially expressed transcripts. Bovine digital dermatitis lesions had increased expression of mRNA for α2-macroglobulin-like 1, a protein potentially involved in bacterial immune evasion and bacterial survival. There was increased expression of keratin 6A and interleukin 1β mRNA in bovine digital dermatitis lesions, but reduced expression of most other keratin and keratin-associated genes. There was little evidence of local immune reactions to the bacterial infection present in lesions.
    The Veterinary Journal 04/2013; · 2.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: [This corrects the article on p. 95 in vol. 1.].
    Endocrine connections. 03/2013; 2(1):X1.

Publication Stats

11k Citations
2,161.11 Total Impact Points

Institutions

  • 1989–2014
    • The University of Manchester
      • • Centre for Integrated Genomic Medical Research (CIGMR)
      • • Institute of Cardiovascular Sciences
      • • Manchester Medical School
      Manchester, England, United Kingdom
    • ICL
      Londinium, England, United Kingdom
  • 2008–2013
    • The University of Edinburgh
      • • Department of Psychology
      • • Centre for Cognitive Ageing and Cognitive Epidemiology
      • • Royal (Dick) School of Veterinary Studies
      Edinburgh, Scotland, United Kingdom
  • 2001–2013
    • University of Liverpool
      • • Department of Infection Biology
      • • School of Veterinary Science
      Liverpool, ENG, United Kingdom
    • Humboldt-Universität zu Berlin
      • Department of Psychology
      Berlin, Land Berlin, Germany
    • Revmatologicky Ustav
      Praha, Praha, Czech Republic
    • Istanbul University
      • Department of Internal Medicine
      İstanbul, Istanbul, Turkey
  • 2012
    • Western General Hospital
      Edinburgh, Scotland, United Kingdom
  • 2011–2012
    • Wellcome Trust Sanger Institute
      Cambridge, England, United Kingdom
    • University of Oxford
      • Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS)
      Oxford, England, United Kingdom
    • Malawi-Liverpool-Wellcome Trust Clinical Research Programme
      Kapeni, Southern Region, Malawi
    • Central Manchester University Hospitals NHS Foundation Trust
      Manchester, England, United Kingdom
  • 2008–2012
    • Royal Veterinary College
      • • Department of Pathology and Infectious Diseases
      • • Department of Veterinary Clinical Sciences
      London, ENG, United Kingdom
  • 2009–2010
    • Jordan University of Science and Technology
      • Department of Oral Medicine and Oral Surgery
      Irbid, Irbid, Jordan
    • Salford Royal NHS Foundation Trust
      Salford, England, United Kingdom
    • Kerman University of Medical Sciences
      Carmana, Kermān, Iran
    • University of Pittsburgh
      • Division of Rheumatology and Clinical Immunology
      Pittsburgh, Pennsylvania, United States
  • 2007
    • Universidad de Cantabria
      Santander, Cantabria, Spain
    • Wrightington, Wigan and Leigh NHS Foundation Trust
      Wigan, England, United Kingdom
  • 2005
    • University of Southampton
      • Department of Psychology
      Southampton, ENG, United Kingdom
    • Tehran University of Medical Sciences
      • Endocrinology and Metabolism Research Center
      Tehrān, Ostan-e Tehran, Iran
  • 2003
    • University of Leeds
      • School of Biology
      Leeds, ENG, United Kingdom
  • 2002–2003
    • University of Wales
      • College of Medicine
      Cardiff, Wales, United Kingdom
    • Charles University in Prague
      Praha, Praha, Czech Republic
    • National Heart, Lung, and Blood Institute
      Maryland, United States
  • 1999–2002
    • Staffordshire and Stoke-On-Trent Partnership NHS Trust
      Newcastle-under-Lyme, England, United Kingdom
  • 1999–2001
    • Keele University
      • Institute for Science and Technology in Medicine
      Newcastle-under-Lyme, England, United Kingdom
  • 2000
    • Beirut Arab University
      • Faculty of Pharmacy
      Beirut, Mohafazat Beyrouth, Lebanon
    • King College
      Guymon, Oklahoma, United States
  • 1998
    • Hospital Central de Asturias
      Oviedo, Asturias, Spain
  • 1996–1998
    • Tokyo Medical and Dental University
      • • Department of Medicine
      • • Medical Research Institute
      • • Department of Internal Medicine
      Edo, Tōkyō, Japan
  • 1989–1998
    • Evangelismos Hospital
      Athínai, Attica, Greece
  • 1997
    • The Police Academy of the Czech Republic in Prague
      Praha, Praha, Czech Republic
    • Ahmadu Bello University
      • Department of Ophthalmology
      Zaria, Kaduna State, Nigeria
  • 1993–1995
    • University of California, San Diego
      • Department of Medicine
      San Diego, CA, United States
  • 1994
    • Cornell University
      Ithaca, New York, United States
    • Memorial University of Newfoundland
      St. John's, Newfoundland and Labrador, Canada
  • 1992
    • Manchester Memorial Hospital
      Manchester, Connecticut, United States
  • 1991
    • Saint Mary's Hospital Center
      Montréal, Quebec, Canada
  • 1988
    • London College of Clinical Hypnosis
      Londinium, England, United Kingdom