PubMed Health⌕ Search

Biomedical subjects

L Bradbury

Publications and source records attributed to L Bradbury.

11 recordsLinked to original sources

Non-B27 MHC associations of ankylosing spondylitis.

Ankylosing spondylitis (AS) has been associated with human leukocyte antigen (HLA)-B27 for over 30 years; however, the mechanism of action has remained elusive. Although many studies have reported associations between AS and other genes in the major histocompatibility complex (MHC) in AS, no conclusive results have emerged. To investigate the contribution of non-B27 MHC genes to AS, a large cohort of AS families and controls were B27 typed and genotyped across the region. Interrogation of the data identified a region of 270 kb, lying from 31 952 649 to 32 221 738 base pairs from the p-telomere of chromosome 6 and containing 23 genes, which is likely to include genes involved with susceptibility to AS.

Case-Control Studies↗

The effect of transforming growth factor beta1 gene polymorphisms in ankylosing spondylitis.

OBJECTIVES: To determine whether genetic polymorphisms in or near the transforming growth factor beta1 (TGFB1) locus were associated with susceptibility to or severity of ankylosing spondylitis (AS). METHODS: Five intragenic single-nucleotide polymorphisms (SNP) and three microsatellite markers flanking the TGFB1 locus were genotyped. Seven hundred and sixty-two individuals from 184 multiplex families were genotyped for the microsatellite markers and two of the promoter SNPs. One thousand and two individuals from 212 English and 170 Finnish families with AS were genotyped for all five intragenic SNPs. A structured questionnaire was used to assess the age of symptom onset, disease duration and disease severity scores, including the BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) and BASFI (Bath Ankylosing Spondylitis Functional Index). RESULTS: A weak association was noted between the rare TGFB1 +1632 T allele and AS in the Finnish population (P = 0.04) and in the combined data set (P = 0.03). No association was noted between any other SNPs or SNP haplotype and AS, even among those families with positive non-parametric linkage scores. The TGFB1 +1632 polymorphism was also associated with a younger age of symptom onset (English population, allele 2 associated with age of onset greater by 4.2 yr, P = 0.05; combined data set, allele 2 associated with age of onset greater by 3.2 yr, P = 0.02). A haplotype of coding region SNPs (TGFB1 +869/+915+1632 alleles 2/1/2) was associated with age of symptom onset in both the English parent-case trios and the combined data set (English data set, haplotype 2/1/2 associated with age of onset greater by 4.9 yr, P = 0.03; combined data set, haplotype 2/1/2 associated with greater age of onset by 4.2 yr, P = 0.006). Weak linkage with AS susceptibility was noted and the peak LOD score was 1.3 at distance 2 cM centromeric to the TGFB1 gene. No other linkage or association was found between quantitative traits and the markers. CONCLUSION: This study suggests that the polymorphisms within the TGFB1 gene play at most a small role in AS and that other genes encoded on chromosome 19 are involved in susceptibility to the disease.

Adult↗

Investigation of the role of ANKH in ankylosing spondylitis.

OBJECTIVE: The ank/ank mouse develops a phenotype similar to ankylosing spondylitis (AS) in humans. ANKH, the human homolog of the mutated gene in the ank/ank mouse, has been implicated in familial autosomal-dominant chondrocalcinosis and autosomal-dominant craniometaphyseal dysplasia. This study was undertaken to investigate the role of ANKH in susceptibility to and clinical manifestations of AS. METHODS: Sequence variants were identified by genomic sequencing of the 12 ANKH exons and their flanking splice sites in 48 AS patients; variants were then screened in 233 patients and 478 controls. Linkage to the ANKH locus was assessed in 185 affected-sibling-pair families. RESULTS: Five single-nucleotide polymorphisms were identified within the coding region and flanking splice sites. No association between either susceptibility to AS or its clinical manifestations and these novel polymorphisms, or between disease susceptibility and 3 known promoter variants, was seen. No linkage between the ANKH locus and AS was observed. Multipoint exclusion mapping rejected the hypothesis of a locus of a magnitude lambda>/=1.4 (logarithm of odds score <-2) (equivalent to a genetic contribution of >10% to the AS sibling recurrence risk ratio) within this area contributing to AS. CONCLUSION: These findings indicate that ANKH is not significantly involved in susceptibility to or clinical manifestations of AS.

Adult↗

Genetic testing for haemochromatosis in patients with chondrocalcinosis.

Hereditary haemochromatosis (HH) is the most common lethal monogenic human disease, affecting roughly 1 in 300 white northern Europeans. Homozygosity for the C282Y polymorphism within the HFE gene causes more than 80% of cases, with compound heterozygosity of the C282Y and H63D polymorphism also increasing susceptibility to disease. The aim of this study was to determine the frequency of the C282Y and H63D polymorphisms in the disease, and to assess the risk of HH in heterozygotes for the C282Y polymorphism. 128 patients were recruited because of either radiographic chondrocalcinosis (at least bicompartmental knee disease or joints other than the knee involved) or CPPD pseudogout. Genotyping of the HFE C282Y and H63D mutations was performed using PCR/SSP and genotypes for the C282Y polymorphism confirmed by PCR/RFLP. Historical white European control data were used for comparison. Two previously undiagnosed C282Y homozygotes (1.6%), and 16 C282Y heterozygotes (12.5%), including four (3.1%) C282Y/H63D compound heterozygotes were identified. This represents a significant overrepresentation of C282Y homozygotes (relative risk 3.4, p=0.037), but the number of heterozygotes was not significantly increased. At a cost per test of pound1 for each subject, screening all patients with chondrocalcinosis using the above ascertainment criteria costs only pound64 for each case of haemochromatosis identified, clearly a highly cost effective test given the early mortality associated with untreated haemochromatosis. Routine screening for haemochromatosis in patients with appreciable chondrocalcinosis is recommended.

Adult↗

Did exclusive breast-feeding and early discharge lead to excessive bilirubin levels in newborns in Antigua and Barbuda?

Hyperbilirubinaemia is a common neonatal problem worldwide and is the leading cause of admission to the Special Care Nursery in Antigua and Barbuda. In 1990, the Innocenti Declaration in support of breast-feeding led to the adoption of the Baby-Friendly Hospital Initiative in many countries of the Caribbean, including Antigua and Barbuda. Comparing 1989 to the years 1992 to 1994, the Special Care Nursery at Holberton Hospital experienced a 40% increase in newborns admitted with hyperbilirubinaemia (peak total bilirubin > 12 mg/dl or 205 mumol/l). A retrospective review of Special Care Nursery and Maternity Ward records was undertaken to determine the incidence and aetiology of hyperbilirubinaemia from 1992 to 1994. There were 3721 infants born in Antigua and Barbuda in those years, 98% of Afro-Caribbean or mixed ancestry. The overall incidence of peak total bilirubin over 12 mg/dl (205 mumol/l) was 12.5% (466/3721), not inconsistent with the reported incidence of 8 to 20% in other countries. However, the incidence of higher levels of hyperbilirubinaemia in Antigua and Barbuda exceeded those reported for other countries. In Antigua and Barbuda, total bilirubin of 15 mg/dl (255 mumol/l) or higher was found in 263 of 3721 infants (7.1%) compared to 5.9% in India and 2% of breast-fed infants in the United States of America (USA). Total bilirubin of 20 mg/dl (340 mumol/l) or higher was seen in 91 of 3721 infants (2.5%) exceeding reported prevalence in the USA for both African-American and Caucasian infants (1%) and equal to the reported prevalence in Asian infants (2%). The possible aetiologies of hyperbilirubinaemia in neonates with total bilirubin 18 mg/dl (306 mumol/l) or higher in our patients were investigated. Medical records of 134 of 156 (86%) infants having this level of hyperbilirubinaemia were available for review. The possible reason for hyperbilirubinaemia was ABO incompatibility in 4/134 (3%), Rh incompatibility in 1/134 (1%), prematurity in 12/134 (9%) and sepsis neonatorum in 21/134 (16%). The hyperbilirubinaemia was idiopathic in 96/134 (71%) infants. Newborns in Antigua and Barbuda were discharged 3.7 days after their mothers' admission, with 50% discharged prior to 48 hours of age. Early discharge in developed countries has led to increased readmissions for hyperbilirubinaemia. Following the appointment of a dietitian to supervise breast-feeding, admissions for hyperbilirubinaemia fell by 50% by 1998. These data suggest that exclusive breast-feeding and early discharge led to an epidemic of neonatal hyperbilirubinaemia in Antigua and Barbuda.

Antigua and Barbuda↗

Whole-genome screening in ankylosing spondylitis: evidence of non-MHC genetic-susceptibility loci.

Ankylosing spondylitis (AS) is a common inflammatory arthritis predominantly affecting the axial skeleton. Susceptibility to the disease is thought to be oligogenic. To identify the genes involved, we have performed a genomewide scan in 185 families containing 255 affected sibling pairs. Two-point and multipoint nonparametric linkage analysis was performed. Regions were identified showing "suggestive" or stronger linkage with the disease on chromosomes 1p, 2q, 6p, 9q, 10q, 16q, and 19q. The MHC locus was identified as encoding the greatest component of susceptibility, with an overall LOD score of 15.6. The strongest non-MHC linkage lies on chromosome 16q (overall LOD score 4.7). These results strongly support the presence of non-MHC genetic-susceptibility factors in AS and point to their likely locations.

Chromosome Mapping↗

Is disease severity in ankylosing spondylitis genetically determined?

OBJECTIVE: To assess the role of genes and the environment in determining the severity of ankylosing spondylitis. METHODS: One hundred seventy-three families with >1 case of ankylosing spondylitis were recruited (120 affected sibling pairs, 26 affected parent-child pairs, 20 families with both first- and second-degree relatives affected, and 7 families with only second-degree relatives affected), comprising a total of 384 affected individuals. Disease severity was assessed by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and functional impairment was determined using the Bath Ankylosing Spondylitis Functional Index (BASFI). Disease duration and age at onset were also studied. Variance-components modeling was used to determine the genetic and environmental components contributing to familiality of the traits examined, and complex segregation analysis was performed to assess different disease models. RESULTS: Both the disease activity and functional capacity as assessed by the BASDAI and the BASFI, respectively, were found to be highly familial (BASDAI familiality 0.51 [P = 10(-4)], BASFI familiality 0.68 [P = 3 x 10(-7)]). No significant shared environmental component was demonstrated to be associated with either the BASDAI or the BASFI. Including age at disease onset and duration of disease as covariates made no difference in the heritability assessments. A strong correlation was noted between the BASDAI and the BASFI (genetic correlation 0.9), suggesting the presence of shared determinants of these 2 measures. However, there was significant residual heritability for each measure independent of the other (BASFI residual heritability 0.48, BASDAI 0.36), perhaps indicating that not all genes influencing disease activity influence chronicity. No significant heritability of age at disease onset was found (heritability 0.18; P = 0.2). Segregation studies suggested the presence of a single major gene influencing the BASDAI and the BASFI. CONCLUSION: This study demonstrates a major genetic contribution to disease severity in ankylosing spondylitis. As with susceptibility to ankylosing spondylitis, shared environmental factors play little role in determining the disease severity.

Adolescent↗

Randomized placebo controlled trial of lofexidine hydrochloride for chronic pelvic pain in women.

BACKGROUND: We hypothesised that the orally-active alpha(2)-adrenoceptor agonist lofexidine hydrochloride would ameliorate chronic pelvic pain in women. METHODS: A randomized placebo-controlled parallel group trial was undertaken in the University Hospital Gynaecology Clinic. Women with pelvic pain of at least 6 months duration were eligible, and were randomized using a sealed envelope system to receive up to 600 mg lofexidine hydrochloride twice daily over 8 weeks or placebo. Outcome measures were summary and daily diary visual analog scales for pain (VAS) and a 5 point self rating scale. RESULTS: 9/19 women randomized to lofexidine completed the study compared to 14/20 of those randomized to placebo. Intention-to-treat analysis showed that 4/19 in the lofexidine group achieved 50% or greater reduction in VAS compared with 8/20 in the placebo group (OR 2.5, 95% CI 0.6--10.3). Summary and diary VAS were closely correlated. CONCLUSIONS: Within the limits of a small study with power to detect only a substantial effect, we conclude that lofexidine hydrochloride is not effective for the treatment of chronic pelvic pain.

Acetaminophen↗

Inflammatory eye, skin, and bowel disease in spondyloarthritis: genetic, phenotypic, and environmental factors.

OBJECTIVE: To explore the nature of the interrelationship between inflammatory disease of the spine/joints, skin, eye, and bowel [i.e., ankylosing spondylitis (AS), psoriasis, iritis, inflammatory bowel disease (IBD)]. METHODS: The study used 4 approaches: (1) analysis of the prevalence of secondary disorders within the AS individual (chi-square and matched pair analysis); (2) study of the temporal relationship between the onset of the different conditions; (3) evaluation of the prevalence of disease among first degree relatives; and (4) influence of secondary disorders on outcome of AS. RESULTS: 1. Among 3287 patients with AS, more than expected had either spondylitis associated with multiple co-disorders or pure AS (with no co-diseases); fewer than expected had AS plus a single co-disease (chi-square = 32.2, p < 0.001). In a matched pair analysis, patients with AS and a secondary disorder were more likely to have an additional concomitant disease, e.g., IBD-AS (n = 335) patients had a higher prevalence of iritis [45.4% vs 36.7%; OR 1.4 (1.1-2.0)] or psoriasis [23.9% vs 14.3%; OR 1.9 (1.3-2.8)] than controls. 2. Among our database subjects, the symptomatic onset of the spinal disease precedes or is contemporaneous with gut, skin, and eye involvement (matched pair t test, p < 0.001). 3. Patients with multiple disorders predict the highest prevalence of co-diseases (i.e., psoriasis, IBD, iritis, or AS) within family members, followed by those AS patients with only IBD, psoriasis, or iritis in descending order. 4. Both psoriasis and IBD increase severity in terrms of function and disease activity of AS in the patient. Radiological change is greatest for those AS subjects with iritis. CONCLUSION: There is a striking overlap within patients and family members of rheumatological, dermatological, and gastroenterological diseases. The susceptibility genes of these co-disorders appear to overlap with each other and with AS: 1. A patient with 2 inflammatory conditions is at an increased risk of developing an additional related inflammatory disorder. 2. Those with enteropathic spondylarthritis would appear to carry the greatest genetic load in terms of first degree relatives developing inflammatory conditions (including psoriasis and iritis that are not seen in the index IBD-AS patient). 3. The secondary disorders do not precede AS (arguing against psoriasis and IBD allowing for an environmental conduit to pathogenic triggers in AS). The susceptibility factors for these inflammatory conditions may be additive or have a synergistic effect on each other. There is evidence for a shared gene hypothesis.

Age of Onset↗

Disaster: the helper's perspective.

The responses to disaster and death vary enormously, but there is much to suggest that they are not confined to those who are directly affected. The helpers, too, may be "victims" of the disaster, and it is important that their psychological needs are perceived and met. There is an indication that, if this is done, considerable psychological morbidity may be prevented.

Disasters↗