Search PubMed⌕ Search

Biomedical subjects

P O'Connor

Publications and source records attributed to P O'Connor.

At least 19 recordsLinked to original sources
PubMed2007

Sick notes, general practitioners, emergency departments and fracture clinics.

BACKGROUND: General practitioner waiting times are increasing. The two national surveys regarding general practice showed that the number of patients waiting for >or=2 days for an appointment rose from 63% to 72% between 1998 and 2002, with 25% waiting for >or=4 days. The Department of Health recognised that many patients discharged from hospitals and outpatient clinics required to visit their general practitioner for the sole purpose of obtaining a sick note. The report entitled Making a difference: reducing general practitioner paperwork estimated that 518 000 appointments (and 42 000 GP h) could be saved by ensuring that these patients were issued with a sick note directly from hospital rather than being referred to their general practitioner. This practice was to be adopted from July 2001 and included patients discharged from wards as well as those seen in outpatient departments. METHOD: 50 emergency departments and fracture clinics in Scotland and England were contacted to assess whether these guidelines had been adopted. Only hospitals with both accident and emergency and fracture clinics were included; nurse-led and paediatric departments were excluded. RESULTS: Of the 25 Scottish emergency hospitals contacted, 4 (16%) accident and emergency departments and 8 (32%) fracture clinics issued sick notes. This was compared with 5 of 25 (20%) accident and emergency departments and 12 of 25 (48%) fracture clinics in England. Four Scottish and five English accident and emergency departments stated that it was policy to give sick notes, three Scottish and four English departments said that it was policy not to give them and the rest (72% in Scotland and 64% in England) stated that they had no clear policy but "just don't give them". CONCLUSION: The 2001 guidance from the joint Cabinet Office/Department of Health has not been fully incorporated into standard practice in Scotland and England. If all emergency departments and fracture clinics were to issue sick notes to patients requiring >7 days absence from work, this could reduce general practitioner consultations and improve waiting times.

Emergency Service, Hospital↗
PubMed2006

Age at onset of multiple sclerosis may be influenced by place of residence during childhood rather than ancestry.

Multiple sclerosis (MS) most commonly affects individuals of Northern European descent who live in countries at high latitude. The relative contributions of ancestry, country of birth and residence as determinants of MS risk have been studied in adult MS, but have not been explored in the pediatric MS population. In this study, we compare the demographics of pediatric- and adult-onset MS patients cared for in Toronto, Ontario, Canada, a multicultural region. The country of birth, residence during childhood, and ancestry were compared for 44 children and 573 adults. Our results demonstrate that although both the pediatric and adult cohorts were essentially born and raised in the same region of Ontario, Canada, children with MS were more likely to report Caribbean, Asian or Middle Eastern ancestry, and were less likely to have European heritage compared with individuals with adult-onset MS. The difference in ancestry between the pediatric and adult MS cohorts can be explained by two hypotheses: (1) individuals raised in a region of high MS prevalence, but whose ancestors originate from regions in which MS is rare, have an earlier age of MS onset, and (2) the place of residence during childhood, irrespective of ancestry, determines lifetime MS risk -- a fact that will be reflected in a change in the demographics of the adult MS cohort in our region as Canadian-raised children of recent immigrants reach the typical age of adult-onset MS.

Adolescent↗
PubMed2005

The effect of strain of Holstein-Friesian cow and feeding system on postpartum ovarian function, animal production and conception rate to first service.

Three strains of Holstein-Friesian (HF): high production North American (HP), high durability North American (HD) and New Zealand (NZ) cows were assigned, within strain, to one of three pasture-based feeding systems: (1) the Moorepark (control) system (MP), (2) a high concentrate system (HC), (3) a high stocking rate system (HS). Ovarian function was assessed using milk progesterone samples, collected from 117 cows in each of two successive years, with 81 animals being common to both years. Milk samples were collected thrice weekly, beginning day 5 post-calving and continued to day 26 after first AI. Data from animals subsequent to reproductive hormonal treatment were removed from the analysis. Feed system and strain of HF by feeding system interaction had no significant effect on re-establishment of ovarian activity and subsequent conception rate to first AI. Strain of HF had no significant effect on interval to commencement of luteal activity (CLA). The mean interval to CLA was 32.9 days (S.E. 1.18), ranged from 6 to 100 days, with 42 and 85% of cows ovulating by day 26 and 60, respectively. The HD (62%) and NZ (57%) strains had a higher conception rate to first AI than the HP strain (40%), (P < 0.05). Retrospective analysis categorised all cows into four quartiles based on interval to CLA (< 20 days, 20-26 days, 27-44 days and > 44 days). Cows in the first and fourth CLA quartiles had a longer calving to conception interval (P < 0.05). Cows with abnormal progesterone profiles (38.4%) had an earlier mean calving date, with a similar submission rate and conception rate to first service compared to cows with normal hormonal profiles. There was no significant difference in luteal activity or reproduction performance, apart from calving to conception interval, between cows that conceived or did not conceive to first service. These results indicate that while conception rate to first service differed between strains of HF cow, this was not associated with differences in the onset and pattern of luteal activity post partum.

Animal Feed↗
PubMed2005

The development of the EULAR-OMERACT rheumatoid arthritis MRI reference image atlas.

Based on a previously developed rheumatoid arthritis MRI scoring system (OMERACT 2002 RAMRIS), the development team agreed which joints, MRI features, MRI sequences, and image planes would best illustrate the scoring system in an atlas. After collecting representative examples for all grades for each abnormality (synovitis, bone oedema, and bone erosion), the team met for a three day period to review the images and choose by consensus the most illustrative set for each feature, site, and grade. A predefined subset of images (for example, for erosion--all coronal slices through the bone) was extracted. These images were then re-read by the group at a different time point to confirm the scores originally assigned. Finally, all selected images were photographed and formatted by one centre and distributed to all readers for final approval.

Arthritis, Rheumatoid↗
PubMed2005

The EULAR-OMERACT rheumatoid arthritis MRI reference image atlas: the metacarpophalangeal joints.

This paper presents the metacarpophalangeal (MCP) joint magnetic resonance images of the EULAR-OMERACT rheumatoid arthritis MRI reference image atlas. The illustrations include synovitis in the MCP joints (OMERACT RA magnetic resonance imaging scoring system (RAMRIS), grades 0-3), bone oedema in the metacarpal head and the phalangeal base (grades 0-3), and bone erosion in the metacarpal head and the phalangeal base (grades 0-3, and examples of higher grades). The presented reference images can be used to guide scoring of MCP joints according to the OMERACT RA MRI scoring system.

Arthritis, Rheumatoid↗
PubMed2005

The EULAR-OMERACT rheumatoid arthritis MRI reference image atlas: the wrist joint.

This paper presents the wrist joint MR images of the EULAR-OMERACT rheumatoid arthritis MRI reference image atlas. Reference images for scoring synovitis, bone oedema, and bone erosions according to the OMERACT RA MRI scoring (RAMRIS) system are provided. All grades (0-3) of synovitis are illustrated in each of the three wrist joint areas defined in the scoring system--that is, the distal radioulnar joint, the radiocarpal joint, and the intercarpal-carpometacarpal joints. For reasons of feasibility, examples of bone abnormalities are limited to five selected bones: the radius, scaphoid, lunate, capitate, and a metacarpal base. In these bones, grades 0-3 of bone oedema are illustrated, and for bone erosion, grades 0-3 and examples of higher grades are presented. The presented reference images can be used to guide scoring of wrist joints according to the OMERACT RA MRI scoring system.

Arthritis, Rheumatoid↗
PubMed2005

Pitfalls in scoring MR images of rheumatoid arthritis wrist and metacarpophalangeal joints.

This paper outlines the most important pitfalls which are likely to be encountered in the assessment of magnetic resonance images of the wrist and metacarpophalangeal joints in patients with rheumatoid arthritis. Imaging artefacts and how these can be recognised using various sequences and views are discussed. Normal structures such as interosseous ligaments and nutrient foramina may appear prominent on certain images and need to be identified correctly. Pathological change in the rheumatoid hand involves many tissues and when substantial damage has occurred, it may be difficult to identify individual structures correctly. Bone erosion, bone oedema, synovitis, and tenosynovitis frequently occur together and in close proximity to each other, potentially leading to false positive scoring of any of these. Examples are given to illustrate the various dilemmas the user of this atlas may face when scoring the rheumatoid hand and suggestions are made to assist correct interpretation of what can be very complex images.

Arthritis, Rheumatoid↗
PubMed2005

Randomized study of once-weekly interferon beta-1la therapy in relapsing multiple sclerosis: three-year data from the OWIMS study.

BACKGROUND: Once weekly interferon beta-1a for multiple sclerosis (OWIMS) demonstrated modest, but significant, magnetic resonance imaging (MRI) benefit of once-weekly (qw) interferon (IFN) beta-1a at 48 weeks, but no significant effect on relapses. OBJECTIVE: An OWIMS extension permitted assessment of longer-term efficacy/safety of qw IFN beta-1a in relapsing-remitting multiple sclerosis (RRMS). METHODS: Placebo patients were rerandomized to IFN beta-1a, 22 or 44 mcg qw, for two additional 48-week intervals. Primary outcome was MRI lesion activity. Relapse rate and other MRI measures were secondary outcomes. RESULTS: After three years, median (mean) T2 lesion count/patient/scan was 1.3 (2.6) for 44 mcg, 1.7 (3.3) for 22 mcg, 1.7 (3.4) for placebo/22 mcg, 2.0 (3.6) for placebo/44 mcg (all differences not significant). Annualized relapse rates were lowest for 44 mcg (0.77) versus other groups (0.83-0.86, not significant). Persistent neutralizing antibodies did not affect relapse rates, but MRI active lesions were increased in antibody-positive patients receiving 44 mcg compared to antibody negative patients. CONCLUSIONS: In RRMS, once weekly IFN beta-1a, particularly 44 mcg, can induce a significant MRI, but not relapse, effect, compared with placebo. No significant dose effect was seen. In contrast to the significant effect observed with three-times-weekly dosing of subcutaneous IFN beta-1a compared with placebo, this study confirms the lack of meaningful clinical benefit with once-weekly dosing.

Adjuvants, Immunologic↗
PubMed2005

MRI results from the European Study on Intravenous Immunoglobulin in Secondary Progressive Multiple Sclerosis (ESIMS).

BACKGROUND: Monthly application of high-dose intravenous immunoglobulin (IVIG) to patients with secondary progressive multiple sclerosis (MS) showed no clinical benefit in the European Study on Immunoglobulin in MS (ESIMS). Magnetic resonance imaging (MRI) results may provide insights into the morphologic consequences of such treatment. METHODS: A total of 318 patients (mean age 44 +/- 7 years) were enrolled in 31 European and Canadian centres and treated monthly with 1 g/kg body weight of IVIG or equivalent amounts of albumin 0.1% for 27 months. MRI was performed at baseline and after 12 and 24 months and comprised of conventional dual-echo T2-weighted and T1-weighted scans before and after application of 0.1 mmol/kg Gd-DTPA. RESULTS: Similar to clinical variables, MRI measures at baseline were well comparable between treatment groups except for a somewhat lower mean number of contrast-enhancing lesions and number of active scans in IVIG-treated patients. Over the trial period there was almost no change of the T2-lesion load and the 'black hole' volume in both treatment groups and the cumulative number of contrast-enhancing lesions were similar. There was only a trend for fewer new or enlarged T2-lesions in IVIG patients, which disappeared after correction for the imbalance in the number of contrast-enhancing lesions at baseline. Brain volume in terms of a partial cerebral fraction decreased significantly less with IVIG than placebo treatment (final visit: -0.62 -/+ 0.88% versus -0.88 +/- 0.91%; P=0.009). This difference remained statistically significant with correction for active lesions at baseline (P=0.02) and was seen primarily in male patients and those with an Expanded Disability Status Scale score > or = 6 and no relapses in the two years before the study. CONCLUSION: The absence of significant differences in conventional MRI measures between both treatment groups parallels the negative clinical results of ESIMS. The causes for and possible long-term clinical effects of a lower rate of brain volume loss in IVIG patients should be explored further.

Adult↗
PubMed2004

Efficacy of anakinra in active ankylosing spondylitis: a clinical and magnetic resonance imaging study.

OBJECTIVE: To determine the efficacy of anakinra, an interleukin 1 receptor antagonist in active ankylosing spondylitis (AS), and to investigate the effect of anakinra treatment on spinal enthesitis/osteitis using magnetic resonance imaging (MRI). METHODS: A 3 month open label study of anakinra (100 mg subcutaneous injection daily) was carried out in nine patients with active AS who had back pain and an increased acute phase response, and who had failed to respond to at least one non-steroidal anti-inflammatory drug. Clinical assessment included the Bath AS Functional Index (BASFI), Bath AS Disease Activity Index (BASDAI), and AS Quality of Life (ASQoL) before and after treatment. Fat suppressed MRI of the spine and sacroiliac joints was performed with a 1.5 T scanner at baseline and at 3 months to determine the effect of treatment on spinal enthesitis/osteitis. RESULTS: Significant improvement was found in the BASFI (median baseline 5.88, 3 months 3.63, p = 0.021), BASDAI (median baseline 5.63, 3 months 3.48, p = 0.028), ASQoL (median baseline 12, 3 months 8, p = 0.011) and laboratory measures reflecting inflammation, with C reactive protein (median baseline 31 mg/l, 3 months 17 mg/l, p = 0.036) and erythrocyte sedimentation rate (median baseline 19 mm/1st h, 3 months 15 mm/1st h, p = 0.008) also showing significant improvement. Six patients (67%) achieved the Assessments in AS (ASAS) Working Group criteria of 20% improvement. Of the 38 regions of enthesitis/osteitis determined by MRI at baseline, 23 (61%) either improved or regressed completely. CONCLUSIONS: This open label pilot study suggests that anakinra is effective in controlling the clinical manifestations of AS. The clinical response was reflected by an improvement in MRI determined spinal enthesitis/osteitis.

Adult↗
PubMed2004

Structural brain abnormalities in multiple sclerosis patients with major depression.

OBJECTIVE: To assess the association between major depression and structural brain abnormalities in patients with multiple sclerosis (MS). METHODS: Two groups of patients with clinically definite MS were studied: 21 with Diagnostic and Statistical Manual of Mental Disorders (4th ed.)-defined major depression and 19 without. The groups did not differ on demographic, disease, or cognitive measures. All subjects underwent brain MRI. Tissue segmentation and regional brain masking were applied to the MRI data. RESULTS: Compared with the euthymic subjects, those with major depression had a greater T2-weighted lesion volume (p = 0.003) and more extensive T1-weighted lesion volume in the left medial inferior prefrontal cortex (p = 0.01) and less gray matter volume (p = 0.01) and more CSF volume in the left anterior temporal region (p = 0.005). A logistic regression analysis identified two independent predictors of depression: left medial inferior prefrontal cortex T2 lesion volume and left anterior temporal CSF volume. These variables accounted for 42% of the depression variance score. CONCLUSION: Whereas both lesion burden and atrophy are important in the pathogenesis of depression in MS, psychosocial influences should also be considered.

Adult↗
PubMed2004

Validation and reproducibility of ultrasonography in the detection of synovitis in the knee: a comparison with arthroscopy and clinical examination.

OBJECTIVE: Accurate detection of synovitis is important in both the diagnosis and outcome assessment of arthritis. This study was undertaken to assess the validity and reproducibility of ultrasonography (US) as a means of detecting synovitis in the knee, by comparing US findings with findings of arthroscopy and clinical examination. METHODS: Sixty consecutive patients with knee pain due to various arthritides had a clinical examination and US of their knee performed immediately prior to arthroscopy. All 3 assessments were performed by different clinicians who were blinded to the results obtained with the other modalities. US and clinical examination were compared with arthroscopically detected synovitis as the gold standard. Data from a subset of patients were used for calculating the inter- and intrareader reproducibility of US results, using a standard dichotomous (absence/presence of synovitis) as well as a graded (absence/grade of synovitis) scoring system. RESULTS: With the use of arthroscopy as the gold standard, US had a higher sensitivity (98% versus 85%), specificity (88% versus 25%), accuracy (97% versus 77%), positive predictive value (98% versus 88%), and negative predictive value (88% versus 20%) compared with clinical examination. The Cohen kappa values for inter- and intrareader reproducibility of US for distinguishing between presence and absence of synovitis were 0.71 and 0.85, respectively (P < 0.05 for both). The weighted kappa values for distinguishing grade of synovitis were 0.65 for inter- and 0.74 for intrareader reproducibility. The kappa value for intrareader reproducibility of arthroscopy results was 0.88. CONCLUSION: Ultrasonography is a valid and reproducible technique for detecting synovitis in the knee, and is more accurate than clinical examination. It may be valuable as a tool in studies investigating pain, diagnosis, and treatment response in knee arthritis.

Adolescent↗
PubMed2003

Enhanced optical emission during Crab giant radio pulses.

We detected a correlation between optical and giant radio pulse emission from the Crab pulsar. Optical pulses coincident with the giant radio pulses were on average 3% brighter than those coincident with normal radio pulses. Combined with the lack of any other pulse profile changes, this result indicates that both the giant radio pulses and the increased optical emission are linked to an increase in the electron-positron plasma density.

Journal Article↗
PubMed2003

Identical twins discordant for multiple sclerosis have a shift in their T-cell receptor repertoires.

CD4 T-cells have an important role in the autoimmune response in multiple sclerosis (MS). We investigate the possibility that a shift occurs in the T-cell receptor (TR) repertoire of identical twins discordant for MS. We compare the CDR3 spectratype distributions of 24 different TR V beta (TRBV) segments in naïve CD4 T-cells from discordant MS twins and from healthy identical twins. We also compare the CDR3 spectratype distributions in unrelated healthy pairs, formed by combining members of different healthy twins, with the CDR3 spectratype distributions in unrelated pairs of MS patients and in unrelated pairs of their apparently healthy cotwins, formed by combining members of different discordant twins. We use the correlation coefficient (r-value) as a measure of similarity of CDR3 spectratypes in each pair, and we test for the significance of the difference between r-values from the different pairs. We observe that the r-value for the CDR3 spectratype distributions among discordant twins differs significantly from the corresponding r-value for the healthy twins for two TRBV segments. Further, the r-values, for both the unrelated MS patient pairs and the unrelated pairs of their apparently healthy cotwins, differ significantly from the r-values for healthy unrelated pairs of individuals. We conclude that both the MS patients and their apparently healthy cotwins have shifts in their CDR3 repertoires. Because we study naïve CD4 T-cells, we postulate that CDR3 repertoire shifts precede MS and predispose to MS, but are unlikely to be sufficient to cause MS.

Adult↗
PubMed2003

Efficacy of etanercept for treatment of Crohn's related spondyloarthritis but not colitis.

The seronegative spondyloarthropathies (SpAs) are associated both with clinical and subclinical colitis. Recently biological blockade with the tumour necrosis factor alpha (TNFalpha) antagonists infliximab and etanercept has been shown to be effective in the treatment of SpA. However, only infliximab is efficacious in the treatment of colitis in patients with Crohn's SpA. We report on two patients with SpA and associated Crohn's disease treated with etanercept whose arthritis showed an excellent response with complete resolution of spinal pathology, whereas their Crohn's disease persisted or flared. These findings suggest that the effect of TNFalpha blockade in SpA differs between the joint and the bowel.

Adult↗
PubMed2002

Randomized, comparative study of interferon beta-1a treatment regimens in MS: The EVIDENCE Trial.

BACKGROUND: Interferon beta (IFNbeta) reduces relapses and MRI activity in relapsing-remitting MS (RRMS), with variable effects on disability. The most effective dose regimen remains controversial. METHODS: This randomized, controlled, multicenter trial compared the efficacy and safety of IFNbeta-1a (Rebif) 44 micro g subcutaneously three times weekly (tiw), and IFNbeta-1a (Avonex) 30 micro g IM once weekly (qw) in 677 patients with RRMS. Assessors blinded to treatment performed neurologic and MRI evaluations. The primary endpoint was the proportion of patients who were relapse free at 24 weeks; the principal MRI endpoint was the number of active lesions per patient per scan at 24 weeks. RESULTS: After 24 weeks, 74.9% (254/339) of patients receiving IFNbeta-1a 44 micro g tiw remained relapse free compared with 63.3% (214/338) of those given 30 micro g qw. The odds ratio for remaining relapse free was 1.9 (95% CI, 1.3 to 2.6; p = 0.0005) at 24 weeks and 1.5 (95% CI, 1.1 to 2.1; p = 0.009) at 48 weeks, favoring 44 micro g tiw. Patients receiving 44 micro g tiw had fewer active MRI lesions (p < 0.001 at 24 and 48 weeks) compared with those receiving 30 micro g qw. Injection-site reactions were more frequent with 44 micro g tiw (83% vs 28%, p < 0.001), as were asymptomatic abnormalities of liver enzymes (18% vs 9%, p = 0.002) and altered leukocyte counts (11% vs 5%, p = 0.003) compared with the 30 micro g qw dosage. Neutralizing antibodies developed in 25% of 44 micro g tiw patients and in 2% of patients receiving 30 micro g qw. CONCLUSIONS: IFNbeta-1a 44 micro g subcutaneously tiw was more effective than IFNbeta-1a 30 micro g IM qw on all primary and secondary outcomes investigated after 24 and 48 weeks of treatment.

Adolescent↗
PubMed2002

A rapid ELISA-based serum assay for myelin basic protein in multiple sclerosis.

We have developed a sensitive, ELISA-based assay to detect autoantibodies to myelin basic protein (MBP) in human serum. Autoantibody levels were measured in 98 normal healthy adults (age range 20-66) and 94 clinically definite multiple sclerosis (MS) cases (age range 18-63). Of the MS patients, 77% had elevated levels of MBP autoantibodies (IgG) whereas only five normal individuals had antibody levels increased over normal. From the receiver-operator curve (ROC), the mean+/-2SD as clinical decision limit offers high sensitivity (77%) and specificity (95%). No change in assay performance was observed when hemoglobin, triglycerides or bilirubin were added to serum samples. The success of the assay is dependent on the use of heparin, an anionic molecule, which neutralizes the positive charge on the highly cationic MBP.

Adolescent↗