Osteoporotic fracture admissions compared to other major medical admissions in Irish public hospitals

Multinational reports suggest Ireland has one of the greatest illness burdens related to osteoporosis. Hospital care represents the costliest portion of health services. We found public hospital bed days for fragility fractures in Ireland increased by 43% between 2008 and 2017 which exceeded those for other common diseases.

INTRODUCTION

Recent multinational reports suggest Ireland has one of the greatest illness burdens related to osteoporosis, manifesting clinically as fragility fractures (FF). International reports show that FF incidence, rate of hospital admission and cost are similar or greater than those for breast cancer, myocardial infarction and stroke. Studies addressing the illness burden of osteoporosis in Ireland are few, and none compares fragility fractures to other common chronic diseases.

METHODS

A retrospective analysis of national administrative data for all public hospital admissions was performed on adults aged 50 years and older from January 2008 to December 2017.

RESULTS

In 2017, public hospital bed days for FF totalled 249,887 outnumbering Chronic Obstructive Pulmonary Disease (COPD): 131,897; 6 solid cancers (CA): 118,098; myocardial infarction (MI): 83,477; and diabetes mellitus (DM): 31,044. Bed days for FF increased by 43% between 2008 and 2017, in contrast to a 32%, 28% and 31% reduction for CA, MI and DM, respectively, and a 12% increase for COPD. Public hospital bed days for FF in 2016 were greater than MI, stroke, atrial fibrillation and chest pain combined but less than a combination of COPD, pneumonia and lower respiratory tract infection.

CONCLUSION

Osteoporotic fractures represent a large and rapidly increasing illness burden amongst older Irish adults, with substantial care requirements and the resulting onus on our healthcare system. Urgent action is needed to address this public health issue and the services for those at risk of fracture.

A Unusual Case of Classic Hodgkin Lymphoma (cHL) with Aberrant T-Antigens Expression

Introduction/Objective

T-cell-associated antigens (TCA) are rarely expressed by Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) and is associated with uncertain clinical significance.

Methods/Case Report

We present a very recent case of a 68 year-old female with no significant past medical history presented with a large right groin mass for 1 month. She denied any fever, night sweats, fatigue or weight loss. CT abdomen/pelvis showed inguinal/pelvic lymphadenopathy. Resection showed effaced nodal architecture with a vague nodular appearance and with large, atypical nucleolated cells in a background of small, mature lymphocytes and histiocytes. Eosinophils are conspicuously absent in the background. The large cells were polylobated lymphocyte and histiocyte rich (L & H) like, classic HRS cells as well as multinucleated in appearance. The morphologic features overlapped between Classic Hodgkin Lymphoma, and Nodular Lymphocyte Predominant Hodgkin Lymphoma. Given the immunohistochemical (IHC) features of the neoplastic cells [CD45 negative, PAX5+ (weak), CD30+ (strong), CD15+ (majority) and MUM1 +] the diagnosis was most compatible with CHL. Interestingly, a subset of the Hodgkin cells (10-20%) aberrantly expressed a number of T-cell markers (CD2, CD3, CD4, and CD8). However, the background smaller T-cells did not show cytologic atypia or aberrancies of T-cell antigen markers. The large cells were negative for CD43 and ALK1. TCR gamma gene rearrangement was also negative for clonal T-lymphocytes, thus excluding the possibility of peripheral T-cell lymphoma with Hodgkin-like cells. Based on the morphology and IHC profile, this case proves to be CHL with multiple TCA expression including CD2, CD3, CD4 and CD8. She was planned for chemotherapy. Four months after the initial diagnosis and after completion of 2 cycles of chemotherapy, her PET CT scan showed improvement with right inguinal adenopathy being smaller in size and decreased avidity, indicating a response to treatment. She is due for 2 more cycles. Till todate she is doing well with no further symptoms.

Results (if a Case Study enter NA)

NA.

Conclusion

So far reported cases of classic Hodgkin lymphoma (CHL) with aberrant T-cell antigen (TCA) expression were associated with decreased event-free survival and overall survival when compared with TCA-negative CHLs. Our finding contributes to the literature and improves our knowledge of the disease.

300 ESTABLISHING THE PREVALENCE OF OSTEOPOROTIC FRACTURES IN IRELAND

Background

Fragility/low-trauma fractures are a major burden on health care, yet many could be prevented through Fracture Liaison Services (FLS). An Irish national FLS database (FLSDB) has recently been established and a reliable estimate of fracture numbers per locality is needed to measure FLS efficiency. Currently the Irish FLSDB uses the UK estimate of 1:4 hip vs. non-hip fracture numbers. We wanted to explore its accuracy in an Irish population.

Methods

We looked at all plain x-ray reports from six individual weeks across two years in our hospital. We selected those aged >50yrs with a reported new fracture. We determined the ratio of hip:non-hip fractures and of those admitted vs. discharged. We cross checked these against admitted fracture numbers from NQAIS (National Quality Assurance Information System) for the same 6 weeks. We then looked at all admissions Irish Emergency Departments during 2018-2019 with a new fracture aged >50yrs. We compared hip:non-hip fracture ratio of these vs. our local data.

Results

From 7,654 x-ray reports, 222 new fracture patients were identified. An additional 29 patients sustained fractures during this time period, either CT/MRI diagnoses or managed as fractures despite negative radiology report. NQAIS missed 21 admitted fractures (uncoded). The ratio admitted:discharged fractures in our audit was 2:3. Ratio of patients with hip:non-hip fractures was 1:9.5. Nationally there were 33,627 fracture patients aged >50y admitted to Irish hospitals in 2018-9, and of these, the hip:non-hip fracture ratio was 1:3. Adding estimated numbers of fracture patients not admitted (based on our local data) gives at least a 1:9 hip:non-hip ratio nationally.

Conclusion

Fracture numbers in Ireland are markedly underestimated if extrapolating from UK estimates. This has implications for service planning for Irish FLS, if rising fracture numbers are to be addressed.

Is it time to consider population screening for fracture risk in postmenopausal women? A position paper from the International Osteoporosis Foundation Epidemiology/Quality of Life Working Group

The IOF Epidemiology and Quality of Life Working Group has reviewed the potential role of population screening for high hip fracture risk against well-established criteria. The report concludes that such an approach should strongly be considered in many health care systems to reduce the burden of hip fractures.

INTRODUCTION

The burden of long-term osteoporosis management falls on primary care in most healthcare systems. However, a wide and stable treatment gap exists in many such settings; most of which appears to be secondary to a lack of awareness of fracture risk. Screening is a public health measure for the purpose of identifying individuals who are likely to benefit from further investigations and/or treatment to reduce the risk of a disease or its complications. The purpose of this report was to review the evidence for a potential screening programme to identify postmenopausal women at increased risk of hip fracture.

METHODS

The approach took well-established criteria for the development of a screening program, adapted by the UK National Screening Committee, and sought the opinion of 20 members of the International Osteoporosis Foundation's Working Group on Epidemiology and Quality of Life as to whether each criterion was met (yes, partial or no). For each criterion, the evidence base was then reviewed and summarized.

RESULTS AND CONCLUSION

The report concludes that evidence supports the proposal that screening for high fracture risk in primary care should strongly be considered for incorporation into many health care systems to reduce the burden of fractures, particularly hip fractures. The key remaining hurdles to overcome are engagement with primary care healthcare professionals, and the implementation of systems that facilitate and maintain the screening program.

Fracture liaison services in Ireland-how do we compare to international standards?

In this first na tional survey of public hospitals in The Republic of Ireland, we found fracture liaison services (FLS) to be heterogeneous, limited in many cases and poorly supported. A national strategy is urgently needed to support the implementation and operation of an FLS, and thus help reduce the burden of fragility fractures for patients and the healthcare system.

INTRODUCTION

Fragility/low-trauma fractures are a global concern, whose incidence is rising as the population ages. Many are preventable, and people with a prior fragility fracture are at particularly high risk of further fractures. This patient group is the target of the International Osteoporosis Foundation (IOF) Capture the Fracture campaign, advocating global adoption of fracture liaison services (FLS), with the aim of preventing secondary fragility fractures. We wished to determine the current availability and standards of an FLS in Ireland, ahead of the launch of a National FLS database.

METHODS

We devised a questionnaire encompassing the thirteen IOF standards for an FLS and asked all 16 public hospitals with an orthopaedic trauma unit in Ireland, to complete for the calendar year 2019 in patients aged ≥ 50 years.

RESULTS

All sites returned the questionnaire, i.e. 100% response rate. Nine hospitals stated that they have an FLS, additionally one non-trauma hospital running a FLS responded, and were included. These 10 FLS had identified and managed 3444 non-hip fractures in the year 2019. This figure represents 19% of the expected non-hip fragility fracture numbers occurring annually in Ireland. Implementation of the IOF standards was very variable. All sites reported being inadequately resourced to provide a high-quality service necessary to be effective.

CONCLUSION

The existence and functioning of FLS in Ireland are heterogeneous and suboptimal. A national policy to support the implementation of this programme in line with international standards of patient care is urgently needed.

1438 The Past, Present and Future Management of Complex Chyle Fistulae

Background

Chyle leak/fistula is a rare complication of oesophageal surgery, usually consequent on an unintended breach of the thoracic duct, its tributaries, or the cisterna chyli. For high volume persistent leaks further surgery has been the traditional approach, however two cases have resulted in a new management approach at this Centre.

Case Series

The first patient, a 49-year-old, developed high volume drain output post three stage oesophagectomy. His jejunostomy feeding was discontinued, total parenteral nutrition and a somatostatin analogue, were commenced. Despite these measures, the drain output remained >1.5litres per day and an exploratory thoracotomy was performed. The second patient, an 81-year-old underwent a transhiatal-oesophagectomy. On postoperative day 10 he developed acute onset shortness of breath, CXR demonstrated a large left sided pleural effusion. CT thorax demonstrated multiloculated complex pleural effusions. US guided pig tail drain was placed in the largest targetable effusion. The fluid was chylous in appearance. In both cases, an interventional radiological approach, not previously performed at this centre, provided definitive management. Lymphangiography was performed via injection of 1mL of Lipoidol® every 5 minutes into the inguinal lymph nodes to identify the cisterna chyli. A guidewire was advanced via the cisterna chyli with coils and glue used to embolize the leaking tracts.

Discussion

The lessons from this experience provide an algorithm for the management of chyle leaks, that will change practice at this centre. Embolization or disruption of thoracic duct and cisterna chyli leaks will be first line therapy for complex chyle leaks, with surgery reserved for where this fails.

POS1162 PREDICTORS OF HOSPITALISATION IN PATIENTS WITH RHEUMATIC DISEASE AND COVID-19 IN IRELAND: DATA FROM THE COVID-19 GLOBAL RHEUMATOLOGY ALLIANCE PHYSICIAN-REPORTED REGISTRY

Background:

There is limited data regarding the risk of hospitalisation in patients with rheumatic disease and COVID-19 in Ireland.

Objectives:

We used the COVID-19 Global Rheumatology Alliance (GRA) registry data to study outcomes and their predictors.

Methods:

We examined data on patients and their disease-related characteristics entered into the COVID-19 GRA provider registry from Ireland (24th March 2020 to 31st August 2020). Multivariable logistic regression was used to assess the association of demographic and clinical characteristics with hospitalisation.

Results:

Of 105 patients, 47 (45.6%) were hospitalised and 10 (9.5%) died. Multivariable logistic regression analysis showed age (OR=1.06, 95%CI 1.01 to 1.10), number of comorbidities (OR=1.93, 95%CI 1.11 to 3.35), and glucocorticoid use (OR=15.01, 95%CI 1.77 to 127.16) were significantly associated with hospitalisation. A diagnosis of inflammatory arthritis was associated with a lower odds of hospitalisation (OR=0.09, 95%CI 0.02 to 0.32).

All significant variable modelMost parsimonious modelUnadjusted OR (95% CI)Adjusted OR (95%CI)*Adjusted p-value*Adjusted OR (95%CI)&Adjusted p-value&Female0.45 (0.20-1.02)0.33 (0.05-2.23)0.34 (0.09-1.36)0.128Age (years)1.08 (1.05-1.11)1.04 (0.97-1.10)0.2241.06 (1.01-1.10)0.010Inflammatory arthritis0.11 (0.05-0.28)0.14 (0.02-0.95)0.0440.09 (0.02-0.32)<0.001Connective Tissue Disease and Other1.56 (0.62 - 3.92)No comorbidities0.11 (0.04-0.30)0.76 (0.09-6.58)0.802Most common comorbiditiesCOPD / asthma4.77 (1.23-18.54)3.09 (0.16-60.07)0.456CVD3.40 (1.31-8.85)0.11 (0.01-1.88)0.129Hypertension3.71 (1.52-9.08)0.56 (0.04-7.94)0.668Obesity0.58 (0.10-3.30)Number of comorbidities (Median, IQR)3.01 (1.92-4.72)2.99 (0.59-15.02)0.1841.93 (1.11-3.35)0.020Never Smokerref.0.889Ever Smoker3.17 (1.18-8.89)1.19 (0.10-13.68)Medication prior to COVID-19 diagnosisGlucocorticoids9.26 (1.95-43.89)18.14 (1.13-290.81)0.04115.01 (1.77-127.16)0.013csDMARD monotherapy0.42 (0.17-1.00)b/tsDMARD (monotherapy or in combination with csDMARD)0.24 (0.10-0.58)1.36 (0.19-9.72)0.557

Conclusion:

Increasing age, comorbidity burden, and glucocorticoid use were associated with hospitalisation, while a diagnosis of inflammatory arthritis was associated with lower odds of hospitalization.

Disclosure of Interests:

Richard Conway Speakers bureau: Janssen, Roche, Sanofi, Abbvie, Elena Nikiphorou Speakers bureau: AbbVie, Eli-Lilly, Gilead, Celltrion, Pfizer, Sanofi, Christiana Demetriou: None declared, Candice Low: None declared, Kelly Leamy: None declared, John Ryan: None declared, Ronan Kavanagh: None declared, Alexander Fraser: None declared, John Carey: None declared, Paul O’Connell: None declared, Rachael Flood: None declared, Ronan Mullan: None declared, David Kane: None declared, Philip Robinson Speakers bureau: UCB, Roche, Pfizer, Gilead, Janssen, Novartis, Eli Lilly, Abbvie, Grant/research support from: Abbvie, UCB, Novartis, Janssen, Pfizer, Jean Liew Grant/research support from: Pfizer, Rebecca Grainger Speakers bureau: Pfizer, Cornerstones, Janssen, Novartis, Abbvie, Geraldine McCarthy: None declared.

Antigenic response to CT-P13 and infliximab originator in inflammatory bowel disease patients shows similar epitope recognition

AIM

To test the cross-immunogenicity of anti-CT-P13 IBD patients' sera to CT-P13/infliximab originator and the comparative antigenicity evoked by CT-P13/infliximab originator sera.

METHODS

Sera of patients with IBD with measurable anti-CT-P13 antibodies were tested for their cross-reactivity to 5 batches of infliximab originator and CT-P13. Anti-drug antibody positive sera from treated patients were used to compare antigenic epitopes.

RESULTS

All 42 anti-CT-P13 and 37 anti-infliximab originator IBD sera were cross-reactive with infliximab originator and CT-P13 respectively. Concentration of anti-drug antibodies against infliximab originator or CT-P13 were strongly correlated both for IgG1 and IgG4 (P < 0.001). Anti-CT-P13 sera of patients with IBD (n = 32) exerted similar functional inhibition on CT-P13 or infliximab originator TNF binding capacity and showed reduced binding to CT-P13 in the presence of five different batches of CT-P13 and infliximab originator. Anti-CT-P13 and anti-infliximab originator IBD sera selectively enriched phage-peptides from the VH (CDR1 and CDR3) and VL domains (CDR2 and CDR3) of infliximab. Sera reactivity detected major infliximab epitopes in these regions of infliximab in 60%-79% of patients, and no significant differences were identified between CT-P13 and infliximab originator immunogenic sera. Minor epitopes were localised in framework regions of infliximab with reduced antibody reactivity shown, in 30%-50% of patients. Monoclonal antibodies derived from naïve individuals and ADA-positive IBD patients treated with CT-P13 provided comparable epitope specificity to five different batches of CT-P13 and infliximab originator.

CONCLUSIONS

These results strongly support a similar antigenic profile for infliximab originator and CT-P13, and point toward a safe switching between the two drugs in anti-drug antibody negative patients.

Combined rTMS and virtual reality brain-computer interface training for motor recovery after stroke

OBJECTIVE

Combining repetitive transcranial magnetic stimulation (rTMS) with brain-computer interface (BCI) training can address motor impairment after stroke by down-regulating exaggerated inhibition from the contralesional hemisphere and encouraging ipsilesional activation. The objective was to evaluate the efficacy of combined rTMS  +  BCI, compared to sham rTMS  +  BCI, on motor recovery after stroke in subjects with lasting motor paresis.

APPROACH

Three stroke subjects approximately one year post-stroke participated in three weeks of combined rTMS (real or sham) and BCI, followed by three weeks of BCI alone. Behavioral and electrophysiological differences were evaluated at baseline, after three weeks, and after six weeks of treatment.

MAIN RESULTS

Motor improvements were observed in both real rTMS  +  BCI and sham groups, but only the former showed significant alterations in inter-hemispheric inhibition in the desired direction and increased relative ipsilesional cortical activation from fMRI. In addition, significant improvements in BCI performance over time and adequate control of the virtual reality BCI paradigm were observed only in the former group.

SIGNIFICANCE

When combined, the results highlight the feasibility and efficacy of combined rTMS  +  BCI for motor recovery, demonstrated by increased ipsilesional motor activity and improvements in behavioral function for the real rTMS  +  BCI condition in particular. Our findings also demonstrate the utility of BCI training alone, as shown by behavioral improvements for the sham rTMS  +  BCI condition. This study is the first to evaluate combined rTMS and BCI training for motor rehabilitation and provides a foundation for continued work to evaluate the potential of both rTMS and virtual reality BCI training for motor recovery after stroke.

Traumatic pulmonary pseudocyst: An underreported entity

BACKGROUND

Traumatic pulmonary pseudocysts (TPP) are underreported cavitary lesions of the pulmonary parenchyma that can develop following blunt chest trauma. Although the occurrence of traumatic pulmonary pseudocyst is rare, this condition should be considered in the differential diagnosis of any cavitary lesion. Awareness of this injury and its clinical significance is important for successful management in order to avoid medical errors in the course of treatment.

METHODS

A literature search was conducted through Medline using the key phrases "traumatic pulmonary pseudocyst" and "traumatic pneumatocele." Relevant articles, especially those with focus on diagnosis and management of traumatic pneumatocele in adults, were selected. Due to the scarcity of literature and lack of Level I evidence on this subject, studies published in any year were considered.

RESULTS

A search of "traumatic pulmonary pseudocyst" and "traumatic pneumatocele" yielded 114 studies. Most of these were excluded based on inclusion and exclusion criteria. Thirty-five articles were reviewed. The majority of these were individual case studies; only eight articles were considered large case studies (greater than eight patients).

CONCLUSION

Traumatic pulmonary pseudocysts are lesions that occur secondary to blunt chest trauma. Diagnosis is based on a history of trauma and appearance of a cystic lesion on CT. Accurate diagnosis of traumatic pulmonary pseudocyst is imperative to achieve successful outcomes. Failure to do so may lead to unnecessary procedures and complications.

ANCA-associated vasculitis: a comparison of cases presenting to nephrology and rheumatology services

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA) -associated vasculitis (AAV) is a disease characterized by inflammation of small vessels and detectable ANCA in the circulation. Patients may develop a broad spectrum of clinical features ranging from indolent sino-nasal disease and rashes to fulminant renal failure or acute life-threatening pulmonary haemorrhage. Consequently, patients with AAV present to a variety of specialties including nephrology and rheumatology, whose training and approaches to management of such patients may differ. There is little literature comparing patients presenting to different specialties and their outcomes.

METHODS

We compared two cohorts of patients with ANCA-positive AAV presenting to either the rheumatology or nephrology department at Galway University Hospitals from June 2002 to July 2011. A standardized data collection form was used to collect information regarding baseline demographics, manifestations of AAV, initial management, relapses and complications.

RESULTS

Forty-five patients were included in this study (15 rheumatology/30 nephrology). The nephrology cohort was older, had a higher C-reactive protein, Birmingham Vascular Activity Score and ANCA titer at presentation compared to the rheumatology group. Induction treatment varied between the cohorts with rheumatology patients most commonly receiving a combination of oral corticosteroids (73%) and methotrexate (60%) and nephrology patients receiving a combination of intravenous corticosteroids (93%) and cyclophosphamide (90%). Fifty-three percent of the rheumatology patients who completed induction therapy relapsed compared to 30% of the nephrology patients.

CONCLUSION

This study presents two different cohorts of patients with the same disease that were managed by two different disciplines. It highlights the heterogeneity of AAV and the importance of interdisciplinary communication and cooperation when managing these patients.

Post-combustion carbon dioxide capture cost reduction to 2030 and beyond

Post-combustion CO₂ capture (PCC) can be achieved using a variety of technologies. Importantly it is applicable to a wide range of processes and may also be retrofitted in certain cases. This paper covers the use of PCC for low carbon power generation from new natural gas combined cycle (NGCC) plants that are expected to be built in the UK in the 2020s and 2030s and that will run into the 2050s. Costs appear potentially comparable with other low carbon and controllable generation sources such as nuclear or renewables plus storage, especially with the lower gas prices that can be expected in a carbon-constrained world. Non-fuel cost reduction is still, however, desirable and, since CO₂ capture is a new application, significant potential is likely to exist. For the NGCC+PCC examples shown in this paper, moving from ‘first of a kind’ (FOAK) to ‘nth of a kind’ (NOAK) gives significant improvements through both reduced financing costs and capital cost reductions. To achieve this the main emphasis needs to be on ‘commercial readiness’, rather than on system-level ‘technical readiness’, and on improvements through innovation activities, supported by underpinning research, that develop novel sub-processes; this will also maintain NOAK status for cost-effective financing. Feasible reductions in the energy penalty for PCC capture have much less impact, reflecting the inherently high levels of efficiency for modern NGCC+PCC plants.

Expanding access to rheumatology care: the rheumatology general practice toolbox

Management guidelines for many rheumatic diseases are published in specialty rheumatology literature but rarely in general medical journals. Musculoskeletal disorders comprise 14% of all consultations in primary care. Formal post-graduate training in rheumatology is limited or absent for many primary care practitioners. Primary care practitioners can be trained to effectively treat complex diseases and have expressed a preference for interactive educational courses. The Rheumatology General Practice (GP) Toolbox is an intensive one day course designed to offer up to date information to primary care practitioners on the latest diagnostic and treatment guidelines for seven common rheumatic diseases. The course structure involves a short lecture on each topic and workshops on arthrocentesis, joint injection and DXA interpretation. Participants evaluated their knowledge and educational experience before, during and after the course. Thirty-two primary care practitioners attended, who had a median of 13 (IQR 6.5, 20) years experience in their specialty. The median number of educational symposia attended in the previous 5 years was 10 (IQR-5, 22.5), with a median of 0 (IQR 0, 1) in rheumatology. All respondents agreed that the course format was appropriate. Numerical improvements were demonstrated in participant's confidence in diagnosing and managing all seven common rheumatologic conditions, with statistically significant improvements (p < 0.05) in 11 of the 14 aspects assessed. The Rheumatology Toolbox is an effective educational method for disseminating current knowledge in rheumatology to primary care physicians and improved participant's self-assessed competence in diagnosis and management of common rheumatic diseases.

Multiobjective optimization framework for landmark measurement error correction in three-dimensional cephalometric tomography

The purpose of this study is to minimize errors that occur when using a four vs six landmark superimpositioning method in the cranial base to define the co-ordinate system. Cone beam CT volumetric data from ten patients were used for this study. Co-ordinate system transformations were performed. A co-ordinate system was constructed using two planes defined by four anatomical landmarks located by an orthodontist. A second co-ordinate system was constructed using four anatomical landmarks that are corrected using a numerical optimization algorithm for any landmark location operator error using information from six landmarks. The optimization algorithm minimizes the relative distance and angle between the known fixed points in the two images to find the correction. Measurement errors and co-ordinates in all axes were obtained for each co-ordinate system. Significant improvement is observed after using the landmark correction algorithm to position the final co-ordinate system. The errors found in a previous study are significantly reduced. Errors found were between 1 mm and 2 mm. When analysing real patient data, it was found that the 6-point correction algorithm reduced errors between images and increased intrapoint reliability. A novel method of optimizing the overlay of three-dimensional images using a 6-point correction algorithm was introduced and examined. This method demonstrated greater reliability and reproducibility than the previous 4-point correction algorithm.

A case of occupational gout

Gout can occur in any joint but most commonly afflicts the first metatarsophalangeal joint. Many theories have been suggested as explanations for this preferential joint involvement. We describe a case of gout occurring in the fingers of a man with occupational cold exposure, a case of "occupational" gout, and support for the involvement of temperature in acute attacks of gout.

Vitamin D supplementation versus combined calcium and vitamin D in older female patients - an observational study

BACKGROUND

In most developed countries overt vitamin D deficiency, characterized by rickets or osteomalacia, is now uncommon. However, subclinical vitamin D insufficiency is extremely common and may contribute to the development of skeletal and non-skeletal problems. Standard practice involves supplementation with a combination of vitamin D and calcium although the benefit of adding calcium to vitamin D supplements has not been fully established and may reduce adherence due to its bulky and chalky consistency.

PURPOSE OF STUDY

To compare the effects of vitamin D alone versus vitamin D/calcium supplements on vitamin D levels, bone profile and parathyroid hormone level.

POPULATION

Older (> 65 years) female patients living in the community and long term care institutions.

INTERVENTIONS

Either 800 iu of vitamin D3 or a composite supplement of 800 iu vitamin D3 and 1000 mg calcium were given to patients in an open-labelled observational study. Serum 25-hydroxy-vitamin D, parathyroid hormone, calcium, phosphate and alkaline phosphatase levels were assessed at baseline and after 3 months of treatment.

RESULTS

Serum 25-hydroxy-vitamin D levels rose from baseline levels of 25 ± 16 to 79 ± 16 in those treated with vitamin D alone and from 35 ± 24 nmol/L to 70 ± 24 nmol/L in those treated with vitamin D and calcium. Serum PTH levels fell by similar amounts in both groups. In both community dwellers and institutionalised patients, those treated with vitamin D alone were at least as likely to achieve normalisation of serum vitamin D levels as those on combined calcium/vitamin D treatment.

CONCLUSION

Vitamin D alone appears as effective as combined calcium/vitamin D treatment in restoring serum vitamin D levels in older community dwelling and institutionalised patients. A prospective randomised trial would help confirm these findings.

Pasteurization of chicken litter with steam and quicklime to reduce Salmonella Typhimurium

The nursery industry pasteurizes soil with steam and quicklime to reduce plant pathogens. The mechanism of action for quicklime is the resulting exothermic reaction that occurs when the chemical interacts with water and its ability to increase pH levels. These treatments may also reduce pathogens in a commercial poultry house. In this study, a steam sterilization cart simulated conditions used by the nursery industry to treat litter inoculated with Salmonella enterica serovar Typhimurium. A homogenized sample of litter was exposed to steam for 0, 5, 30, or 120 min. Quicklime was used at concentrations of 0 (control), 2.5, 5.0, or 10.0%. All steam treatments, with or without quicklime, significantly reduced Salmonella Typhimurium colonization by at least 3 orders of magnitude. Significant reductions were also observed in the treatments with quicklime alone. Both the steam and the quicklime treatments often reduced colonization to undetectable levels, even when samples were enriched. Therefore, we demonstrated 2 novel techniques for reducing Salmonella Typhimurium in poultry litter. Soil pasteurization potentially offers an environmentally sound means of reducing the pathogens present in used poultry litter.

Sensitivity analysis for plane orientation in three-dimensional cephalometric analysis based on superimposition of serial cone beam computed tomography images

OBJECTIVES

The purpose of this study was to evaluate the potential errors associated with superimposition of serial cone beam CT (CBCT) images utilizing reference planes based on cranial base landmarks using a sensitivity analysis.

METHODS

CBCT images from 62 patients participating in a maxillary expansion clinical trial were analysed. The left and right auditory external meatus (AEM), dorsum foramen magnum (DFM) and the midpoint between the left and right foramen spinosum (ELSA) were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Intraclass correlation coefficients for all four landmarks were obtained. Transformation of the reference system was carried out using the four landmarks and mathematical comparison of values.

RESULTS

Excellent intrareliability values for each dimension were obtained for each landmark. Evaluation of the method to transform the co-ordinate system was first done by comparing interlandmark distances before and after transformations, giving errors in lengths in the order of 10-14% (software rounding error). A sensitivity evaluation was performed by adding 0.25 mm, 0.5 mm and 1 mm error in one axis of the ELSA. A positioning error of 0.25 mm in the ELSA can produce up to 1.0 mm error in other cranial base landmark co-ordinates. These errors could be magnified to distant landmarks where in some cases menton and infraorbital landmarks were displaced 4-6 mm.

CONCLUSIONS

Minor variations in location of the ELSA, both the AEM and the DFM landmarks produce large and potentially clinically significant uncertainty in co-ordinate system alignment.

Effect of object location on the density measurement and Hounsfield conversion in a NewTom 3G cone beam computed tomography unit

OBJECTIVES

The purpose of this study was to determine the effect of an object's location in a cone beam CT imaging chamber (CBCT-NewTom 3G) on its apparent density and to develop a linear conversion coefficient for Hounsfield units (HU) to material density (g cm(-3)) for the NewTom 3G Scanner.

METHODS

Three cylindrical models of materials with different densities were constructed and scanned at five different locations in a NewTom 3G Volume Scanner. The average HU value for each model at each location was obtained using two different types of software. Next, five cylinders of different known densities were scanned at the exact centre of a NewTom 3G Scanner. The collected data were analysed using the same two types of software to determine a standard linear relationship between density and HU for each type of software.

RESULTS

There is no statistical significance of location of an object within the CBCT scanner on determination of its density. A linear relationship between the density of an object and the HU of a scan was rho = 0.001(HU)+1.19 with an R2 value of 0.893 (where density, rho, is measured in g cm(-3)). This equation is to be used on a range between 1.42 g cm(-3) and 0.4456 g cm(-3).

CONCLUSIONS

A linear relationship can be used to determine the density of materials (in the density range of bone) from the HU values of a CBCT scan. This relationship is not affected by the object's location within the scanner itself.

Probe-guided localization of cancer deposits using [18F]fluorodeoxyglucose

In recent years, several probes have been developed to allow for the intraoperative detection of tumour tissue using [18F]fluorodeoxyglucose (FDG). Detector designs include high-energy gamma and beta probes, as well as combination devices with background rejection capabilities. Some laboratory prototypes and commercialized systems have demonstrated reasonable sensitivities for 511 keV photons and /or b particles emitted from 18F for in vivo use. This review focuses on the ability of these devices to detect tumour deposits in the low-contrast environment of the operating room . Important technical and biological factors that influence tumour-to-background contrast are discussed and potential future applications and developments are highlighted. In addition, we evaluate the limited data on absorbed doses resulting from [18F] FDG administration immediately prior to surgery that indicate acceptable levels of radiation exposure to operating room personnel.

MC1R variants correlate with thinhorn sheep colour cline but not individual colour

The melanocortin 1 receptor (MC1R) gene has provided a window on the evolution of colour polymorphisms. Recent studies have demonstrated associations between MC1R and melanism in a number of wildlife species. Thinhorn sheep ( Ovis dalli Nelson, 1884) are a possible species to test for association between MC1R polymorphisms and melanism. Across their range the pelage colour of thinhorn sheep intergrades between all white phenotypes to very dark phenotypes. Most thinhorn sheep are white; however, there is a 1200 km cline from light to dark sheep that occurs over three genetically distinct polymorphic populations. We sequenced the entire MC1R gene from 40 individuals across the range of thinhorn sheep. We found a single nucleotide polymorphism in MC1R at base pair position 921 that coincided with the geographic cline. However, at the individual level we found no relationship between individual melanism and genotype.

Horn growth rate and longevity: implications for natural and artificial selection in thinhorn sheep (Ovis dalli)

We used horn measurements from natural and hunted mortalities of male thinhorn sheep Ovis dalli from Yukon Territory, Canada, to examine the relationship between rapid growth early in life and longevity. We found that rapid growth was associated with reduced longevity for sheep aged 5 years and older for both the hunted and natural mortality data sets. The negative relationship between growth rate and longevity in hunted sheep can at least partially be explained by morphologically biased hunting regulations. The same trend was evident from natural mortalities from populations that were not hunted or underwent very limited hunting, suggesting a naturally imposed mortality cost directly or indirectly associated with rapid growth. Age and growth rate were both positively associated with horn size at death for both data sets, however of the two growth rate appeared to be a better predictor. Large horn size can be achieved both by individuals that grow horns rapidly and by those that have greater longevity, and the trade-off between growth rate and longevity could limit horn size evolution in this species. The similarity in the relationship between growth rate and longevity for hunted and natural mortalities suggests that horn growth rate should not respond to artificial selection. Our study highlights the need for the existence and study of protected populations to properly assess the impacts of selective harvesting.

Density conversion factor determined using a cone-beam computed tomography unit NewTom QR-DVT 9000

OBJECTIVE

The purpose of this study was to determine a conversion coefficient for Hounsfield Units (HU) to material density (g cm(-3)) obtained from cone-beam computed tomography (CBCT-NewTom QR-DVT 9000) data.

METHODS

Six cylindrical models of materials with different densities were made and scanned using the NewTom QR-DVT 9000 Volume Scanner. The raw data were converted into DICOM format and analysed using Merge eFilm and AMIRA to determine the HU of different areas of the models.

RESULTS

There was no significant difference (P = 0.846) between the HU given by each piece of software. A linear regression was performed using the density, rho (g cm(-3)), as the dependent variable in terms of the HU (H). The regression equation obtained was rho = 0.002H-0.381 with an R2 value of 0.986. The standard error of the estimation is 27.104 HU in the case of the Hounsfield Units and 0.064 g cm(-3) in the case of density.

CONCLUSION

CBCT provides an effective option for determination of material density expressed as Hounsfield Units.

Evidence for cryptic glacial refugia from North American mountain sheep mitochondrial DNA

The separation of populations by ice sheets into large refugia can account for much of the genetic diversity found in present day populations. The evolutionary implications of small glacial refugia have not been as thoroughly explored. To examine refugial origins of North American mountain sheep Ovis spp., we analyzed a 604 bp portion of the mitochondrial DNA (mtDNA) control region from 223 O. dalli and O. canadensis. Major refugia were identified in eastern Beringia and southern North America, and we found evidence for two smaller refugia situated between the Laurentide and Cordilleran glaciers. Our results are the first to demonstrate support for survival of any organism in the latter two refugia. These refugia also appear to have conserved a genetic signal that confirms past hybridization of O. dalli and O. canadensis.

Detecting the signature of selection on immune genes in highly structured populations of wild sheep (Ovis dalli)

The confounding effects of population structure complicate efforts to identify regions of the genome under the influence of selection in natural populations. Here we test for evidence of selection in three genes involved in vertebrate immune function - the major histocompatibility complex (MHC), interferon gamma (IFNG) and natural resistance associated macrophage polymorphism (NRAMP) - in highly structured populations of wild thinhorn sheep (Ovis dalli). We examined patterns of variation at microsatellite loci linked to these gene regions and at the DNA sequence level. Simple Watterson's tests indicated balancing selection at all three gene regions. However, evidence for selection was confounded by population structure, as the Watterson's test statistics from linked markers were not outside of the range of values from unlinked and presumably neutral microsatellites. The translated coding sequences of thinhorn IFNG and NRAMP are fixed and identical to those of domestic sheep (Ovis aries). In contrast, the thinhorn MHC DRB locus shows significant evidence of overdominance through both an excess of nonsynonymous substitution and trans-species polymorphism. The failure to detect balancing selection at microsatellite loci linked to the MHC is likely the result of recombination between the markers and expressed gene regions.

Gender- and age-class-specific reactions to human disturbance in a sexually dimorphic ungulate

According to optimality theory, an individual's characteristics should play a major part in determining antipredator strategies. We studied behavioural reactions to human presence of gender and age classes of 35 thinhorn sheep (Ovis dalli Nelson, 1884) in late winter 2001 in Faro, Yukon Territory, Canada. The behaviour of undisturbed sheep was observed from distances of 400–1200 m and compared with the behaviour recorded when one or two people were in close proximity to the sheep. Ewes decreased bedding and increased foraging when humans were present, but there were no changes in these behaviours in rams. Disturbance caused an increase in vigilance and a trend was found for adults to react more strongly to disturbance than juveniles. We demonstrate the importance for disturbance research of gaining detailed information about all different kinds of population members and using applicable statistical tests in the data analyses.

Abnormal motor behavior and vestibular dysfunction in the stargazer mouse mutant

In stargazer mutant mice, a mutation in the gene encoding stargazin results in absence epilepsy, cerebellar ataxia, and a characteristic abnormal motor syndrome. The main goal of the current studies was to characterize the nature and source of the abnormal motor behavior. Because the stargazer motor syndrome resembles that of other rodents with vestibular dysfunction, the motor abnormalities were compared with those of normal mice treated with toxins known to damage the vestibular system. Quantitative open field assessments revealed that the stargazer mice display a motor syndrome very similar to that exhibited by mice with toxin-induced vestibulopathy. However, stargazer mice also displayed several additional behaviors, such as ataxic gait and sustained extensor movements of the neck. In addition, stargazer mice performed worse than mice with toxin-induced vestibulopathy in most standard tests of motor function. Motor function was also impaired on each of four behavioral tests sensitive to vestibular function. Because of the close associations between the vestibular and auditory systems, tests of auditory function were also employed. The stargazer mutants exhibited relatively normal auditory brainstem evoked responses but no apparent acoustic startle reflex. Histological examination of vestibular sensory epithelium at the light and electron microscopic levels confirmed the existence of abnormalities in the stargazer mutants. These results imply a previously unrecognized role for stargazin in the normal functions of the vestibular system and indicate that some, but not all, of the abnormal motor syndrome of stargazer mice can be attributed to vestibular dysfunction.

Population genetic structure of North American thinhorn sheep (Ovis dalli)

The thinhorn sheep (Ovis dalli ssp.) provides a rare example of a North American large mammal that occupies most of its native range and maintains close to ancestral population size. There are currently two recognized subspecies, Dall's sheep (O. d. dalli) and Stone's sheep (O. d. stonei), the validity of which remains uncertain. We investigated the spatial genetic structure of thinhorn sheep populations representing both subspecies by genotyping individuals (n = 919) from across the species range at 12 variable microsatellite loci. We found high levels of genetic diversity within (HE = 0.722) and significant genetic structure among the 24 sampled areas (FST = 0.160). Genetic distance measures and Bayesian clustering analyses revealed the presence of at least eight subpopulations that are delineated by mountain range topology. A strong overall pattern of isolation-by-distance is evident across the sampling range (r = 0.75, P < 0.001) suggesting limited dispersal and extensive philopatry. Partial Mantel tests of this relationship showed mountain range distinctions represent significant barriers to gene flow (P = 0.0001), supporting the Bayesian analyses. Genetic structure was more strongly pronounced in southern Yukon and Alaska than elsewhere. We also show evidence for genetic differences between the two currently recognized thinhorn subspecies.