AB0980 Hand Osteoarthritis: investigating Pain Effects in a randomised placebo-controlled feasibility study of estrogen-containing therapy (HOPE-e): report on the primary feasibility outcomes

Background

There is an unmet need for new treatments for hand osteoarthritis (OA). Symptomatic hand OA is more common in women and its incidence increases round the age of menopause. Pre-clinical, epidemiological and post hoc studies in Hormone Replacement Therapy (HRT) trials implicate estrogen deficiency as of likely importance in OA aetiopathogenesis. No clinical trials of HRT have been carried out in hand OA to date. The licensed HRT Duavive (conjugated estrogens + SERM bazedoxifene) was selected on its potential for efficacy and tolerability.

Objectives

We set out to determine the feasibility and acceptability of this form of HRT in post-menopausal women with hand OA, to generate proof of concept data and refine methods for a full study.

Methods

ISRCTN12196200. Females aged 40-65 yrs and 1-10yrs after final menstrual period with hand OA fulfilling ACR criteria and 2+ painful hand joints were recruited. Eligibility incorporated best practice for HRT prescription but did not require menopausal symptoms. Recruitment was at 3 sites in primary/secondary care, including directly from the community. Design was parallel group, double-blind 1:1 randomisation of Duavive or placebo, orally once daily for 24 weeks, then weaning for 4 weeks before stopping. Routes and rates of recruitment and the acceptability of randomisation, medication (compliance, retention), and proposed outcomes were measured, and the likelihood of unblinding. Measures related to hand pain and function, menopause symptoms and joint appearance. Patient and Public Involvement actively informed study rationale, design and materials. An end of study questionnaire and 2 participant focus groups provided further acceptability data.

Results

Recruitment was for 12/possible 18 months, interrupted due to COVID-19. Some study procedures were modified to allow reopening whilst collecting all primary outcomes. 434 enquiries/referrals were received, leading to 96 telephone pre-screens, of which 33 gave written informed consent and attended face to face screening. 28/33 screened (85%) were eligible and randomised. The highest number of randomisations was from study web presence (n=7) followed by SMS text from GP surgeries (n=5). Of 401 not proceeding, 250 (62%) were ineligible, most commonly due to contraindicated medication, followed by medical contraindication, whilst 55 (14%) decided not to take part, for reasons including not wanting to take a hormone-based drug or difficulty attending study visits. Retention and compliance were excellent. All 28 participants completed all study follow ups, with only 3 withdrawals from treatment due to AEs, 2 of these at week 24 and all in the placebo arm. There were no serious AEs. High levels of completeness of all study outcome measures were achieved. Bang’s blinding index suggested that participants/investigators were well blinded. There were overall high/good levels of satisfaction with taking part in the study. 26/28 (92%) would recommend taking part to others with hand OA (irrespective of study arm). Many found the flexibility offered by a combination of remote and face to face visits (due to the pandemic) attractive. Additional insights from focus groups were to include hand stiffness as well as pain measures but to reduce the overall number of questions.

Conclusion

Despite COVID-19 and a reduced recruitment period, this study recruited sufficient numbers to assess feasibility outcomes. Randomisation of eligible people and retention rates were high. A mixture of remote and face to face visits due to COVID-19 probably improved recruitment and retention and was supported by participants, who were generally satisfied with the study design and medication. The study provided useful insight and improvements that would be incorporated into a future study. Overall, this feasibility study showed that with clear messaging on eligibility and a defined recruitment strategy, recruitment and retention to a study testing this treatment is possible.

Acknowledgements

This research was funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) Programme (Grant Reference Number PB-PG-0416-20023). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. The study team thank the sites and the participants who made this research possible.

Disclosure of Interests

Jennifer A.E. Williams: None declared, Mae Chester-Jones: None declared, Anne Francis: None declared, Ioana Marian: None declared, Megan Goff: None declared, Gretchen Brewer: None declared, Malvika Gulati: None declared, Lucy Eldridge: None declared, Patrick Julier: None declared, Catherine Minns Lowe: None declared, Vicki Barber: None declared, Victoria Glover: None declared, Charles Mackworth-Young: None declared, Tonia Vincent Consultant of: Pfizer, Grant/research support from: Grant support from Fidia, Biosplice, Novartis, Pfizer as part of their contribution to an international consortium., Sarah E Lamb: None declared, Katy Vincent: None declared, Susan J Dutton: None declared, Fiona E Watt Consultant of: Pfizer, Grant/research support from: Pfizer and from Astellas Pharma (> 3 years ago)

Acute effects of exercise on cerebrovascular response and cognitive performance in individuals with stable coronary heart disease

BACKGROUND

Individuals with coronary heart disease (CHD) exhibit cognitive deficits and cerebrovascular dysfunctions, and are at higher risk of developing dementia. Cognitive function in individuals with CHD has never been studied during acute aerobic exercise. Given the increasing popularity of training at high peak power output (PPO), its impact on cerebrovascular and cognitive functions in individuals with CHD should be further studied.

METHOD

Thirty-eight individuals with CHD and 16 healthy controls completed two exercise bouts at 30% and 70% of their individualized PPO on an ergocycle while performing a cognitive task including non-executive and executive conditions. Variations of oxy- deoxy-hemoglobin, and total hemoglobin concentrations were measured on left prefrontal cortex at both PPO using near-infrared spectroscopy.

RESULTS

Cognitive task performances were equivalent between groups at all intensity levels. Individuals with CHD exhibited larger variation of deoxyhemoglobin in the executive condition and larger variation in total hemoglobin concentration in all task conditions compared to healthy controls at 70% of PPO.

CONCLUSION

Exercising at high intensity seems to have a larger impact on cerebral blood volume in CHD patients compared to healthy age-matched controls. Higher exercise intensity has negative impacts on cerebral blood volume variations during a cognitive task in CHD patients and could potentially lead to other neurocognitive dysfunctions. Other studies are needed to determine if a cognitive task administered during an exercise test could help identify individuals with CHD at higher risk of developing cognitive decline.

Cognitive ageing is premature among a community sample of optimally treated people living with HIV

OBJECTIVES

Evidence of premature cognitive ageing amongst people living with HIV (PLHIV) remains controversial due to previous research limitations including underpowered studies, samples with suboptimal antiretroviral access, varying rate of virological control, high rate of AIDS, over-representation of non-community samples, and inclusion of inappropriate controls. The current study addresses these limitations, while also considering mental health and non-HIV comorbidity burden to determine whether PLHIV showed premature cognitive ageing compared with closely comparable HIV-negative controls.

METHODS

This study enrolled 254 PLHIV [92% on antiretroviral therapy; 84% with HIV RNA < 50 copies/mL; 15% with AIDS) and 72 HIV-negative gay and bisexual men [mean (SD) age = 49 (10.2) years] from a single primary care clinic in Sydney, Australia. Neurocognitive function was evaluated with the Cogstate Computerized Battery (CCB) at baseline and 6 months after. Linear mixed-effects (LME) models examined main and interaction effects of HIV status and chronological age on the CCB demographically uncorrected global neurocognitive z-score (GZS), adjusting for repeated testing, and then adjusting sequentially for HIV disease markers, mental health and comorbidities.

RESULTS

HIV status and age interacted with a lower GZS (β = -0.43, P < 0.05). Higher level of anxiety symptoms (β = -0.11, P < 0.01), historical AIDS (β = -0.12, P < 0.05) and historical HIV brain involvement (β = -0.12, P < 0.05) were associated with lower GZS.

CONCLUSIONS

We found a robust medium-sized premature ageing effect on cognition in a community sample with optimal HIV care. Our study supports routine screening of cognitive and mental health among PLHIV aged ≥ 50 years.

Molecular and structural imaging in surgically induced murine osteoarthritis

Preclinical imaging in osteoarthritis is a rapidly growing area with three principal objectives: to provide rapid, sensitive tools to monitor the course of experimental OA longitudinally; to describe the temporal relationship between tissue-specific pathologies over the course of disease; and to use molecular probes to measure disease activity in vivo. Research in this area can be broadly divided into those techniques that monitor structural changes in tissues (microCT, microMRI, ultrasound) and those that detect molecular disease activity (positron emission tomography (PET), optical and optoacoustic imaging). The former techniques have largely evolved from experience in human joint imaging and have been refined for small animal use. Some of the latter tools, such as optical imaging, have been developed in preclinical models and may have translational benefit in the future for patient stratification and for monitoring disease progression and response to treatment. In this narrative review we describe these methodologies and discuss the benefits to animal research, understanding OA pathogenesis, and in the development of human biomarkers.

FRI0406 CARTILAGE REPAIR ACTIVITY DURING JOINT-PRESERVING TREATMENT MAY BE ACCOMPANIED BY OSTEOPHYTE FORMATION

Background:

Knee joint distraction (KJD) is a joint-preserving treatment to postpone total knee arthroplasty (TKA) and has shown cartilage repair and clinical improvement in patients with severe knee osteoarthritis (OA), as has high tibial osteotomy (HTO). The observed cartilage repair activity could be related to an increase in transforming growth factor-β1 (TGFβ-1), which increases in the synovial fluid (SF) during KJD treatment.1However, animal and ex vivo human studies have shown that TGFβ-1 also induce formation of osteophytes, generally seen as an OA severity hallmark. Similarly, interleukin-6 (IL-6) was observed to increase in SF during KJD treatment and may also be associated with osteophytosis.

As such, we hypothesized that joint-preserving regenerative treatments demonstrating cartilage repair activity lead to general tissue (re)generation, including osteophytosis.

Objectives:

To analyze osteophytosis after KJD and compare this to HTO and natural progression in knee OA.

Methods:

63 KJD patients were included in several clinical trials, one of which was a randomized controlled trial comparing patients indicated for HTO, but treated with KJD (KJDHTO; n=23) vs. patients treated with HTO (n=46). All patients received standardized radiographs before and one and two years after treatment, used to measure osteophyte size. Only patients with measurements at baseline and two-year follow-up were included. As a control group for natural progression, untreated knee OA patients from Cohort Hip & Cohort Knee (CHECK; n=1002) were studied. Only patients who received a TKA during follow-up were included, using their last two measurements before treatment to reflect natural two-year progression (n=44).

A separate group of 20 patients treated with KJD in regular care underwent SF aspirations before and after treatment, and TGFβ-1 and IL-6 levels were measured by immunoassay (Mesoscale Discovery). Unstandardized radiographs were acquired before and one year after treatment, used to score osteophytes with the revised Altman score, resulting in a 0 (normal) to 12 (severe) whole-joint score. Only patients with radiographs and SF aspirations at both baseline and one-year follow-up were included.

Results:

After two years, both KJD (n=58) and HTO (n=38) patients showed a significant increase in osteophyte size (+6.2mm2 and +7.0mm2 resp.; both p<0.003; figure 1), with no significant differences between the treatments (p>0.38). Untreated CHECK patients who underwent TKA did not show significant two-year osteophyte changes before treatment (+2.1mm2; p=0.207; figure 1) and showed significant differences compared with KJD and HTO groups (both p<0.044). In the KJD SF aspiration group (n=17), the Altman osteophyte score was not different at one year compared to baseline (+0.2 points; p=0.653) and there was no association between baseline biomarker values and the baseline Altman osteophyte score, or between changes in these parameters (all p≥0.28). Trichotomization of patients in groups with a decrease, no change or increase in total Altman osteophyte score indicated that there was a statistically significant difference between the three groups in changes in TGFβ-1 (p=0.044; figure 2A), but not IL-6 (p=0.898; figure 2B).

Conclusion:

After KJD treatment, joint space widening and clinical improvement are accompanied by osteophytosis. Similar results were observed after treatment with HTO, suggesting effects occur in regenerative joint-preserving treatments in general. The increased osteophytosis may be a bystander effect of cartilage repair activity related to intra-articular factors like TGFβ-1 and questions whether osteophytosis should necessarily be considered a hallmark of OA worsening.

References:

[1]Watt et al, Osteoarthritis Cartilage 2020

Disclosure of Interests:

Mylène Jansen: None declared, Simon Mastbergen: None declared, Fiona Watt: None declared, Elske Willemse: None declared, Tonia Vincent Consultant of: Ad hoc consultancy GSK, Mundipharma, UCB, Sander Spruijt Consultant of: Consultancy to Zimmer Biomet Inc., Pieter Emans Shareholder of: Shareholder and cofounder start-up company Chondropeptix, Roel Custers: None declared, Ronald Van Heerwaarden: None declared, Floris Lafeber Shareholder of: Co-founder and shareholder of ArthroSave BV

Exploring functionalized titania for task specific application of efficient separation of trivalent f-block elements

Functionalized titania, obtained by grafting the dipicolinic acid functionality, was explored for task specific application of highly efficient separation of trivalent f-block elements.

Optimal positioning of optodes on the scalp for personalized functional near-infrared spectroscopy investigations

BACKGROUND

Application of functional Near InfraRed Spectroscopy (fNIRS) in neurology is still limited as a good optical coupling and optimized optode coverage of specific brain regions remains challenging, notably for prolonged monitoring.

METHODS

We propose to evaluate a new procedure allowing accurate investigation of specific brain regions. The procedure consists in: (i) A priori maximization of spatial sensitivity of fNIRS measurements targeting specific brain regions, while reducing the number of applied optodes in order to decrease installation time and improve subject comfort. (ii) Utilization of a 3D neuronavigation device and usage of collodion to glue optodes on the scalp, ensuring good optical contact for prolonged investigations. (iii) Local reconstruction of the hemodynamic activity along the cortical surface using inverse modelling.

RESULTS

Using realistic simulations, we demonstrated that maps derived from optimal montage acquisitions showed, after reconstruction, spatial resolution only slightly lower to that of ultra high density montages while significantly reducing the number of optodes. The optimal montages provided overall good quantitative accuracy especially at the peak of the spatially reconstructed map. We also evaluated real motor responses in two healthy subjects and obtained reproducible motor responses over different sessions.

COMPARISON WITH EXISTING METHODS

We are among the first to propose a mathematical optimization strategy, allowing high sensitivity measurements.

CONCLUSIONS

Our results support that using personalized optimal montages should allow to conduct accurate fNIRS studies in clinical settings and realistic lifestyle conditions.

Real-time diffraction computed tomography data reduction

Diffraction imaging is an X-ray imaging method which uses the crystallinity information (cell parameter, orientation) as a signal to create an image pixel by pixel: a pencil beam is raster-scanned onto a sample and the (powder) diffraction signal is recorded by a large area detector. With the flux provided by third-generation synchrotrons and the speed of hybrid pixel detectors, the acquisition speed of these experiments is now limited by the transfer rate to the local storage as the data reduction can hardly be performed in real time. This contribution presents the benchmarking of a typical data analysis pipeline for a diffraction imaging experiment like the ones performed at ESRF ID15a and proposes some disruptive techniques to decode CIF binary format images using the computational power of graphics cards to be able to perform data reduction in real time.

Distinctive cutaneous and systemic features associated with specific antimyositis antibodies in adults with dermatomyositis: a prospective multicentric study of 117 patients

BACKGROUND

Identification of myositis-specific autoantibodies (MSAs) for dermatomyositis (DM) could allow the characterization of an antibody-associated clinical phenotype.

OBJECTIVE

We sought to define the clinical phenotype of DM and the risk of cancer, interstitial lung disease (ILD) and calcinosis based on MSA.

METHODS

A 3.5-year multicentre prospective study of adult DM patients was conducted to determine the clinical phenotype associated with MSAs and the presence of cancer, ILD and calcinosis.

RESULTS

MSAs were detected in 47.1% of 117 included patients. Patients with antimelanoma differentiation-associated protein-5 antibodies (13.7%) had significantly more palmar violaceous macules/papules [odds ratio (OR) 9.9], mechanic's hands (OR 8), cutaneous necrosis (OR 3.2), articular involvement (OR 15.2) and a higher risk of ILD (OR 25.3). Patients with antitranscriptional intermediary factor-1 antibodies (11.1%), antinuclear matrix protein-2 antibodies (6.8%) and antiaminoacyl-transfer RNA synthetase (5.1%) had, respectively, significantly more poikiloderma (OR 5.9), calcinosis (OR 9.8) and articular involvement (OR 15.2). Cutaneous necrosis was the only clinical manifestation significantly associated with cancer (OR 3.1).

CONCLUSION

Recognition of the adult DM phenotype associated with MSAs would allow more accurate appraisal of the risk of cancer, ILD and calcinosis.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Improving the spatial and statistical accuracy in X-ray Raman scattering based direct tomography

An algorithm to simultaneously increase the spatial and statistical accuracy of X-ray Raman scattering (XRS) based tomographic images is presented. Tomography that utilizes XRS spectroscopy signals as a contrast for the images is a new and promising tool for investigating local atomic structure and chemistry in heterogeneous samples. The algorithm enables the spatial resolution to be increased based on a deconvolution of the optical response function of the spectrometer and, most importantly, it allows for the combination of data collected from multiple analyzers and thus enhances the statistical accuracy of the measured images.

Chitin-Prussian blue sponges for Cs(I) recovery: from synthesis to application in the treatment of accidental dumping of metal-bearing solutions

Prussian blue (i.e., iron[III] hexacyanoferrate[II], PB) has been synthesized by reaction of iron(III) chloride with potassium hexacyanoferrate and further immobilized in chitosan sponge (cellulose fibers were added in some samples to evaluate their impact on mechanical resistance). The composite was finally re-acetylated to produce a chitin-PB sponge. Experimental conditions such as the freezing temperature, the content of PB, the concentration of the biopolymer and the presence of cellulose fibers have been varied in order to evaluate their effect on the porous structure of the sponge, its water absorption properties and finally its use for cesium(I) recovery. The concept developed with this system consists in the absorption of contaminated water by the composite sponge, the in situ binding of target metal on Prussian blue load and the centrifugation of the material to remove treated water from soaked sponge. This material is supposed to be useful for the fast treatment of accidental dumping of Cs-contaminated water.

Rapid, automated imaging of mouse articular cartilage by microCT for early detection of osteoarthritis and finite element modelling of joint mechanics

OBJECTIVE

Mouse articular cartilage (AC) is mostly assessed by histopathology and its mechanics is poorly characterised. In this study: (1) we developed non-destructive imaging for quantitative assessment of AC morphology and (2) evaluated the mechanical implications of AC structural changes.

METHODS

Knee joints obtained from naïve mice and from mice with osteoarthritis (OA) induced by destabilization of medial meniscus (DMM) for 4 and 12 weeks, were imaged by phosphotungstic acid (PTA) contrast enhanced micro-computed tomography (PTA-CT) and scored by conventional histopathology. Our software (Matlab) automatically segmented tibial AC, drew two regions centred on each tibial condyle and evaluated the volumes included. A finite element (FE) model of the whole mouse joint was implemented to evaluate AC mechanics.

RESULTS

Our method achieved rapid, automated analysis of mouse AC (structural parameters in <10 h from knee dissection) and was able to localise AC loss in the central region of the medial tibial condyle. AC thickness decreased by 15% at 4 weeks and 25% at 12 weeks post DMM surgery, whereas histopathology scores were significantly increased only at 12 weeks. FE simulations estimated that AC thinning at early-stages in the DMM model (4 weeks) increases contact pressures (+39%) and Tresca stresses (+43%) in AC.

CONCLUSION

PTA-CT imaging is a fast and simple method to assess OA in murine models. Once applied more extensively to confirm its robustness, our approach will be useful for rapidly phenotyping genetically modified mice used for OA research and to improve the current understanding of mouse cartilage mechanics.

[Prevalence of cancer in the Afro-Caribbean population presenting dermatomyositis and anti-synthetase syndrome: a preliminary study conducted at Pointe-à-Pitre University Hospital, 2000-2012]

BACKGROUND

An association with cancer is described in 17-32% of cases of dermatomyositis (DM) and in 5-16% of cases of anti-synthetase syndrome (ASS). The literature contains very few studies involving Afro-Caribbean patients with DM or ASS. The aim of our retrospective study was to determine the prevalence of cancer in a series of patients with DM or ASS at the University Hospital of Pointe-à-Pitre between 1st January 2000 and 31st December 2012. The secondary objective was to review the clinical and laboratory features as well as the course of DM/ASS in these patients.

PATIENTS AND METHODS

The inclusion criteria were as follows: Afro-Caribbean origin; age >15 years; patient living in Guadeloupe; screening for malignancy.

RESULTS

Twenty-two patients were included (15 DM, 7 ASS). Only one case of cancer was diagnosed in the entire study population at a mean follow-up of 6 ± 4 years (prevalence: 6.7%, CI95% [1.7-31.9]). Of the 15 patients presenting DM (sex ratio F/M: 4, mean age: 45 ± 14 years), 6 (40%) had associated connective tissue disease.

CONCLUSION

Our study suggests a weak association between DM and cancer in Afro-Caribbean patients. These results may be explained by the features of the disease seen in these patients (female gender, young age at onset, associated connective tissue disease) and the low prevalence in the Caribbean region of cancers typically associated with DM.

Leukaemia in young children in the vicinity of British nuclear power plants: a case-control study

Background:

Concern about the risk of leukaemia in children living near nuclear power plants (NPPs) persists. Previous British analyses have been area based and consequently thought to be less effective than case–control studies.

Methods:

Cases of childhood leukaemia and non-Hodgkin lymphoma (LNHL) born and diagnosed in Great Britain between 1962 and 2007, with matched cancer-free controls, were analysed by logistic regression to estimate the risk of residential proximity at birth and diagnosis to the nearest NPP, adjusting for relevant variables.

Results:

For 9821 children with LNHL under the age of 5 years, the estimated extra risk associated with residential proximity to an NPP at birth was negative—interpolated Odds Ratio (OR) at 5 km was 0.86 (0.49–1.52). The comparison of 10 618 children with LNHL under five with 16 760 similarly aged children with other cancers also gave a negative estimate of the extra risk of residential proximity at diagnosis—interpolated OR at 5 km was 0.86 (0.62–1.18).

Conclusion:

Our results show little evidence of an increase in risk of LNHL to children aged under 5 years from living in the vicinity of an NPP. Risk estimates are incompatible with comparable ones published in a recent German case–control study.

Immunological follow-up of patients with neuromyelitis optica: Is there a good biomarker?

A serial assessment of biomarkers related to disease activity could be clinically useful in some autoimmune diseases. Neuromyelitis optica (NMO) is a severe inflammatory disease of the optic nerves and spinal cord that can be associated with lupus erythematosus, Sjögren syndrome or myasthenia gravis. In this review, we discuss the existing data on the use of biomarkers of disease activity in NMO. A specific and pathogenic antibody (Ab) directed against aquaporin 4 (AQP4) was recently discovered in this disease. The relapses were frequently accompanied by a rise and immunosuppressive therapy by a decrease in serum anti-AQP4 Ab concentrations. However, this association is not strong enough to justify treatment changes based only on anti-AQP4 Ab level variations. This parameter might be helpful as a longitudinal biomarker but only if a threshold inducing a relapse and justifying a switch in therapy can be established. A link between disease severity and serum cytotoxicity against AQP4-expressing cells was proposed but has not yet been confirmed. Finally, the assessment of T cell immunity against AQP4 and specific cytokines could be future directions for research.

Perinatal characteristics and outcome of preterm singleton, twin and triplet infants in NSW and the ACT, Australia (1994-2005)

OBJECTIVE

To compare the perinatal characteristics, neonatal morbidity and mortality of preterm singletons, twins and triplets born at 22-31 weeks' gestation and admitted to neonatal intensive care units (NICU) in New South Wales and Australian Capital Territory between 1994 and 2005.

METHODS

Perinatal characteristics and neonatal outcome data were obtained from the regional NICUS data collection to test for a priori hypothesis. The 10 068 very premature infants studied included 7304 (72.5%) singletons, 2444 (24.2%) twins and 320 (3.2%) triplets.

RESULTS

Assisted conception was associated with a higher maternal age and increased twins and triplets admissions into NICU than spontaneous conceptions (twins OR 6.9, 95% CI 6.1 to 8.0; and triplets OR 35.6, 95% CI 27.6 to 45.8). Major neonatal morbidities were similar between the three groups of singletons, twins or triplets. While twins of 22-27 weeks' gestation (adjusted OR 1.39, 95% CI 1.12 to 1.72) had higher mortality compared with singletons, mortality only diverged below 24 weeks' gestation. Mortality was predicted by decreasing gestational age, male gender and lack of antenatal steroids, whereas assisted conception was protective against mortality (adjusted OR 0.69, 95% CI 0.57 to 0.86).

CONCLUSIONS

Assisted conception contributed to higher very premature NICU admissions of twins and triplets. Preterm twins at the very extreme of viability had higher mortality compared with singletons. The protective effect of assisted conception against mortality requires further research.

Hypocretinergic dysfunction in neuromyelitis optica with coma-like episodes

Devic's neuromyelitis optica (NMO) is a severe demyelinating disease of the central nervous system, often misdiagnosed as multiple sclerosis, and involving mainly optic nerves and the spinal cord. We report on a peculiar case of relapsing NMO with severe recurrent dysautonomia and hypersomnia, in which we had the opportunity to observe a dramatic decrease in hypocretin/orexin cerebrospinal fluid level.

Bismuth recovery from acidic solutions using Cyphos IL-101 immobilized in a composite biopolymer matrix

Impregnated resins prepared by the immobilization of an ionic liquid (IL, Cyphos IL-101, tetradecyl(trihexyl)phosphonium chloride) into a composite biopolymer matrix (made of gelatin and alginate) have been tested for recovery of Bi(III) from acidic solutions. The concentration of HCl slightly influenced Bi(III) sorption capacity. Bismuth(III) sorption capacity increased with IL content in the resin but non-linearly. Maximum sorption capacity reached 110-130mgBig(-1) in 1M HCl solutions. The mechanism involved in Bi recovery was probably an ion exchange mechanism, though it was not possible to establish the stoichiometric exchange ratio between BiCl(4)(-) and IL. Sorption kinetics were investigated through the evaluation of a series of parameters: metal concentration, sorbent dosage, type and size of sorbent particles and agitation speed. In order to reinforce the stability of the resin particles, the IL-encapsulated gels were dried; this may cause a reduction in the porosity of the resin particle and then diffusion limitations. The intraparticle diffusion coefficients were evaluated using the Crank's equation. Additionally, the pseudo-first-order and pseudo-second-order equations were systematically tested on sorption kinetics. Metal can be desorbed from loaded resins using either citric acid or KI/HCl solutions. The sorbent could be recycled for at least three sorption/desorption cycles.