["Rheuma (be-)greifen"- A multimodal teaching concept to improve rheumatology education for medical students]

BACKGROUND

The German Society for Rheumatology, through its campaign Rheuma2025, aims to improve student teaching in order to ensure patient care for rheumatological patients in the future.

OBJECTIVE

To assess whether a combination of traditional and innovative educational methods provide both an improvement in the quality of teaching and an increase in the attractiveness of rheumatology as a discipline.

MATERIAL AND METHODS

Establishment of the teaching concept "Rheuma (be-)greifen" consisting of five modules on patient history taking with acting patients, musculoskeletal ultrasound, arthrocentesis, 3D printing of pathological joints and virtual reality applications based on real patient cases in the curricular teaching of medical students.

RESULTS

The evaluation of the teaching concept with 93 students of medicine showed a consistently high acceptance of all modules, which were rated as very effective or rather effective. Direct patient-related modules, such as history taking with acting patients, musculoskeletal ultrasound and arthrocentesis, received even higher acceptance than the visualization methods utilizing 3D printing and virtual reality.

CONCLUSION

Innovative teaching methods can help to improve the acceptance of teaching in the field of rheumatology, especially when combined with classical teaching contents.

Genome dynamics and temperature adaptation during experimental evolution of obligate intracellular bacteria

Evolution experiments with free-living microbes have radically improved our understanding of genome evolution and how microorganisms adapt. Yet there is a paucity of such research focusing on strictly host-associated bacteria, even though they are widespread in nature. Here, we used the Acanthamoeba symbiont Protochlamydia amoebophila, a distant relative of the human pathogen Chlamydia trachomatis and representative of a large group of protist-associated environmental chlamydiae, as a model to study how obligate intracellular symbionts evolve and adapt to elevated temperature, a prerequisite for the pivotal evolutionary leap from protist to endothermic animal hosts. We established 12 replicate populations under two temperatures (20 °C, 30 °C) for 510 bacterial generations (38 months). We then used infectivity assays and pooled whole-genome re-sequencing to identify any evolved phenotypes and the molecular basis of adaptation in these bacteria. We observed an overall reduction in infectivity of the symbionts evolved at 30 °C, and we identified numerous nonsynonymous mutations and small indels in these symbiont populations, with several variants persisting throughout multiple time points and reaching high frequencies. This suggests that many mutations may have been beneficial and played an adaptive role. Mutated genes within the same temperature regime were more similar than those between temperature regimes. Our results provide insights into the molecular evolution of intracellular bacteria under the constraints of strict host dependence and highly structured populations and suggest that for chlamydial symbionts of protists temperature adaptation was facilitated through attenuation of symbiont infectivity as a trade-off to reduce host cell burden.

POS0260 LONG-TERM HUMORAL RESPONSE TO SARS-CoV-2 VACCINATION IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASE

Background

The first vaccine against SARS-CoV-2 was approved in December 2020. Immunogenicity of SARS-CoV2 vaccines in patients with immune-mediated inflammatory disease (IMID) have so far been evaluated in the 2-6 weeks following complete vaccination and risk groups for poor early vaccine response have been identified leading to specific vaccination recommendations. However, data on the long-term course and persistence of vaccine response in IMID patients, as well as the outcomes of the specific recommendations are lacking.

Objectives

To evaluate the long-term course of humoral response to SARS-CoV-2 vaccination in a large prospective cohort of IMID patients and non-IMID controls with a follow-up duration of up-to to 10 months after the first vaccine dose.

Methods

We have initiated a prospective dynamic cohort of IMID patients and healthy controls in February 2020 to monitor immune response to SARS-CoV-2 and respiratory infections including COVID-19 (1). Participants who contributed data starting from the 4 weeks before their first vaccination onwards were included in this analysis. Antibodies against SARS-CoV-2 spike protein were quantified with an ELISA from Euroimmun (Lübeck, Germany) with an optical density cutoff of 0.8. We fitted linear mixed-effect models for log-transformed antibody levels using time splines with adjustment for age and sex. Marginal mean antibody levels with 95% confidence intervals (CI) were estimated at selected time points for IMID patients and controls with double vaccination. We descriptively analyzed the observed antibody levels over time in cohort participants receiving two vaccinations vs. three vaccinations.

Results

Among 5076 cohort participants, 3147 IMID patients and healthy controls (mean (SD) age 49 (16)) provided 4756 samples for this analysis between December 2020 and 2021, with a median (IQR) 28 (14-31) weeks of follow-up after the first vaccination (Table 1). 2965 (94%) participants had received at least 2 and 223 (7%) participants had received three vaccine doses by the date of their latest sampling. In IMID patients, age and sex-adjusted estimated marginal mean antibody levels waned after week 16 and were substantially reduced at all time points compared to the controls, finally dropping to the borderline range (1.01, 95%CI 0.86 to 1.19) at week 40 (Figure 1A, Table 1). A third dose was given to 128 (7%) of IMID patients with a poor response to 2 vaccine doses after a median 20 weeks of the second dose (IQR 10 to 26 weeks). After the third dose, antibody levels in IMID patients were comparable to those of healthy controls at 40 weeks who had three vaccine doses. These were also higher than that of IMID patients and controls who did not receive a third dose (Figure 1B).

Table 1.

Participant characteristics and antibody levels

Healthy controlsIMID N11991948 Age, mean (SD)40.8 (13.5)54.3 (14.8) Follow-up, weeks, median (IQR)31.1 (23.8-36.6)19.6 (12.3-26.6) Follow-up range, weeks,1.6-46.11.7-46.3Sex, n(%) Female554 (46.2)1136 (58.3)Vaccine intervals, ´median (IQR) 1st to 2nd dose4.6 (3.0-6.0)6.0 (5.0-6.1) 2nd to 3rd dose29.6 (26.9-36.4)19.9 (10.0-26.1)Diagnosis, n (%) Spondyloarthritis-713 (36.6) Rheumatoid arthritis-489 (25.1) Autoimmune disease, systemic+-420 (21.5) Inflammatory bowel disease-219 (11.2) Psoriasis-107 (5.5)Mean* antibody levels after 1st dose Week-84.16 (3.89 to 4.45)2.97 (2.83 to 3.12) Week-168.39 (7.81 to 9.02)5.04 (4.81 to 5.28) Week-325.02 (4.73 to 5.33)2.52 (2.32 to 2.74) Week-402.14 (1.95 to 2.35)1.01 (0.86 to 1.19)

+ Systemic lupus, systemic sclerosis, Sjögren’s syndrome, vasculitis

* Estimated marginal means adjusted for age and sex.

Figure 1.

Conclusion

Humoral response to vaccination against SARS-CoV-2 was weaker in IMID patients compared to controls at all time points after the first vaccine dose and practically disappeared after 1 year. IMID patients can still achieve a good antibody response with a third dose even after a weak response with two doses.

References

[1]Simon D et al Nat Commun 2020

Disclosure of Interests

None declared

AB1528-HPR FULL BODY HAPTIC BODYSUIT - AN INSTRUMENT TO MEASURE THE RANGE AND SPEED OF MOTION IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS (axSpA) - PRELIMINARY RESULTS

Background

Movement of the spine is restricted in axial spondyloarthritis (axSpA) [1]. Spine function is usually assessed by the Bath Ankylosing Spondylitis Metrology Index (BASMI), which is based on a limited set of defined motions that are measured semiquantitatively in the spatial dimension but not in the temporal dimension. Sensor-based measurement of spine function in axSpA patients is in its infancy but may provide a deeper and more detailed understanding of the impact of axSpA on the impairment of spine function [2,3]. In theory, unbiased full body assessment of spine motion may open a new dimension in function analysis in axSpA.

Objectives

To test if a of a full-body based haptic capturing of spine motion is technically feasible and can pick up the measurements of BASMI items 1-5. Furthermore, we aimed to investigate whether such measurements are accurate and reproducible comparing to BASMI scores done by rheumatologists. Lastly, we sought to measure velocity of spine movements to allow spatiotemporal analysis of motion.

Methods

For full-body haptic assessment of spine motion a full-body haptic suit (Teslasuit; VR Electronics Ltd, London) was used that consists of a smart textile two-piece bodysuit that not only captures range and speed of motion but also provides biometric and haptic feedback. This device is currently tested in clinical trials (https://teslasuit.io/rehabilitation/) but has not been tested in rheumatic diseases such as axSpA [4]. Since there is no pre-defined technical solution for measuring BASMI, we used the integrated inertial measurement units (IMUs) of the suit (Figure 1a). The suit is recording the position and rotations of its IMUs and is transforming the raw data to position coordinates and joint angle of the bones. We implemented an algorithm that is accessing the sensor data and is calculating the BASMI measurements as well as velocity. Assessment were done in healthy individuals. BASMI was obtained 3 times by teslasuit followed by standard BASMI measurement by 2 independent rheumatologists. In addition, rotational movements with their maximum torso speed to evaluate angular velocity were performed (Figure 1b). Measurements were compared using absolute values and relative standard deviation (which is the standard deviation normalized by the mean).

Results

Five healthy individuals (all males, age: 27.6 ± 1.8 years, height: 178 ± 5 cm; weight 70.0 ± 8.0 kg) were assessed. Teslasuit measurements were well tolerated. Technically, we were able to calculate BASMI item 3 and 5, finger-to-floor distance and the velocity of the spine movement using the position data of hand, talus and upper back sensors (Figure 1a, b). Due to absence of sensors at the head and the required back areas, BASMI 1, 2, 4 could only partially be captured and require further programming, which is currently performed. Only marginal differences were detected regarding the relative standard deviations of measurements between teslasuit and rheumatologists (BASMI 3: rheumatologists 8,5%: suit 10%; BASMI 5: rheumatologists 5,4%: suit 4,9%) (Figure 1c). The speed of spinal motion could be measured with an average angular velocity of 172.2 degrees/sec over the entire rotation motion and an average maximum angular velocity of 417.2 degrees/sec.

Conclusion

This study shows that full-body haptic-suits can capture spinal motion including parts of the BASMI score. In addition, they allow to measure the speed of spinal movement, which might be an important and so far unrecognized factor to test the impact of axSpA on spinal function. Based on these results, full-body haptic-suits will be tested in axSpA patients in the future. Furthermore, technical solutions are currently developed to implement the remaining BASMI scores into the suit as well as connections from the suit to virtual reality devices for patients and doctors.

References

[1]Sieper, J. and D. Poddubnyy, Axial spondyloarthritis. Lancet 2017.

[2]Gardiner, P.V., et al., Rheumatology (Oxford) 2020.

[3]Kiefer, D., et al., S J Rheumatol 2022.

[4]Caserman, P. et al Sensors (Basel) 2021.

Acknowledgements

This work was (partly) funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB 1483 – Project-ID 442419336, EmpkinS.

Disclosure of Interests

None declared

AB0385 BARICITINIB LEADS TO RAPID AND PERSISTENT RESOLUTION OF SYNOVITIS AS MEASURED BY HAND MRI IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS (RA) FAILING cs/bDMARD THERAPY

Background

RA is characterized by synovial inflammation resulting in local bone loss [1]. Inhibitors of JAK/Stat pathways, such as baricitinib, demonstrated efficacy in reducing signs and symptoms of RA in clinical trials, however, little is known about their effects on synovitis and bone structure [2]. Preclinical and clinical observations suggest a positive effect JAK inhibitors on bone mass and microstructure, however no prospective, interventional clinical trial has been performed so far [3].

Objectives

The aim of this study is to evaluate the effect of baricitinib on local inflammation (synovitis and osteitis) and bone structure (erosions) in RA patients failing on cs/bDMARD therapy using hand MRI.

Methods

BAREBONE is a prospective, interventional, open label, monocentric single center study (EUDRACT 2018-001164-32 / NCT03701789) to assess the effect of baricitinib (4mg/day) on local MRI inflammation and structure in patients with active RA. Besides demographic and clinical characteristics, hand joint inflammation was assessed by magnetic resonance imaging (MRI) using a 1.5 Tesla scanner (Siemens Magnetom Aera T1w TSE cor, T2w TIRM cor, T2w TSE fat-sat trans, T1w TSE fat-sat trans + cor after KM;). at baseline, week 24 and week 48. Scans were assessed for synovitis, osteitis and bone erosions using the RAMRIS scoring system using two independent blinded readers (SK and SB). Intraclass correlation coefficients were calculated for total RAMRIS and synovitis, erosion and osteitis subscores and in a second step differences between cs and bDMARD failure were elaborated. Variables are summarized descriptively using means and 95% bootstrap confidence intervals for continuous outcomes and as number and percentages for categorical outcomes.

Results

Thirty- two RA patients were screened and 30 patients were included (age: 53.4 [SD 12.6] years; sex: f/m N 24/6; disease duration: 3 [IQR 2.0 – 8.0] years; biologic naïve/bDMARD failure 16/14). 27 patients completed the trial while MRI data was available for 24 patients at week 48. Demographics and clinical characteristics can be seen in Table 1. Total RAMRIS scores slightly decreased from 20.6 (95% CI 14.4 -27.8) at baseline (BL) to 18.3 (11.5 -26.5) at week 48. The synovitis subscore mainly contributed to total RAMRIS reduction by significantly improving from 5.3 (4.0 - 6.8) at BL to 2.7 (1.5 - 4.0) at week 48 with a score change of -2.9 (-4.0 to -1.8). At week 48, 12 patients (44.4%) had no signs of synovitis compared to only 3 patients at BL. In contrast, RAMRIS osteitis subscores only marginally decreased from 4.9 (2.2 - 8.4) at BL to 4.0 (1.9 - 6.7) at week 48. RAMRIS erosion score remained stable over the 48-week observation time. A significant difference in RAMRIS synovitis change for biologic naïve -3.8 (-5.2 to -2.6) vs biologic failure -1.0 (-2.2 to 0.4 could be observed at week 48).

With respect to clinical disease activity, DAS 28 score decreased from 4.8 (4.5 – 5.1) at BL to 2.9 (2.5 – 3.3) at week 48. Detailed results can be found in Table 1 and Figure 1. Intraclass coefficient (95%CI) for RAMRIS scoring was high for both readers 0.997 (0.994 to 0.998).

Table 1.

Demographics, DAS 28 ESR, RAMRIS total score and RAMRIS subset scores at baseline, week 24 and week 48 are shown as well as number of patients with improvement and resolution of synovitis.

BaselineWeek 24Week 48N303027AgeMean [SD]53.5 (12.6)Genderfemalen [%]24 (80.0)malen [%]6 (20.0)Disease duration, yearsMedian (IQR)3.0 (2.0-8.0)DAS-28 ESRMean [95%CI]4.8 (4.5 to 5.1)3.0 (2.7 to 3.3)2.7 (2.4 to 3.0)MRI availablen [%]30 (100.0)28 (93.3)24 (88.9)RAMRIS totalMean [95%CI]20.6 (14.4 to 27.6)18.4 (12.6 to 25.4)18.3 (11.5 to 26.5)RAMRIS total changeMean [95%CI]0.0 (0.0 to 0.0)-2.1 (-4.0 to -0.4)-3.9 (-7.2 to -0.5)RAMRIS synovitisMean [95%CI]5.3 (3.9 to 6.9)3.5 (2.2 to 4.9)2.7 (1.5 to 4.0)RAMRIS synovitis changeMean [95%CI]0.0 (0.0 to 0.0)-1.8 (-2.5 to -1.0)-2.9 (-4.0 to -1.8)RAMRIS synovitis improvedpatients n [%]10 (33.3)13 (48.1)RAMRIS synovitis resolvedpatients n [%]10 (33.3)12 (44.4)RAMRIS osteitisMean [95%CI]4.9 (2.2 to 8.4)3.7 (1.5 to 6.2)4.0 (1.9 to 6.7)RAMRIS osteitis changeMean [95%CI]0.0 (0.0 to 0.0)-0.9 (-3.1 to 1.0)-1.9 (-5.7 to 1.1)RAMRIS osteitis improvedpatients n [%]2 (6.7)4 (14.8)RAMRIS erosionMean [95%CI]10.4 (7.3 to 14.6)11.2 (7.7 to 15.0)11.6 (7.5 to 16.6)RAMRIS erosion changeMean [95%CI]0.0 (0.0 to 0.0)0.6 (0.1 to 1.2)0.9 (0.0 to 2.1)RAMRIS erosion worsenedpatients n [%]2 (6.7)3 (11.1)

Conclusion

Our study shows that baricitinib primarily reduces MRI synovitis in RA patients that have previously failed csDMARD and bDMARD therapy and particularly in patients who are biologic naïve.

References

[1]McInnes, I.B. and G. Schett, The pathogenesis of rheumatoid arthritis. N Engl J Med, 2011.

[2]Genovese, M.C., et al., Baricitinib in Patients with Refractory Rheumatoid Arthritis. N Engl J Med, 2016

[3]Adam, S., et al., JAK inhibition increases bone mass in steady-state conditions and ameliorates pathological bone loss by stimulating osteoblast function. Sci Transl Med, 2020.

Acknowledgements

Lilly Deutschland GmbH funded the Barebone trial

Disclosure of Interests

Stephan Kemenes: None declared, Sara Bayat: None declared, David Simon Speakers bureau: Lilly Pharma Deutschland GmbH, Janssen, Consultant of: BMS, Pfizer, Sanofi, Abbvie, Janssen, Medac, Novartis,

Lilly Deutschland GmbH, GileaBMS, Pfizer, Sanofi, Abbvie, Janssen, Medac, Novartis,

Lilly Deutschland GmbH, Gilead, Amgen

d,

, Grant/research support from: Novartis, Gilead, Abbvie, Lilly, Gerhard Krönke Speakers bureau: GSK, Novartis, Consultant of: GSK, Lilly, Novartis, Janssen, Grant/research support from: Lilly, Novartis, BMS, Janssen, Daniela Bohr: None declared, Larissa Valor: None declared, Fabian Hartmann: None declared, Louis Schuster: None declared, Koray Tascilar Speakers bureau: Gilead speaker, Consultant of: UCB, Lilly, Georg Schett Speakers bureau: Janssen, Abbvie, BMS, Lilly, Novartis, Roche, AMGEN, Gilead, UCB, Consultant of: Lilly, Novartis, Abbvie, Grant/research support from: Chugai, Lilly, Novartis, Arnd Kleyer Speakers bureau: Lilly, Novartis, Abbvie, Consultant of: BMS, Pfizer, Sanofi, Abbvie, Janssen, Medac, Novartis,

Lilly Deutschland GmbH, Gilead, Amgen

, Grant/research support from: Novartis, Lilly Deutschland GmbH, Gilead

POS1545-HPR PATIENT SELF-SAMPLING IN RHEUMATOID ARTHRITIS: RESULTS FROM A RANDOMIZED CONTROLLED TRIAL

Background

Rheumatoid arthritis (RA) requires early diagnosis and tight surveillance of disease activity. Patient self-sampling of blood for the analysis of autoantibodies and inflammation markers could facilitate the identification of patients at-risk for RA and improve tight disease monitoring [1].

Objectives

A randomized, controlled trial to evaluate the feasibility, acceptability and accuracy of an upper arm self-sampling device (UA) and finger prick-test (FP) to measure capillary blood from RA patients for C-reactive protein (CRP) levels and the presence of IgM rheumatoid factor (RF IgM) and anti-cyclic citrullinated protein antibodies (anti-CCP IgG).

Methods

50 RA patients were randomly assigned in a 1:1 ratio to self-collection of capillary blood via UA or FP. Venous blood sampling (VBS) was performed as gold standard in both groups to assess the concordance of CRP levels as well as RF IgM and CCP IgG. General acceptability and pain during sampling were measured and compared between UA, FP and VBS. The number of attempts for successful sampling, requests for assistance, volume and duration of sample collection were also assessed.

Results

49/50 (98%) patients were able to successfully collect capillary blood. Overall agreement between capillary and venous analyses for CRP (0.992), CCP IgG (0.984) and RF IgM (0.994) were good. In both groups 4/25 (16%) needed a second attempt and 8/25 (32%) in the UA and 7/25 (28%) in the FP group requested assistance. Mean pain scores for capillary self-sampling (1.7/10 ± 1.1 (UA) and 1.9/10 ± 1.9 (FP)) were lower on a numeric rating scale compared to venous blood collection (UA: 2.8/10 ± 1.7; FP: 2.1 ± 2.0). UA patients were more likely to promote the use of capillary blood sampling (net promoter score: +28% vs. -20% for FP) and were more willing to perform blood collection at home (60%) vs. 32% for FP).

Conclusion

This study shows that self-sampling is accurate, feasible and well accepted among patients. The implementation could allow tight remote monitoring of disease activity as well as identifying patients at-risk for RA and potentially other rheumatic diseases.

References:

[1]Knitza J, Knevel R, Raza K, Bruce T, Eimer E, Gehring I, et al. Toward Earlier Diagnosis Using Combined eHealth Tools in Rheumatology: The Joint Pain Assessment Scoring Tool (JPAST) Project. JMIR Mhealth Uhealth. 2020;8:e17507.

Acknowledgements

We thank all patients for their participation in this study. This study is part of the PhD thesis of the first author JK (AGEIS, Université Grenoble Alpes, Grenoble, France). We thank Josefine Born and Deniz Krämer for their help recruiting patients.

Disclosure of Interests

Johannes Knitza Grant/research support from: Thermo Fisher Scientific, Novartis, Koray Tascilar: None declared, Nicolas Vuillerme: None declared, Ekaterina Vogt Employee of: Thermo Fisher Scientific, Paul Matusewicz Employee of: Thermo Fisher Scientific, Giulia Corte: None declared, Louis Schuster: None declared, Timothée Aubourg: None declared, Gerlinde Bendzuck: None declared, Marianne Korinth: None declared, Corinna Elling-Audersch: None declared, Arnd Kleyer: None declared, Sebastian Boeltz: None declared, Axel Hueber: None declared, Gerhard Krönke: None declared, Georg Schett: None declared, David Simon: None declared

Playing alone: can game design elements satisfy user needs in gamified mHealth services?

Chronic health conditions have necessitated the need for behavioral interventions (such as exercise programs) outside of clinical contexts, increasingly managed through technology such as mobile health (mHealth) services. Gamification has emerged as a promising tool to facilitate greater engagement in these services; however, no studies investigate the links between specific game design elements (GDEs) and psychological or behavioral outcomes within a health context. This domain is motivationally complex and has shown resistance to the satisfaction of social (relatedness) needs, presenting a challenge to the design of gamification products for health promotion. Drawing on self-determination theory, this research demonstrates the strengths of a taxonomy based upon structural features of GDEs (such as social, narrative or reward elements) rather than the design intent definitions of these elements used in previous studies. This taxonomy is then used to assess the relationship between GDEs and psychological needs satisfaction in a survey (N = 236) of gamified exercise/fitness application users. Further qualitative interviews (N = 20) were conducted to clarify survey findings. This research demonstrates the positive association between control and presentation elements and autonomy satisfaction, and control and reward elements and competency satisfaction. However, it also suggests that player type and context may limit the ability for GDEs alone to support relatedness satisfaction in mHealth services. Implications for managers and researchers are discussed, particularly the strengths and weaknesses of using structural taxonomies in gamification assessment.

Carbon-dependent growth, community structure and methane oxidation performance of a soil-derived methanotrophic mixed culture

Soil-borne methane-oxidizing microorganisms act as a terrestrial methane (CH4) sink and are potentially useful in decreasing global CH4 emissions. Understanding the ecophysiology of methanotrophs is crucial for a thorough description of global carbon cycling. Here, we report the in situ balance of soils from abandoned landfills, meadows and wetlands, their capacities to produce and oxidize CH4 at laboratory-scale and the isolation of a soil-borne methanotrophic-heterotrophic mixed culture that was used for carbon (C1 and C2) feeding experiments. We showed that even with similar soil properties, the in situ CH4 balance depends on land-use. Different soils had different potentials to adapt to increased CH4 availability, leading to the highest CH4 oxidation capacities for landfill and wetland soils. The most efficient mixed culture isolated from the landfill was dominated by the methanotrophs Methylobacter sp. and Methylosinus sp., which were accompanied by Variovorax sp. and Pseudomonas sp. and remained active in oxidizing CH4 when supplied with additional C-sources. The ratios between type I and type II methanotrophs and between methanotrophic and heterotrophic bacteria changed when C-sources were altered. A significant effect of the application of the mixed culture on the CH4 oxidation of soils was established but the extent varied depending on soil type.

POS1394 ACCURACY AND PERFORMANCE OF A HANDHELD ULTRASOUND DEVICE TO ASSESS ARTICULAR AND PERIARTICULAR PATHOLOGIES IN PATIENTS WITH INFLAMMATORY ARTHRITIS

Background:

Handheld ultrasound (HHUS) devices have increasingly found their way into clinical practice due to several advantages (e.g. portability, significantly lower purchase cost). However, there is no evidence to date on the accuracy and performance of HHUS in patients with inflammatory arthritis (IA).

Objectives:

To assess accuracy and performance of a new HHUS machine in comparison to a conventional cart-based sonographic machine in patients with IA.

Methods:

Consecutive IA patients of our outpatient clinic with at least one tender and swollen joint in the 66/68 joint count were enrolled. US was performed on clinically affected joints with corresponding tendons/entheses using a cart-based sonographic device (“Samsung HS40”) and a HHUS device (“Butterfly iQ”) in standard scan positions. One blinded reader scored all images for the presence of following pathologic findings: erosions, bony enlargement, synovial hyperthrophy, joint effusion, bursitis, tenosynovitis and enthesitis. In addition, synovitis was graded (B Mode and power Doppler (PD)) by the 4-level EULAR-OMERACT scale [1]. To avoid bias by the blinded reader, who otherwise would have been tempted to identify pathological findings for each examined joint, we also included 67 joints of two healthy volunteers into the evaluation. We calculated the overall concordance and the concordance by type of joint and type of pathological finding between the two devices (percentage of observation pairs in which the same rating was given by both devices). The Cohen’s kappa coefficient (κ) with 95% bootstrap confidence intervals was used to assess the agreement between the two US devices. We also measured the time required for the US examination of one joint with both devices.

Results:

32 patients (20 rheumatoid arthritis, 10 psoriatic arthritis, 1 gouty arthritis, 1 systemic lupus erythematosus) were included in this study. Mean age of patients was 58.2±13.7 years, 63% were females. In total 186 joints were examined. The overall raw concordance in B-mode between the two devices was 97 %, with an overall κappa for agreement of 0.90, 95% CI (0.89, 0.94). No significant differences were found in relation to type of joint or pathological finding examined. The PD-mode of the HHUS device did not detect any PD-signal, whereas the cart-based device detected a PD-signal in 61 joints (33%). The portable device did not offer any time saving compared to the cart-based device (mean time in seconds per examined region: 47 seconds for the HHUS device versus 46.3 seconds for the cart-based device).

Conclusion:

The HHUS device “Butterfly iQ” has been shown to be accurate in the assessment of structural joint damage and inflammation in patients with IA, but only in B-mode. Significant improvements are still needed to reliable demonstrate blood flow detection by PD mode.

References:

[1]D’Agostino, M.A., et al., RMD Open, 2017. 3(1): p. e000428.

Table 1.

Concordance between a handheld and a conventional cart-based US device in B-mode

Agreement by siteN joints (%)Concordance (%)Kappa 95%CIOverall186970.90 (0.89 to 0.94)Wrist32 (17.2)960.86 (0.77 to 0.93)Finger/toe joint (MCP, PIP, DIP, MTP)114 (61.3)970.92 (0.88 to 0.95)Elbows11 (5.9)950.87 (0.75 to 0.97)Shoulder4 (2.2)1001.00 (NA to NA) *Knee20 (10.7)980.96 (0.90 to 1.00)Ankle5 (2.7)1001.00 (NA to NA) *Agreement by pathological findingJoint effusion950.81 (0.68 to 0.92)Synovitis940.87 (0.79 to 0.93)Synovitis OMERACT grade (0– 3)900.84 (0.76 to 0.91)Bone enlargement980.88 (0.71 to 1.00)Erosion980.89 (0.77 to 0.89)Tenosynovitis980.83 (0.61 to 0.96)Entheseopathy1001.00 (NA to NA) *Bursitis970.90 (0.89 to 0.94)

* unreliable kappa statistics because of small number of shoulders/ankles examined and small number of entheseopathies

Figure 1.

Pathological US findings in MCP joints (1, 2, 3) and wrist (4) depicted by the two different ultrasound devices

B-mode erosive (arrow) and synovial (asterisk) changes could be detected by both devices (1-2), while PD changes of different grades only by the conventional US device (3-4).

Acknowledgements:

This study was supported by the Deutsche Forschungsgemeinschaft (DFG- FOR2886 PANDORA and the CRC1181). Additional funding was received by the Bundesministerium für Bildung und Forschung (BMBF; project METARTHROS, MASCARA), the H2020 GA 810316 - 4D-Nanoscope ERC Synergy Project, the IMI funded project RTCure, the Emerging Fields Initiative MIRACLE of the Friedrich-Alexander-Universität Erlangen-Nürnberg, the Else Kröner-Memorial Scholarship (DS, no. 2019_EKMS.27) and Innovationsfond Lehre / FAU Erlangen-Nürnberg 2019.

Disclosure of Interests:

None declared

POS1492-HPR EVALUATION OF A VIRTUAL REALITY-BASED APPLICATION TO EDUCATE HEALTHCARE PROFESSIONALS AND MEDICAL STUDENTS ABOUT INFLAMMATORY ARTHRITIS

Background:

Inflammatory arthritides (IA), such as rheumatoid arthritis or psoriatic arthritis, are disorders that can be difficult to comprehend for health professionals and students in terms of the heterogeneity of clinical symptoms and pathologies. New didactic approaches using innovative technologies such as Virtual Reality (VR) applications could be helpful to demonstrate disease manifestations as well as joint pathologies in a more comprehensive way. However, the potential of using a VR education concept in IA has not yet been evaluated.

Objectives:

We evaluated the feasibility of a VR application to educate healthcare professionals and medical students about IA.

Methods:

We developed a VR application using IA patients data as well as two- and three-dimensional visualized pathological joints from X-ray and computed tomography generated images (1). This VR application (called Rheumality) allows the user to interact with representative arthritic joint and bone pathologies of IA patients (Figure 1 A, B). In a consensus meeting an online questionnaire was designed to collect basic demographic data (age, sex), profession of the participants, and their feedback on the general impression, knowledge gain and potential areas of application of the VR application. The VR application was subsequently tested and evaluated by healthcare professionals (physicians, researchers, and other healthcare professionals) and medical students at predefined events (two annual rheumatology conferences and academic teaching seminars at two sites in Germany).

Results:

125 individuals participated in this study (56% female, 43% male, 1% non-binary). 59% of the participants were between 18-30 years of age, 18% between 31-40, 10% between 41-50, 8% between 51-60 and 5% were between 61-70. Of the participants, 50 were physicians, five researchers and four other health care professionals, the remaining were medical students (66). The participants rated the application as excellent (Figure 1 C, D), the mean rating of the VR application was 9.0/10 (SD 1.2) and many participants would recommend the use of the application, with a mean recommendation score of 3.2/4 (SD 1.1). A large majority stated that the presentation of pathological bone formation improves the understanding of the disease (120 out of 125 (96%)).

Conclusion:

The data show that IA-targeting innovative teaching approaches based on VR technology are feasible. The use of VR applications enables a disease-specific knowledge visualization and may add a new educational pillar to conventional educational approaches.

References:

[1]Kleyer A et al. Z Rheumatol 78, 112–115 (2019)

Figure 1.

Illustration of the VR application and evaluation results

Two- and three-dimensional visualized pathological joints from X-ray and computed tomography generated images in a patient with long-standing (inadequately treated) RA (A) and a patient with early RA (B). Overall rating (range 0-10) on the VR application divided into four different professional subgroups (C); recommendations of VR application in the four different professional subgroups (D). HC, health care professionals; Boxplot explanation: Crossbars represent medians, whiskers represent 5-95 percentiles (points below the whiskers are drawn as individual points), box always extends from the 25th to 75th percentiles (hinges of the plot).

Disclosure of Interests:

Philipp Klemm Consultant of: Lilly Deutschland GmbH, Arnd Kleyer Speakers bureau: Lilly Deutschland GmbH, Consultant of: Lilly Deutschland GmbH, Grant/research support from: Lilly Deutschland GmbH, Koray Tascilar: None declared, Louis Schuster: None declared, Timo Meinderink: None declared, Florian Steiger: None declared, Uwe Lange: None declared, Ulf Müller-Ladner: None declared, Johannes Knitza Speakers bureau: Lilly Deutschland GmbH, Philipp Sewerin Speakers bureau: Lilly Deutschland GmbH, Paid instructor for: Lilly Deutschland GmbH, Johanna Mucke Consultant of: Lilly Deutschland GmbH, Alexander Pfeil Speakers bureau: Lilly Deutschland GmbH, Paid instructor for: Lilly Deutschland GmbH, Consultant of: Lilly Deutschland GmbH, Georg Schett: None declared, Fabian Hartmann Consultant of: Lilly Deutschland GmbH, Axel Hueber Consultant of: Lilly Deutschland GmbH, Grant/research support from: Lilly Deutschland GmbH, David Simon Speakers bureau: Lilly Deutschland GmbH, Paid instructor for: Lilly Deutschland GmbH, Consultant of: Lilly Deutschland GmbH, Grant/research support from: Lilly Deutschland GmbH

OP0051 STRUCTURAL ENTHESEAL LESIONS IN PSORIASIS PATIENTS ARE ASSOCIATED WITH AN INCREASED RISK OF PROGRESSION TO PSORIATIC ARTHRITIS - A PROSPECTIVE COHORT STUDY

Background:

We have previously reported that the presence of musculoskeletal pain in psoriasis patients is associated with a higher risk of developing psoriatic arthritis (PsA) (1). Furthermore, a subset of psoriasis patients shows evidence for structural entheseal lesions (SEL) in their hand joints (2), sometimes also referred as “Deep Koebner Phenomenon”, which are highly specific for psoriatic disease and virtually absent in healthy controls, rheumatoid arthritis and hand osteoarthritis patients (2-4). However, it remains unclear whether SEL alone or in combination with musculoskeletal pain are associated with the development of PsA.

Objectives:

To test whether the presence of SEL in psoriasis patients increases the risk for progression to PsA and how this is related to the presence of musculoskeletal pain.

Methods:

Psoriasis patients without evidence of PsA were enrolled in a prospective cohort study between 2011 and 2018. All patients underwent baseline assessment of SEL in their 2ndand 3rdMCP joints by high-resolution peripheral quantitative computed tomography (HR-pQCT). The risk of PsA development associated with SEL and arthralgia was explored using survival analyses and multivariable Cox regression models.

Results:

114 psoriasis patients (72 men/42 women) with a mean (SD) follow-up duration of 28.2 (17.7) months were included, 24 of whom developed PsA (9.7 /100 patient-years, 95%CI 6.2 to 14.5) during the observation period. Patients with SEL (N=41) were at higher risk of developing PsA compared to patients without such lesions (21.4/100 patient-years, 95%CI 12.5 to 34.3, HR 5.10, 95%CI 1.53 to 16.99, p=0.008) (Kaplan Meier plot A). Furthermore, while patients without arthralgia and without SEL had a very low progression rate to PsA (1/29; 3.4%), patients with arthralgia but no SEL showed higher progression (5/33; 15.2%), which was in line with previous observations (1) (Kaplan Meier plot B). Presence of SEL further enhanced the risk for progression to PsA both in the absence (6/16; 37.5%) and presence (6/14; 42.8%) of arthralgia with the highest progression rate in those subjects with both arthralgia and SEL (p<0.001 by log rank test for trend) (Kaplan Meier plot B).

Conclusion:

Presence of SEL is associated with an increased risk of developing PsA in patients with psoriasis. If used together with pain, SEL allow defining subsets of psoriasis patients with very low and very high risk to develop PsA.

References:

[1]Faustini F et al. Ann Rheum Dis. 2016;75:2068-2074

[2]Simon D et al. Ann Rheum Dis. 2016;75:660-6

[3]Finzel S et al. Ann Rheum Dis. 2011;70:122-7

[4]Finzel S et al. Arthritis Rheum. 2011;63:1231-6

Disclosure of Interests:

David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Koray Tascilar: None declared, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Sara Bayat Speakers bureau: Novartis, Eleni Kampylafka Speakers bureau: Novartis, BMS, Janssen, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Louis Schuster: None declared, Klaus Engel: None declared, Michael Sticherling Grant/research support from: Novartis, Consultant of: Advisory boards Abbvie, Celgene, Janssen Cilag, Lilly, Pfizer, MSD, Novartis, Amgen, Leo, Sanofi, UCB, Speakers bureau: Abbvie, Celgene, Janssen Cilag, Leo, MSD, Novartis, Pfizer, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB

A Theory-Driven Investigation of the Association Between Emotion Dysregulation and Suicide Risk in a Clinical Adolescent Sample

OBJECTIVE

Emotion dysregulation has been consistently linked to suicide ideation and attempt, but an explanatory model for this relationship has not been adequately investigated in adolescents. This study examined the concurrent relationship among emotion dysregulation, variables from the Interpersonal-Psychological Theory of Suicide (IPTS), and suicide risk (operationalized as a continuous variable that increases in intensity from nonspecific to active suicide ideation to suicide ideation with a plan) in a clinical adolescent sample.

METHOD

A total of 151 adolescents (aged 12-17) were recruited from an inpatient psychiatry unit. Cross-sectional analyses were conducted to determine whether the relationship between emotion dysregulation and suicide risk was explained by the variables of perceived burdensomeness (PB), thwarted belongingness, and capability for suicide, as proposed by the IPTS.

RESULTS

As hypothesized, the relationship between emotion dysregulation and suicide risk was explained by PB and capability for suicide. Depressive symptoms had an independent relationship with suicide risk after controlling for IPTS variables.

CONCLUSIONS

The results from this study suggest that effective treatment strategies that reduce negative cognition tied to PB and depressive symptoms would address the most proximal variables related to suicide risk in adolescents. Enhancing emotion management would serve to maintain low levels of proximal influences on risk.

Understanding caregivers' intentions for their child to walk to school: Further application of the theory of planned behavior

Increases in childhood obesity have coincided with declines in active transportation to school. This research builds on largely atheoretical extant literature examining factors that influence walk-to-school behavior through application of the theory of planned behavior (TPB). Understanding caregivers' decision for their child to walk to/from school is key to developing interventions to promote this cost-effective and accessible health behavior. The results from an online survey of 512 caregivers provide support for the TPB, highlighting the important role of subjective norms. This suggests marketers should nurture caregivers' perception that important others approve of walking to school.

A systematic literature review of alcohol education programmes in middle and high school settings (2000-2014)

Purpose

– Social marketing benchmark criteria were used to understand the extent to which single-substance alcohol education programmes targeting adolescents in middle and high school settings sought to change behaviour, utilised theory, included audience research and applied the market segmentation process. The paper aims to discuss these issues.

Design/methodology/approach

– A systematic literature review retrieved a total of 1,495 identified articles; 565 duplicates were removed. The remaining 930 articles were then screened. Articles detailing formative research or programmes targeting multiple substances, parents, families and/or communities, as well as elementary schools and universities were excluded. A total of 31 articles, encompassing 16 qualifying programmes, were selected for detailed evaluation.

Findings

– The majority of alcohol education programmes were developed on the basis of theory and achieved short- and medium-term behavioural effects. Importantly, most programmes were universal and did not apply the full market segmentation process. Limited audience research in the form of student involvement in programme design was identified.

Research limitations/implications

– This systematic literature review focused on single-substance alcohol education programmes targeted at middle and high school student populations, retrieving studies back to the year 2000.

Originality/value

– The results of this systematic literature review indicate that application of the social marketing benchmark criteria of market segmentation and audience research may represent an avenue for further extending alcohol education programme effectiveness in middle and high school settings.

Differential segmentation responses to an alcohol social marketing program

OBJECTIVE

This study seeks to establish whether meaningful subgroups exist within a 14-16 year old adolescent population and if these segments respond differently to the Game On: Know Alcohol (GOKA) intervention, a school-based alcohol social marketing program.

METHODOLOGY

This study is part of a larger cluster randomized controlled evaluation of the GOKA program implemented in 14 schools in 2013/2014. TwoStep cluster analysis was conducted to segment 2,114 high school adolescents (14-16 years old) on the basis of 22 demographic, behavioral, and psychographic variables. Program effects on knowledge, attitudes, behavioral intentions, social norms, alcohol expectancies, and drinking refusal self-efficacy of identified segments were subsequently examined.

RESULTS

Three segments were identified: (1) Abstainers, (2) Bingers, and (3) Moderate Drinkers. Program effects varied significantly across segments. The strongest positive change effects post-participation were observed for Bingers, while mixed effects were evident for Moderate Drinkers and Abstainers.

CONCLUSIONS

These findings provide preliminary empirical evidence supporting the application of social marketing segmentation in alcohol education programs. Development of targeted programs that meet the unique needs of each of the three identified segments will extend the social marketing footprint in alcohol education.

The influence of different peritoneal dialysis fluids on the in vitro activity of ampicillin, daptomycin, and linezolid against Enterococcus faecalis

Intraperitoneal administration of antibiotics is recommended for the treatment of peritoneal dialysis-related peritonitis. However, little data are available on a possible interference between peritoneal dialysis fluids and the activity of antimicrobial agents. Thus, the present in vitro study set out to investigate the influence of different peritoneal dialysis fluids on the antimicrobial activity of ampicillin, linezolid, and daptomycin against Enterococcus faecalis. Time-kill curves in four different peritoneal dialysis fluids were performed over 24 h with four different concentrations (1 × MIC, 4 × MIC, 8 × MIC, 30 × MIC) of each antibiotic evaluated. Cation-adjusted Mueller-Hinton broth was used as the comparator solution. All four peritoneal dialysis fluids evaluated had a bacteriostatic effect on the growth of Enterococcus faecalis. Compared to the cation-adjusted Mueller-Hinton broth comparator solution, the antimicrobial activity of all antibiotics tested was reduced. For ampicillin and linezolid, no activity was found in any peritoneal dialysis fluid, regardless of the concentration. Daptomycin demonstrated dose-dependent activity in all peritoneal dialysis fluids. Bactericidal activity was observed at the highest concentrations evaluated in Dianeal® PDG4 and Extraneal®, but not in concentrations lower than 30 × MIC and not in Nutrineal® PD4 and Physioneal® 40. The antimicrobial activity of ampicillin and linezolid is limited in peritoneal dialysis fluids in vitro. Daptomycin is highly effective in peritoneal dialysis fluids and might, thus, serve as an important treatment option in peritoneal dialysis-related peritonitis. Further studies are needed to evaluate the clinical impact of the present findings.

Comparison of gadofosveset (Vasovist(®)) with gadobenate dimeglumine (Multihance(®))-enhanced MR angiography for high-grade carotid artery stenosis

OBJECTIVE

To prove superiority of blood pool contrast agent gadofosveset over conventional contrast agent gadobenate dimeglumine for assessment of stenotic internal carotid artery (ICA).

METHODS

Eleven patients with high-grade ICA stenosis (≥75%), confirmed by duplex sonography, underwent MR angiography (MRA) with gadofosveset and gadobenate dimeglumine.

RESULTS

Agreement in stenosis grade was reached in 7 of 10 stenotic ICAs. In two ICAs, gadobenate dimeglumine led to underestimation of stenosis grade. There was a significant difference in signal intensity (pre-/post-stenotic segments), showing higher values for gadofosveset (P<0.01; P<0.05). Impression of contrast intensity with gadofosveset was better in 8 ICAs and only in 1 ICA with gadobenate dimeglumine (P<0.05).

CONCLUSION

Gadofosveset-enhanced MR angiography may be superior for assessment of high-grade ICA stenosis compared with gadobenate dimeglumine MR angiography.

A new contrast in MR mammography by means of chemical exchange saturation transfer (CEST) imaging at 3 Tesla: preliminary results

PURPOSE

To evaluate the feasibility to detect and delineate malignant breast lesions in human patients by chemical exchange saturation transfer (CEST) as an MR imaging technique without the need for contrast agent administration.

MATERIALS AND METHODS

Six female patients referred for pre-surgical staging due to histologically confirmed breast cancer were examined with MR at 3 T. The routine breast protocol included T (2w), STIR, T (1w)-DCE and contrast-enhanced T (1w) imaging with SPAIR fat suppression. For CEST imaging, a 3D RF-spoiled gradient echo (GRE) sequence with an optimized saturation pulse train was applied. To assess the diagnostic value of the technique, CEST effects observed between frequency offsets of 1.2 to 1.8 ppm from the bulk water resonance were compared to pharmacokinetic parameter maps (k (ep)) obtained by DCE-MRI.

RESULTS

In 3 of 6 patients, regions with high CEST signal intensity correlated well with tumor areas as determined by DCE-MRI. Analysis of signal intensities from ROIs in tumor, fibroglandular, adipose, and muscle tissue revealed significantly higher CEST values in tumor tissue compared to fibroglandular tissue. The detection of lesions was equally well possible with DCE-MRI and CEST-MRI. In the three other patients, the tumor regions could not be delineated based on the CEST image due to artifacts, which were most likely caused by a high content of fat tissue within the ROIs.

CONCLUSION

The results of this initial feasibility study indicate a significant potential of CEST-MRI to discriminate cancer from fibroglandular tissue in the human breast by a CEST contrast generated by endogenous solute molecules.

[Normal aging and imaging correlations]

Age-related structural, functional and biochemical changes of the brain can be visualized by neuroimaging methods. Physiological aging of the brain has to be clearly distinguished from pathological alterations of the brain for reliable and early diagnoses of neurodegenerative diseases. Concerning the speed of the cerebral aging process, significant inter-individual differences can be observed. In general, aging is associated with a decline of cognitive functions. Simultaneously, a decay of the average brain volume, especially in the frontal lobe accompanies the process of aging. Correspondingly, a strong susceptibility for age-related degeneration has been observed in the fronto-striato-thalamic network. Due to increasing age the white matter is affected by a progressive loss of fiber integrity mirrored in a significant decay of the fractionated anisotropy (FA) measured by diffusion tensor imaging (DTI). Age-related degeneration of the white matter further leads to a growing number of T2 hyperintense white-matter lesions. Aging also influences the cerebral perfusion pattern leading to a perceptible decay of the global cerebral blood flow (CBF) and blood volume (CBV). During life, iron accumulates in the brain, predominantly in the globus pallidus and in the substantia nigra. By 1H-MR spectroscopy, a decrease of N-acetyl-aspartate (NAA) as a correlate for reduced neuronal metabolism is found in the brain of elderly individuals.

[MR spectroscopy in dementia]

With an increasingly aging population we are faced with the problem of an increasing number of dementia patients. In addition to clinical, neuropsychological and laboratory procedures, MRI plays an important role in the early diagnosis of dementia. In addition to various morphological changes functional changes can also help in the diagnosis and differential diagnosis of dementia. Overall the diagnosis of dementia can be improved by using parameters from MR spectroscopy. This article focuses on MR spectroscopic changes in the physiological aging process as well as on changes in mild cognitive impairment a precursor of Alzheimer's dementia, in Alzheimer's dementia, frontotemporal dementia, vascular dementia and Lewy body dementia.

Preliminary studies on Campomanesia xanthocarpa (Berg.) and Cuphea carthagenensis (Jacq.) J.F. Macbr. aqueous extract: weight control and biochemical parameters

An infusion of Campomanesia xanthocarpa Berg. (Myrtaceae) leaves (Guabiroba) and the herb Cuphea carthagenensis (Jacq.) J.F. Macbr. (Lythraceae) (Sete-sangrias) is traditionally used in the South of Brazil to treat high levels of cholesterol and triglycerides. The effects of the aqueous extracts of these herbs were investigated in rats fed on a high calorie diet. Chronic treatment with the Guabiroba aqueous extract induced a significant reduction in weight gain in the rats, compared to the control group. Also, biochemical analysis showed that this treatment reduced the glycemia, while no effects on lipidic levels were observed. The biochemical analysis of the animals treated with Sete-sangrias aqueous extract showed no effect on glucose and triglyceride levels, while chronic treatment with the Sete-sangrias aqueous extract induced a significant reduction in plasma cholesterol in rats.

[Custom-made knee endoprosthetics using subtraction data of 3-dimensional CT scans. A new approach]

A new method is presented which allows the construction and implantation of highly precise custom-made endoprostheses for knee joints. The procedure is based on a computer-aided subtraction process of three-dimensional CT data. Using the differences of the CT scans, the endprosthetic components are modelled by means of a newly developed software package. The implants are manufactured by CNC machines and stereolithography. The method enables the surgeon to reduce bone resections and ensures an exact profile of the bone-implant interface. Incorrect positioning will be avoided and the implantation process can be performed more easily while the size of the operative approach will be minimized. Better postoperative kinematics and reduction of shearing effects will lead to better results in the long run. The procedure offers a series of new possibilities to optimize monocondylar and bicondylar knee joint endoprostheses.

Hypertonic saline resuscitation of head injury: effects on cerebral water content

Ideal resuscitation would simultaneously replete intravascular volume and minimize cerebral edema. We assessed the effects of hypertonic saline (HS) shock resuscitation on cerebral edema after head injury. Rats were subjected to hemorrhagic shock (40 mm Hg for 1 hour) in the presence or absence of mechanical brain injury, followed by 1 hour of resuscitation with either hypertonic saline (6.5%) or lactated Ringer's (LR). After resuscitation, animals were sacrificed and brain water contents determined.

RESULTS

Less HS than LR was needed for resuscitation both in animals without brain injury (7 +/- 2 ml/kg vs. 97 +/- 16 ml/kg; p less than 0.0003) and with brain injury (10 +/- 1 ml/kg vs. 68 +/- 6 ml/kg; p less than 0.0001). Brain water content (ml H2O/gm dry wt) after HS resuscitation was decreased compared to LR resuscitation in animals without brain injury (3.36 +/- 0.12 vs. 3.74 +/- 0.08; p less than 0.025) and in the uninjured hemisphere of head-injured animals (3.29 +/- 0.11 vs. 3.78 +/- 0.09; p less than 0.025). Brain water content was increased in injured brain in both resuscitation groups, but the increase was the same (HS 4.10 +/- 0.13; LR 4.25 +/- 0.17; p greater than 0.05).

CONCLUSIONS

HS resuscitation of hemorrhagic shock decreases brain water content in uninjured but not injured brain. HS may be useful in resuscitation of combined hemorrhagic shock and head injury.

[Idiopathic talus necrosis in an infant]

A case of a spontaneous osteonecrosis of the talus in a 22 months old girl is reported. Under treatment in a non-weight-bearing leg brace the talus recovered without remaining deformities. Osteomyelitis, tumors, neurogenic arthropathy and traumatic origin were taken into diagnostic consideration, but could be excluded by clinical, radiological and laboratory examinations. According to our knowledge an idiopathic osteonecrosis of the talus occurring in an infant of 22 months has never been reported before.

Improved procedure for the isolation of a double-strand-specific ribonuclease and its application to structural analysis of various 5S rRNAs and tRNAs

An improved method for the isolation of a double-strand-specific RNase from snake venom is presented. This RNase, called CSV, was used to cleave yeast tRNAPhe and tRNA2Glu and tRNAfMet from Escherichia coli. In addition these RNAs and E. coli tRNAPhe were examined with the single-strand-specific nuclease S1. The results are discussed in terms of the specificity of CSV RNase and the structure of tRNAs. S1 nuclease digestions at increasing temperatures allowed the melting of tertiary and secondary structure to be monitored. 5S rRNA from E. coli, Thermoplasma acidophilum and the chloroplasts of Spinacia oleracea were digested with CSV and S1. The information these results give on the secondary-structural differences between different classes of 5S rRNA are discussed. Supporting evidence is found for tertiary interactions between hairpin loop c and internal loop d of eubacterial 5S rRNA.

The acoustic reflectometer as a screening device: a comparison

Sixty children (120 ears) were evaluated using reflectometry, pure tones, immittance, otologic examination, and pure-tone air and bone conduction thresholds. Comparisons were made between the various screeners. Reflectometry was found to be the least sensitive and the least specific of the procedures. Results were then examined within each diagnostic category to determine test agreement with the otologists' judgments. The reflectometer categorization was found to be inconsistent with the otologic findings. Finally, the reflectometer was compared to each of the other screener results and pure-tone thresholds. The test results were significantly correlated but showed high over- and under-referral rates for the reflectometer. Seventy-eight children and adults (156 ears) were screened in a second study. Again, the acoustic reflectometer did not perform adequately as a general screening tool. When only cases of middle ear effusion were screened, the acoustic reflectometer did not perform as well as immitance.

A topographic map of sensory cell terminal arborizations in the cricket CNS; correlation with birthday and position in a sensory array

The development of a group of club-shaped sensilla called clavate hairs, located on the cerci of the cricket (Acheta domesticus), was examined morphologically. The clavate hairs are located on the base of the cercus and are thought to inform the animal of its orientation with respect to gravity. There are two groups of clavate hairs distinguished from one another by the orientation of their sockets: a dorso-medial group whose sockets are oriented perpendicular to the long axis of the cercus and a ventro-medial group inclined 45-60 degrees away from the perpendicular. The ventro-medial group consists of a series of rows of sensilla running parallel to the long axis of the cercus. By examining a cast-off exoskeleton in the scanning electron microscope and comparing it with newly developed cuticle of the subsequent instar (Fig. 3), we showed how receptors were added to the ventro-medial array of clavate hairs. The first ventral hair (#10,Fig.1) appeared in the second instar. Three more hairs were added in the third instar: two (#11 and #12) proximal to hair 10 forming the first row and one (#20) medial to 11 and initiating the second row. After the third instar on hair was usually added proximal to each row each time the specimen molted. Because of the regular positioning of hairs and their orderly addition to the array, it is possible to identify uniquely all of the hairs in the three largest rows of ventral hairs (Fig. 4). We developed a simple method for staining the neuron associated with each hair. A hair was injured by cutting off its tipe. A bubble of cobaltous acetate was then placed on the hair for 18-20 hours and only the neuron associated with the injured hair took up the stain. The synaptic terminal aborizations of identified neurons examined in this manner were unique and reproducible from specimen to specimen (Fig.6). Furthermore, there is a topographic order to the terminal aborizations. Within one row the oldest neurons project furthest into the nervous system and arborize over the greatest area, whereas younger neurons aborize in more restricted areas nwer the entrance of the cercal nerve. Thus it was concluded that birthday was correlated with the morphology of the synaptic aborization. By staining neurons that were the same age but located in different rows, we determined that birthday was not the only variable influencing the morphology of the terminal arbors. The terminal arbors of neurons 11 and 20, both of which first appear in the third instar, were very different from one another. Thus another variable, presumably position on the body surface, was also correlated with the morphology of a neuron's terminal arborization. We concluded from these results that position on the cercus as well as birthday is encoded in the devlopmental program of these neurons and that the morphology of their terminal arborizations is a joint junction of these two variables.