Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Atrial fibrillation diagnosis by a systematic 14-day continuous ECG-Holter in patients with high cardiovascular risk and clinical palpitation: the prospective AFTER study

Background

Atrial Fibrillation (AF) is asymptomatic in 20–30% of cases. New technologic tools for continuous ECG monitoring have been developed to detect and potentially treat AF in specific population with high cardiovascular risk.

Purpose

We aimed to evaluate the prevalence and the management of AF diagnosed in patients with no previous documented AF but with a high cardiovascular risk and clinical palpitation undergoing systematic 14-day continuous ECG-Holter monitoring and associated characteristics.

Methods

Patients were prospectively enrolled from December 2019 to December 2021 in this multicentered study, sponsored by the French National College of Cardiology. Patients needed to meet the following criteria: CHA2DS2VASc score ≥3 in women &gt;2 in men associated with clinical palpitation without previous documented arrhythmia, particularly AF. Exclusion criteria were: previous documented AF, participation to another study that could interfere with the current study, pregnancy, previous skin intolerance to ECG-Holter electrodes. Included patients underwent a 14-day monitoring Holter-ECG to detect cardiac arrhythmia, particularly AF. Patients' characteristics, type of arrythmias and management of detected AF were described.

Results

Among the 336 included patients, 39% were men, median age was 73 [64.5–78] years, 71.5% had hypertension and 46.5% had a previous history of stroke. AF was detected in 14% of patients, among which 23.4% in the first 24 hours monitoring. In univariate analyses, older age (p=0.045) was significantly associated with AF, and a trend was observed regarding male gender (p=0.067) and less antiplatelet therapy (p=0.058). Patients with diagnosed AF had a prescription of anticoagulation therapy in 90% of cases consisting in apixaban and rivaroxaban for 72% and 28% respectively. Antiarrhythmic drugs were administered in 90% of AF patients and 13% underwent AF ablation.

Conclusions

The systematic AF screening of selected patients based on CHA2DS2VASc score ≥3 in women &gt;2 in men associated with palpitations allows to diagnose AF in 14% of the population with a 14-day continuous ECG-Holter. This strategy seems efficient as it induced the prescription of anticoagulation and antiarrhythmic therapy in 90% of individuals.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): NATIONAL COLLEGE OF FRENCH CARDIOLOGISTS

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Atlas of MRI findings of sacroiliitis in pediatric sacroiliac joints to accompany the updated preliminary OMERACT pediatric JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system: Part I: Active lesions

Magnetic resonance imaging (MRI) is an increasingly important tool for identifying involvement of the sacroiliac joints (SIJ) in juvenile idiopathic arthritis (JIA). The key feature for diagnosing active sacroiliitis is bone marrow edema (BME), but other features of active arthritis such as joint space inflammation, inflammation in an erosion cavity, capsulitis and enthesitis can be seen as well. Structural changes may also be seen. Systematic MRI assessment of inflammation and structural damage may aid in monitoring the disease course, choice of therapeutics and evaluating treatment response. In this pictorial essay, we illustrate normal MRI findings and growth-related changes of the SIJ in the pediatric population, as well as the different MRI features of SIJ inflammation. This atlas demonstrates fundamental MRI disease features of active inflammation in a format that can serve as a reference for assessing SIJ arthritis according to the updated preliminary JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system proposed by the MRI in JIA working group of Outcome Measures in Rheumatology and Clinical Trials (OMERACT). The atlas is intended to be read in conjunction with its companion Part 2, Structural Lesions.

POS1323 SACROILIAC JOINT MRI ABNORMALITIES IN JUVENILE SPONDYLOARTHRITIS: AN UPDATE OF DEFINITIONS AND SCORING OF THE OMERACT JUVENILE IDIOPATHIC ARTHRITIS MRI SCORE

Background:

Preliminary definitions for SIJ lesions in the OMERACT Juvenile Idiopathic Arthritis Magnetic Resonance Imaging score has been reported1. Investigators identified the need to revise the JAMRIS-SIJ item definitions.

Objectives:

To update the JAMRIS-SIJ definitions and scoring method.

Methods:

The OMERACT JAMRI working group was convened to discuss the performance of the score in a reliability exercise using 30 patients. Twenty investigators (12 radiologists, 8 rheumatologists) decided which definitions and scoring methods to be revised, retained or added.

Results:

The revised JAMRI-SIJ is in the Table 1.

Table 1.

Revised OMERACT JAMRIS-SIJ.

ComponentDefinitionSegmentation/sliceScore range/sliceBone Marrow Edema (BME)An ill-defined area of high bone marrow signal intensity within the subchondral bone in the ilium or sacrum on fluid sensitive images4 quadrants/SIJ0-8BME IntensityPresence of hyperintensity of the marrow on fluid sensitive images using the signal of the presacral veins or cerebrospinal fluid as reference1 score/SIJ0-2BME DepthContinuing increased signal on fluid sensitive images of depth ≥ 5mm/ ≥ 1cm from the articular surface using the signal of the presacral veins or cerebrospinal fluid as reference1 score/SIJ0-2OsteitisAn ill-defined area of high bone marrow signal intensity within the subchondral bone in the ilium or sacrum on contrast enhanced T1 weighted sequences4 quadrants/SIJ0-8CapsulitisIncreased signal on fluid sensitive or contrast enhanced T1 weighted sequences involving the superior portion of the SIJ capsulesuperior halves/SIJ0-2Joint space fluidHigh signal intensity equivalent to the CSF on fluid sensitive sequences within the joint space of the cartilaginous portion of the SIJhalves/SIJ0-4Joint space enhancementIncreased signal intensity on contrast enhanced T1 weighted sequences within the joint space of the cartilaginous portion of the SIJhalves/SIJ0-4Inflammation in erosion cavityIncreased signal intensity on fluid sensitive or contrast enhanced T1 weighted sequences in an erosion cavity of the cartilaginous portion of the SIJhalves/SIJ0-4EnthesitisIncreased signal intensity in bone marrow and/or adjacent soft tissue on fluid sensitive or contrast enhanced T1 weighted sequences at sites where ligaments and tendons attach to a bone excluding retroarticular enthesitisScore per case0-1Damage DomainSclerosisA substantially wider than normal area of very low bone marrow signal intensity within the subchondral bone in the ilium or sacrum on a non-fat suppressed sequence, preferably a non-fat suppressed T1 weighted sequence. This feature must also be present on all other sequences, as available4 quadrants/SIJ0-8ErosionA focal loss of the low signal of cortical bone at the osteochondral interface and adjacent marrow matrix on T1 weighted images4 quadrants/SIJ0-8Fat metaplasia lesionHomogeneous increased signal intensity within the subchondral bone marrow on T1weighted images4 quadrants/SIJ0-8BackfillA high signal on non-contrast enhanced T1 weighted sequences in a typical location for an erosion, with signal intensity greater than normal bone marrow, clearly demarcated from adjacent bone marrow by an irregular band of low signal reflecting sclerosis at the border of the original erosionhalves/SIJ0-4AnkylosisPresence of signal equivalent to regional bone marrow continuously bridging a portion of the joint space between the iliac and sacral boneshalves/SIJ0-4

Statement of overarching consideration for all definitions: “[…] in comparison to physiological changes normally seen on MRI examinations of age- and sex-matched children, and visible in 2 planes wherever available.”

Conclusion:

Revised JAMRIS-SIJ has been developed. Validation steps are underway.

References:

[1]Otobo TM, et al. Preliminary Definitions for Sacroiliac Joint Pathologies in the OMERACT Juvenile Idiopathic Arthritis Magnetic Resonance Imaging Score (OMERACT JAMRIS-SIJ). The Journal of rheumatology. 2019;46(9):1192-7.

Acknowledgements:

The authors acknowledge The Hospital for SickKids Research Trainee Competition (RESTRACOMP) and Queen Elizabeth II/Edward Dunlop Foundation Scholarship In Science and Technology (QEII-GSST) at the University of Toronto for funding provided to Dr. Tarimobo M. Otobo. The authors also acknowledge Prof. Dr. Desiree van der Heijde for providing expert commentary.

Disclosure of Interests:

None declared

Subradiance with Saturated Atoms: Population Enhancement of the Long-Lived States

Dipole-dipole interactions are at the origin of long-lived collective atomic states, often called subradiant, which are explored for their potential use in novel photonic devices or in quantum protocols. Here, we study subradiance beyond the single-excitation regime and experimentally demonstrate a 200-fold increase in the population of these modes, as the saturation parameter of the driving field is increased. We attribute this enhancement to a mechanism similar to optical pumping through the well-coupled superradiant states. The lifetimes are unaffected by the pump strength, as the system is ultimately driven toward the single-excitation sector. Our study is a new step in the exploration of the many-body dynamics of large open systems.

Improving pulmonary vein isolation during cryoballoon ablation using the re-look angiography technique

Background

Cryoballoon ablation for pulmonary vein (PV) antral isolation is contact-dependent. Currently, occlusion assessment using the cryoballoon is most commonly performed using contrast venogram prior to ablation. However, there is a known difference in balloon size/shape between the inflated and ablation state, due to significant increase in cryoballoon pressure, which can cause potential undetected leak and, thus, failure of PV isolation. This phenomenon is currently not detected using standard techniques and effectiveness of mitigation techniques have not been assessed.

Purpose

We hypothesize that repeat injection of contrast five seconds after the initiation of cryoballoon ablation can be used to assess changes in shape and confirm ongoing occlusion during ablation; the re-look angiography technique. The incidence of PVI leak and the ability for the relook angiography to remedy the leak is assessed.

Methods

A total of 125 patients (440 PVs) undergoing cryoballoon ablation (Medtronic Arctic Front Advance Balloon™) were assessed using the re-look angiography technique unless they required occlusion with a segmental approach. Fifteen patients were excluded from contrast use due to renal insufficiency.

Results

Successful single occlusion was seen in 330 (75%) PVs and the re-look angiography technique was employed in each of those events. In 180 of the 330 (55%) single PV occlusions, a new PV leak undetected during the initial PV angiogram was identified. This prompted repositioning of the balloon to achieve complete PV isolation in 85 of 180 of the PV cases, with 95 of the cases requiring additional segmental ablation to complete full PV isolation.

Conclusion

A significant amount of insufficient PV antral contact during cryo-ablation may not be detected with conventional single PV angiography and may explain inadequate PV isolation. The re-look angiography technique is a simple tool to confirm robust balloon contact and guide repositioning as well as identify the need for additional segmental ablation. Additional follow up is needed for translation to improved clinical outcomes.

Funding Acknowledgement

Type of funding source: None

Alterations of the salivary and fecal microbiome in patients with primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a chronic, progressive liver disease known for its frequent concurrence with inflammatory bowel disease. PSC can progress to cirrhosis, end-stage liver disease, hepatobiliary cancer, and/or colorectal cancer. The etiopathogenesis of PSC remains poorly understood, and, as such, pharmacotherapy has yet to be definitively established. Little is known about the salivary microbiome in PSC and PSC-IBD. This study aimed to evaluate the oral microbiome of patients with PSC, with association to these patient's fecal microbial composition.

METHODS

Saliva, fecal samples and Food Frequency Questionnaires were collected from 35 PSC patients with or without concomitant inflammatory bowel disease and 30 age- and BMI-matched healthy volunteers. 16S rRNA gene sequencing was performed using Illumina MiSeq platform.

RESULTS

The salivary microbial signature of PSC was significantly altered as compared to healthy controls, independent of concomitant IBD, and was comprised of 19 significantly altered species, of which, eight species were consistently overrepresented in both fecal and saliva of patients with PSC, including Veillonella, Scardovia and Streptococcus.

CONCLUSIONS

PSC is characterized by microbial dysbiosis in the gut and the salivary microbiome, independently from IBD. The PSC dysbiotic signature includes a reduction in autochthonous bacteria and an increased relative abundance of pathogenic bacteria, including an invasion of oral bacteria to the gut. PSC is a strong modulator of the microbial profile, in the gut and the oral microbiome. These results may lead to the development of biomarkers for screening and early diagnosis or the development of personalized medicine in PSC.

Exo-Ocean Exploration with Deep-Sea Sensor and Platform Technologies

One of Saturn's largest moons, Enceladus, possesses a vast extraterrestrial ocean (i.e., exo-ocean) that is increasingly becoming the hotspot of future research initiatives dedicated to the exploration of putative life. Here, a new bio-exploration concept design for Enceladus' exo-ocean is proposed, focusing on the potential presence of organisms across a wide range of sizes (i.e., from uni- to multicellular and animal-like), according to state-of-the-art sensor and robotic platform technologies used in terrestrial deep-sea research. In particular, we focus on combined direct and indirect life-detection capabilities, based on optoacoustic imaging and passive acoustics, as well as molecular approaches. Such biologically oriented sampling can be accompanied by concomitant geochemical and oceanographic measurements to provide data relevant to exo-ocean exploration and understanding. Finally, we describe how this multidisciplinary monitoring approach is currently enabled in terrestrial oceans through cabled (fixed) observatories and their related mobile multiparametric platforms (i.e., Autonomous Underwater and Remotely Operated Vehicles, as well as crawlers, rovers, and biomimetic robots) and how their modified design can be used for exo-ocean exploration.

Collective Multimode Vacuum Rabi Splitting

We report the experimental observation of collective multimode vacuum Rabi splitting in free space. In contrast to optical cavities, the atoms couple to a continuum of modes, and the optical thickness of the cloud provides a measure of this coupling. The splitting, also referred as normal mode splitting, is monitored through the Rabi oscillations in the scattered intensity, and the results are fully explained by a linear-dispersion theory.

Kinematic features of whole-body reaching movements underwater: Neutral buoyancy effects

Astronauts' training is conventionally performed in a pool to reproduce weightlessness by exploiting buoyancy which is supposed to reduce the impact of gravity on the body. However, this training method has not been scientifically validated yet, and requires first to study the effects of underwater exposure on motor behavior. We examined the influence of neutral buoyancy on kinematic features of whole-body reaching underwater and compared them with those produced on land. Eight professional divers were asked to perform arm reaching movements toward visual targets while standing. Targets were presented either close or far from the subjects (requiring in the latter case an additional whole-body displacement). Reaching movements were performed on land or underwater in two different contexts of buoyancy. The divers either wore a diving suit only with neutral buoyancy applied to their center of mass or were additionally equipped with a submersible simulated space suit with neutral buoyancy applied to their body limbs. Results showed that underwater exposure impacted basic movement features, especially movement speed which was reduced. However, movement kinematics also differed according to the way buoyancy was exerted on the whole-body. When neutral buoyancy was applied to the center of mass only, some focal and postural components of whole-body reaching remained close to land observations, notably when considering the relative deceleration duration of arm elevation and concomitant forward trunk bending when reaching the far target. On the contrary, when neutral buoyancy was exerted on body segments, movement kinematics were close to those reported in weightlessness, as reflected by the arm deceleration phase and the whole-body forward displacement when reaching the far target. These results suggest that astronauts could benefit from the application of neutral buoyancy across the whole-body segments to optimize underwater training and acquire specific motor skills which will be used in space.

Glycidyl alkoxysilane reactivities towards simple nucleophiles in organic media for improved molecular structure definition in hybrid materials

We report the first comprehensive study of the reactivity in organic media of (3-glycidyloxypropyl)trialkoxysilanes towards common nucleophiles. Their reactivity have to be emphasized in order to design and to improve new sol–gel hybrid synthesis.

Vascular imaging with contrast agent in hard and soft tissues using microcomputed-tomography

Vascularization is essential for many tissues and is a main requisite for various tissue-engineering strategies. Different techniques are used for highlighting vasculature, in vivo and ex vivo, in 2-D or 3-D including histological staining, immunohistochemistry, radiography, angiography, microscopy, computed tomography (CT) or micro-CT, both stand-alone and synchrotron system. Vascularization can be studied with or without a contrast agent. This paper presents the results obtained with the latest Skyscan micro-CT (Skyscan 1272, Bruker, Belgium) following barium sulphate injection replacing the bloodstream in comparison with results obtained with a Skyscan In Vivo 1076. Different hard and soft tissues were perfused with contrast agent and were harvested. Samples were analysed using both forms of micro-CT, and improved results were shown using this new micro-CT. This study highlights the vasculature using micro-CT methods. The results obtained with the Skyscan 1272 are clearly defined compared to results obtained with Skyscan 1076. In particular, this instrument highlights the high number of small vessels, which were not seen before at lower resolution. This new micro-CT opens broader possibilities in detection and characterization of the 3-D vascular tree to assess vascular tissue engineering strategies.

[Mental changes in women due to the use of hormonal contraception]

The study investigates physical, mental and sexual changes in women at the beginning of use or after discontinuation of a combined hormonal contraception. Thirty women were interviewed at least 3 months and at most 2 years after the start of use or discontinuation of combined hormonal contraception. Semi-structured interviews were supplemented by 16-symptom rating scale on which women assessed the results of an imaginary study of side effects of hormonal contraception. Both methods identically demonstrated pronounced effect of combined hormonal contraception on decline in sexual desire and painful menstruation. No clear difference was found in psychical symptoms, although qualitative analysis indicated possible changes.

Direct comparison of current cell-based and cell-free approaches towards the repair of craniofacial bone defects - A preclinical study

For craniofacial bone defect repair, several alternatives to bone graft (BG) exist, including the combination of biphasic calcium phosphate (BCP) biomaterials with total bone marrow (TBM) and bone marrow-derived mesenchymal stromal cells (MSCs), or the use of growth factors like recombinant human bone morphogenic protein-2 (RhBMP-2) and various scaffolds. Therefore, clinicians might be unsure as to which approach will offer their patients the most benefit. Here, we aimed to compare different clinically relevant bone tissue engineering methods in an "all-in-one" study in rat calvarial defects. TBM, and MSCs committed or not, and cultured in two- or three-dimensions were mixed with BCP and implanted in bilateral parietal bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant de novo bone formation was observed in rhBMP-2 and BG groups, and in a lesser amount, when BCP biomaterials were mixed with TBM or committed MSCs cultured in three-dimensions. Due to the efficacy and safety of the TBM/BCP combination approach, we recommend this one-step procedure for further clinical investigation.

STATEMENT OF SIGNIFICANCE

For craniofacial repair, total bone marrow (BM) and BM mesenchymal stem cell (MSC)-based regenerative medicine have shown to be promising in alternative to bone grafting (BG). Therefore, clinicians might be unsure as to which approach will offer the most benefit. Here, BM and MSCs committed or not were mixed with calcium phosphate ceramics (CaP) and implanted in bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant bone formation was observed in rhBMP-2 and BG groups, and when CaP were mixed with BM or committed MSCs. Since the BM-based procedure does not require bone harvest or cell culture, but provides de novo bone formation, we recommend consideration of this strategy for craniofacial applications.

Production of hyperpolarized H_{2} molecules from H[over →] atoms in gas-storage cells

The preservation of the nuclear polarization of hydrogen atoms during the recombination to molecules was observed on different surface materials in the temperature range from 45 to 100 K and for magnetic fields up to 1 T. On a gold and a fused quartz surface, the expected molecular polarization of about 50% or lower of the atomic polarization was measured, while a surface layer of perfluoropolyether (Fomblin) shows a nearly complete preservation (at least 97%) of the atomic polarization during the recombination process. Further experiments have the possibility of storing polarized deuterium molecules and to use them in nuclear-fusion installations. Another application might be the production of polarized substances for enhanced NMR techniques.

Enriching a cellulose hydrogel with a biologically active marine exopolysaccharide for cell-based cartilage engineering

The development of biologically and mechanically competent hydrogels is a prerequisite in cartilage engineering. We recently demonstrated that a marine exopolysaccharide, GY785, stimulates the in vitro chondrogenesis of adipose stromal cells. In the present study, we thus hypothesized that enriching our silated hydroxypropyl methylcellulose hydrogel (Si-HPMC) with GY785 might offer new prospects in the development of scaffolds for cartilage regeneration. The interaction properties of GY785 with growth factors was tested by surface plasmon resonance (SPR). The biocompatibility of Si-HPMC/GY785 towards rabbit articular chondrocytes (RACs) and its ability to maintain and recover a chondrocytic phenotype were then evaluated in vitro by MTS assay, cell counting and qRT-PCR. Finally, we evaluated the potential of Si-HPMC/GY785 associated with RACs to form cartilaginous tissue in vivo by transplantation into the subcutis of nude mice for 3 weeks. Our SPR data indicated that GY785 was able to physically interact with BMP-2 and TGFβ. Our analyses also showed that three-dimensionally (3D)-cultured RACs into Si-HPMC/GY785 strongly expressed type II collagen (COL2) and aggrecan transcripts when compared to Si-HPMC alone. In addition, RACs also produced large amounts of extracellular matrix (ECM) containing glycosaminoglycans (GAG) and COL2. When dedifferentiated RACs were replaced in 3D in Si-HPMC/GY785, the expressions of COL2 and aggrecan transcripts were recovered and that of type I collagen decreased. Immunohistological analyses of Si-HPMC/GY785 constructs transplanted into nude mice revealed the production of a cartilage-like extracellular matrix (ECM) containing high amounts of GAG and COL2. These results indicate that GY785-enriched Si-HPMC appears to be a promising hydrogel for cartilage tissue engineering. Copyright © 2015 John Wiley & Sons, Ltd.

Sensitivity of ultracold atoms to quantized flux in a superconducting ring

We report on the magnetic trapping of an ultracold ensemble of (87)Rb atoms close to a superconducting ring prepared in different states of quantized magnetic flux. The niobium ring of 10  μm radius is prepared in a flux state n Φ(0), where Φ(0)=h/2e is the flux quantum and n varying between ±6. An atomic cloud of 250 nK temperature is positioned with a harmonic magnetic trapping potential at ∼18  μm distance below the ring. The inhomogeneous magnetic field of the supercurrent in the ring contributes to the magnetic trapping potential of the cloud. The induced deformation of the magnetic trap impacts the shape of the cloud, the number of trapped atoms, as well as the center-of-mass oscillation frequency of Bose-Einstein condensates. When the field applied during cooldown of the chip is varied, the change of these properties shows discrete steps that quantitatively match flux quantization.

Evaluation of new bone formation in irradiated areas using association of mesenchymal stem cells and total fresh bone marrow mixed with calcium phosphate scaffold

The consequences of the treatment of the squamous cell carcinomas of the upper aerodigestive tract (bone removal and external radiation therapy) are constant. Tissue engineering using biphasic calcium phosphate (BCP) and mesenchymal stem cells (MSC) is considered as a promising alternative. We previously demonstrated the efficacy of BCP and total fresh bone marrow (TBM) in regenerating irradiated bone defect. The aim of this study was to know if adding MSC to BCP + TBM mixture could improve the bone formation in irradiated bone defects. Twenty-four Lewis 1A rats received a single dose of 20 Gy to the hind limbs. MSC were sampled from non-irradiated donors and amplified in proliferative, and a part in osteogenic, medium. 3 weeks after, defects were created on femurs and tibias, which were filled with BCP alone, BCP + TBM, BCP + TBM + uncommitted MSC, or BCP + TBM + committed MSC. 3 weeks after, samples were removed and prepared for qualitative and quantitative analysis. The rate of bone ingrowth was significantly higher after implantation of BCP + TBM mixture. The adding of a high concentration of MSC, committed or not, didn't improve the bone regeneration. The association BCP + TBM remains the most efficient material for bone substitution in irradiated areas.

Contribución al estudio de la Bartonella Muris

1921 E. Mayer del Instituto Tropical de Hamburgo, estudiando la acción del "Bayer 0205" sobre ratas infectadas experimentalmente con tripanosoma Rhodesiense, observó la presencia de elementos en los glóbulos rojos, cuya morfología juzgó bastante semejante a la de la Bartonella bacilliformis agente etiológico de la verruga peruana.

Osteoinduction of biphasic calcium phosphate scaffolds in a nude mouse model

Bioceramics combined with isolated stem cells, or with total bone marrow, constitute the main strategies under consideration in the field of bone tissue engineering. In the present preclinical study, two biphasic calcium phosphate scaffolds currently on the market, MBCP® and MBCP+®, with different hydroxyapatite/β-tricalcium phosphate ratio, were implanted ectopically in a nude mouse model. These scaffolds were supplemented either with human mesenchymal stromal cells, or with human total bone marrow, or rat total bone marrow. Biomaterials alone were found to have potentially low, but non-zero, osteoinductive properties, while biomaterials associated with total bone marrow consistently improved osteoinduction in comparison with high concentrations of isolated human stromal cells.

On variant strategies to solve the magnitude least squares optimization problem in parallel transmission pulse design and under strict SAR and power constraints

Parallel transmission is a very promising candidate technology to mitigate the inevitable radio-frequency (RF) field inhomogeneity in magnetic resonance imaging at ultra-high field. For the first few years, pulse design utilizing this technique was expressed as a least squares problem with crude power regularizations aimed at controlling the specific absorption rate (SAR), hence the patient safety. This approach being suboptimal for many applications sensitive mostly to the magnitude of the spin excitation, and not its phase, the magnitude least squares (MLS) problem then was first formulated in 2007. Despite its importance and the availability of other powerful numerical optimization methods, the MLS problem yet has been faced almost exclusively by the pulse designer with the so-called variable exchange method. In this paper, we investigate various two-stage strategies consisting of different initializations and nonlinear programming approaches, and incorporate directly the strict SAR and hardware constraints. Several schemes such as sequential quadratic programming, interior point methods, semidefinite programming and magnitude squared least squares relaxations are studied both in the small and large tip angle regimes with RF and static field maps obtained in vivo on a human brain at 7T. Convergence and robustness of the different approaches are analyzed, and recommendations to tackle this specific problem are finally given. Small tip angle and inversion pulses are returned in a few seconds and in under a minute respectively while respecting the constraints, allowing the use of the proposed approach in routine.

Effect of water velocity on hydroponic phytoremediation of metals

The influence of flow velocity on the uptake of cadmium, copper, lead, and zinc by hydroponically grown soft stem bulrush (Scirpus validus) was investigated. The roots of the plants were exposed to a continually recycled, nutrient enriched, synthetic stormwater. Plants were divided into groups and the roots of each group exposed to different but constant water velocities. The metal concentrations in the roots and stems were compared after three weeks. Metal accumulation in roots was increased for water velocities between 1.3 and 4.0 cm s(-1). In a second experiment, the roots of all plants were exposed to a single velocity and the root and stem metal concentrations were determined as a function of time. Metal concentrations in the roots approached a constant value after three weeks. After this time, accumulation of metals depends upon root growth. The results suggest that long-term accumulation by the roots of hydroponic Scirpus validus can be increased by increasing water velocity, which implies that floating islands with movement will retain more metals from the water column.

[First manifestation of a leucocytoclastic vasculitis in the colon: case report and differential diagnostic aspects]

This report presents a female patient suffering from chronic diarrhea, who developed palpable purpura on the lower extremities 8 weeks after onset of the gastrointestinal symptoms. Biopsies obtained from the colon and skin showed leukocytoclastic vasculitis. Possible triggers or underlying diseases could not be found, and the patient recovered without specific treatment for vasculitis. Possible differential diagnoses and the difficulties in classifying vasculitides are discussed in the present report.

Parkinsonian arm movements as altered by task difficulty

A discrete elbow movement to targets with different indexes of difficulty (ID) was used to determine the kinematic organization of arm movements in a young, an elderly and a Parkinson's disease (PD) group (n = 14). Target size and movement amplitude changes led to expected modifications of the kinematics in all three groups according to Fitts' law. Increased task demands by changing target size produced not only differences between the age-groups, but affected the modulation of velocity and acceleration in the parkinsonian patients differentially. For large amplitude movements, the PD patients were less able to increase velocity and acceleration magnitudes when target accuracy constraints were reduced. These findings, when taken together with the observation that speed scaling was preserved for small movement amplitudes, suggest that a reduced capability to initiate and regulate force is the cause for the observed slowness in PD.

[Pneumatosis intestinalis in anorexia nervosa: a case report]

Pneumatosis intestinalis (PI) is identified as the accumulation of gas within the wall of the small or large intestine. It was first described by Du Vernoi in 1783. The pathogenesis is supposed to be multifactorial. It is assumed that there are 3 paths of disease development: mechanical, bacterial and biochemical. Adult patients are mostly asymptomatic and PI is diagnosed frequently by different radiological methods. The treatment of patients depends on their clinical picture. Most patients can be treated only with antibiotics and elemental diet. In a small number of cases, surgical intervention is essential. We report about a 35-year-old female patient with anorexia nervosa who developed PI after an excessive use of chewing gum for 3 years.

Alternating direction method of multipliers applied to 3D light sheet fluorescence microscopy image deblurring using GPU hardware

This paper focuses on the deblurring and denoising of Poisson noise contaminated images acquired with a new imaging technique producing large 3D data sets: Light Sheet Fluorescence Microscopy. This paper details the optimization algorithm used, which is based on the Alternating Direction Method of Multipliers, and its efficient implementation using GPU hardware. In practice, a 3D 100 million voxel image is deconvolved in five minutes, which is at least 25 times faster than a state-of-the-art MATLAB implementation.

[Synthetic calcium phosphate ceramics in secondary alveoloplasty]

INTRODUCTION

Bone substitutes are rarely used in the reconstruction of cleft lip and palate. The graft material of choice is cancellous bone, harvested in the hip or tibia. Tibial harvesting may lead to postoperative morbidity, or even complications. This has lead surgeons to develop alternative solution. We present a secondary alveolar bone grafting technique using synthetic calcium phosphate ceramics.

OBSERVATION

A patient presenting with a complete unilateral cleft lip and palate was treated by alveolar bone grafting at the age of nine years, using a mixture of autologous bone, harvested on the operative field, and particles of biphasic calcium phosphate (BCP); the graft was included in a platelet rich plasma (PRP) gel. The patient was followed up for eight years after the procedure. No sign of early or late infection was observed. At the end of facial growth, the cuspid had erupted correctly in a safe periodontal environment. Sequential X-rays showed complete filling of the initial bone defect, progressive resorption of ceramics, and spontaneous eruption of the cuspid.

DISCUSSION

In this long-term follow-up report, the use of BCP mixed with autologous bone did not interfere with dental eruption or maxilla growth. A second bone-harvesting site was thus avoided. BCP could be a suitable alternative to autologous bone graft for secondary alveoloplasty.

An in vitro study of two GAG-like marine polysaccharides incorporated into injectable hydrogels for bone and cartilage tissue engineering

Natural polysaccharides are attractive compounds with which to build scaffolds for bone and cartilage tissue engineering. Here we tested two non-standard ones, HE800 and GY785, for the two-dimensional (2-D) and three-dimensional (3-D) culture of osteoblasts (MC3T3-E1) and chondrocytes (C28/I2). These two glycosaminoglycan-like marine exopolysaccharides were incorporated into an injectable silylated hydroxypropylmethylcellulose-based hydrogel (Si-HPMC) that has already shown its suitability for bone and cartilage tissue engineering. Results showed that, similarly to hyaluronic acid (HA) (the control), HE800 and GY785 significantly improved the mechanical properties of the Si-HPMC hydrogel and induced the attachment of MC3T3-E1 and C28/I2 cells when these were cultured on top of the scaffolds. Si-HPMC hydrogel containing 0.67% HE800 exhibited the highest compressive modulus (11kPa) and allowed the best cell dispersion, especially of MC3T3-E1 cells. However, these cells did not survive when cultured in 3-D within hydrogels containing HE800, in contrast to C28/I2 cells. The latter proliferated in the microenvironment or concentrically depending on the nature of the hydrogel. Among all the constructs tested the Si-HPMC hydrogels containing 0.34% HE800 or 0.67% GY785 or 0.67% HA presented the most interesting features for cartilage tissue engineering applications, since they offered the highest compressive modulus (9.5-11kPa) while supporting the proliferation of chondrocytes.

Phosphate-dependent stimulation of MGP and OPN expression in osteoblasts via the ERK1/2 pathway is modulated by calcium

Inorganic phosphate (Pi) acts as a signaling molecule in bone-forming cells, affecting cell functions and gene expression. Particularly, Pi stimulates the expression of mineralization-associated genes such as matrix gla protein (MGP) and osteopontin (OPN) through the ERK1/2 pathway. With respect to the presence of elevated extracellular calcium and Pi levels during bone remodeling, we questioned whether calcium might play a role in the Pi-dependent effects in osteoblasts. We first showed by Western blot and real-time PCR that the concomitant presence of 10 mM Pi and 1.8 mM calcium is required to stimulate ERK1/2 phosphorylation and MGP/OPN genes expression. The mechanisms involved in the cellular effects of calcium in the presence of Pi were subsequently examined. Firstly, the use of the calcium-sensing receptor (CaSR) agonist gadolinium and the G-protein inhibitor pertussis toxin enabled us to determine that a CaSR mechanism is not involved in the Pi and calcium mediated cellular effects. By transmission electron microscopy, we next demonstrated that adding 10mM Pi to the culture medium containing 1.8mM calcium led to the formation calcium phosphate precipitates (CaPp). Moreover, treatment of osteoblasts with exogenous pre-synthesized CaPp stimulated ERK1/2 phosphorylation and MGP/OPN genes expression. In spite of high extracellular calcium and Pi concentrations, this stimulation was blunted in the presence of phosphocitrate, an inhibitor of crystal formation. Finally, we showed that despite that CaPp are not endocytosed, their effect on ERK1/2 phosphorylation and MGP/OPN genes expression were dependent on lipid rafts integrity. In summary, we showed that calcium is required for Pi-dependent ERK1/2 phosphorylation and regulation of mineralization-associated genes in osteoblasts and that its effect could originate from extracellular-related effects of CaPp that are dependent on the integrity of lipid rafts.

Inorganic phosphate stimulates apoptosis in murine MO6-G3 odontoblast-like cells

OBJECTIVE

Dental pathologies such as caries are the most prevalent disease worldwide with infectious and social complications. During the process of caries formation, the tooth is degraded and demineralization of enamel and dentine leads to the release of large amounts of inorganic phosphate (Pi) within dental tubuli. As Pi has been shown to induce apoptosis in skeletal cells, including osteoblasts and chondrocytes, we questioned whether high concentrations of Pi could affect odontoblast viability, proliferation and apoptosis.

DESIGN

Using the odontoblast-like MO6-G3 cell line as a model, we used cell counting and MTS-based colorimetric assays to measure cell viability and proliferation. Apoptosis was assessed using Hoechst nuclei staining and detection of the early apoptotic markers annexin V and Apo2.7.

RESULTS

We show for the first time that a high Pi concentration (7 mM) induced a decrease in odontoblast viability and proliferation together with a large increase in apoptosis. These effects were blunted in calcium-free medium, possibly due to the formation of calcium-phosphate crystals in the presence of high Pi concentrations.

CONCLUSION

This study contributes to clarifying the effect of Pi on odontoblast viability and apoptosis, which may improve our understanding of the role of Pi during caries formation.

In vitro characterisation of calcium phosphate biomaterials loaded with lidocaine hydrochloride and morphine hydrochloride

Calcium phosphate substitutes drug delivery systems are well known substances used in minor bone void-filling to release their therapeutic agent in situ. Few studies associating anaesthetics and analgesics have been performed to date. The aim of this work was to study the association of the analgesic, morphine, and the local anaesthetic, lidocaine, with a calcium deficient apatite matrix. Three types of biomaterials i.e. powders, granules and blocks, were prepared by isostatic compression, wet granulation and a combination of the two, evaluated and compared. The chemical structure of the associated therapeutic agent was studied and the characteristics of the drug delivery systems were appraised in terms of drug release. The integrity of the lidocaine hydrochloride structure, as determined by RMN (1)H, was confirmed regardless of the formulation technique used (isostatic compression or wet granulation). However, analyses of morphine hydrochloride by RMN (1)H revealed slight structural modifications. The association and formulation techniques that were used made it possible to obtain an in vitro release time varying from 1 to 4 days for lidocaine hydrochloride and from 1 to 3 days for morphine hydrochloride.