Tumor enlargement in adrenal incidentaloma is related to glaucoma: a new prognostic feature?

PURPOSE

The uncertainty on the management of small adrenal incidentalomas (AIs) still represents a challenge in real clinical practice. Considering the lack of knowledge on risk factors implicated in tumour enlargement, the aim of this study was to identify risk factors for morphological changes during follow-up of adrenal incidentalomas (AIs).

METHODS

We retrospectively evaluated demographic, clinical, radiological and biochemical parameters of 153 AIs (2007-2021). Patients with histological diagnosis of metastases or pheochromocytoma were excluded. To detect risk factors for tumor enlargement, diseases associated with AIs were included if their prevalence was higher than 2%. Patients were divided into two groups (A: radiological stability; B: tumor enlargement defined as > 5 mm/year in the main diameter).

RESULTS

Group A: 89.5% and group B: 10.5%, mean follow-up 38.6 ± 6.9 months (range 6-240). Tumor enlargement when occurred was within 36 months of follow-up. In group B high body weight (p < 0.03), dehydroepiandrosterone sulfate (DHEAS) (p < 0.05) and direct renin concentration (DRC) (p < 0.04) were higher than group A, while aldosterone levels were lower; moreover, considering comorbidities, glaucoma and dysglycemia (p < 0.01 for both) had higher prevalence in group B. Glaucoma and dysglycemia were independent predictors of enlargement. Patients affected by glaucoma, atrial fibrillation, dysglycemia had a lower dimensional change-free survival than non-affected.

CONCLUSIONS

Glaucoma might be a novel risk factor for AI enlargement. If subtle undetectable cortisol hypersecretion has a role is a topic for further research.

Effects of the Full-Body in-Bed Gym program on quality of life, pain and risk of sarcopenia in elderly sedentary individuals: preliminary positive results of a Padua prospective observational study

Age-related muscle loss poses a significant health concern in an aging population. This study aimed to assess the impact of a home Full-Body in-Bed Gym protocol on quality of life, pain and risk of sarcopenia in elderly subjects. A total of 22 subjects with a median age of 71.90 years were included in the study. Patients participating in the Full-Body in-Bed Gym program, with a frequency of three times a week for two months, demonstrated a significant enhancement in their quality of life, as indicated by the 12-Item Short Form Health Survey (SF-12) Mental Component Summary (p = 0.04), and an improvement in pain levels (p = 0.03). Although not statistically significant, there was also an improvement in sarcopenia risk. Patients were given the freedom to decide whether to continue treatment after the evaluation of outcomes. Patient compliance with the exercise protocol over six months indicated its feasibility and sustainability, even in the long term. These findings suggest that the Full-Body in-Bed Gym protocol may play a valuable role in mitigating age-related muscle loss, emphasizing the importance of further investigation into such rehabilitation and prevention strategies.

Treatments for hearing loss in osteogenesis imperfecta: a systematic review and meta-analysis on their efficacy

About 70% of people with osteogenesis imperfecta (OI) experience hearing loss. There is no cure for OI, and therapies to ameliorate hearing loss rely on conventional treatments for auditory impairments in the general population. The success rate of these treatments in the OI population with poor collagenous tissues is still unclear. Here, we conduct a systematic review and meta-analysis on the efficacy of treatments addressing hearing loss in OI. This study conforms to the reporting standards of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Data sources include published articles in Medline via PubMed, Web of Science, Scopus, and Embase, from their inception to November 2020. Studies included individuals with OI undergoing a hearing loss treatment, having pre- and postoperative objective assessment of hearing function at a specified follow-up length. Our search identified 1144 articles, of which 67 were reviewed at full-text screening. A random-effects meta-analysis was conducted on the selected articles (n = 12) of people with OI that underwent stapes surgery. Success was assessed as the proportion of ears with a postoperative Air-Bone Gap (ABG) ≤ 10 dB. A systematic review was conducted on the remaining articles (n = 13) reporting on other treatments. No meta-analysis was conducted on the latter due to the low number of articles on the topic and the nature of single case studies. The meta-analysis shows that stapes surgeries have a low success rate of 59.08 (95% CI 45.87 to 71.66) in the OI population. The systematic review revealed that cochlear implants, bone-anchored hearing aids, and other implantable hearing aids proved to be feasible, although challenging, in the OI population, with only 2 unsuccessful cases among the 16 reviewed single cases. This analysis of published data on OI shows poor clinical outcomes for the procedures addressing hearing loss. Further studies on hearing loss treatments for OI people are needed. Notably, the mechanisms of hearing loss in OI need to be determined to develop successful and possibly non-invasive treatment strategies.

Mammalian middle ear mechanics: A review

The middle ear is part of the ear in all terrestrial vertebrates. It provides an interface between two media, air and fluid. How does it work? In mammals, the middle ear is traditionally described as increasing gain due to Helmholtz’s hydraulic analogy and the lever action of the malleus-incus complex: in effect, an impedance transformer. The conical shape of the eardrum and a frequency-dependent synovial joint function for the ossicles suggest a greater complexity of function than the traditional view. Here we review acoustico-mechanical measurements of middle ear function and the development of middle ear models based on these measurements. We observe that an impedance-matching mechanism (reducing reflection) rather than an impedance transformer (providing gain) best explains experimental findings. We conclude by considering some outstanding questions about middle ear function, recognizing that we are still learning how the middle ear works.

POS0297 EFFECTIVENESS AND SAFETY OF SECUKINUMAB IN AXIAL SPONDYLOARTHRITIS: A 24-MONTH PROSPECTIVE, MULTICENTER REAL-LIFE STUDY

Background

Axial Spondyloarthritis (axSpA) can be distinguished in radiographic axSpA (r-axSpA) and non-radiographic (nr-axSpA). Secukinumab (SEC) is a novel treatment for axSpA, but data from real-life are still missing.

Objectives

To evaluate, in a multicentric-Italian-cohort of axSpA patients on SEC followed for 24-months: a)the long-term effectiveness and safety of SEC; b)the drug-retention-rate and low-disease-activity (LDA) measured as BASDAI<4/ASDAS<2.1 and very-low-disease-activity (VLDA) measured as BASDAI<2/ASDAS<1.3; c)any differences in outcomes according to: line of biological treatment (naïve/non-naïve), gender (male/female), subtype of axSpA (r-axSpA/nr-axSpA).

Methods

Consecutive patients with active axSpA (diagnosis according Assessment of SpondyloArthritis International Society ASAS criteria), who started SEC treatment, were evaluated prospectively. Data on disease characteristics, previous/ongoing treatments and imaging were collected. Disease-activity/functional/clinical scores and biochemical values were recorded at baseline (T0), at 6 (T6), 12 (T12), and 24 (T24) months. Effectiveness was evaluated over-time with descriptive statistics; multivariate Cox and logistic regression models were used to evaluate predictors of drug-discontinuation and LDA at T6. Infections, adverse events were recorded.

Results

249 patients (47.8% male; median age 51 years) were enrolled; 40.9% had HLA-B27; 53.8% had r-axSpA and 46.2% nr-axSpA. SEC was prescribed in 28.9% naïve and in 71.1% non-naïve patients. SEC effectiveness was shown as an improvement in several outcomes, such as ASDAS [T0=3.5(2.9-4.4) vs. T24=1.9(1.2-2.4);p=0.02] and BASDAI [T0=6.5(5.0-7.5) vs. T24=2.8(1.8-4.0);p=0.03]. After 24-months of treatment, 90.7% of naïve and 75.3% of non-naïve patients achieved LDA (BASDAI<4). At T24 naïve-patients showed better physical-functioning and lower disease-activity than non-naïve (Table 1). Similarly, at T24 we observed better physical functioning and lower inflammatory activity in males vs. females and in nr-axSpA vs. r-axSpA subjects. Retention-rate at T24 was 75% in the whole population, with some difference depending on gender (log-rank 9.319; p=0.002) (Figure 1). Treatment was discontinued in 61 patients (24.5%), mainly due to primary/secondary loss of effectiveness events (20 and 24 subjects, respectively), and only 17 patients (6.8%) due to adverse events (7 for reactions at the injection site or skin manifestations, 1 for gastro-intestinal complications, 1 for relapsing uveitis, 1 for hypertransaminasemia, 4 for severe recurrent infections, 3 due to the onset of new cancer).

Table 1.

Clinical, functional, disease activity and serological parameters of naïve (n=72) and non-naïve (n=177) axSpA patients during the 24-month follow-up

T0T6T12T24BASMI [0-10], median (IQR)naïve2.0 (1.0-4.0)2.0 (0.0-3.3)1.0 (0.0-2.8)1.0 (0.0-2.0)non-naïve4.0 (1.0-7.0)4.0 (1.0-7.0)2.0 (1.0-4.0)2.0 (1.0-3.0)pp=0.03p=0.04nsnsHAQ-S [0-8], median (IQR)naïve0.8 (0.5-1.3)0.5 (0.0-1.0)0.3 (0.0-1.0)0.1 (0.0-0.5)non-naïve1.1 (0.8-1.5)1.0 (0.4-1.3)0.6 (0.4-0.9)0.7 (0.1-0.9)pp=0.04p=0.04p=0.04p=0.04ASDAS [0-6], median (IQR)naïve3.3 (2.7-3.9)2.1 (1.6-2.7)2.0 (1.2-2.8)1.3 (1.0-2.2)non-naïve3.7 (2.9-4.7)2.9 (2.0-3.7)2.1 (1.9-3.1)2.3 (1.6-2.3)pnsnsnsp=0.04ESR [0-25](mm/h), median (IQR)naïve14.0 (6.0-27.0)10.0 (4.0-19.5)8.0 (3.1-12.8)5.0 (2.0-15.0)non-naïve18.5 (10.0-31.3)15.0 (8.0-25.0)12.0 (6.0-20.0)12.0 (6.0-19.0)pp=0.04p=0.04p=0.04p=0.04

Legend: BASMI: Bath Ankylosing Spondylitis Metrology Index; HAQ: Health Assessment Questionnaire modified for spondyloarthritis; ASDAS: Ankylosing Spondylitis Disease Activity Score; ESR: erythrocyte sedimentation rate

Conclusion

In a real-life clinical-setting, SEC proved to be safe and effective in axSpA, mainly in naïve-patients, with a notable drug-retention-rate. No differences were observed between r-axSpA and nr-axSpA.

Acknowledgements

Contributing authors of the Spondyloartritis and Psoriatic Arthritis SIR Study Group “Antonio Spadaro”: Alberto Cauli, MD, PhD, Rheumatology Unit, Department of Medical Sciences, AOU and University of Cagliari, Cagliari, Sardegna, Italy; Angelo Semeraro, MD, Rheumatology Unit, Martina Franca-ASL Taranto, Puglia, Italy; Leonardo Santo, MD, Rheumatology Unit, ASL BT Andria – DSS4 Barletta, Italy, Barletta-Andria-Trani, Puglia, Italy; Emanuela Praino, MD, Rheumatology Unit, ASL BT Andria – DSS4 Barletta, Italy, Barletta-Andria-Trani, Puglia, Italy; Giorgio Amato, MD, Rheumatology Unit, A.O.U. Policlinico S. Marco, Catania, Sicilia, Italy; Nicolò Girolimetto, MD, Rheumatology Unit, Department of Internal Medicine, Azienda USL-IRCCS, Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia, Emilia Romagna, Italy.

Disclosure of Interests

Giacomo Cozzi: None declared, Mariagrazia Lorenzin: None declared, Maria Sole Chimenti: None declared, Salvatore D’Angelo: None declared, Antonio Marchesoni: None declared, Carlo Salvarani: None declared, Ennio Lubrano: None declared, Luisa Costa: None declared, Ylenia Dal Bosco: None declared, Elena Fracassi: None declared, Augusta Ortolan: None declared, Mario Ferraioli: None declared, Antonio Carriero: None declared, elisa visalli: None declared, RICCARDO BIXIO: None declared, Francesca Desiati: None declared, ALBERTO BERGAMINI: None declared, elisa pedrollo: None declared, Andrea Doria Grant/research support from: Novartis, Abbvie, Pfizer, MSD, Janssen, Rosario Foti: None declared, Antonio Carletto: None declared, Roberta Ramonda Grant/research support from: Novartis, Abbvie, Pfizer, MSD, Janssen

A systematic review and meta-analysis on the efficacy of stem cell therapy on bone brittleness in mouse models of osteogenesis imperfecta

There is no cure for osteogenesis imperfecta (OI), and current treatments can only partially correct the bone phenotype. Stem cell therapy holds potential to improve bone quality and quantity in OI. Here, we conduct a systematic review and meta-analysis of published studies to investigate the efficacy of stem cell therapy to rescue bone brittleness in mouse models of OI. Identified studies included bone marrow, mesenchymal stem cells, and human fetal stem cells. Effect size of fracture incidence, maximum load, stiffness, cortical thickness, bone volume fraction, and raw engraftment rates were pooled in a random-effects meta-analysis. Cell type, cell number, injection route, mouse age, irradiation, anatomical bone, and follow up time were considered as moderators. It was not possible to investigate further parameters due to the lack of standards of investigation between the studies. Despite the use of oim mice in the majority of the investigations considered and the lack of sham mice as control, this study demonstrates the promising potential of stem cell therapy to reduce fractures in OI. Although their low engraftment, cell therapy in mouse models of OI had a beneficial effect on maximum load, but not on stiffness, cortical thickness and bone volume. These parameters all depend on bone geometry and do not inform on its material properties. Being bone fractures the primary symptom of OI, there is a critical need to measure the fracture toughness of OI bone treated with stem cells to assess the actual efficacy of the treatment to rescue OI bone brittleness.

Poor bone matrix quality: What can be done about it?

PURPOSE OF THE REVIEW

Bone's ability to withstand load resisting fracture and adapting to it highly depends on the quality of its matrix and its regulators. This review focuses on the contribution of bone quality to fracture resistance and possible therapeutic targets for skeletal fragility in aging and disease.

RECENT FINDINGS

The highly organized, hierarchical composite structure of bone extracellular matrix together with its (re)modeling mechanisms and microdamage dynamics determines its stiffness, strength, and toughness. Aging and disease affect the biological processes regulating bone quality, thus resulting in defective extracellular matrix and bone fragility. Targeted therapies are being developed to restore bone's mechanical integrity. However, their current limitations include low tissue selectivity and adverse side effects. Biological and mechanical insights into the mechanisms controlling bone quality, together with advances in drug delivery and studies in animal models, will accelerate the development and translation to clinical application of effective targeted-therapeutics for bone fragility.

Increased cochlear otic capsule thickness and intracortical canal porosity in the oim mouse model of osteogenesis imperfecta

Osteogenesis imperfecta (OI or brittle bone disease) is a group of genetic disorders of the connective tissues caused mainly by mutations in the genes encoding collagen type I. Clinical manifestations of OI include skeletal fragility, bone deformities, and severe functional disabilities, such as hearing loss. Progressive hearing loss, usually beginning in childhood, affects approximately 70% of people with OI with more than half of the cases involving the inner ear. There is no cure for OI nor a treatment to ameliorate its corresponding hearing loss, and very little is known about the properties of OI ears. In this study, we investigate the morphology of the otic capsule and the cochlea in the inner ear of the oim mouse model of OI. High-resolution 3D images of 8-week old oim and WT inner ears were acquired using synchrotron microtomography. Volumetric morphometric measurements were conducted for the otic capsule, its intracortical canal network and osteocyte lacunae, and for the cochlear spiral ducts. Our results show that the morphology of the cochlea is preserved in the oim ears at 8 weeks of age but the otic capsule has a greater cortical thickness and altered intracortical bone porosity, with a larger number and volume density of highly branched canals in the oim otic capsule. These results portray a state of compromised bone quality in the otic capsule of the oim mice that may contribute to their hearing loss.

Men and women affected by Sars-CoV-2 pneumonia: same CT features but different outcome

AIM

To compare the computed tomography (CT) features of Sars-CoV-2 pneumonia between the two sexes and among different age groups.

MATERIALS AND METHODS

Consecutive patients (n=331) who presented to the emergency department and underwent chest CT and reverse transcription polymerase chain reaction (RT-PCR) with a time interval <7 days, which were subsequently found to be consistent with Sars-CoV-2 infection, were enrolled retrospectively. Two experienced radiologists evaluated the images in consensus, recording the number of pulmonary lobes with ground-glass opacities and with consolidation. A CT score was subsequently calculated based on the percentage involvement of each lobe. Clinical symptoms, comorbidities, and level of required hospitalisation were noted. In-hospital mortality was recorded and analysed via the Kaplan-Meier estimator.

RESULTS

Males and females had the same age distribution. No statistically significant difference was found in the analysed CT features and in the CT score (p=0.31) between the sexes. More females were affected by two or more comorbidities (17.1% versus 7.5%, p=0.024), all comorbidities except diabetes were more prevalent in females. Women had a higher probability to be discharged home and a lower probability to be admitted to the intensive care unit (ICU; p=0.008), in-hospital mortality was inferior (13.5% versus 22%).

CONCLUSION

Despite more comorbidities, women had lower hospital admission and mortality, which was independent of CT findings between both sexes.

Age and Sex Differences in Load-Induced Tibial Cortical Bone Surface Strain Maps

Bone adapts its architecture to the applied load; however, it is still unclear how bone mechano‐adaptation is coordinated and why potential for adaptation adjusts during the life course. Previous animal models have suggested strain as the mechanical stimulus for bone adaptation, but yet it is unknown how mouse cortical bone load‐related strains vary with age and sex. In this study, full‐field strain maps (at 1 N increments up to 12 N) on the bone surface were measured in young, adult, and old (aged 10, 22 weeks, and 20 months, respectively), male and female C57BL/6J mice with load applied using a noninvasive murine tibial model. Strain maps indicate a nonuniform strain field across the tibial surface, with axial compressive loads resulting in tension on the medial side of the tibia because of its curved shape. The load‐induced surface strain patterns and magnitudes show sexually dimorphic changes with aging. A comparison of the average and peak tensile strains indicates that the magnitude of strain at a given load generally increases during maturation, with tibias in female mice having higher strains than in males. The data further reveal that postmaturation aging is linked to sexually dimorphic changes in average and maximum strains. The strain maps reported here allow for loading male and female C57BL/6J mouse legs in vivo at the observed ages to create similar increases in bone surface average or peak strain to more accurately explore bone mechano‐adaptation differences with age and sex. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

SAT0281 BIOSAMPLES FROM AT RISK SSC PATIENTS SHOW CLASSIC PATHOLOGICAL SIGNS OF SCLERODERMA: OPPORTUNITY FOR DIAGNOSIS OF PRE-CLINICAL SSC

Background:

The VEDOSS study has recently indicated that more than 80% of patients affected by Raynaud’s phenomenon (RP) with specific SSc auto-antibodies and capillaroscopy changes satisfied ACR/EULAR 2013 criteria within 5 years. These data suggest that there is a window of opportunity for early detection of SSc in these patients.

Objectives:

Here we aimed to determine whether sera, skin biopsies and skin fibroblasts cultured from these patients showed any biomarker sign of SSc.

Methods:

Fifty-nine at risk patients identified by having RP and SSc auto-antibodies or capillaroscopy pattern (or both) were enrolled in the Kennedy national inception cohort. Sera were tested for IFN inducible chemokines (CXCL-9,10 and 11 and CCL2, 8 and 19) and biomarker of extracellular matrix turnover (ELF test), all previously shown to be increased in SSc. Further, two 3mm skin biopsies were taken from the forearms from 3 ACA+ve (anti-centromere antibodies), 3 SCL70+ve patients. One biopsy was subjected to histology analysis, including haematoxylin and eosin staining and immunohistological staining for Collagen Type 1, alpha-SMA, Caveolin 1 and CD31 as endothelial marker. The other biopsy was used to explant fibroblasts cultures. mRNA and protein were isolated from primary fibroblasts and processed for RT-qPCR and western blotting analyses.

Results:

Sera from at risk patients showed overall higher IFN inducible chemokines and ELF test (P<0.05) with bimodal distribution among patients. Skin biopsies from both ACA or SCL70+ve patients showed decreased number of CD31+ cells, increased number of myofibroblasts and increased collagen bundles within the dermis, as usually seen in SSc, compared to healthy controls. In vitro, fibroblasts from both ACA or SCL70+ve patients showed average 10-fold higher collagen mRNA levels and 31-fold increased collagen protein levels

compared to healthy control fibroblasts. Furthermore, fibroblasts from ACA or SCL70+ve patients showed limited TGF-beta induced increase in collagen and SMA expression, similar to SSc fibroblasts.

Conclusion:

Although pilot in nature, this study suggests that patients “at risk” already show biomarker signs of SSc both in their sera, at skin biopsy and fibroblast level. Longitudinal studies on patients at this stage of pre-clinical disease may inform on the stratification strategies for imminent progression to clinical manifestations, and offer both insights on pathogenesis of clinical signs and a window of opportunity for delaying the onset clinical intervention trials.

Disclosure of Interests:

rebecca ross: None declared, Ioanna Georgiou: None declared, Antonio Carriero: None declared, Giuseppina Abignano: None declared, Chris Wasson: None declared, Gemma Migneco: None declared, Ariane Herrick: None declared, Christopher Denton Grant/research support from: GlaxoSmithKline, CSL Behring, and Inventiva, Consultant of: Medscape, Roche-Genentech, Actelion, GlaxoSmithKline, Sanofi Aventis, Inventiva, CSL Behring, Boehringer Ingelheim, Corbus Pharmaceuticals, Acceleron, Curzion and Bayer, Francesco Del Galdo: None declared

THU0150 INTERSTITIAL LUNG DISEASE RELATED TO RHEUMATOID ARTHRITIS. WHAT DO WE DON’T KNOW? THE LIRA STUDY (LUNG INVOLVEMENT IN RHEUMATOID ARTHRITIS)

Background:

Interstitial lung disease (ILD) is one of the more frequent and potentially severe extra-articular manifestation of rheumatoid arthritis (RA). ILD significantly decreases the survival and quality of life of patients and influences the treatment approach to the patient.

Despite its clinical relevance, the prevalence, incidence and survival of RA-ILD is unknown and supposed on the base of retrospective data or registry-based studies.

Objectives:

For the first time, the Lung Involvement in Rheumatoid Arthritis (LIRA) study aims to investigate epidemiology, features and prognosis of RA-ILD patients in a prospective international multicentre study.

Methods:

All RA patients referring to the involved centres will be evaluated every six months with a digital stethoscope and a software able to identify velcro crackles with a diagnostic accuracy of 83.9% (VECTOR). In fact, velcro crackles are virtually identified in all stages of fibrosing alveolitis like RA-ILD, and their search is as a simple and reliable method to screening patients to be undergone to high resolution computed tomography (HRCT).

For each patient, clinical and serological data are recorded at baseline and every six months; when velcro crackles or other conditions suspicious for ILD, such as cough or dyspnoea, are detected, a HRCT is requested to confirm ILD. Patients with ILD periodically perform pulmonary function tests to monitor lung function evolution.

Results:

At now, 205 RA patients have been enrolled (female/male 161/44, mean age 64.8±12.9 years, mean disease duration 14.2±8.9 years), anti-citrullinated peptides antibodies (ACPA) and rheumatoid factor (RF) were positive in 77.1% and 78.1%, respectively. The prevalence of ILD was 21% (43 patients). In other 13 patients the HRCT is ongoing; therefore, we could suppose up to a prevalence of 27.3%. Patients with ILD were symptomatic in 53.5% of cases (23 patients), they are more frequently males and were older than patients without ILD (mean age 73.2±7.4 and 62.7±13.2; p<0.0001, female/male ratio 139/23 vs 22/21; p<0.0001) without significant differences regarding disease duration, positivity for ACPA or RF.

Conclusion:

The prevalence and the incidence of RA-ILD is still not well defined. Preliminary data of our study confirm a prevalence of ILD higher than 20%, patients are asymptomatic in almost the half of cases and more frequently males and elderly. Our study can help to define the clinical history of these patients, the possible association with clinical and serological features and the supposed role of some drugs.

References:

[1]Manfredi A, et al. Diagnostic accuracy of a velcro sound detector (VECTOR) for interstitial lung disease in rheumatoid arthritis patients: the InSPIRAtE validation study (INterStitial pneumonia in rheumatoid ArThritis with an electronic device). BMC Pulm Med. 2019;19:111.

[2]Bendstrup E, et al. Interstitial Lung Disease in Rheumatoid Arthritis Remains a Challenge for Clinicians. J Clin Med. 2019:8

Disclosure of Interests:

Marco Sebastiani: None declared, Caterina Vacchi: None declared, Giulia Cassone: None declared, Fabiola Atzeni: None declared, Martina Biggioggero: None declared, Antonio Carriero: None declared, Gian Luca Erre: None declared, Anna Laura Fedele: None declared, Federica Furini: None declared, Paola Tomietto: None declared, Vincenzo Venerito: None declared, Belén Atienza-Mateo: None declared, Giovanni Della Casa: None declared, Stefania Cerri: None declared, Gilda Sandri: None declared, Adalgisa Palermo: None declared, Elena Galli: None declared, Fabrizio Pancaldi: None declared, Miguel A González-Gay Grant/research support from: Pfizer, Abbvie, MSD, Speakers bureau: Pfizer, Abbvie, MSD, Carlo Salvarani: None declared, Andreina Manfredi: None declared

X-ray fluorescence microscopy: A method of measuring ion concentrations in the ear

This technical note describes synchrotron x-ray fluorescence microscopy (XFM) as a method for measuring the concentrations of different elements in cross-sections of the ear at extremely high resolution. This method could be of great importance for addressing many open questions in hearing research. XFM uses synchrotron radiation to evoke emissions from many biologically relevant elements in the tissue. The intensity and wavelength of the emitted radiation provide a fingerprint of the tissue composition that can be used to measure the concentration of the elements in the sampled location. Here, we focus on energies that target biologically-relevant elements of the periodic table between magnesium and zinc. Since a highly focused x-ray beam is used, the spot size is well below 1 μm and the samples can be scanned at a nanometer lateral resolution. This study shows that measurement of the concentrations of different elements is possible in a mid-modiolar cross-section of a mouse cochlea. Images are presented that indicate potassium and chloride "hot spots" in the spiral ligament and the spiral limbus, providing experimental evidence for the potassium recycling pathway and showing the cochlear structures involved. Scans of a section obtained from the incus, one of the middle ear ossicles, in a developing mouse have shown that zinc is not uniformly distributed This supports the hypothesis that zinc plays a special role in the process of ossification. Although limited by sophisticated sample preparation and sectioning, the method provides ample exciting opportunities, to understand the role of genetics and epigenetics on hearing mechanisms in ontogeny and phylogeny.

Conversion factors for effective dose and organ doses with the air kerma area product in patients undergoing percutaneous transhepatic biliary drainage and trans arterial chemoembolization

Conversion factors used to estimate effective (E) and organ doses (H_T) from air Kerma area product (KAP) are required to estimate population doses in percutaneous transhepatic biliary drainage (PTBD) and trans arterial chemoembolization (TACE) interventional procedures. In this study, E and H_T for ten critical organs/tissues, were derived in 64 PTBD and 48 TACE procedures and in 14,540 irradiation events from dosimetric, technical and geometrical information included in the radiation dose structured report using the PCXMC Monte Carlo model, and the ICRP 103 organ weighting factors. Conversion factors of: 0.13; 0.19; 0.26 and 0.32 mSv Gy^-1 cm^-2 were established for irradiation events characterized by a Cu filtration of 0.0; 0.1; 0.4 and 0.9 mm, respectively. While a single coefficient of conversion is not able to provide estimates of E with enough accuracy, a high agreement is obtained between E estimated through Monte Carlo methods and E estimated through E/KAP conversion factors accounting separately for the different modes of fluoroscopy and the fluorography component of the procedures. An algorithm for the estimation of effective and organ doses from KAP has been established in biliary procedures which considers the Cu filtration in the X-ray irradiation events. A similar algorithm could be easily extended to other interventional procedures and incorporated in radiation dose monitoring systems to provide dosimetric estimates automatically with enough accuracy to assess population doses.

Design and characterization of a porous pouch to prevent peritoneal adhesions during in vivo vascular graft maturation

Vein grafts for coronary artery bypass are not available in more than 30% of patients due to prior use or systemic vascular diseases. Tissue engineered vascular grafts (TEVGs) have shown promise, but intimal hyperplasia and graft thrombosis are still concerns when grafted in small-diameter arteries. In this study, we utilized the peritoneal cavity as an "in vivo" bioreactor to recruit autologous cells to electrospun conduits enclosed within porous pouches to improve the response after grafting. Specifically, we designed a new poly (ethylene glycol)-based pouch to avoid adhesion to the peritoneal wall and still allow the necessary peritoneal fluid to reach the enclosed conduit. The pouch mechanics in compression and bending were determined through experiments and finite element simulations to optimize the pouch design. This included poly (ethylene glycol) concentration, pore density, and pouch size. We demonstrated that the optimized pouch was able to withstand the estimated forces applied in the rat peritoneal cavity and it allowed maturation of the enclosed electrospun conduit. This pouch significantly reduced peritoneal adhesion formation compared to polytetrafluoroethylene pouches that have been used previously, which overcomes this potential limitation to clinical translation. After aortic grafting of pre-conditioned conduits, patent grafts with limited intimal hyperplasia were observed. Overall, this study demonstrated a new pouch design that allows the in vivo bioreactor strategy to be used for vascular tissue engineering without the potential side effect of peritoneal adhesion formation.

Delivery of selective internal radiation therapy complicated by variant hepatic vascular anatomy

“Difficult vascular anatomy” is a challenge for Interventional Radiologists especially in liver directed therapies such as trans arterial radio embolization.

Trans arterial radio embolization is a long and difficult procedure in which the basic knowledge of hepatic and gastro-enteric vascularization, with its high degree of variations, is very important in order to correctly administer the therapeutic drug selectively.

In this report, we present a case of an atypical patient affected by an unresectable hepatocellular carcinoma, candidate for Radio-embolization treatment.

His vascular anatomy was very difficult to manage, but the Interventional Radiologist was not only able to go over the “difficult anatomy,” but also to take advantage of it.

Variability of the discrepancy between manufacturer and measured CTDI100 values by scanner type, acquisition parameters and phantom size

According to the EU directive 2013/59, the computed tomography (CT) equipments shall be able to inform the practitioner of parameters for assessing the patient dose. The aim of this study was to measure the accuracy of the CTDI₁₀₀ with respect to the values stipulated in the manufacturer manual for different manufacturers/models of CT and to assess the impact of acquisition parameters on CTDI₁₀₀ accuracy. Ten CT from 4 different manufacturers were included in the study. The discrepancy with the manufacturer value CTDI₁₀₀ was checked with a dosimeter with traceable calibration. Manufacturer values for the CTDI₁₀₀ were derived from the equipment's manual. The impact of the kVp, CT model, primary collimation and phantom size on the discrepancy of the CTDI₁₀₀, was assessed by a four-way ANOVA. All the factors had a statistically significant impact on CTDI₁₀₀ discrepancy (P < 0.05). In a head to head comparison, the greater discrepancies were found on average for 80 kV (15.4 ± 10.7%), sixteen channels CT (10.3 ± 5.1%) and for thick collimations (13.2 ± 6.8%), whilst no significant differences were found between head and body phantoms. For sixteen channels CT and acquisition protocols involving the use of low kV or thick primary collimation, the discrepancies with the manufacturer value CTDI₁₀₀ can be higher than 20%, which is the suspension level indicated in the EC RP N.162 Publication. This suggests the need of individual calibration of CT X-ray tubes by the manufacturers and the necessity of including this check in the quality control programs for CT.

Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response

Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation.

Spatial relationship between bone formation and mechanical stimulus within cortical bone: Combining 3D fluorochrome mapping and poroelastic finite element modelling

Bone is a dynamic tissue and adapts its architecture in response to biological and mechanical factors. Here we investigate how cortical bone formation is spatially controlled by the local mechanical environment in the murine tibia axial loading model (C57BL/6). We obtained 3D locations of new bone formation by performing ‘slice and view’ 3D fluorochrome mapping of the entire bone and compared these sites with the regions of high fluid velocity or strain energy density estimated using a finite element model, validated with ex-vivo bone surface strain map acquired ex-vivo using digital image correlation. For the comparison, 2D maps of the average bone formation and peak mechanical stimulus on the tibial endosteal and periosteal surface across the entire cortical surface were created. Results showed that bone formed on the periosteal and endosteal surface in regions of high fluid flow. Peak strain energy density predicted only the formation of bone periosteally. Understanding how the mechanical stimuli spatially relates with regions of cortical bone formation in response to loading will eventually guide loading regime therapies to maintain or restore bone mass in specific sites in skeletal pathologies.

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3D spatial representation of new bone formation after loading is shown by fluorochrome mapping of the entire mouse tibia

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Regions of new bone formation spatially associate with regions of high strain and fluid mechanical stimulus in a FE model

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The FE model was validated with the strains on the bone surface determined ex-vivo using digital image correlation

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Regions of new bone formation co-localize in sites of peak fluid flow, both endosteally and periosteally

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Peak strain energy density was able to predict only periosteal bone formation

Conversion factors of effective and equivalent organ doses with the air kerma area product in patients undergoing coronary angiography and percutaneous coronary interventions

To derive effective dose (E), organ dose (H_T) and conversion factors with the air kerma area product (KAP) in coronary angiography (CA) and percutaneous coronary intervention (PCI) by the radial route, using the ICRP 103 tissue weighting factors. The study included 34 patients referred for CA and 31 for PCI. E and H_T were derived from in-the-field KAP measurements using Montecarlo methods. Median KAP of 23.2 and 56.8Gycm² and E of 6.9 and 20.0mSv were found for CA and PCI, respectively. Mean KAP and E were significantly higher in males than in females (52.4±40.0 vs 32.3±16.6Gycm²; p=0.02) and (16.8±13.6 vs 10.7±5.8mSv; p=0.04). KAP (r=0.39; p=0.001) and E (r=0.34; p=0.005) showed a significant correlation with the patient's weight. Conversion factors between KAP and E (E/KAP) were 0.30±0.04mSvGy^-1cm^-2 for CA and 0.33±0.05mSvGy^-1cm^-2 for PCI. No significant differences in the E/KAP between males and females were found (0.31±0.05 vs 0.33±0.05; p=0.08). Again, no significant correlation was found between E/KAP and patient's weight (r=0.23; p=0.07). The correlation between E and KAP was excellent for CA (r=0.99) and PCI (r=0.96). The correlation between H_T and KAP ranged from r=0.87 to r=1 and from r=0.71 to r=0.98 for CA and PCI, respectively. A single factor, the total KAP, could be used for a specific acquisition protocol to reliably estimate E and H_T without the need of a patient's specific analysis. Conversion factors might be installation, X-ray beam quality or protocol dependent.

Impact of polymorphism rs7041 and rs4588 of Vitamin D Binding Protein on the extent of coronary artery disease

BACKGROUND AND AIM

25-hydroxyvitamin D deficiency represents a widespread social problem but also an emerging risk factor for cardiovascular disease. Genetic variants of the Vitamin D Binding Protein (VDBP), the main transporter of vitamin D in the bloodstream, have been shown to account for a significant variability in the levels and systemic effects of vitamin D. We investigated whether the single nucleotide polymorphisms, rs7041 and rs4588, of VDBP are associated to the prevalence and extent of coronary artery disease.

METHODS AND RESULTS

A consecutive cohort of patients undergoing coronary angiography in a single centre were included. Significant CAD was defined as at least 1 stenosis >50%, severe CAD for as left main and/or three-vessel disease. VDBP genetic status was assessed by polymerase chain reaction and restriction fragment length polymorphism technique. We included 1080 patients, 57% carried the mutated G allele of rs7041, whereas 22% carried the A allele of rs4588. Higher levels of C- reactive protein were observed in the carriers of G allele of rs7041 (p = 0.02), whereas 25-hydroxyvitamin D levels were similar across groups. A higher prevalence of lesions in the left anterior descending artery and a longer lesion length were observed in "A" carriers for rs4588 (p = 0.04 and p = 0.03, respectively). On the contrary, a higher prevalence of bifurcation lesions and chronic occlusions was observed in G carriers (p = 0.002 and p = 0.01 respectively). Both polymorphisms of VDBP did not affect the prevalence of CAD (rs7041: 79.1% TT vs 80.3% TG vs 78.5% GG, p = 0.81; rs4588 = 80.3% CC vs 78.5% AC + AA, p = 0.49) and severe CAD, (rs7041: 31.1% TT % vs 31.3% TG vs 30.6% GG, p = 0.88; rs4588: 32.2% CC vs 29.3% AC + AA, p = 0.31). Results were confirmed at multivariate analysis, for both rs7041 and rs4588. However, when including the levels of 25-hydroxyvitamin D in the multivariate model, we observed that 25(OH)D status and not genetic variants of VDBP were significantly associated with CAD (25-hydroxyvitamin D OR [95% CI] = 0.99 [0.97-1.0], p = 0.05; rs7041 TG: OR [95% CI] = 1.26 [0.73-2.19], p = 0.41; rs7041 GG: OR [95% CI] = 1.25 [0.82-1.91], p = 0.30; rs4588 AC + AA: OR [95% CI] = 0.76 [0.51-1.13], p = 0.18).

CONCLUSION

This study showed in a large cohort of patients undergoing coronary angiography, that the polymorphisms rs7041 and rs4588 of VDBP are not associated with the levels of 25-hydroxyvitamin D nor with the prevalence and extent of CAD. In fact, 25-hydroxyvitamin D levels but not VDBP genetic status independently predicted the occurrence of coronary lesions at angiography.

Nailfold capillaroscopic changes in patients with idiopathic pulmonary arterial hypertension and systemic sclerosis-related pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) represents one of the main clinical expressions of the vascular changes in systemic sclerosis (SSc). Lung microvascular changes can play a role in the pathogenesis of idiopathic PAH (IPAH) also. The aim of this study is to investigate the presence of capillaroscopic abnormalities in patients with IPAH and to evaluate the differences in capillary nailfold changes between patients with IPAH and patients with SSc with and without PAH.

METHODS

39 SSc patients (19 with PAH - SSc-PAH and 20 without - SSc-noPAH), 21 subjects with IPAH and 20 healthy subjects were recruited. PAH was diagnosed by right heart catheterization. Nailfold videocapillaroscopy was performed (NVC) in all recruited subjects; capillary quantitative parameters (loops length and width, capillary density, neoangiogenesis) were evaluated and a semiquantitative scoring was used (normal, minor or major abnormalities for healthy controls and IPAH subjects and specific patterns - early, active and late - for SSc subjects) to define microvascular alterations.

RESULTS

The presence of capillaroscopic abnormalities was detected in 38,1% subjects with IPAH; particularly, compared to healthy controls, capillary density was significantly lower (7,5±1,65loops/mm vs 9±1,37loops/mm p<0,05) and mean capillary width was significantly higher (21±13μm vs 17±3μm p<0,05). A more severe NVC pattern (active/late) was described. SSc-PAH patients compared to SSc-noPAH patients (73,2% vs 50% respectively, p<0,05), with a significantly lower capillary density (5,64±1,9loops/mm vs 6,5±1,3loops/mm p<0,05) and a significantly higher capillary width (55±7μm vs 35±8μm - p<0,05) and mean number of neoangiogenesis (N/mm) (1±0,33 vs 0,2±0,22 respectively p<0,05).

CONCLUSIONS

These data, beyond to confirm the role of microvascular damage in SSc-related PAH, support the hypothesis of systemic microvascular involvement in IPAH also, which can be detected by NVC, although further studies are needed to establish whether the changes in the systemic microcirculation are causal or consequential to PAH.

Altered Bone Mechanics, Architecture and Composition in the Skeleton of TIMP-3-Deficient Mice

Tissue inhibitor of metalloproteinases-3 (TIMP-3) maintains a healthy extracellular matrix by regulating matrix metalloproteinases (MMP), disintegrin-metalloproteinases (ADAM), and disintegrin-metalloproteinases with ThromboSpondin-like motifs (ADAMTS) activity. Currently, there is a need for a comprehensive understanding of the effects of TIMP-3 on the bone quality and integrity. In this study, we examined the mechanical, morphological, and compositional properties of TIMP-3 knock out (Timp-3 ^-/-) mouse bone. We hypothesize that the lack of TIMP-3 plays an important role in maintaining the overall bone integrity. Mechanical properties of humeri, lumbar vertebrae, and femurs from Timp-3 ^-/- mice were determined using 3-point bending, compression, and notched 3-point bending, respectively. Morphological properties of the humeral cortical and trabecular bone and the caudal vertebrae cortical bone were evaluated using micro-computed tomography, while the composition of the femoral cortical and trabecular bone was examined using Fourier transform infrared spectroscopic imaging. Our results revealed that the integrity of the Timp-3 ^-/- bone is compromised due to changes in its composition, structure, and mechanics. Reductions in the yield and ultimate load and stress capacity, and loss in bone fracture toughness were attributed to reduced density and thickness, and increased porosity of cortical bone. Thin trabeculae were dense, highly connected, and closely packed in Timp-3 ^-/- bone. Furthermore, altered cortical and trabecular bone mineralization and increased compositional heterogeneity were found in Timp-3 ^-/- bone, all being indicative of high bone remodeling. In conclusion, this study suggests that the lack of TIMP-3 is detrimental to bone development and maintenance.

Overexpression of TIMP-3 in Chondrocytes Produces Transient Reduction in Growth Plate Length but Permanently Reduces Adult Bone Quality and Quantity

Bone development and length relies on the growth plate formation, which is dependent on degradative enzymes such as MMPs. Indeed, deletion of specific members of this enzyme family in mice results in important joint and bone abnormalities, suggesting a role in skeletal development. As such, the control of MMP activity is vital in the complex process of bone formation and growth. We generated a transgenic mouse line to overexpress TIMP3 in mouse chondrocytes using the Col2a1-chondrocyte promoter. This overexpression in cartilage resulted in a transient shortening of growth plate in homozygote mice but bone length was restored at eight weeks of age. However, tibial bone structure and mechanical properties remained compromised. Despite no transgene expression in adult osteoblasts from transgenic mice in vitro, their differentiation capacity was decreased. Neonates, however, did show transgene expression in a subset of bone cells. Our data demonstrate for the first time that transgene function persists in the chondro-osseous lineage continuum and exert influence upon bone quantity and quality.

Animal models of osteogenesis imperfecta: applications in clinical research

Osteogenesis imperfecta (OI), commonly known as brittle bone disease, is a genetic disease characterized by extreme bone fragility and consequent skeletal deformities. This connective tissue disorder is caused by mutations in the quality and quantity of the collagen that in turn affect the overall mechanical integrity of the bone, increasing its vulnerability to fracture. Animal models of the disease have played a critical role in the understanding of the pathology and causes of OI and in the investigation of a broad range of clinical therapies for the disease. Currently, at least 20 animal models have been officially recognized to represent the phenotype and biochemistry of the 17 different types of OI in humans. These include mice, dogs, and fish. Here, we describe each of the animal models and the type of OI they represent, and present their application in clinical research for treatments of OI, such as drug therapies (ie, bisphosphonates and sclerostin) and mechanical (ie, vibrational) loading. In the future, different dosages and lengths of treatment need to be further investigated on different animal models of OI using potentially promising treatments, such as cellular and chaperone therapies. A combination of therapies may also offer a viable treatment regime to improve bone quality and reduce fragility in animals before being introduced into clinical trials for OI patients.

Stenosi carotidea: Confronto tra angio-RM e angio-TC spirale

A preliminary study comparing three dimensional time of flight (TOF 3D) Magnetic Resonance angiography (MRA) and spiral CT angiography (SCTA) in the detection and evaluation of internal carotid stenosis.

Digital subtraction angiography (DSA) was the gold standard.

Twenty patients with clinical signs of cerebrovascular insufficiency underwent MRA, SCTA and DSA within a three day period. Both internal carotid arteries were evaluated for absence or degree of stenosis.

Sensitivity, specificity, diagnostic accuracy, concordance, overstimation and understimation were assessed. MRA showed a higher sensitivity, specificity, diagnostic accuracy and concordance compared to SCTA (92% versus 80%, 98,2% versus 96,4%, 96,3% versus 88%, respectively). MRA demonstrated a 5% overstimation rate whereas SCTA demonstrated a 7,5% understimation rate. These differences are not statistically significant.

These results suggest that MRA is the more useful, non invasive modality for the detection and evaluation of the internal carotid artery with a greater than 70% stenoses.

The anabolic action of intermittent parathyroid hormone on cortical bone depends partly on its ability to induce nitric oxide-mediated vasorelaxation in BALB/c mice

There is strong evidence that vasodilatory nitric oxide (NO) donors have anabolic effects on bone in humans. Parathyroid hormone (PTH), the only osteoanabolic drug currently approved, is also a vasodilator. We investigated whether the NO synthase inhibitor L‐NAME might alter the effect of PTH on bone by blocking its vasodilatory effect. BALB/c mice received 28 daily injections of PTH[1–34] (80 µg/kg/day) or L‐NAME (30 mg/kg/day), alone or in combination. Hindlimb blood perfusion was measured by laser Doppler imaging. Bone architecture, turnover and mechanical properties in the femur were analysed respectively by micro‐CT, histomorphometry and three‐point bending. PTH increased hindlimb blood flow by >30% within 10 min of injection (P < 0.001). Co‐treatment with L‐NAME blocked the action of PTH on blood flow, whereas L‐NAME alone had no effect. PTH treatment increased femoral cortical bone volume and formation rate by 20% and 110%, respectively (P < 0.001). PTH had no effect on trabecular bone volume in the femoral metaphysis although trabecular thickness and number were increased and decreased by 25%, respectively. Co‐treatment with L‐NAME restricted the PTH‐stimulated increase in cortical bone formation but had no clear‐cut effects in trabecular bone. Co‐treatment with L‐NAME did not affect the mechanical strength in femurs induced by iPTH. These results suggest that NO‐mediated vasorelaxation plays partly a role in the anabolic action of PTH on cortical bone. © 2016 The Authors. Cell Biochemistry and Function published by John Wiley & Sons, Ltd.

Phospho1 deficiency transiently modifies bone architecture yet produces consistent modification in osteocyte differentiation and vascular porosity with ageing

PHOSPHO1 is one of principal proteins involved in initiating bone matrix mineralisation. Recent studies have found that Phospho1 KO mice (Phospho1-R74X) display multiple skeletal abnormalities with spontaneous fractures, bowed long bones, osteomalacia and scoliosis. These analyses have however been limited to young mice and it remains unclear whether the role of PHOSPHO1 is conserved in the mature murine skeleton where bone turnover is limited. In this study, we have used ex-vivo computerised tomography to examine the effect of Phospho1 deletion on tibial bone architecture in mice at a range of ages (5, 7, 16 and 34 weeks of age) to establish whether its role is conserved during skeletal growth and maturation. Matrix mineralisation has also been reported to influence terminal osteoblast differentiation into osteocytes and we have also explored whether hypomineralised bones in Phospho1 KO mice exhibit modified osteocyte lacunar and vascular porosity. Our data reveal that Phospho1 deficiency generates age-related defects in trabecular architecture and compromised cortical microarchitecture with greater porosity accompanied by marked alterations in osteocyte shape, significant increases in osteocytic lacuna and vessel number. Our in vitro studies examining the behaviour of osteoblast derived from Phospho1 KO and wild-type mice reveal reduced levels of matrix mineralisation and modified osteocytogenic programming in cells deficient in PHOSPHO1. Together our data suggest that deficiency in PHOSPHO1 exerts modifications in bone architecture that are transient and depend upon age, yet produces consistent modification in lacunar and vascular porosity. It is possible that the inhibitory role of PHOSPHO1 on osteocyte differentiation leads to these age-related changes in bone architecture. It is also intriguing to note that this apparent acceleration in osteocyte differentiation evident in the hypomineralised bones of Phospho1 KO mice suggests an uncoupling of the interplay between osteocytogenesis and biomineralisation. Further studies are required to dissect the molecular processes underlying the regulatory influences exerted by PHOSPHO1 on the skeleton with ageing.

Effects of normal and abnormal loading conditions on morphogenesis of the prenatal hip joint: application to hip dysplasia

Joint morphogenesis is an important phase of prenatal joint development during which the opposing cartilaginous rudiments acquire their reciprocal and interlocking shapes. At an early stage of development, the prenatal hip joint is formed of a deep acetabular cavity that almost totally encloses the head. By the time of birth, the acetabulum has become shallower and the femoral head has lost substantial sphericity, reducing joint coverage and stability. In this study, we use a dynamic mechanobiological simulation to explore the effects of normal (symmetric), reduced and abnormal (asymmetric) prenatal movements on hip joint shape, to understand their importance for postnatal skeletal malformations such as developmental dysplasia of the hip (DDH). We successfully predict the physiological trends of decreasing sphericity and acetabular coverage of the femoral head during fetal development. We show that a full range of symmetric movements helps to maintain some of the acetabular depth and femoral head sphericity, while reduced or absent movements can lead to decreased sphericity and acetabular coverage of the femoral head. When an abnormal movement pattern was applied, a deformed joint shape was predicted, with an opened asymmetric acetabulum and the onset of a malformed femoral head. This study provides evidence for the importance of fetal movements in the prevention and manifestation of congenital musculoskeletal disorders such as DDH.

Reference point indentation is not indicative of whole mouse bone measures of stress intensity fracture toughness

Bone fragility is a concern for aged and diseased bone. Measuring bone toughness and understanding fracture properties of the bone are critical for predicting fracture risk associated with age and disease and for preclinical testing of therapies. A reference point indentation technique (BioDent) has recently been developed to determine bone's resistance to fracture in a minimally invasive way by measuring the indentation distance increase (IDI) between the first and last indentations over cyclic indentations in the same position. In this study, we investigate the relationship between fracture toughness KC and reference point indentation parameters (i.e. IDI, total indentation distance (TID) and creep indentation distance (CID)) in bones from 38 mice from six types (C57Bl/6, Balb, oim/oim, oim/+, Phospho1(-/-) and Phospho1 wild type counterpart). These mice bone are models of healthy and diseased bone spanning a range of fracture toughness from very brittle (oim/oim) to ductile (Phospho1(-/-)). Left femora were dissected, notched and tested in 3-point bending until complete failure. Contralateral femora were dissected and indented in 10 sites of their anterior and posterior shaft surface over 10 indentation cycles. IDI, TID and CID were measured. Results from this study suggest that reference point indentation parameters are not indicative of stress intensity fracture toughness in mouse bone. In particular, the IDI values at the anterior mid-diaphysis across mouse types overlapped, making it difficult to discern differences between mouse types, despite having extreme differences in stress intensity based toughness measures. When more locations of indentation were considered, the normalised IDIs could distinguish between mouse types. Future studies should investigate the relationship of the reference point indentation parameters for mouse bone in other material properties of the bone tissue in order to determine their use for measuring bone quality.

Thompson calf squeezing test: clinical and ultrasound correlations in the follow up of Achille's tenorraphy

In the follow up of Achille's tenorraphy, negativization of Thompson calf queezing test is not always omogeneous and absolute. Aim of the paper is to correlate Thompson test to different anatomical-ultrasound and functional parameters. We investigated clinically and by ultrasound 61 patients operated on of Achille's tenorraphy at Novara Hospital with follow-up of 10 to 46 months. Negative controls were contralateral tendons. We excluded patients with previous and/or contralateral Achille's tendon ruptures, those operated after 7 days, diabetics or with autoimmune diseases, if used topic steroids, < 18 years, those rejecting the study. Measured parameters were: age, gender, height, weight, side, open vs percutaneous approach, time from operation, neutral angle and range of motion of the ankle, maximal circumference of the leg, Single Heel Rise Test, Visual-Analogue-Scale Foot and Ankle (VAS FA) score; with ultrasound: length of tendons, mio-tendinous U.S.-structure, dynamic diastasis of tendon scar, tendon sliding. Thompson test is positive if no plantar-flexion of the foot occurs at calf squeezing, negative if plantar-flexion is normal (75% patients) and intermediate if reduced or slight reactive (25%).We found correlation of Thompson test with age (p<0,05) and with tendon length (p>0,05), being intermediate tests more represented in older patients and in those with longer healed tendons. In conclusion post-operative negativization of Thompson test can be incomplete as observed in older patients and in those healed with elongated tendon.

How tough is brittle bone? Investigating osteogenesis imperfecta in mouse bone

The multiscale hierarchical structure of bone is naturally optimized to resist fractures. In osteogenesis imperfecta, or brittle bone disease, genetic mutations affect the quality and/or quantity of collagen, dramatically increasing bone fracture risk. Here we reveal how the collagen defect results in bone fragility in a mouse model of osteogenesis imperfecta (oim), which has homotrimeric α1(I) collagen. At the molecular level, we attribute the loss in toughness to a decrease in the stabilizing enzymatic cross-links and an increase in nonenzymatic cross-links, which may break prematurely, inhibiting plasticity. At the tissue level, high vascular canal density reduces the stable crack growth, and extensive woven bone limits the crack-deflection toughening during crack growth. This demonstrates how modifications at the bone molecular level have ramifications at larger length scales affecting the overall mechanical integrity of the bone; thus, treatment strategies have to address multiscale properties in order to regain bone toughness. In this regard, findings from the heterozygous oim bone, where defective as well as normal collagen are present, suggest that increasing the quantity of healthy collagen in these bones helps to recover toughness at the multiple length scales.

Vitamin D deficiency induces early signs of aging in human bone, increasing the risk of fracture

Vitamin D deficiency is a widespread medical condition that plays a major role in human bone health. Fracture susceptibility in the context of low vitamin D has been primarily associated with defective mineralization of collagenous matrix (osteoid). However, bone's fracture resistance is due to toughening mechanisms at various hierarchical levels ranging from the nano- to the microstructure. Thus, we hypothesize that the increase in fracture risk with vitamin D deficiency may be triggered by numerous pathological changes and may not solely derive from the absence of mineralized bone. We found that the characteristic increase in osteoid-covered surfaces in vitamin D-deficient bone hampers remodeling of the remaining mineralized bone tissue. Using spatially resolved synchrotron bone mineral density distribution analyses and spectroscopic techniques, we observed that the bone tissue within the osteoid frame has a higher mineral content with mature collagen and mineral constituents, which are characteristic of aged tissue. In situ fracture mechanics measurements and synchrotron radiation micro-computed tomography of the crack path indicated that vitamin D deficiency increases both the initiation and propagation of cracks by 22 to 31%. Thus, vitamin D deficiency is not simply associated with diminished bone mass. Our analyses reveal the aged nature of the remaining mineralized bone and its greatly decreased fracture resistance. Through a combination of characterization techniques spanning multiple size scales, our study expands the current clinical understanding of the pathophysiology of vitamin D deficiency and helps explain why well-balanced vitamin D levels are essential to maintain bone's structural integrity.

Ex vivo determination of bone tissue strains for an in vivo mouse tibial loading model

Previous studies introduced the digital image correlation (DIC) as a viable technique for measuring bone strain during loading. In this study, we investigated the sensitivity of a DIC system in determining surface strains in a mouse tibia while loaded in compression through the knee joint. Specifically, we examined the effect of speckle distribution, facet size and overlap, initial vertical alignment of the bone into the loading cups, rotation with respect to cameras, and ex vivo loading configurations on the strain contour maps measured with a DIC system.

We loaded tibiae of C57BL/6 mice (12 and 18 weeks old male) up to 12 N at 8 N/min. Images of speckles on the bone surface were recorded at 1 N intervals and DIC was used to compute strains. Results showed that speckles must have the correct size and density with respect to the facet size of choice for the strain distribution to be computed and reproducible. Initial alignment of the bone within the loading cups does not influence the strain distribution measured during peak loading, but bones must be placed in front of the camera with the same orientation in order for strains to be comparable. Finally, the ex vivo loading configurations with the tibia attached to the entire mouse, or to the femur and foot, or only to the foot, showed different strain contour maps.

This work provides a better understanding of parameters affecting full field strain measurements from DIC in ex vivo murine tibial loading tests.

Altered lacunar and vascular porosity in osteogenesis imperfecta mouse bone as revealed by synchrotron tomography contributes to bone fragility

Osteogenesis imperfecta (brittle bone disease) is caused by mutations in the collagen genes and results in skeletal fragility. Changes in bone porosity at the tissue level indicate changes in bone metabolism and alter bone mechanical integrity. We investigated the cortical bone tissue porosity of a mouse model of the disease, oim, in comparison to a wild type (WT-C57BL/6), and examined the influence of canal architecture on bone mechanical performance. High-resolution 3D representations of the posterior tibial and the lateral humeral mid-diaphysis of the bones were acquired for both mouse groups using synchrotron radiation-based computed tomography at a nominal resolution of 700nm. Volumetric morphometric indices were determined for cortical bone, canal network and osteocyte lacunae. The influence of canal porosity architecture on bone mechanics was investigated using microarchitectural finite element (μFE) models of the cortical bone. Bright-field microscopy of stained sections was used to determine if canals were vascular. Although total cortical porosity was comparable between oim and WT bone, oim bone had more numerous and more branched canals (p<0.001), and more osteocyte lacunae per unit volume compared to WT (p<0.001). Lacunae in oim were more spherical in shape compared to the ellipsoidal WT lacunae (p<0.001). Histology revealed blood vessels in all WT and oim canals. μFE models of cortical bone revealed that small and branched canals, typical of oim bone, increase the risk of bone failure. These results portray a state of compromised bone quality in oim bone at the tissue level, which contributes to its deficient mechanical properties.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.