Nanoscale structural mapping as a measure of maturation in the murine frontal cortex

Atomic force microscopy (AFM) is emerging as an innovative tool to phenotype the brain. This study demonstrates the utility of AFM to determine nanomechanical and nanostructural features of the murine dorsolateral frontal cortex from weaning to adulthood. We found an increase in tissue stiffness of the primary somatosensory cortex with age, along with an increased cortical mechanical heterogeneity. To characterize the features potentially responsible for this heterogeneity, we applied AFM scan mode to directly image the topography of thin sections of the primary somatosensory cortical layers II/III, IV and V/VI. Topographical mapping of the cortical layers at successive ages showed progressive smoothing of the surface. Topographical images were also compared with histochemically derived morphological information, which demonstrated the deposition of perineuronal nets, important extracellular components and markers of maturity. Our work demonstrates that high-resolution AFM images can be used to determine the nanostructural properties of cortical maturation, well beyond embryonic and postnatal development. Furthermore, it may offer a new method for brain phenotyping and screening to uncover topographical changes in early stages of neurodegenerative diseases.

Adjusting FRAX® on TBS for identification of subjects at high risk of fractures

The objective of this study was to compare the proportion of patients at high fracture risk according to FRAX® and FRAX® adjusted on TBS in patients hospitalized for a non vertebral fractures. Patients were selected from a Fracture Liaison Service FLS): clinical risk factors, bone mineral density (BMD) and TBS were assessed at the time of the fracture. Without considering the current fracture, we calculated FRAX® and FRAX® adjusted on TBS (TBS-FRAX®), and compared the proportion of patients with a high risk for major osteoporotic fracture (MOF)>20% according to FRAX® and TBS-FRAX®, and the proportion of subjects who should be treated according to current guidelines. Four hundred and thirteen patients were included for a non vertebral fracture (84.5% women, mean age of 73.9±11.7years), Two hundred and eight patients (50.4%) had osteoporosis (T≤-2.5 at least one site) and the mean value of TBS was 1.206 (±0.111). The proportion of patients with a risk of MOF≥20% before the fracture was similar with FRAX® and TBS-FRAX® (24.7% vs 25.4%). The proportion of patients identified with a risk of MOF above the threshold value of therapeutic intervention was higher using TBS-FRAX® than FRAX® for the age categories of 60-70years (38.3% vs 30.9%, p=0.01) and 70-80years (31.2% vs. 26.6%, p=0.04). This study showed that the proportion of patients at high risk of fracture is similar using FRAX® and FRAX® adjusted on TBS in patients hospitalized for a non vertebral fracture in a FLS.

Low-trauma fractures without osteoporosis

In clinical practice, areal bone mineral density (aBMD) is usually measured using dual-energy X-ray absorptiometry (DXA) to assess bone status in patients with or without osteoporotic fracture. As BMD has a Gaussian distribution, it is difficult to define a cutoff for osteoporosis diagnosis. Based on epidemiological considerations, WHO defined a DXA-based osteoporosis diagnosis with a T-score <-2.5. However, the majority of individuals who have low-trauma fractures do not have osteoporosis with DXA (i.e., T-score <-2.5), and some of them have no decreased BMD at all. Some medical conditions (spondyloarthropathies, chronic kidney disease and mineral bone disorder, diabetes, obesity) or drugs (glucocorticoids, aromatase inhibitors) are more prone to cause fractures with subnormal BMD. In the situation of fragility fractures with subnormal or normal BMD, clinicians face a difficulty as almost all the pharmacologic treatments have proved their efficacy in patients with low BMD. However, some data are available in post hoc analyses in patients with T score >-2. Overall, in patients with a previous fragility fracture (especially vertebra or hip), treatments appear to be effective. Thus, the authors recommend treating some patients with a major fragility fracture even if areal BMD T score is above -2.5.

Imminent fracture risk

The clinical significance of osteoporosis is in the occurrence of fractures and re-fractures. The main risk factor of sustaining a fracture is a previous one, but a recent fracture is a better fracture risk factor than fracture history. The role of the recency of fracture has been shown for both vertebral and non-vertebral fracture risk. This imminent risk is explained by both bone-related factors (underlying osteoporosis) and fall-related factors (including those related to postfracture care). Such a short-term increased risk has been shown also in patients initiating corticosteroids and in frail osteoporotic subjects with central nervous system (CNS) diseases or drugs targeting CNS, and thus a high risk of falls. Patients with an imminent (i.e. 2 years) risk of fracture or refracture should be identified in priority in order to receive an immediate treatment and a program of fall prevention.

EULAR/EFORT recommendations for management of patients older than 50 years with a fragility fracture and prevention of subsequent fractures

The European League Against Rheumatism (EULAR) and the European Federation of National Associations of Orthopaedics and Traumatology (EFORT) have recognised the importance of optimal acute care for the patients aged 50 years and over with a recent fragility fracture and the prevention of subsequent fractures in high-risk patients, which can be facilitated by close collaboration between orthopaedic surgeons and rheumatologists or other metabolic bone experts. Therefore, the aim was to establish for the first time collaborative recommendations for these patients. According to the EULAR standard operating procedures for the elaboration and implementation of evidence-based recommendations, 7 rheumatologists, a geriatrician and 10 orthopaedic surgeons met twice under the leadership of 2 convenors, a senior advisor, a clinical epidemiologist and 3 research fellows. After defining the content and procedures of the task force, 10 research questions were formulated, a comprehensive and systematic literature search was performed and the results were presented to the entire committee. 10 recommendations were formulated based on evidence from the literature and after discussion and consensus building in the group. The recommendations included appropriate medical and surgical perioperative care, which requires, especially in the elderly, a multidisciplinary approach including orthogeriatric care. A coordinator should setup a process for the systematic investigations for future fracture risk in all elderly patients with a recent fracture. High-risk patients should have appropriate non-pharmacological and pharmacological treatment to decrease the risk of subsequent fracture.

Can Chlamydia abortus be transmitted by embryo transfer in goats?

The objectives of this study were to determine (i) whether Chlamydia abortus would adhere to or penetrate the intact zona pellucida (ZP-intact) of early in vivo-derived caprine embryos, after in vitro infection; and (ii) the efficacy of the International Embryo Transfer Society (IETS) washing protocol for bovine embryos. Fifty-two ZP-intact embryos (8-16 cells), obtained from 14 donors were used in this experiment. The embryos were randomly divided into 12 batches. Nine batches (ZP-intact) of five embryos were incubated in a medium containing 4 × 10(7)Chlamydia/mL of AB7 strain. After incubation for 18 hours at 37 °C in an atmosphere of 5% CO2, the embryos were washed in batches in 10 successive baths of a phosphate buffer saline and 5% fetal calf serum solution in accordance with IETS guidelines. In parallel, three batches of ZP-intact embryos were used as controls by being subjected to similar procedures but without exposure to C. abortus. The 10 wash baths were collected separately and centrifuged for 1 hour at 13,000 × g. The washed embryos and the pellets of the 10 centrifuged wash baths were frozen at -20 °C before examination for evidence of C. abortus using polymerase chain reaction. C. abortus DNA was found in all of the infected batches of ZP-intact embryos (9/9) after 10 successive washes. It was also detected in the 10th wash fluid for seven batches of embryos, whereas for the two other batches, the last positive wash bath was the eighth and the ninth, respectively. In contrast, none of the embryos or their washing fluids in the control batches were DNA positive. These results report that C. abortus adheres to and/or penetrates the ZP of in vivo caprine embryos after in vitro infection, and that the standard washing protocol recommended by the IETS for bovine embryos, failed to remove it. The persistence of these bacteria after washing makes the embryo a potential means of transmission of the bacterium during embryo transfer from infected donor goats to healthy recipients and/or their offspring. Nevertheless, the detection of C. abortus DNA by polymerase chain reaction does not prove that the bacteria found was infectious. Further studies are required to investigate whether enzymatic and/or antibiotic treatment of caprine embryos infected by C. abortus would eliminate the bacteria from the ZP.

Absence of recognition of low alkaline phosphatase level in a tertiary care hospital

SUMMARY

Low serum total alkaline phosphatase level (ALP), the hallmark for hypophosphatasia (HPP), must be recognized to provide appropriate care of the patients and to avoid antiresorptive treatment. The prevalence of persistent low ALP in a clinical setting is 0.13% and the recognition is very low (3%).

INTRODUCTION

A low serum total alkaline phosphatase level is the hallmark for the diagnosis of hypophosphatasia. Although very rare, HPP must be recognized to provide appropriate treatment of non-union fractures and to avoid potentially harmful drugs, such as antiresorptive treatments. The aim of this study was to assess the recognition of persistent low ALP in a tertiary care hospital.

METHODS

Between the 1st of January and the 31st of December 2013, 48,755 patients had ALP assessment in the Biochemistry Department of our hospital. Sixty-eight patients had all serum ALP values persistently below 40 IU/l. Among them, six had potential causes of secondary hypophosphatasia. We consulted the summary discharges of the 62 patients in order to check for the notation of low ALP. Patients from the departments of rheumatology and internal medicine were contacted to fulfill a questionnaire about clinical manifestations potentially related to HPP.

RESULTS

0.13% of hospitalized patients had persistently low value. They were 46.5 ± 17.7 years old, and 73% were females. The low ALP value was notified in the discharge summary for two patients (3%), without any comment. Twenty-four patients (46 + /-16 years old) were contacted. Eight patients had fractures; two had a diagnosis of rickets in the childhood; two had symptomatic chondrocalcinosis. Nine had dental abnormalities. Three were receiving a bisphosphonate; two of them had a fracture while being treated with bisphosphonate.

CONCLUSION

Our study shows that low ALP is not recognized in a clinical setting in adults hospitalized in a tertiary care hospital.

Comparison of methods for the fabrication and the characterization of polymer self-assemblies: what are the important parameters?

The ability to self-assemble was evaluated for a large variety of amphiphilic block copolymers, including poly(ethyleneoxide-b-ε-caprolactone), poly(ethyleneoxide-b-d,l-lactide), poly(ethyleneoxide-b-styrene), poly(ethyleneoxide-b-butadiene) and poly(ethyleneoxide-b-methylmethacrylate). Different methods of formation are discussed, such as cosolvent addition, film hydration or electroformation. The influence of experimental parameters and macromolecular structures on the size and morphology of the final self-assembled structures is investigated and critically compared with the literature. The same process is carried out regarding the characterization of these structures. This analysis demonstrates the great care that should be taken when dealing with such polymeric assemblies. If the morphology of such assemblies can be predicted to some extent by macromolecular parameters like the hydrophilic/hydrophobic balance, those parameters cannot be considered as universal. In addition, external experimental parameters (methods of preparation, use of co-solvent, …) appeared as critical key parameters to obtain a good control over the final structure of such objects, which are very often not at thermodynamic equilibrium but kinetically frozen. A principal component analysis is also proposed, in order to examine the important parameters for forming the self-assemblies. Here again, the hydrophilic/hydrophobic fraction is identified as an important parameter.

Sagittal balance of the spine in patients with osteoporotic vertebral fractures

This study aims to compare the sagittal global spinal balance of patients consulting for osteoporosis, aged above 50 years with and without osteoporotic vertebral fractures (VFs). Global spinal balance is abnormal even in subjects without VFs. VFs and age are determinants of sagittal global balance; however, pelvic parameters play a role in compensatory mechanisms.

INTRODUCTION

This study aims to compare the spine curvatures, pelvic parameters, and the sagittal global spinal balance of patients aged above 50 years with and without osteoporotic vertebral fractures.

METHODS

Two hundred patients (95 % women) aged 68.3 ± 9.5 years underwent full skeleton radiographs in the standing position, by EOS®, a low dose biplane X-ray imaging system. VFs were evaluated according to Genant's classification. Spinal (thoracic and lumbar Cobb's indices, thoracic and lumbar tilts) and pelvic (pelvic tilt, sacral slope, and pelvic incidence) parameters were measured. Sagittal spinal balance was measured using the C7 plumb line and the spinosacral angle (SSA). We compared these parameters in patients with and without vertebral fracture and assessed the determinants of abnormal sagittal spinal balance.

RESULTS

Sixty-nine patients had at least one VF. The sagittal spinal balance was significantly altered in patients with at least one VF, and there was an effect of the number and severity of VFs on parameters. Discriminative value for identification of patients with at least one VF, assessed by Area Under the Curves (AUCs) was 0.652 and 0.706 for C7 plumbline and SSA, respectively. Using multivariate analysis, parameters significantly associated with abnormal spinal balance (SSA) were the presence of at least one VF (OR = 4.96, P < 0.0001), age (OR = 1.07, P = 0.0006), and high pelvic incidence as a protective factor (OR = 0.93, P < 0.0001).

CONCLUSIONS

Global spinal balance is abnormal in subjects consulting for osteoporosis, even in subjects without VFs. VFs and age are determinants of abnormal sagittal global balance; however, pelvic parameters play a role in compensatory mechanisms.

[Post-menopausal osteoporosis: Up-to-date]

Patients with a high risk of fragility fractures, and those with recent fractures, must receive the highest priority for anti-osteoporotic treatment, because of the consequences of some of these fractures (hip, vertebrae, pelvis, humerus). Both non pharmacological and pharmacological treatments must be used. The duration of the treatment is based on the assessment of fracture risk.

The effect of 8 or 5 years of denosumab treatment in postmenopausal women with osteoporosis: results from the FREEDOM Extension study

The FREEDOM study and its Extension provide long-term information about the effects of denosumab for the treatment of postmenopausal osteoporosis. Treatment for up to 8 years was associated with persistent reduction of bone turnover, continued increases in bone mineral density, low fracture incidence, and a favorable benefit/risk profile.

INTRODUCTION

This study aims to report the results through year 5 of the FREEDOM Extension study, representing up to 8 years of continued denosumab treatment in postmenopausal women with osteoporosis.

METHODS

Women who completed the 3-year FREEDOM study were eligible to enter the 7-year open-label FREEDOM Extension in which all participants are scheduled to receive denosumab, since placebo assignment was discontinued for ethical reasons. A total of 4550 women enrolled in the Extension (2343 long-term; 2207 cross-over). In this analysis, women in the long-term and cross-over groups received denosumab for up to 8 and 5 years, respectively.

RESULTS

Throughout the Extension, sustained reduction of bone turnover markers (BTMs) was observed in both groups. In the long-term group, mean bone mineral density (BMD) continued to increase significantly at each time point measured, for cumulative 8-year gains of 18.4 and 8.3 % at the lumbar spine and total hip, respectively. In the cross-over group, mean BMD increased significantly from the Extension baseline for 5-year cumulative gains of 13.1 and 6.2 % at the lumbar spine and total hip, respectively. The yearly incidence of new vertebral and nonvertebral fractures remained low in both groups. The incidence of adverse and serious adverse events did not increase over time. Through Extension year 5, eight events of osteonecrosis of the jaw and two events of atypical femoral fracture were confirmed.

CONCLUSIONS

Denosumab treatment for up to 8 years was associated with persistent reductions of BTMs, continued BMD gains, low fracture incidence, and a consistent safety profile.

Diagnosis of vertebral fractures using a low-dose biplanar imaging system

Vertebral fractures (VFs) are independent risk factors for new fractures. However, spine radiographs cannot be used as a screening method. EOS® has a good diagnostic value for the diagnosis of VF with a better legibility of upper thoracic spine and a higher concordance between readers compared to vertebral fracture assessment (VFA).

INTRODUCTION

Vertebral fractures (VFs) are risk factors for new fractures. However, spine radiographs cannot be used as a screening method for both cost and radiation concerns. EOS® X-ray imaging system which allows the acquisition of biplane images in an upright weight-bearing position with low radiation dose was used. The objective of this study was to compare EOS® to VFA for the diagnosis of VF.

METHODS

We conducted a cross-sectional study in subjects aged above 50 years with indication for spine imaging. EOS® and VFA of the spine were performed the same day. Sensitivity (Se), specificity (Sp), negative predictive value (NPV), and the interobserver precision of EOS® were compared to VFA for the diagnosis of VF.

RESULTS

Two hundred patients (mean age 66.2 years) were included. At the vertebral level, 2.4 and 3.6 % of vertebrae were not legible using EOS® and VFA, respectively (p = 0.0007). The legibility of spine was significantly affected by scoliosis (odds ratio (OR) = 2.8, p < 0.0001, for EOS®, and OR = 1.8, p = 0.0041, for VFA). Sixty-six patients (33.0 %) and 69 (34.5 %) had at least one VF using VFA and EOS®, respectively. At patient level, Se, Sp, and NPV for the diagnosis of VF of EOS® were 79.7, 91.6, and 99 %, respectively. Concordance between both observers was very good for EOS® (kappa-score = 0.89), higher than for VFA (κ = 0.67).

CONCLUSIONS

This study shows that EOS® has a good diagnostic value for the diagnosis of VF with a better legibility of upper thoracic spine and a higher concordance between readers compared to VFA.