PTH treatment before cyclic joint loading improves cartilage health and attenuates load-induced osteoarthritis development in mice

Osteoarthritis (OA) treatment is limited by the lack of effective nonsurgical interventions to slow disease progression. Here, we examined the contributions of the subchondral bone properties to OA development. We used parathyroid hormone (PTH) to modulate bone mass before OA initiation and alendronate (ALN) to inhibit bone remodeling during OA progression. We examined the spatiotemporal progression of joint damage by combining histopathological and transcriptomic analyses across joint tissues. The additive effect of PTH pretreatment before OA initiation and ALN treatment during OA progression most effectively attenuated load-induced OA pathology. Individually, PTH directly improved cartilage health and slowed the development of cartilage damage, whereas ALN primarily attenuated subchondral bone changes associated with OA progression. Joint damage reflected early transcriptomic changes. With both treatments, the structural changes were associated with early modulation of immunoregulation and immunoresponse pathways that may contribute to disease mechanisms. Overall, our results demonstrate the potential of subchondral bone-modifying therapies to slow the progression of OA.

Single dose thermoresponsive dexamethasone prodrug completely mitigates joint pain for 15 weeks in a murine model of osteoarthritis

In this study, we aimed to assess the analgesic efficacy of a thermoresponsive polymeric dexamethasone (Dex) prodrug (ProGel-Dex) in a mouse model of osteoarthritis (OA). At 12 weeks post model establishment, the OA mice received a single intra-articular (IA) injection of ProGel-Dex, dose-equivalent Dex, or Saline. Comparing to Saline and Dex controls, ProGel-Dex provided complete and sustained pain relief for >15 weeks according to incapacitance tests. In vivo optical imaging confirmed the continuous presence of ProGel-Dex in joints for 15 weeks post-injection. According to micro-CT analysis, ProGel-Dex treated mice had significantly lower subchondral bone thickness and medial meniscus bone volume than Dex and Saline controls. Except for a transient delay of body weight increase and slightly lower endpoint liver and spleen weights, no other adverse effect was observed after ProGel-Dex treatment. These findings support ProGel-Dex's potential as a potent and safe analgesic candidate for management of OA pain.

Stochastic modeling of Dalbulus maidis, vector of maize diseases

We developed a simple linear stochastic model for Dalbulus maidis dependent exclusively on temperature, whose parameters were determined from published field and laboratory studies performed at different temperatures. This model takes into account the principal stages and events of the life cycle of this pest, which is vector of maize diseases. We implemented the effect of distributed delays or Linear Chain Trick (LCT) considering a fixed number of sub-stages for egg and nymph stages of Dalbulus maidis in order to accurately represent what is observed in nature. A sensitivity analysis allows us to observe that the speed of the dynamics is sensitive to changes in the development rates, but not to the longevity of each stage or the fecundity, which almost exclusively affect insect abundance. We used our model to study its predictive and explanatory capacity considering a published experiment as a case study. Although the simulation results show a behavior qualitatively equivalent to that observed in the experimental results it is not possible to explain accurately the magnitude, nor the times in which the maximum abundances of second-generation nymphs and adults are reached. Therefore, we evaluated three possible scenarios for the insect that allow us to glimpse some of the advantages of having a computational model in order to find out what processes, taken into account in the model, may explain the differences observed between published experimental results and model results. The three proposed scenarios, based on variations in the parameterized rates of the model, can satisfactorily explain the experimental observations. We observed that in order to better simulate the experimental results it is not necessary to modify fecundity or mortality rates. However, it is necessary to accelerate the average development rates of our model by 20 to 40 %, compatible with extreme values of the rates close to the upper edges of the confidence bands of our parameterization rate curves, according to insects with faster development rates already reported in literature.

Machine learning identification of thresholds to discriminate osteoarthritis and rheumatoid arthritis synovial inflammation

BACKGROUND

We sought to identify features that distinguish osteoarthritis (OA) and rheumatoid arthritis (RA) hematoxylin and eosin (H&E)-stained synovial tissue samples.

METHODS

We compared fourteen pathologist-scored histology features and computer vision-quantified cell density (147 OA and 60 RA patients) in H&E-stained synovial tissue samples from total knee replacement (TKR) explants. A random forest model was trained using disease state (OA vs RA) as a classifier and histology features and/or computer vision-quantified cell density as inputs.

RESULTS

Synovium from OA patients had increased mast cells and fibrosis (p < 0.001), while synovium from RA patients exhibited increased lymphocytic inflammation, lining hyperplasia, neutrophils, detritus, plasma cells, binucleate plasma cells, sub-lining giant cells, fibrin (all p < 0.001), Russell bodies (p = 0.019), and synovial lining giant cells (p = 0.003). Fourteen pathologist-scored features allowed for discrimination between OA and RA, producing a micro-averaged area under the receiver operating curve (micro-AUC) of 0.85±0.06. This discriminatory ability was comparable to that of computer vision cell density alone (micro-AUC = 0.87±0.04). Combining the pathologist scores with the cell density metric improved the discriminatory power of the model (micro-AUC = 0.92±0.06). The optimal cell density threshold to distinguish OA from RA synovium was 3400 cells/mm2, which yielded a sensitivity of 0.82 and specificity of 0.82.

CONCLUSIONS

H&E-stained images of TKR explant synovium can be correctly classified as OA or RA in 82% of samples. Cell density greater than 3400 cells/mm2 and the presence of mast cells and fibrosis are the most important features for making this distinction.

Parieto-Occipital Injury on Diffusion MRI Correlates with Poor Neurologic Outcome following Cardiac Arrest

BACKGROUND AND PURPOSE

MR imaging of the brain provides unbiased neuroanatomic evaluation of brain injury and is useful for neurologic prognostication following cardiac arrest. Regional analysis of diffusion imaging may provide additional prognostic value and help reveal the neuroanatomic underpinnings of coma recovery. The purpose of this study was to evaluate global, regional, and voxelwise differences in diffusion-weighted MR imaging signal in patients in a coma after cardiac arrest.

MATERIALS AND METHODS

We retrospectively analyzed diffusion MR imaging data from 81 subjects who were comatose for >48 hours following cardiac arrest. Poor outcome was defined as the inability to follow simple commands at any point during hospitalization. ADC differences between groups were evaluated across the whole brain, locally by using voxelwise analysis and regionally by using ROI-based principal component analysis.

RESULTS

Subjects with poor outcome had more severe brain injury as measured by lower average whole-brain ADC (740 [SD, 102] × 10-6 mm2/s versus 833 [SD, 23] × 10-6 mm2/s, P < .001) and larger average volumes of tissue with ADC below 650 × 10-6 mms/s (464 [SD, 469] mL versus 62 [SD, 51] mL, P < .001). Voxelwise analysis showed lower ADC in the bilateral parieto-occipital areas and perirolandic cortices for the poor outcome group. ROI-based principal component analysis showed an association between lower ADC in parieto-occipital regions and poor outcome.

CONCLUSIONS

Brain injury affecting the parieto-occipital region measured with quantitative ADC analysis was associated with poor outcomes after cardiac arrest. These results suggest that injury to specific brain regions may influence coma recovery.

Dynamic adsorption of diclofenac onto a magnetic nanocomposite in a continuous stirred-tank reactor

In this study, a waste-based magnetic activated carbon (MAC) was used for the first time in a continuous-flow stirred tank reactor (CSTR). The aim was to evaluate the dynamic removal of diclofenac (DCF) from water and wastewater. Firstly, the breakthrough curves corresponding to DCF adsorption from distilled water at different feed flow rates and doses of MAC were determined. After selecting the most favourable conditions, namely 0.18 h L^-1 flow rate and 400 mg L^-1 of MAC, the effect of different aqueous matrices was studied, with the breakthrough curves evidencing a performance decline in wastewater in comparison with distilled water. Finally, the exhausted MAC was magnetically recovered, regenerated by microwave-assisted heating and applied in two subsequent adsorption cycles. The regeneration studies pointed to a decrease of the specific surface area and an improvement of the magnetic retrievability of MAC. After the first regeneration step, just mild effects were observed in the dynamic adsorptive performance of MAC. However, after a second regeneration step, the performance declined ca. 50%. Overall, the results highlight the feasibility of producing waste-based magnetic composites that simultaneously combine high adsorption efficiency under dynamic operation in a CSTR, with easy retrievability and successful one-stage regeneration for further reutilization.

Adaptive immune responses in patients requiring revision after total knee arthroplasty

Dissatisfaction occurs in nearly 20% of patients after total knee arthroplasty (TKA); however, there remains only limited understanding of the biologic mechanisms that may contribute to suboptimal postoperative outcomes requiring revision surgery. Expansion of effector T and B cells, could promote an abnormal healing response via local or peripheral immune system mechanisms and contribute to inferior outcomes necessitating revision TKA. In this pilot study, we hypothesized that patients suffering from complications of arthrofibrosis or instability may exhibit differences in adaptive immune function. Patients (n = 31) undergoing revision TKA for an indication of arthrofibrosis or instability were prospectively enrolled. Whole blood and synovial fluid (SF) from the operative knee were collected at time of surgery. Peripheral blood mononuclear cells were isolated and analyzed by flow cytometry. Serum and SF were assessed for immunoglobulin levels by Luminex and antiphospholipid antibodies by enzyme-linked immunoassay. No significant differences were observed in peripheral blood T/B cell populations or serum immunoglobulins levels between groups. SF analysis demonstrated significant differences between the two groups, with higher levels of immunoglobulin G1 (IgG1) (p = 0.0184), IgG3 (p = 0.0084) and antiphosphatidyl serine IgG (p = 0.034) in arthrofibrosis relative to instability patients. Increased levels of both IgG subclasses and antiphospholipid antibodies in the SF suggest that intra-articular T-B cell interactions, potentially triggered by exposure to apoptotic components generated during post-op healing, could be functioning as a source of immune complexes that fuel fibrous tissue growth in arthrofibrotic patients.

Association of circulating gene expression signatures with stiffness following total knee arthroplasty for osteoarthritis: a pilot study

A subset of patients undergoing total knee arthroplasty (TKA) for knee osteoarthritis develop debilitating knee stiffness (reduced range of motion) for poorly understood reasons. Dysregulated inflammatory and immune responses to surgery correlate with reduced surgical outcomes, but the dysregulated gene signatures in patients with stiffness after TKA are poorly defined. As a consequence, we are limited in our ability to identify patients at risk of developing poor surgical outcomes and develop preventative approaches. In this pilot study we aimed to identify perioperative blood gene signatures in patients undergoing TKA for knee osteoarthritis and its association with early surgical outcomes, specifically knee range of motion. To do this, we integrated clinical outcomes collected at 6 weeks after surgery with transcriptomics analyses in blood samples collected immediately before surgery and at 24 h after surgery. We found that patients with stiffness at 6 weeks after surgery have a more variable and attenuated circulating gene expression response immediately after surgery. Our results suggest that patients with stiffness following TKA may have distinct gene expression signatures detectable in peripheral blood in the immediate postoperative period.

OP0223 DISTINGUISHING OSTEOARTHRITIS AND RHEUMATOID ARTHRITIS SYNOVIUM WITH MACHINE LEARNING USING AUTOMATED CELL DENSITY AND PATHOLOGIST SCORES

Background

Joint damage in the knee can be severe in both rheumatoid arthritis (RA) and osteoarthritis (OA) such that total knee replacement (TKR) is often the only management option. Pathological assessment of the extent or type of synovial tissue inflammation from joint explants or biopsies can be useful. However, an ongoing challenge in using semi-quantitative assessments of synovitis is the disagreement between human pathologist scores of the same sample. We previously developed and validated a computer vision algorithm to automatically count each cell nucleus in an H&E-stained synovial whole slide image and yield a value of cell density, defined as mean nuclei count per mm2 of tissue1.

Objectives

We sought to develop methods to distinguish OA from RA based on machine learning analysis of histologic features on H&E-stained synovial tissue samples.

Methods

We measured 14 pathologist-scored histology features (137 RA and 152 OA patients) and computer vision quantified cell density (60 RA and 147 OA patients) in H&E stained synovial tissue samples from total knee replacement arthroplasty explants. A random forest model was trained using disease state (OA vs RA) as classifier and histology features and/or cell density as inputs, and feature importance scores for the model were calculated.

Results

Synovium from patients with RA exhibited increased lymphocytic inflammation, lining hyperplasia, neutrophils, detritus, plasma cells, Russell bodies, binucleate plasma cells, sub-lining giant cells, synovial lining giant cells, and fibrin (all p<0.001), while synovium from patients with OA had increased mast cells and fibrosis (both p<0.001). Fourteen pathologist-scored features allowed for discrimination between RA and OA samples, producing a macro-averaged area under the receiver operating curve (AUC) of 0.85. This discriminatory ability was comparable to that of the computer vision score of cell density alone (AUC = 0.88). Combining the pathologist scores with the cell density metric improved the discriminatory power of the model (AUC = 0.91). The three most important features in this combined model were mast cells followed by cell density and fibrosis (Figure 1). AUC values for each individual feature are provided in Table 1. The optimal cell density threshold to distinguish RA from OA synovium was 3,400 cells per mm2, which yielded a sensitivity of 0.82 and specificity of 0.82.

Table 1.

Area under receiver operating characteristic curves (AUC) of the synovial features in distinguishing RA and OA patients

FeatureAUCAutomated Cell Density0.88Fibrosis0.84Mast cells0.80Lining hyperplasia0.78Lymphocytic inflammation0.69Fibrin0.68Plasma cells0.66Detritus0.64Binucleate plasma cells0.60Neutrophils0.60Synovial giant cells0.58Sub-lining giant cells0.57Russell bodies0.56Germinal centers0.51Mucoid change0.50Figure 1.

Importance of synovial features in distinguishing RA and OA synovium

Feature importance scores for supervised machine learning model including all 14 pathology scores and the computer vision-generated cell density.

Conclusion

H&E-stained images of RA and OA TKR explant synovium are distinct. We identified cell density, mast cells and fibrosis as the three most important features for making this distinction, with RA being characterized by increased cell density, low mast cells, and low fibrosis. Cell density greater than 3400 per mm2 of tissue yields a sensitivity of 0.82 and a specificity of 0.82 for distinguishing RA from OA. In the future, this can have clinical and research applications as this technique removes the requirement for subjective selection of a certain field of interest, is reproducible, and is scalable as it does not require technical expertise of a pathologist.

References

[1]Guan S, Mehta B…Orange DE. Rheumatoid Arthritis Synovial Inflammation Quantification Using Computer Vision. ACR Open Rheumatology. 2022 Jan 10;acr2.11381.

Acknowledgements

This work was supported by the C. Ronald MacKenzie Young Scientist Endowment Award, the Leon Lowenstein Foundation, and the Kellen Scholar Award supported by the Anna Marie and Stephen Kellen Foundation Total Knee Improvement Program.

Disclosure of Interests

Bella Mehta Paid instructor for: Novartis, Susan Goodman Consultant of: UCB, Grant/research support from: Novartis, Edward DiCarlo: None declared, Deanna Jannat-Khah Shareholder of: AstraZeneca, Cytodyn, and Walgreens, J. Alex Gibbons: None declared, Miguel Otero Consultant of: Regeneron Pharmaceuticals, Grant/research support from: Tissue Genesis, Laura Donlin Speakers bureau: Stryker, Consultant of: Stryker, Grant/research support from: Karius, Inc, Tania Pannellini: None declared, William Robinson: None declared, Peter Sculco Consultant of: Intellijoint Surgical, DePuy Synthes, Lima Corporate, Zimmer Biomet, and EOS Imaging, Grant/research support from: Intellijoint Surgical and Zimmer Biomet, Mark Figgie Shareholder of: HS2, Mekanika, and Wishbone, Consultant of: Lima and Wishbone, Jose Rodriguez Consultant of: ConforMIS, Medacta, Exactech, Inc, and Smith & Nephew, Grant/research support from: DePuy, Exactech, Inc, and Smith & Nephew, Jessica Kirschmann: None declared, James Thompson: None declared, David Slater: None declared, Damon Frezza: None declared, Zhenxing Xu: None declared, Fei Wang: None declared, Dana Orange: None declared

Targeted transcriptomic analyses of RNA isolated from formalin-fixed and paraffin-embedded human menisci

Formalin-fixed and paraffin-embedded (FFPE) biospecimens are a valuable and widely-available resource for diagnostic and research applications. With biobanks of tissue samples available in many institutions, FFPE tissues could prove to be a valuable resource for translational orthopaedic research. The purpose of this study was to characterize the molecular profiles and degree of histologic degeneration on archival fragments of FFPE human menisci obtained during arthroscopic partial meniscectomy. We used FFPE menisci for multiplexed gene expression analysis using the NanoString nCounter® platform, and for histological assessment using a quantitative scoring system. In total, 17 archival specimens were utilized for integrated histologic and molecular analyses. The median patient age was 22 years (range: 14-62). We found that the genes with the highest normalized counts were those typically expressed in meniscal fibrocartilage. Gene expression differences were identified in patient cohorts based on age (≤40 years), including genes associated with the extracellular matrix and tissue repair. The majority of samples showed mild to moderate histologic degeneration. Based on these data, we conclude that FFPE human menisci can be effectively utilized for molecular evaluation following a storage time as long as 11 years. Statement of Clinical Significance: The integration of histological and transcriptomic analyses described in this study will be useful for future studies investigating the basis for biological classification of meniscus specimens in patients. Further exploration into the genes and pathways uncovered by this study may suggest targets for biomarker discovery and identify patients at greater risk for osteoarthritis once the meniscus is torn.

Informed consent in dentistry and medicine in Spain: Practical considerations and legality

BACKGROUND

The healthcare practice of dentistry, as well as medicine, is framed within a legal environment. Patients have the right to know all the information related to any action performed on them and dental or medical doctors are obliged to obtain their patient's prior written informed consent (IC) before undertaking any healthcare procedures.

MATERIAL AND METHODS

Here we reviewed the legality and jurisprudence in Spain regarding IC. We also used INFLESZ text readability analysis software to analyse a sample of official Spanish informed consent documents (ICDs) from different surgical and interventional procedures related to dentistry and oral cavity interventions.

RESULTS

It is a mistake to confound IC with ICDs. This error prevents physicians from considering the former as a care process in which the patient's authorisation signature is the last link in a chain formed, almost in its entirety, by the informative process and deliberation alongside the patient. Multiple factors can influence communication between practitioners and their patients. Importantly, treatment adherence is greater when patients feel involved and autonomous in shared decision-making and when the circumstances of their lives are adequately considered. We concluded that although the ICDs we analysed conformed to the requirements set out in international law, they were somewhat difficult to read according to the reading habits of the general Spanish population.

CONCLUSIONS

Knowledge about the legality of IC helps professionals to understand the problems that may arise from their non-compliance. This is because the omission or defective fulfilment of IC obligations is the origin of legal responsibility for medical practitioners. In this sense, to date, there have been more convictions for defective ICs than for malpractice. The information provided in ICs should include the risks, benefits, and treatment alternatives and must be tailored to the needs and capabilities of the patient to enable autonomous decision-making.

Computational pathology for musculoskeletal conditions using machine learning: advances, trends, and challenges

Histopathology is widely used to analyze clinical biopsy specimens and tissues from pre-clinical models of a variety of musculoskeletal conditions. Histological assessment relies on scoring systems that require expertise, time, and resources, which can lead to an analysis bottleneck. Recent advancements in digital imaging and image processing provide an opportunity to automate histological analyses by implementing advanced statistical models such as machine learning and deep learning, which would greatly benefit the musculoskeletal field. This review provides a high-level overview of machine learning applications, a general pipeline of tissue collection to model selection, and highlights the development of image analysis methods, including some machine learning applications, to solve musculoskeletal problems. We discuss the optimization steps for tissue processing, sectioning, staining, and imaging that are critical for the successful generalizability of an automated image analysis model. We also commenting on the considerations that should be taken into account during model selection and the considerable advances in the field of computer vision outside of histopathology, which can be leveraged for image analysis. Finally, we provide a historic perspective of the previously used histopathological image analysis applications for musculoskeletal diseases, and we contrast it with the advantages of implementing state-of-the-art computational pathology approaches. While some deep learning approaches have been used, there is a significant opportunity to expand the use of such approaches to solve musculoskeletal problems.

Histologic and molecular features in pathologic human menisci from knees with and without osteoarthritis

The objective of this study was to evaluate histologic and molecular features of meniscus degeneration in cohorts of patients with and without osteoarthritis (OA) of the knee. Menisci were obtained from patients undergoing total knee arthroplasty for OA (TKA) or arthroscopic partial meniscectomy (APM) for a torn knee meniscus. Degenerative meniscal tears were among the most common tear type in the APM group based on the pattern. Using an integrative workflow for molecular evaluation of formalin-fixed and paraffin-embedded tissues, human menisci underwent blinded histologic evaluation and NanoString gene expression analyses. Histology revealed increased proteoglycan content in TKA menisci compared to APM menisci, but otherwise no significant differences in the total pathology score or sub-scores between patients based on age or cohort. NanoString analyses revealed differential expression of genes primarily associated with the PI3K-AKT signaling pathway, cell cycle, and apoptosis. These data provide new insights into histological and molecular features of meniscus degeneration in patients with and without knee OA. Histologic assessment of menisci showed similar severity of overall degeneration between cohorts, but there were differences at the molecular level. The dysregulated pathways identified in this study could contribute to early-onset meniscus degeneration, or to a predisposition to meniscus tears and subsequent knee OA. Further studies that validate genes and pathways uncovered in this study will allow us to evaluate novel approaches to assess and treat meniscal degeneration.

Identification of biological risk factors for persistent postoperative pain after total knee arthroplasty

BACKGROUND

There is growing evidence that cytokines and adipokines are associated with osteoarthritis (OA) severity, progression, and severity of associated pain. However, the cytokine response to total knee arthroplasty (TKA) and its association with persistent postoperative pain is not well understood. This study aims to describe the perioperative systemic (plasma) and local (synovial fluid) cytokine profiles of patients who do and do not develop persistent pain after TKA.

METHODS

Patients undergoing primary unilateral TKA for end-stage OA were prospectively enrolled. Demographic and clinical data were gathered preoperatively and postoperatively. Synovial fluid was collected pre arthrotomy and plasma was collected at multiple time points before and after surgery. Persistent postoperative pain (PPP) was defined as Numerical Rating Score≥4 at 6 months. Cytokine levels were measured using the V-Plex Human Cytokine 30-Plex Panel (Mesoscale-Rockville, Maryland, USA). Cytokine levels were compared between PPP and minimal pain groups. Given that the study outcomes are exploratory, no adjustment was performed for multiple testing.

RESULTS

Incidence of persistent pain at 6 months post TKA was 15/162 (9.3%). Postoperative plasma levels of four cytokines were significantly different in patients who developed persistent postoperative pain: interleukin (IL)-10, IL-1β, vascular endothelial growth factor, and IL12/IL23p40. Significantly lower IL-10 levels in the prearthrotomy synovial fluid were associated with development of postoperative persistent pain.

CONCLUSIONS

This prospective cohort study described a distinct acute perioperative inflammatory response profile in patients who developed persistent post-TKA pain, characterized by significant differences in four cytokines over the first 2 postoperative days. These results support the growing evidence that the patient-specific biologic response to surgery may influence longer-term clinical outcomes after TKA.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT02626533.

Transcriptomic and epigenomic analyses uncovered Lrrc15 as a contributing factor to cartilage damage in osteoarthritis

In osteoarthritis (OA), articular chondrocytes display phenotypic and functional changes associated with epigenomic alterations. These changes contribute to the disease progression, which is characterized by dysregulated reparative processes and abnormal extracellular matrix remodeling leading to cartilage degradation. Recent studies using a murine model of posttraumatic OA highlighted the contribution of changes in DNA hydroxymethylation (5hmC) to OA progression. Here, we integrated transcriptomic and epigenomic analyses in cartilage after induction of OA to show that the structural progression of OA is accompanied by early transcriptomic and pronounced DNA methylation (5mC) changes in chondrocytes. These changes accumulate over time and are associated with recapitulation of developmental processes, including cartilage development, chondrocyte hypertrophy, and ossification. Our integrative analyses also uncovered that Lrrc15 is differentially methylated and expressed in OA cartilage, and that it may contribute to the functional and phenotypic alterations of chondrocytes, likely coordinating stress responses and dysregulated extracellular matrix remodeling.

Early inhibition of subchondral bone remodeling slows load-induced posttraumatic osteoarthritis development in mice

Posttraumatic osteoarthritis (PTOA) is associated with abnormal and increased subchondral bone remodeling. Inhibiting altered remodeling immediately following joint damage can slow PTOA progression. Clinically, however, inhibiting remodeling when significant joint damage is already present has minimal effects in slowing further disease progression. We sought to determine the treatment window following PTOA initiation in which inhibiting remodeling can attenuate progression of joint damage. We hypothesized that the most effective treatment would be to inhibit remodeling immediately after PTOA initiation. We used an animal model in which a single bout of mechanical loading was applied to the left tibia of 26-week-old male C57Bl/6 mice at a peak load of 9 N to initiate load-induced PTOA development. Following loading, we inhibited bone remodeling using daily alendronate (ALN) treatment administered either immediately or with 1 or 2 weeks' delay up to 3 or 6 weeks post-loading. A vehicle (VEH) treatment group controlled for daily injections. Cartilage and subchondral bone morphology and osteophyte development were analyzed and compared among treatment groups. Inhibiting remodeling using ALN immediately after load-induced PTOA initiation reduced cartilage degeneration, slowed osteophyte formation, and preserved subchondral bone volume compared to VEH treatment. Delaying the inhibition of bone remodeling at 1 or 2 weeks similarly attenuated cartilage degeneration at 6 weeks, but did not slow the development of osteoarthritis (OA)-related changes in the subchondral bone, including osteophyte formation and subchondral bone erosions. Immediate inhibition of subchondral bone remodeling was most effective in slowing PTOA progression across the entire joint, indicating that abnormal bone remodeling within the first week following PTOA initiation played a critical role in subsequent cartilage damage, subchondral bone changes, and overall joint degeneration. These results highlight the potential of anti-resorptive drugs as preemptive therapies for limiting PTOA development after joint injury, rather than as disease-modifying therapies after joint damage is established. © 2021 American Society for Bone and Mineral Research (ASBMR).

Immune and repair responses in joint tissues and lymph nodes after knee arthroplasty surgery in mice

The importance of a local tissue immune response in healing injured tissues such as skin and lung is well established. Little is known about whether sterile wounds elicit lymph node (LN) responses and inflammatory responses after injury of musculoskeletal tissues that are mechanically loaded during the repair response. We investigated LN and tissue immune responses in a tibial implant model of joint replacement surgery where wounded tissue is subjected to movement and mechanical loading postoperatively. Draining inguinal and iliac LNs expanded postoperatively, including increases in regulatory T cells and activation of a subset of T cells. Thus, tissue injury was actively sensed in secondary lymphoid organs, with the potential to activate adaptive immunity. Joint tissues exhibited three temporally distinct immune response components, including a novel interferon (IFN) response with activation of signal transducer and activator of transcription (STAT) and interferon regulatory factor (IRF) pathways. Fibrovascular tissue formation was not associated with a macrophage type 2 (M2) reparative immune response, but instead with delayed induction of interleukin-1 family (IL-1β, IL-33, IL-36), IL-17, and prostaglandin pathway genes concomitant with transforming growth factor (TGF)-β and growth factor signaling, fibroblast activation, and tissue formation. Tissue remodeling was associated with activity of the HOX antisense intergenic RNA (HOTAIR) pathway. These results provide insights into immune responses and regulation of tissue healing after knee arthroplasty that potentially can be used to develop therapeutic strategies to improve healing, prevent arthrofibrosis, and improve surgical outcomes. © 2021 American Society for Bone and Mineral Research (ASBMR).

In vitro responses to platelet-rich-plasma are associated with variable clinical outcomes in patients with knee osteoarthritis

Autologous blood-derived products such as platelet-rich plasma (PRP) are widely used to treat musculoskeletal conditions, including knee osteoarthritis (OA). However, the clinical outcomes after PRP administration are often variable, and there is limited information about the specific characteristics of PRP that impact bioactivity and clinical responses. In this study, we aimed to develop an integrative workflow to evaluate responses to PRP in vitro, and to assess if the in vitro responses to PRP are associated with the PRP composition and clinical outcomes in patients with knee OA. To do this, we used a coculture system of macrophages and fibroblasts paired with transcriptomic analyses to comprehensively characterize the modulation of inflammatory responses by PRP in vitro. Relying on patient-reported outcomes and achievement of minimal clinically important differences in OA patients receiving PRP injections, we identified responders and non-responders to the treatment. Comparisons of PRP from these patient groups allowed us to identify differences in the composition and in vitro activity of PRP. We believe that our integrative workflow may enable the development of targeted approaches that rely on PRP and other orthobiologics to treat musculoskeletal pathologies.

Obesity and load-induced posttraumatic osteoarthritis in the absence of fracture or surgical trauma

Osteoarthritis is increasingly viewed as a heterogeneous disease with multiple phenotypic subgroups. Obesity enhances joint degeneration in mouse models of posttraumatic osteoarthritis (PTOA). Most models of PTOA involve damage to surrounding tissues caused by surgery/fracture; it is unclear if obesity enhances cartilage degeneration in the absence of surgery/fracture. We used a nonsurgical animal model of load-induced PTOA to determine the effect of obesity on cartilage degeneration 2 weeks after loading. Cartilage degeneration was caused by a single bout of cyclic tibial loading at either a high or moderate load magnitude in adult male mice with severe obesity (C57Bl6/J + high-fat diet), mild obesity (toll-like receptor 5 deficient mouse [TLR5KO]), or normal adiposity (C57Bl6/J mice + normal diet and TLR5KO mice in which obesity was prevented by manipulation of the gut microbiome). Two weeks after loading, cartilage degeneration occurred in limbs loaded at a high magnitude, as determined by OARSI scores (P < .001). However, the severity of cartilage damage did not differ among groups. Osteophyte width and synovitis of loaded limbs did not differ among groups. Furthermore, obesity did not enhance cartilage damage in limbs evaluated 6 weeks after loading. Constituents of the gut microbiota differed among groups. Our findings suggest that, in the absence of surgery/fracture, obesity may not influence cartilage loss after a single mechanical insult, suggesting that either damage to surrounding tissues or repeated mechanical insult is necessary for obesity to influence cartilage degeneration. These findings further illustrate heterogeneity in PTOA phenotypes and complex interactions between mechanical/metabolic factors in cartilage loss.

Diagnostic change 2 years after a first episode of psychosis

Introduction

Psychiatric diagnoses are derived from expert opinion (1). Since no objective tests or markers are on the horizon, clinical psychiatry is anchored to “the patient’s altered experience, expression and existence, associated with suffering in self and/or others”(2). Many studies have examined diagnostic stability over time. In the last years investigators have been reporting prospective and retrospective consistencies of diagnoses between two time points, specially in first episodes of psychosis (3).

Objectives

To examine the prospective and retrospective stability of diagnostic categories 2 years after the first episode of psychosis

Methods

Data were examined from the First Episode Psychosis Program of Navarra (PEPsNA), a prospective observational study of a cohort of patients with first-episode psychosis in Navarra (Spain). Diagnosis was assigned using DSM-IV-TR at baseline and 24 months later. Diagnoses were divided into 5 categories: Affective psychosis, Schizophrenia spectrum psychosis, Schizoaffective disorder, acute psychosis and other diagnoses. Diagnostic change was examined using prospective and retrospective consistency

Results

A total of 78 first-episode psychosis cases with baseline and 24 months follow-up were identified. Table 1 shows the diagnosis movement matrix, and Figure 1 its graphical representation. Of cases, 71.8% (56/78) had the same baseline and 24 months follow-up diagnosis. Prospective and retrospective consistencies are shown in Table 2

Conclusions

The prospective and retrospective consistencies of Schizophrenia spectrum psychosis and acute psychosis were higher than others. Affective psychosis and Schizoaffective disorder show very variable consistencies

Impact of a first psychosis program in functional variables after two years of follow-up

Introduction

Early Intervention Services for Early-Phase Psychosis have shown efficacy and effectiveness (Correl C, JAMA). In Pamplona, Spain, there is an Early Intervention Program that has been providing multiprofesional assistance for First Psychotic Patients for the last two years.

Objectives

The aim of this study is to analize the longitudinal effects of the different interventions in several functional variables: GAF, Occupational State, CGI-CogS, QLS, Sofas and WHODAS II applied to 240 patients during two years of follow-up.

Methods

We apply an standard evaluation protocol to every patient at different times: premorbid, initial time and at months 6, 12, 18 and 24. We analyse the data with the SPSS statistical program to see the results in these variables.

Results

The GAF scale shows a decline during the first 6 months, but tends to reach and maintain the premorbid levels after a year of treatment. Regarding baseline, patients with normalized jobs or studies are 60.7%. This percentage persists during the next months of follow-up but decline at the 24^th month Both the Whodas and Sofas scale show improvement tends. The QLS results show a progresional improvement in every subcale during the whole time of follow-up.

Conclusions

The Early Intervention Services in Psychosis improve, not only psychopatological dimension but also functional areas, what is important for the whole recovery of First Psychotic Patients.

Impact of a first psychosis program in clinical variables after two years of follow-up

Introduction

Early Intervention Services for Early-Phase Psychosis have shown efficacy and effectiveness (Correl C, JAMA). In Pamplona, Spain, there is an Early Intervention Program that has been providing multiprofesional assistance for First Psychotic Patients for the last two years.

Objectives

The aim of this study is to analize the longitudinal effects of the different interventions in several clinical variables applied to 240 patients during two years of follow-up : CASH dimensions, substance abuse, antipsychotic type and dosage, remission rates, re-hospitalization rates and DSM 5 diagnoses.

Methods

We apply an standard evaluation protocol to every patient at different times: premorbid, initial time and at months 6, 12, 18 and 24. We analyse the data with the SPSS statistical program to see the results in these variables.

Results

The positive and disorganized dimensions show an evident decline during the treatment. The doses of antipsychotic drugs are low and tend to decline. 87% of patients are in monotherapy. The most frequent DSM 5 basal diagnosis is Brief Psychotic Episode, but during de follow-up the Diagnosis of Schizophrenia increase from 14,6% at baseline up to 46,2% at month 24. The remission rates are about 65% after 24 months.

Conclusions

Early Intervention Services improve psychopathological dimensions, prevents from re-hospitalization, allows the use of lower doses of Antipsychotic Drugs and improve the rates of remission. However, the diagnosis of Schizophrenia is high, so there is no evidence that these programs prevents from chronicity, but provide a better quality of life.

Mouse Models of Osteoarthritis: Surgical Model of Post-traumatic Osteoarthritis Induced by Destabilization of the Medial Meniscus

The surgical model of destabilization of the medial meniscus (DMM) has become a gold standard for studying the onset and progression of post-traumatic osteoarthritis (OA). The DMM model mimics clinical meniscal injury, a known predisposing factor for the development of human OA, and permits the study of structural and biological changes over the course of the disease. In addition, when applied to genetically modified or engineered mouse models, this surgical procedure permits dissection of the relative contribution of a given gene to OA initiation and/or progression. This chapter describes the requirements for the surgical induction of OA in mouse models, and provides guidelines and tools for the subsequent histological, immunohistochemical, and molecular analyses. Methods for the assessment of the contributions of selected genes in genetically modified strains are also provided.

Role of iRhoms 1 and 2 in Endochondral Ossification

Growth of the axial and appendicular skeleton depends on endochondral ossification, which is controlled by tightly regulated cell–cell interactions in the developing growth plates. Previous studies have uncovered an important role of a disintegrin and metalloprotease 17 (ADAM17) in the normal development of the mineralized zone of hypertrophic chondrocytes during endochondral ossification. ADAM17 regulates EGF-receptor signaling by cleaving EGFR-ligands such as TGFα from their membrane-anchored precursor. The activity of ADAM17 is controlled by two regulatory binding partners, the inactive Rhomboids 1 and 2 (iRhom1, 2), raising questions about their role in endochondral ossification. To address this question, we generated mice lacking iRhom2 (iR2−/−) with floxed alleles of iRhom1 that were specifically deleted in chondrocytes by Col2a1-Cre (iR1∆Ch). The resulting iR2−/−iR1∆Ch mice had retarded bone growth compared to iR2−/− mice, caused by a significantly expanded zone of hypertrophic mineralizing chondrocytes in the growth plate. Primary iR2−/−iR1∆Ch chondrocytes had strongly reduced shedding of TGFα and other ADAM17-dependent EGFR-ligands. The enlarged zone of mineralized hypertrophic chondrocytes in iR2−/−iR1∆Ch mice closely resembled the abnormal growth plate in A17∆Ch mice and was similar to growth plates in Tgfα−/− mice or mice with EGFR mutations. These data support a model in which iRhom1 and 2 regulate bone growth by controlling the ADAM17/TGFα/EGFR signaling axis during endochondral ossification.

Changes in DNA methylation accompany changes in gene expression during chondrocyte hypertrophic differentiation in vitro

During osteoarthritis (OA), articular chondrocytes undergo phenotypic changes that resemble developmental patterns characteristic of growth plate chondrocytes. These phenotypic alterations lead to a hypertrophy-like phenotype characterized by altered production of extracellular matrix constituents and increased collagenase activity, which, in turn, results in cartilage destruction in OA disease. Recent studies have shown that the phenotypic instability and dysregulated gene expression in OA are associated with changes in DNA methylation patterns. Subsequent efforts have aimed to identify changes in DNA methylation with functional impact in OA disease, to potentially uncover therapeutic targets. Here, we paired an in vitro 3D/pellet culture system that mimics chondrocyte hypertrophy with RNA sequencing (RNA-Seq) and enhanced reduced representation of bisulfite sequencing (ERRBS) to identify transcriptomic and epigenomic changes in murine primary articular chondrocytes undergoing hypertrophy-like differentiation. We identified hypertrophy-associated changes in DNA methylation patterns in vitro. Integration of RNA-Seq and ERRBS datasets identified associations between changes in methylation and gene expression. Our integrative analyses showed that hypertrophic differentiation of articular chondrocytes is accompanied by transcriptomic and epigenomic changes in vitro. We believe that our integrative approaches have the potential to uncover new targets for therapeutic intervention.

Compost Tea Reduces the Susceptibility of Pinus radiata to Fusarium circinatum in Nursery Production

Nutrition is one of the factors that most limits forestry plant growth; thus, current production in nurseries is based on conventional fertilization focused on enhancing vigor. However, an excessive intake of mineral nitrogen can cause morphological imbalances and the formation of more succulent tissues which, consequently, increase susceptibility to plant pathogens. Fusarium circinatum is the causal agent of pitch canker in plants of the Pinus genus, with Pinus radiata being the species most susceptible to this disease. This study compares the response of P. radiata seedlings to infection by F. circinatum as influenced by two fertilizers-conventional and aerated compost tea (ACT)-applied during the nursery phase. The potential of ACT against F. circinatum was first tested in vitro, where it was found to inhibit the pathogen's mycelial growth and conidial germination. In the greenhouse, infected plants fertilized with ACT exhibited less severe internal and external symptoms of pitch canker and lower levels of pathogen colonization of both stems and needles than with conventional fertilizer. An analysis of the hormone content and defense-related gene expression shows greater salicylic acid production and phenylalanine ammonium-lyase and chalcone synthase expression in ACT-fertilized pine. All of the parameters assessed are consistent in showing that biofertilization with ACT reduces the susceptibility of pine seedlings to the disease compared with conventional fertilization.

Labral calcification plays a key role in hip pain and symptoms in femoroacetabular impingement

BACKGROUND

Hip osteoarthritis (HOA) is the most common hip disorder and a major cause of disability in the adult population, with an estimated prevalence of end-stage disease and total hip replacement. Thus, the diagnosis, prevention, and treatment of the early stages of the disease in young adults are crucial to reduce the incidence of end-stage HOA. The purpose of this study was to determine whether (1) a relationship among the inflammatory status of labrum and synovium collected from patients with femoroacetabular impingement (FAI) would exist; and (2) to investigate the associations among the histopathological features of joint tissues, the pre-operative symptoms and the post-operative outcomes after arthroscopic surgery.

METHODS

Joint tissues from 21 patients undergoing hip arthroscopy for FAI were collected and their histological and immunohistochemical features were correlated with clinical parameters.

RESULTS

Synovial mononuclear cell infiltration was observed in 25% of FAI patients, inversely correlated with the hip disability and osteoarthritis outcome score (HOOS) pain and function subscales and with the absolute and relative change in total HOOS. All the labral samples showed some pattern of degeneration and 67% of the samples showed calcium deposits. The total labral score was associated with increased CD68 positive cells in the synovium. The presence of labral calcifications, along with the chondral damage worsened the HOOS post-op symptoms (adjusted R-square = 0.76 p = 0.0001).

CONCLUSIONS

Our study reveals a relationship between the histologic labral features, the synovial inflammation, and the cartilage condition at the time of FAI. The presence of labral calcifications, along with the cartilage damage and the synovitis negatively affects the post-operative outcomes in patients with FAI.

Identification of Inflammatory Mediators in Tendinopathy Using a Murine Subacromial Impingement Model

Subacromial impingement is associated with a spectrum of disorders-including rotator cuff disease-but their relationship is complex. We have established a novel murine model of subacromial impingement to study supraspinatus tendinopathy. The purpose of this study was to evaluate changes in gene expression in this murine shoulder impingement model to further elucidate the mechanisms underlying the development of tendinopathy. Twenty-eight C57BL/6 mice were used in this study. All mice underwent bilateral surgery with insertion of a small metal clip in the subacromial space or a sham procedure. The supraspinatus tendons underwent histological analyses, biomechanical testing, and RNA extraction for multiplex gene expression analysis (NanoString, Seattle, WA). Histology demonstrated increased cellularity and disorganized collagen fibers of the supraspinatus tendon in the clip impingement group. Mean load to failure (5.20 vs. 1.50 N, p < 0.001) and mean stiffness (4.95 vs. 1.47 N/mm, p < 0.001) were lower in the impingement group than the sham group. NanoString analyses revealed 111 differentially expressed genes (DEGs) between the impingement and sham groups. DEGs of interest included Mmp3 (expression ratio [ER]: 2.68, p = 0.002), Tgfb1 (ER: 1.76, p = 0.01), Col3a1 (ER: 1.66, p = 0.03), and Tgfbr2 (ER: 1.53, p = 0.01). Statement of clinical significance: We identified 111 DEGs that may contribute to the development of tendinopathy in this model. Further studies of these specific genes will allow identification of their roles in the initiation and regulation of tendon damage, and their potential to serve as novel therapeutic targets in the treatment of rotator cuff disease. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2575-2582, 2019.

Low-level cyclic tibial compression attenuates early osteoarthritis progression after joint injury in mice

OBJECTIVE

Mechanical loading and joint health have a unique relationship in osteoarthritis (OA) onset and progression. Although high load levels adversely affect cartilage health, exercise that involves low to moderate load levels can alleviate OA symptoms. We sought to isolate the beneficial effects of mechanical loading using controlled in vivo cyclic tibial compression. We hypothesized that low-level cyclic compression would attenuate post-traumatic OA symptoms induced by destabilization of the medial meniscus (DMM).

METHODS

10-week-old C57Bl/6J male mice underwent DMM surgery (n = 51). After a 5-day post-operative recovery period, we applied daily cyclic tibial compression to the operated limbs at low (1.0N or 2.0N) or moderate (4.5N) magnitudes for 2 or 6 weeks. At the completion of loading, we compared cartilage and peri-articular bone features of mice that underwent DMM and loading to mice that only underwent DMM.

RESULTS

Compared to DMM alone, low-level cyclic compression for 6 weeks attenuated DMM-induced cartilage degradation (OARSI score, P = 0.008, 95% confidence interval (CI): 0.093 to 0.949). Low-level loading attenuated DMM-induced osteophyte formation after 2 weeks (osteophyte size, P = 0.033, 95% CI: 3.27-114.45 μm), and moderate loading attenuated subchondral bone sclerosis after 6 weeks (tissue mineral density (TMD), P = 0.011, 95% CI: 6.32-70.60 mg HA/ccm) compared to limbs that only underwent DMM. Finally, loading had subtle beneficial effects on cartilage cellularity and aggrecanase activity after DMM.

CONCLUSION

Low-level cyclic compression is beneficial to joint health after an injury. Therefore, the progression of early OA may be attenuated by applying well controlled, low-level loading shortly following joint trauma.

Inducible knockout of CHUK/IKKα in adult chondrocytes reduces progression of cartilage degradation in a surgical model of osteoarthritis

CHUK/IKKα contributes to collagenase-driven extracellular matrix remodeling and chondrocyte hypertrophic differentiation in vitro, in a kinase-independent manner. These processes contribute to osteoarthritis (OA), where chondrocytes experience a phenotypic shift towards hypertrophy concomitant with abnormal matrix remodeling. Here we investigated the contribution of IKKα to OA in vivo. To this end, we induced specific IKKα knockout in adult chondrocytes in AcanCreER^T2/+; IKKα^f/f mice treated with tamoxifen (cKO). Vehicle-treated littermates were used as wild type controls (WT). At 12 weeks of age, WT and cKO mice were subjected to the destabilization of medial meniscus (DMM) model of post-traumatic OA. The cKO mice showed reduced cartilage degradation and collagenase activity and fewer hypertrophy-like features at 12 weeks after DMM. Interestingly, in spite of the protection from structural articular cartilage damage, the postnatal growth plates of IKKα cKO mice after DMM displayed abnormal architecture and composition associated with increased chondrocyte apoptosis, which were not as evident in the articular chondrocytes of the same animals. Together, our results provide evidence of a novel in vivo functional role for IKKα in cartilage degradation in post-traumatic OA, and also suggest intrinsic, cell-autonomous effects of IKKα in chondrocytes that control chondrocyte phenotype and impact on cell survival, matrix homeostasis, and remodeling.

Stochastic population model of Zea mays L

We propose a minimalist stochastic population model of maize, focused on the description of the maize vegetative stages (seedlings with different number of leaves) involved in the propagation of vector-borne diseases. This model was parameterized from laboratory and field experiments and from observational field studies for multiple hybrids and different weather and soil conditions, taking into account only temperature as input variable. We propose three different submodels to estimate the distribution of the Final Leaf Number N_FLN in the plants and to estimate the tassel initiation probability. The first submodel (submodel A), with a fixed N_FLN, is adaptable to any particular hybrid, the second and third submodels allow to simulate plants with an empirical N_FLN distribution according to bibliographic averages (submodel B) or according to a Poisson Process (submodel C). The three submodels are able to describe the temporal development of populations and events. A good agreement is observed between the development times predicted by the model and the values obtained from laboratory experiments at constant temperature, field experiments carried out in Brazil and Australia and observational studies performed in Argentina. This model may be improved and coupled to leaf growth models and leaf area estimation models to be able to estimate not only the temporal development of populations and events but also the temporal development of the leaf area by plant, which is believed to be related to the carrying capacity of maize specialists insects, vectors of maize diseases.

3-morpholinosydnonimine (SIN-1)-induced oxidative stress leads to necrosis in hypertrophic chondrocytes in vitro

Chondrocyte is targeted for disruption in Osteoarthritis (OA) and Kashin-Beck Disease (KBD), and chondrocyte death in cartilage may contribute to the progression of OA and KBD. Oxidative stress leads to increased risk for OA. Previous work in our laboratory implicates oxidative stress as a potential mediator in children with KBD. While these studies suggest a role for oxidative stress in the modulation of OA and KBD, the direct effects of reactive oxygen species/reactive nitrogen species (ROS/RNS) on the stability of this domain remain unclear. Here, we demonstrate that oxidative stress, as induced through treatment with 3-morpholinosydnonimine (SIN-1), a spontaneous ROS/RNS generator, decreased the cell viability in hypertrophic chondrocytes in a dose- and time- dependent manner. SIN-1 induced necrosis in hypertrophic chondrocytes, whereas triggered apoptosis in non-hypertrophic cells of non-differentiated ATDC5 cells and C28/I2 cells. Ultrastructural analysis of hypertrophic chondrocyte treated with SIN-1 revealed morphological changes, such as plasma membrane breakdown, generalized swelling of the cytoplasm and organelles, even to disappearance. Moreover, SIN-1 induced chondronecrosis in the deep zone of engineered cartilage tissue, such as cell-free vacancy and "red ghost" cells. Overall, we demonstrate for the first time that oxidative stress, as induced through exogenous ROS/RNS, leads to necrosis in hypertrophic chondrocytes. Oxidative stress-mediated necrotic cell death contributes to chondronecrosis in the deep zone of cartilage in both OA and KBD.

Phenotypic instability of chondrocytes in osteoarthritis: on a path to hypertrophy

Articular chondrocytes are quiescent, fully differentiated cells responsible for the homeostasis of adult articular cartilage by maintaining cellular survival functions and the fine-tuned balance between anabolic and catabolic functions. This balance requires phenotypic stability that is lost in osteoarthritis (OA), a disease that affects and involves all joint tissues and especially impacts articular cartilage structural integrity. In OA, articular chondrocytes respond to the accumulation of injurious biochemical and biomechanical insults by shifting toward a degradative and hypertrophy-like state, involving abnormal matrix production and increased aggrecanase and collagenase activities. Hypertrophy is a necessary, transient developmental stage in growth plate chondrocytes that culminates in bone formation; in OA, however, chondrocyte hypertrophy is catastrophic and it is believed to initiate and perpetuate a cascade of events that ultimately result in permanent cartilage damage. Emphasizing changes in DNA methylation status and alterations in NF-κB signaling in OA, this review summarizes the data from the literature highlighting the loss of phenotypic stability and the hypertrophic differentiation of OA chondrocytes as central contributing factors to OA pathogenesis.

Descriptive study of ultrasound images of the upper airway obtained after insertion of laryngeal mask

OBJECTIVE

To evaluate clinical usefulness of ultrasound images of the upper airway in order to check correct laryngeal mask placement.

MATERIAL AND METHODS

A prospective observational study was conducted on patients scheduled for abdominal surgery under general anaesthesia, in whom the patency of the upper airway was ensured using an Ambu^®AuraGain^TM laryngeal mask. An ultrasound scan was performed of the upper-airway in the cranio-caudal direction and with longitudinal scans in the anterior midline and parasagittal axis, in three moments: before, after inserting and after removing the mask. All recorded images were evaluated in a second time by a radiologist-expert in upper airway ultrasound. Subsequently, the ultrasound data were related to the clinical difficulty of the insertion and presence of air leaks.

RESULTS

Data was collected from 30 patients (20 females and 10 males) being operated on for abdominal hysterectomy (15), eventroplasty (6), uterine myomectomy (3), and umbilical (4) and inguinal herniorrhaphy (2). The blind insertion of the masks did not present difficulties in 24 (80%) patients. Air leakage was detected in 8 (26.7%) patients, which was moderate in 7 cases and severe in one of them. The ultrasound findings confirmed good mask placement in 22 (73.3%) patients. Anatomical airway changes after laryngeal mask extraction were only observed in 3 (12%) patients, all of them minor. There was a statistically significant association (P<.05) between difficulty in inserting the device and the level of air leakage.

CONCLUSIONS

Upper airway ultrasound is a useful diagnostic method to evaluate laryngeal mask placement. Laryngeal oedema was not observed after removal of the device.

Immunomodulatory activity of 2-deoxyguanosine nanoparticles in DNA vaccines

DNA vaccines induce protective immune responses against several pathogens and tumor cells, but strategies to improve their effectiveness are still under study. Only two adjuvants have been licensed by the FDA, which increases the needs for the discovery of novel adjuvants for HIV vaccines and other infectious diseases. In this regard, we study the immunomodulatory properties of 2-Deoxyguanosine-based nanoparticles (SHS) in DNA vaccines coding for HIV Gag (NL4-3 clone) and Vaccinia Virus Western Reserve (VVWR) A27 proteins. The sequence of A27L was codon optimized and linked to the Outer Domain-1 (OD1) of gp120 HIV-1 protein sequence serving as an additional molecular adjuvant. In this study, female Balb/c mice were immunized three times intramuscularly with plasmids (pGag and pOD1-A27L). Then, seven days after the last dose, cellular and humoral immunity were evaluated through ELISpot and ELISA assays. We found significantly higher frequencies of IFN-γ-producing cells in mouse immunized with pGag and pOD1-A27L co-formulated with SHS versus controls. We also found higher significant levels of IFN-γ over IL-4 in supernatant of splenocytes isolated from mice receiving pGag and pOD1-A27L combined with SHS. Moreover, administration of pOD1-A27L+SHS stimulated a significant higher production of total IgG in mice when compared to Naïve group. Here, we demonstrated that pGag and pOD1-A27L vaccines co-formulated with SHS nanoparticles successfully activate adaptive immunity through production of Th-1 cytokines and/or IgG antibodies. As this type of immunity is essential to clear many viral infections, these data support the evaluation of SHS nanoparticles as a novel adjuvant for DNA vaccines against multiple viral infectious agents.

Phlpp inhibitors block pain and cartilage degradation associated with osteoarthritis

Phlpp protein phosphatases are abnormally abundant within human osteoarthritic articular chondrocytes and may contribute to the development of osteoarthritis. Mice lacking Phlpp1 were previously shown to be resistant to post-traumatic osteoarthritis. Here a small molecule with therapeutic properties that inhibits Phlpp1 and Phlpp2 was tested for its ability to slow post-traumatic OA in mice and to stimulate anabolic pathways in human articular cartilage from OA joints. PTOA was induced in male C57Bl/6 mice by surgically destabilizing the meniscus. Seven weeks after surgery, mice received a single intra-articular injection of the Phlpp inhibitor NSC117079 or saline. Mechanical allodynia was measured with von Frey assays, mobility was tracked in an open field system, and cartilage damage was assessed histologically. A single intra-articular injection of the Phlpp inhibitor NSC117079 attenuated mechanical allodynia and slowed articular cartilage degradation in joints with a destabilized meniscus. Animals treated with the Phlpp inhibitor 7 weeks after injury maintained normal activity levels, while those in the control group traveled shorter distances and were less active 3 months after the joint injury. NSC117079 also increased production of cartilage extracellular matrix components (glycosaminoglycans and aggrecan) in over 90% of human articular cartilage explants from OA patients and increased phosphorylation of Phlpp1 substrates (AKT2, ERK1/2, and PKC) in human articular chondrocytes. Our results indicate that Phlpp inhibitor NSC117079 is a novel osteoarthritis disease modifying drug candidate that may have palliative affects. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1487-1497, 2018.

Elf3 Contributes to Cartilage Degradation in vivo in a Surgical Model of Post-Traumatic Osteoarthritis

The E-74 like factor 3 (ELF3) is a transcription factor induced by inflammatory factors in various cell types, including chondrocytes. ELF3 levels are elevated in human cartilage from patients with osteoarthritis (OA), and ELF3 contributes to the IL-1β-induced expression of genes encoding Mmp13, Nos2, and Ptgs2/Cox2 in chondrocytes in vitro. Here, we investigated the contribution of ELF3 to cartilage degradation in vivo, using a mouse model of OA. To this end, we generated mouse strains with cartilage-specific Elf3 knockout (Col2Cre:Elf3^f/f) and Comp-driven Tet-off-inducible Elf3 overexpression (TRE-Elf3:Comp-tTA). To evaluate the contribution of ELF3 to OA, we induced OA in 12-week-old Col2Cre:Elf3^f/f and 6-month-old TRE-Elf3:Comp-tTA male mice using the destabilization of the medial meniscus (DMM) model. The chondrocyte-specific deletion of Elf3 led to decreased levels of IL-1β- and DMM-induced Mmp13 and Nos2 mRNA in vitro and in vivo, respectively. Histological grading showed attenuation of cartilage loss in Elf3 knockout mice compared to wild type (WT) littermates at 8 and 12 weeks following DMM surgery that correlated with reduced collagenase activity. Accordingly, Elf3 overexpression led to increased cartilage degradation post-surgery compared to WT counterparts. Our results provide evidence that ELF3 is a central contributing factor for cartilage degradation in post-traumatic OA in vivo.

Characterization of the immune response elicited by the vaccinia virus L3 protein delivered as naked DNA

Poxviruses are complex dsDNA viruses with over 200 genes, many of them with unknown role in the stimulation of immune responses. Among these, the vaccinia virus (VACV) L3L ORF encodes an essential protein for the transcription of the VACV early genes. To the best of our knowledge, the immune response elicited by L3 has not been characterized. In this regard, our data describes a DNA L3-coding plasmid (pL3L) that stimulates both, humoral- and cell-mediated immune responses in a mouse model. Cell-mediated immune responses were measured by IFN-γ and IL-4 ELISPOT assays. We performed CD8⁺ cells depletion and flow cytometry analysis to account for the contribution of cytotoxic T lymphocytes in the IFN-γ production. Moreover, results from ELISPOT were confirmed by measuring the concentration of IL-4 and IFN-γ in supernatant of antigen-stimulated splenocytes by cytokine ELISA. Additionally, dominant antigenic regions of L3 protein were identified by epitope mapping analysis. Humoral immune responses were assessed by ELISA. Specifically, the production of total IgG, IgG1 (TH-2) and IgG2a (TH-1) were determined one week after the final immunization. Our ELISPOT data shows pL3L-immunized animals to produce significantly higher frequencies of IFN-γ Spot-Forming Cells (SFC) versus controls. IL-4 levels remained unchanged in all three groups, demonstrating the increase in antigen-specific IFN-γ releasing cells. Flow cytometry assay results showed that CD8⁺ T cells are a major contributor to the production of IFN-γ. Moreover, our formulation enhances the production of total IgG, predominantly IgG2a isotype. Immunization with pL3L promotes a robust cytotoxic immune response, crucial against viral pathogens. In addition, our vaccine candidate promotes an increase in IgG levels, especially IgG2a (TH-1 type). Our data encourages further studies of L3 as a novel antigen in vaccine development against poxviruses.

E74-Like Factor (ELF3) and Leptin, a Novel Loop Between Obesity and Inflammation Perpetuating a Pro-Catabolic State in Cartilage

BACKGROUND/AIMS

The E74-like factor 3 (ELF3) is an inflammatory mediator that participates in cartilage destruction in osteoarthritis. Leptin and other adipokines negatively impact articular cartilage, triggering catabolic and inflammatory responses in chondrocytes. Here, we investigated whether leptin induces ELF3 expression in chondrocytes and the signaling pathway involved in this process.

METHODS

We determined mRNA and protein levels of ELF3 by RT-qPCR and Western blotting using cultured human primary chondrocytes and the human T/C-28a2 chondrocyte cell line. Further, we measured luciferase activities of different reporter constructs, and we assessed the contribution of leptin to the induction of ELF3 mRNA by knocking down hLEPR gene expression using siRNA technology.

RESULTS

Leptin synergizes with IL-1β in inducing ELF3 expression in chondrocytes. We also found that PI3K, p38, and JAK2 signaling pathways are at play in the leptin-driven induction of ELF3. Moreover, we confirm the participation of NFΚB in the leptin/IL-1β synergistic induction of ELF3.

CONCLUSION

Here we show, for the first time, the regulation of ELF3 expression by leptin, suggesting that this transcription factor likely mediates the inflammatory responses triggered by leptin in articular chondrocytes.

Collagen XI mutation lowers susceptibility to load-induced cartilage damage in mice

Interactions among risk factors for osteoarthritis (OA) are not well understood. We investigated the combined impact of two prevalent risk factors: mechanical loading and genetically abnormal cartilage tissue properties. We used cyclic tibial compression to simulate mechanical loading in the cho/+ (Col11a1 haploinsufficient) mouse, which has abnormal collagen fibrils in cartilage due to a point mutation in the Col11a1 gene. We hypothesized that the mutant collagen would not alter phenotypic bone properties and that cho/+ mice, which develop early onset OA, would develop enhanced load-induced cartilage damage compared to their littermates. To test our hypotheses, we applied cyclic compression to the left tibiae of 6-month-old cho/+ male mice and wild-type (WT) littermates for 1, 2, and 6 weeks at moderate (4.5 N) and high (9.0 N) peak load magnitudes. We then characterized load-induced cartilage and bone changes by histology, microcomputed tomography, and immunohistochemistry. Prior to loading, cho/+ mice had less dense, thinner cortical bone compared to WT littermates. In addition, in loaded and non-loaded limbs, cho/+ mice had thicker cartilage. With high loads, cho/+ mice experienced less load-induced cartilage damage at all time points and displayed decreased matrix metalloproteinase (MMP)-13 levels compared to WT littermates. The thinner, less dense cortical bone and thicker cartilage were unexpected and may have contributed to the reduced severity of load-induced cartilage damage in cho/+ mice. Furthermore, the spontaneous proteoglycan loss resulting from the mutant collagen XI was not additive to cartilage damage from mechanical loading, suggesting that these risk factors act through independent pathways. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:711-720, 2018.

Paracetamol and salicylic acid removal from contaminated water by microalgae

The biomass growth, pharmaceutical removal and light conversion efficiency of Chlorella sorokiniana under the presence of paracetamol (PC) and salicylic acid (SaC) were assessed and compared at two different concentrations of these pharmaceuticals (I: 25 mg l^-1, II: 250 mg l^-1). Microalgae were resistant to these concentrations and, moreover, their growth was significantly stimulated (p ≤ 0.05) under these drugs (biomass concentration increased above 33% PCI, 35% SaCI, 13% PCII and 45% SaCII, as compared with the respective positive controls). At the steady state of the semicontinuous culture, C. sorokiniana showed removal efficiencies above 41% and 69% for PCI and PCII, respectively; and above 93% and 98% for SaCI and SaCII, respectively. Under an irradiance of 370 μE m^-2 s^-1, higher quantum yields were reached by microalgae under the presence of drugs, either at dose I or II, than by the respective positive controls. These results point to C. sorokiniana as a robust strain for the bioremediation of paracetamol and salicylic acid concentrated wastewaters.

DNA methylation of the RUNX2 P1 promoter mediates MMP13 transcription in chondrocytes

The Runt-related transcription factor 2 (RUNX2) is critical for bone formation as well as chondrocyte maturation. Matrix metalloproteinase (MMP)-13 is a major contributor to cartilage degradation in osteoarthritis (OA). We and others have shown that the abnormal MMP13 gene expression in OA chondrocytes is controlled by changes in the DNA methylation status of specific CpG sites of the proximal promoter, as well as by the actions of different transactivators, including RUNX2. The present study aimed to determine the influence of the methylation status of specific CpG sites in the RUNX2 promoter on RUNX2-driven MMP13 gene expression in OA chondrocytes. We observed a significant correlation between MMP13 mRNA levels and RUNX2 gene expression in human OA chondrocytes. RUNX2 overexpression enhanced MMP13 promoter activity, independent of the MMP13 promoter methylation status. A significant negative correlation was observed between RUNX2 mRNA levels in OA chondrocytes and the percentage methylation of the CpG sites in the RUNX2 P1 promoter. Accordingly, the activity of the wild type RUNX2 promoter was decreased upon methylation treatment in vitro. We conclude that RUNX2 gene transcription is regulated by the methylation status of specific CpG sites in the promoter and may determine RUNX2 availability in OA cartilage for transactivation of genes such as MMP13.

Vaccination with a codon-optimized A27L-containing plasmid decreases virus replication and dissemination after vaccinia virus challenge

Smallpox is a disease caused by Variola virus (VARV). Although eradicated by WHO in 1980, the threat of using VARV on a bioterror attack has increased. The current smallpox vaccine ACAM2000, which consists of live vaccinia virus (VACV), causes complications in individuals with a compromised immune system or with previously reported skin diseases. Thus, a safer and efficacious vaccine needs to be developed. Previously, we reported that our virus-free DNA vaccine formulation, a pVAX1 plasmid encoding codon-optimized VACV A27L gene (pA27LOPT) with and without Imiquimod adjuvant, stimulates A27L-specific production of IFN-γ and increases humoral immunity 7days post-vaccination. Here, we investigated the immune response of our novel vaccine by measuring the frequency of splenocytes producing IFN-γ by ELISPOT, the TH1 and TH2 cytokine profiles, and humoral immune responses two weeks post-vaccination, when animals were challenged with VACV. In all assays, the A27-based DNA vaccine conferred protective immune responses. Specifically, two weeks after vaccination, mice were challenged intranasally with vaccinia virus, and viral titers in mouse lungs and ovaries were significantly lower in groups immunized with pA27LOPT and pA27LOPT+Imiquimod. These results demonstrate that our vaccine formulation decreases viral replication and dissemination in a virus-free DNA vaccine platform, and provides an alternative towards a safer an efficacious vaccine.

Differential association of 5-hydroxymethylcytosine levels with clinical and histopathological characteristics in breast cancer tumors

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Background: Breast cancer is one of the top causes of cancer death worldwide. In Mexico, locally advanced breast cancer (LABC) comprises the majority of the breast cancer stages at diagnosis. Recent studies have suggested that 5-hydroxymethylcytosine (5hmC), could be a prognostic marker in breast cancer. However, the role of 5hmC on clinical and histopathologic characteristics in LABC has not been explored. Methods: From a cohort of locally advanced and advanced breast cancer patients treated at the National Cancer Institute in Mexico City with a 3-year follow-up, we measured 5hmC levels by immunodetection from fresh frozen tissue samples taken from the initial biopsy (N = 193). We determined the association between 5hmC levels and the most relevant clinical and histopathological characteristics. Results: From the full cohort analyzed; 42% were luminal A (n = 82), 33% were luminal B (N = 63), 9% were HER2-positive (N = 18), and 15% were triple-negative tumors. We found higher levels of global 5hmC in HER2 positive tumors vs. all other subtypes (p = 0.028, Kruskal-Wallis test). In luminal B tumors, 5hmC levels were associated with Ki67 (β = -0.04, 95%CI: -0.08, -0.01, p = 0.01 from multivariable model) but not in luminal A. Furthermore, we found that low 5hmC levels were associated with higher histological grade in HER2-positive tumors (p = 0.03, Kruskal-Wallis test). In subgroup analysis of LABC patients, we found higher 5hmC levels in non-ductal vs. ductal invasive tumors (β = 1.38, 95%CI: 0.049, 2.911, p = 0.043 from multivariable model). Also, lower 5hmC levels were associated with Ki67 (β = -2.53, 95%CI: -4.32, -0.74; p = 0.009 from multivariable model) and with histological type (p = 0.028, Kruskal-Wallis test) in LABC luminal B tumors. A borderline association with OS (p = 0.07, log-rank test) and RFS (p = 0.071, log-rank test) was observed in luminal A tumors in the LABC group. Conclusions: Our findings suggest that 5hmC levels are differentially associated with distinct clinical and histopathological characteristics in breast cancer, especially those linked to aggressiveness, including Ki67, histological type, and grade.

Effects of Surgical Factors on Cartilage Can Be Detected Using Quantitative Magnetic Resonance Imaging After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Quantitative magnetic resonance (qMR) can be used to measure macromolecules in tissues and is a potential method of observing early cartilage changes in the development of posttraumatic osteoarthritis. Hypothesis/Purpose: We hypothesized that specific patient and surgical factors affecting cartilage matrix composition after anterior cruciate ligament (ACL) reconstruction (ACLR) can be detected using T1ρ and T2 relaxation times. Our purpose was to demonstrate this ability in a multicenter feasibility study.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 54 patients who underwent ACLR underwent bilateral MRI at baseline before surgery and 6 months postoperatively. Operative findings were recorded. T1ρ and T2 relaxation times were calculated for 6 cartilage regions: the medial femur, lateral femur, medial tibia, lateral tibia, patella, and trochlea. A paired t test compared relaxation times at baseline and 6 months, univariate regression identified regions that influenced patient-reported outcome measures, and analysis of covariance was used to determine the surgical factors that resulted in elevated relaxation times at 6 months.

RESULTS

The injured knee had significantly prolonged T1ρ and T2 relaxation times in the tibiofemoral compartment at baseline and 6 months but had shorter values in the patellofemoral compartment compared with the uninjured knee. Prolonged T1ρ and T2 times at 6 months were noted for both the injured and uninjured knees. At 6 months, prolongation of T1ρ and T2 times in the tibial region was associated with lower patient-reported outcome measures. ACLR performed within 30 days of injury had significantly shorter T1ρ times in the tibial regions, and lateral meniscal tears treated with repair had significantly shorter T1ρ times than those treated with excision.

CONCLUSION

Prolonged relaxation times in multiple regions demonstrate how the injury affects the entire joint after an ACL tear. Changes observed in the uninjured knee may be caused by increased loading during rehabilitation, especially in the patellofemoral articular cartilage and distal femur. Relaxation times in the tibial regions may be predictive of patient symptoms at 6 months. These same regions are affected by surgical timing as early as 30 days after injury, but this may partially be reflective of the severity of the preoperative injury and the choice of treatment of meniscal tears.