Regulation of BMP-induced ectopic bone formation by Ahsg.

alpha2-HS-glycoprotein (Ahsg), also known as fetuin is a serum and bone resident glycoprotein, which binds to TGF-beta superfamily members including bone morphogenetic proteins (BMP) and inhibits dexamethasone-induced osteogenesis in bone marrow cultures in vitro. Here we demonstrate that Ahsg reduces cytokine binding to its cognate receptor in HOS osteocyte cells and suppresses intracellular signaling, while in vivo, we test the hypothesis that Ahsg-deficient mice are hyper-responsive to BMP-induced osteogenesis. Human native BMP was implanted into the hindquarter muscles of Ahsg(+/+), Ahsg(+/-) and Ahsg(-/-) mice and 4 weeks later, ossicle formation was analyzed by radiography, bone density scanning (DEXA) and histomorphometry. Alkaline phosphatase (AP) activity was measured in ossicles as a marker for bone cell differentiation, and was significantly higher in Ahsg(-/-) versus Ahsg(+/-) and/or Ahsg(+/+) mice. Ectopic ossicle size in the Ahsg(+/-) mouse was 4-fold greater than that in the wild type (Ahsg(+/+)), and intermediate to that shown in Ahsg(-/-) mouse. Bone mineral density (BMD) was lower in the Ahsg(-/+) and Ahsg(-/-) mice compared to Ahsg(+/+) littermates. The ratio of cortical to cancellous bone was found to be >2-fold higher in Ahsg(-/-) mouse in comparison to the Ahsg(+/+) mice with no significant change in the Ahsg(-/+) mouse. Finally, a significantly higher incidence of satellite ossification; small islands of immature bone, was shown in Ahsg(-/-) mice as compared to Ahsg(+/+) mice. Although Ahsg binds to TGF-beta/BMP and blocks receptor signalling, it may also sequester cytokines in matrix, thereby acting as a reservoir of osteoinductive activity when released. This may explain the non-linear relationship between ectopic bone formation characteristics and Ahsg(+/+), Ahsg(+/-) and Ahsg(-/-) genotypes, although the increase in satellite bone formation might also explain this phenomenon. Our results suggest that Ahsg may be useful for prevention of the heterotopic ossification and the regulation of osteoinductive effects of BMP used with grafts.     

Inflammation, cardiovascular disease and nocturnal hemodialysis

PURPOSE OF REVIEW: There is a growing recognition that uremia is a proinflammatory condition. Chronic uremia-associated inflammation contributes to the pathogenesis of atherosclerosis, anemia and cardiovascular calcification in patients with end-stage renal disease (ESRD). Daily nocturnal hemodialysis (DNHD) is a form of frequent intensive renal replacement therapy that has multiple cardiovascular benefits. Here we will review the emerging data of DNHD on inflammation, coronary calcification and anemia management. RECENT FINDINGS: Increasing the dose and frequency of dialysis by DNHD has been demonstrated, in both short and long-term studies, to reverse several important risk factors for adverse cardiovascular events in ESRD patients. In addition, there are preliminary data indicating the positive effects of DNHD on inflammatory cytokine profile, rate of coronary calcification progression and enhanced erythropoietin responsiveness. SUMMARY: Augmentation of dialysis dose by DNHD may positively influence uremia-related inflammation. The role of intensive dialysis as a treatment for chronic inflammation requires further research.     

Advances in Predicting and Manipulating the Immunogenicity of Biotherapeutics and Vaccines

Therapeutic proteins are vital to the future of human health provision and the survival and profitability of the global pharmaceutical industry. Returns from protein therapeutics are experiencing unprecedented growth: both their number and their economic dividend have increased by an order of magnitude in the last 10 years. The potential immunogenicity of protein therapeutics raises many clinical and safety concerns. Many poorly understood factors relating to both product and host affect immune responses. Available laboratory measurement of immunogenicity is of little utility for predicting the clinical properties of biotherapeutics. Coupled with assay variability and standardization issues, this precludes adequate prediction of the biological or clinical responses of therapeutic proteins, arguing for the utilization of informatic strategies in the analysis and prediction of protein immunogenicity. Currently, many unresolved issues must be addressed and thus circumvented before effective prediction can become routine.     

Induction of advanced glycation end products and alterations of the tensile properties of articular cartilage

OBJECTIVE: To determine whether increasing advanced glycation end products (AGEs) in bovine articular cartilage to levels present in aged human cartilage modulates the tensile biomechanical properties of the tissue. METHODS: Adult bovine articular cartilage samples were incubated in a buffer solution with ribose to induce the formation of AGEs or in a control solution. Portions of cartilage samples were assayed for biochemical indices of AGEs and tested to assess their tensile biomechanical properties, including stiffness, strength, and elongation at failure. RESULTS: Ribose treatment of cartilage induced increases in tissue fluorescence, absorbance, and pentosidine content (P < 0.001 for each comparison) by amounts similar to those that occur during aging in humans. Ribose treatment of cartilage also induced an increase in dynamic modulus (60% increase) and strength (35% increase), and a decrease (25% decrease) in strain (P < 0.001 for each comparison). CONCLUSION: The concomitant increase in AGEs and alteration of tensile properties of cartilage after ribose treatment suggest that aging-associated changes in AGEs have functional consequences for this tissue. The AGE-associated increases in strength and stiffness of cartilage may be beneficial by counteracting the decreases in these properties that are associated with degeneration. Conversely, the AGE-associated decrease in failure length, or increase in brittleness, together with increased stiffness may predispose cartilage to increased stress concentration, fracture, and aging-associated biomechanical dysfunction.     

Effect of Display Resolution on Time to Diagnosis with Virtual Pathology Slides in a Systematic Search Task

Performing diagnoses using virtual slides can take pathologists significantly longer than with glass slides, presenting a significant barrier to the use of virtual slides in routine practice. Given the benefits in pathology workflow efficiency and safety that virtual slides promise, it is important to understand reasons for this difference and identify opportunities for improvement. The effect of display resolution on time to diagnosis with virtual slides has not previously been explored. The aim of this study was to assess the effect of display resolution on time to diagnosis with virtual slides. Nine pathologists participated in a counterbalanced crossover study, viewing axillary lymph node slides on a microscope, a 23-in 2.3-megapixel single-screen display and a three-screen 11-megapixel display consisting of three 27-in displays. Time to diagnosis and time to first target were faster on the microscope than on the single and three-screen displays. There was no significant difference between the microscope and the three-screen display in time to first target, while the time taken on the single-screen display was significantly higher than that on the microscope. The results suggest that a digital pathology workstation with an increased number of pixels may make it easier to identify where cancer is located in the initial slide overview, enabling quick location of diagnostically relevant regions of interest. However, when a comprehensive, detailed search of a slide has to be made, increased resolution may not offer any additional benefit.     

Validation of a Systemic Lupus Activity Questionnaire (SLAQ) for population studies

The goal of this work was to develop an economical way of tracking disease activity for large groups of systemic lupus erythematosus (SLE) patients in clinical studies. A Systemic Lupus Activity Questionnaire (SLAQ) was developed to screen for possible disease activity using items from the Systemic Lupus Activity Measure (SLAM) and tested for its measurement properties. The SLAQ was completed by 93 SLE patients just prior to a scheduled visit. At the visit, a rheumatologist, blinded to SLAQ results, examined the subject and completed a SLAM. Associations among SLAQ, and SLAM (omitting laboratory items) and between individual items from each instrument were assessed with Pearson correlations. Correlations between pairs of instruments were compared using Student's t-tests. The mean score across all 24 SLAQ items was 11.5 (range 0-33); mean SLAM without labs was 3.0 (range 0-13). The SLAQ had a moderately high correlation with SLAM-nolab (r = 0.62, P < 0.0001). Correlations between patient-clinician matched pairs of items ranged from r = 0.06 to 0.71. Positive predictive values for the SLAQ ranged from 56 to 89% for detecting clinically significant disease activity. In studies of SLE, symptoms suggesting disease can be screened by self-report using the SLAQ and then verified by further evaluation.     

Rapid review of virus risk communication interventions: Directions for COVID-19

ObjectiveIn response to COVID-19, we conducted a rapid review of risk communication interventions to mitigate risk from viruses to determine if such interventions are efficacious.MethodsWe searched for risk communication interventions in four databases: Medline, PsycInfo, the ProQuest Coronavirus Research Database, and CENTRAL. The search produced 1572 articles. Thirty-one articles were included in the final review.ResultsResults showed risk communication interventions can produce cognitive and behavior changes around viruses. Results were more consistently positive for interventions focused on HIV/AIDS as compared to influenza. There was no consistent best intervention approach when comparing peer health, audio/visual, and intensive multi-media interventions. Tailoring risk communication toward a target population, in comparison to not tailoring, was related to better outcomes.ConclusionThe results suggest that risk communication interventions can be efficacious at reducing risk from viruses. They also highlight the complexity of risk communication interventions. Additional research is needed to understand the mechanisms that lead risk communication to reduce risk from viruses.Practical valueResults support risk communication interventions to reduce risk from viruses.