Increased β2-adrenergic signaling promotes fracture healing through callus neovascularization in mice

Traumatic brain injury (TBI) leads to skeletal changes, including bone loss in the unfractured skeleton, and paradoxically accelerates healing of bone fractures; however, the mechanisms remain unclear. TBI is associated with a hyperadrenergic state characterized by increased norepinephrine release. Here, we identified the β2-adrenergic receptor (ADRB2) as a mediator of skeletal changes in response to increased norepinephrine. In a murine model of femoral osteotomy combined with cortical impact brain injury, TBI was associated with ADRB2-dependent enhanced fracture healing compared with osteotomy alone. In the unfractured 12-week-old mouse skeleton, ADRB2 was required for TBI-induced decrease in bone formation and increased bone resorption. Adult 30-week-old mice had higher bone concentrations of norepinephrine, and ADRB2 expression was associated with decreased bone volume in the unfractured skeleton and better fracture healing in the injured skeleton. Norepinephrine stimulated expression of vascular endothelial growth factor A and calcitonin gene-related peptide-α (αCGRP) in periosteal cells through ADRB2, promoting formation of osteogenic type-H vessels in the fracture callus. Both ADRB2 and αCGRP were required for the beneficial effect of TBI on bone repair. Adult mice deficient in ADRB2 without TBI developed fracture nonunion despite high bone formation in uninjured bone. Blocking ADRB2 with propranolol impaired fracture healing in mice, whereas the ADRB2 agonist formoterol promoted fracture healing by regulating callus neovascularization. A retrospective cohort analysis of 72 patients with long bone fractures indicated improved callus formation in 36 patients treated with intravenous norepinephrine. These findings suggest that ADRB2 is a potential therapeutic target for promoting bone healing.

Tranexamic Acid Attenuates the Progression of Posttraumatic Osteoarthritis in Mice

BACKGROUND

Posttraumatic osteoarthritis (OA) is a common disorder associated with a high socioeconomic burden, particularly in young, physically active, and working patients. Tranexamic acid (TXA) is commonly used in orthopaedic trauma surgery as an antifibrinolytic agent to control excessive bleeding. Previous studies have reported that TXA modulates inflammation and bone cell function, both of which are dysregulated during posttraumatic OA disease progression.

PURPOSE

To evaluate the therapeutic effects of systemic and topical TXA treatment on the progression of posttraumatic OA in the knee of mice.

STUDY DESIGN

Controlled laboratory study.

METHODS

OA was induced via anterior cruciate ligament (ACL) transection on the right knee of female mice. Mice were treated with TXA or vehicle intraperitoneally daily or intra-articularly weekly for 4 weeks, starting on the day of surgery. Articular cartilage degeneration, synovitis, bone erosion, and osteophyte formation were scored histologically. Micro-computed tomography evaluation was conducted to measure the subchondral bone microstructure and osteophyte volume. Cartilage thickness and bone remodeling were assessed histomorphometrically.

RESULTS

Both systemic and topical TXA treatment significantly reduced cartilage degeneration, synovitis, and bone erosion scores and increased the ratio of hyaline to calcified cartilage thickness in posttraumatic OA. Systemic TXA reversed ACL transection-induced subchondral bone loss and osteophyte formation, whereas topical treatment had no effect. Systemic TXA decreased the number and surface area of osteoclasts, whereas those of osteoblasts were not affected. No effect of topical TXA on osteoblast or osteoclast parameters was observed.

CONCLUSION

Both systemic and topical TXA exerted protective effects on the progression of posttraumatic OA. Drug repurposing of TXA may, therefore, be useful for the prevention or treatment of posttraumatic OA, particularly after ACL surgery.

CLINICAL RELEVANCE

TXA might be beneficial in patients with posttraumatic OA of the knee.

Piezo1 expression in chondrocytes controls endochondral ossification and osteoarthritis development

Piezo proteins are mechanically activated ion channels, which are required for mechanosensing functions in a variety of cell types. While we and others have previously demonstrated that the expression of Piezo1 in osteoblast lineage cells is essential for bone-anabolic processes, there was only suggestive evidence indicating a role of Piezo1 and/or Piezo2 in cartilage. Here we addressed the question if and how chondrocyte expression of the mechanosensitive proteins Piezo1 or Piezo2 controls physiological endochondral ossification and pathological osteoarthritis (OA) development. Mice with chondrocyte-specific inactivation of Piezo1 (Piezo1Col2a1Cre), but not of Piezo2, developed a near absence of trabecular bone below the chondrogenic growth plate postnatally. Moreover, all Piezo1Col2a1Cre animals displayed multiple fractures of rib bones at 7 days of age, which were located close to the growth plates. While skeletal growth was only mildly affected in these mice, OA pathologies were markedly less pronounced compared to littermate controls at 60 weeks of age. Likewise, when OA was induced by anterior cruciate ligament transection, only the chondrocyte inactivation of Piezo1, not of Piezo2, resulted in attenuated articular cartilage degeneration. Importantly, osteophyte formation and maturation were also reduced in Piezo1Col2a1Cre mice. We further observed increased Piezo1 protein abundance in cartilaginous zones of human osteophytes. Finally, we identified Ptgs2 and Ccn2 as potentially relevant Piezo1 downstream genes in chondrocytes. Collectively, our data do not only demonstrate that Piezo1 is a critical regulator of physiological and pathological endochondral ossification processes, but also suggest that Piezo1 antagonists may be established as a novel approach to limit osteophyte formation in OA.

Transcript-dependent effects of the CALCA gene on the progression of post-traumatic osteoarthritis in mice

Osteoarthritis represents a chronic degenerative joint disease with exceptional clinical relevance. Polymorphisms of the CALCA gene, giving rise to either a procalcitonin/calcitonin (PCT/CT) or a calcitonin gene-related peptide alpha (αCGRP) transcript by alternative splicing, were reported to be associated with the development of osteoarthritis. The objective of this study was to investigate the role of both PCT/CT and αCGRP transcripts in a mouse model of post-traumatic osteoarthritis (ptOA). WT, αCGRP-/- and CALCA-/- mice were subjected to anterior cruciate ligament transection (ACLT) to induce ptOA of the knee. Mice were sacrificed 4 and 8 weeks post-surgery, followed by micro-CT and histological evaluation. Here we show that the expression of both PCT/CT and αCGRP transcripts is induced in ptOA knees. CALCA-/- mice show increased cartilage degeneration and subchondral bone loss with elevated osteoclast numbers compared to αCGRP-/- and WT mice. Osteophyte formation is reduced to the same extent in CALCA-/- and αCGRP-/- mice compared to WT controls, while a reduced synovitis score is noticed exclusively in mice lacking CALCA. Our data show that expression of the PCT/CT transcript protects from the progression of ptOA, while αCGRP promotes osteophyte formation, suggesting that CALCA-encoded peptides may represent novel targets for the treatment of ptOA.

RHEGMATOGENOUS RETINAL DETACHMENT AFTER INJECTION OF TISSUE PLASMINOGEN ACTIVATOR AND GAS FOR SUBMACULAR HEMORRHAGE SECONDARY TO AGE-RELATED MACULAR DEGENERATION

PURPOSE

The purpose of this study was to describe the rate, clinical characteristics, and outcomes of rhegmatogenous retinal detachment (RRD) after injection of tissue plasminogen activator (TPA) and gas for submacular hemorrhage displacement.

METHODS

Retrospective analysis of consecutive cases developing RRD after TPA injection and gas for submacular hemorrhage displacement. The rate of RRD was calculated, and a description of RRD clinical characteristics was performed. Anatomic and visual outcomes after RRD repair were analyzed.

RESULTS

Ninety eyes of 90 patients were analyzed. Tissue plasminogen activator was given intravitreally in 53 eyes (59%) and subretinally in 37 eyes (41%). RRD occurred in 6 of 90 eyes (7%). Of these, one had intravitreal TPA and five had vitrectomy with subretinal TPA ( P = 0.04). The mean age was 75 (64-93) years. The median time of RRD occurrence was 42 (1-134) days. All cases had macular involvement. Two cases had PVR at presentation. Vitrectomy was performed in all cases and silicone oil used in five, all of which resulted in permanent silicone oil retention. One case (17%) achieved primary single surgery success. The median final visual acuity was 1.8 logMAR (20/1,260 Snellen).

CONCLUSION

The RRD rate after submacular hemorrhage displacement was 7% in our case series. Rhegmatogenous retinal detachment occurred more commonly after vitrectomy with subretinal TPA injection. The visual and anatomic outcomes were poor, with a high rate of retained silicone oil and recurrent RRD.

I like it because it hurts you: On the association of everyday sadism, sadistic pleasure, and victim blaming

Past research on determinants of victim blaming mainly concentrated on individuals' just-world beliefs as motivational process underlying this harsh reaction to others' suffering. The present work provides novel insights regarding underlying affective processes by showing how individuals prone to derive pleasure from others' suffering-individuals high in everyday sadism-engage in victim blaming due to increased sadistic pleasure and reduced empathic concern they experience. Results of three cross-sectional studies and one ambulatory assessment study applying online experience sampling method (ESM; overall N = 2,653) document this association. Importantly, the relation emerged over and above the honesty-humility, emotionality, extraversion, agreeableness, conscientiousness, and openness personality model (Study 1a), and other so-called dark traits (Study 1b), across different cultural backgrounds (Study 1c), and also when sampling from a population of individuals frequently confronted with victim-perpetrator constellations: police officers (Study 1d). Studies 2 and 3 highlight a significant behavioral correlate of victim blaming. Everyday sadism is related to reduced willingness to engage in effortful cognitive activity as individuals high (vs. low) in everyday sadism recall less information regarding victim-perpetrator constellations of sexual assault. Results obtained in the ESM study (Study 4) indicate that the relation of everyday sadism, sadistic pleasure, and victim blaming holds in everyday life and is not significantly moderated by interpersonal closeness to the blamed victim or impactfulness of the incident. Overall, the present article extends our understanding of what determines innocent victims' derogation and highlights emotional mechanisms, societal relevance, and generalizability of the observed associations beyond the laboratory. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Nesting behavior is associated with body weight and grip strength loss in mice suffering from experimental arthritis

Objective animal health evaluation is essential to determine welfare and discomfort in preclinical in vivo research. Body condition scores, body weight, and grimace scales are commonly used to evaluate well-being in murine rheumatoid arthritis (RA) and osteoarthritis experiments. However, nest-building, a natural behavior in mice, has not yet been evaluated in wild type (WT) or genetically modified rodents suffering from collagen antibody-induced arthritis (CAIA). To address this, we analyzed nesting behavior in WT mice, calcitonin gene-related peptide alpha-deficient (αCGRP-/-) mice, and calcitonin receptor-deficient (Calcr-/-) mice suffering from experimental RA compared to healthy control (CTRL) groups of the same genotypes. CAIA was induced in 10-12-week-old male mice, and clinical parameters (body weight, grip strength, clinical arthritis score, ankle size) as well as nesting behavior were assessed over 10 or 48 days. A slight positive association between the nest score and body weight and grip strength was found for animals suffering from CAIA. For the clinical arthritis score and ankle size, no significant associations were observed. Mixed model analyses confirmed these associations. This study demonstrates that clinical effects of RA, such as loss of body weight and grip strength, might negatively affect nesting behavior in mice. Assessing nesting behavior in mice with arthritis could be an additional, non-invasive and thus valuable health parameter in future experiments to monitor welfare and discomfort in mice. During severe disease stages, pre-formed nest-building material may be provided to animals suffering from arthritis.

A rotationally-driven dynamic solid phase sodium bisulfite conversion disc for forensic epigenetic sample preparation

The approaches to forensic human identification (HID) are largely comparative in nature, relying upon the comparison of short tandem repeat profiles to known reference materials and/or database profiles. However, many profiles are generated from evidence materials that either do not have a reference material for comparison or do not produce a database hit. As an alternative to individualizing analysis for HID, researchers of forensic DNA have demonstrated that the human epigenome can provide a wealth of information. However, epigenetic analysis requires sodium b̲is̲ulfite c̲onversion (BSC), a sample preparation method that is time-consuming, labor-intensive, prone to contamination, and characterized by DNA loss and fragmentation. To provide an alternative method for BSC that is more amenable to integration with the forensic DNA workflow, we describe a rotationally-driven, microfluidic method for dynamic solid phase-BSC (dSP-BSC) that streamlines the sample preparation process in an automated format, capable of preparing up to four samples in parallel. The method permitted decreased incubation intervals by ∼36% and was assessed for relative DNA recovery and conversion efficiency and compared to gold-standard and enzymatic approaches.

The dual pro-inflammatory and bone-protective role of calcitonin gene-related peptide alpha in age-related osteoarthritis

BACKGROUND

The vasoactive neuropeptide calcitonin gene-related peptide alpha (αCGRP) enhances nociception in primary knee osteoarthritis (OA) and has been shown to disrupt cartilage and joint integrity in experimental rheumatoid arthritis (RA). Little is known about how αCGRP may alter articular structures in primary OA. We investigated whether αCGRP modulates local inflammation and concomitant cartilage and bone changes in a murine model of age-dependent OA.

METHODS

Sixteen- to 18-month-old αCGRP-deficient mice (αCGRP-/-aged) were compared to, first, age-matched wild type (WTaged) and, second, young 4- to 5-month-old non-OA αCGRP-deficient (αCGRP-/-CTRL) and non-OA WT animals (WTCTRL). αCGRP levels were measured in serum. Knee and hip joint inflammation, cartilage degradation, and bone alterations were assessed by histology (OARSI histopathological grading score), gene expression analysis, and µ-computed tomography.

RESULTS

WTaged mice exhibited elevated αCGRP serum levels compared to young WTCTRL animals. Marked signs of OA-induced cartilage destruction were seen in WTaged animals, while αCGRP-/-aged mice were mostly protected from this effect. Age-dependent OA was accompanied by an increased gene expression of pro-inflammatory Tnfa, Il1b, and Il6 and catabolic Mmp13, Adamts5, Ctsk, Tnfs11 (Rankl), and Cxcl12/Cxcr4 in WTaged but not in αCGRP-/-aged mice. αCGRP-deficiency however further aggravated subchondral bone sclerosis of the medial tibial plateau and accelerated bone loss in the epi- and metaphyseal trabecular tibial bone in age-dependent OA.

CONCLUSIONS

Similar to its function in experimental RA, αCGRP exerts a dual pro-inflammatory and bone-protective function in murine primary OA. Although anti-CGRP treatment was previously not successful in reducing pain in OA clinically, these data underline a crucial pathophysiological role of αCGRP in age-related OA.

On the social signal function of emotional crying: Broadening the perspective to social interactions in daily life

Emotional crying is a potent signal that can influence how social interactions unfold. Although the social signal function of crying has been mostly studied in experimental approaches involving hypothetical scenarios with strangers as targets, we propose that daily social interactions should be considered to address aspects of external validity. We conducted three retrospective studies (total N = 2,277; convenience samples; Studies 2 and 3 were preregistered; data were collected in 2022 and 2023) and found that individuals primarily observed close others crying in their daily lives; a boundary condition that was hardly reflected in former studies. Crying episodes were typically characterized by tears and changes in facial expression, vocalizations, and gestures, whereas isolated emotional tears, were rarely reported. Participants indicated that they frequently helped close others, but that helping strangers was the exception. The level of familiarity with the target also influenced the form of help provided. Furthermore, the crying person was rated as less warm and less competent when crying (vs. in general or in a neutral situation). Additional analyses suggest that question order effects and recall biases are no plausible alternative explanations of our findings. Taken together, these results call into question the validity of the experimental approaches used in this line of research. We discuss strategies for future study of the social signal function of crying in nonhypothetical scenarios with reference to the "generalizability crisis" of psychological science. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The selective norepinephrine reuptake inhibitor reboxetine promotes late-stage fracture healing in mice

Impaired fracture healing is of high clinical relevance, as up to 15% of patients with long-bone fractures display non-unions. Fracture patients also include individuals treated with selective norepinephrine reuptake inhibitors (SNRI). As SNRI were previously shown to negatively affect bone homeostasis, it remained unclear whether patients with SNRI are at risk of impaired bone healing. Here, we show that daily treatment with the SNRI reboxetine reduces trabecular bone mass in the spine but increases cortical thickness and osteoblast numbers in the femoral midshaft. Most importantly, reboxetine does not impair bone regeneration in a standardized murine fracture model, and even improves callus bridging and biomechanical stability at late healing stages. In sum, reboxetine affects bone remodeling in a site-specific manner. Treatment does not interfere with the early and intermediate stages of bone regeneration and improves healing outcomes of the late-stage fracture callus in mice.

Increased local bone turnover in patients with chronic periprosthetic joint infection

Aims

The management of periprosthetic joint infection (PJI) remains a major challenge in orthopaedic surgery. In this study, we aimed to characterize the local bone microstructure and metabolism in a clinical cohort of patients with chronic PJI.

Methods

Periprosthetic femoral trabecular bone specimens were obtained from patients suffering from chronic PJI of the hip and knee (n = 20). Microbiological analysis was performed on preoperative joint aspirates and tissue specimens obtained during revision surgery. Microstructural and cellular bone parameters were analyzed in bone specimens by histomorphometry on undecalcified sections complemented by tartrate-resistant acid phosphatase immunohistochemistry. Data were compared with control specimens obtained during primary arthroplasty (n = 20) and aseptic revision (n = 20).

Results

PJI specimens exhibited a higher bone volume, thickened trabeculae, and increased osteoid parameters compared to both control groups, suggesting an accelerated bone turnover with sclerotic microstructure. On the cellular level, osteoblast and osteoclast parameters were markedly increased in the PJI cohort. Furthermore, a positive association between serum (CRP) but not synovial (white blood cell (WBC) count) inflammatory markers and osteoclast indices could be detected. Comparison between different pathogens revealed increased osteoclastic bone resorption parameters without a concomitant increase in osteoblasts in bone specimens from patients with Staphylococcus aureus infection, compared to those with detection of Staphylococcus epidermidis and Cutibacterium spp.

Conclusion

This study provides insights into the local bone metabolism in chronic PJI, demonstrating osteosclerosis with high bone turnover. The fact that Staphylococcus aureus was associated with distinctly increased osteoclast indices strongly suggests early surgical treatment to prevent periprosthetic bone alterations.

Performance and Hypothetical Impact on Joint Infection Management of the BioFire Joint Infection Panel: a Retrospective Analysis

Pathogen identification is key in septic arthritis. Culture-based techniques are challenging, especially when patients have been pretreated with antibiotics or when difficult-to-culture bacteria are encountered. The BioFire joint infection assay (BJA) is a multiplex PCR panel which detects 31 of the most prevalent bacterial and fungal pathogens causing septic arthritis. Here, 123 cryoconserved contemporary synovial fluid samples from 120 patients underwent BJA analysis. Results were compared to those of culture-based diagnostics (standard of care [SOC]). Clinical data were collected, and the possible impact of the molecular diagnostic application on patient management was evaluated. Fifteen of 123 synovial fluid cultures grew bacterial pathogens. All on-panel pathogens (9/15) were correctly identified by the BJA. The BJA identified four additional bacterial pathogens in four SOC-negative cases. BJA sensitivity and specificity were 100% (95% confidence interval [CI], 69.2% to 100%) and 100% (95% CI, 96.8% to 100%), respectively. Compared to the SOC, the BJA would have resulted in faster provision of species identification and molecular susceptibility data by 49 h and 99 h, respectively. Clinical data analysis indicates that in BJA-positive cases, faster species ID could have led to timelier optimization of antibiotic therapy. This retrospective study demonstrates high sensitivity and specificity of the BJA to detect on-panel organisms in bacterial arthritis. The usefulness of the BJA in prosthetic-joint infections is limited, as important pathogens (i.e., coagulase negative staphylococci and Cutibacterium acnes) are not covered. Evidence from patient data analysis suggests that the assay might prove valuable for optimizing patient management in acute arthritis related to fastidious organisms or for patients who received antibiotics prior to specimen collection.

Retinal detachment after post-operative endophthalmitis: clinical characteristics, outcomes and risk factors

PURPOSE

To describe clinical characteristics, risk factors, and outcomes of rhegmatogenous retinal detachment (RRD) following treatment of postoperative endophthalmitis (PE).

METHODS

Analysis of cross-referenced data from two service reviews of patients with RRD and bacterial PE treated between 01/01/2013 and 01/07/2020. The main outcome measure was final best-corrected visual acuity (BCVA). Secondary measures include proportion of patients with BCVA of ≤ 0.3 logMAR and ≥ 1.0 logMAR, rate of phthsis, and rate of eye removal.

RESULTS

Ninety-four cases of PE were analysed finding 21 cases of RRD (22%). Seven (35%) experienced recurrent RRD. Seven eyes (35%) were left with permanent silicone oil fill. All RRD cases had vitrectomy. After PE with RRD the median BCVA was 1.1 logMAR, compared with 0.4 logMAR for PE without RRD (p < 0.04). Fifty-seven percent (12/21) of RRD eyes attained BCVA of ≥ 1.0 logMAR vs. 29% (21/73) of PE without RRD (p = 0.01). Nineteen percent (4/21) of eyes with RRD attained BCVA of ≤ 0.3 logMAR, whereas those without RRD did so in 43% (31/73) of cases (p = 0.02). Five eyes with RRD (24%) and 2 eyes without RRD (3%) developed phthisis (p < 0.01). Three non-RRD cases required removal of the eye (4%, p = 0.46). Higher bacterial virulence was associated with worse final BCVA (2.1 logMAR vs. 0.3 logMAR; p < 0.01). RRD rate did not differ by bacterial virulence (OR 1.9; CI95: 0.6-6.9; p = 0.24).

CONCLUSIONS

RRD following PE leads to worse clinical outcomes. Eyes which developed RRD were more likely to have undergone vitrectomy. Final BCVA was worse in cases with more virulent micro-organisms.

Increased beta2-adrenergic signaling is a targetable stimulus essential for bone healing by promoting callus neovascularization

Traumatic brain injury (TBI) is associated with a hyperadrenergic state and paradoxically causes systemic bone loss while accelerating fracture healing. Here, we identify the beta2-adrenergic receptor (Adrb2) as a central mediator of these skeletal manifestations. While the negative effects of TBI on the unfractured skeleton can be explained by the established impact of Adrb2 signaling on bone formation, Adrb2 promotes neovascularization of the fracture callus under conditions of high sympathetic tone, including TBI and advanced age. Mechanistically, norepinephrine stimulates the expression of Vegfa and Cgrp primarily in periosteal cells via Adrb2, both of which synergistically promote the formation of osteogenic type-H vessels in the fracture callus. Accordingly, the beneficial effect of TBI on bone repair is abolished in mice lacking Adrb2 or Cgrp, and aged Adrb2-deficient mice without TBI develop fracture nonunions despite high bone formation in uninjured bone. Pharmacologically, the Adrb2 antagonist propranolol impairs, and the agonist formoterol promotes fracture healing in aged mice by regulating callus neovascularization. Clinically, intravenous beta-adrenergic sympathomimetics are associated with improved callus formation in trauma patients with long bone fractures. Thus, Adrb2 is a novel target for promoting bone healing, and widely used beta-blockers may cause fracture nonunion under conditions of increased sympathetic tone.

Abstract Figure

Fracture healing in a mouse model of Hajdu-Cheney-Syndrome with high turnover osteopenia results in decreased biomechanical stability

Notch signaling regulates cell fate in multiple tissues including the skeleton. Hajdu-Cheney-Syndrome (HCS), caused by gain-of-function mutations in the Notch2 gene, is a rare inherited disease featuring early-onset osteoporosis and increased risk for fractures and non-union. As the impact of Notch2 overactivation on fracture healing is unknown, we studied bone regeneration in mice harboring a human HCS mutation. HCS mice, displaying high turnover osteopenia in the non-fractured skeleton, exhibited only minor morphologic alterations in the progression of bone regeneration, evidenced by static radiological and histological outcome measurements. Histomorphometry showed increased osteoclast parameters in the callus of HCS mice, which was accompanied by an increased expression of osteoclast and osteoblast markers. These observations were accompanied by inferior biomechanical stability of healed femora in HCS mice. Together, our data demonstrate that structural indices of bone regeneration are normal in HCS mice, which, however, exhibit signs of increased callus turnover and display impaired biomechanical stability of healed fractures.

Using Digital Twins to Support Multiple Stages of the Patient Journey

New possibilities in personalized medicine need to be complemented by clinical decision support systems as well as context-specific applications to be used in clinical routine. We aim to implement a shared technical backend for a large variety of applications in personalized head-and-neck cancer treatment. The infrastructure is conceptualized as a multi-purpose digital twin for cancer treatment. A set of prototypes of clinical applications demonstrates the feasibility of using digital twins to support multiple stages of the patient journey.

Inactivation of the gene encoding procalcitonin prevents antibody-mediated arthritis

BACKGROUND

Procalcitonin (PCT) is applied as a sensitive biomarker to exclude bacterial infections in patients with rheumatoid arthritis (RA) flare-ups. Beyond its diagnostic value, little is known about the pathophysiological role of PCT in RA.

METHODS

Collagen antibody-induced arthritis (CAIA) was induced in Calca-deficient mice (Calca^-/-), lacking PCT (n = 15), and wild-type (WT) mice (n = 13), while control (CTRL) animals (n = 8 for each genotype) received phosphate-buffered saline. Arthritis severity and grip strength were assessed daily for 10 or 48 days. Articular inflammation, cartilage degradation, and bone lesions were assessed by histology, gene expression analysis, and µ-computed tomography.

RESULTS

Serum PCT levels and intra-articular PCT expression increased following CAIA induction. While WT animals developed a full arthritic phenotype, Calca-deficient mice were protected from clinical and histological signs of arthritis and grip strength was preserved. Cartilage turnover markers and Tnfa were exclusively elevated in WT mice. Calca-deficient animals expressed increased levels of Il1b. Decreased bone surface and increased subchondral bone porosity were observed in WT mice, while Calca-deficiency preserved bone integrity.

CONCLUSION

The inactivation of Calca and thereby PCT provided full protection from joint inflammation and arthritic bone loss in mice exposed to CAIA. Together with our previous findings on the pathophysiological function of Calca-derived peptides, these data indicate an independent pro-inflammatory role of PCT in RA.

Nuclear Equation of State for Arbitrary Proton Fraction and Temperature Based on Chiral Effective Field Theory and a Gaussian Process Emulator

We calculate the equation of state of asymmetric nuclear matter at finite temperature based on chiral effective field theory interactions to next-to-next-to-next-to-leading order. Our results assess the theoretical uncertainties from the many-body calculation and the chiral expansion. Using a Gaussian process emulator for the free energy, we derive the thermodynamic properties of matter through consistent derivatives and use the Gaussian process to access arbitrary proton fraction and temperature. This enables a first nonparametric calculation of the equation of state in beta equilibrium, and of the speed of sound and the symmetry energy at finite temperature. Moreover, our results show that the thermal part of the pressure decreases with increasing densities.

Standard values of the upper body posture in healthy adults with special regard to age, sex and BMI

In order to classify and analyze the parameters of upper body posture in clinical or physiotherapeutic settings, a baseline in the form of standard values with special regard to age, sex and BMI is required. Thus, subjectively healthy men and women aged 21-60 years were measured in this project. The postural parameters of 800 symptom-free male (n = 397) and female (n = 407) volunteers aged 21-60 years (Ø♀: 39.7 ± 11.6, Ø ♂: 40.7 ± 11.5 y) were studied. The mean height of the men was 1.8 ± 0.07 m, with a mean body weight of 84.8 ± 13.1 kg and an average BMI of 26.0 ± 3.534 kg/m². In contrast, the mean height of the women was 1.67 ± 0.06 m, with a mean body weight of 66.5 ± 12.7 kg and an average BMI of 23.9 ± 4.6 kg/m². By means of video rasterstereography, a 3-dimensional scan of the upper back surface was measured when in a habitual standing position. The means or medians, confidence intervals, tolerance ranges, the minimum, 2.5, 25, 50, 75, 97.5 percentiles and the maximum, plus the kurtosis and skewness of the distribution, were calculated for all parameters. Additionally, ANOVA and a factor analyses (sex, BMI, age) were conducted. In both sexes across all age groups, balanced, symmetrical upper body statics were evident. Most strikingly, the females showed greater thoracic kyphosis and lumbar lordosis angles (kyphosis: Ø ♀ 56°, Ø♂ 51°; lordosis: Ø ♀ 49°, Ø♂ 32°) and lumbar bending angles (Ø ♀ 14°, Ø♂ 11°) than the males. The distance between the scapulae was more pronounced in men. These parameters also show an increase with age and BMI, respectively. Pelvic parameters were independent of age and sex. The upper body postures of women and men between the ages of 21 and 60 years were found to be almost symmetrical and axis-conforming with a positive correlation for BMI or age. Consequently, the present body posture parameters allow for comparisons with other studies, as well as for the evaluation of clinical (interim) diagnostics and applications.

Heavy silicone oil tamponade: a multicentre experience

OBJECTIVE

To report multicentred use of the heavy silicone oil Densiron 68 for anatomical reattachment following rhegmatogenous retinal detachment (RRD) repair and its associated complications.

METHODS AND ANALYSIS

Patients from seven vitreoretinal units within the UK that underwent RRD repair with Densiron 68 between January 2015 and December 2019 were identified. Primary outcome measures were primary and final reattachment rate, retained Densiron and failure rate. Secondary outcome measures were duration of tamponade, final visual acuity (VA) and complications of heavy silicone oil.

RESULTS

134 eyes of 134 patients were involved in the study. Primary surgical success was achieved in 48.5%, while a final reattachment rate of 73.4% was observed. The mean duration of Densiron 68 tamponade was 139.5 days. Mean final VA was 1.01 (range 0-2.9). 8 eyes (6.0%) required long-term topical steroids for anterior uveitis, whereas none of the eyes required long-term pressure-lowering treatment. Emulsification rate was 10.7% (6 eyes).

CONCLUSION

This is the largest real-world study on Densiron 68 in the UK. Densiron 68 facilitates tamponade of inferior retinal pathology and may be considered as an option for tamponade of inferior retinal pathologies.

From asymmetric to symmetric consumption opportunities: Extractions from common resources by privileged and underprivileged group members

In social dilemmas, asymmetric opportunities among actors can aggravate the conflict between individual and collective interests. We examine if and under what conditions redistributing extraction opportunities symmetrically fosters sustainable resource consumption. Participants in two studies (total n=640) completed a common resource game, first under asymmetric distribution of extraction opportunities (i.e., two advantaged group members could extract more than two disadvantaged group members) and then under symmetric distribution (i.e., all group members could extract the same amount). Advantaged (vs. disadvantaged) individuals took more from the resource in the asymmetric game and voted more often for the maintenance of the asymmetric system. Consumption was overall not more sustainable under symmetric (vs. asymmetric) distribution. We did not find evidence that these effects depend on the legitimacy of status positions. Of note, the symmetric game elicited higher satisfaction and fairness ratings in both status groups. The findings demonstrate how unequal access to resources fosters unequal consumption despite broad support for symmetry as the fairer system.

Design and validation of a medical robotic device system to control two collaborative robots for ultrasound-guided needle insertions

The percutaneous biopsy is a critical intervention for diagnosis and staging in cancer therapy. Robotic systems can improve the efficiency and outcome of such procedures while alleviating stress for physicians and patients. However, the high complexity of operation and the limited possibilities for robotic integration in the operating room (OR) decrease user acceptance and the number of deployed robots. Collaborative systems and standardized device communication may provide approaches to overcome named problems. Derived from the IEEE 11073 SDC standard terminology of medical device systems, we designed and validated a medical robotic device system (MERODES) to access and control a collaborative setup of two KUKA robots for ultrasound-guided needle insertions. The system is based on a novel standard for service-oriented device connectivity and utilizes collaborative principles to enhance user experience. Implementing separated workflow applications allows for a flexible system setup and configuration. The system was validated in three separate test scenarios to measure accuracies for 1) co-registration, 2) needle target planning in a water bath and 3) in an abdominal phantom. The co-registration accuracy averaged 0.94 ± 0.42 mm. The positioning errors ranged from 0.86 ± 0.42 to 1.19 ± 0.70 mm in the water bath setup and from 1.69 ± 0.92 to 1.96 ± 0.86 mm in the phantom. The presented results serve as a proof-of-concept and add to the current state of the art to alleviate system deployment and fast configuration for percutaneous robotic interventions.

Standardized protocol and outcome measurements for the collagen antibody-induced arthritis mouse model

The murine collagen antibody-induced arthritis (CAIA) model resembles various features of human rheumatoid arthritis and is based on the intraperitoneal or intravenous injection of autoantibodies against type II collagen. Here, we present a standardized protocol for the intraperitoneal injection of arthritis-inducing autoantibodies in mice, followed by a description of daily arthritis assessments. We then detail the steps to harvest joint and bone tissues for histological, radiological, and molecular analyses. We highlight animal welfare and 3^R considerations for experimental arthritis studies. For complete details on the use and execution of this protocol, please refer to Maleitzke et al. (2021, 2022).

Proneness to psychotic-like experiences as a basic personality trait complementing the HEXACO model-A preregistered cross-national study

The goal of the study is to investigate the relationship between the HEXACO personality model and Disintegration-representing a broad spectrum of psychotic-like experiences and behavioral tendencies (Perceptual Distortions, General Executive/Cognitive Impairment, Enhanced Awareness, Paranoia, Mania, Flattened Affect, Apathy/Depression, Somatoform Dysregulation, and Magical Thinking) that are reconceptualized as a personality trait. In this preregistered study, we predicted that the Disintegration factor would separate from HEXACO. The replicability of the factorial structures of HEXACO and Disintegration subcomponents is investigated across the three national samples (UK, Germany, and Serbia), matched on key socio-demographic variables. Exploratory Structural Equation Modeling (ESEM) is used to study the invariance of the hypothesized seven-factor structure (six HEXACO plus Disintegration). Support for the metric invariance of the seven-factor structure based on HEXACO and Disintegration subcomponents/facets across the three nations was found. The Disintegration factor lied outside the HEXACO personality space with each of its nine subcomponents. The Disintegration factor appeared to be among the most coherent and replicable of the seven across the samples and units of measurement (facets and items). A broad spectrum of psychotic-like experiences/behavioral tendencies relevant in understanding and explaining many aspects of everyday and long-term (mal)adaptations is not captured by the HEXACO model.

Differences in observed and self-reported compliance with the 5 moments for hand hygiene as a function of healthcare workers' empathy

BACKGROUND

Hand hygiene at critical time-points (as established by the WHO model 'Five moments for hand hygiene') remains the leading measure for minimising the risk of healthcare-associated infections. While many interventions have been tested to improve hand hygiene compliance (HHC) of healthcare workers (HCWs), little is known about the relation between HHC and HCW empathy.

AIM

The aim of this study was to investigate the relation between moment-specific HHC rates and HCWs' empathy, at both individual and ward levels.

METHODS

HHC data was collected via observation and self-report, staffs' empathy levels were measured using an established questionnaire. The survey was conducted on 38 wards of three tertiary-care hospitals in Germany. Observation data was obtained via in-house observations which were conducted up to eight months before or after the survey.

FINDINGS

Evidence for the expected correlation between HCW empathy and moment-specific HHC was found for both observed HHC (Moment 1: r = .483, p = .031; Moment 2: r = 588, p = .006) and self-reported HHC (Moment 1: r = .093, p = .092; Moment 2: r = .145, p = .008). In analyses of variance the critical interaction effect between empathy (i.e., lower vs. higher empathy) and designated time-point of hand hygiene (i.e., before vs. after reference task) was also significant.

CONCLUSION

HCWs' empathy should be considered as an important factor in explaining differences between moment-specific HHC rates. In consequence, empathy comes into focus not only as a crucial factor for high-quality patient care, but as an important contributor to improving HHC, too.

Novel KEL allele associated with loss of Kpb identified in a white blood donor

The importance of identifying variant alleles among blood donors is significant to the safety of transfusion for recipients. Molecular methods have become more prominent in the routine process of antigen typing donor units. Some variant antigens cannot be detected using only serologic methods. Molecular testing allows the determination of nucleotide sequences that are used to predict a phenotype. Antigens of the Kell blood group system are known for being highly immunogenic and causing adverse reactions upon antibody formation. A female white blood donor who typed Kp(b-) using serologic methods on multiple donations since 2005 was the subject of a typing discrepancy investigation. Routine genotyping using a commercial genotyping kit (HemoID DQS Panel; Agena Bioscience, San Diego, CA) predicted the donor to type Kp(a+b+). Investigation of the discrepancy between these two results identified a rare single nucleotide variant in the KEL gene at nucleotide position c.948G>T that alters amino acid residue 316 from tryptophan (Trp) to cysteine (Cys). After discovery of the novel allele, adsorption and elution studies were performed to see if there was weakened Kp^b expression. The elution studies yielded negative results, which indicated that Kp^b is not expressed. The KEL transcripts expressed by the donor were determined using cDNA analysis, and the predicted amino acid sequence of the novel allele was modeled to investigate the impact of the amino acid sequence on the structure of the KEL polypeptide. Both SWISS-MODEL and Robetta software were used to evaluate the impact of the p.Trp316Cys on the three-dimensional protein structure. There was no conformational change noted with SWISS-MODEL, whereas the Robetta software showed a significant conformational change compared with the normal Kp(b+) reference sequence. Because the donor is homozygous for variants associated with k and Js^b expression, it was not possible to determine whether the novel allele is associated with loss of Kp^b only or loss of all Kell antigens.

The impact of activating an empathic focus during COVID19 on healthcare workers motivation for hand hygiene compliance in moments serving the protection of others: a randomized controlled trial study

Aim

The "Five moments of hand hygiene" (World Health Organization 2009) can be classified into moments of hand hygiene before and after patient care. Based on research indicating that hand hygiene compliance differs with regard to moments before and after patient care, this research evaluates the effectiveness of an empathy-based intervention in motivating hand hygiene compliance with regard to moments before patient care which protect vulnerable individuals from contamination and infection.

Subjects and method

An online experiment involving 68 healthcare professionals working at a German hospital during the first wave of the COVID-19 pandemic investigates whether instructing healthcare professionals to consider consequences for others (vs for themselves) if they contracted SARS-CoV-2 promotes hand hygiene compliance referring to moments before (vs after) patient care.

Results

In the condition in which healthcare professionals considered consequences for others if they contracted SARS-CoV-2 (other-focus condition), ratings of importance increased (M = 3.49, SD = 1.30) compared to the condition in which healthcare professionals considered consequences for themselves (M = 2.68, SD = 1.24), F(1,66) = 6.87, p = .011, partη2 = .09. Participants in the other-focus condition reported more intentions to comply with "before moments" in the future (M = 3.34, SD = 1.14) compared to participants in the self-focus condition (M = 2.77, SD = 0.80), F(1,66) = 6.15, p = .016, partη2 = .09.

Conclusion

Results indicate that activating an empathic focus in the context of the current pandemic promotes perceived importance and motivation of healthcare professionals to comply with moments aiming at protecting vulnerable others.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-022-01725-z.

The role of sphingosine-1-phosphate in bone remodeling and osteoporosis

Osteoporosis is a systemic bone disease that affects more than 200 million people worldwide and is caused by the disruption of the equilibrium between osteoclastic bone resorption and osteoblastic bone formation. Sphingosine-1-phosphate (S1P) is a natural, bioactive sphingolipid that has been shown to play a major role in cardiovascular and immunological pathologies by regulating biological and cellular processes, including migration, differentiation, proliferation and survival. Recent studies also suggest a central role for S1P in bone diseases, including osteoporosis; however, the effects of S1P, particularly in bone metabolism, remain to be further elucidated. In this review, we summarize the available literature on the role of S1P in bone metabolism with a focus on osteoporosis. On the cellular level, S1P acts as an osteoclast-osteoblast coupling factor to promote osteoblast proliferation and bone formation. Moreover, the recruitment of osteoclast precursors to resorption sites is regulated by the interplay of S1P gradients and S1P receptor expression. From a clinical perspective, increasing evidence suggests that systemically elevated S1P blood levels may serve as an independent risk factor for osteoporosis-related fractures. Taken together, S1P signaling is a potential therapeutic target and may serve as a novel biomarker in patients with systemic bone disease.

Cambridge hybrid closed-loop algorithm in children and adolescents with type 1 diabetes: a multicentre 6-month randomised controlled trial

BACKGROUND

Closed-loop insulin delivery systems have the potential to address suboptimal glucose control in children and adolescents with type 1 diabetes. We compared safety and efficacy of the Cambridge hybrid closed-loop algorithm with usual care over 6 months in this population.

METHODS

In a multicentre, multinational, parallel randomised controlled trial, participants aged 6-18 years using insulin pump therapy were recruited at seven UK and five US paediatric diabetes centres. Key inclusion criteria were diagnosis of type 1 diabetes for at least 12 months, insulin pump therapy for at least 3 months, and screening HbA1c levels between 53 and 86 mmol/mol (7·0-10·0%). Using block randomisation and central randomisation software, we randomly assigned participants to either closed-loop insulin delivery (closed-loop group) or to usual care with insulin pump therapy (control group) for 6 months. Randomisation was stratified at each centre by local baseline HbA1c. The Cambridge closed-loop algorithm running on a smartphone was used with either (1) a modified Medtronic 640G pump, Medtronic Guardian 3 sensor, and Medtronic prototype phone enclosure (FlorenceM configuration), or (2) a Sooil Dana RS pump and Dexcom G6 sensor (CamAPS FX configuration). The primary endpoint was change in HbA1c at 6 months combining data from both configurations. The primary analysis was done in all randomised patients (intention to treat). Trial registration ClinicalTrials.gov, NCT02925299.

FINDINGS

Of 147 people initially screened, 133 participants (mean age 13·0 years [SD 2·8]; 57% female, 43% male) were randomly assigned to either the closed-loop group (n=65) or the control group (n=68). Mean baseline HbA1c was 8·2% (SD 0·7) in the closed-loop group and 8·3% (0·7) in the control group. At 6 months, HbA1c was lower in the closed-loop group than in the control group (between-group difference -3·5 mmol/mol (95% CI -6·5 to -0·5 [-0·32 percentage points, -0·59 to -0·04]; p=0·023). Closed-loop usage was low with FlorenceM due to failing phone enclosures (median 40% [IQR 26-53]), but consistently high with CamAPS FX (93% [88-96]), impacting efficacy. A total of 155 adverse events occurred after randomisation (67 in the closed-loop group, 88 in the control group), including seven severe hypoglycaemia events (four in the closed-loop group, three in the control group), two diabetic ketoacidosis events (both in the closed-loop group), and two non-treatment-related serious adverse events. There were 23 reportable hyperglycaemia events (11 in the closed-loop group, 12 in the control group), which did not meet criteria for diabetic ketoacidosis.

INTERPRETATION

The Cambridge hybrid closed-loop algorithm had an acceptable safety profile, and improved glycaemic control in children and adolescents with type 1 diabetes. To ensure optimal efficacy of the closed-loop system, usage needs to be consistently high, as demonstrated with CamAPS FX.

FUNDING

National Institute of Diabetes and Digestive and Kidney Diseases.

Why Do We Punish?

Abstract. We investigated whether individuals’ punishment behavior aims at compensating for inflicted harm (i.e., retribution) or at deterring the offender from committing the offense again (i.e., deterrence) and whether punishment motives depend on the punishment system. Participants ( N = 149) assigned punishment for selfish decisions in a group resource allocation task under three conditions: Open punishment (the allocator is informed about the punishment, allowing for retribution and deterrence); hidden punishment (the allocator is not informed about the punishment, precluding deterrence); and unintentional offense (decision is made by the computer not the allocator, precluding retribution and deterrence). In line with retribution motives, participants assigned more punishment under hidden punishment compared to unintentional offense and open punishment. We found these differences in punishment between punishment conditions only under centralized punishment (i.e., punishment can only be executed by one group member), but not under decentralized punishment (i.e., each group member can punish).

Procalcitonin is expressed in osteoblasts and limits bone resorption through inhibition of macrophage migration during intermittent PTH treatment

Intermittent injections of parathyroid hormone (iPTH) are applied clinically to stimulate bone formation by osteoblasts, although continuous elevation of parathyroid hormone (PTH) primarily results in increased bone resorption. Here, we identified Calca, encoding the sepsis biomarker procalcitonin (ProCT), as a novel target gene of PTH in murine osteoblasts that inhibits osteoclast formation. During iPTH treatment, mice lacking ProCT develop increased bone resorption with excessive osteoclast formation in both the long bones and axial skeleton. Mechanistically, ProCT inhibits the expression of key mediators involved in the recruitment of macrophages, representing osteoclast precursors. Accordingly, ProCT arrests macrophage migration and causes inhibition of early but not late osteoclastogenesis. In conclusion, our results reveal a potential role of osteoblast-derived ProCT in the bone microenvironment that is required to limit bone resorption during iPTH.

The calcitonin receptor protects against bone loss and excessive inflammation in collagen antibody-induced arthritis

Pharmacological application of teleost calcitonin (CT) has been shown to exert chondroprotective and anti-resorptive effects in patients with rheumatoid arthritis (RA). However, the role of endogenous CT that signals through the calcitonin receptor (CTR) remains elusive. Collagen II antibody-induced arthritis (CAIA) was stimulated in wild type (WT) and CTR-deficient (Calcr^−/−) mice. Animals were monitored over 10 or 48 days. Joint inflammation, cartilage degradation, and bone erosions were assessed by clinical arthritis score, histology, histomorphometry, gene expression analysis, and μ-computed tomography. CAIA was accompanied by elevated systemic CT levels and CTR expression in the articular cartilage. Inflammation, cartilage degradation, and systemic bone loss were more pronounced in Calcr^−/− CAIA mice. Expression of various pro-inflammatory, bone resorption, and catabolic cartilage markers were exclusively increased in Calcr^−/− CAIA mice. Endogenous CT signaling through the mammalian CTR has the potential to protect against joint inflammation, cartilage degradation, and excessive bone remodeling in experimental RA.

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CT levels are increased systemically during acute experimental RA

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CTR is primarily expressed in the superficial articular cartilage layer in CAIA

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In CAIA CTR-deficiency is associated with increased inflammation marker expression

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Bone architecture is impaired in experimental RA when CTR signaling is disrupted

Spotted Lanternfly (Hemiptera: Fulgoridae) Nymphal Dispersion Patterns and Their Influence on Field Experiments

The spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae) (White, 1845), is an invasive pest in the Mid-Atlantic region of the United States. Understanding this pest's dispersion patterns is fundamental for development of management and surveillance programs. To address this knowledge gap, we quantified spotted lanternfly nymph dispersion patterns by instar for rural and urban/suburban habitats, and we compared the number of sample units required for sticky traps and in situ visual counts to estimate population densities at several precisions. In addition, we assessed the ability of two experimental designs (completely random and randomized complete block) to detect management practices' impacts in the field. All instars typically followed an aggregated dispersion pattern. Sample size and time requirements for checking and replacing sticky traps and for conducting in situ counts were similar, but in situ counts do not require purchasing traps, installation time, or delays before treatment, and do not remove insects. Although the cost for using in situ counts is likely less than for sticky traps, early instar spotted lanternfly nymph populations are harder to visually detect than later instars because of their small size, which may negate any cost advantage when treatments are applied early. In general, using a randomized complete block design resulted in higher statistical power than a completely random design, allowing detection of proportional population reductions of 10-20% less with equal replication. Studies aiming to evaluate treatments that reduce spotted lanternfly numbers by less than 60% will require researchers to evaluate the feasibility of using the required large sample sizes.

Hygiene-Eliciting Brood Semiochemicals as a Tool for Assaying Honey Bee (Hymenoptera: Apidae) Colony Resistance to Varroa (Mesostigmata: Varroidae)

Despite numerous interventions, the ectoparasitic mite Varroa (Varroa destructor Anderson and Trueman [Mesostigmata: Varroidae]) and the pathogens it vectors remain a primary threat to honey bee (Apis mellifera Linnaeus [Hymenoptera: Apidae]) health. Hygienic behavior, the ability to detect, uncap, and remove unhealthy brood from the colony, has been bred for selectively for over two decades and continues to be a promising avenue for improved Varroa management. Although hygienic behavior is expressed more in Varroa-resistant colonies, hygiene does not always confer resistance to Varroa. Additionally, existing Varroa resistance selection methods trade efficacy for efficiency, because those achieving the highest levels of Varroa resistance can be time-consuming, and thus expensive and impractical for apicultural use. Here, we tested the hypothesis that hygienic response to a mixture of semiochemicals associated with Varroa-infested honey bee brood can serve as an improved tool for predicting colony-level Varroa resistance. In support of our hypothesis, we demonstrated that a mixture of the compounds (Z)-10-tritriacontene, (Z)-8-hentriacontene, (Z)-8-heptadecene, and (Z)-6-pentadecene triggers hygienic behavior in a two-hour assay, and that high-performing colonies (hygienic response to ≥60% of treated cells) have significantly lower Varroa infestations, remove significantly more introduced Varroa, and are significantly more likely to survive the winter compared to low-performing colonies (hygienic response to <60% of treated cells). We discuss the relative efficacy and efficiency of this assay for facilitating apiary management decisions and selection of Varroa-resistant honey bees, as well as the relevance of these findings to honey bee health, pollination services, and social insect communication.

Future Perspectives in Spinal Cord Repair: Brain as Saviour? TSCI with Concurrent TBI: Pathophysiological Interaction and Impact on MSC Treatment

Traumatic spinal cord injury (TSCI), commonly caused by high energy trauma in young active patients, is frequently accompanied by traumatic brain injury (TBI). Although combined trauma results in inferior clinical outcomes and a higher mortality rate, the understanding of the pathophysiological interaction of co-occurring TSCI and TBI remains limited. This review provides a detailed overview of the local and systemic alterations due to TSCI and TBI, which severely affect the autonomic and sensory nervous system, immune response, the blood-brain and spinal cord barrier, local perfusion, endocrine homeostasis, posttraumatic metabolism, and circadian rhythm. Because currently developed mesenchymal stem cell (MSC)-based therapeutic strategies for TSCI provide only mild benefit, this review raises awareness of the impact of TSCI-TBI interaction on TSCI pathophysiology and MSC treatment. Therefore, we propose that unravelling the underlying pathophysiology of TSCI with concomitant TBI will reveal promising pharmacological targets and therapeutic strategies for regenerative therapies, further improving MSC therapy.

The Digital Twin: Modular Model-Based Approach to Personalized Medicine

To overcome obstacles and complexity of decision making in clinical oncology, we propose an integrated clinical decision support approach; the Digital Twin. We analyse the reasons for frustration in applying clinical decision support and provide a multi-levelled approach to implementing a flexible system to support and strengthen clinical decisions. Describing medical patterns and contexts with Resource Description Framework (RDF) allows for standardised way of connecting medical knowledge and processing modules. Having flexible web-based interfaces integrated a multitude of heterogeneous data processing systems to either make clinical data available altogether, or provide calculations and assessments. Transition of the Digital Twin to clinical practice promises effective assistance and safer clinical decisions.

An Integrated Approach to Testing and Assessment to Support Grouping and Read-Across of Nanomaterials After Inhalation Exposure

Introduction: Here, we describe the generation of hypotheses for grouping nanoforms (NFs) after inhalation exposure and the tailored Integrated Approaches to Testing and Assessment (IATA) with which each specific hypothesis can be tested. This is part of a state-of-the-art framework to support the hypothesis-driven grouping and read-across of NFs, as developed by the EU-funded Horizon 2020 project GRACIOUS.

Development of Grouping Hypotheses and IATA: Respirable NFs, depending on their physicochemical properties, may dissolve either in lung lining fluid or in acidic lysosomal fluid after uptake by cells. Alternatively, NFs may also persist in particulate form. Dissolution in the lung is, therefore, a decisive factor for the toxicokinetics of NFs. This has led to the development of four hypotheses, broadly grouping NFs as instantaneous, quickly, gradually, and very slowly dissolving NFs. For instantaneously dissolving NFs, hazard information can be derived by read-across from the ions. For quickly dissolving particles, as accumulation of particles is not expected, ion toxicity will drive the toxic profile. However, the particle aspect influences the location of the ion release. For gradually dissolving and very slowly dissolving NFs, particle-driven toxicity is of concern. These NFs may be grouped by their reactivity and inflammation potency. The hypotheses are substantiated by a tailored IATA, which describes the minimum information and laboratory assessments of NFs under investigation required to justify grouping.

Conclusion: The GRACIOUS hypotheses and tailored IATA for respiratory toxicity of inhaled NFs can be used to support decision making regarding Safe(r)-by-Design product development or adoption of precautionary measures to mitigate potential risks. It can also be used to support read-across of adverse effects such as pulmonary inflammation and subsequent downstream effects such as lung fibrosis and lung tumor formation after long-term exposure.

Influence of pregnancy and non-fasting conditions on the plasma metabolome in a rat prenatal toxicity study

The current parameters for determining maternal toxicity (e.g. clinical signs, food consumption, body weight development) lack specificity and may underestimate the extent of effects of test compounds on the dams. Previous reports have highlighted the use of plasma metabolomics for an improved and mechanism-based identification of maternal toxicity. To establish metabolite profiles of healthy pregnancies and evaluate the influence of food consumption as a confounding factor, metabolite profiling of rat plasma was performed by gas- and liquid-chromatography-tandem mass spectrometry techniques. Metabolite changes in response to pregnancy, food consumption prior to blood sampling (non-fasting) as well as the interaction of both conditions were studied. In dams, both conditions, non-fasting and pregnancy, had a marked influence on the plasma metabolome and resulted in distinct individual patterns of changed metabolites. Non-fasting was characterized by increased plasma concentrations of amino acids and diet related compounds and lower levels of ketone bodies. The metabolic profile of pregnant rats was characterized by lower amino acids and glucose levels and higher concentrations of plasma fatty acids, triglycerides and hormones, capturing the normal biochemical changes undergone during pregnancy. The establishment of metabolic profiles of pregnant non-fasted rats serves as a baseline to create metabolic fingerprints for prenatal and maternal toxicity studies.

Enzyme replacement therapy in mice lacking arylsulfatase B targets bone-remodeling cells, but not chondrocytes

Mucopolysaccharidosis type VI (MPS-VI), caused by mutational inactivation of the glycosaminoglycan-degrading enzyme arylsulfatase B (Arsb), is a lysosomal storage disorder primarily affecting the skeleton. We have previously reported that Arsb-deficient mice display high trabecular bone mass and impaired skeletal growth. In the present study, we treated them by weekly injection of recombinant human ARSB (rhARSB) to analyze the impact of enzyme replacement therapy (ERT) on skeletal growth and bone remodeling. We found that all bone-remodeling abnormalities of Arsb-deficient mice were prevented by ERT, whereas chondrocyte defects were not. Likewise, histologic analysis of the surgically removed femoral head from an ERT-treated MPS-VI patient revealed that only chondrocytes were pathologically affected. Remarkably, a side-by-side comparison with other cell types demonstrated that chondrocytes have substantially reduced capacity to endocytose rhARSB, together with low expression of the mannose receptor. We finally took advantage of Arsb-deficient mice to establish quantification of chondroitin sulfation for treatment monitoring. Our data demonstrate that bone-remodeling cell types are accessible to systemically delivered rhARSB, whereas the uptake into chondrocytes is inefficient.