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Reduced skeletal loading associated with many conditions, such as neuromuscular injuries, can lead to bone fragility and may threaten the success of implant therapy. Our group has developed a botulinum toxin A (botox) injection model to imitate disease-reduced skeletal loading and reported that botox dramatically impaired the bone formation and osseointegration of titanium implants. Semaphorin 3A (sema3A) is an osteoprotective factor that increases bone formation and inhibits bone resorption, indicating its potential therapeutic role in improving osseointegration in vivo. We first evaluated the sema3A effect on whole bone morphology following botox injections by delivering sema3A via injection. We then evaluated the sema3A effect on the osseointegration of titanium implants with two different surface topographies by delivering sema3A to cortical bone defect sites prepared for implant insertion and above the implants after insertion using a copper-free click hydrogel that polymerizes rapidly in situ. Implants had hydrophobic smooth surfaces (PT) or multiscale biomimetic micro/nano topography (SLAnano). Sema3A rescued the botox-impaired bone formation. Furthermore, biomimetic Ti implants improved the bone-to-implant contact (BIC) and mechanical properties of the integrated bone in the botox-treated rats, which sema3A enhanced. This study demonstrated the value of biomimetic approaches combining multiscale topography and biologics in improving the clinical outcomes of implant therapy.

Refereed/Peer-reviewed The genetic basis of the predisposition for Down Syndrome (DS) patients to develop cytokine receptor-like factor 2 rearranged (CRLF2r) acute lymphoblastic leukemia (ALL) is currently unknown. Genes located on chromosome 21 and expressed in hematopoietic cells are likely candidates for investigation of CRLF2r DS-ALL pathogenesis. We explored the high-mobility group nucleosome-binding protein 1 (HMGN1), located in the DS critical region, in an inducible CRISPR/Cas9 knockout (KO) xenograft model to assess the effect of HMGN1 loss of function on the leukemic burden. We demonstrated HMGN1 KO-mitigated leukemic phenotypes including hepatosplenomegaly, thrombocytopenia, and anemia, commonly observed in leukemia patients, and significantly increased survival in vivo. HMGN1 overexpression in murine stem cells and Ba/F3 cells in vitro, in combination with P2RY8-CRLF2, resulted in cytokine-independent transformation and upregulation of cell signaling pathways associated with leukemic development. Finally, in vitro screening demonstrated successful targeting of P2RY8-CRLF2 and HMGN1 co-expressing cell lines and patient samples with fedratinib (JAK2 inhibitor), and GSK-J4 (demethylase inhibitor) in combination. Together, these data provide critical insight into the development and persistence of CRLF2r DS-ALL and identify HMGN1 as a potential therapeutic target to improve outcomes and reduce toxicity in this high-risk cohort of young patients.

Rearrangements of Janus kinase 2 (JAK2r) form a subtype of acute lymphoblastic leukaemia (ALL) associated with poor patient outcomes. We present a high-risk case of B-cell ALL (B-ALL) where retrospective mRNA sequencing identified a novel GOLGA4-JAK2 fusion gene. Expression of GOLGA4-JAK2 in murine pro-B cells promoted factor-independent growth, implicating GOLGA4-JAK2 as an oncogenic driver. Cells expressing GOLGA4-JAK2 demonstrated constitutive activation of JAK/STAT signalling and were sensitive to JAK inhibitors. This study contributes to the diverse collection of JAK2 fusion genes identified in B-ALL and supports the incorporation of JAK inhibitors into treatment strategies to improve outcomes for this subtype.

Since its first introduction by Martin and colleagues (1993) and with further revisions by Sterne et al (1996), the submental artery flap (SMAF) has proven to be an effective, reliable, safe, and valuable option in head, neck, and facial reconstructive surgeries. The SMAF utilizes a long pedicle based on the submental artery, a branch of the facial artery, which provides good reach to the lower two-thirds of the face with excellent cosmetic outcomes. It also maintains a good skin color match for facial and cervical defects with a mostly hidden donor site scar (in the majority of cases the donor site can be primarily closed after raising the flap). Although the use of the SMAF is associated with high patient and surgeon satisfaction along with low rates of complications, disadvantages including flap thickness and the hair-bearing nature of the submental skin, which may be problematic for coverage of orofacial defects, especially in male patients. Although it has been almost 30 years since its introduction, and the SMAF has been successfully used in over 500 reported cases of pediatric and adult patients, a comprehensive review of the different aspects of the SMAF is lacking in the medical literature.

Ruxolitinib (rux) Phase II clinical trials are underway for the treatment of high-riskJAK2-rearranged (JAK2r) B-cell acute lymphoblastic leukemia (B-ALL). Treatment resistance to targeted inhibitors in other settings is common; elucidating potential mechanisms of rux resistance inJAK2r B-ALL will enable development of therapeutic strategies to overcome or avert resistance. We generated a murine pro-B cell model ofATF7IP-JAK2with acquired resistance to multiple type-I JAK inhibitors. Resistance was associated with mutations within theJAK2ATP/rux binding site, including aJAK2p.G993A mutation. Using in vitro models ofJAK2r B-ALL,JAK2p.G993A conferred resistance to six type-I JAK inhibitors and the type-II JAK inhibitor, CHZ-868. Using computational modeling, we postulate thatJAK2p.G993A enabled JAK2 activation in the presence of drug binding through a unique resistance mechanism that modulates the mobility of the conserved JAK2 activation loop. This study highlights the importance of monitoring mutation emergence and may inform future drug design and the development of therapeutic strategies for this high-risk patient cohort.

Transfection of chondrocytes with microRNA-451(miR-451), present in growth zone cartilage of the growth plate, upregulates production of enzymes association with extracellular matrix degradation. miR-451 is also present in articular cartilage and exacerbates IL-1β effects in articular chondrocytes. Moreover, when osteoarthritis (OA) was induced in Sprague Dawley rats via bilateral anterior cruciate ligament transection (ACLT), miR-451 expression was increased in OA cartilage compared to control, suggesting its inhibition might be used to prevent or treat OA. To examine the prophylactic and therapeutic potential of inhibiting miR-451, we evaluated treatment with miR-451 power inhibitor (451-PI) at the onset of joint trauma and treatment after OA had developed. The prophylactic animal cohort received twice-weekly intra-articular injections of either 451-PI or a negative control (NC-PI) beginning on post-surgical day 3. OA was allowed to develop for 24 days in the therapeutic cohort before beginning injections. All rats were killed on day 45. Micro-CT, histomorphometrics, OARSI scoring, and muscle force testing were performed on samples. 451-PI mitigated OA progression compared to NC-PI limbs in the prophylactic cohort based on histomorphometric analysis and OARSI scoring, but no differences were detected by micro-CT. 451-PI treatment beginning 24 days post-surgery was not able to reduce OA severity. Prophylactic administration of 451-PI mitigates OA progression in a post-trauma ACLT rat model supporting its potential to prevent OA development following an ACLT injury clinically.

Volumetric muscle loss (VML) is the acute loss of muscle mass due to trauma. Such injuries occur primarily in the extremities and are debilitating, as there is no clinical treatment to restore muscle function. Pro-inflammatory advanced glycation end-products (AGEs) and the soluble receptor for advanced glycation end-products (RAGE) are known to increase in acute trauma patient’s serum and are correlated with increased injury severity. However, it is unclear whether AGEs and RAGE increase in muscle post-trauma. To test this, we used decellularized muscle matrix (DMM), a pro-myogenic, non-immunogenic extracellular matrix biomaterial derived from skeletal muscle. We delivered adipose-derived stromal cells (ASCs) and primary myoblasts to support myogenesis and immunomodulation (N = 8 rats/group). DMM non-seeded and seeded grafts were compared to empty defect and sham controls. Then, 56 days after surgery muscle force was assessed, histology characterized, and protein levels for AGEs, RAGE, p38 MAPK, and myosin heavy chains were measured. Overall, our data showed improved muscle regeneration in ASC-treated injury sites and a regulation of RAGE and p38 MAPK signaling, while myoblast-treated injuries resulted in minor improvements. Taken together, these results suggested that ASCs combined with DMM provides a pro-myogenic microenvironment with immunomodulatory capabilities and indicates further exploration of RAGE signaling in VML.

IntroductionExertional rhabdomyolysis is a syndrome of muscle breakdown following exercise. This study describes laboratory and demographic trends of service members hospitalised for exertional rhabdomyolysis and examines the relationships with heat illness.MethodsWe queried the US Armed Forces Health Surveillance Center’s Defence Medical Epidemiology Database for hospitalised cases of rhabdomyolysis associated with physical exertion from January 2010 July 2013. Descriptive statistics reported means and medians of initial, peak and minimal levels of creatine kinase (CK). Correlations explored the relationship between CK, creatinine, length of hospital stay (LOS) and demographic data.ResultsWe analysed 321 hospitalised cases of exertional rhabdomyolysis. 193 (60.1%) cases were associated with heat; 104 (32.4%) were not associated with heat; and 24 (7.5%) were classified as medical-associated exertional rhabdomyolysis. Initial, maximum and minimal CK levels were significantly lower in heat cases: CK=6528 U/L vs 19 247 U/L, p=0.001; 13 146 U/L vs 22 201 U/L, p=0.03; and 3618 U/L vs 10 321 U/L, p=0.023) respectively, compared with cases of rhabdomyolysis with exertion alone. Median LOS was 2 days (range=0–25). In the rhabdomyolysis with exertion alone group and the rhabdomyolysis with heat group, LOS was moderately correlated with maximal CK (Spearman’s ρ=0.52, pConclusionMost hospitalisations for exertional rhabdomyolysis were associated with heat illness and presented with lower CK levels than cases without associated heat illness. These data add evidence that rhabdomyolysis with heat illness is a different entity than rhabdomyolysis with exertion alone. Differentiating exertional rhabdomyolysis with and without heat should inform future research on rhabdomyolysis prognosis and clinical management.

Background Proximal junctional kyphosis (PJK) is a common postoperative complication after adult spinal deformity (ASD) surgery and may manifest with neurological decline, worsening spinal deformity, and spinal instability, which warrant reoperation. Rates of PJK may be as high as 69.4% after ASD surgery. Objective To evaluate the efficacy of junctional tethers for PJK prophylaxis after multilevel instrumented surgery for ASD with minimum 2-yr follow-up. Methods Single-center retrospective analysis of adult patients (age ≥18 yr) who underwent ASD surgery with index operations performed between November 2010 and June 2016 and achieved minimum 2-yr follow-up. Patients with ASD were subdivided into 3 treatment cohorts based on institutional protocol: no tether (NT), polyethylene tether-only (TO), and tether with crosslink (TC). PJK was defined as a proximal junctional angle (PJA) >10° and 10° greater than the corresponding preoperative measurement. Patient demographics, operative details, standard radiographic scoliosis measurements (including PJA and assessment of PJK), and complications were analyzed. Results Of 184 patients, 146 (79.3%) achieved minimum 2-yr follow-up (mean = 45 mo; mean age = 67 yr; 67.8% women). PJK rates reported for the NT, TO, and TC cohorts were 60.7% (37/61), 35.7% (15/42), and 23.3% (10/43), respectively. PJK rates among TC patients were significantly lower than NT (P = .01601). Conclusion Junctional tethers with crosslink significantly reduced the incidence of PJK and revisions for PJK among ASD patients treated with long-segment posterior instrumented fusions who achieved minimum 2-yr follow-up.

Matrix vesicles (MVs) are extracellular organelles produced by growth plate cartilage cells in a zone-specific manner. MVs are similar in size to exosomes, but they are tethered to the extracellular matrix (ECM) via integrins. Originally associated with matrix calcification, studies now show that they contain matrix processing enzymes and microRNA that are specific to their zone of maturation. MVs produced by costochondral cartilage resting zone (RC) chondrocytes are enriched in microRNA 503 whereas those produced by growth zone (GC) chondrocytes are enriched in microRNA 122. MVs are packaged by chondrocytes under hormonal and factor regulation and release of their contents into the ECM is also under hormonal control, suggesting that their microRNA might have a regulatory role in growth plate proliferation and maturation. To test this, we selected a subset of these enriched microRNAs and transfected synthetic mimics back into RC and GC cells. Transfecting growth plate chondrocytes with select microRNA produced a broad range of phenotypic responses indicating that MV-based microRNAs are involved in the regulation of these cells. Specifically, microRNA 122 drives both RC and GC cells toward a proliferative phenotype, stabilizes the matrix and inhibits differentiation whereas microRNA 22 exerts control over regulatory factor production. This study demonstrates the strong regulatory capability possessed by unique MV enriched microRNAs on growth plate chondrocytes and their potential for use as therapeutic agents.

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, arising from immature lymphocytes that show uncontrolled proliferation and arrested differentiation. Genomic alterations affecting Janus kinase 2 (JAK2) correlate with some of the poorest outcomes within the Philadelphia-like subtype of ALL. Given the success of kinase inhibitors in the treatment of chronic myeloid leukemia, the discovery of activating JAK2 point mutations and JAK2 fusion genes in ALL, was a breakthrough for potential targeted therapies. However, the molecular mechanisms by which these alterations activate JAK2 and promote downstream signaling is poorly understood. Furthermore, as clinical data regarding the limitations of approved JAK inhibitors in myeloproliferative disorders matures, there is a growing awareness of the need for alternative precision medicine approaches for specific JAK2 lesions. This review focuses on the molecular mechanisms behind ALL-associated JAK2 mutations and JAK2 fusion genes, known and potential causes of JAK-inhibitor resistance, and how JAK2 alterations could be targeted using alternative and novel rationally designed therapies to guide precision medicine approaches for these high-risk subtypes of ALL.

Each person has a deep, unconscious sense of what feels like home to them. Formed in one’s earliest experiences, the term home is another way to describe what psychoanalyst Christopher Bollas calls the “unthought known.” One’s unthought known creates a longing in one and motivates one to search for home—to recreate the earliest childhood experiences that feel like home. Theologically, we might say that the longing for home is, in part, the longing for God, wholeness, and what is Good. Homing, or the process of recreating home, is not a neutral process, however. Rather, it is one fraught with political, economic, and psychological challenges born of exclusion and injustice. Pastoral practitioners can facilitate processes of mourning, witness, agency, and change.

Study Design: Systematic Review. Objectives: To review the literature surrounding the cost-effectiveness of implanting spinal cord stimulators for failed back surgery syndrome. Methods: A systematic review was conducted inclusive of all publications in the Medline database and Cochrane CENTRAL trials register within the last 10 years (English language only) assessing the cost-effectiveness of Spinal Cord Stimulator device implantation (SCSdi) in patients with previous lumbar fusion surgery. Results: The majority of reviewed publications that analyzed cost-effectiveness of SCSdi compared to conventional medical management (CMM) or re-operation in patients with failed back surgery syndrome (FBSS) showed an overall increase in direct medical costs; these increased costs were found in nearly all cases to be offset by significant improvements in patient quality of life. The cost required to achieve these increases in quality adjusted life years (QALY) falls well below $25 000/QALY, a conservative estimate of willingness to pay. Conclusions: The data suggest that SCSdi provides both superior outcomes and a lower incremental cost: effectiveness ratio (ICER) compared to CMM and/or re-operation in patients with FBSS. These findings are in spite of the fact that the majority of studies reviewed were agnostic to the type of device or innervation utilized in SCSdi. Newer devices utilizing burst or higher frequency stimulation have demonstrated their superiority over traditional SCSdi via randomized clinical trials and may provide lower ICERs.

Children with neurofibromatosis have a higher risk of developing juvenile myelomonocytic leukemia and acute myeloid leukemia, but rarely develop B-cell acute lymphoblastic leukemia (B-ALL). Through in-vitro modeling, a novel NF1 p.L2467 frameshift (fs) mutation identified in a relapsed/refractory Ph-like B-ALL patient with neurofibromatosis demonstrated cytokine independence and increased RAS signaling, indicative of leukemic transformation. Furthermore, these cells were sensitive to the MEK inhibitors trametinib and mirdametinib. Bi-allelic NF1 loss of function may be a contributing factor to relapse and with sensitivity to MEK inhibitors, suggests a novel precision medicine target in the setting of neurofibromatosis patients with B-ALL.

The objectives of this study were to i) describe Escherichia coli and Salmonella isolates; ii) investigate the temporal trends in antimicrobial resistance (AMR) profiles; and iii) evaluate the impact of season and age on these AMR profiles from diagnostic and post-mortem samples in Ontario calves ≤ 2-months-old submitted from 2007 to 2020 to the Animal Health Laboratory in Guelph, Ontario, Canada. Antimicrobial susceptibility testing results were measured by the Kirby-Bauer disk diffusion method. A total of 1291 isolates with AMR profiles were obtained from calves, with E. coli (n = 434) and Salmonella (n = 378) being the most common bacteria characterized for AMR. For E. coli, 79% of isolates tested showed a positive result in F5/K99, whereas for Salmonella isolates, S. Typhimurium (33%) and S. Dublin (22%) were the 2 most common serotypes identified. Multivariable logistic regression models were built to evaluate AMR profiles for E. coli (n = 414) and Salmonella (n = 357) to each antimicrobial tested. Most E. coli isolates (91%) and Salmonella isolates (97%) were resistant to at least one of the antimicrobials tested. In general, E. coli and Salmonella had higher odds of resistance in calves aged ≥ 2 wk compared to 1-week-old calves, and little difference was seen in the level of resistance over the years observed or between seasons in most of the antimicrobials tested. Prospective research should investigate potential risk factors for the development of AMR in calves examples being antimicrobial use and farm management practices.

Barbara J. McClure, Susan L. Heatley, Jacqueline Rehn, James Breen, Rosemary Sutton, Timothy P. Hughes, Ram Suppiah, Tamas Revesz, Michael Osborn, Daniel White, David T. Yeung, Deborah L. White

Alerce (Fitzroya cupressoides (Mol.) Johnst.) and Guaitecas cypress (Pilgerodendron uviferum (Don) Florin) are two of the three closely-related species of conifers in the Cupressaceae that are endemic to southern Chile and Argentina. Both are listed in Appendix I of the Convention on International Trade in Endangered Species of Fauna and Flora (CITES). The presence or absence of nodular (conspicuously pitted) end walls in the parenchyma cells provide good diagnostic characters to separate the two species wood anatomically, but the latter is sometimes difficult to distinguish. Therefore, a collaborative project was designed to study the chemical-molecular expression of these species by analyzing the heartwood using DART TOFMS (Direct Analysis in Real-Time (DART) Time-of-Flight Mass Spectrometry (TOFMS). This study compares the anatomical features of heartwood for both species and demonstrates that anatomy in conjunction with chemistry can separate them. DART TOFMS analysis combined with PCA was able to unequivocally determine taxonomic source with a statistical certainty of 99%. The mass spectra results obtained from heartwood demonstrated that identification is feasible after a few seconds, using a very small sample. DART TOFMS is a robust tool for reliable species identification and is useful to identify the taxonomic source of finished products or timber that are suspected of being illegally harvested.

Allergic contact dermatitis (ACD) is a prevalent and poorly controlled inflammatory disease caused by skin infiltration of T cells and granulocytes. The beta common (βc) cytokines GM-CSF, IL-3, and IL-5 are powerful regulators of granulocyte function that signal through their common receptor subunit βc, a property that has made βc an attractive target to simultaneously inhibit these cytokines. However, the species specificity of βc has precluded testing of inhibitors of human βc in mouse models. To overcome this problem, we developed a human βc receptor transgenic mouse strain with a hematopoietic cell‒specific expression of human βc instead of mouse βc. Human βc receptor transgenic cells responded to mouse GM-CSF and IL-5 but not to IL-3 in vitro and developed tissue pathology and cellular inflammation comparable with those in wild-type mice in a model of ACD. Similarly, Il3–/– mice developed ACD pathology comparable with that of wild-type mice. Importantly, the blocking anti–human βc antibody CSL311 strongly suppressed ear pinna thickening and histopathological changes typical of ACD and reduced accumulation of neutrophils, mast cells, and eosinophils in the skin. These results show that GM-CSF and IL-5 but not IL-3 are major mediators of ACD and define the human βc receptor transgenic mouse as a unique platform to test the inhibitors of βc in vivo. Refereed/Peer-reviewed