19 research outputs found
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Reporters of TCR signaling identify arthritogenic T cells in murine and human autoimmune arthritis.
How pathogenic cluster of differentiation 4 (CD4) T cells in rheumatoid arthritis (RA) develop remains poorly understood. We used Nur77-a marker of T cell antigen receptor (TCR) signaling-to identify antigen-activated CD4 T cells in the SKG mouse model of autoimmune arthritis and in patients with RA. Using a fluorescent reporter of Nur77 expression in SKG mice, we found that higher levels of Nur77-eGFP in SKG CD4 T cells marked their autoreactivity, arthritogenic potential, and ability to more readily differentiate into interleukin-17 (IL-17)-producing cells. The T cells with increased autoreactivity, nonetheless had diminished ex vivo inducible TCR signaling, perhaps reflective of adaptive inhibitory mechanisms induced by chronic autoantigen exposure in vivo. The enhanced autoreactivity was associated with up-regulation of IL-6 cytokine signaling machinery, which might be attributable, in part, to a reduced amount of expression of suppressor of cytokine signaling 3 (SOCS3)-a key negative regulator of IL-6 signaling. As a result, the more autoreactive GFPhi CD4 T cells from SKGNur mice were hyperresponsive to IL-6 receptor signaling. Consistent with findings from SKGNur mice, SOCS3 expression was similarly down-regulated in RA synovium. This suggests that despite impaired TCR signaling, autoreactive T cells exposed to chronic antigen stimulation exhibit heightened sensitivity to IL-6, which contributes to the arthritogenicity in SKG mice, and perhaps in patients with RA
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Breast Radiation Exposure in Female Orthopaedic Surgeons.
BackgroundBreast cancer prevalence is higher among female orthopaedic surgeons compared with U.S. women. The most common breast cancer site, the upper outer quadrant (UOQ), may not be adequately shielded from intraoperative radiation. Factors associated with higher breast radiation exposure (protective apron size and type, surgeon position, and C-arm position) have yet to be established.MethodsAn anthropomorphic torso phantom, simulating the female surgeon, was placed adjacent to a standard operating table. Dosimeters were placed over the UOQ and lower inner quadrant (LIQ) of the breast, bilaterally. Scatter radiation dose-equivalent rates were measured during continuous fluoroscopy to a pelvic phantom (simulating the patient). Four apron sizes (small, medium, large, and extra-large), 2 apron types (cross-back and vest), 2 surgeon positions (facing the table and 90° to the table), and 2 C-arm positions (anteroposterior and cross-table lateral projection) were tested.ResultsThe median dose-equivalent rate of scatter radiation to the UOQ (0.40 mrem/hr) was higher than that to the LIQ of the breast (0.06 mrem/hr) across all testing, although this was not statistically significant (p = 0.05). The cross-back aprons provided higher protection to the LIQ compared with the vests (p < 0.05). Lead protection in sizes that were too small or too large for the torso had higher breast radiation dose-equivalent rates. C-arm cross-table lateral projection was associated with higher breast radiation exposure (0.98 mrem/hr) compared with anteroposterior projection (0.13 mrem/hr) (p < 0.001).ConclusionsBreast radiation exposure is higher in a C-arm lateral projection compared with an anteroposterior projection. Higher dose-equivalent rates were observed for the UOQ compared with the LIQ of the breast and for aprons that were too small or too large, although these differences did not reach significance. Factors that may reduce radiation exposure include lead protection of appropriate size and distancing the axilla from the patient and x-ray tube.Clinical relevanceIncreased breast cancer prevalence has been reported for female orthopaedic surgeons. The UOQ of the breast may be at risk for intraoperative radiation exposure. Methods of reducing exposure are warranted
Recommended from our members
Breast Radiation Exposure in Female Orthopaedic Surgeons.
BackgroundBreast cancer prevalence is higher among female orthopaedic surgeons compared with U.S. women. The most common breast cancer site, the upper outer quadrant (UOQ), may not be adequately shielded from intraoperative radiation. Factors associated with higher breast radiation exposure (protective apron size and type, surgeon position, and C-arm position) have yet to be established.MethodsAn anthropomorphic torso phantom, simulating the female surgeon, was placed adjacent to a standard operating table. Dosimeters were placed over the UOQ and lower inner quadrant (LIQ) of the breast, bilaterally. Scatter radiation dose-equivalent rates were measured during continuous fluoroscopy to a pelvic phantom (simulating the patient). Four apron sizes (small, medium, large, and extra-large), 2 apron types (cross-back and vest), 2 surgeon positions (facing the table and 90° to the table), and 2 C-arm positions (anteroposterior and cross-table lateral projection) were tested.ResultsThe median dose-equivalent rate of scatter radiation to the UOQ (0.40 mrem/hr) was higher than that to the LIQ of the breast (0.06 mrem/hr) across all testing, although this was not statistically significant (p = 0.05). The cross-back aprons provided higher protection to the LIQ compared with the vests (p < 0.05). Lead protection in sizes that were too small or too large for the torso had higher breast radiation dose-equivalent rates. C-arm cross-table lateral projection was associated with higher breast radiation exposure (0.98 mrem/hr) compared with anteroposterior projection (0.13 mrem/hr) (p < 0.001).ConclusionsBreast radiation exposure is higher in a C-arm lateral projection compared with an anteroposterior projection. Higher dose-equivalent rates were observed for the UOQ compared with the LIQ of the breast and for aprons that were too small or too large, although these differences did not reach significance. Factors that may reduce radiation exposure include lead protection of appropriate size and distancing the axilla from the patient and x-ray tube.Clinical relevanceIncreased breast cancer prevalence has been reported for female orthopaedic surgeons. The UOQ of the breast may be at risk for intraoperative radiation exposure. Methods of reducing exposure are warranted
AOA Critical Issues: Gender Justice in Academic Medicine: What It Might Look Like in Orthopaedic Surgery
As the number of women entering medicine has increased, so has the number of women entering orthopaedics; however, many orthopaedic programs struggle to create an equitable space for women, particularly in leadership. Struggles experienced by women include sexual harassment and gender bias, lack of visibility, lack of well-being, disproportionate family care responsibilities, and lack of flexibility in the criteria for promotions. Historically, sexual harassment and bias has been a problem faced by women physicians, and often the harassment continues even when the issue has been reported; many women find that reporting it results in negative consequences for their career and training. Additionally, throughout medical training, women are less exposed to orthopaedics and lack the mentorship that is given to their colleagues who are men. The late exposure and lack of support prevent women from entering and advancing in orthopaedic training. Typical surgery culture can also result in women orthopaedic surgeons avoiding help for mental wellness. Improving well-being culture requires systemic changes. Finally, women in academics perceive decreased equality in promotional considerations and face leadership that already lacks representation of women. This paper presents solutions to assist in developing equitable work environments for all academic clinicians
Strategies for Deficit Recovery for the Orthopaedic Service Line: Lessons Learned from the COVID-19 Pandemic: AOA Critical Issues Symposium
ABSTRACT: The COVID-19 pandemic and the mandated cessation of surgical procedures for a substantial portion of the 2020 year placed tremendous strain, both clinically and financially, on the health-care system in the United States. As a surgical specialty that accounts for nearly a quarter of all hospital net income, the revenue recovery of orthopaedic service lines (OSLs) is of particular importance to the financial recovery of their broader health-care institutions. In this American Orthopaedic Association (AOA) symposium report, the OSL leaders from 4 major academic medical institutions explain and reflect on their approaches to address their revenue deficits. Cost-reduction strategies, such as tightening budgets, adopting remote-work models, and limiting costs of human capital, were vital to stabilizing departmental finances at the onset of the pandemic, while strategies that focused on expanding surgical volume, such as those that improve efficiency in clinical and surgical settings, were important in growing revenue once elective procedures resumed. Institutional policy, payer administrative procedures, and the overall context of an ongoing public health crisis all placed limitations on recovery efforts, but engaging relevant stakeholders and working with available resources helped OSLs overcome these limitations. Due to clear strategic actions that were taken to address their deficits, each OSL represented in this AOA symposium saw substantial improvement in its year-end financial performance compared with its financial status at the end of the period of mandatory cessation of elective surgical cases
Recommended from our members
Reporters of TCR signaling identify arthritogenic T cells in murine and human autoimmune arthritis.
How pathogenic cluster of differentiation 4 (CD4) T cells in rheumatoid arthritis (RA) develop remains poorly understood. We used Nur77-a marker of T cell antigen receptor (TCR) signaling-to identify antigen-activated CD4 T cells in the SKG mouse model of autoimmune arthritis and in patients with RA. Using a fluorescent reporter of Nur77 expression in SKG mice, we found that higher levels of Nur77-eGFP in SKG CD4 T cells marked their autoreactivity, arthritogenic potential, and ability to more readily differentiate into interleukin-17 (IL-17)-producing cells. The T cells with increased autoreactivity, nonetheless had diminished ex vivo inducible TCR signaling, perhaps reflective of adaptive inhibitory mechanisms induced by chronic autoantigen exposure in vivo. The enhanced autoreactivity was associated with up-regulation of IL-6 cytokine signaling machinery, which might be attributable, in part, to a reduced amount of expression of suppressor of cytokine signaling 3 (SOCS3)-a key negative regulator of IL-6 signaling. As a result, the more autoreactive GFPhi CD4 T cells from SKGNur mice were hyperresponsive to IL-6 receptor signaling. Consistent with findings from SKGNur mice, SOCS3 expression was similarly down-regulated in RA synovium. This suggests that despite impaired TCR signaling, autoreactive T cells exposed to chronic antigen stimulation exhibit heightened sensitivity to IL-6, which contributes to the arthritogenicity in SKG mice, and perhaps in patients with RA