Broader functions of TIR domains in Arabidopsis immunity.

TIR domains are NAD-degrading enzymes that function during immune signaling in prokaryotes, plants, and animals. In plants, most TIR domains are incorporated into intracellular immune receptors termed TNLs. In Arabidopsis, TIR-derived small molecules bind and activate EDS1 heterodimers, which in turn activate RNLs, a class of cation channel-forming immune receptors. RNL activation drives cytoplasmic Ca2+ influx, transcriptional reprogramming, pathogen resistance, and host cell death. We screened for mutants that suppress an RNL activation mimic allele and identified a TNL, SADR1. Despite being required for the function of an autoactivated RNL, SADR1 is not required for defense signaling triggered by other tested TNLs. SADR1 is required for defense signaling initiated by some transmembrane pattern recognition receptors and contributes to the unbridled spread of cell death in lesion simulating disease 1. Together with RNLs, SADR1 regulates defense gene expression at infection site borders, likely in a non-cell autonomous manner. RNL mutants that cannot sustain this pattern of gene expression are unable to prevent disease spread beyond localized infection sites, suggesting that this pattern corresponds to a pathogen containment mechanism. SADR1 potentiates RNL-driven immune signaling not only through the activation of EDS1 but also partially independently of EDS1. We studied EDS1-independent TIR function using nicotinamide, an NADase inhibitor. Nicotinamide decreased defense induction from transmembrane pattern recognition receptors and decreased calcium influx, pathogen growth restriction, and host cell death following intracellular immune receptor activation. We demonstrate that TIR domains can potentiate calcium influx and defense and are thus broadly required for Arabidopsis immunity.

A small proton charge radius from an electron-proton scattering experiment.

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, rp. In 2010, a new method using muonic hydrogen atoms1 found a substantial discrepancy compared with previous results2, which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e-p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e-p experiments and enabled measurements at very small forward-scattering angles. Our result, rp = 0.831 ± 0.007stat ± 0.012syst femtometres, is smaller than the most recent high-precision e-p measurement5 and 2.7 standard deviations smaller than the average of all e-p experimental results6. The smaller rp we have now measured supports the value found by two previous muonic hydrogen experiments1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant8-one of the most accurately evaluated fundamental constants in physics.

CCR2 monocytes as therapeutic targets for acute disc herniation and radiculopathy in mouse models.

OBJECTIVE: Back pain and radiculopathy caused by disc herniation are major health issues worldwide. While macrophages are key players in disc herniation induced inflammation, their roles and origins in disease progression remain unclear. We aim to study the roles of monocytes and derivatives in a mouse model of disc herniation. METHODS: Using a CCR2-CreER; R26R-EGFP (Ai6) transgenic mouse strain, we fate-mapped C-C chemokine receptor type 2 (CCR2) expressing monocytes and derivatives at disc herniation sites, and employed a CCR2RFP/RFP mouse strain and a CCR2-specific antagonist to study the effects of CCR2+ monocytes on local inflammatory responses, pain level, and disc degeneration by immunostaining, flow cytometry, and histology. RESULTS: CCR2+ monocytes (GFP+) increased at the sites of disc hernia over postoperative day 4, 6, and 9 in CCR2-CreER; Ai6 mice. F4/80+ cells increased, and meanwhile, CD11b+ cells trended downward. Co-localization analysis revealed that both GFP+CD11b+ and GFP+F4/80+ constituted the majority of CD11b+ and F4/80+ cells at disc hernia sites. Fluorescence activated cell sorter purified GFP+ cells exhibited higher cytokine expressions than GFP- cells. Inhibition of CCR2 signaling reduced infiltration of monocytes and macrophages, alleviated pain, maintained disc height, and reduced osteoclast activity in adjacent cortical bone for up to 1 month. CONCLUSION: Our findings suggest that circulating CCR2+ monocytes play important roles in initiating and promoting the local inflammatory responses, pain sensitization, and degenerative changes after disc herniation, and thus may serve as therapeutic targets for disc herniation induced back and leg pain.

Clinical Learning, Didactic Education, and Research Experiences of Radiation Oncology Resident Physicians in Canada.

Changes in the field of radiation oncology (RO) impacts residency training. Assessing trainee experiences is essential to inform curriculum development. We aim to explore gaps and strengths in current Canadian RO training, as we move towards competency-based medical education (CBME). An online survey was distributed to residents at all Canadian RO training programs. Surveys consisted of 66 open-ended, Likert-scale, matrix-style, and multiple-choice questions, and assessed clinical exposure, didactic teaching, professional relationships, and research experiences. Statistics were calculated from anonymized, aggregate responses. Out of 128 eligible residents, 53 responded (41% response rate). Of these, 57% were male, and 77% were Canadian medical graduates. Senior residents (PGY-4 to PGY-5) perceived insufficient exposure to lymphoma and ocular malignancies, brachytherapy for breast and esophagus malignancies, and stereotactic radiotherapy of the pancreas, prostate, and adrenal gland. Half (51%) had training on image-guided radiotherapy (IGRT) challenges, and 43% had a formal staff mentor. Most residents presented at least one research project at conferences (77%) and authored ≥ 1 publications (66%) during residency. Canadian RO residents are satisfied with their clinical training and educational experience in high-volume tumor sites and high-volume brachytherapy procedures. Areas identified for potential improvement are (1) low-volume tumor sites; (2) low-volume brachytherapy procedures; (3) low-volume stereotactic radiotherapy sites; (4) IGRT challenges; and (5) mentorship opportunities. These findings will inform future CBME curriculum revisions.

The association between threatened preterm labour and perinatal outcomes at term: a population-based cohort study.

OBJECTIVE: To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term. DESIGN: A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term. SETTING: Nova Scotia, Canada. POPULATION: All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019. METHODS: Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not. MAIN OUTCOME MEASURES: Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity. RESULTS: Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54). CONCLUSIONS: Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.

Motivations, Well-Being, and Career Aspirations of Radiation Oncology Resident Physicians in Canada.

Prior Pan-Canadian surveys of Radiation Oncology (RO) residents reveal a decrease in Canadian RO employment opportunities. Canadian RO resident levels increased from 130 in 2003, peaked at 209 in 2009, then decreased to 130 in 2017. Recognizing that RO has entered another period of transition, we re-examined resident motivations and perspectives on the job market and explored well-being and career aspirations among a contemporary cohort of Canadian RO residents. An online survey was distributed to residents at all Canadian RO training programs. Surveys consisted of 75 open-ended, Likert-scale, matrix-style, and multiple-choice questions. Student's t test compared subgroups, with statistical significance at p ≤ 0.05. Out of 128 eligible residents, 84 completed the survey (66% response rate) with representative sampling from each training year. Demographics reveal 53% male, and 85% Canadian registry-funded. Top training-related stressors were exam performance, job prospects, and physical/psychological demands of residency. Most intend to pursue fellowship post-residency (80%) and practice in Canada (88%). Few believe they can obtain staff positions treating preferred tumor sites (38%) or at preferred geographic locations (28%). Residents view job market being less competitive than 5 years ago (40%) and predict it will be less competitive in 5 years (60%). Canadian RO residents feel adequately trained, and most pursue post-residency fellowships. Current perceptions of the Canadian job market remain guarded, but appear more optimistic about the future. This update provides insights into current RO training and identifies areas that could be addressed by incoming competency-based medical education models for RO.

2b or not 2b? Shoulder function after level 2b neck dissection: A double-blind randomized controlled clinical trial.

BACKGROUND: Selective neck dissection (SND) is a mainstay of head and neck cancer treatment. A common sequela is shoulder syndrome from spinal accessory nerve (SAN) trauma. Extensive dissection in neck levels 2 and 5 leads to SAN dysfunction. However, it is not known whether limited level 2 dissection reduces SAN injury. The purpose of this double-blind randomized controlled trial was to determine whether omitting level 2b dissection would improve shoulder-related quality of life and function. METHODS: Patients with head and neck cancers undergoing surgery were randomized 1:1 to SND without level 2b dissection (group 1) or with it (group 2) on their dominant-hand side. Patients, caregivers, and assessors were blinded. The primary outcome was the change in the Neck Dissection Impairment Index (NDII) score after 6 months. An a priori calculation of the minimally important clinical difference in the NDII score was determined to establish a sample size of 15 patients per group (power = 0.8). Secondary outcomes included shoulder strength and range of motion (ROM) and SAN nerve conduction. The trial was registered at ClinicalTrials.gov (NCT00765791). RESULTS: Forty patients were enrolled, and 30 were included (15 per group). Six months after the surgery, group 2 demonstrated a significant median decrease in the NDII from the baseline (30 points) and in comparison with group 1, whose NDII dropped 17.5 points (P = .02). Shoulder ROM and SAN conduction demonstrated significant declines in group 2 (P ≤ .05). No adverse events occurred. CONCLUSIONS: Level 2b should be omitted in SND when this is oncologically safe and feasible. This allows for an optimal balance between function and cancer cure.

First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Quick X-ray reflectivity using monochromatic synchrotron radiation for time-resolved applications.

A new technique for the parallel collection of X-ray reflectivity (XRR) data, compatible with monochromatic synchrotron radiation and flat substrates, is described and applied to the in situ observation of thin-film growth. The method employs a polycapillary X-ray optic to produce a converging fan of radiation, incident onto a sample surface, and an area detector to simultaneously collect the XRR signal over an angular range matching that of the incident fan. Factors determining the range and instrumental resolution of the technique in reciprocal space, in addition to the signal-to-background ratio, are described in detail. This particular implementation records ∼5° in 2θ and resolves Kiessig fringes from samples with layer thicknesses ranging from 3 to 76 nm. The value of this approach is illustrated by showing in situ XRR data obtained with 100 ms time resolution during the growth of epitaxial La0.7Sr0.3MnO3 on SrTiO3 by pulsed laser deposition at the Cornell High Energy Synchrotron Source (CHESS). Compared with prior methods for parallel XRR data collection, this is the first method that is both sample-independent and compatible with the highly collimated, monochromatic radiation typical of third-generation synchrotron sources. Further, this technique can be readily adapted for use with laboratory-based sources.

Measurement of the Q

We measured the g_{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9 GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02 GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

Ulnar collateral ligament reconstruction in athletes using a cortical button suspension technique.

BACKGROUND: A variety of techniques currently exist for ulnar collateral ligament (UCL) reconstruction in symptomatic overhead athletes, all with the potential complication of fracture about the humeral or ulnar tunnels. Far cortical button fixation is a reproducible, biomechanically attractive option; however, no clinical series has been published on this technique to date. This study reports the clinical outcomes, with minimum 2-year follow-up, of a dual far cortical button suspension technique for UCL reconstruction in athletes. METHODS: A retrospective evaluation was performed of 23 consecutive athletes who underwent UCL reconstruction with the use of ulnar and humeral-sided far cortical button fixation with minimum 2 years of follow-up. Data were collected from electronic medical records and patient telephone calls. The primary outcome was return to sport. Secondary outcomes included Disabilities of the Arm, Shoulder and Hand score, range of motion, and complications. RESULTS: We included 23 athletes with a mean follow-up of 47.2 months (range, 24-81 months). Autograft was used in 22 patients (16 palmaris, 6 gracilis, 1 semitendinosus, and 1 gracilis allograft). Overall, 82.6% (19 of 23) of patients returned to sport. At final follow-up, the average Disabilities of the Arm, Shoulder and Hand score was 3.8, and range of motion averaged 0° to 140°, with 87% (20 of 23) of patients achieving full motion. The visual analog scale score improved from 3.8 preoperatively to 0.2 at the final follow-up (P < .0001). There was 1 reconstruction failure. CONCLUSIONS: The humeral and ulnar far cortical button suspension technique provides a new UCL fixation option with theoretically lower concern for tunnel fracture and with predictable return to sport and good functional outcomes.

Radiologic and clinical evaluation of a bioabsorbable collagen implant to treat partial-thickness tears: a prospective multicenter study.

BACKGROUND: Treatment of partial-thickness cuff tears remains controversial. Although conservative therapy may treat symptoms, these defects do not spontaneously heal and conversion to a full-thickness lesion with subsequent repair may alter the tendon footprint. The ability to induce new tissue formation and limit tear progression in intermediate- and high-grade partial-thickness tears without surgical repair may represent a significant advancement in the treatment paradigm for these lesions. METHODS: We prospectively enrolled 33 patients with chronic, degenerative, intermediate-grade (n = 12) or high-grade (n = 21) partial-thickness tears (11 articular, 10 bursal, 4 intrasubstance, and 8 hybrid) of the supraspinatus tendon in a multicenter study. Following arthroscopic subacromial decompression without repair, a bioinductive implant was attached over the bursal surface of the tendon. Clinical outcomes were assessed using American Shoulder and Elbow Surgeons and Constant-Murley scores preoperatively and at 3 and 12 months postoperatively. Magnetic resonance imaging was performed to assess postoperative tendon healing and thickness at the original tear site. RESULTS: At 1-year follow-up, clinical scores improved significantly (P <.0001) and the mean tendon thickness increased by 2.0 mm (P <.0001). Magnetic resonance imaging evidence of complete healing was found in 8 patients and a considerable reduction in defect size was shown in 23, whereas 1 lesion remained stable. In 1 noncompliant patient with a high-grade articular lesion, progression to a full-thickness tear occurred while shoveling snow 1 month after surgery. No serious adverse events related to the implant were reported. CONCLUSIONS: Arthroscopic implantation of a bioinductive collagen scaffold is a safe and effective treatment for intermediate- to high-grade partial-thickness rotator cuff tears of the supraspinatus tendon.

Decadal-scale response of detritivorous surgeonfishes (family Acanthuridae) to no-take marine reserve protection and changes in benthic habitat.

No-take marine reserves (NTMR) are increasingly being implemented to mitigate the effects of fishing on coral reefs, yet determining the efficacy of NTMRs depends largely on partitioning the effects of fishing from the effect of benthic habitat. Species of coral-reef fishes typically decline in density when subjected to fishing or benthic disturbances, but this is not always the case. This study documents the long-term (8-31 years) response of six species of detritivorous surgeonfishes (family Acanthuridae) to NTMR protection and benthic habitat change at four islands (Apo, Sumilon, Mantigue, Selinog) in the central Philippines, each island with a NTMR and a monitored fished site. Despite being subject to moderate fishing pressure, these species did not increase in density with NTMR protection. However, density of these surgeonfishes had a strong negative relationship with cover of live hard coral and a strong positive relationship with cover of dead substratum (sand, rubble, hard dead substratum). These surgeonfishes typically feed over dead substrata and thus probably increase in density following large environmental disturbances that substantially reduce live hard coral cover. Here, we describe effects of environmental disturbance events (e.g., use of explosives, typhoons) that reduced live hard-coral cover and subsequent large increases (up to 25 fold) in surgeonfish densities, which then slowly (over 5-15 years) decreased in density as live hard coral recovered. Density of these functionally important surgeonfish species was influenced more by changes to benthic cover than by NTMR protection. Thus, we highlight the greater importance of bottom-up controls (i.e., benthic changes to food availability) than top-down control (i.e., fishing) on a functionally important group of coral-reef fishes.

A cadaver study comparing three fibreoptic-assisted techniques for converting a supraglottic airway to a cuffed tracheal tube.

After rescuing an airway with a supraglottic airway device, a method to convert it to a cuffed tracheal tube is often needed. The best method to do this has never been directly studied. We compared three techniques for conversion of a standard LMA® Unique airway to a cuffed endotracheal tube using a fibrescope. The primary endpoint was time to intubation, with secondary endpoints of success rate, perceived difficulty and preferred technique. We also investigated the relationship between level of training and prior training and experience with the techniques on the primary outcome. The mean (95% CI) time to intubation using a direct tracheal tube technique of 37 (31-42) s was significantly shorter than either the Aintree intubation catheter technique at 70 (60-80) s, or a guidewire technique at 126 (110-141) s (p < 0.001). Most (13/24) participants rated the tracheal tube as their preferred technique, while 11/24 preferred the Aintree technique. In terms of perceived difficulty, 23/24, 21/24 and 9/24 participants rated the tracheal tube technique, Aintree technique and guidewire technique, respectively, as either very easy or easy. There was no relationship between prior training, prior experience or level of training on time to completion of any of the techniques. We conclude the tracheal tube and Aintree techniques both provide a rapid and easy method for conversion of a supraglottic airway device to a cuffed tracheal tube. The guidewire technique cannot be recommended.

The evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer: recommendations by an International TILs Working Group 2014.

BACKGROUND: The morphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer (BC) is gaining momentum as evidence strengthens for the clinical relevance of this immunological biomarker. Accumulating evidence suggests that the extent of lymphocytic infiltration in tumor tissue can be assessed as a major parameter by evaluation of hematoxylin and eosin (H&E)-stained tumor sections. TILs have been shown to provide prognostic and potentially predictive value, particularly in triple-negative and human epidermal growth factor receptor 2-overexpressing BC. DESIGN: A standardized methodology for evaluating TILs is now needed as a prerequisite for integrating this parameter in standard histopathological practice, in a research setting as well as in clinical trials. This article reviews current data on the clinical validity and utility of TILs in BC in an effort to foster better knowledge and insight in this rapidly evolving field, and to develop a standardized methodology for visual assessment on H&E sections, acknowledging the future potential of molecular/multiplexed approaches. CONCLUSIONS: The methodology provided is sufficiently detailed to offer a uniformly applied, pragmatic starting point and improve consistency and reproducibility in the measurement of TILs for future studies.

Longitudinal target-spin asymmetries for deeply virtual compton scattering.

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.

Impact of conservation areas on trophic interactions between apex predators and herbivores on coral reefs.

Apex predators are declining at alarming rates due to exploitation by humans, but we have yet to fully discern the impacts of apex predator loss on ecosystem function. In a management context, it is critically important to clarify the role apex predators play in structuring populations of lower trophic levels. Thus, we examined the top-down influence of reef sharks (an apex predator on coral reefs) and mesopredators on large-bodied herbivores. We measured the abundance, size structure, and biomass of apex predators, mesopredators, and herbivores across fished, no-take, and no-entry management zones in the Great Barrier Reef Marine Park, Australia. Shark abundance and mesopredator size and biomass were higher in no-entry zones than in fished and no-take zones, which indicates the viability of strictly enforced human exclusion areas as tools for the conservation of predator communities. Changes in predator populations due to protection in no-entry zones did not have a discernible influence on the density, size, or biomass of different functional groups of herbivorous fishes. The lack of a relationship between predators and herbivores suggests that top-down forces may not play a strong role in regulating large-bodied herbivorous coral reef fish populations. Given this inconsistency with traditional ecological theories of trophic cascades, trophic structures on coral reefs may need to be reassessed to enable the establishment of appropriate and effective management regimes.

Present status and future directions of intraoperative radiotherapy.

In this Review, we summarise recent published work on the use of intraoperative radiotherapy to treat common tumour sites in the primary or recurrent setting. Techniques, radiobiology, and the physics of intraoperative radiotherapy are also explored. Disease sites discussed in this Review include head and neck cancer, breast cancer, sarcoma, gastrointestinal cancer, genitourinary cancer, gynaecological cancer, thoracic cancer, and palliative applications.

An improved method for generating human spinal cord neural stem cells.

Neural stem cells have exhibited efficacy in pre-clinical models of spinal cord injury (SCI) and are on a translational path to human testing. We recently reported that neural stem cells must be driven to a spinal cord fate to optimize host axonal regeneration into sites of implantation in the injured spinal cord, where they subsequently form neural relays across the lesion that support significant functional improvement. We also reported methods of deriving and culturing human spinal cord neural stem cells derived from embryonic stem cells that can be sustained over serial high passage numbers in vitro, providing a potentially optimized cell source for human clinical trials. We now report further optimization of methods for deriving and sustaining cultures of human spinal cord neural stem cell lines that result in improved karyotypic stability while retaining anatomical efficacy in vivo. This development improves prospects for safe human translation.