mTORC2 Responds to Glutamine Catabolite Levels to Modulate the Hexosamine Biosynthesis Enzyme GFAT1.

Highly proliferating cells are particularly dependent on glucose and glutamine for bioenergetics and macromolecule biosynthesis. The signals that respond to nutrient fluctuations to maintain metabolic homeostasis remain poorly understood. Here, we found that mTORC2 is activated by nutrient deprivation due to decreasing glutamine catabolites. We elucidate how mTORC2 modulates a glutamine-requiring biosynthetic pathway, the hexosamine biosynthesis pathway (HBP) via regulation of expression of glutamine:fructose-6-phosphate amidotransferase 1 (GFAT1), the rate-limiting enzyme of the HBP. GFAT1 expression is dependent on sufficient amounts of glutaminolysis catabolites particularly α-ketoglutarate, which are generated in an mTORC2-dependent manner. Additionally, mTORC2 is essential for proper expression and nuclear accumulation of the GFAT1 transcriptional regulator, Xbp1s. Thus, while mTORC1 senses amino acid abundance to promote anabolism, mTORC2 responds to declining glutamine catabolites in order to restore metabolic homeostasis. Our findings uncover the role of mTORC2 in metabolic reprogramming and have implications for understanding insulin resistance and tumorigenesis.

Intravenous Cefazolin Achieves Sustained High Interstitial Concentrations in Open Lower Extremity Fractures.

BACKGROUND: Infection remains a serious clinical concern in patients with open fractures, despite timely antibiotic administration and surgical debridement. Soft tissue and periosteal stripping may alter local tissue homeostasis and antibiotic pharmacokinetics in the injured limb. The tissue (interstitial) concentration of intravenously administered antibiotics at an open fracture site has not been characterized using direct sampling techniques. QUESTION/PURPOSE: We performed this study to evaluate the concentration and pharmacokinetics of intravenously delivered cefazolin at an open fracture site after surgical debridement. METHODS: Twelve patients with an open fracture distal to the knee who presented at a regional Level I trauma center were approached for enrollment in this nonrandomized, observational study. Of the 12 patients, eight adults (one female, seven male) with a median age of 32 years (range 23 to 51 years) were enrolled and underwent successful sample collection for analysis. Three patients had incomplete datasets because of equipment malfunction and one elected not to participate. Seven patients had open tibia fractures, and one patient had an open fibula fracture associated with a closed tibia fracture. There were six Gustilo-Anderson Type II injuries and two Type IIIA injuries. Empiric antibiotics were administered in the prehospital setting or in the emergency department according to institutional protocol. When patients were taken to the operating room, a 2-g intravenous dose of cefazolin was administered. After surgical debridement, fracture stabilization, and wound closure, a microdialysis catheter was placed transdermally into the injury zone (within 5 cm of the fracture site) and a second catheter was placed in the contralateral uninjured (control) limb. Additional doses of cefazolin were administered every 8 hours postoperatively. Baseline and periodic interstitial fluid and whole blood (plasma) samples were collected in the operating room and at prespecified times for 24 hours postoperatively. Free cefazolin in the interstitial fluid and plasma samples were analyzed by ultra-high-performance liquid chromatography using C 18 column separation with quadrupole time-of-flight mass spectrometry detection. Data from the second postoperative dose of cefazolin were used to characterize pharmacokinetic parameters through a noncompartmental analysis using time-concentration curves of free cefazolin and assuming first-order elimination. For pharmacodynamic analyses, the modal cefazolin minimum inhibitory concentration (MIC) of Staphylococcus aureus (1 µg/mL) was used. RESULTS: With the samples available, no difference was observed in the median free cefazolin exposure over 24 hours ( f area under the curve [AUC] 0→24hrs ) between injured limbs (352 µg∙hr/mL [IQR 284 to 594 µg∙hr/mL]) and uninjured limbs (341 µg∙hr/mL [IQR 263 to 438 µg∙hr/mL]; p = 0.64). The median time to achieve the maximum concentration of free cefazolin ( f T max ) for injured limbs was delayed (2.7 hours [IQR 2.2 to 3.1 hours]) compared with control limbs (1.7 hours [IQR 1.2 to 2.0 hours]; p = 0.046). The time to the maximum concentration for plasma was not different from that of control limbs (p = 0.08). The time the cefazolin concentration was above the modal S. aureus MIC (T > MIC) in the injured and control limbs over 24 hours was 100% (IQR 100% to 100%) and 100% (IQR 97% to 100%), respectively. CONCLUSION: These preliminary findings suggest that current prophylactic cefazolin dosing regimens result in successful antibiotic delivery to the traumatized limb in moderately severe open fractures. Although cefazolin delivery to open-fracture wound beds was delayed compared with healthy tissues, the cefazolin concentration was sustained above the European Union Committee Antimicrobial Susceptibility Testing modal MIC for S. aureus , demonstrating a high likelihood of a prophylactic antimicrobial environment at an open fracture site with this empiric antimicrobial regimen. Importantly, patients in this analysis had Gustilo-Anderson Types II and IIIA injuries. Further research with a larger patient cohort is needed to determine whether antibiotic delivery to traumatized soft tissues in patients with higher-grade open fractures (Gustilo-Anderson Types IIIB and IIIC) demonstrates similar pharmacokinetic characteristics. LEVEL OF EVIDENCE: Level II, therapeutic study.

Surveillance Imaging after Primary Diagnosis of Ductal Carcinoma in Situ.

Background Guidelines recommend annual surveillance imaging after diagnosis of ductal carcinoma in situ (DCIS). Guideline adherence has not been characterized in a contemporary cohort. Purpose To identify uptake and determinants of surveillance imaging in women who underwent treatment for DCIS. Materials and Methods A stratified random sample of women who underwent breast-conserving surgery for primary DCIS between 2008 and 2014 was retrospectively selected from 1330 facilities in the United States. Imaging examinations were recorded from date of diagnosis until first distant recurrence, death, loss to follow-up, or end of study (November 2018). Imaging after treatment was categorized into 10 12-month periods starting 6 months after diagnosis. Primary outcome was per-period receipt of asymptomatic surveillance imaging (mammography, MRI, or US). Secondary outcome was diagnosis of ipsilateral invasive breast cancer. Multivariable logistic regression with repeated measures and generalized estimating equations was used to model receipt of imaging. Rates of diagnosis with ipsilateral invasive breast cancer were compared between women who did and those who did not undergo imaging in the 6-18-month period after diagnosis using inverse probability-weighted Kaplan-Meier estimators. Results A total of 12 559 women (median age, 60 years; IQR, 52-69 years) were evaluated. Uptake of surveillance imaging was 75% in the first period and decreased over time (P < .001). Across the first 5 years after treatment, 52% of women participated in consistent annual surveillance. Surveillance was lower in Black (adjusted odds ratio [OR], 0.80; 95% CI: 0.74, 0.88; P < .001) and Hispanic (OR, 0.82; 95% CI: 0.72, 0.94; P = .004) women than in White women. Women who underwent surveillance in the first period had a higher 6-year rate of diagnosis of invasive cancer (1.6%; 95% CI: 1.3, 1.9) than those who did not (1.1%; 95% CI: 0.7, 1.4; difference: 0.5%; 95% CI: 0.1, 1.0; P = .03). Conclusion Half of women did not consistently adhere to imaging surveillance guidelines across the first 5 years after treatment, with racial disparities in adherence rates. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Rahbar and Dontchos in this issue.

Sox9 and Lef1 Regulate the Fate and Behavior of Airway Glandular Progenitors in Response to Injury.

Cartilaginous airways of larger mammals and the mouse trachea contain at least 3 well-established stem cell compartments, including basal cells of the surface airway epithelium (SAE) and ductal and myoepithelial cells of the submucosal glands (SMG). Here we demonstrate that glandular Sox9-expressing progenitors capable of SAE repair decline with age in mice. Notably, Sox9-lineage glandular progenitors produced basal and ciliated cells in the SAE, but failed to produce secretory cells. Lef1 was required for glandular Sox9 lineage contribution to SAE repair, and its deletion significantly reduced proliferation following injury. By contrast, in vivo deletion of Sox9 enhanced proliferation of progenitors in both the SAE and SMG shortly following injury, but these progenitors failed to proliferate in vitro in the absence of Sox9, similar to that previously shown for Lef1 deletion. In cystic fibrosis ferret airways, Sox9 expression inversely correlated with Ki67 proliferative marker expression in SMG and the SAE. Using in vitro and ex vivo models, we demonstrate that Sox9 is extinguished as glandular progenitors exit ducts and proliferate on the airway surface and that Sox9 is required for migration and proper differentiation of SMG, but not surface airway, progenitors. We propose a model whereby Wnt/Lef1 and Sox9 signals differentially regulate the proliferative and migratory behavior of glandular progenitors, respectively.

ExPeCT: a randomised trial examining the impact of exercise on quality of life in men with metastatic prostate cancer.

PURPOSE: All patients living with cancer, including those with metastatic cancer, are encouraged to be physically active. This paper examines the secondary endpoints of an aerobic exercise intervention for men with metastatic prostate cancer. METHODS: ExPeCT (Exercise, Prostate Cancer and Circulating Tumour Cells), was a multi-centre randomised control trial with a 6-month aerobic exercise intervention arm or a standard care control arm. Exercise adherence data was collected via heart rate monitors. Quality of life (FACT-P) and physical activity (self-administered questionnaire) assessments were completed at baseline, at 3 months and at 6 months. RESULTS: A total of 61 patients were included (69.4 ± 7.3 yr, body mass index 29.2 ± 5.8 kg/m2). The median time since diagnosis was 34 months (IQR 7-54). A total of 35 (55%) of participants had > 1 region affected by metastatic disease. No adverse events were reported by participants. There was no effect of exercise on quality of life (Cohen's d = - 0.082). Overall adherence to the supervised sessions was 83% (329 out of 396 possible sessions attended by participants). Overall adherence to the non-supervised home exercise sessions was 72% (months 1-3) and 67% (months 3-6). Modelling results for overall physical activity scores showed no significant main effect for the group (p-value = 0.25) or for time (p-value = 0.24). CONCLUSION: In a group of patients with a high burden of metastatic prostate cancer, a 6-month aerobic exercise intervention did not lead to change in quality of life. Further exercise studies examining the role of exercise for people living with metastatic prostate cancer are needed. TRIAL REGISTRATION: The trial was registered at clinicaltrials.gov (NCT02453139) on May 25th 2015.

Alternate Graft Options for Staged Flexor Tendon Reconstruction: A Cadaveric Study of Hamstring Autografts Compared to Conventional Autografts.

PURPOSE: To compare the semitendinosus and gracilis tendon lengths and diameters to the palmaris longus, plantaris, flexor digitorum profundus, and flexor pollicis longus (FPL) tendons in a cadaveric model to evaluate the feasibility of hamstring autograft use for staged flexor tendon reconstruction. METHODS: Fifteen fresh cadavers were evaluated for surgical incisions about the knee, forearm, and hand. All flexor digitorum profundus (FDP), FPL, palmaris longus, plantaris, semitendinosus, and gracilis tendons were harvested from each specimen. Diameter and length were recorded and means with SDs were calculated. The mean diameters of the gracilis and semitendinosus were compared to the mean diameters of the FDP and FPL tendons. The hamstring tendon lengths were then compared in terms of percentage of the palmaris longus and plantaris tendon lengths. RESULTS: The gracilis (18.0 cm) and semitendinosus (19.9 cm) means were notably longer than the palmaris longus (16.0 cm) and shorter than the plantaris (30.0 cm). The average gracilis tendon diameter (3.8 mm) was smaller than the flexor tendon diameters except for the little finger FDP (3.8 mm). The semitendinosus tendon diameter (4.8 mm) was larger than all flexor tendons with the exception of the middle finger FDP (4.6 mm). Average gracilis and semitendinosus tendon diameters were 3.7 mm and 4.5 mm in males, and 3.8 mm and 4.8 mm in females. CONCLUSIONS: This study showed the gracilis tendon to have adequate length and diameter for potential autograft use in staged flexor tendon reconstruction in all digits but the little finger. The semitendinosus is larger in diameter than the native flexor tendons, making it a poor autograft option in cases with an intact pulley system. CLINICAL RELEVANCE: Common tendon autograft options for flexor tendon reconstruction are variably present, and the use of gracilis and semitendinosus autograft present potential graft options.

Stem cells, cell therapies, and bioengineering in lung biology and disease 2021.

The 9th biennial conference titled "Stem Cells, Cell Therapies, and Bioengineering in Lung Biology and Diseases" was hosted virtually, due to the ongoing COVID-19 pandemic, in collaboration with the University of Vermont Larner College of Medicine, the National Heart, Lung, and Blood Institute, the Alpha-1 Foundation, the Cystic Fibrosis Foundation, and the International Society for Cell & Gene Therapy. The event was held from July 12th through 15th, 2021 with a pre-conference workshop held on July 9th. As in previous years, the objectives remained to review and discuss the status of active research areas involving stem cells (SCs), cellular therapeutics, and bioengineering as they relate to the human lung. Topics included 1) technological advancements in the in situ analysis of lung tissues, 2) new insights into stem cell signaling and plasticity in lung remodeling and regeneration, 3) the impact of extracellular matrix in stem cell regulation and airway engineering in lung regeneration, 4) differentiating and delivering stem cell therapeutics to the lung, 5) regeneration in response to viral infection, and 6) ethical development of cell-based treatments for lung diseases. This selection of topics represents some of the most dynamic and current research areas in lung biology. The virtual workshop included active discussion on state-of-the-art methods relating to the core features of the 2021 conference, including in situ proteomics, lung-on-chip, induced pluripotent stem cell (iPSC)-airway differentiation, and light sheet microscopy. The conference concluded with an open discussion to suggest funding priorities and recommendations for future research directions in basic and translational lung biology.

"Is it cancer or not?" A qualitative exploration of survivor concerns surrounding the diagnosis and treatment of ductal carcinoma in situ.

BACKGROUND: Of the nearly 50,000 women in the United States who undergo treatment for ductal carcinoma in situ (DCIS) annually, many may not benefit from treatment. To better understand the impact of a DCIS diagnosis, patients self-identified as having had DCIS were engaged regarding their experience. METHODS: In July 2014, a web-based survey was administered through the Susan Love Army of Women breast cancer listserv. The survey included open-ended questions designed to assess patients' perspectives about DCIS diagnosis and treatment. Deductive and inductive codes were applied to the responses; common themes were summarized. RESULTS: Among the 1832 women included in the analytic sample, the median age at diagnosis was 60 years. Four primary themes were identified: 1) uncertainty surrounding a DCIS diagnosis, 2) uncertainty about DCIS treatment, 3) concern about treatment side effects, and 4) concern about recurrence and/or developing invasive breast cancer. When diagnosed, participants were often uncertain about whether they had cancer or not and whether they should be considered a "survivor." Uncertainty about treatment manifested as questioning the appropriateness of the amount of treatment received. Participants expressed concern about the "cancer spreading" or becoming invasive and that they were not necessarily "doing enough" to prevent recurrence. CONCLUSIONS: In a large, national sample, participants with a history of DCIS reported confusion and concern about the diagnosis and treatment, which caused worry and significant uncertainty. Developing strategies to improve patient and provider communications regarding the nature of DCIS and acknowledging gaps in the current knowledge of management options should be a priority.

Prediction of Upstaging in Ductal Carcinoma in Situ Based on Mammographic Radiomic Features.

Background Improving diagnosis of ductal carcinoma in situ (DCIS) before surgery is important in choosing optimal patient management strategies. However, patients may harbor occult invasive disease not detected until definitive surgery. Purpose To assess the performance and clinical utility of mammographic radiomic features in the prediction of occult invasive cancer among women diagnosed with DCIS on the basis of core biopsy findings. Materials and Methods In this Health Insurance Portability and Accountability Act-compliant retrospective study, digital magnification mammographic images were collected from women who underwent breast core-needle biopsy for calcifications that was performed at a single institution between September 2008 and April 2017 and yielded a diagnosis of DCIS. The database query was directed at asymptomatic women with calcifications without a mass, architectural distortion, asymmetric density, or palpable disease. Logistic regression with regularization was used. Differences across training and internal test set by upstaging rate, age, lesion size, and estrogen and progesterone receptor status were assessed by using the Kruskal-Wallis or χ2 test. Results The study consisted of 700 women with DCIS (age range, 40-89 years; mean age, 59 years ± 10 [standard deviation]), including 114 with lesions (16.3%) upstaged to invasive cancer at subsequent surgery. The sample was split randomly into 400 women for the training set and 300 for the testing set (mean ages: training set, 59 years ± 10; test set, 59 years ± 10; P = .85). A total of 109 radiomic and four clinical features were extracted. The best model on the test set by using all radiomic and clinical features helped predict upstaging with an area under the receiver operating characteristic curve of 0.71 (95% CI: 0.62, 0.79). For a fixed high sensitivity (90%), the model yielded a specificity of 22%, a negative predictive value of 92%, and an odds ratio of 2.4 (95% CI: 1.8, 3.2). High specificity (90%) corresponded to a sensitivity of 37%, positive predictive value of 41%, and odds ratio of 5.0 (95% CI: 2.8, 9.0). Conclusion Machine learning models that use radiomic features applied to mammographic calcifications may help predict upstaging of ductal carcinoma in situ, which can refine clinical decision making and treatment planning. © RSNA, 2022.

Lef-1 controls cell cycle progression in airway basal cells to regulate proliferation and differentiation.

The mammalian airways are lined by a continuous epithelial layer that is maintained by diverse populations of resident multipotent stem cells. These stem cells are responsible for replenishing the epithelium both at homeostasis and following injury, making them promising targets for stem cell and genetic-based therapies for a variety of respiratory diseases. However, the mechanisms that regulate when and how these stem cells proliferate, migrate, and differentiate remains incompletely understood. Here, we find that the high mobility group (HMG) domain transcription factor Lef-1 regulates proliferation and differentiation of mouse tracheal basal cells. We demonstrate that conditional deletion of Lef-1 stalls basal cell proliferation at the G1/S transition of the cell cycle, and that Lef-1 knockout cells are unable to maintain luminal tracheal cell types in long-term air-liquid interface culture. RNA sequencing analysis revealed that Lef-1 knockout (Lef-1KO) results in downregulation of key DNA damage response and cell cycle progression genes, including the kinase Chek1. Furthermore, chemical inhibition of Chek1 is sufficient to stall basal cell self-renewal in a similar fashion as Lef-1 deletion. Notably, the cell cycle block imposed by Lef-1KO in vitro is transient and basal cells eventually compensate to proliferate normally in a Chek1-independent manner. Finally, Lef-1KO cells were unable to fully regenerate tracheal epithelium following injury in vivo. These findings reveal that Lef-1 is essential for proper basal cell function. Thus, modulating Lef-1 function in airway basal cells may have applications in regenerative medicine.

A multi-modal exploration of heterogeneous physico-chemical properties of DCIS breast microcalcifications.

Ductal carcinoma in situ (DCIS) is frequently associated with breast calcification. This study combines multiple analytical techniques to investigate the heterogeneity of these calcifications at the micrometre scale. X-ray diffraction, scanning electron microscopy and Raman and Fourier-transform infrared spectroscopy were used to determine the physicochemical and crystallographic properties of type II breast calcifications located in formalin fixed paraffin embedded DCIS breast tissue samples. Multiple calcium phosphate phases were identified across the calcifications, distributed in different patterns. Hydroxyapatite was the dominant mineral, with magnesium whitlockite found at the calcification edge. Amorphous calcium phosphate and octacalcium phosphate were also identified close to the calcification edge at the apparent mineral/matrix barrier. Crystallographic features of hydroxyapatite also varied across the calcifications, with higher crystallinity centrally, and highest carbonate substitution at the calcification edge. Protein was also differentially distributed across the calcification and the surrounding soft tissue, with collagen and ß-pleated protein features present to differing extents. Combination of analytical techniques in this study was essential to understand the heterogeneity of breast calcifications and how this may link crystallographic and physicochemical properties of calcifications to the surrounding tissue microenvironment.

O-GlcNAcylation regulates cancer metabolism and survival stress signaling via regulation of the HIF-1 pathway.

The hexosamine biosynthetic pathway elevates posttranslational addition of O-linked ß-N-acetylglucosamine (O-GlcNAc) on intracellular proteins. Cancer cells elevate total O-GlcNAcylation by increasing O-GlcNAc transferase (OGT) and/or decreasing O-GlcNAcase (OGA) levels. Reducing O-GlcNAcylation inhibits oncogenesis. Here, we demonstrate that O-GlcNAcylation regulates glycolysis in cancer cells via hypoxia-inducible factor 1 (HIF-1α) and its transcriptional target GLUT1. Reducing O-GlcNAcylation increases α-ketoglutarate, HIF-1 hydroxylation, and interaction with von Hippel-Lindau protein (pVHL), resulting in HIF-1α degradation. Reducing O-GlcNAcylation in cancer cells results in activation of endoplasmic reticulum (ER) stress and cancer cell apoptosis mediated through C/EBP homologous protein (CHOP). HIF-1α and GLUT1 are critical for OGT-mediated regulation of metabolic stress, as overexpression of stable HIF-1 or GLUT1 rescues metabolic defects. Human breast cancers with high levels of HIF-1α contain elevated OGT, and lower OGA levels correlate independently with poor patient outcome. Thus, O-GlcNAcylation regulates cancer cell metabolic reprograming and survival stress signaling via regulation of HIF-1α.

The benefits and challenges of established peer support programmes for patients, informal caregivers, and healthcare providers.

PURPOSE: Peer support programmes that provide services for various health conditions have been in existence for many years; however, there is little study of their benefits and challenges. Our goal was to explore how existing peer support programmes help patients with a variety of health conditions, the challenges that these programmes meet, and how they are addressed. METHODS: We partnered with 7 peer support programmes operating in healthcare and community settings and conducted 43 semi-structured interviews with key informants. Audiorecordings were transcribed and qualitative analysis was conducted using grounded theory methods. RESULTS: Peer support programmes offer informational and psychosocial support, reduce social isolation, and connect patients and caregivers to others with similar health issues. These programmes provide a supportive community of persons who have personal experience with the same health condition and who can provide practical information about self-care and guidance in navigating the health system. Peer support is viewed as different from and complementary to professional healthcare services. Existing programmes experience challenges such as matching of peer supporter and peer recipient and maintaining relationship boundaries. They have gained experience in addressing some of these challenges. CONCLUSIONS: Peer support programmes can help persons and caregivers manage health conditions but also face challenges that need to be addressed through organizational processes. Peer support programmes have relevance for improving healthcare systems, especially given the increased focus on becoming more patient-centred. Further study of peer programmes and their relevance to improving individuals' well-being is warranted.

Feasibility of ultrashort echo time (UTE) T2* cartilage mapping in the hip: a pilot study.

BACKGROUND: Ultrashort echo time (UTE) T2* is sensitive to molecular changes within the deep calcified layer of cartilage. Feasibility of its use in the hip needs to be established to determine suitability for clinical use. PURPOSE: To establish feasibility of UTE T2* cartilage mapping in the hip and determine if differences in regional values exist. MATERIAL AND METHODS: MRI scans with UTE T2* cartilage maps were prospectively acquired on eight hips. Hip cartilage was segmented into whole and deep layers in anterosuperior, superior, and posterosuperior regions. Quantitative UTE T2* maps were analyzed (independent one-way ANOVA) and reliability was calculated (ICC). RESULTS: UTE T2* mean values (anterosuperior, superior, posterosuperior): full femoral layer (19.55, 18.43, 16.84 ms) (P=0.004), full acetabular layer (19.37, 17.50, 16.73 ms) (P=0.013), deep femoral layer (18.68, 17.90, 15.74 ms) (P=0.010), and deep acetabular layer (17.81, 16.18, 15.31 ms) (P=0.007). Values were higher in anterosuperior compared to posterosuperior regions (mean difference; 95% confidence interval [CI]): full femur layer (2.71 ms; 95% CI 0.91-4.51: P=0.003), deep femur layer (2.94 ms; 95% CI 0.69-5.19; P=0.009), full acetabular layer (2.63 ms 95% CI 0.55-4.72; P=0.012), and deep acetabular layer (2.50 ms; 95% CI 0.69-4.30; P=0.006). Intra-reader (ICC 0.89-0.99) and inter-reader reliability (ICC 0.63-0.96) were good to excellent for the majority of cartilage layers. CONCLUSION: UTE T2* cartilage mapping was feasible in the hip with mean values in the range of 16.84-19.55 ms in the femur and 16.73-19.37 ms in the acetabulum. Significantly higher values were present in the anterosuperior region compared to the posterosuperior region.

Magnetic resonance imaging does not reliably detect Kaplan fiber injury in the setting of anterior cruciate ligament tear.

PURPOSE: There has been a continued effort to better understand the role Kaplan fiber injury plays in persistent instability following ACL tears. However, the prevalence of these injuries remains poorly understood. Therefore, the purpose of this study was to define the prevalence of Kaplan fiber injury in the setting of complete anterior cruciate ligament tear using a commonly used grading system for assessing ligament injuries. The inter-rater reliability of this commonly used grading system and the relationship between Kaplan fiber injury and injury to other structures commonly found in conjunction with ACL tears was also evaluated. METHODS: All isolated, complete anterior cruciate ligament tears confirmed on magnetic resonance imaging within 90 days of injury between 2014 and 2020 at a single institution were included for analysis. Each scan was read by two, fellowship-trained musculoskeletal radiologists. Kaplan fiber injury was evaluated using a previously described grading scheme. Kappa, [Formula: see text], of inter-rater agreement was determined for all magnetic resonance image scans. Kruskal Wallis test was performed to assess for associations between Kaplan fiber injury and magnet strength (1.5 T vs. 3.0 T), patient gender, the presence of medial and/or lateral meniscal tears, and/or posterolateral tibial bone bruise. RESULTS: Between 2014 and 2020, 131 patients (94 males, 37 females) with a complete anterior cruciate ligament tear were included in the final analysis. The mean age of the cohort was 27.8 ± 6.8 years. Kaplan fiber injuries were identified in 51 of 131 (38.9%, CI 31.0-47.5%) scans with complete anterior cruciate ligament injuries (Grade 1: 28, Grade 2: 18, and Grade 3: 5). Inter-rater agreement for Kaplan fiber injury was fair ([Formula: see text] with 43 (32.8%) scans requiring third reviewer adjudication. There were no significant associations between Kaplan fiber injury and gender, magnet strength, meniscal tears, or posterolateral tibial bone bruise. CONCLUSION: The prevalence of Kaplan fiber injuries was comparable to previously described rates; however, the classification system used to report Kaplan fiber injury was associated with low inter-rater reliability. The presence of Kaplan fiber injury was not associated with other injuries commonly observed in conjunction with ACL tear. The previously proposed Kaplan fiber injury classification system is not reproducible nor is it likely to aid surgeons in distinguishing higher grades of rotatory knee instability. LEVEL OF EVIDENCE: Level IV.

Amino terminus of cardiac myosin binding protein-C regulates cardiac contractility.

Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) regulates cardiac contraction through modulation of actomyosin interactions mediated by the protein's amino terminal (N')-region (C0-C2 domains, 358 amino acids). On the other hand, dephosphorylation of cMyBP-C during myocardial injury results in cleavage of the 271 amino acid C0-C1f region and subsequent contractile dysfunction. Yet, our current understanding of amino terminus region of cMyBP-C in the context of regulating thin and thick filament interactions is limited. A novel cardiac-specific transgenic mouse model expressing cMyBP-C, but lacking its C0-C1f region (cMyBP-C∆C0-C1f), displayed dilated cardiomyopathy, underscoring the importance of the N'-region in cMyBP-C. Further exploring the molecular basis for this cardiomyopathy, in vitro studies revealed increased interfilament lattice spacing and rate of tension redevelopment, as well as faster actin-filament sliding velocity within the C-zone of the transgenic sarcomere. Moreover, phosphorylation of the unablated phosphoregulatory sites was increased, likely contributing to normal sarcomere morphology and myoarchitecture. These results led us to hypothesize that restoration of the N'-region of cMyBP-C would return actomyosin interaction to its steady state. Accordingly, we administered recombinant C0-C2 (rC0-C2) to permeabilized cardiomyocytes from transgenic, cMyBP-C null, and human heart failure biopsies, and we found that normal regulation of actomyosin interaction and contractility was restored. Overall, these data provide a unique picture of selective perturbations of the cardiac sarcomere that either lead to injury or adaptation to injury in the myocardium.

Rate of venous thromboembolism after surgical treatment of proximal humerus fractures.

INTRODUCTION: The rate of venous thromboembolism following surgical treatment of proximal humerus fractures is not well established. METHODS: A retrospective review of all patients undergoing surgical treatment for proximal humerus fractures from September 2011 to May 2017 was performed. Included patients received only mechanoprophylaxis using sequential compression devises. All patients had at least 6 months follow-up. The primary outcome of interest was the rate of postoperative DVT and PE. RESULTS: 131 patients underwent 139 surgeries for proximal humerus fracture. After exclusion criteria were applied, 92 patients who underwent 92 surgeries were included. There were 47 females and 45 males. Five (5.4%) were taking Aspirin 81 mg preoperatively. There were 76 cases of open reduction and internal fixation (ORIF), 8 cases of reverse total shoulder arthroplasty, 4 cases of hemiarthroplasty, 3 cases of closed reduction percutaneous pinning (CRPP), 1 case of open reduction without fixation. 53.3% of patients had one or more risk factors for VTE. There were no cases of fatal PE or DVT. There were two cases of symptomatic PE (2.2%) following one ORIF and one CRPP. There was one additional case of asymptomatic PE found incidentally after ORIF. Overall VTE rate was 3.3%. Fisher's exact test yielded that there was no significant association between the presence of VTE risk factors and prevalence of VTE postoperatively (p = 0.245). CONCLUSIONS: The incidence of symptomatic VTE after surgery for proximal humerus fractures is low. Chemical VTE prophylaxis in patients after surgical fixation for proximal humerus fractures is not universally indicated. Selective prophylaxis for patients with systemic risk factors may be warranted.

Derivation of induced pluripotent stem cells from ferret somatic cells.

Ferrets are an attractive mammalian model for several diseases, especially those affecting the lungs, liver, brain, and kidneys. Many chronic human diseases have been difficult to model in rodents due to differences in size and cellular anatomy. This is particularly the case for the lung, where ferrets provide an attractive mammalian model of both acute and chronic lung diseases, such as influenza, cystic fibrosis, A1A emphysema, and obliterative bronchiolitis, closely recapitulating disease pathogenesis, as it occurs in humans. As such, ferrets have the potential to be a valuable preclinical model for the evaluation of cell-based therapies for lung regeneration and, likely, for other tissues. Induced pluripotent stem cells (iPSCs) provide a great option for provision of enough autologous cells to make patient-specific cell therapies a reality. Unfortunately, they have not been successfully created from ferrets. In this study, we demonstrate the generation of ferret iPSCs that reflect the primed pluripotent state of human iPSCs. Ferret fetal fibroblasts were reprogrammed and acquired core features of pluripotency, having the capacity for self-renewal, multilineage differentiation, and a high-level expression of the core pluripotency genes and pathways at both the transcriptional and protein level. In conclusion, we have generated ferret pluripotent stem cells that provide an opportunity for advancing our capacity to evaluate autologous cell engraftment in ferrets.

Refractory depression - mechanisms and efficacy of radically open dialectical behaviour therapy (RefraMED): findings of a randomised trial on benefits and harms.

BACKGROUND: Individuals with depression often do not respond to medication or psychotherapy. Radically open dialectical behaviour therapy (RO DBT) is a new treatment targeting overcontrolled personality, common in refractory depression. AIMS: To compare RO DBT plus treatment as usual (TAU) for refractory depression with TAU alone (trial registration: ISRCTN 85784627). METHOD: RO DBT comprised 29 therapy sessions and 27 skills classes over 6 months. Our completed randomised trial evaluated RO DBT for refractory depression over 18 months in three British secondary care centres. Of 250 adult participants, we randomised 162 (65%) to RO DBT. The primary outcome was the Hamilton Rating Scale for Depression (HRSD), assessed masked and analysed by treatment allocated. RESULTS: After 7 months, immediately following therapy, RO DBT had significantly reduced depressive symptoms by 5.40 points on the HRSD relative to TAU (95% CI 0.94-9.85). After 12 months (primary end-point), the difference of 2.15 points on the HRSD in favour of RO DBT was not significant (95% CI -2.28 to 6.59); nor was that of 1.69 points on the HRSD at 18 months (95% CI -2.84 to 6.22). Throughout RO DBT participants reported significantly better psychological flexibility and emotional coping than controls. However, they reported eight possible serious adverse reactions compared with none in the control group. CONCLUSIONS: The RO DBT group reported significantly lower HRSD scores than the control group after 7 months, but not thereafter. The imbalance in serious adverse reactions was probably because of the controls' limited opportunities to report these.

A risk calculator to inform the need for a prostate biopsy: a rapid access clinic cohort.

BACKGROUND: Prostate cancer (PCa) represents a significant healthcare problem. The critical clinical question is the need for a biopsy. Accurate risk stratification of patients before a biopsy can allow for individualised risk stratification thus improving clinical decision making. This study aims to build a risk calculator to inform the need for a prostate biopsy. METHODS: Using the clinical information of 4801 patients an Irish Prostate Cancer Risk Calculator (IPRC) for diagnosis of PCa and high grade (Gleason ≥7) was created using a binary regression model including age, digital rectal examination, family history of PCa, negative prior biopsy and Prostate-specific antigen (PSA) level as risk factors. The discrimination ability of the risk calculator is internally validated using cross validation to reduce overfitting, and its performance compared with PSA and the American risk calculator (PCPT), Prostate Biopsy Collaborative Group (PBCG) and European risk calculator (ERSPC) using various performance outcome summaries. In a subgroup of 2970 patients, prostate volume was included. Separate risk calculators including the prostate volume (IPRCv) for the diagnosis of PCa (and high-grade PCa) was created. RESULTS: IPRC area under the curve (AUC) for the prediction of PCa and high-grade PCa was 0.6741 (95% CI, 0.6591 to 0.6890) and 0.7214 (95% CI, 0.7018 to 0.7409) respectively. This significantly outperforms the predictive ability of cancer detection for PSA (0.5948), PCPT (0.6304), PBCG (0.6528) and ERSPC (0.6502) risk calculators; and also, for detecting high-grade cancer for PSA (0.6623) and PCPT (0.6804) but there was no significant improvement for PBCG (0.7185) and ERSPC (0.7140). The inclusion of prostate volume into the risk calculator significantly improved the AUC for cancer detection (AUC = 0.7298; 95% CI, 0.7119 to 0.7478), but not for high-grade cancer (AUC = 0.7256; 95% CI, 0.7017 to 0.7495). The risk calculator also demonstrated an increased net benefit on decision curve analysis. CONCLUSION: The risk calculator developed has advantages over prior risk stratification of prostate cancer patients before the biopsy. It will reduce the number of men requiring a biopsy and their exposure to its side effects. The interactive tools developed are beneficial to translate the risk calculator into practice and allows for clarity in the clinical recommendations.