Computed Tomography Scan Versus Saline Load Test in the Detection of Traumatic Arthrotomies of the Ankle: A Cadaveric Study.

OBJECTIVE: To evaluate the sensitivity and ability of computed tomography (CT) scan for diagnosing traumatic ankle arthrotomies compared with that of the saline load test (SLT). METHODS: Eleven cadaveric ankles were included in this study. Before intervention, a CT scan was obtained to confirm the absence of intra-articular air. Arthrotomies were created at the anterolateral, posterolateral, anteromedial, and posteromedial aspects of the ankle under fluoroscopic visualization. A postarthrotomy and postrange of motion CT scan was obtained to evaluate for the presence of intra-articular air. Each ankle then underwent a SLT with 60 mL of saline, where volumes provoking extravasation were recorded. RESULTS: Of the 11 included ankles, intra-articular air was detected in all 11 ankles by CT scan. All 11 ankles also demonstrated extravasation of saline through the arthrotomy site during SLT. Thus, the sensitivity for both CT scan and SLT for detecting ankle traumatic arthrotomy was 100%. The mean volume of saline needed for extravasation was 7.7 mL, with a range of 3-22 mL and a SD of 5.4. CONCLUSIONS: Given that CT scan was equally as sensitive to the SLT, this study presents good evidence that CT scan may be used for the detection of ankle traumatic arthrotomies.

PARP14 inhibition restores PD-1 immune checkpoint inhibitor response following IFNγ-driven acquired resistance in preclinical cancer models.

Resistance mechanisms to immune checkpoint blockade therapy (ICBT) limit its response duration and magnitude. Paradoxically, Interferon γ (IFNγ), a key cytokine for cellular immunity, can promote ICBT resistance. Using syngeneic mouse tumour models, we confirm that chronic IFNγ exposure confers resistance to immunotherapy targeting PD-1 (α-PD-1) in immunocompetent female mice. We observe upregulation of poly-ADP ribosyl polymerase 14 (PARP14) in chronic IFNγ-treated cancer cell models, in patient melanoma with elevated IFNG expression, and in melanoma cell cultures from ICBT-progressing lesions characterised by elevated IFNγ signalling. Effector T cell infiltration is enhanced in tumours derived from cells pre-treated with IFNγ in immunocompetent female mice when PARP14 is pharmacologically inhibited or knocked down, while the presence of regulatory T cells is decreased, leading to restoration of α-PD-1 sensitivity. Finally, we determine that tumours which spontaneously relapse in immunocompetent female mice following α-PD-1 therapy upregulate IFNγ signalling and can also be re-sensitised upon receiving PARP14 inhibitor treatment, establishing PARP14 as an actionable target to reverse IFNγ-driven ICBT resistance.

Intralabial Lip Compartments and their Potential Clinical Relevance.

BACKGROUND: Aesthetic soft tissue filler injections for lip enhancement are highly popular and are performed throughout the world. When injecting lips with cannulas, as the cannula is advanced, resistance is perceived in consistent locations potentially indicating boundaries between intralabial compartments. OBJECTIVE: To investigate whether intra-labial compartments exist and (if so) to describe their volumes, location, boundaries, and dimensions. METHODS: This cadaveric study investigated a total of n = 20 (13 males, 7 females) human body donors with a mean age at death of 61.9 (23.9) years and a mean body mass index of 24.3 (3.7) kg/m 2. The investigated cohort included n = 11 Caucasian, n = 8 Asian, and n = 1 African American donors. Dye injections simulating minimally invasive lip treatments were conducted. RESULTS: Independent of gender or race, 6 anterior and 6 posterior compartments in the upper and lower lip were identified, for a total of 24 lip compartments. Compartment boundaries were formed by vertically oriented septations that were found in consistent locations. The anterior compartments had volumes ranging from 0.30 - 0.39 cc whereas the posterior compartment volume ranged from 0.44 - 0.52 cc. Centrally, the compartment volumes were larger and decreased gradually towards the oral commissure. CONCLUSION: The volume and the size of each of the 24 compartments contribute to the overall appearance and shape of the lips. To achieve a natural and lip-shape preserving aesthetic outcome it may be preferable to administer the volumizing product using a compartment-respecting injection approach.

Clinical Factors Impacting Outcomes From Failed Trabeculectomy Leading to Glaucoma Drainage Device Implantation and Subsequent Penetrating Keratoplasty.

PRCIS: We evaluated the factors that impacted time from glaucoma drainage implant (GDI) surgery to penetrating keratoplasty (PK) in eyes with previously clear corneas (ie, GDI-first sequence), and that specifically underwent a trabeculectomy before GDI surgery for intraocular pressure (IOP) control. PURPOSE: To describe through an event-triggered data collection method the clinical course and the long-term outcomes of 2 procedures that are commonly performed sequentially in complex clinical situations: GDI surgery and PK. The study investigates the clinical factors associated with the progression to PK and determines the GDI success rate and graft survival. METHODS: A single, tertiary-care center retrospective interventional cases series including patients with a sequential history of trabeculectomy, GDI surgery, and PK from 1999 to 2009. Outcome measures included IOP, visual acuity, graft failure, GDI failure, and time from GDI to PK. RESULTS: Of the eyes, 56% had primary open angle glaucoma. The time from the last trabeculectomy to GDI was 66.5 ± 66.7 months. Of the eyes, 84% received a Baerveldt GDI. Time from GDI to PK was 36.4 ± 28.4 months. IOP at the time of PK was between 5 mm Hg and 21 mm Hg in 90% of eyes. At the last follow-up, 48% of grafts were clear. At 5 years post-PK, 33% of corneal grafts remained clear, whereas 81% of tubes remained functional. CONCLUSIONS: Nearly half of the corneal grafts are clear at the last long-term follow-up. Graft failure occurs at a higher rate than tube failure suggesting that IOP control is only one and possibly not the most important factor in graft survival in eyes with prior glaucoma surgery.

Computed Tomography Scan Versus Saline Load Test for Detection of Traumatic Shoulder Arthrotomy: A Cadaveric Study.

OBJECTIVES: Traumatic shoulder arthrotomy (TSA) is a rare injury that is commonly detected through saline load test (SLT). There are no studies that have studied the ability of computed tomography (CT) scan to detect a TSA. The purpose of this study is to determine the ability of CT scan to detect a TSA and compare it with the SLT. METHODS: Twelve cadaveric shoulders were included in the study. Before intervention, a CT scan was conducted to determine presence of intra-articular air. After confirmation that no air was present, an arthrotomy was made at the anterior or posterior portal site. A CT was obtained postarthrotomy to evaluate for intra-articular air. Each shoulder then underwent an SLT to assess the sensitivity of SLT and the volume needed for extravasation. RESULTS: Twelve shoulders were included after a pre-intervention CT scan. Six shoulders received an arthrotomy through the anterior portal and six shoulders received an arthrotomy through the posterior portal. After the arthrotomy, air was visualized on CT scan in 11 of the 12 shoulders (92%). All 12 shoulders demonstrated extravasation during SLT. The mean volume of saline needed for extravasation was 29 mL with an SD of 10 and range of 18-50 mL. CONCLUSIONS: CT scan is a sensitive modality (sensitivity of 92%) for detection of TSA. In comparison, SLT is more sensitive (sensitivity of 100%) and outperforms CT scan for the diagnosis of TSA in a cadaveric model. Further research is needed to solidify the role that CT imaging has in the diagnosis of TSAs.

Measurement of the gluteal compartment pressures: A cadaveric study describing safety and reproducibility of two methods.

INTRODUCTION: Gluteal compartment syndrome is an uncommon entity and physicians may use intracompartmental pressure measurements for confirmation of the clinical diagnosis, or in cases where the physical exam is indeterminate. However, there is a paucity of literature describing a safe and reproducible technique to measure gluteal intracompartmental pressures during the diagnosis of gluteal compartment syndrome. The purpose of this cadaveric study is to evaluate the sole previous technique described in the literature to measure gluteal intracompartmental pressures and provide a modified technique which can be safely and reliably utilized clinically. METHODS: A cadaveric study with three phases was performed in 16 gluteal regions in 8 cadavers. In the first phase, the previously described technique was assessed. In the second phase, a modified set of techniques was created and evaluated. In the third phase, inter-user reliability of the modified set of techniques was assessed and calculated using Cohen's ĸ coefficient. In all three phases, methylene blue was injected through pressure monitoring needles into the gluteus maximus (GMax), gluteus medius/minimus (GMM), and the tensor fascia lata (TFL) compartments. Following dissection, rate of successful penetration into each targeted compartment and distance from the neurovascular structures was recorded. RESULTS: The previously described set of techniques was found to be variable. The modified set of techniques was effective, successfully reaching the GMax, GMM, and TFL compartments in 100%, 100%, and 81% of attempts, respectively. Inter-user reliability was excellent (ĸ = 1) for the techniques to reach both the GMax and GMM compartments, and moderate (ĸ = 0.54) for the technique to reach the TFL compartment. Within the GMax, the pressure monitoring needle was at a mean of 5.4±0.6 cm, 4.1±0.7 cm, 6.4±0.5 cm from the sciatic nerve (SN), superior gluteal nerve (SGN), and inferior gluteal nerve (IGN), respectively. Within the GMM, the pressure monitoring needle was at a mean of 9.7±1.4 cm, 7.4±1.3 cm, 11.1±1.7 cm from the SN, SGN, and IGN, respectively. CONCLUSION: The modified set of techniques presented allows the three gluteal compartments to be safely and reproducibly reached to measure intracompartmental pressures during the diagnosis of gluteal compartment syndrome.

Exploring the Value of Improvisational Theater in Medical Education for Advancing the Doctor-Patient Relationship and Health Equity.

PURPOSE: Health care inequities persist, and it is difficult to teach health professions students effectively about implicit bias, structural inequities, and caring for patients from underrepresented or minoritized backgrounds. Improvisational theater (improv), where performers create everything in a spontaneous and unplanned manner, may help teach health professions trainees about advancing health equity. Core improv skills, discussion, and self-reflection can help improve communication; build trustworthy relationships with patients; and address bias, racism, oppressive systems, and structural inequities. METHOD: Authors integrated a 90-minute virtual improv workshop using basic exercises into a required course for first-year medical students at University of Chicago in 2020. Sixty randomly chosen students took the workshop and 37 (62%) responded to Likert-scale and open-ended questions about strengths, impact, and areas for improvement. Eleven students participated in structured interviews about their experience. RESULTS: Twenty-eight (76%) of 37 students rated the workshop as very good or excellent, and 31 (84%) would recommend it to others. Over 80% of students perceived their listening and observation skills improved, and that the workshop would help them take better care of patients with experiences different than their own. Six (16%) students experienced stress during the workshop but 36 (97%) felt safe. Eleven (30%) students agreed there were meaningful discussions about systemic inequities. Qualitative interview analysis showed that students thought the workshop helped develop interpersonal skills (communication, relationship building, empathy); helped personal growth (insights into perception of self and others, ability to adapt to unexpected situations); and felt safe. Students noted the workshop helped them to be in the moment with patients and respond to the unexpected in ways more traditional communication curricula have not. The authors developed a conceptual model relating improv skills and equity teaching methods to advancing health equity. CONCLUSIONS: Improv theater exercises can complement traditional communication curricula to advance health equity.

Spatially resolved phosphoproteomics reveals fibroblast growth factor receptor recycling-driven regulation of autophagy and survival.

Receptor Tyrosine Kinase (RTK) endocytosis-dependent signalling drives cell proliferation and motility during development and adult homeostasis, but is dysregulated in diseases, including cancer. The recruitment of RTK signalling partners during endocytosis, specifically during recycling to the plasma membrane, is still unknown. Focusing on Fibroblast Growth Factor Receptor 2b (FGFR2b) recycling, we reveal FGFR signalling partners proximal to recycling endosomes by developing a Spatially Resolved Phosphoproteomics (SRP) approach based on APEX2-driven biotinylation followed by phosphorylated peptides enrichment. Combining this with traditional phosphoproteomics, bioinformatics, and targeted assays, we uncover that FGFR2b stimulated by its recycling ligand FGF10 activates mTOR-dependent signalling and ULK1 at the recycling endosomes, leading to autophagy suppression and cell survival. This adds to the growing importance of RTK recycling in orchestrating cell fate and suggests a therapeutically targetable vulnerability in ligand-responsive cancer cells. Integrating SRP with other systems biology approaches provides a powerful tool to spatially resolve cellular signalling.

Determining presentation skills gaps among healthcare professionals.

Healthcare professionals frequently communicate complex medical information among colleagues and students. This paper aims to determine gaps in healthcare professionals' presentation skills and identify barriers to improving. Eighty-eight individuals at a Midwest Academic Medical Center completed a survey that consisted of three parts: (1) respondents' current presentation slide deck, (2) respondents' perceptions of their current presentation skills, and (3) barriers to and motivations for improving their presentation skills. A mixed-methods approach was used to collect and analyze data. Respondents used bullet points and text the most (74%), and videos the least in their presentations (51%). When assessing respondents' perceptions of their current presentation skills, they rated themselves the lowest as a storyteller (median = 6/10) and as an overall presenter (median = 6/10). The biggest barrier reported was "lack of training on best practices" (58%). Respondents reported "interested in improving" and "enhance opportunities" as their main motivations for improving presentation skills. Four themes emerged from the open-ended survey items: Practical tips and best practices, Ability to communicate effectively, Professional development, and Practice opportunities. Effective presentation skills should be included in every healthcare professionals faculty development curriculum. This is especially crucial for junior faculty members to ensure their continued success.

Impact of Pharmacists to Improve Patient Care in the Critically Ill: A Large Multicenter Analysis Using Meaningful Metrics With the Medication Regimen Complexity-ICU (MRC-ICU) Score.

OBJECTIVES: Despite the established role of the critical care pharmacist on the ICU multiprofessional team, critical care pharmacist workloads are likely not optimized in the ICU. Medication regimen complexity (as measured by the Medication Regimen Complexity-ICU [MRC-ICU] scoring tool) has been proposed as a potential metric to optimize critical care pharmacist workload but has lacked robust external validation. The purpose of this study was to test the hypothesis that MRC-ICU is related to both patient outcomes and pharmacist interventions in a diverse ICU population. DESIGN: This was a multicenter, observational cohort study. SETTING: Twenty-eight ICUs in the United States. PATIENTS: Adult ICU patients. INTERVENTIONS: Critical care pharmacist interventions (quantity and type) on the medication regimens of critically ill patients over a 4-week period were prospectively captured. MRC-ICU and patient outcomes (i.e., mortality and length of stay [LOS]) were recorded retrospectively. MEASUREMENTS AND MAIN RESULTS: A total of 3,908 patients at 28 centers were included. Following analysis of variance, MRC-ICU was significantly associated with mortality (odds ratio, 1.09; 95% CI, 1.08-1.11; p < 0.01), ICU LOS (ß coefficient, 0.41; 95% CI, 00.37-0.45; p < 0.01), total pharmacist interventions (ß coefficient, 0.07; 95% CI, 0.04-0.09; p < 0.01), and a composite intensity score of pharmacist interventions (ß coefficient, 0.19; 95% CI, 0.11-0.28; p < 0.01). In multivariable regression analysis, increased patient: pharmacist ratio (indicating more patients per clinician) was significantly associated with increased ICU LOS (ß coefficient, 0.02; 0.00-0.04; p = 0.02) and reduced quantity (ß coefficient, -0.03; 95% CI, -0.04 to -0.02; p < 0.01) and intensity of interventions (ß coefficient, -0.05; 95% CI, -0.09 to -0.01). CONCLUSIONS: Increased medication regimen complexity, defined by the MRC-ICU, is associated with increased mortality, LOS, intervention quantity, and intervention intensity. Further, these results suggest that increased pharmacist workload is associated with decreased care provided and worsened patient outcomes, which warrants further exploration into staffing models and patient outcomes.

Human Melanoma-Associated Mast Cells Display a Distinct Transcriptional Signature Characterized by an Upregulation of the Complement Component 3 That Correlates With Poor Prognosis.

Cutaneous melanoma is one of the most aggressive human malignancies and shows increasing incidence. Mast cells (MCs), long-lived tissue-resident cells that are particularly abundant in human skin where they regulate both innate and adaptive immunity, are associated with melanoma stroma (MAMCs). Thus, MAMCs could impact melanoma development, progression, and metastasis by secreting proteases, pro-angiogenic factors, and both pro-inflammatory and immuno-inhibitory mediators. To interrogate the as-yet poorly characterized role of human MAMCs, we have purified MCs from melanoma skin biopsies and performed RNA-seq analysis. Here, we demonstrate that MAMCs display a unique transcriptome signature defined by the downregulation of the FcεRI signaling pathway, a distinct expression pattern of proteases and pro-angiogenic factors, and a profound upregulation of complement component C3. Furthermore, in melanoma tissue, we observe a significantly increased number of C3+ MCs in stage IV melanoma. Moreover, in patients, C3 expression significantly correlates with the MC-specific marker TPSAB1, and the high expression of both markers is linked with poorer melanoma survival. In vitro, we show that melanoma cell supernatants and tumor microenvironment (TME) mediators such as TGF-ß, IL-33, and IL-1ß induce some of the changes found in MAMCs and significantly modulate C3 expression and activity in MCs. Taken together, these data suggest that melanoma-secreted cytokines such as TGF-ß and IL-1ß contribute to the melanoma microenvironment by upregulating C3 expression in MAMCs, thus inducing an MC phenotype switch that negatively impacts melanoma prognosis.

Oxidative stress from DGAT1 oncoprotein inhibition in melanoma suppresses tumor growth when ROS defenses are also breached.

Dysregulated cellular metabolism is a cancer hallmark for which few druggable oncoprotein targets have been identified. Increased fatty acid (FA) acquisition allows cancer cells to meet their heightened membrane biogenesis, bioenergy, and signaling needs. Excess FAs are toxic to non-transformed cells but surprisingly not to cancer cells. Molecules underlying this cancer adaptation may provide alternative drug targets. Here, we demonstrate that diacylglycerol O-acyltransferase 1 (DGAT1), an enzyme integral to triacylglyceride synthesis and lipid droplet formation, is frequently up-regulated in melanoma, allowing melanoma cells to tolerate excess FA. DGAT1 over-expression alone transforms p53-mutant zebrafish melanocytes and co-operates with oncogenic BRAF or NRAS for more rapid melanoma formation. Antagonism of DGAT1 induces oxidative stress in melanoma cells, which adapt by up-regulating cellular reactive oxygen species defenses. We show that inhibiting both DGAT1 and superoxide dismutase 1 profoundly suppress tumor growth through eliciting intolerable oxidative stress.

Fibroblast Growth Factor Receptors (FGFRs) and Noncanonical Partners in Cancer Signaling.

Increasing evidence indicates that success of targeted therapies in the treatment of cancer is context-dependent and is influenced by a complex crosstalk between signaling pathways and between cell types in the tumor. The Fibroblast Growth Factor (FGF)/FGF receptor (FGFR) signaling axis highlights the importance of such context-dependent signaling in cancer. Aberrant FGFR signaling has been characterized in almost all cancer types, most commonly non-small cell lung cancer (NSCLC), breast cancer, glioblastoma, prostate cancer and gastrointestinal cancer. This occurs primarily through amplification and over-expression of FGFR1 and FGFR2 resulting in ligand-independent activation. Mutations and translocations of FGFR1-4 are also identified in cancer. Canonical FGF-FGFR signaling is tightly regulated by ligand-receptor combinations as well as direct interactions with the FGFR coreceptors heparan sulfate proteoglycans (HSPGs) and Klotho. Noncanonical FGFR signaling partners have been implicated in differential regulation of FGFR signaling. FGFR directly interacts with cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins, contributing to invasive and migratory properties of cancer cells, whereas interactions with other receptor tyrosine kinases (RTKs) regulate angiogenic, resistance to therapy, and metastatic potential of cancer cells. The diversity in FGFR signaling partners supports a role for FGFR signaling in cancer, independent of genetic aberration.

Reciprocal priming between receptor tyrosine kinases at recycling endosomes orchestrates cellular signalling outputs.

Integration of signalling downstream of individual receptor tyrosine kinases (RTKs) is crucial to fine-tune cellular homeostasis during development and in pathological conditions, including breast cancer. However, how signalling integration is regulated and whether the endocytic fate of single receptors controls such signalling integration remains poorly elucidated. Combining quantitative phosphoproteomics and targeted assays, we generated a detailed picture of recycling-dependent fibroblast growth factor (FGF) signalling in breast cancer cells, with a focus on distinct FGF receptors (FGFRs). We discovered reciprocal priming between FGFRs and epidermal growth factor (EGF) receptor (EGFR) that is coordinated at recycling endosomes. FGFR recycling ligands induce EGFR phosphorylation on threonine 693. This phosphorylation event alters both FGFR and EGFR trafficking and primes FGFR-mediated proliferation but not cell invasion. In turn, FGFR signalling primes EGF-mediated outputs via EGFR threonine 693 phosphorylation. This reciprocal priming between distinct families of RTKs from recycling endosomes exemplifies a novel signalling integration hub where recycling endosomes orchestrate cellular behaviour. Therefore, targeting reciprocal priming over individual receptors may improve personalized therapies in breast and other cancers.

Signal-To-Noise Ratio Calculations to Validate Sensor Positioning for Facial Muscle Assessment Using Noninvasive Facial Electromyography.

The evaluation of neuromodulator treatment outcomes can be performed by noninvasive surface-derived facial electromyography (fEMG) which can detect cumulative muscle fiber activity deep to the skin. The objective of the present study is to identify the most reliable facial locations where the motor unit action potentials (MUAPs) of various facial muscles can be quantified during fEMG measurements. The study population consisted of five males and seven females (31.0 [12.9] years, body mass index of 22.15 [1.6] kg/m2). Facial muscle activity was assessed in several facial regions in each patient for their respective muscle activity utilizing noninvasive surface-derived fEMG. Variables of interest were the average root mean square of three performed muscle contractions (= signal) (µV), mean root mean square between those contraction with the face in a relaxed facial expression (= baseline noise) (µV), and the signal to noise ratio (SNR). A total of 1,709 processed fEMG signals revealed one specific reliable location in each investigated region based on each muscle's anatomy, on the highest value of the SNR, on the lowest value for the baseline noise, and on the practicability to position the sensor while performing a facial expression. The results of this exploratory study may help guiding future researchers and practitioners in designing study protocols and measuring individual facial MUAP when utilizing fEMG. The locations presented herein were selected based on the measured parameters (SNR, signal, baseline noise) and on the practicability and reproducibility of sensor placement.

Anatomy of the Dorsum of the Foot and Its Relevance for Nonsurgical Cosmetic Procedures.

BACKGROUND: Operative procedures to enhance the aesthetic appearance of the feet are associated with risks. Minimally invasive procedures to volumize the dorsum of the foot are to this point not described. The present study investigates the safety and efficacy of such procedures in a retrospective clinical, anatomical, and ultrasound-based study. METHODS: A total of 106 feet from 53 female patients (mean age, 64.1 ± 8.3 years) were investigated retrospectively after the injection of a commercially available calcium hydroxylapatite product using a single-entry proximal-to-distal fanning injection technique. Anatomical dissections in 20 fresh, nonembalmed feet from 10 human body donors (mean age, 83.1 ± 8.8 years) were dissected, and 20 feet from 10 healthy volunteers (mean age, 26.5 ± 6.2 years) were examined by ultrasound imaging to help guide conclusions. RESULTS: Aesthetic outcome after 3 months was graded by the patients as 4, connoting good improvement (range, 3 to 5). No allergic reactions or other types of adverse events were documented. The layered anatomy of the dorsum of the foot was confirmed by anatomical dissections and ultrasound imaging as follows: skin, dorsal superficial fatty layer, dorsal superficial fascia, dorsal intermediate fatty layer, superficial lamina of the dorsal deep fascia, dorsal deep fatty layer, and deep lamina of the dorsal deep fascia. CONCLUSIONS: Minimally invasive injections of soft-tissue filler in the dorsum of the foot can provide an alternate solution to enhance the aesthetic appearance of feet. The present study provides support for the safety and efficacy of volumizing procedures using a 22-gauge, 50-mm, blunt-tip cannula. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Discovery of a Gatekeeper Residue in the C-Terminal Tail of the Extracellular Signal-Regulated Protein Kinase 5 (ERK5).

The extracellular signal-regulated protein kinase 5 (ERK5) is a non-redundant mitogen-activated protein kinase (MAPK) that exhibits a unique C-terminal extension which comprises distinct structural and functional properties. Here, we sought to elucidate the significance of phosphoacceptor sites in the C-terminal transactivation domain of ERK5. We have found that Thr732 acted as a functional gatekeeper residue controlling C-terminal-mediated nuclear translocation and transcriptional enhancement. Consistently, using a non-bias quantitative mass spectrometry approach, we demonstrated that phosphorylation at Thr732 conferred selectivity for binding interactions of ERK5 with proteins related to chromatin and RNA biology, whereas a number of metabolic regulators were associated with full-length wild type ERK5. Additionally, our proteomic analysis revealed that phosphorylation of the Ser730-Glu-Thr732-Pro motif could occur independently of dual phosphorylation at Thr218-Glu-Tyr220 in the activation loop. Collectively, our results firmly establish the significance of C-terminal phosphorylation in regulating ERK5 function. The post-translational modification of ERK5 on its C-terminal tail might be of particular relevance in cancer cells where ERK5 has be found to be hyperphosphoryated.

Blind nasogastric tube advancement following sleeve gastrectomy: an animal model.

BACKGROUND: Sleeve gastrectomy is an effective surgical treatment for morbid obesity. The major technical risk of this procedure is staple line dehiscence. Some surgeons are reluctant to place a nasogastric tube (NGT) blindly due to the perceived risk of damage to the staple line. We sought to determine whether such concern was warranted. METHODS: A porcine tissue model (Animal Technologies, Inc., Tyler, TX) was used. Sleeve gastrectomy was performed using a flexible gastroscope as a guide for the Endo GIA stapler (Covidien, New Haven, CT) in an identical fashion used in our patients. The specimen was then placed in a plastic model of the thorax (VATS Trainers, LLC. Lansing, MI). The NGT was blindly advanced to 55 cm for a total of 50 passes, and to 75 cm for another 50 passes. Endoscopy with water submersion was performed to evaluate for injury or leak. RESULTS: After multiple passes of the NGT, no significant injuries, leaks, or perforations were observed to the gastric model, except for several small petechiae of the gastric mucosa, the largest measuring approximately 3 mm. None were of full thickness or penetrated the mucosa. The staple line showed no evidence of trauma. CONCLUSION: In this porcine model, blind NGT placement was not associated with significant mucosal injury or any damage to the sleeve gastrectomy staple line.

Osteoblasts contribute to a protective niche that supports melanoma cell proliferation and survival.

Melanoma is the deadliest form of skin cancer; a primary driver of this high level of morbidity is the propensity of melanoma cells to metastasize. When malignant tumours develop distant metastatic lesions the new local tissue niche is known to impact on the biology of the cancer cells. However, little is known about how different metastatic tissue sites impact on frontline targeted therapies. Intriguingly, melanoma bone lesions have significantly lower response to BRAF or MEK inhibitor therapies. Here, we have investigated how the cellular niche of the bone can support melanoma cells by stimulating growth and survival via paracrine signalling between osteoblasts and cancer cells. Melanoma cells can enhance the differentiation of osteoblasts leading to increased production of secreted ligands, including RANKL. Differentiated osteoblasts in turn can support melanoma cell proliferation and survival via the secretion of RANKL that elevates the levels of the transcription factor MITF, even in the presence of BRAF inhibitor. By blocking RANKL signalling, either via neutralizing antibodies, genetic alterations or the RANKL receptor inhibitor SPD304, the survival advantage provided by osteoblasts could be overcome.

Ethnic differences in platysmal perforators and its relevance for the platysma myocutaneous flap.

BACKGROUND: Variable flap loss rates for the platysma myocutaneous flap have been reported for the Caucasian and the Asian population, which are 10.1% and 1.6%, respectively. This study was designed to investigate ethnic differences in the number and location of platysmal perforators that influence flap survival rates. METHODS: The number and location of platysmal perforators were investigated in a total of 60 platysma muscles: bilaterally in 20 Caucasian (13 males and 7 females) and 10 Asian (5 males and 5 females) specimens using cadaveric dissections. Adjustment for inter-individual variability in platysma length and width was performed by standardizing each x-value to mandibular length and each y-value to mandibulo-clavicular distance. RESULTS: A total of 64% of all detected platysmal perforators were found in the medial half of the muscle following the pathway of the external carotid artery. Individuals of Caucasian ethnicity had a mean number of 7.60 ± 2.0 perforators per side, whereas individuals of Asian ethnicity had a mean number of 13.05 ± 1.76 perforators per side (p < 0.001). Individuals of Asian ethnicity had a statistically significant increased number of platysmal perforators in the medial middle (2.95 ± 1.05 vs. 1.60 ± 1.08; p < 0.001) and lower (1.60 ± 1.35 vs. 0.73 ± 0.85; p = 0.003) regions of the platysma compared to those of Caucasian individuals. CONCLUSION: A significantly higher number of platysmal perforators were identified in the investigated Asian population. This provides a potential explanatory model for the reported lower platysma myocutaneous flap loss rates in the Asian population than in the Caucasian population.