Purification of Cortactin Using Anion Exchange Chromatography

Cortactin is an actin-binding protein that has been shown to be involved in cellular migration and metastases in cancer. Bacterially expressed and purified cortactin protein is often used in in vitro assays to examine cortactin’s role in promoting cell migration via actin remodeling. Cortactin has a theoretical molecular weight of 60 kDa; however, using SDS-PAGE analysis, the protein runs as two bands of molecular weights 80 kDa and 85 kDa, suggesting that cortactin has an unusual protein folding pattern. Our current lack of understanding of cortactin structure limits our ability to determine the role of cortactin in facilitating motility phenotypes. To elucidate the forms of cortactin produced from bacterially expressed and purified cortactin protein, we used a two-step purification system including affinity purification and anion exchange chromatography. After analysis with non-denaturing polyacrylamide gel electrophoresis, we found cortactin protein from different anion chromatography elution fractions did not separate to similar locations on the gel across all fractions. We hypothesize that the variations in the bands are a result of different folding patterns of cortactin protein in what was once thought of as a homogenous protein pool. When testing the role of cortactin in mediating cell migration, these folding differences may have significant effects on the results of functional assays such as actin polymerization or sedimentation

Three Students, Three Paths

Three students share the different paths they have taken in completing their Linfield journey – through study abroad, internships and athletics

Scrutinizing the use of contrasted chest CTs in extremity sarcoma staging and surveillance

BackgroundSince 2015, the American College of Radiology (ACR) has recommended staging for lung metastasis via chest computed tomography (CT) without contrast for extremity sarcoma staging and surveillance. The purpose of this study was to determine our institutional compliance with this recommendation.MethodsThis was a retrospective chart review of patients diagnosed with sarcoma in the extremities who received CT imaging of the chest for pulmonary staging and surveillance at our institution from 2005 to 2023. A total of 1916 CT studies were included for analysis. We scrutinized ordering patterns before and after 2015 based on the ACR-published metastasis staging and screening guidelines. An institutional and patient cost analysis was performed between CT modalities.ResultsThe prevalence of CT scans ordered and performed with contrast was greater than those without contrast both prior and post-ACR 2015 guidelines. Furthermore, 79.2% of patient's final surveillance CTs after 2015 were performed with contrast. A cost analysis was performed and demonstrated an additional $297 704 in patient and institutional costs.ConclusionsAt our institution, upon review of CT chest imaging for pulmonary staging and surveillance in patients with extremity sarcoma the use of contrast has been routinely utilized despite a lack of evidence for its necessity and contrary to ACR guidelines

One-Stage Synovectomies Result in Improved Short-Term Outcomes Compared to Two-Stage Synovectomies of Diffuse-Type Tenosynovial Giant Cell Tumor (D-TGCT) of the Knee: A Multicenter, Retrospective, Cohort Study

Diffuse-type tenosynovial giant cell tumors\u27 (D-TGCTs) intra- and extra-articular expansion about the knee often necessitates an anterior and posterior surgical approach to facilitate an extensive synovectomy. There is no consensus on whether two-sided synovectomies should be performed in one or two stages. This retrospective study included 191 D-TGCT patients from nine sarcoma centers worldwide to compare the postoperative short-term outcomes between both treatments. Secondary outcomes were rates of radiological progression and subsequent treatments. Between 2000 and 2020, 117 patients underwent one-stage and 74 patients underwent two-stage synovectomies. The maximum range of motion achieved within one year postoperatively was similar (flexion 123-120°, p = 0.109; extension 0°, p = 0.093). Patients undergoing two-stage synovectomies stayed longer in the hospital (6 vs. 4 days, p \u3c 0.0001). Complications occurred more often after two-stage synovectomies, although this was not statistically different (36% vs. 24%, p = 0.095). Patients treated with two-stage synovectomies exhibited more radiological progression and required subsequent treatments more often than patients treated with one-stage synovectomies (52% vs. 37%, p = 0.036) (54% vs. 34%, p = 0.007). In conclusion, D-TGCT of the knee requiring two-side synovectomies should be treated by one-stage synovectomies if feasible, since patients achieve a similar range of motion, do not have more complications, but stay for a shorter time in the hospital

Population Susceptibility to Biological Warfare Agents

What insights can different disciplines and modes of inquiry offer about the legacies of war? How might integration of these insights help us learn more about the impact of war, broadly conceived? And what lessons might be drawn for the future? This presentation on microbial legacies of war is part of Legacies of War and the Liberal Arts: Learning from Difference, a series of short, student-led talks that bring a variety of disciplinary perspectives — sciences, arts, humanities, and social sciences — to bear on arguably the most consequential experiences of human history. Patrick Cottrell, Associate Professor of Political Science at Linfield College, introduces the series of talks at the beginning of the presentation

An Electronic Form for Reporting Results of Targeted Prostate Biopsy: Urology Integrated Diagnostic Report (Uro-IDR).

ObjectiveTo detail the development of an electronic report that graphically conveys all relevant information from targeted prostate biopsy.MethodsThe Urology Integrated Diagnostic Report (Uro-IDR) is based on a published framework (RadPath) which enables the compilation of diagnostic data from urology, radiology, and pathology. Each component of the Uro-IDR is generated by the contributing clinician, is assembled in one document, and provides correlation of the 3 inputs at a glance. Upon completion, the Uro-IDR is automatically linked to the electronic medical record as an interactive file and can also be downloaded for offline sharing as a PDF.ResultsAt our institution, 1638 individual Uro-IDRs were generated between June 2016 and April 2019. There were 5715 views of these documents via the EMR. The average turnaround time for the creation of an individual report decreased from nearly 8 days at the time of its launch to 2 days after 6 months of use. The average time for report generation was 22 seconds for the pathologist and 69 seconds for the radiologist. An instructive video is linked to this article.ConclusionThe Uro-IDR has proven to be a feasible, efficient, clinically useful form to concisely transmit key information about targeted prostate biopsy to both clinicians and patients

Prospective Evaluation of Rate of Fusion with Augment Injectable Bone Graft

Category: Hindfoot; Basic Sciences/Biologics Introduction/Purpose: Augment ® Bone Graft is a mixture of rhPDGF-BB, beta-TCP and bovine collagen which has received FDA approval for use as a substitute for autografts during hindfoot and/or ankle arthrodesis. Although a recent meta analysis demonstrated that the rhPDGF-BB and beta-TCP mixture has comparable CT fusion rates and radiographic union rates to those of autografts, these studies excluded patients with prior joint site arthrodesis. In our study, we specifically use Augment ® Injectable Bone Graft (AIBG) which has only very recently received labeling change approval. The goals of our study are to assess fusions rates in patients who receive AIBG during hindfoot and/or ankle arthrodesis, and then subsequently compare fusion rates between primary vs. revision hindfoot and/or ankle arthrodesis as primary outcomes. Methods: We prospectively enrolled patients aged 18-85 who underwent subtalar, calcaneocuboid, talonavicular, and/or ankle arthrodesis from one of two academic surgeons including both primary and revisions fusions. The patients received AIBG and were excluded if any other graft material was used. Demographic data and patient reported outcomes were collected preoperatively and at follow-up visits including Visual Analog Pain Scale (VAS), Foot Function Index (FFI), Foot and Ankle Ability Measure (FAAM) Sports Subscale, and Veterans Rand 12 (VR-12) physical and mental subscores. Patients were followed at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. The primary outcome measure was fusion rate via CT scan at 4 months with secondary outcomes consisting of the patient reported outcome data and rate of revisions. Results: 62 patients met inclusion criteria, 50 patients had a 4-month postoperative CT scan to assess for fusion with 78% of the CT scans (39 out of 50) demonstrating fusion at that time. There were only 3 revision fusion patients, with 1 of the 3 failing to fuse. 54 of the patients were followed through their 6 month visits, 44 patients through 1 year, and 24 patients were seen for their 2-year follow-up visit. All patient reported outcomes demonstrated improvement from preoperatively to final follow-up with VAS scores improving from 5.52 to 3.21, FFI improving from 57.87 to 35.64, FAAM-sports improving from 18.65 to 29.30, VR-12 Physical improving from 28.67 to 35.18, and VR-12 Mental improving from 44.27 to 47.74. Conclusion: This prospective study demonstrates that Augment ® Injectable Bone Graft is an acceptable alternative to allograft for either primary or revision hindfoot arthrodesis procedures with 78% of patients achieving fusion on a 4-month postoperative CT scan and with steady noted improvement in multiple validated patient-reported outcome measures

The Use of a Sustained Dynamic Compression Intramedullary Nail for Subtalar Arthrodesis

Category: Hindfoot; Other Introduction/Purpose: Subtalar arthrodesis has traditionally been performed using fixation made of titanium or stainless steel. While these devices can provide initial compression, the compressive loads can be lost soon after surgery as bone settling or resorption occurs at the joint spaces. The DynaNail ® Mini is a subtalar arthrodesis intramedullary nail that allows for compression during surgery and has a stretched nitinol element that attempts to contract but is held by talus and calcaneus screws providing sustained dynamic compression across the joint. There is minimal clinical data evaluating the effects of sustained compression devices on isolated subtalar arthrodesis. The goal of this study was to prospectively follow patients undergoing subtalar arthrodesis with the DynaNail ® Mini and evaluate its clinical efficacy via fusion rate and patient reported outcomes. Methods: We prospectively enrolled patients aged 18-85 who underwent subtalar arthrodesis with the DynaNail ® Mini from one of two academic surgeons. Demographic data and patient reported outcomes were collected preoperatively and at follow-up visits including Visual Analog Pain Scale (VAS), Foot Function Index (FFI), Foot and Ankle Ability Measure (FAAM) Sports Subscale, and Veterans Rand 12 (VR-12) physical and mental subscores. Patients were followed at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. The primary outcome measure was fusion rate via CT scan at 4 months with secondary outcomes consisting of the patient reported outcome data and rate of revisions. Results: 21 patients met inclusion criteria, 14 patients had a 4-month postoperative CT scan to assess for fusion with 78.6% of the CT scans (11 out of 14) demonstrating fusion at that time. 20 of the patients were followed through their 6 month visits, 16 patients through 1 year, and 16 patients were seen for their 2-year follow-up visit. All patient reported outcomes demonstrated improvement from preoperatively to final follow-up with VAS scores improving from 5.69 to 3.84, FFI improving from 56.43 to 37.88, FAAM-sports improving from 20.31 to 30.47, VR-12 Physical improving from 28.70 to 34.41, and VR-12 Mental improving from 43.64 to 49.81. Conclusion: This prospective study demonstrates that patients undergoing subtalar arthrodesis with the DynaNail® Mini demonstrate favorable clinical outcomes that are comparable to existing methods of subtalar arthrodesis with 78.6% of patients achieving fusion on a 4-month postoperative CT scan and with steady noted improvement in multiple validated patient-reported outcome measures