Use of a Multimodal, Peer-to-Peer Learning Management System for Introduction of Critical Clinical Thinking to First-Year Veterinary Students.

Veterinary medical students need multiple thinking strategies, particularly critical thinking. We used a multimedia, peer review learning management system (CGScholar) to introduce a series of complex, realistic, case-based e-learning modules to help introduce critical thinking to 422 first-year veterinary students through instructor-designed clinical cases. Students developed and published on the CGScholar platform an analysis of a case and conducted anonymous peer reviews of each other's drafts. Instructors selected desirable characteristics of a student's activity to track and provide automatic feedback to students via an analytics dashboard and aster plot that allowed visualization of progress. The dashboard also enabled instructors to view the entire class's performance, highlighting students whose performance was lagging. Online interactions were supplemented by case-specific face-to-face workshop sessions. Our goal was to address the following questions: Does the addition of multimedia to a work (one's own or others') enhance people's ability to understand and convey the material? Does peer review (of one's own and others' work) lead to improvements in the writer's own work? Does the peer review process enhance the writer's understanding of what constitutes high-quality literature evidence? An anonymous student survey showed that experience was significantly more positive in the second and third year of implementation after inclusion of explicit guidance on the use of the rubric for peer review. Overall, 67% of students thought inclusion of multimedia enhanced their ability to communicate and 52% agreed multimedia enhanced their ability to understand their peers' analyses, but students were split on benefits to their understanding of high-quality literature.

Incidence and risk factors for preoperative deep venous thrombosis in 314 consecutive patients undergoing surgery for spinal metastasis.

OBJECTIVE The authors of this study aimed to identify the incidence of and risk factors for preoperative deep venous thrombosis (DVT) in patients undergoing surgical treatment for spinal metastases. METHODS Univariate analysis of patient age, sex, ethnicity, laboratory values, comorbidities, preoperative ambulatory status, histopathological classification, spinal level, and surgical details was performed. Factors significantly associated with DVT univariately were entered into a multivariate logistic regression model. RESULTS The authors identified 314 patients, of whom 232 (73.9%) were screened preoperatively for a DVT. Of those screened, 22 (9.48%) were diagnosed with a DVT. The screened patients were older (median 62 vs 55 years, p = 0.0008), but otherwise similar in baseline characteristics. Nonambulatory status, previous history of DVT, lower partial thromboplastin time, and lower hemoglobin level were statistically significant and independent factors associated with positive results of screening for a DVT. Results of screening were positive in only 6.4% of ambulatory patients in contrast to 24.4% of nonambulatory patients, yielding an odds ratio of 4.73 (95% CI 1.88-11.90). All of the patients who had positive screening results underwent preoperative placement of an inferior vena cava filter. CONCLUSIONS Patients requiring surgery for spinal metastases represent a population with unique risks for venous thromboembolism. This study showed a 9.48% incidence of DVT in patients screened preoperatively. The highest rates of preoperative DVT were identified in nonambulatory patients, who were found to have a 4-fold increase in the likelihood of harboring a DVT. Understanding the preoperative thrombotic status may provide an opportunity for early intervention and risk stratification in this critically ill population.

A proangiogenic signaling axis in myeloid cells promotes malignant progression of glioma.

Tumors are capable of coopting hematopoietic cells to create a suitable microenvironment to support malignant growth. Here, we have demonstrated that upregulation of kinase insert domain receptor (KDR), also known as VEGFR2, in a myeloid cell sublineage is necessary for malignant progression of gliomas in transgenic murine models and is associated with high-grade tumors in patients. KDR expression increased in myeloid cells as myeloid-derived suppressor cells (MDSCs) accumulated, which was associated with the transformation and progression of low-grade fibrillary astrocytoma to high-grade anaplastic gliomas. KDR deficiency in murine BM-derived cells (BMDCs) suppressed the differentiation of myeloid lineages and reduced granulocytic/monocytic populations. The depletion of myeloid-derived KDR compromised its proangiogenic function, which inhibited the angiogenic switch necessary for malignant progression of low-grade to high-grade tumors. We also identified inhibitor of DNA binding protein 2 (ID2) as a key upstream regulator of KDR activation during myeloid differentiation. Deficiency of ID2 in BMDCs led to downregulation of KDR, suppression of proangiogenic myeloid cells, and prevention of low-grade to high-grade transition. Tumor-secreted TGF-ß and granulocyte-macrophage CSF (GM-CSF) enhanced the KDR/ID2 signaling axis in BMDCs. Our results suggest that modulation of KDR/ID2 signaling may restrict tumor-associated myeloid cells and could potentially be a therapeutic strategy for preventing transformation of premalignant gliomas.

Endoscopic diagnosis of an MRI-occult, low-grade glioma with ependymal dissemination.

A 21-year-old man presented with triventricular hydrocephalus due to a tectal mass. He underwent an endoscopic third ventriculostomy, and multiple nodules were identified at the floor of the third ventricle intraoperatively. Surgical pathology of one of these lesions demonstrated that the tissue represented a low-grade astrocytoma. The case highlights the existing potential of neuroendoscopy to reveal neuroimaging-occult lesions, in spite of the significant advances of MRI. Furthermore, the combination of the age of the patient, the nonenhancing MRI appearance, and the multifocality of the lesions constitutes a rare and interesting neoplastic presentation within the brain. The constellation of findings likely represents dissemination of a low-grade tectal glioma via the CSF compartment.

Survival in patients treated for anaplastic meningioma.

OBJECT: While most meningiomas are benign, 1%-3% display anaplastic features, with little current understanding regarding the molecular mechanisms underlying their formation. In a large single-center cohort, the authors tested the hypothesis that two distinct subtypes of anaplastic meningiomas, those that arise de novo and those that progress from lower grade tumors, exist and exhibit different clinical behavior. METHODS: Pathology reports and clinical data of 37 patients treated between 1999 and 2012 for anaplastic meningioma at Memorial Sloan-Kettering Cancer Center (MSKCC) were retrospectively reviewed. Patients were divided into those whose tumors arose de novo and those whose tumors progressed from previously documented benign or atypical meningiomas. RESULTS: Overall, the median age at diagnosis was 59 years and 57% of patients were female. Most patients (38%) underwent 2 craniotomies (range 1-5 surgeries) aimed at gross-total resection (GTR; 59%), which afforded better survival when compared with subtotal resection according to Kaplan-Meier estimates (median overall survival [OS] 3.2 vs 1.3 years, respectively; p = 0.04, log-rank test). Twenty-three patients (62%) presented with apparently de novo anaplastic meningiomas. Compared with patients whose tumors had progressed from a lower grade, those patients with de novo tumors were significantly more likely to be female (70% vs 36%, respectively; p = 0.04), experience better survival (median OS 3.0 vs 2.4 years, respectively; p = 0.03, log-rank test), and harbor cerebral hemispheric as opposed to skull base tumors (91% vs 43%, respectively; p = 0.002). CONCLUSIONS: Based on this single-center experience at MSKCC, anaplastic meningiomas, similar to glial tumors, can arise de novo or progress from lower grade tumors. These tumor groups appear to have distinct clinical behavior. De novo tumors may well be molecularly distinct, which is under further investigation. Aggressive GTR appears to confer an OS advantage in patients with anaplastic meningioma, and this is likely independent of tumor progression status. Similarly, those patients with de novo tumors experience a survival advantage likely independent of extent of resection.

Isolated cortical vein thrombosis: case series.

OBJECT: Isolated cortical vein thrombosis (ICVT) accounts for less than 1% of all cerebral infarctions. ICVT may cause irreversible parenchymal damage, rendering early and accurate diagnosis critical. This case series and literature review presents the clinical and radiological findings in 7 patients with ICVT, and highlights risk factors and imaging modalities that may be most beneficial in rendering an accurate and timely diagnosis. METHODS: Patients with CT and MRI findings consistent with ICVT examined between January 2011 and June 2014 were included in this retrospective review. RESULTS: Seven patients (5 females, 2 males), ranging in age from 11 months to 34 years, met the inclusion criteria. The most common clinical presentations were headaches (n = 4) and seizures (n = 3). The most common comorbidities noted in these patients were hypercoagulable states (n = 4) and intracranial hypotension (n = 3). Five patients had intraparenchymal involvement. CT suggested the correct diagnosis in 4 patients, and MRI confirmed the diagnosis in all 7 patients. All patients who received anticoagulation therapy (n = 5) experienced complete resolution of their symptoms. CONCLUSIONS: The majority of these patients were adult females, consistent with published data. Seizures and headaches were the most common presenting symptoms. Hypercoagulable state and intracranial hypotension, both known risk factors for thrombosis, were the most commonly noted ICVT risk factors. Intraparenchymal involvement was prevalent in nearly all ICVT cases and presented as vasogenic edema, early intraparenchymal hemorrhage, or hemorrhagic venous infarction. Susceptibility-weighted imaging was the most sensitive imaging technique in diagnosing ICVT.

Stereotactic radiosurgery plays a critical role in enhancing long-term survival in a patient with pancreatic cancer metastatic to the brain.

BACKGROUND: Pancreatic cancer is an aggressive disease which metastasizes readily. The presence of brain metastases from pancreatic cancer is rare and it carries a poor prognosis. Our approach to treating these lesions stresses extensive use of stereotactic radiosurgery (SRS), whereas other reports focus on surgical resection. CASE REPORT: Information regarding the patient's clinical history was extracted from a retrospective review of the medical records and imaging studies. The patient survived seven years after his primary diagnosis of pancreatic cancer, and 36 months after diagnosis of metastatic disease to the brain. In addition to surgical resection and the use of multiple chemotherapeutic agents, the patient received six separate radiosurgery treatments. CONCLUSION: We present a case of brain metastasis from pancreatic cancer that is remarkable for an unusually long survivorship and discuss the utility of SRS along with a multimodality treatment approach for dealing with these cases.