A platform for rapid patient-derived cutaneous neurofibroma organoid establishment and screening.

Localized cutaneous neurofibromas (cNFs) are benign tumors that arise in the dermis of patients affected by neurofibromatosis type 1 syndrome. cNFs are benign lesions: they do not undergo malignant transformation or metastasize. Nevertheless, they can cover a significant proportion of the body, with some individuals developing hundreds to thousands of lesions. cNFs can cause pain, itching, and disfigurement resulting in substantial socio-emotional repercussions. Currently, surgery and laser desiccation are the sole treatment options but may result in scarring and potential regrowth from incomplete removal. To identify effective systemic therapies, we introduce an approach to establish and screen cNF organoids. We optimized conditions to support the ex vivo growth of genomically diverse cNFs. Patient-derived cNF organoids closely recapitulate cellular and molecular features of parental tumors as measured by immunohistopathology, methylation, RNA sequencing, and flow cytometry. Our cNF organoid platform enables rapid screening of hundreds of compounds in a patient- and tumor-specific manner.

The landscape of drug sensitivity and resistance in sarcoma.

Sarcomas are rare malignancies with over 100 distinct histological subtypes. Their rarity and heterogeneity pose significant challenges to identifying effective therapies, and approved regimens show varied responses. Novel, personalized approaches to therapy are needed to improve patient outcomes. Patient-derived tumor organoids (PDTOs) model tumor behavior across an array of malignancies. We leverage PDTOs to characterize the landscape of drug resistance and sensitivity in sarcoma, collecting 194 specimens from 126 patients spanning 24 distinct sarcoma subtypes. Our high-throughput organoid screening pipeline tested single agents and combinations, with results available within a week from surgery. Drug sensitivity correlated with clinical features such as tumor subtype, treatment history, and disease trajectory. PDTO screening can facilitate optimal drug selection and mirror patient outcomes in sarcoma. We could identify at least one FDA-approved or NCCN-recommended effective regimen for 59% of the specimens, demonstrating the potential of our pipeline to provide actionable treatment information.

Mitral Annular Disjunction: A Scoping Review.

Mitral annular disjunction (MAD) is the atrial displacement of the mitral valve (MV) hinge point, especially along the posterior mitral leaflet, which leads to inhomogeneous blood flow into the left ventricle, causing chronic fibrotic changes, malignant arrhythmias, and even sudden cardiac arrest. Some studies suggest that MAD is a part of normal heart morphology; however, the origin is still controversial. MAD commonly occurs with MV prolapse and myxomatous degenerative MV disease. In almost 20% of cases, MAD can occur independently as well. The prevalence of MAD in normal hearts varies from 8.6% to 96%, depending on the imaging modality and the cutoff used to define MAD. Transthoracic echocardiography is often the initial screening test, but the low sensitivity of transthoracic echocardiography to identify MAD makes it easy to miss the diagnosis altogether. More advanced imaging, especially cardiac MRI, is the gold standard for diagnosing MAD and risk stratification. MAD is an independent predictor of malignant arrhythmia. Among patients with MAD, risk stratification is based on the age at diagnosis, previous syncopal attacks, premature ventricular contractions, papillary muscle fibrosis, and longitudinal disjunction distance. Most asymptomatic patients are managed conservatively; however, radiofrequency ablation should be considered in patients with high-risk or symptomatic MAD due to the risk of ventricular arrhythmias and sudden cardiac death.

Effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking medical students.

Background: Peer-assisted learning has been shown to be constructive in numerous aspects of undergraduate medical education. The purpose of this study was to evaluate the effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking students. Methods: A medical English conversation course was conducted at Damascus University by a group of students. Targeted participants were intermediate level fellow students from the same program. A longitudinal study was carried out between 1 st to 31 st March 2019 to assess changes in self-assessment of English language skills among course participants. Pre- and post-course appraisal involved a review of previous experience with medical English language, a self-assessment of five English language skills, and an objective measurement of medical English knowledge. In addition, participants were requested to respond to a set of statements related to the importance and the usefulness of peer-assisted teaching of medical English skills. Paired-sample Student t-test was used to compare pre- and post-course appraisal results. Results: 42 students attended the course and completed pre- and post-course appraisals in full. Data analyses showed a statistically significant increase in participants' confidence in speaking medical English in public ( p<0.001) and using English in various medical settings (presenting and discussing cases, writing clinical reports, interviewing patients and reading English medical texts). Objective measurements of medical English knowledge confirmed a significant increase in participants' knowledge of methods of administration of therapeutics, knowledge of human body parts in English and familiarity with English medical abbreviations. Most participants agreed that peer-education was effective in teaching medical English skills to non-native English-speaking students and in increasing their confidence when using English in real-life medical scenarios. Conclusions: The present study highlights the effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking medical students. Further validation is required and should compare the effectiveness of traditional versus peer-assisted teaching approaches.

The landscape of drug sensitivity and resistance in sarcoma.

Sarcomas are a family of rare malignancies composed of over 100 distinct histological subtypes. The rarity of sarcoma poses significant challenges in conducting clinical trials to identify effective therapies, to the point that many rarer subtypes of sarcoma do not have standard-of-care treatment. Even for established regimens, there can be substantial heterogeneity in responses. Overall, novel, personalized approaches for identifying effective treatments are needed to improve patient out-comes. Patient-derived tumor organoids (PDTOs) are clinically relevant models representative of the physiological behavior of tumors across an array of malignancies. Here, we use PDTOs as a tool to better understand the biology of individual tumors and characterize the landscape of drug resistance and sensitivity in sarcoma. We collected n=194 specimens from n=126 sarcoma patients, spanning 24 distinct subtypes. We characterized PDTOs established from over 120 biopsy, resection, and metastasectomy samples. We leveraged our organoid high-throughput drug screening pipeline to test the efficacy of chemotherapeutics, targeted agents, and combination therapies, with results available within a week from tissue collection. Sarcoma PDTOs showed patient-specific growth characteristics and subtype-specific histopathology. Organoid sensitivity correlated with diagnostic subtype, patient age at diagnosis, lesion type, prior treatment history, and disease trajectory for a subset of the compounds screened. We found 90 biological pathways that were implicated in response to treatment of bone and soft tissue sarcoma organoids. By comparing functional responses of organoids and genetic features of the tumors, we show how PDTO drug screening can provide an orthogonal set of information to facilitate optimal drug selection, avoid ineffective therapies, and mirror patient outcomes in sarcoma. In aggregate, we were able to identify at least one effective FDA-approved or NCCN-recommended regimen for 59% of the specimens tested, providing an estimate of the proportion of immediately actionable information identified through our pipeline. Highlights: Standardized organoid culture preserve unique sarcoma histopathological featuresDrug screening on patient-derived sarcoma organoids provides sensitivity information that correlates with clinical features and yields actionable information for treatment guidanceHigh-throughput screenings provide orthogonal information to genetic sequencingSarcoma organoid response to treatment correlates with patient response to therapyLarge scale, functional precision medicine programs for rare cancers are feasible within a single institution.

Personalized chordoma organoids for drug discovery studies.

Chordomas are rare tumors of notochordal origin, most commonly arising in the sacrum or skull base. Chordomas are considered insensitive to conventional chemotherapy, and their rarity complicates running timely and adequately powered trials to identify effective treatments. Therefore, there is a need for discovery of novel therapeutic approaches. Patient-derived organoids can accelerate drug discovery and development studies and predict patient responses to therapy. In this proof-of-concept study, we successfully established organoids from seven chordoma tumor samples obtained from five patients presenting with tumors in different sites and stages of disease. The organoids recapitulated features of the original parent tumors and inter- as well as intrapatient heterogeneity. High-throughput screenings performed on the organoids highlighted targeted agents such as PI3K/mTOR, EGFR, and JAK2/STAT3 inhibitors among the most effective molecules. Pathway analysis underscored how the NF-κB and IGF-1R pathways are sensitive to perturbations and potential targets to pursue for combination therapy of chordoma.

Multimodality Imaging and Percutaneous Closure of Right Sinus of Valsalva to Right Ventricular Outflow Tract Fistula After Transcatheter Aortic Valve Replacement.

We present the diagnosis and treatment of a 90-year-old male with critical aortic stenosis and multiple medical comorbidities who underwent TAVR that was complicated by annular rupture.