Malignant wound aetiology, diagnosis and management: a case series and literature review.

OBJECTIVE: Malignant wounds develop when neoplastic cells invade the skin either locally or by lymphatic and haematogenous spread. They can present as hard-to-heal wounds and underlying causes include: primary skin cancer; metastasis of extracutaneous primary malignancy; malignant transformation of a hard-to-heal wound; iatrogenic injury; and cutaneous forms of cancers of non-skin origin. High clinical suspicion for a malignant wound should be confirmed with skin biopsy. The aim of this case series is to highlight a combination of both clinically clear cutaneous malignancies and not-so-obvious wounds caused by malignancy. METHOD: This case series examines patients with malignant wounds of varying aetiology and appearance. For each case, we explain the pathophysiology, atypical features, diagnostic approach and treatment. We also discuss types of wound biopsy and general wound management principles. RESULTS: Among the 11 cases analysed using descriptive statistics, median wound duration before presentation at our clinic was one year, while median age at presentation was 65 years. Our case series included the following diagnoses: cutaneous metastasis of invasive ductal carcinoma of the breast (n=2); cutaneous metastasis of colorectal adenocarcinoma (n=1); Marjolin's ulcer (n=1), basal cell carcinoma (BCC) (n=2), primary cutaneous squamous cell carcinoma (SCC) (n=1), metastatic malignant melanoma (n=1), cutaneous T-cell lymphoma (n=1), cutaneous angiosarcoma (n=1), Kaposi sarcoma (n=1) and recurrent tonsillar SCC with osteoradionecrosis (n=1); one case had both BCC and SCC. CONCLUSION: Punch and excisional biopsies were the most frequently used diagnostic techniques. Local wound therapy addressed bleeding, malodour, exudate, pain and infection. However, wound healing is usually achieved once the underlying malignancy is treated. In advanced or metastatic disease, palliative wound care aims to prevent exacerbation of existing wounds and focuses on patient comfort.

Artificial intelligence in virtual standardized patients: Combining natural language understanding and rule based dialogue management to improve conversational fidelity.

INTRODUCTION: Advances in natural language understanding have facilitated the development of Virtual Standardized Patients (VSPs) that may soon rival human patients in conversational ability. We describe herein the development of an artificial intelligence (AI) system for VSPs enabling students to practice their history taking skills. METHODS: Our system consists of (1) Automated Speech Recognition (ASR), (2) hybrid AI for question identification, (3) classifier to choose between the two systems, and (4) automated speech generation. We analyzed the accuracy of the ASR, the two AI systems, the classifier, and student feedback with 620 first year medical students from 2018 to 2021. RESULTS: System accuracy improved from ∼75% in 2018 to ∼90% in 2021 as refinements in algorithms and additional training data were utilized. Student feedback was positive, and most students felt that practicing with the VSPs was a worthwhile experience. CONCLUSION: We have developed a novel hybrid dialogue system that enables artificially intelligent VSPs to correctly answer student questions at levels comparable with human SPs. This system allows trainees to practice and refine their history-taking skills before interacting with human patients.

Preclinical Development of a vWF Aptamer to Limit Thrombosis and Engender Arterial Recanalization of Occluded Vessels.

Endothelial surface and circulating glycoprotein von Willebrand factor (vWF) regulates platelet adhesion and is associated with thrombotic diseases, including ischemic stroke, myocardial infarction, and peripheral vascular disease. Thrombosis, as manifested in these diseases, is the leading cause of disability and death in the western world. Current parenteral antithrombotic and thrombolytic agents used to treat these conditions are limited by a short therapeutic window, irreversibility, and major risk of hemorrhage. To overcome these limitations, we developed a novel anti-vWF aptamer, called DTRI-031, that selectively binds and inhibits vWF-mediated platelet adhesion and arterial thrombosis while enabling rapid reversal of this antiplatelet activity by an antidote oligonucleotide (AO). Aptamer DTRI-031 exerts dose-dependent inhibition of platelet aggregation and thrombosis in whole blood and mice, respectively. Moreover, DTRI-031 can achieve potent vascular recanalization of platelet-rich thrombotic occlusions in murine and canine carotid arteries. Finally, DTRI-031 activity is rapidly (<5 min) and completely reversed by AO administration in a murine saphenous vein hemorrhage model, and murine toxicology studies indicate the aptamer is well tolerated. These findings suggest that targeting vWF with an antidote-controllable aptamer potentially represents an effective and safer treatment for thrombosis patients having platelet-rich arterial occlusions in the brain, heart, or periphery.

Ferric Chloride-induced Canine Carotid Artery Thrombosis: A Large Animal Model of Vascular Injury.

Occlusive arterial thrombosis leading to cerebral ischemic stroke and myocardial infarction contributes to ~13 million deaths every year globally. Here, we have translated a vascular injury model from a small animal into a large animal (canine), with slight modifications that can be used for pre-clinical screening of prophylactic and thrombolytic agents. In addition to the surgical methods, the modified protocol describes the step-by-step methods to assess carotid artery canalization by angiography, detailed instructions to process both the brain and carotid artery for histological analysis to verify carotid canalization and cerebral hemorrhage, and specific parameters to complete an assessment of downstream thromboembolic events by utilizing magnetic resonance imaging (MRI). In addition, specific procedural changes from the previously well-established small animal model necessary to translate into a large animal (canine) vascular injury are discussed.