Browsing by Author "Madison, Mackenzie"

Now showing 1 - 5 of 5
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    Cell model of DJ-1-associated Parkinson’s Disease
    (2017-10-31) Madison, Mackenzie; Hoang, Quyen; Wang, Mu; Hudmon, Andy
    Parkinson’s disease (PD) is a neurodegenerative disorder characterized by progressive loss of motor function resulting from dopaminergic neuronal death in the substantia nigra pars compacta leading to subsequent decreased striatal dopamine levels. The majority of PD cases are diagnosed as sporadic in nature, however 10% - 15% of patients show a positive family history of the disease. While many genes have been found to be implicated in the familial form of PD, early-onset autosomal recessive PD has been associated with mutations in PARK7, a gene which codes for the protein DJ-1. While there are many proposed roles of DJ-1 across numerous systems, the function of DJ-1 in relation to the development and progression of PD remains largely unclear. A first step towards determining this function is the creation of biologically relevant cell models of PD. The goal of this work was to design a representative cell model of DJ-1-associated PD in order to further study DJ-1 with the intention of elucidating its relevant function in relation of PD pathogenesis.
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    Clinical Decision Support for Patient Cases with Asymptomatic Carotid Artery Stenosis Using AI Models and Electronic Medical Records
    (MDPI, 2025-02-06) Madison, Mackenzie; Luo, Xiao; Silvey, Jackson; Brenner, Robert; Gannamaneni, Kartik; Sawchuk, Alan P.; Surgery, School of Medicine
    An artificial intelligence (AI) analysis of electronic medical records (EMRs) was performed to analyze the differences between patients with carotid stenosis who developed symptomatic disease and those who remained asymptomatic. The EMRs of 872 patients who underwent a carotid endarterectomy between 2009 and 2022 were analyzed with AI. This included 408 patients who had carotid intervention for symptomatic carotid disease and 464 patients for asymptomatic, >70% stenosis. By analyzing the EMRs, the Support Vector Machine achieved the highest sensitivity at 0.626 for predicting which of these patients would go on to develop a stroke or TIA. Random Forest had the highest specificity at 0.906. The risk for stroke in patients with carotid stenosis was a balance between optimum medical treatment and the underlying disease processes. Risk factors for developing symptomatic carotid disease included elevated glucose, chronic kidney disease, hyperlipidemia, and current or recent smoking, while protective factors included cardiovascular agents, antihypertensives, and beta blockers. An AI review of EMRs can help determine which patients with carotid stenosis are more likely to develop a stroke to assist with decision making as to whether to proceed with intervention or to demonstrate and encourage reduced stroke risk with risk factor modification.
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    Impact of time between diagnosis to treatment in Acute Type A Aortic Dissection
    (Springer Nature, 2021-02-10) Matthews, Caleb R.; Madison, Mackenzie; Timsina, Lava R.; Namburi, Niharika; Faiza, Zainab; Lee, Lawrence S.; Medicine, School of Medicine
    There is a paucity of data describing the effect of time interval between diagnosis and surgery for Acute Type A Aortic Dissection. We describe our 8-year experience and investigate the impact of time interval between symptom onset, diagnosis and surgery on outcomes. Retrospective single-center study utilizing our Society of Thoracic Surgeons registry and patient records. Subjects were grouped by time interval between radiographic diagnosis and surgical treatment: Group A (0–4 h), Group B (4.1–8 h), Group C (8.1–12 h), and Group D (12.1 + h). Data were analyzed to identify factors associated with mortality and outcomes. 164 patients were included. Overall mortality was 21.3%. Group C had the greatest intervals between symptom onset to diagnosis to surgery, and also the highest mortality (66.7%). Preoperative tamponade, cardiac arrest, malperfusion, elevated creatinine, cardiopulmonary bypass time, and blood transfusions were associated with increased mortality, while distance of referring hospital was not. Time intervals between symptom onset, diagnosis and surgery have a significant effect on mortality. Surgery performed 8–12 h after diagnosis carries the highest mortality, which may be exacerbated by longer interval since symptom onset. Time-dependent effects should be considered when determining optimal strategy especially if inter-facility transfer is necessary.
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    Preoperative stroke before cardiac surgery does not increase risk of postoperative stroke
    (Springer Nature, 2021-04-27) Matthews, Caleb R.; Hartman, Timothy; Madison, Mackenzie; Villelli, Nicolas W.; Namburi, Niharika; Colgate, Cameron L.; Faiza, Zainab; Lee, Lawrence S.; Medicine, School of Medicine
    The optimal time when surgery can be safely performed after stroke is unknown. The purpose of this study was to investigate how cardiac surgery timing after stroke impacts postoperative outcomes between 2011–2017 were reviewed. Variables were extracted from the institutional Society of Thoracic Surgeons database, statewide patient registry, and medical records. Subjects were classified based upon presence of endocarditis and further grouped by timing of preoperative stroke relative to cardiac surgery: Recent (stroke within two weeks before surgery), Intermediate (between two and six weeks before), and Remote (greater than six weeks before). Postoperative outcomes were compared amongst groups. 157 patients were included: 54 in endocarditis and 103 in non-endocarditis, with 47 in Recent, 26 in Intermediate, and 84 in Remote. 30-day mortality and postoperative stroke rate were similar across the three subgroups for both endocarditis and non-endocarditis. Of patients with postoperative stroke, mortality was 30% (95% CI 4.6–66). Timing of cardiac surgery after stroke occurrence does not seem to affect postoperative stroke or mortality. If postoperative stroke does occur, subsequent stroke-related mortality is high.
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    Trousseau Syndrome in a 25-Year-Old Woman with Occult Colon Malignancy, Lynch Syndrome, and Chronic Thromboembolic Pulmonary Hypertension
    (Allen Press, 2022) Matthews, Caleb R.; Madison, Mackenzie; Zhang, Chen; Waters, Joshua; Garcia, Jose P.; Beckman, Daniel; Surgery, School of Medicine
    We present a rare case of thrombosis associated with an occult colon malignancy (Trousseau syndrome) in a 25-year-old woman who also presented with previously unidentified Lynch syndrome and acute-on-chronic thromboembolic pulmonary hypertension. Staged treatment included bilateral pulmonary endarterectomy under deep hypothermic circulatory arrest, followed 11 days later by laparoscopic subtotal colectomy and creation of a primary anastomosis. The patient tolerated both procedures well and recovered normal functional status. Final pathologic analysis of the resected colon mass revealed a pT3N0, stage IIA adenocarcinoma; no adjuvant therapy was administered. At her one-year follow-up visit, the patient was cancer-free, remained on lifelong apixaban anticoagulation, and was undergoing routine monitoring and genetic counseling. This case highlights the need for multidisciplinary management of a patient with severe chronic thromboembolic pulmonary hypertension and a concomitant malignancy.