Browsing by Author "Demir, Zeynep"

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    Contribution of Alzheimer's biomarkers and risk factors to cognitive impairment and decline across the Alzheimer's disease continuum
    (Wiley, 2022) Tosun, Duygu; Demir, Zeynep; Veitch, Dallas P.; Weintraub, Daniel; Aisen, Paul; Jack, Clifford R., Jr.; Jagust, William J.; Petersen, Ronald C.; Saykin, Andrew J.; Shaw, Leslie M.; Trojanowski, John Q.; Weiner, Michael W.; Alzheimer’s Disease Neuroimaging Initiative; Radiology and Imaging Sciences, School of Medicine
    Introduction: Amyloid beta (Aβ), tau, and neurodegeneration jointly with the Alzheimer's disease (AD) risk factors affect the severity of clinical symptoms and disease progression. Methods: Within 248 Aβ-positive elderly with and without cognitive impairment and dementia, partial least squares structural equation pathway modeling was used to assess the direct and indirect effects of imaging biomarkers (global Aβ-positron emission tomography [PET] uptake, regional tau-PET uptake, and regional magnetic resonance imaging-based atrophy) and risk-factors (age, sex, education, apolipoprotein E [APOE], and white-matter lesions) on cross-sectional cognitive impairment and longitudinal cognitive decline. Results: Sixteen percent of variance in cross-sectional cognitive impairment was accounted for by Aβ, 46% to 47% by tau, and 25% to 29% by atrophy, although 53% to 58% of total variance in cognitive impairment was explained by incorporating mediated and direct effects of AD risk factors. The Aβ-tau-atrophy pathway accounted for 50% to 56% of variance in longitudinal cognitive decline while Aβ, tau, and atrophy independently explained 16%, 46% to 47%, and 25% to 29% of the variance, respectively. Discussion: These findings emphasize that treatments that remove Aβ and completely stop downstream effects on tau and neurodegeneration would only be partially effective in slowing of cognitive decline or reversing cognitive impairment.
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    Experimental Models in Penile Transplantation: Translational Insights and Relevance to Clinical Application
    (Springer Nature, 2024-11-22) Kodali, Naga Anvesh; Janarthanan, Ramu; Sazoglu, Bedreddin; Demir, Zeynep; Dirican, Omer Faruk; Kulahci, Yalcin; Zor, Fatih; Gorantla, Vijay S.; Surgery, School of Medicine
    Animal research is an essential contributor to the medical achievements of the last century. The first step of studying a disease in animals is the development of a model which is relevant to the clinical situation in humans. Thus, a good animal model is the sine qua non of the experimental research. This review aims to assess the contemporary literature on animal models for penile transplantation, examining their applicability and significance in the context of clinical scenarios. We also revisit, evaluate, and emphasize the interesting and important findings of certain animal models to bring the reader up to date from the perspective of allotransplantation. Their current and future clinical applicability and feasibility have been discussed, shedding light on worldwide experience in Vascularized Composite Allotransplantation (VCA).
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    Sex and Gender Differences in Face and Upper Extremity Allotransplantation: A Narrative Review of Implications and Impact
    (Springer Nature, 2025-01-24) Demir, Zeynep; Kodali, Naga Anvesh; Dirican, Omer Faruk; Sazoglu, Bedreddin; Janarthanan, Ra,i; Kulahci, Yalcin; Zor, Fatih; Gorantla, Vijay S.; Surgery, School of Medicine
    Sex and gender differences play a significant role in vascularized composite allotransplantation (VCA), impacting both surgical outcomes and postoperative care. While sex refers to biological distinctions and gender encompasses life experiences and behaviors, both factors are closely interrelated in transplantation. Biological sex differences, such as immune responses, hormonal fluctuations, and anatomical features influence graft adaptation and healing, while both sex and gender-specific factors affect psychological and functional recovery. Studies indicate that men have higher mortality and reoperation rates, whereas women are more susceptible to adverse effects from immunosuppressive therapies. Unlike solid organ transplantation (SOT), which is primarily lifesaving, VCA focuses on life-enhancing outcomes, requiring careful attention to patients' social, psychological, and functional well-being. Lifelong immunosuppression in VCA carries risks, including infections and cancer, complicating patient management. Psychological readiness is crucial for candidate selection and long-term success, with women often expressing greater concerns about outcomes. Although no significant gender differences in functional recovery have been observed, individualized rehabilitation plans based on anatomical and physiological differences remain essential for optimal recovery.