Browsing by Author "O’Leary, Heather A."

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    Contribution of electromechanical coupling between KV and CaV1.2 channels to coronary dysfunction in obesity
    (Springer, 2013) Berwick, Zachary C.; Dick, Gregory M.; O’Leary, Heather A.; Bender, Shawn B.; Goodwill, Adam G.; Moberly, Steven P.; Kohr Owen, Meredith; Miller, Steven J.; Obukhov, Alexander G.; Tune, Johnathan D.; Cellular and Integrative Physiology, School of Medicine
    Previous investigations indicate that diminished functional expression of voltage-dependent K(+) (KV) channels impairs control of coronary blood flow in obesity/metabolic syndrome. The goal of this investigation was to test the hypothesis that KV channels are electromechanically coupled to CaV1.2 channels and that coronary microvascular dysfunction in obesity is related to subsequent increases in CaV1.2 channel activity. Initial studies revealed that inhibition of KV channels with 4-aminopyridine (4AP, 0.3 mM) increased intracellular [Ca(2+)], contracted isolated coronary arterioles and decreased coronary reactive hyperemia. These effects were reversed by blockade of CaV1.2 channels. Further studies in chronically instrumented Ossabaw swine showed that inhibition of CaV1.2 channels with nifedipine (10 μg/kg, iv) had no effect on coronary blood flow at rest or during exercise in lean swine. However, inhibition of CaV1.2 channels significantly increased coronary blood flow, conductance, and the balance between coronary flow and metabolism in obese swine (P < 0.05). These changes were associated with a ~50 % increase in inward CaV1.2 current and elevations in expression of the pore-forming subunit (α1c) of CaV1.2 channels in coronary smooth muscle cells from obese swine. Taken together, these findings indicate that electromechanical coupling between KV and CaV1.2 channels is involved in the regulation of coronary vasomotor tone and that increases in CaV1.2 channel activity contribute to coronary microvascular dysfunction in the setting of obesity.
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    Factors Associated with Cancer Prevention/Risk Reduction Behaviors among Latinos
    (Springer, 2025) Rawl, Susan M.; Maupome, Gerardo; Golzarri‑Arroyo, Lilian; Parker, Erik; O’Leary, Heather A.; Espinoza‑Gutarra, Manuel R.; Valenzuela, Robin E.; Malloy, Caeli; Haunert, Laura; Haggstrom, David A.; School of Nursing
    Improving understanding of behaviors that increase or reduce cancer risk for different Hispanic groups is a public health priority; such knowledge is sparse in new gateway immigration locations such as Indiana. The aims of this study were to: 1) describe cancer beliefs and cancer preventive/risk reduction behaviors (physical activity, tobacco, and alcohol use) among Hispanic adults; 2) examine differences in cancer beliefs and preventive behaviors by country/territory of birth, socioeconomic status, and area of residence (urban vs. rural); and 3) determine predictors of engagement in cancer prevention and risk reduction behaviors in this population. A cross-sectional online survey targeted adult Indiana residents who identified as Latino, Hispanic, or Spanish recruited using Facebook-targeted advertising. Complete survey data from 1520 respondents were analyzed using descriptive, unadjusted, and adjusted models. The majority of respondents believed they were unlikely to get cancer but held many other fatalistic beliefs about cancer. Only 35.6% of respondents had received the HPV vaccine, 37.6% reported they were currently smoking cigarettes, and 64% reported occasional or frequent drinking of alcohol. Respondents spent an average of 3.55 days per week engaged in moderate exercise. Differences were observed by country/territory of birth, income, and education but not by rural residence status. Predictors of cancer risk/risk reduction behaviors were identified. The Hispanic population in Indiana is diverse and effective interventions for cancer prevention should be culturally targeted based on country/territory of birth and individually tailored based on cancer-related beliefs.
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    Factors Associated with Cancer Prevention/Risk Reduction Behaviors among Latinos in Indiana
    (Research Square, 2022-08-06) Rawl, Susan M.; Maupome, Gerardo; Golzarri-Arroyo, Lillian; Parker, Erik; O’Leary, Heather A.; Espinoza-Gutarra, Manuel R.; Valenzuela, Robin E.; Malloy, Caeli; Haunert, Laura; Haggstrom, David A.
    Purpose: Improving understanding of behaviors that increase or reduce cancer risk for different Hispanic groups is a public health priority; such knowledge is sparse in new gateway immigration locations such as Indiana. The aims of this study were to: 1) describe cancer beliefs and cancer preventive/risk reduction behaviors (physical activity, tobacco, and alcohol use) among Hispanic adults; 2) examine differences in cancer beliefs and preventive behaviors by country of birth, socioeconomic status, and area of residence (urban vs. rural); and 3) determine predictors of engagement in cancer prevention and risk reduction behaviors in this population. Methods: A cross-sectional online survey targeted adult Indiana residents who identified as Latino, Hispanic, or Spanish recruited using Facebook-targeted advertising. Complete survey data from 1520 respondents were analyzed using descriptive, unadjusted, and adjusted models. Results: The majority of respondents believed they were unlikely to get cancer but held many other fatalistic beliefs about cancer. Only 35.6% of respondents had received the HPV vaccine, 37.6% reported they were currently smoking cigarettes, and 64% reported occasional or frequent drinking of alcohol. Respondents spent an average of 3.55 days per week engaged in moderate exercise. Differences were observed by country of birth, income, and education but not by rural residence status. Predictors of cancer risk/risk reduction behaviors were identified. Conclusion: The Hispanic population in Indiana is diverse and effective interventions for cancer prevention should be culturally targeted based on country of birth and individually tailored based on cancer-related beliefs.
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    High-dose sitagliptin for systemic inhibition of dipeptidylpeptidase-4 to enhance engraftment of single cord umbilical cord blood transplantation
    (Impact Journals, 2017-11-27) Farag, Sherif S.; Nelson, Robert; Cairo, Mitchell S.; O’Leary, Heather A.; Zhang, Shuhong; Huntley, Carol; Delgado, David; Schwartz, Jennifer; Zaid, Mohammad Abu; Abonour, Rafat; Robertson, Michael; Broxmeyer, Hal; Medicine, School of Medicine
    Delayed engraftment remains a limitation of umbilical cord blood (UCB) transplantation. We previously showed that inhibition of dipeptidylpeptidase (DPP)-4 using sitagliptin 600 mg daily was safe with encouraging results on engraftment, but inhibition was not sustained. We evaluated the efficacy and feasibility of higher doses of sitagliptin to enhance engraftment of UCB in patients with hematological cancers. Fifteen patients, median age 41 (range, 18-59) years, received single UCB grafts matched at 4 (n=11) or 5 (n=4) of 6 HLA loci with median nucleated cell dose of 3.5 (range, 2.57-4.57) x107/kg. Sitagliptin 600 mg every 12 hours was administered days -1 to +2. All patients engrafted by day 30, with 12 (80%) engrafting by day 21. The median time to neutrophil engraftment was 19 (range, 12-30) days. Plasma DPP-4 activity was better inhibited with a mean residual trough DPP-4 activity of 70%±19%. Compared to patients previously treated with 600 mg/day, sitagliptin 600 mg every 12 hours appeared to improve engraftment, supporting the hypothesis that more sustained DPP-4 inhibition is required. In-vivo inhibition of DPP-4 using high-dose sitagliptin compares favorably with other approaches to enhance UCB engraftment with greater simplicity, and may show synergy in combination with other strategies.